Marys Medicine

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COST Action E54
Characterisation of the fine structure and properties of
papermaking fibres using new technologies
16–17 October 2008
COST is supported by
the EU RTD Framework Programme


Felelős szerkesztő: Polyánszky Éva
Titkár: Lindner György
Folyóiratunknak ez a száma a Papyrus Hungária Zrt. által forgalmazott 115 g/m2-es G-Print papíron készült.
A PAPÍR- ÉS NYOMDAIPARI MŰSZAKI EGYESÜLET KIADVÁNYUNK TELJES SZÖVEGÉT AZ ORSZÁGOS SZÉCHÉNYI KÖNYVTÁR ELEKTRONIKUS PERIODIKA ARCHÍVUMA (EPA) ARCHÍVÁLJA(http://epa.oszk.hu/papiripar) LII. évfolyam, 6. szám, 2008.
PAPÍRGYÁRTÁSBAN HASZNÁLT ROSTOK FINOMSZER- CHARACTERISATION OF THE FINE STRUCTURE AND KEZETÉNEK ÉS TULAJDONSÁGAINAK JELLEMZÉSE ÚJ PROPERTIES OF PAPERMAKING FIBRES USING NEW 206 A. Treimanis: Előszó 207 A. Treimanis: Preface 208 Polyánszky É.: Különkiadás 209 É. Polyánszky: Special issue 210 Szikla Z.: A Dunapack-Hamburger dunaújvárosi gyárának és 211 Z. Szikla: Paper Industry in Hungary az új csomagolópapírt gyártó gép projektjének bemutatása 215 A. Hernádi – I. Lele: Research activity in the field of fine 214 Hernádi S., Lele I.: Kutatási tevékenység a cellulózrostok structure of cellulose fibres in PRI Budapest finomszerkezetének területén a Papíripari Kutatóintézetben 219 I. Tánczos: Pyrolysis-Gas Chromatography-Mass Spectros- (PKI) – Budapest copy and its use for the analysis of wood pulp fibres and their 218 Tánczos I.: Pirolízis gázkromatográfia-tömegspektrometria és a módszer használata fa, farost, szálasanyagok és ezek származékainak vizsgálatára 1. MUNKACSOPORT – Különböző kezelések hatása a papír- WORKING GROUP 1. – Structure and chemical composition ipari rostok szerkezetére és kémiai összetételére of papermaking fibres after different types of treatment 224 A. Treimanis – A. Potthast – U. Henniges – T. Roseanu – U. 225 A. Tremanis – A. Potthast – I. Henniges – T. Roseanu Grinfelds – T. Bukova – M. Skute: Mechanikailag leválasztott – U.Grinfelds – T. Bukova – M.Skute: Analysis of surface layers fehérítetlen és fehérített eukaliptusz kraftcellulóz rostok felületi of mechanically peeled unbleached and bleached eucalyptus rétegeinek elemzése kraft pulp fibres 230 R. Eckhart – M. Donoser – W .Bauer: Újonnan kifejlesztett 231 R. Eckhart – M. Donoser – W. Bauer: A Newly developed módszer az egyedi rost rugalmasságának méréséhez Method for Single Fiber Flexibility Measurement 234 T. Larsson, C. Vasile: Cellulóz szupramolekuláris 235 T. Larsson, C. M. Popescu, C.Vasile: A comparative CP/MAS szerkezetének szilárd fázisú NMR és Röntgen-diffrakciós 13C-NMR and XRD study of the cellulose supra-molecular összehasonlító vizsgálata fenyő kraftcellulóz roston structure in softwood kraft pulp fibres 2. MUNKACSOPORT – Egyedi rostok kezelése és jellemzé- WORKING GROUP 2. – Treatment and characterisation of individual fibres by microsystem technologies 238 P. Ander és G. Daniel: Cellulózrostok vizsgálata sósavval, 239 P. Ander, G. Daniel: Testing of pulp fibres with HCl, phosphoric foszforsavval és cellulázzal acid and cellulase 245 R. B. Adusumalli: Egyedi cellulózrostok mikromechanikája 245 R. B. Adusumalli: Micromechanics of single pulp fibres 246 L. Kappel, U. Hirn, W. Bauer, R. Schennach: Az egyedi rost- 247 L. Kappel, U. Hirn, W. Bauer, R. Schennach: Measuring the rost kötések kötési területének mérése bonded area of individual fiber-to-fiber bonds 3.MUNKACSOPORT – Rostok finomszerkezetének hatása WORKING GROUP 3. – The impact of the fine structure of papírképző tulajdonságaikra, valamint kémiai és enzimatikus fibres on their papermaking properties and their chemical and reaktivitásukra enzymatic reactivity 252 J. Valchev, P. Bikov: Rostanyagok víztelenítése és az őrlés 253 I. Valchev, P. Bikov: Pulp dewatering and refining efficiency hatékonyságának javítása celluláz kezeléssel improvement by cellulase treatment 258 M. Lecourt,P. Nougier,A. Soranzo,S. Tapin-Lingua, M. Petit- 259 M. Lecourt, P. Nougier, A. Soranzo, S. Tapin-Lingua, M. Petit- Conil: Hogyan hat az enzimes kezelés a rost tulajdonságaira? Conil: How do enzymatic treatments affect fibre properties? 264 T. Arndt, G. Meinl, K. Erhard: Cellulózrostok finomszerkezeté- 265 T. Arndt, G. Meinl, K. Erhard: Behaviour of cellulose fine nek viselkedése papírgyártási vizsgálatokban structures in papermaking tests 270 Lele I., Víg A.: ZÁRSZÓ 271 I. Lele, A.Víg: Epilogue


Először is szeretném MCS2: Egyedi rostok kezelése és jellemzésük
megköszönni a „Papíripar" szerkesztőbizottságának, hogy megjelenteti az EU Ez a Munkacsoport új eszközök kidolgozásá- E54 COST Akció 2008. ra fókuszál, nevezetesen a mikrotechnológiákra, október 16-17-én Buda- melyekkel az egyedi rostokat kezelni lehet, és a pesten „Papírgyártásban
rostszerkezeteket laboratóriumi körülmények között használt rostok finom-
lehet vizsgálni.
szerkezetének és tulaj-
donságainak jellemzése
új technológiákkal"
cím-
MCS3: Rostok finomszerkezetének hatása
mel megtartott szakszemi- papírképző tulajdonságaikra, valamint kémiai és
Prof. Arnis Treimanis náriumának előadásait. Az E54 COST Akció 2006-ban indult és 2010. decemberig tart. Máig 19 A 3. Munkacsoport kutatói és szakértői tapaszta- ország csatlakozott az Akcióhoz, és számos, a COST- latot cseréltek a rostok finomszerkezetének és módo- ban nem résztvevő ország tudósai fejezték ki kíván- sításaiknak a belőlük gyártott papírok tulajdonságai- ságukat, hogy bekapcsolódjanak a projekt tevékeny- ra gyakorolt hatásáról. A munka lényege különböző kérdésekre koncentrált: Az E54 Akció fő célkitűzése az, hogy új isme- reteket szerezzünk a papíripari rostok mikro- és • milyen hatást gyakorolnak a kémiai mechaniz- nanoszerkezetéről, és a rostok hatékony és fenntart- musok a rostok nano-felületén (azaz például ható felhasználásához szükséges tulajdonságokról a a maradék lignin, hemicellulóz és funkcionális hagyományos és az új termékekben.
csoportok mennyisége és elhelyezkedése) a fon- Örömömre szolgál, hogy arról tájékoztathatom tosabb rosttulajdonságokra, és ezt hogyan lehet Önöket, hogy az Akció eddigi kétéves periódusa alatt értelmezni a papír minőségére vonatkozóan? számos nagyon érdekes megközelítést és módszert • a rostfelületek mechanikai paraméterei, mint dolgoztak ki az Akció résztvevői. Ennek egy része tük- pl. a rostfal vastagsága, a rostfal porozitása, röződik az újságnak ebben a kiadásában.
valamint keménysége hogyan hat a rost tulaj-donságaira és így a végső papírtermékre? Az E54COST Akció három munkacsoportot (MCS) A három munkacsoport között kapcsolat alakult ki és ezt fenn is kell tartani, mivel minden szempont fontos a papírgyártásban használt rostok finomszer- MCS1: Különböző kezelések hatása a papíripari
kezetének és kémiájának jobb megértéséhez.
rostok szerkezetére és kémiai összetételére
Végezetül szeretném megköszönni az E54 COST A Munkacsoport tevékenységének célja, hogy Akció Budapesten megtartott szakszemináriuma helyi • új jellemzési és értékelési módszereket fejlesz- szervezőinek a kiváló munkát, mellyel biztosították a nagyon sikeres és gyümölcsöző tanácskozást. Közülük • új adatokat gyűjtsön és generáljon a papír- szeretném megemlíteni Dr. Víg András, Lele István, gyártásban használt rostok finomszerkezetére Szőke András, Pesti Sándor és Dr. Szikla Zoltán urakat.
vonatkozóan, olyan körülmények között, ahogy ezeket az ipari folyamatokban előállítják.
Az Akció következő ülésére Tamperében, Finnor- szágban kerül sor, 2009. május 4-6 között.
A Munkacsoport tevékenysége a rostok finom- és nanoszerkezetére koncentrál a leginkább releváns Prof. Arnis Treimanis, Riga, Lettország ipari kezelési, elsősorban rostosítási, fehérítési, őrlési a COST E54 Akció elnöke és recycling technikákat követően.


First of all I would like to thank the Editorial Board WG3. The impact of the fine structure of fibres
of the journal „Papíripar" for its kind consent to pub- on their papermaking properties and their chemi-
lish the proceedings of the EU COST Action E54 „Char-
cal and enzymatic reactivity
acterisation of the fine structure and properties
of papermaking fibres using new technologies"

The scientists and experts of WG3 exchange their Workshop in Budapest 16-17 October 2008. experience with respect to the impact of the fine COST Action E54 started in 2006 and will last till structure of fibres and their modification on the qual- December 2010. Now 19 countries have joined the ity of the paper produced thereof. The emphasis of Action, and the scientists from several COST non-par- the work is focused on different questions: ticipating institutions have expressed their wish to enroll in the project activities.
• what is the impact of the chemical mechanisms The main objective of the Action E54 is to gener- at the nano-surface of fibres, i.e. the amount ate new knowledge on the micro- and nanostructure and localisation of, for example, residual lignin, of papermaking fibres and properties required for hemicelluloses and functional groups, on efficient and sustainable use of fibres in traditional major fibre properties and how does this trans- and new products.
late into paper quality? It is my pleasure to note that during two years of the • how will mechanical parameters of fibre sur- Action's time span several very interesting approaches faces such as fibre wall thickness, fibre wall and methods were developed by the Action's partici- porosity as well as hardness influence the fibre pants. Part of them is reflected in this journal issue.
properties and thus that of the final paper product? COST Action E54 comprises three working The links between the three working groups are created and have to be maintained since all aspects are important for a better understanding of the fine WG1: Structure and chemical composition of
structure and chemistry of papermaking fibres.
papermaking fibres after different types of treat-
ments

Finally I would like to cordially thank the local organizers of the COST Action E54 Workshop in The objective of the activities of this WG is to Budapest for their excellent work to guarantee a • develop new methods for the characterisation very successful and fruitful meeting. Among them and assessment, and I would like to mention Dr. András Víg, Mr. István • to accumulate and generate new data on the Lele, Mr. András Szőke, Mr. Sándor Pesti, Mr. Zoltán fine structure of fibres for papermaking as they are produced in industrial processes.
Next meeting of the Action takes place in Tam- The activities of this WG are focused on the fine pere, Finland, 4-6 May, 2009.
and nano-structure of the fibres after the most rel- evant industrial treatment techniques, in particular Chairman of the COST Action E54 pulping, bleaching, beating and recycling.
Prof. Arnis Treimanis, Riga, Latvia. WG2: Treatment and characterisation of indi-
vidual fibres by microsystem technologies
This WG is focused on the development of new instruments namely microsystem technologies by which individual fibres can be treated and fibre struc-tures can be investigated at laboratory scale.


is találkozhattam, akikkel a 90-es évek elejétől egyesületünk PAPÍR- több mint 10 éven át – Magyarország COST IPAR c. lapja számára, képviselőjeként – együttműködhettünk szá- hogy egy nemzetközi mos közös kutatásban az életciklusanalízistől kutatási együttműkö- az elfolyásmentes papírgyártásig stb, melyek dés (COST E54 akció) mindegyikének eredményei alapvető fontossá- 2008 október 16–17- gúak a papírgyártásban. iki budapesti üléséről Magyar olvasóinknak biztosan feltűnik, hogy az újság szerkezete eltér az utóbbi időben megszokottól. Az akció és a konferencia beosz- ban 19 európai ország, tása szerint munkacsoportonként mutatjuk be Polyánszky Éva köztük Magyarország 12 előadás rövidített változatát angolul, illetve működik együtt, hogy magyar összefoglalóval azok számára, akiknek minden partner a saját tudását, műszereit latba az angol szakszöveg esetleg gondot okozna. vesse egy közös cél érdekében: ismerjük meg Ez a szám különleges tehát, de a következő minél alaposabban a cellulózrost azon tulaj- is feltehetően is az lesz, mert semmi sem örök, donságait, meíyek felelősek a papírgyártás csak a változás.
során a rostok viselkedéséért. A végső cél Újságunk jövő évi megjelenése – gazdasá- pedig a minél jobb minőségű papír előállítása.
gi és szakmai okok miatt – nagy valószínűség- Alapító főszerkesztőnk, Dr. Vámos György gel sok újdonsággal szolgál majd olvasóink biztos örömmel venné kézbe ezt az újságot, mely a klasszikus kutatás nemzetközi együttmű-ködésben létrehozott eredményeit mutatja be. Polyánszky Éva Személy szerint számomra külön öröm, hogy a konferencia során az akció olyan résztvevőivel Technical Association of Paper and Printing Industry – Budapest pnyme@mtesz.hu – www.pnyme.hu


It is an honour for the journal of our Asso- research projects, from "life cycle assessment" ciation „PAPÍRIPAR" to report on the ses- through "papermaking towards zero liquid efflu- sion of an international research co-opera- ent" etc., the results of which are of basic impor- tion (COST Action E54) held in Budapest on tance in papermaking.
16-17 October 2008. There are 19 European Our Hungarian readers will probably realize countries including Hungary co-operating so that the structure of the journal differs from that that each partner contributes his knowledge, of the ordinary appearance. According to the instruments serving one common goal: to be Action and Conference schedule an abbrevi- more and more familiar with the properties of ated version of twelve papers will be introduced the cellulose fibre that are responsible for the by Working Groups in English and with summa- behaviour of fibres during papermaking. The ry in Hungarian for those whom the understand- final objective is the production of paper of the ing of the English technical text would cause possible highest quality.
difficulties. This issue will be thus a special one Our founder and editor-in-chief, Dr. George but presumably the next one will be the same Vámos would be happy to take this journal in since nothing is eternal but the changes.
his hands demonstrating the results achieved in The appearance of our journal in the next international co-operation of a classic research. year, due to economic and professional reasons For me personally it is a special privilege that will, most probably, furnish our readers with lot during the conference I could meet participants of novelties.
of the Action whom I had the chance, in my capacity of Hungary's COST-representative, to Éva Polyánszky work together over more than ten years from redactor in chief the beginning of the nineties, in several joint


MEGHÍVOTT ELŐADÓK A Dunapack-Hamburger dunaújvárosi gyárának
és az új csomagolópapírt gyártó gép
Dr. Szikla Zoltán Dunapack Zrt. elnökhelyettese H-1215-Budapest, Duna u. 42.
A Prinzhorn csoport annak határidős megvalósítása a legjobb ütem- bemutatása vezeti be az előadást. Bemutatásra kerül a magyarorszá-gi papírgyártásban és papírfeldolgozásban való domináns szerepe. Az Az október 14-i bokrétaünnepségen – ame- elmúlt évben a csoport lyen a tulajdonos Thomas Prinzhorn is részt vett árbevételének több mint – Galli Miklós, a Dunapack Zrt vezérigazgatója 28%-a származott más arról is beszélt, hogy a pénzügyi válság közve- közép- és kelet-európai tetten érintheti ugyan a céget, de a beruházást Dunapack leányvállala- Szikla Zoltán toktól. Az előadó a Duna- Braunecker Antal, a társaság értékesítési igaz- újvárosi telephely jelen- gatója pedig azt hangsúlyozta, hogy a régióban legi és jövőbeli struktúráját mutatja be. Itt a Ham- szükség van egy ilyen kapacitású gyár felépítésére. burger Hungária Kft. új gépének felfutása után a Magyarországon ugyanis ma kb. 500.000 tonna jövő évben 520.000 t/év papírgyártó kapacitás áll hulladékpapírt gyűjtenek be. Az új gyár évente rendelkezésre. A 205 millió eurós beruházás szíve 400.000 tonnát hasznosít majd, az ország hulla- a 7,8 m széles papírgép, konstrukciós sebessége dékpapír termelésének nagy részét feldolgozza. 1.500 m/perc, barna 70–150 g/m2 hulladékalapú Bencs Attila projektvezető a bokrétaünnepsé- csomagolópapírokat fog gyártani. A technológia gen felidézte, hogy az új üzem alapkövét tavaly néhány technikai részlete mellett a hallgatóság a novemberben rakták le, idén szeptemberben pedig hulladékpapír-forgalomról is kap adatokat.
megkezdődött a gyártó berendezések telepítése, szerelése. A próbaüzemelést jövő év májusára tervezik a szakemberek, 2009. júliusában pedig a Gyárlátogatás a COST E54 programjában
tervek szerint elindul a papírtermelés. Ez a fejlesztés az eddigi legnagyobb magán- A Cost 54 akcióprogram magyarországi ülése erős környezetvédelmi beruházás Magyarorszá- során az érdeklődők közel 40 fős csapata meg- gon, amelynek révén az ország teljesíteni tudja látogatta a Dunapack Ltd Dunaújvárosi Gyárát. az Európai Uniós irányelvekben Magyarországra A látogatás aktualitását az adta, hogy pont az ülés megnyitását megelőző napokban tartották Közép-Kelet Európa legnagyobb papíripari beru- Az új papírgép a felhasználók igényei szerint házásának bokrétaünnepségét. A gyárlátogatás különlegesen vékony és könnyű csomagolópapírt során a látogatók meggyőződhettek a meglévő fog gyártani – 70 és 150 g közötti négyzetméter- egység működési körülményeiről, mely éppen súlyban –, közel nyolc méter szélességű teker- akkor 100 g/m2-es hullámosított réteget 900 csekben, a termékek széles skálájának biztonsá- méter feletti sebességgel gyártott, valamint meg- gos csomagolására. tekinthették az új papírgép építészeti eredményeit Az üzem mintegy 280 főnek biztosít munkát is. Meggyőződhettek arról, ahogy az alábbiakban közvetlenül, de a beruházás megvalósulása révén idézett kiadott sajtóközlemény nemcsak reáli- a térségben további mintegy 600 fő számára oldó- san ambiciózus célokat fogalmazott meg, hanem dik meg a foglalkoztatottság. Paper Industry in Hungary
Dr. Zoltán Szikla Vice President of Dunapack Paper and Packagings Ltd.
Hungary-1215-Budapest, Duna u. 42.
2 and 3, Schrenz in the range of 70-150 g/qm, a waste paper and a finished good store for The Prinzhorn Group is an international pri- approx. two weeks of production. The planned vate owned paper and packaging producer. Its production speed reaches 1350 m/min with 7,8 turnover amounted last year to 1094 million €. m trimmed width. Foundation works started The production capacities reach 1.150.000 t in November 2007 and start up is targeted in containerboard, 565.000 t corrugated prod- June 2009. The investment costs reach 205 ucts and 183.000 t label paper. The concern million €. The machinery takes about 60% of employs 3.779 people in 9 European countries. that. The main suppliers are The Dunapack Group's share from the total capacity is 26% in the paper business and 59% in the converting business. In Hungary there are two paper mills totally with 310.000t/a containerboard capacity and three corrugating mills with 155.000 t/a capacity.
In 2007 Dunapack's Hungarian share was above 55% both in the total paper produc- tion and in the corrugated production. The change of the Hungarian paper and board The new stores of the mill will have a direct production and consumption in the last few connection to the existing systems on both years is shown in Fig. 1. Fig. 2 shows figures
sides, to the recovered paper side and to the of the corrugated board industry in the same automatic roll warehouse. The stock prepara- tion – with a conventional pulper, high and low The biggest still running papermachine in consistency cleaning, fractionating – has ele- Hungary is the PM3 in Dunaújváros/Dunapack. ments which have already been approved in the The annual capacity for 100% recycled cor- existing mills. The paper machine has a Duo- rugated medium is 170.000 t. The corrugating machine at that site had a capacity of 61 million Paper consumption and production in
qm. At the Dunaújváros site of Dunapack 250 people are employed.
Investment of Hamburger Hungaria Ltd
At that site the investment of the new paper- machine of the Prinzhorn Group is on stream. The project is managed by the subsidiary Hamburger Hungaria Ltd. The main items and targets of the project are a paper machine with 350.000 t/a capacity for Wellenstoff, Testliner PICTURES FROM THE MEETING packaging industry. The lightweight container- Consumption and production of
board production will come nearer to the mar- corrugated boxes in Hungary
ket where the biggest growth is forecasted for
the common years. The investment involves
environmental goals, too. As the Fig. 3 shows
Dunapack/Hamburger will certainly remain the
biggest user of the domestic packaging waste in
Hungary, even in the case, if the volume of the
collected recovered paper will grow in measure
represened in the figure.
The increase of the collection of recov- ered paper shows that after a shorter period of import necessity the Hungarian collection and the closed region can cover the demand
of the new machine on commodity grades. See
Fig. 4.

Recovered paper market in Hungary
The growth of the recovered paper collec- tion, the containerboard and corrugated board production, consumption was since the mid-dle of the nineties continuous. The increasing demand on modern packaging makes neces-sary to start production of new light weight RCCM grades in the region. The trend and the must of growing recovered paper collec-tion makes possible to use Hungarian tradition Recovered paper supply by source
of papermaking at Dunaújváros in economical size with the new PM7 from Hamburger Hun-garia ltd.
Former Masterjet II former, a three nip Nipcoflex press with shoe press nip, combined drying with one and two raw drying cylinder, a Speed Sizer as filmpress.
With this new machine – the only new one in the last decades in the Central-Eastern-Euro-pean region- a big gap will be closed for the MEGHÍVOTT ELŐADÓK Kutatási tevékenység a cellulózrostok
a Papíripari Kutatóintézetben (PKI) Budapest
Hernádi Sándor – Lele István Papíripari Kutatóintézet Kft.
H-1215 Budapest, Duna u. 57.
Tel: (36-1)-277-37-50, Fax: (36-1)-276-59-21 A rostok szerkezetét vizsgáltuk többek – Higany poroziméterrel– Letapogató elektronmikroszkóppal (SEM)– Különböző módszerek használatával a Különböző alapanyagok, valamint papírok és töltőanyagok pórusszerkezetét vizsgáltuk. Különböző facellulózok és egynyári növények Hernádi Sándor Lele István póruseloszlását és pórusátmérőjét mértük. Majd a papírlapok pórusait osztályoztuk méret szerint. A Papíripari Kutatóintézetet 1949-ben ala- Megállapítottuk, hogy a papírlapok három külön- pították mint önálló kutatási szervezetet, amely böző pórussal, makropórussal, mikropórussal a cellulóz- és papírgyártás, nyomtatás és a és szubmikropórussal rendelkeznek.
kapcsolódó iparágak területén fellépő problé-mákkal foglalkozott.
SEM technikát alkalmaztunk a cellulózros- Az intézetet 1991-ben magántulajdonú tok felületének vizsgálatához: Jelenleg az intézet a következő szolgálta- – különböző kezeléseket, illetve tásokat nyújtja a cellulóz- és papíripar, papír- – rostfrakcionálást követően. feldolgozás és nyomtatás területén működő vállalatok és intézmények számára: Példaként néhány képet mutatunk az öre- gített papírfelületre és papírlapokra, melyeket – Kutatás és fejlesztés Bauer McNett frakcionátoron frakcionált rostok- – Vizsgálatok, szakértői mérések ból állítottunk elő.
– Műszaki és tudományos információs szol- A rost-víz kölcsönhatást – Statisztikai és piaci információs szolgál- – Klemm szerinti vízfelvétellel – Elméleti és gyakorlati oktatás, részvétel – Vízbe történő bemerítés utáni vízfelvétellel főiskolai és egyetemi képzésben – A papír felületére ejtett víz felszívódásával – Szabványosítással kapcsolatos munkák- – PDA készülékkel mért, rövid ideig tartó ban való részvétel in the field of fine structure
of cellulose fibres in PRI
Alex Hernádi and Istvan Lele Paper Research Indrustry, Budapest H-1215 Budapest, Duna u. 57.
Tel: (36-1)-277-37-50, Fax: (36-1)-276-59-21 Results and discussion
History of the Hungarian pulp and paper Foundation of the research institute: 1949, One method for measurement of porosity of its transformation into private company: 1991.
fibres and paper sheets is the mercury porosim- Based on its almost 60 years experience the etry. The clue of this method is that the mercury Hungarian Paper Research Institute offers its does not wet fibres and under pressure fills their services for companies and institutions, oper- ating in the pulp and paper, paper converting, packaging, printing and related industries, as p = –2γ·cosθ/r
well as in trade and education.
there γ – surface tension of mercury,
We offer the following services: θ – contact angle of mercury on the – research and development in the area of pulp and paper production, paper and board Pore volume and pore size distribution can converting, gluing, printing, environmental
be calculated from capillary resistance and protection, collection and service of market, outer pressure.
trade, production and technical data. A Carlo Erba mercury porosimeter meas- – tests, certifying measurements ures the total pore volume in the range 0,1 – 100 – service of technical and scientific information cm3/g. The applied pressure during measure- – service of statistical and market information ment changes between 104 – 108 Pa.
– theoretical and practical training, voca- tional education Average pore radii of different fibres are – contribution to the formation and introduc- given in Table 1.
tion of standarts • The pore structure of paper [1]Paper itself contains a cluster of voids of different types and origin. The void system is incorporated in and amongst the components The structure of fibres was investigated by of solid network. Different methods can be used to investigate the effect of raw materials, – Mercury porosimetry rate of delignification, mechanical treatment – Scanning electron microscopy (beating and pressing) on the pore volume – Studying fibre- water interaction using dif- and pore radii. It was established that the cel- lulose fibre has at least three different pore system depending on the form of existence Averge pore radii, µm
– submicropores, which exist only in swollen Black pine
state between lamellas of microfibrilles, – micropores, which are in the fibre wall and in the lumen and in pitch hole etc., Bleached chemical – macropores which are the interfibre voids existing only in paper sheet and disap- pearing in pulp slurry condition SCANNING ELECTRON MICROSCOPY
Bleached chemical Scanning electron microscopy (SEM) was used to investigate the surface of cellulose – different treatments, Bleached chemical – fractionating of fibres.
Some pictures can be seen on the next Table 1. Pore radii paper from 1797 paper from 1609 Fig. 1.: SEM pictures of ancient papers Fig. 2.: SEM picture of different fractions of OCC fibres Fig. 3.: Water take-up of enzimatically treated aged paper Fig. 5.: Some curves of short time wetting on different paper PRI as an industrial applied research institu- tion uses special methods of research for the solution of industrial problems – Beside this PRI also takes role in aca- demic research and in the education – Staff of the institute is involved into the education of students and PhD students – Scientists of the institute participate on national and international conferences and symposia Fig. 4.: Measuring principle of PDA device STUDYING FIBRE-WATER INTERACTION BY
[1] Hernádi S.: A papírban levő pórusok szerkezete, azok mérete és meghatáro- – water take up by Klemm Fig. 3.
zásának módja (Structure of the pores – water take up after immersion into water – suction of water dropped onto the paper Papíripar 47 (1) 11-15 (2003) – short time wetting of paper measured by [2] Hernádi S. – Lele I. – Rab A.: Különböző PDA device (Fig. 4)
szekunderrostok iniciál nedvesedése és lapképző tulajdonságai közötti össze- Results of short time wetting of paper meas- függések vizsgálata (Initial wetting of ured by PDA device are shown in Fig. 5. [2]
different secondary fibres) Papíripar 47 (4) 126-130 (2003) MEGHÍVOTT ELŐADÓK és a módszer használata fa, farost, szálasanyagok
és ezek származékainak vizsgálatára
Alumna – Johannes Kepler Universität Linz, Austria A pirolízis gázkroma- zonyítottuk, hogy a pirolízis körülményei között a ligninből tipikusan keletkező benzaldehidek a metria (Py-GC/MS) egy jelenlévő TMAH hatására Cannizzaro reakcióban gyors és rendkívül haté- vesznek részt, ahol az ekvimolárisan keletkező sav kony módszer komplex és alkohol párosból a benzoesavak rögtön teljes szerkezetű szintetikus, s mértékben metileződnek észterekké, az alkoholok főleg természetes poli- pedig kémiai szerkezetüktől függően csak részben merek analízisére, vala- alakulnak át metil-éterré.
mint többkomponensű A cellulóz és hemicellulózok hagyományos összetett rendszerek, pirolízise rendkívül sok terméket eredményez, ami mint pl. a papír is, vizsgá- „fingerprint" (ujjlenyomat) jellemzésre nemigen alkal- latára. A termikus vagy a mas. A TMAH-ot Fabbri alkalmazta először mono-, Tánczos Ildikó reaktív pirolízis termékeit di- és poliszacharidok pirolízisében. A hagyomá- nyos pirolízistől eltérő és kevesebb terméket kapott, gével választjuk szét, s tömegspektrumuk alapján közöttük a cukrok lúgos reakcióira jellemző szacha- azonosítjuk. A bomlástermékek analíziséből indirekt rinsavak metilezett származékait. Mi uronsav THM módon kapunk információt az eredeti mintáról.
analízisének alkalikus bomlásra jellemző származé- Erősen poláris anyagok pirolízisekor gyak- kát találtuk és azonosítottuk a pirogramban.
ran a keletkező termékek is erősen polárosak, Az analitikában, különösen a lignin hidrolízisé- melyek nehezen jutnak át a pirolizátorból a ben jól bevált TMAH-t technológiai folyamatokban gázkromatográfra, s direkt kromatográfiás analízi- is kipróbáltuk. A fafeltárásban a nátrium-hidroxid sük is igen problematikus. Mellékreakcióként pedig helyett alkalmazva, ugyanolyan moláris koncentrá- dekarboxileződés fordulhat elő.
ció és hőfok mellett, jelentősen alacsonyabb kappa Ezen hátrányok kiküszöbölésére vezette be szám és könnyebb fehéríthetőség volt elérhető Challinor a 90-es években a tetrametil-ammó- a cellulóz minőségének és hozamának csökke- niumhidroxid (TMAH), mint reaktív ágens hasz- nése nélkül. Kraft feltárásban TMAH megfelelő nálatát a pirolízisben. A TMAH segíti a nagy arányú alkalmazása NaOH helyett lehetővé teszi molekulájú anyagok lúgos hidrolízisét és közepes a szulfiditás csökkentését, miközben a kitermelés metilező hatása révén segíti a bomlástermékek akár nőhet is. Lo-solids® folyamatokban rögtön az kromatográfiás analízisét. A módszer leginkább első, az impregnációs fázisban alkalmazva mutat- elterjedt megnevezése: termikusan segített hidrolí- kozik meg előnyös hatása. A TMAH cellulózra gya- zis és metilezés – rövidítve THM.
korolt hatásának vizsgálata során megállapítottuk, Mi a linzi egyetemen vizsgáltuk a TMAH ana- hogy 2 mol/l koncentráció fölött jóval erősebben litikai és technológiai alkalmazásának bizonyos duzzasztja a cellulózt, mint a NaOH, ugyanakkor a cellulóz késlelteti a TMAH termikus bomlását.
Az analitikai alkalmazásban tanulmányoz- A Py-GC/MS technika rendkívül egyszerű tuk különböző fa-, lignin és cellulózminta, vala- módszernek mutatkozott fa- és cellulózszárma- mint számos modellvegyület reaktív pirolízisét. zékok analízisére. Újonnan kidolgozott eljárás- Magyarázatot találtunk a fa- és ligninminták THM sal, izopropenil-acetát segítségével acetilezett pirogramjaiban korábban megfigyelt intenzív ben- vagy acilezett származékok acilezési fokának, a zoesav-metilészter származékok megjelenésére. szubsztituensek arányának mintaelőkészítés nél- Modellvegyületekkel végzett kísérletekkel bebi- küli gyors meghatározását teszi lehetővé.
Pyrolysis-Gas Chromatography-Mass Spectroscopy
and its use for the analysis of wood, pulp, fibers
and their derivatives
Alumna – Johannes Kepler University Linz, Austria tion of complex structures, both synthetic and natural polymers even in different composites (for The Pyrolysis Gas-Chromatography Mass- example wood, wood composites, fibres, paper Spectrometry is a very quick and high-power with additives, etc.). method for the analysis of complex structure of Very small amount of samples are needed wood, fibres and papers. The use of tetramethyl- and in a very short time characteristic fingerprints ammonium hydroxide (TMAH) in the pyrolysis sig- can be obtained from the samples without being nificantly increases the efficiency of the method. isolated their components.
The thermally assisted hydrolysis and methylation However, pyrolytic analysis of highly polar sam- (THM) was applied in the analysis of different ples may lead to incorrect conclusions if highly polar wood and lignin samples as well as for lignin model products are evolved which are difficult to transfer compounds. The origin of benzene carboxylic acid from the pyrolizer to the GC and are almost impos- methyl esters in the pyrograms of lignin and wood sible to chromatograph. Furthermore, as unwanted was declared. On the field of carbohydrates the thermal reaction decarboxylation may occur. pyrolysis of uronic acid was emphasized. TMAH, the chemical agent of the reactive pyrolysis, was At the beginning of the nineties John Challinor applied also in technical processes as pulping of [2] suggested the usage of tetramethylammonium
wood and swelling of cellulose. The Py-GC/MS hydroxide (TMAH) as reactive agent in the pyroly- proved to be very useful in the analysis of vari- sis to avoid the above mentioned limitations. The ously acylated wood samples, too.
TMAH is a strong base and a moderate methylat-
ing agent (Fig. 1).
The naming of the reactive pyrolysis method is not uniform. It is referred in the literature as: In spite of the great development in the analyt- ical equipments, the analysis of natural materials • Pyrolysis in the presence of tetramethyl- as wood and fibres is difficult due to their complex ammonium hydroxide structure and the high molecular weight of the • Pyrolysis-methylation GC/MS components. Instead of a direct analysis, the analysis of their pyrolytic decomposition products provides an alternative possibility. The products evolving at the pyrolysis will be separated by gas chromatograph and analyzed
by mass spectrometry (Py-GC/MS). The original
structure will be concluded from the decomposi-
tion products. The modern multifunctional pyrolysis
systems enable evolved gas analysis, flash pyroly-
sis, reactive pyrolysis, thermal desorption and
double-shot analysis [1].
The Py-GC/MS is a quick and high-power method especially for the chemical characteriza- Fig.1. Tetramethylammonium hydroxide • Thermochemolysis many years the origin of these α-carboxylic acids • TMAH thermochemolysis and was not clear.
• Thermal Hydrolysis and Methylation (THM) Martin and his co-workers [4] ascribed the
presence of the benzene carboxylic acid methyl Advantages of the THM analysis: esters first of all to the technique since it avoids the decarboxylation, on the other hand to oxida- – Alkaline media helps the hydrolysis of poly- tion of some structural components of lignin.
Hatcher and his colleges [5] supposed that
– Fewer decomposition products – but differ- TMAH assists in the production of these acids but ent from the conventional pyrolysis they did not find a possible reaction mechanism to – The product yields are higher explain the presence of them.
– Lower temperature is enabled due to the chemical hydrolysis We succeeded to prove and demonstrate [7,8]
– Pyrolytic decarboxylation may be avoided that benzene carboxylic methyl esters can be pro- – The evolved free carboxylic acids will be duced from benzaldehydes that are typical side chain cleaved products in lignin pyrolysis. Benzal- – Organic alcohols may be also methylated dehydes evolved in the pyrolysis (as aldehydes hav- – The methylated products are in most cases ing no α-hydrogen) in the presence of TMAH can better to characterize and give sharper GC undergo to a Cannizzaro reaction producing in equi- signals due to their increased volatility molar amounts the corresponding benzylic alcohols and benzene carboxylic acids – that is immediately The method is sensitive to the parameters of the a salt of the acid. Under the circumstances of the analysis: temperature, TMAH/sample ratio, solvent pyrolysis there is a second step in the reaction, the of TMAH (methanol or water), sample preparation methylation of the evolved products (Fig. 2).
(incubation time of TMAH/sample mixture, etc.).
In the lignin pyrograms – also from different researchers - beside a given benzaldehyde the Analytical use of TMAH in reactive pyrolysis
corresponding products of the Cannizzaro reac-tion can be really observed. To determine the THM analysis of wood importance of this reaction during the pyrolysis three factors must be considered: All components of wood have been already 1. the yield of the Cannizzaro type reaction of the evolved aldehydes 1. most studied is the THM analysis of lignin and the easiest to identify the decomposi-
tion products [3,4,5]
analysis of the cellulose and hemicellu-
loses: the decomposition pattern is more
complicated and difficult to identify the
decomposition products. Sensitive to the
sample preparation [6].
3. Less work has been done with the extrac- THM analysis of lignin In contrast to the conventional pyrolysis the THM analysis of wood or lignin resulted always in relatively high amount benzene carboxylic acid methyl esters. They were absent in conventional pyrolysis. Mono-, di- and trimethoxybenzenecar- Fig. 2.: Cannizzaro reaction of benzaldehydes evolved in the boxylic acid methyl esters were detected. For pyrolysis of lignin 2. the yield of the methylation by TMAH two significant new peaks [9]. Applying the gener-
3. detectability of all compounds in the Py-GC/ ally accepted reaction mechanism of the effect of strong bases on reducing sugars to glucuronic acid we assigned the new peaks as epimers of the cor- Investigations with different aldehydes com- responding permethylated deoxy glucaric acids.
mon in the lignin pyrolysis showed that the dis-proportionation is strongly effected by the sub-stituents and the position of substituents in the Technical use of TMAH in delignification
aromatic ring, for example OH-group in the p- and swelling
position has a blocking effect – as in the case of
vanillin [7].
Delignification of wood using TMAH instead of NaOH – Quatam process THM analysis of cellulose and hemicelluloses At the analysis of wood or pulp, the decompo- The pyrolytic analysis of cellulose and hemi- sition products of lignin are dominant in the THM celluloses is more complicated. Fabbri [6] was
pyrogram. We thought TMAH had to be a very the first who explored the behaviour of various good agent in the alkaline hydrolysis of lignin. monosaccharides combined with 1,4-linked car- So we tried it as a reactive agent in wood pulp- bohydrates. As characteristic products of mon- ing instead of sodium hydroxide: in Soda, Sulfite, osaccharides, such as xylose, glucose, mannose, Kraft and Lo-solids® processes. arabinose, C5 and C6 meta-saccharinic acid The experiments in laboratory and later in semi- methyl esters were identified under the products. pilot plants confirmed our assumption [10,11,12] The
In contrary to the monosaccharides, iso-sac- tetramethylammonium hydroxide showed a signifi- charinic acid methyl ester isomers were detected cantly better pulping effect than the commonly used as primary products of the glycosidically linked sodium hydroxide both in hardwood and softwood pulping under the same circumstances. In Kraft The glucuronic acid groups are important con- pulping the sulfidity could be drastically reduced stituents of the xylan backbones of hemicelluloses. without a decrease in the pulp quality. In Lo-solids® We studied the thermochemolysis of uronic acid, process the highest efficiency could be achieved if too (Fig. 3). In the pyrogram we could observe
TMAH was used in the impregnation stage. 1: 2,4-dimethoxybutanoic acid methyl ester2/3: C5 methylated metasaccharinic acid methyl 4:* unknown 5/6: we assigned as tri-O-methylated-3-deoxy- glucaric acid dimethyl esters Fig.3.: THM pyrogram of glucuronic acid compared to the those of xylose and xylobiose [9]
Fig. 4.: Kappa numbers of pulps obtained in Soda and Quatam process under the same circumstances. Where may be the differences between the decay of TMAH. The temperature range of the effect of NaOH and TMAH? Both physical and decomposition is shifted from134°C to about chemical factors must be considered as size of the cation, hydration, solvation, penetration, adsorption, desorption as well as degradation reactions of lignin and hemicelluloses, second- Py-GC/MS analysis of acylated wood
ary/condensation reactions and methylating effect
of TMAH [11].
The acetylation of wood using isopropenyl acetate (IPA) is a new technique, developed in Using different quaternary ammonium hydrox- the Universität Linz [15]. The acylation process
ides it is obvious that the pulping effect is decreas- was extended also for products containing higher ing with increasing molecular weight (increasing carboxylic acid rests [16] (Fig. 5).
alkyl chains in the molecule) in the sequence Py-GC/MS is a high-performance method for TMAH > tetraethylammonium hydroxide > benzyl- the analysis of wood derivatives, especially in our trimethylammonium hydroxide [13].
case for the analysis of acylated wood containing different carboxylic groups. Not only the grade of Swelling of cellulose TMAH proved to be a more effective swell- ing agent of cellulose than NaOH. The differ-
ence between their swelling effects starts to be
significant at about 2 mol/l concentration [14].
This result was assigned to the large size and
non-polar part of TMAH able to penetrate into the
non-polar sheets of cellulose, furthermore, to the
abnormally high activity coefficient of TMAH in
aqueous solution (Fig. 4).
The decomposition pattern of TMAH itself is also changed. TMAH bounded on the cotton fabric contains hardly crystal water anymore and the cellulose stabilizes TMAH. The molecu-lar interaction between TMAH and cellulose results in formation of cellulose-tetramethylam-monium: CellO- [N(CH ) ]+ which retards the Fig. 5. Acylation of wood with IPA+carboxylic acid mixture acylation but immediately the ratio of the different [5] P. G. Hatcher, R .D. Minard, Org. Geo- carboxylic groups in the samples could be quanti- chem. 23 991 (1995) [6] D. Fabbri, R. Helleur, J. Anal. Appl. Pyrol- ysis, 49 277 (1999) [7] I. Tanczos, K. Rendl, H. Schmidt, J. Anal. Appl. Pyrolysis, 49 319 (1999) [8] I. Tanczos, M. Schöflinger, H. Schmidt, J. Many thanks for the collaboration in these Balla, J. Anal. Appl. Pyrolysis 42 21 (1997) works to the graduants and doctoral candidates of [9] I. Tanczos, C. Schwarzinger, H. Schmidt, the Institute for Chemical Technology of Organic J. Balla, J. Anal. Appl. Pyrolysis 68-69, Materials in the JKU Linz, Austria: K. Rendl, M. Schöflinger, A. Pfeiffer, C. Rogl, C. Schwarzinger, [10] I. Tanczos, H. Schmidt, J. Wood Chem. R. Putz, B. Brüstle; to the Wood K plus Austria; and Techn., 22 (4) 219 (2002) to the cooperation partners in the University of [11] I. Tanczos, R. Putz, H. Schmidt, 5th EWLP Technology and Economy, Budapest, Hungary: J. Aveiro, Portugal (1998) Proceedings 581 Borsa, J. Balla, Gy. Pokol.
[12] C. Rogl, I. Tanczos, J. E. Jiang, B. Stromb- erg, K. Henricson, H. Schmidt, 6th EWLP Bordeaux, France (2000) Proceedings [13] A. Pfeifer, I. Tanczos, H. Schmidt, Lenz- [1] The Frontier Multi-Functional Pyrolysis inger Berichte 79 88 (2000) System 2020iD, www.frontier-lab.com/ [14] I. Tanczos, J. Borsa, I. Sajó, K. László, Z. A. Juhász, T. Tóth, Macromolecular Chem- [2] J. M. Challinor, J. Anal. Appl. Pyrolysis, 16 istry and Physics 201 (17) 2550 (2000) 232 (1989) and 18 233 (1991) [15] Verfahren zur Acetylierung des Holzes [3] J. M. Challinor, J. Anal. Appl. Pyrolysis, 61 WO 2004/048417 A1 [16] Verfahren zur Acylierung eines insbeson- [4] F. Martin, J. C. del Rio, F. J. Gonzalez- dere Cellulose und/oder Hemicellulose Vila, T. Verdejo, J. Anal. Appl. Pyrolysis, und/oder Lignin aufweisenden Materials und damit erhältliches Material A 9/2005 1. MUNKACSOPORT – Különböző kezelések hatása a papíripari rostok szerkezetére és kémiai összetételére fehérítetlen és fehérített eukaliptusz kraftcellulóz
rostok felületi rétegeinek elemzése
Arnis Treimanis1 – Antje Potthast2 – Ute Henniges2 – Thomas Rosenau2 Uldis Grinfelds1 – Tatjana Bikova1 – Marite Skute1 1Állami Fakémiai Intézet 27 Dzerbenes Str., Riga LV 1006, Lettország Levelező szerző arnis.treimanis@edi.lv 2Természeti Erőforrások és Alkalmazott Élettudományok Egyeteme Muthgasse 18., A-1190 Bécs, Ausztria Levelező szerző antje.potthast@boku.ac.at A fasejtfal középső va. A (hetero)aromás vegyületek (furanoidok/ lamellájának és elsődle- furángyanták) és oxipoliszacharidok tartalma is ges falának maradvány- sokkal magasabb volt a becslések szerint a felületi frakcióban. Fehérített frakciók esetében a teljes ják a cellulózrost felületi NaOH-os oldhatóság csökkent, és 25 súlyszázalé- rétegének összetételét. kot tett ki a rost felületi rétegei, és 15%-ot a rostfal Várható, hogy ez hat fő része esetében. A felületi komponensek frakci- a cellulózrostok fehé- ókról történő abszorpciójának csökkenése a teljes ríthetőségére is. Jelen spektrális tartományon belül megfigyelhető volt.
munkánk célja az volt, A fluoreszkáló jelölés és GPC-MALLS meg- hogy hidromechanikai mutatták, hogy a felületi réteg frakciójának mole- Prof. Arnis Treimanis kuláris súlyeloszlása lényegesen különbözött a kal szétválasszuk az tömbfázisú rostokétól, leginkább az alacsony eukaliptusz fehérítetlen kraftcellulóz rostjainak molekulasúlyú frakciókban. A belső réteg frak- felületi rétegeit, majd a szétválasztott (lehámozott) ciói megegyeztek a tömbfázisú rost molekuláris rétegeket enzimes fehérítéssel dolgoztuk fel, a súlyeloszlásával. Ugyanez volt igaz a molekula- peroxid – xilanázkezelés – lúgos extrakció – per- súlyra és a karbonilcsoport-tartalomra. A felüle- oxid P1-X-E-P2 sorrendnek megfelelően. Mind a ti rétegekből nyert frakcióra gyakorolt fehérítési fehérítetlen, mind pedig a fehérített rostfalfrakciók hatás nagyon hangsúlyozott volt. Fehérítés után összetételét UV/látható spektroszkópiával és az a molekulasúly csökkent, és a karbonilcsoportok oxidált cellulóz funkciós csoportjainak fluoresz- pedig, ahogy ez várható volt, az összes vizsgált káló jelölésével elemeztük, melyet GBC-MALLS mintában növekedtek. A rostok felületi részét azonban még komolyabban érintette. A felületi Annak érdekében, hogy a maradék lignin és rétegben a karbonilcsoport háromszorosára nőtt, oxipoliszacharidok által előidézett UV-abszorp- összehasonlítva a belső rétegben vagy a tömbfá- cióképesség között különbséget tudjunk tenni, zisú rostban történő kétszeres növekedéssel.
0,5%-os és 10%-os lúgos extrakciót alkalmaztunk A rostfalfrakciók kémiai összetételében vég- NaOH-dal. A teljes NaOH-os oldhatóság fehé- bemenő meglehetősen radikális változások elle- rítetlen felületi rétegekre 40 súlyszázalék volt, nére az elkülönített felületi rétegek ISO-fehérsége a rostfalak fő részére pedig 19%. Az UV spekt- sokkal alacsonyabb maradt a rostok fő részéhez rum megmutatta, hogy a lignin és hexénuronsav viszonyítva. Ez 50%-os ISO-fehérséget jelentett tartalom 3-4-szer magasabb a rostok felüle- a rostok fő részeinek 67%-os ISO-fehérségéhez ti rétegeiben az átlagértékekkel összehasonlít- WORKING GROUP 1. – Structure and chemical composition of papermaking fibres after different types of treatment Analysis of surface
layers of mechanically peeled unbleached and
bleached eucalyptus kraft pulp fibres
Arnis Treimanis1 – Antje Potthast2 – Ute Henniges2 – Thomas Rosenau2 Uldis Grinfelds1 – Tatjana Bikova1 – Marite Skute1 1State Institute of Wood Chemistry 27 Dzerbenes str., Riga LV 1006, Latvia corresponding author arnis.treimanis@edi.lv 2University of Natural Resources and Applied Life Sciences Muthgasse 18., A-1190 Vienna, Austria corresponding author antje.potthast@boku.ac.at from the surface layers was very pronounced. After bleaching molecular weight and carboxyl The objective of the present work was group content are decreased in all analyzed to separate the surface layers of eucalyptus samples. Again, the surface-layer fraction unbleached kraft pulp fibres by hydromechani- exhibits a different behaviour than bulk sample cal peeling techniques and to proceed with and inner-layer fractions.
enzyme-aided bleaching of the separated lay- In spite of the rather exhaustive changes in ers according to the sequence peroxide – xyla- the chemical composition during the fibre wall nase treatment – alkaline extraction – peroxide fractions, the ISO brightness of the isolated sur- P -X-E-P . The composition of both unbleached face layers remained much lower as compared and bleached fibre wall fractions was analysed to the main part of fibres. It provided 50% ISO by UV/Vis spectroscopy and fluorescence label- as compared to the 67% ISO brightness for ling of oxidized cellulose functionalities followed main part of fibres.
by GPC-MALLS.
UV spectra revealed the content of lignin and hexenuronic acids to be 3-4 times high- er in fibre surface layers as compared to the average values. The content of heteroaromatic It is established by several researchers compounds (furanoids / furan resins) and oxy- that the residual constituents of middle lamella polysaccharides was also estimated to be much and primary wall of wood cell walls affect the higher in the surface fraction. For the bleached composition of pulp fibre surface layers. It fractions the decrease of the absorbance of the is expected that this translates into the pulp components from surface fractions occurred fibres' bleachability. In order to perform blea- over the whole spectral range.
ching trials directly with separated fibre sur- Fluorescence labelling and GPC-MALLS face layers (P and S ) and the main part of showed that the molecular weight distribution of the secondary wall (S and S ) as well as with the surface-layer fraction differed significantly intact pulp fibres, hydromechanical peeling of from that of the bulk fibre, mostly in the low eucalyptus unbleached kraft pulp fibres was molecular weight fraction. The inner-layer frac- accomplished. Unbleached fibres (the sample tions equaled the molecular weight distribution for integrated analysis by participants of the of the bulk fibre. The same held true for molecu- COST Action E41) were acquired from the lar weight and carbonyl group content. The industrial digester before oxygen delignifica- impact of bleaching on the fraction obtained WORKING GROUP 1.
Materials and methods
total NaOH solubility was 40% by weight for unbleached surface layers and 19% for the The hydromechanical peeling techniques residual part of the fibre wall. Fluorescence was applied to separate the surface layers of labelling of oxidized cellulose functionalities fol- eucalyptus unbleached kraft pulp fibres [1].
lowed by GPC-MALLS was performed accord- The peeling of the surface material was moni- ing to [2],[3].
tored by „Lorentzen&Wettre Fiber Tester" and digital microscope „Leica DM5500", separa-tion of the fractions was done by wet fibres Results and discussion
shaker „Retzsch AS200" following by centrifu-gation and freeze-drying. The peeling process In order to elucidate the distinctions in the was interrupted before the fragmentation of the chemical composition of the fractions before the fibres had started. The degree of the exposure bleaching, the UV-spectra (Fig. 1) and the 1st
of the secondary wall S layer usually reaches derivative of the spectra were analysed. When 30-50% as a consequence of the suspension 0.5% NaOH solution is applied, the absorbance of the procedure. Separated fibre wall frac- values at 218, 290, 330, 350, 386 and 390 nm tions, i.e., rather clean surface layers (P+S ) are attributed to lignin. Strong absorbance of and conditionally the main part of secondary the alkaline extract from fibre surface layers layer (S +S ), were analysed by standard TAPPI at 245 nm and weaker UV-absorbance at 244, methods and subjected to the enzyme-aided 254, 266 and 276 nm for the alkaline extract of bleaching of the isolated layers according to the fraction enriched in S and S layers indicate the sequence peroxide – xylanase treatment the presence of the heteroaromatic compounds – alkaline extraction – peroxide P -X-E-P . The of the furanoid (pyranoid) type. In 10% NaOH composition of both unbleached and bleached extracts, the absorbance at 235 is attributed fibre wall fractions was analysed by UV/Vis to hexenuronic acids (HexA). From UV spec- spectroscopy. In order to differentiate the UV- tra analysis we conclude that the content of absorbance derived by residual lignin and oxy- lignin and hexenuronic acids is 3-4 times hig- polysaccharides, sequential alkaline extraction her in fibre surface layers as compared to the with 0.5% and 10% NaOH was applied. The average values. The content of heteroaromatic Fig. 1. The UV-spectra of the alkaline extracts from unbleached P-S (upper curves) and S -S fractions (lower curves)
(A – 0.5% NaOH; B – 10.0% NaOH). WORKING GROUP 1. compounds (furanoids / furan resins) and oxy- main part of the fiber walls, the S -S layers, polysaccharides is also estimated to be much has lost most of the easily accessible fraction higher in the surface fraction. of hemicelluloses and HexA during the bleach- For the bleached fractions the total NaOH ing procedure. It is indicated by the decrease solubility decreased and was 25% by weight for of the absorbance around 235 nm. At the same the fibre surface layers and 15% for the main time an increase of the absorbance at 235 nm part of fibre wall. The decrease of the absor- in the case of the polyoses from S -S layers bance of the components from surface fractions soluble in strong alkali points to some increase occurred over the whole spectral range. The of HexA at the bleaching conditions used (no absorbance drop at 218 nm and 250 nm by acidic stage).
45% and 63%, respectively, in the 10% NaOH The brightness values of the eucalyptus extract of the surface P-S layers indicates the kraft pulp separated surface (P-S ) and main destruction of the heteroaromatic compounds secondary wall layers as well as whole fibres possibly incorporated in the furan resins. The after bleaching were measured [Fig. 2]. In spite
decrease of absorbance at 280-300 nm and of the rather exhaustive changes in the chemical around 340-360 nm indicates the elimination composition during the fibre wall layers bleach- of both carbonyl groups and double bond con- ing, the ISO brightness of the fibre surface jugated structures in the surface layers. The layers remains much lower as compared to the S -S layers. It makes up 50% ISO as compared to the 67% ISO brightness for both secondary wall layers and whole fibres. The molecular weight distribution of the P-S layer shows a distinct and well separated hemi-
cellulose peak (Fig. 3 left). In the unbleached
samples the amount of carboxyl groups, which
corresponds predominantly to the uronic acid
moeities in the xylan of the eucalyptus pulp
used is comparable in the whole sample and
the S -S layer (Fig. 3 right). Interestingly, the
free uronic acid content in the surface layer is Fig. 2. Brightness values for eucalyptus kraft pulp fibrer and significantly lower compared to the S -S layer. separated fibre wall layers. A possible explanation is the engagement of the Fig. 3. Molecular weight distribution of bleached (left) and unbleached (right) pulps In addition, the figure on the right shows the distribution of carboxyl groups in relation to the molecular weight. WORKING GROUP 1.
Whole pulp
P-S layer
S -S layer
*Determination of carbonyl values in bleached samples was not possible due to fluorescence quenching of lignin. Table. 1: Amounts of carboxyl and carbonyl groups in unbleached and bleached samples uronic acid group in lignin-carbohydrate com- plexes, which corresponds well to the increased
UV activity within the surface layer (cf. Fig.1). In
[1.] Treimanis A.: Advanced traditional meth- the mild labeling protocol the ester linkages are ods of analysis of fibre surface layers – a not cleaved and only free uronic acid groups powerful tool in research of lignocellu- are labeled. The bleached samples showed a losics. La Chimica e l'Industria 88 (2) significantly higher carbonyl group content in 72-75 (2006).
the surface layers than in the bulk sample and in the S -S layer, also indicating the presence [2.] Bohrn, R., Potthast, A., Schiehser, S., of a more complex chemical structure.
Rosenau, T., Sixta, H., Kosma, P. : The FDAM method: Determination of car-boxyl profiles in cellulosic materials by combining group-selective fluorescence labeling with GPC. Biomacromolecules, • Composition of the papermaking (pulp) 7 1743-1750 (2006).
fibres surface layers differs from that of the secondary wall.
[3.] Röhrling, J.; Potthast, A.; Rosenau, T.; • In spite of rather exhaustive changes during Lange, T.; Borgards, A.; Sixta, H., Kosma, bleaching, ISO brightness of the isolated P.: A novel method for the determination surface layers remained much lower. of carbonyl groups in cellulosics by fluo- • Carboxyl groups in surface layers are rescence labeling. Part 2: Validation and engaged in lignin-carbohydrate com- Biomacromolecules 3 969-975 (2002).
Technical Association of Paper and Printing Industry – Budapest pnyme@mtesz.hu – www.pnyme.hu Újonnan kifejlesztett módszer
az egyedi rost rugalmasságának méréséhez
R. Eckhart1 – M. Donoser2 – W. Bauer1 1Papír, Cellulóz- és Rosttechnológiai Intézet – IPZ Grazi Műszaki Egyetem Kopernikusgasse 24/II A-8010 Graz, Ausztria 2Számítógépes Grafikai-és Vizualizációs Intézet-ICG Grazi Műszaki Egyetem Új módszer került Az áramlási mezőt az Áramlástani és Hőát- kifejlesztésre az egye- adási Intézetben szimulálták folyékony anyag di rost rugalmasságá- (FLUENT) alkalmazásával. A sebességkompo- nensek x és y irányban, valamint gradienseik 30 nek meghatározására m-es térbeli felbontással ismertek.
szuszpenzióban. A Erre a szimulációra alapozva elérhetők azok vízben szuszpendált a hidrodinamikus feltételek, melyeknek a rostok rostokat egy plexiből az áramlási mezőben ki vannak téve. A rost rugal- készült átlátszó áram- massági modulusban kifejezett rugalmasságának lási cellában nyíróerők- kiszámításához a folyadékáram miatt a rostra nek tették ki. A rostok ható valódi erők szükségesek. Ezeket az erőket Rene Eckhart a rost és a folyadék közötti sebességkülönbség léséhez transzmisszi- határozza meg. Ez a sebességkülönbség nem ós fénymikroszkópon alapuló nagysebességű számítható ki egyszerűen, mivel a folyadékáram- képelemzési rendszert használtak. A maxi- lási feltételek, amelyek között a rostot használják, málisan elkészített képek száma 500 kép volt drámai módon változhatnak két egymást követő másodpercenként. Az optikai felbontás 7,63 [µm/pixel]. Képelemzés alapján egy-egy rost A rostrugalmasság/merevség meghatározá- képe maximum ötször vehető fel a nagy nyíró- sának általunk követett koncepciója a rost és erejű zónában. egy ideálisan rugalmas partner összehasonlítá- Az egyedi rostnak a hidrodinamikus terhe- sán alapszik. Az egyedi rost áramlási mezőben lésre mutatott reakciója lesz az adott rost rugal- való reprezentálása alapján kiszámítjuk ennek a massága meghatározásának az alapja. rostnak a helyzetét és megjelenését a következő Az áramlási cellát az Áramlástani és Hőát- képen, feltéve, hogy a rostok középvonalában adási Intézettel együttműködésben fejlesztet- lévő minden egyes pont ideális módon követi az ték ki a Grazi Műszaki Egyetemen. áramlási mezőt. Ennek az ideálisan rugalmas Az eredmény egy olyan cella, amelyben rostnak a referenciarosttal összehasonlított vál- azonos áramlási sebességgel rendelkező két tozását értékeljük az alak összehasonlításával. áramot egymással szemben vezetnek. Ezál- Az alak hasonlóságát a rost alakját leíró, több tal elegendő nyíróerő keletkezik ahhoz, hogy paramétert tartalmazó vektorok közti euklideszi látható rostdeformáció keletkezzen lamináris távolság alkalmazásával számítjuk ki.
áramlási rendszer feltételei mellett.
A valós rost deformációját hasonló módon A pulzálás elkerülése érdekében (a pul- értékeltük (a referenciarostot hasonlítottuk zálások befolyásolnák vagy akár rombolnák valódi reprezentációjához a következő képen). is a lamináris áramlási mezőt) a szuszpenziót A valós rost deformációja és az ideálisan rugal- sűrített levegő alkalmazásával a transzparens mas rost deformációja közti arányt alkalmaztuk cellán keresztül átszivattyúzzák.
WORKING GROUP 1. A Newly Developed Method for Single Fibre
R. Eckhart1 – M. Donoser2 – W. Bauer1 1Institute for Paper, Pulp and Fiber Technology – IPZ Graz University of Technology Kopernikusgasse 24/II A-8010 Graz Austria 2 Institute for Computer Graphics and Vision – ICG Graz University of Technology the fibre to fibre contact in a sheet [2]. Still, neither
of these methods can be applied on line.
A new method for single fibre flexibility meas- Today pulp morphology parameters like for urement in suspension was developed at the Insti- example fibre length, width, curl or kink [3] are to an
tute for Pulp, Paper and Fibre Technology at Graz increasing extent determined using commercially University of Technology.
available flow cells with high on line applicability. A flow cell with suitable channel geometry is Highly diluted fiber suspension is pumped through used to induce a flow field with high shear forces a transparent cell and photographs of individual in flowing suspension. These shear forces are fibers are taken by means of transmitted light micro- strong enough to deform pulp fibres under laminar scopy. Automated image analysis is used to detect flow conditions. A high speed image acquisition and evaluate the fibres in these images. system is used to acquire several images of a fibre Two fibre flexibility measurement methods while passing the transparent flow cell. Thereby show at least theoretical on-line applicability in the deformation of the fibre due to the shear forces such a flow cell. Kuhn et.al. [4] described a meth-
od where fibres are photographed while exiting To gain access to the defined flow conditions a capillary tube into a main channel. The fibres at any point in the sheared region the flow field are deformed due to the load of the fluid flow of was simulated in FLUENT. the main channel. The deformation of the fibres The fluid flow is then linked with the fibres exiting the tube is compared to that of fibres of reactions. Thereby a flexibility parameter for every defined flexibility, simulated under the same flow evaluated fibre is determined.
conditions. This method was never implemented in a commercially available device.
Another method was patented by STFI in 1992 [5]. The fiber curl of a large number of fibers is
registered at two different flow velocities. As the
Fibre flexibility/conformability is an important shear rate in the flow cell is higher at increased pulp parameter during stock preparation, sheet fluid velocity the fibers are straightened in the forming, in fiber to fiber bonding and thus for the second run. Fibre flexibility is not determined for resulting paper properties.
every single fibre but defined as the relationship Several fibre flexibility measurement methods between the average fibre curl values of the two are mentioned in the literature. Some are based on measurements. The method is implemented in the single fibre manipulation and apply bending beam commercial fiber analyzer FibreMaster.
theory to determine a modulus of elasticity. These The goal was to develop a flow cell based meth- methods are rather tedious and or can not treat all od that delivers flexibility values for every evaluated fibres in a given pulp sample but are restricted to fibre. That way not only average flexibility values but rather long and undamaged fibres [1]. Others are
distributions of fibre flexibility should be accessible. based on the fibres ability to conform to a wire/ Such distributions of fibre flexibility might deliver glass fibre/another pulp fibre after settling on to a beneficial information concerning for example the glass slide. These methods determine a "conforma- earlywood-latewood ratio or the number of fibres bility" that is closer to the fibre property relevant for reached during a refining process.
WORKING GROUP 1. that the fibres tend to move in the centre plane of the flow channel. Furthermore the z-direction of the The idea is to use an appropriate flow cell channel is not accessible in the images. Therefore geometry to generate shear forces strong enough only the centre plane of the channel was simulated. to provoke fibre deformation under the boundary The velocity components in x- and y-direction as well condition of a laminar flow regime. A high speed as their gradients are known with a spatial resolution image acquisition system is used to record the of 30 μm. As an example Fig. 1b shows a contour plot movement of single fibers in the sheared region. representing the velocity magnitude in the flow cell.
Based on the fibres deformation due to the fluid Based on this simulation, the hydrodynamic forces a flexibility parameter is determinable for conditions in the flow field are accessible and can every evaluated fibre.
be linked to the fibres reactions.
Images are acquired using a Basler A504k high speed camera. It allows a frame rate of 500 images The Flow Cell
per second. Thereby each fibre passing the cell is acquired 2 to 3 times in the region of highest shear The flow cell was developed in cooperation with forces. The optical resolution is 7.63 [µm/Pixel]. Illu- the Institute of Fluid Mechanics and Heat Transfer of mination is done using one red high power LED.
Graz University of Technology (Fig. 1.) .
Automated image analysis is used to evaluate Several channel geometries were tested but only the acquired images. Two main tasks have to be the one described in the following induced shear forc- accomplished by the image analytical algorithms: es strong enough to provoke visible fibre deforma- fibre segmentation and fibre tracking through the tion under the boundary condition of a laminar flow consecutive images, where fibre tracking means regime. Two fluid streams of identical flow rate and relocating a specific fibre in the consecutive image.
velocity are headed against each other in a crossing. The segmentation process starts with a back- The average flow velocity in the ingoing channels is ground correction to delete impurities in the optical 1,4 [m/s]. No turbulence or mixing of the fluid streams path and eventual uneven illumination. In the next headed against each other occurs. Fig. 1a shows step binary images of the fibres are calculated. schematically the transparent flow cell made of Plexi Based on these binary images the corners of the Glass. To avoid pulsations (pulsations would affect fibre are detected and the fibre is reduced to its or destroy the laminar flow field) in the fluid flow, centreline. Fibre length as well as the centre of suspension transport is done using a pressure resist- gravity is calculated. ant glass bottle equipped with a stand pipe and a Tracking of the fibres through the consecutive compressed air connection. Thereby the suspension images is done using the flow field data and the is pumped through the flow cell by air pressure.
fibres length. The region where the centre of gravity The flow conditions in the flow field were simu- of a detected fibre should most likely emerge in the lated by the Institute of Fluid Mechanics and Heat following image can be calculated. If a fibre within Transfer using FLUENT. Experiments have shown a certain distance to this calculated region shows Fig. 1: The flow cell made of Plexi glass with the two streams meeting in a crossing and the profile of the velocity field in the region of high shear forces (one of the symmetric quarters) WORKING GROUP 1. an adequate fibre length it is selected as a second undergoes compared to the reference fibre in the representation of the specific fibre. That way up to first image is evaluated using a comparison of five representations of a fibre can be captured for shape. The Euclidian distance between vectors flexibility determination. containing several shape parameters and thereby describing the shape of the reference fibre and of the calculated ideally elastic one represents the Determination of Fiber Flexibility
deformation of the ideally elastic fibre and thereby determines the "load" acting on the fibre.
For a calculation of fibre flexibility in terms of an The deformation of the real fiber in the high shear elasticity modulus the real forces acting on the fibre zone is calculated likewise based on the reference due to the fluid load would be necessary. These fibre (the one that was used to calculate the ideally forces are determined by the speed difference elastic one) and the same fibre in the consecutive between fibre and fluid. In our concept this speed image. The deformation of the real fibre due to the difference is not determinable as the fluid flow con- fluid forces determines the "reaction" of the fibre. ditions a fibre is exerted to can change dramatically The ratio between the deformation of the real between two consecutive images. Even an estima- fiber and the ideal one, the ratio between "reac- tion of the translational and the rotational part of tion" and "load" is used as a parameter for the fiber movement would demand a higher framerate. Therefore an approach using bending beam theory The method delivers promising results e.g. for and the forces acting on the fibre to determine the softwood fibres with different drying history or for modulus of elasticity seemed inappropriate.
fibres treated in a laboratory refiner to increase The concept for the determination of the fibres fibre flexibility step by step.
flexibility/rigidity is based on a comparison of the fibres behaviour with that of a calculated ideally elastic counterpart. Two consecutive images of the same fibre are taken into account for the determination of its The authors gratefully acknowledge financial flexibility. The first image of the specific fibre in the support of the Austrian Research Promotion Agen- region of high shear forces is used to calculate cy Ltd. (FFG) and of Andritz AG, Pöls AG, Sappi position and appearance of the fibre in the follow- Gratkorn, SCA Graphic Laakirchen, Smurfit Net- ing frame, provided that every single point along tingsdorfer Papierfabrik and the Delfort Group.
the fibres centreline follows the flow field ideally. The result is an ideally elastic fibre following the fluid flow without any restrictions (bright gray in Fig. 2). The deformation this ideally elastic fibre
[1] Tam Doo P.A.; Kerekes R.J.; A Method to Measure Wet Fiber Flexibility. Tappi Jour-nal, 64 (3) 513 (1981) [2] Mohlin U.B.; Cellulose fibre bonding; Part 5. Conformability of pulp fibres. Svensk Paperstidning, 78 (11) 412 (1975) [3] Jordan B. G.; Nguyen N. G. Curvature, Kink and Curl. Paperii ja Pu, 4 313 (1986) [4] Kuhn D.C.S.; Huang Z.; Trepanier R.J.; Patchka H.; Dynamic Wet Fiber Flexibil-ity Analyzer. TAPPI Procedings / Process and Product Quality Conference and Trade Fair, page 67 1997.
[5] STFI; Method and Apparatus for Measur- ing Fibre Flexibility. International Patent Fig. 2: Two schematic representations of a fiber as it is Classification: G01N 15/02, International photographed in the high shear zone and the calculated, ideally elastic counterpart (bright grey); scaling in pixels Publication Date: 02. April 1992, Interna- (7,36 µm/pixel) tional Publication Number: WO 92/05423.
Cellulóz szupramolekuláris szerkezetének szilárd
fázisú NMR és Röntgen-diffrakciós összehasonlító
vizsgálata fenyő kraftcellulóz roston
Per Tomas Larsson*, Mihaela Cristina Popescu** és Cornelia Vasile***STFI-Packforsk AB, Box 5604, SE-114 86 Stockholm, Svédország, tomas.larsson@stfi.se ** P.Poni Institute of Macromolecular Chemistry Department of Physical Chemistry of Polymers 41A Grigore Ghica Voda Alley, R0 700487 IASI A COST E54 akció néhány a meglévő modellek keretén belül ösz- keretén belül közös rost- szehasonlítható. A Röntgen-diffrakció és az mintákat használtak. NMR különböző természete miatt különböző Egy fehérítetlen fenyő modelleket alkalmaztak az adatok értelmezé- kraftcellulózt és egy fehé- sére, ami bizonyos mértékig megnehezítette az rített fenyő kaftcellulózt összehasonlítást. Az cellulóz I, lévén félkristá- bocsátottak az összes lyos anyag, amely a rostfal komplex morfológiá- akcióban résztvevő ren- jába rendezett biopolimerekből áll, nem igazán delkezésére. A COST optimális anyag az NMR vagy Röntgen-diffrak- E54 akció keretén belül ciós mérésekhez.
szilárdfázisú NMR (CP/ Az összehasonlítás az eredmények három MAS 13C-NMR) és Rönt- kategóriájára történt: cellulóz I látszólagos Tomas Larsson gen diffrakciós adatok krisztallitmérete, a kristályosság foka és a rost- (XRD) eredményeit rögzítették.
falban lévő cellulóz cellulóztartalma. Ez a három Az azonos anyagokkal végzett vizsgálatok tulajdonság, közvetve vagy közvetlenül, rendel- a műszeres mérések széles körének alkalma- kezésre áll mind a Röntgen-diffrakcióból mind zásával ritka alkalmat teremtenek a módszerek az NMR mérésekből.
interkalibrálásához és az adatok értelmezésé- A Röntgen-diffrakció és NMR működési hez használt modellek érvényességének vizs- elveinek különbözősége miatt az 1. táblázat-
gálatához. Ebből a célból a Röntgen-diffrakció ban bemutatott eredmények közti egyezőség a
és NMR mérések eredményeinek összehason- kiválótól a jóig értékelhető. A cellulóztartalom becslésében megállapított különbség várható Az összehasonlítás fő célja a cellulóz I volt, mivel tudott, hogy az NMR módszer nem szupramolekuláris szerkezete, azaz a cellulóz veszi figyelembe a hemicellulóz jel intenzitá- nativ formája volt. Az NMR és Röntgen-diff- sát. Mindkét módszer enyhe növekedést mutat rakció alapvetően különböző mérési techni- fehérítés után a látszólagos krisztallitméretben, kák, melyek adatokat hoznak létre; ezek közül míg a kristályosság foka változatlan marad.
Látszólagos krisztallitméret (nm) Kristályosság foka (%) Cellulóztartalom (%) 1. táblázat: A cellulózmintákon rögzített Röntgen-diffrakció és NMR eredmények Az NMR esetében a látszólagos krisztallit- méreteket a mért átlagos laterális fibrilla-méretből becsültük, figyelmen kívül hagyva a fibrilla-felületi polimereit. A glükánlánc átlagos laterális mérete 0,57 nm volt. A kristályosodás fokának NMR becslése tartalmazza a parakristályos formákat is. WORKING GROUP 1.
A comparative CP/MAS 13C-NMR and XRD study of
the cellulose supra-molecular structure in softwood
kraft pulp fibers
Per Tomas Larsson*, Carmen Mihaela Popescu** and Cornelia Vasile** *STFI-Packforsk AB, Box 5604, SE-114 86 Stockholm, Sweden, tomas.larsson@stfi.se ** P.Poni Institute of Macromolecular Chemistry Department of Physical, Chemistry of Polymers, 41A Grigore Ghica Voda Alley, R0 700487 IASI Key words: estimates of cellulose allomorph composition, Softwood kraft pulp, spruce, pine, Nuclear degree of crystallinity, lateral dimensions for both Magnetic Resonance, CP/MAS 13C-NMR, XRD, cellulose fibrils and for cellulose fibril aggregates. X-ray diffraction, cellulose supra-molecular struc- In cellulose I isolated from softwoods cellulose I ture, Cellulose fibril, Cellulose fibril aggregate, fibrils are typically 4 to 5 nm thick and cellulose Kraft cooking, Bleaching fibril aggregates thicknesses range from 15 to 30 nm depending on isolation procedure. The most known method of determining the structure characteristics of cellulose substrates is the study of their X-ray diffraction, in the small Cross Polarization Magic Angle Spinning (CP/ as well as wide angle region. The X-ray diffrac- MAS) Carbon-13 Nuclear Magnetic Resonance tion in the wide angle region (beyond 2θ = 6 (13C-NMR) spectroscopy and X-Ray Diffraction degrees) allows the determination of the degree (XRD) has been used to study cellulose I structural of crystallinity, the degree of orientation and from characteristics. Both methods were applied to the the width at the half maximum intensity of the same set of samples, unbleached and bleached meridional and equatorial reflections, the crys- softwood kraft pulps. Despite the differences in tallite length and width dimensions, respectively principles of operation the two measuring tech- (Krässig 1993 [4],Teeaar 1987 [7]).
niques give some estimates of material properties The average size of the crystallites can be that can be compared. In this study the focus was evaluated using the well-known Scherrer equation on the cellulose I fibril dimensions, degree of crys- while the degree of orientation can be obtained tallinity and the cellulose content of the materials. through calculation of the Hermans orientation Within the models used for interpreting the meas- function (Cullity, Stock 2001 [2]). Other charac-
ured data good agreement between the two meth- teristics related to the material crystallinity can be ods were found for fibril dimensions and degree of also obtained (Anderson 2003 [1], Popescu 2007
crystallinity. Estimates of cellulose content were in [6]). Unfortunately this method can not reflect the
qualitative agreement, which was expected since hydrogen bonding patterns, allomorph composi- the NMR method tends to over estimate the cellu- tion in cellulose crystallites and the integrity of the lose content in the presence of hemicellulose.
crystallite (J. Xe 2007).
Both NMR and XRD methods are depen- dent on models for the interpretation of recorded data. Due to the fundamental differences relat-ing to how data is acquired, different conceptual CP/MAS 13C-NMR spectroscopy has been models are used for interpretations. In the case shown to be a versatile tool for the study of cellu- of estimates of lateral dimensions as obtained lose supra-molecular structure (VanderHart 1984 from the two methods it is necessary to impose [8], Larsson 1997 [5], Wickholm 1998 [9], Hult
some assumptions in order to obtain compa- 2001 [3]). Measured spectra can be used to obtain
rable results. Further, the interpretation of NMR WORKING GROUP 1.
spectra includes separate signal intensity from using a 4.3 μs proton 90o pulse, 800 μs ramped so-called para-crystalline cellulose, domains of (100 – 50%) contact pulse and a 2.5s delay highly ordered glucan polymers interior in the between repetitions. A TPPM15 pulse sequence fibril (Larsson 1997 [5], Wickholm 1998 [9]).
was used for 1H decoupling. Glycine was used Currently it is not clear whether or not the para- for Hartman-Hahn matching procedure and crystalline form contribute to the degree of crys- as external standard for the calibration of the tallinity as observed by XRD.
chemical shift scale relative to tetramethylsilane ((CH ) Si). The data point of maximum intensity in glycine carbonyl line was assigned a chemical shift of 176.03 ppm. The software used for spec-tral fitting was implemented at STFI-Packforsk Materials: The unbleached and the bleached AB and is based on a Levenberg-Marquardt pulps were commercial pulps supplied by Södra algorithm (Larsson 1997) [5].
Cell Värö, Sweden. The spruce (P. abies) to pine (P. sylvestris) ratio was 79:21. The pulp was batch cooked and TCF-bleached. The bleaching Results and discussion
sequence was Q OP Q+Paa PO where Q repre-sents a chelator and Paa is per-acetic acid. The The main target for the comparison was kappa-numbers were 26.8 and 3.2 respectively the supra-molecular structure of cellulose I, the for the unbleached and the bleached pulps.
native form of cellulose. NMR and XRD are fun- X-ray diffraction (XRD): The analysis was damentally different measuring techniques that done using a Bruker diffractometer equipped generate data, some of which are directly com- with a Kristalloflex 760 sealed-tube copper parable within the limits of existing models. Due anode generator, operated at 40 kV and 40 to the different nature of XRD and NMR different mA, and a two-dimensional position-sensitive models are used for interpreting data, which to wire-grid detector (Bruker AXS) pressured with some extent complicates the comparison. Cel- xenon gas. Collimation was effected by a graph- lulose I being a semi-crystalline material made ite monochromator with a 0.8-mm pinhole, the up from bio-polymers arranged into a complex sample-to-detector distance was 9 cm. Samples morphology of a fibre wall is not the optimal mate- were placed in sealed Mark-Röhrchen glass rial for NMR or XRD measurements.
capillaries (Charles Supper) of 1.0 mm inner The comparison was made for three catego- diameter (1200 scans). ries of results: cellulose I fibril lateral dimensions, NMR spectroscopy. All samples were wetted the degree of crystallinity and the cellulose con- with deionised water (40 to 60% water content) tent of the fibre sample. These three properties and packed uniformly in a zirconium oxide rotor. are directly or indirectly available from both XRD The CP/MAS 13C-NMR spectra were recorded and NMR measurements.
using a Bruker Avance AQS 300 WB instrument Table 1 shows the results of the compari-
operating at 7.04 T. All measurements were per- son of estimates from NMR and XRD. A slight formed at 290 (+/- 1) K. The MAS rate was 5 kHz. increase in apparent crystallite size due to the A double air-bearing probe was used. Acquisi- bleaching is observed using both NMR and tion was performed with a CP pulse sequence, XRD. Further the agreement in lateral dimension Apparent crystallite size (nm) Degree of crystallinity (%) Cellulose content (%) Table 1. XRD and NMR results recorded on the pulp samples. In the NMR case the apparent crystallite sizes was estimated from the measured average lateral fibril dimension by neglecting fibril surface polymers. The average lateral dimension of a glucan chain was set to 0.57 nm. The NMR estimates of the degree of crystallinity include contributions from para-crystalline cellulose forms. WORKING GROUP 1.
estimates between NMR and XRD is excellent. for financial support. Karin Sjöström, Södra Cell Results obtained from NMR spectral fitting give Värö, Sweden is acknowledged for supplying the estimates for the lateral fibril dimension (LFD) pulp sample materials and pulp specifications. which includes the fibril surface glucan chains. The authors are grateful to Dr. Paul Ander for the The procedure used to translate LFD measures distribution of the sample material to the partici- to apparent crystallite size (the lateral dimension pants within the COST E54 action. of the highly ordered fibril interior) was to remove the contribution of surface glucan from the LFD. This gives a reduction in LFD measures with 1.14 References
nm. These are the NMR values quoted for appar-ent crystallite size in Table 1.
[1] Andersson S. Serimaa R. Paakkari T, Due to the occurrence of para-crystalline Saranpaa P., Pesonen E. Crystallinity of (PC) signal intensity in NMR spectra recorded wood and the size of cellulose crystallites on cellulose I (Larsson 1997 [5], Wickholm 1998
in Norway spruce (Picea abies) J. Wood [9]), a question arises whether or not this form of
Sci., 49 531-537 (2003) cellulose I will be detected as crystalline cellulose [2] Cullity B.D. and Stock S.R. Elements of X- I during XRD measurements. In the studied sam- Ray Diffraction (3rd Edition), 2001. Addi- ples the cellulose I forms classified as crystalline son-Wesley Publishing Company Inc, and para-crystalline were about 20% and 35% Reading, UK.
respectively according to NMR, typical for cel- [3] Hult E.-L, Larsson P.T. and Iversen T. lulose I isolated from softwood. It is obvious from Cellulose fibril aggregation – An inherent the comparison with XRD data that the relevant property of kraft pulps. Polymer 42 3309- basis for comparison consists of the sum of crys- talline and para-crystalline NMR signal intensity [4] Krässig H. A., Cellulose. Structure, Acces- adding up to some 55%. sibility and Reactivity, Chap. 3. Methods of Fiber Structure Characterization. Polymer Monographs, Vol 11, Gordon and Breach Science Publishers: 43-147 (1993) [5] Larsson P.T., Wickholm K. and Iversen Given the differences in principle of operation T. A CP/MAS 13C-NMR investigation of between XRD and NMR the agreement between molecular ordering in celluloses. Carbo- similar results is judged as excellent to good. The hydr. Res. 302 19-25 (1997) difference found in the estimates of cellulose [6] Popescu C-M., Popescu M-C., Singurel content is expected since the NMR method is G., Vasile C., Argyropolulos D.S. and Wil- known to discriminate hemicellulose signal inten- for S., Spectral characterization of Euca- sity. Both methods indicate a slight increase in lyptus Wood, Appl. Spectr. 61 (11) 1168- the apparent crystallite size after bleaching while the degree of crystallinity remains unchanged. [7] Teeaar R., Serlmaa R., and Paakkari T. Further, the comparison of the degrees crystal- Crystallinity of cellulose, as determined linity determined by NMR and XRD indicate that by CP/MAS NMR and XRD methods, the NMR signal intensity interpreted as para- Polymer Bulletin 17 231-237 (1987) crystalline cellulose is detected as a crystalline [8] VanderHart D.L. and Atalla R.H. Stud- form during XRD measurements.
ies of Microstructure in Native Celluloses Using Solid-state 13C NMR. Macromol-ecules 17 1465-1472 (1984) [9] Wickholm K., Larsson P.T. and Iversen T. Assignment of non-crystalline forms The EU COST action E54 "Characterisation of in cellulose I by CP/MAS 13C NMR spec- the fine structure and properties of papermaking troscopy. Carbohydr. Res. 312 123-129 fibres using new technologies" is acknowledged 2. MUNKACSOPORT – Egyedi rostok kezelése és jellemzésük mikrotechnológiákkal sósavval, foszforsavval és cellulázzal
Paul Ander és Geoffrey Daniel CRUW, Erdei Termékek Főosztálya/Faipari tudományok SLU, PO Box 7008, SE-75007 Uppsala, Sweden Az új sósavas mód- rostanyagok közötti különbségekben. A – főként a szert haszáltuk különböző rost felületén aktív – nagy cellulázmolekulák eseté- lucfenyő, erdeifenyő, nyír- ben a glükóz volt a kibocsátott legnagyobb mennyi- fa, eukaliptusz és TMP- ségű cukor, ami nagy EG + CBH katalitikus tevékeny- rostok összehasonlítására. séget tükröz 0.8 g/l glükóz adagolása mellett.
Néhány eredményt az 1.
Az 1. ábra lucfenyő teljes hasadását mutatja
táblázatban mutatunk
1N HCl jelenlétében. A 2. ábrán 79%-os foszforsav
be: a gyári rostok savra hatására bekövetkező gömbduzzadás és felcsava- sokkal érzékenyebbek rodottvoltak, mint a laboratóri- S1 „gyöngysor" láthatók. A gömbduzzadás a umi rostok, és a nagyobb rostok tulajdonságaitól függ.
Paul Ander Vizsgáltuk a HCl hatását eukaliptuszra és nyú rostanyagok is sokkal nyírcellulóz rostokra. Ezek az eredmények azt érzékenyebben reagáltak a savra. A szinergetikai mutatják, hogy a nyír kraftcellulóz rostjai sokkal hatás miatt az N342 és a Celluclast az összes rost inkább ellenállnak a savnak, mint az eukaliptusz- nagyon erős hasadását eredményezte. A cellulázok rostok. A hosszabb nyírrostok (cca 1 mm) ellené- azonban nem mutattak különbséget a gyári és labo-
re, ezek a rostok kevésbé hasadtak, mint a 0.65 ratóriumi rostanyagok között. A HCl a fenti rostokat mm hosszú eukaliptuszrostok. (hasadás 0.22-0.35 0.7-1.7 µm között duzzasztotta, míg az N342 és a vs 0.835-1.40). Ebben az eltérésben az edények és Celluclast a rostszélességet 1–3 µm-rel csökkentet- a parenchimaszövet is szerepet játszanak.
te. A HCl bocsátotta ki a legtöbb xylózt (0.1 g/l) és nagyon kevés glükózt (0.015 g/l). Ez arra utal, hogy a HCl 80–82°C-nál az összes sejtfalrétegen áthatol, ezzel degradálva főként a hemicellulózokat. Így a xilán és a glükomannán sav hatására történő degradációjának A sósavas kezelés, a rosthosszúság megha- van bizonyos jelentősége a gyári és laboratóriumi tározása és a rostonkénti hasadás (viszonyítva a Gyári II
1. Táblázat. Gyári és laboratóriumi kraftrostok hasadása HCl (81°C, pH 0) és különböző celluláz keverékek hatására 50°C-nál. A celluláz N476- nál pH értéke 7 volt, és a többinél pedig 5. *0.3 ml; **0.6 ml enzim. Folyt. 240. oldalon WORKING GROUP 2. – Treatment and characterisation of individual fibres by microsys- Testing of pulp fibres with HCL, phosphoric acid and
Paul Ander and Geoffrey Daniel CRUW, Dept. of Forest Products/Wood Science, SLU, PO Box 7008, SE-75007 Uppsala, Sweden fibre line were: I. After cook; II. After Wash press; III. After O2; IV. After EOP; V. After D2. L -values are from HCl treatment, determination of fibre length and each sampling point before HCl-treatment [2].
cleavage per fibre was found to differentiate between pulps made in the laboratory and mill even though HCl-treatment and calculation
the same batch of spruce wood fibres was used. This Final version of the HCl-method is given in [2,4]. In
was not the case for cellulase fibre cleavage. The short, never-dried fibres are swelled in 20 ml water and reason is due to better penetration of fibre walls by 20 ml 2N HCl added to give pH 0. Incubation is then the acid at a higher temperature with release of hemi- carried out for 4h at 80-82°C with cleavage completed cellulose sugars, while cellulase activity is mainly during cooling using a stirring bar for 30 min. Finally restricted to the fibre surfaces, except in dislocations, the fibres are washed with phosphate buffer at pH 7 to with release of glucose as the main sugar. Phosphoric remove the acid. Fibre length determination was done acid probably penetrates through cracks and disloca- using a FibreMaster or a Kajaani instrument. Calcula-
tions of the S1 wall and swells the S2 fibre cell wall cre- tion: Cleavage per fibre = (L / L) – 1 were L is length
ating balloons. The number of balloons and degree of weighted fibre length distribution in mm for control in swelling reflects the history of the pulp fibre such as water (or for untreated fibres), and L is length weighted bleaching and mechanical treatment.
fibre length distribution in mm for HCl-treated fibres. HCl and Cellulase treatment
The four kraft pulps Mill I & Lab I and Mill II & Lab II were tested with HCl as above and with Novozym 476 The new pulp fibre testing method called the (monocomponent endoglucanase EG), Novozym 342 HCl-method can be used to compare different spruce, (multicomponent endoglucanase + cellobiohydro- pine, birch, Eucalyptus and TMP pulp fibres by allow- lase CBH) and Celluclast 1.5L (EG + CBH from Trichode- ing calculation of the number of fibre cleavages in rma reesei) at 50°C [4].
dislocations and other weak points [1,2]. Here fibre
cleavage using HCl and cellulase treatments are fur-
ther evaluated regarding differences in cleavage pat- Arabinose, galactose, glucose, mannose and tern, in degradation of the different fibre cell walls xylose in fibre filtrates were determined at M-real/ and in sugar release [3]. For more background see [4].
MoRe Research, Örnsköldsvik using ion chromatog- The use of phosphoric acid and fibre balloon swelling raphy and pulsed amperometric detection [4].
as a test of fibre quality is also shortly described.
Phosphoric acid swelling
Balloon swelling of fibres was performed using
79% ortho-phosphoric acid as described earlier
[5-7]
. Some balloon swelling tests were also done
with 8% LiCl in DMAC, copperethylenediamine Source and properties of kraft and TMP pulp fibres and Fe(III)-tartrate [7].
are given in [1,2]. Four kraft pulps were from two
Light microscopy. For polarized light microscopy, Scandinavian mills and called Mill I & Lab I (spruce:pine a Leica DMLB or DMLS coupled to an Image-Pro Plus relation 33:67) and Mill II & Lab II) (spruce:pine relation
84:16) [3]. Spruce kraft pulp samples along a kraft pulp
Cont. p 241 1.ábra. Lucfenyőrost HCl hatására bekövetkező teljes hasadása, 2.ábra. Lucfenyőrost gömbduzzadása feltárva a sejt belsejét diszlokációk számához) különbséget tesznek a szemben. A foszforsav valószínűleg behatol a S1 laboratóriumban vagy gyárban előállított rost- fal repedéseibe és az elmozdulások közé, és meg- anyagok között, még akkor is, hogyha ugyanazt duzzasztja az S2 rostsejtfalat, ezáltal gömböket a lucfenyőrostot alkalmaztuk. Ugyanakkor ezt hoz létre. A gömbök száma és a duzzadás foka nem tapasztaltuk cellulázos rosthasításban. A tükrözi a cellulózrost múltját, mint például fehérí- nyírfarostok nagy ellenállást mutatnak a sósavval tés és mechanikai kezelés. WORKING GROUP 2. image analysis program was used. Dislocations are most easily seen in latewood fibres.
Scanning electron microscopy
Pulp fibres and fragments (free of buffer) follow-
ing HCl or cellulase treatments were prepared and
gold sputtered as described [4,7]. Electron micro-
scopy instruments used were Philips ESEM XL 30 or
Hitachi 4500 FE-SEM.
Results and discussion
Dislocations as light bands are most easily seen in latewood fibres in polarised light and one example is
shown in Fig. 1. It was reported in Riga 2004 [8] and
in [1] that industrial (Mill) pulps, both from early thin-
Fig. 1. Spruce latewood fibre showing dislocations in pol. light nings and final cutting, were significantly more sensi-
tive to HCl cleavage indicating more dislocations than
in laboratory (Lab) produced kraft pulps from the
same spruce wood batch. Thus the HCl-method is a
valuable tool in Strength Delivery studies [1,2]. These
results have been confirmed for many kraft pulps
and one example is given in Fig. 2. In a comparison
between bleached pine and spruce kraft pulps, it was
shown that pine pulp fibres were less sensitive to HCl
cleavage than spruce kraft pulps (Fig. 3). A similar
result was obtained for pine and spruce TMP pulps.
Influence of hemicellulose
Bleached spruce pulp fibres (PH, RDH, ITC, PS)
containing 8.1, 15.9, 17.0, and 20.8 % hemicellulose,
respectively were tested with the HCl-method [2].
The corresponding cleavage per fibre were: 4.90,
3.42, 3.10, 2.43 (R2 = 0.965). Thus hemicelluloses,
Fig. 2. Cleavage of Lab and Mill spruce fibres by HCl. mainly glucomannan, may protect the cellulose from acid cleavage. Fibres from a kraft pulp fibre line
Pulp fibre samples were taken along a pulp fibre line. Strong cleavage was obtained after the wash press in point 2 indicating fibre compression and
mechanical effects in the wash press [2]. In samples
3-5, the cleavage numbers gradually decreased prob-
ably due to removal of HCl-vulnerable structures
already in the bleaching process. Thus the HCl-meth-
od can be used to study all kinds of pulps and to
evaluate pulping processes (Fig. 4).
Comparison of fibre cleavage by HCl and Cel-
Four pulps (see Table 1) were tested with HCl and
the cellulases N476 (EG), N 342 and Celluclast 1.5L Fig. 3. Cleavage of bleached pine and spruce fibres by HCl WORKING GROUP 2.
(both with EG + CBH). The last two cellulase mixtures decreased fibre width, with glucose beeing the major gave good fibre cleavage in dislocations but only HCl sugar released reflecting the catalytic activity of EG + could differentiate between Mill and Lab pulp fibres CBH giving up to 0.8 g/l of glucose.
(Table 1). N476 containing only endoglucanase had little cleavage activity.
Balloon swelling of pulp fibres
Some interesting points from Table 1: Mill fibres The morphology of balloons produced by 79% were more sensitive to acid than Lab fibres, and pulps phosphoric acid swelling [5] was studied in light- and
with a larger spruce to pine relationship were also more electron microscopy (SEM and TEM). The goal was acid sensitive. Due to the synergistic effect, N342 and to evaluate balloon swelling as a method for char- Celluclast gave very strong cleavage of all pulp fibres. acterization of spruce kraft pulp fibres [5,7,9]. The
The cellulases, however did not distinguish between Mill
studies showed that phosphoric acid was the best and Lab pulps. HCl swelled the above fibres between swelling agent as compared with LiCl/DMAc giving a 0.7-1.7 µm, while N342 and Celluclast decreased fibre slimy substance on the fibre, which hindered electron width by 1-3 µm (not shown) indicating removal of S1 microscopy studies. Very stable balloons, possible to and the outer part of S2 fibre cell walls by cellulase [4].
study in EM, were obtained in fibres with 3-4% lignin. Furthermore, HCl released most xylose (0.1 g/l) and very Cellulase-treated, bleached or mechanically affected little glucose (0.015 g/l). This indicates that HCl at 80- fibres gave rapid ballooning and further dissolution 82°C is penetrating all cell wall layers mainly degrading of the fibre. The reason for the remarkable regularity hemicelluloses. Thus degradation of xylan and gluco- of swelling in the form of "string of pearls" or if dislo- mannan by the acid seems to be of some importance cations are involved is not known with certainty. Eck- for the differences obtained between Mill and Lab pulp hart et al. [9] developed an image analysis method to
fibres. For the large cellulase molecules acting mostly study fibre swelling in copperethylenediamine and on the fibre surface; a supposition supported by the calculated degree of swelling in percent of the total fibre length. In this way an indication of outer fibre wall damage for pulps of similar type was obtained. Dislocations may be involved in this fibre swelling. Le Moigne et al. [10] recently investigated swell-
ing of bleached cotton fibres, Na-sulfite pine pulps
and Ca-bisulfite spruce pulps in N-methylmorpho-
line-N-oxide – water mixtures and in NaOH-water.
It was suggested that both the primary wall and
the outer part of the S1 wall are important in bal-
loon swelling and formation of "unswollen sections"
between the balloons (similar as in Fig. 7). This is
partly in contrast to our opinion [6,7] after using
spruce kraft pulp without primary wall, which if
present, is only 0.1-0.2 µm thin. We suggested that it
is mainly the S1 wall, which is rolled off the balloons
creating the "collars" shown in Fig. 7. In COST Action
E54 we want to continue cooperation to clarify fur-
Fig. 4. HCl cleavage of fibres from a pulp fibre line. ther the mechanisms of balloon swelling of different Pulp type
Table 1. Cleavage of Mill and Lab kraft pulp fibres by HCl (81°C, pH 0) and by different cellulase mixtures at 50°C. Cellulase N476 was run at pH 7, and the others at pH 5. *0.3 ml; **0.6 ml enzyme. WORKING GROUP 2. Spruce fibre balloon swelling in phosphoric acid [6,7].
Figs 5-6: Polarized light microscopy, S2 and S3 cell walls are shown in Fig. 6. cellulose and wood fibres. Another line of investiga-
tion is to use Raman spectroscopy to see whether
phosphoric acid is converting cellulose I to cellulose
II in bleached fibres [11].
HCl-effects on Eucalyptus and birch pulp fibres were also tested [12]. These results indicate that birch
kraft pulp fibres (ca 1 mm) are more resistant to HCl
than the 0.65 mm long Eucalyptus fibres. Despite
longer birch fibres, they were poorly cleaved as com-
pared with Eucalyptus fibres (cleavage 0.22-0.35 vs
0.835-1.40). Vessels and parenchyma may be involved
in these differences.
– The HCl-method can be used to determine Spruce fibre balloon swelling in phosphoric acid [6,7].
dislocations and other weak points in different Fig. 7. SEM micrograph of balloons and rolled off S1 "collars". pulp fibre types and may be a complement to wet zero span measurements and other paper – HCl penetrates deeply into the fibre cell walls, while cellulases act mostly on the fibre surfaces – Fibre length determination in Fibermaster or and only penetrate the fibre to a certain extent Kajaani or other instruments can be done in in dislocations, that are supposed to be of a more many paper and fibre research laboratories.
– Spruce pulp fibres are more sensitive to HCl – Dislocation cleavage and/or cleavage of β-1,4- than pine pulp fibres. glucosidic bonds in cellulose by HCl or cellulase – Pulp samples from fibre lines can be studied give little sugar release and the amount of sug- with the HCl-method.
ars cannot be used to differentiate between Mill – Hemicellulose degradation by HCl seems to be and Lab pulp fibres.
of importance for the differentiation between – Fibre swelling and ballooning in phosphoric Mill and Lab pulp fibres, while cellulases mainly acid or copperethylenediamine coupled with release glucose from the fibre surfaces causing image analysis may be used for pulp fibre char- decreased fibre width.
WORKING GROUP 2.
[6] Ander, P. Dislocations and balloon swelling in spruce kraft pulp fibres – Effect of cellu- This research was supported by WURC, Wood lases, xylanase and laccase/HBT. Progress in Ultrastructure Research Centre, established at SLU and Biotechnology 21, BIOTECHNOLOGY IN THE supported by VINNOVA and the following eight Swed- PULP AND PAPER INDUSTRY: 8th ICBPPI. Eds: ish pulp & paper companies: Holmen, Korsnäs, Kappa L. Viikari and R. Lantto, Elsevier Science B.V., Kraftliner, M-real, SCA, StoraEnso, Sveaskog and Södra Cell and the chemical company Eka Chemicals. Many [7] Ander, P. and Daniel, G. Morphology of spruce thanks to Lars Hildén, Holmen Paper & CRUW for the fibre dislocations as studied by balloon swell- gift of Novozyme cellulases and for valuable discus- ing and acid cleavage – light and electron sions regarding cellulase testing. microscope observations. COST Action E20, "Wood Fibre Cell Walls: Methods to Study Their Formation, Structure and Properties", Eds: U. Schmitt, P. Ander, J.R. Barnett, A.M.C. Emons, G. Jeronimidis, P. Saranpää, and S. [1] Ander P., Daniel G., Garcia-Lindgren C. and Tschegg. Swedish University of Agricultural Marklund A. Characterization of industrial Sciences, Uppsala, Sweden. ISBN 91-576- and laboratory pulp fibres using HCl, Cellu- 6803-5, pp. 203-215 (2004) lase and FiberMaster analyses. Nordic Pulp [8] Ander, P. and Daniel, G. A novel method and Paper Res. J. 20 (1) 115-120 (2005) to compare industrial and laboratory pulp [2] Ander P. and Daniel, G. 2006. Dislocation fibres using hydrochloric acid and Fibre- counting and comparison of pulp fibre Master analyses. Proc. Eighth European properties after HCl-treatment and fibre Workshop on Lignocellulosics and Pulp. length determination. Proc. 5th Plant Bio- August 22-25, 2004, Riga, Latvia, pp. 49-52. mechanics Conference, Stockholm, Vol. ISBN 9984-19-611-9 (2004) I. August 28 – September 1, 2006. Ed.: L. [9] Eckhart, R., Hirn, U., Eichinger, R., Bauer, W. Salmén. STFI-Packforsk, Stockholm, Swe- Practical application of a new method to den, ISBN 91-86018-12-4, pp. 169-174.
evaluate mechanical and chemical dam- [3] Ander P. and Daniel, G. 2007. Degradation of age of pulp fibres. 32nd Internat. DITP Symp., softwood pulp fibres by HCl and Cellulases Bled, Slovenia 9-10 Nov. 2005.
reflects different action on cellulose and [10] Le Moigne, N., Pannetier, C., Höfte, H., hemicelluloses. The Third Workshop on Cel- Navard, P. Swelling and dissolution mecha- lulose, Regenerated Cellulose and Cellulose nisms of natural cellulose fibres. The Third Derivatives. Karlstad University, Karlstad, Workshop on Cellulose, Regenerated Cel- November 13-14, 2007, p. 36-40. Available at lulose and Cellulose Derivatives. Karlstad KaU Karlstad, KTH Stockholm, SLU Uppsala University, Karlstad, November 13-14, 2007, and STFI-Packforsk Stockholm.
p. 24-25, and pers. comm. with Nicolas Le [4] Ander, P., Hildén, L., and Daniel, G. Cleavage Moigne Nov. 2007.
of softwood kraft pulp fibres by HCl and Cel- [11] Ander, P., Vig, A., Szabo, A.Unpublished lulases. Bioresources 3 (2) 477-490. (2008) [5] Steenberg, B. Beating process studied by [12] Ander, P. Effects of phosphoric and hydro- fiber swelling. Svensk Papperstidning 50: chloric acids on kraft pulp fibres. COST 11B, 155-163 (1947) Action E54, Graz, Austria, 10-11 April 2008.
WORKING GROUP 2.
Ramesh-Babu Adusumalli, Patrick Schwaller, Johann Michler Anyagmechanikai és nanostruktúra laboratórium Empa – Anyagtechnika & Technológia Feuerwerkerstr. 39; CH-3602 Thun, Svájc Telefon: +41 33 228 2996; Fax: +41 33 228 4490 Különböző típusú rost vizsgálatok nem hoztak ígéretes ered- rostanyagokat, bele- ményeket. Az egyedi rost sejtfalának MTS értve fenyő-, lombos, Nano indenterrel [alakváltozást, bemélyedést fehérített és fehérítet- mérő szerkezet] végrehajtott keménységi len cellulózokat vetet- vizsgálata a sejtfal elhelyezésének nehéz- tünk alá szakítási vizs- sége miatt nem volt sikeres. Jelenleg a gálatoknak. Az egyedi sejtfal keménységét Tribo nanoindenterrel rostok vizsgálatához mérjük, amelyre AFM van felszerelve, és a papírkeretbe rögzített rost hosszanti irányában a bemetszéseket rostokat alkalmaz- MTS nanoindenterrel végezzük, és mindket- tunk. A cellulózrostok tő kiváló eredményeket mutatott az előzetes törékeny természete miatt a javasolt egyedi Micromechanics of single pulp fibres
Ramesh-Babu Adusumalli, Patrick Schwaller, Johann Michler Mechanics of Materials and Nanostructures Laboratory Empa - Materials Science & Technology Feuerwerkerstr. 39; CH-3602 Thun, Switzerland Phone: +41 33 228 2996; Fax: +41 33 228 4490 Pulps of various grades including softwood, hardwood, bleached, unbleached were subjected to tensile testing. Paper frame set-up was adopted to test the single pulp fibres. Due to the brittle nature of pulp fibres, proposed single fibre tests did not yield promising results. Hardness measurements on single fibre cell-wall using MTS Nano indenter were not successful due to the difficulties in locating the cell-wall. Presently cell-wall hardness is measured using Tribo nano indender equipped with AFM and indents on the fibre longitudinal direction is performed using MTS Nano indenter, both revealed excellent results during preliminary tests.
Az egyedi rost-rost kötések
kötési felületének mérése
Lisbeth Kappel1, Ulrich Hirn1, Wolfgang Bauer1, Robert Schennach2 Grazi Műszaki Egyetem 1Papír- Cellulóz- és Rosttechnológiai Intézet Papírszilárdság felületi kémiai és fizikai alapok CD-Laboratóriuma Kopernikusgasse 24/II 8010 Graz 2Szilárdtest Fizikai Intézet Papírszilárdság felületi kémiai és fizikai alapok CD-Laboratóriuma Petersgasse 16/II 8010 Graz Ez az előadás az Minden egyes vágásnál képelemzéssel egyedi rost-rost kötések határoztuk meg azt a vonalat, ahol a rostok kötési felületének meg- érintkeznek, és megmértük ennek hosszát. határozási módszerét A kötési területet úgy számítottuk ki, hogy a mutatja be mikrotommal kötésvonal hosszát megszoroztuk a vágás vas- történő sorozatos sze- tagságával (3 µm).
letelés és képelemzés A kötési terület mellett a rostok számos mor- alapján. A kötési terü- fológiai paraméterét és kötési területét mértük let méretét és három- képanalízissel. A rostkeresztmetszet, a rostke- dimenziós struktúráját rület, rostfal vastagsága, a rost összeomlása, a a keresztmetszeti rost- rost szélessége, és a nem tökéletes kötés foka Lisbeth Kappel morfológiával együtt átfogó képet adnak a rost-rost kötésről.
értékeltük. A lyukakat és 87 rost-rost kötést elemeztünk lineáris korre- átfedett, de nem kötött éleket pótlólag mértük. lációval, amely megmutatta, hogy a rostszélesség Az egyedi rost-rostkötések hidegen polime- ad magyarázatot a kötési terület majdnem 50%- rizálódó gyantába vannak beágyazva. Kezelés ára. Ugyanakkor a többi morfológiai paraméter után a kötési terület háromdimenziós struktúráját (rostfal vastagsága, rostkerület, rostkeresztmet- elemeztük automatikus mikrotom rendszer alkal- szet területe), 2 rost keresztezésének szöge és a mazásával. A mikrotommal három mikrométer nem tökéletes kötés is fontos szerepet játszanak, vastagságú szeleteket vágtunk le, és a vágási és nem hagyhatók figyelmen kívül. Ezek az ered- területet minden egyes vágás után automatiku- mények csak egyszerű korreláción alapulnak, san megjelenítettük. Ez a rost keresztmetszeté- a további elemzésekhez lineáris regressziós ből számos képet eredményez, amely a rost-rost modellezést kell végezni, hogy megtaláljuk a kötés háromdimenziós alakját reprezentálja.
kölcsönkapcsolatokat és redundanciákat.
ORGANIZATORTechnical Association of Paper and Printing Industry – Budapestpnyme@mtesz.hu – www.pnyme.hu WORKING GROUP 2.
Measuring the bonded area of
individual fiber-to-fiber bonds
Lisbeth Kappel1, Ulrich Hirn1, Wolfgang Bauer1, Robert Schennach² Graz, University of Technology 1Institute for Paper, Pulp and Fiber Technology CD-Laboratory for surface chemical and physical fundamentals of paper strength Kopernikusgasse 24/II 8010 Graz ²Institute for Solid State Physics CD-Laboratory for surface chemical and physical fundamentals of paper strength Petersgasse 16/II 8010 Graz Analysis of geometrical and morphological parameters of 87 single fiber-to-fiber bonds will This paper presents a method for the deter- help to explain the governing factors for the size mination of bonded area of single fiber-to-fiber of bonded area.
bonds, based on microtome serial sectioning and image analysis. The size and three dimen-sional structure of the bonded area are assessed Measurement of bonded area
together with cross sectional fiber morphology. Holes and overlapping but unbonded edges are The method for the determination of the bonded area is based on microtome serial sec- 87 fiber-to-fiber bonds of unbleached and tioning and image analysis. It yields the size of unbeaten softwood Kraft pulp were analyzed. bonded area together with the three-dimension- Correlations between bonded area and mor- al structure of the bonded area and morphologi- phological parameters show influences on size cal fiber parameters. of bonded area. In this study only single correla- The samples are embedded in a gelatine tions were performed, so linear modelling and capsule using a cold-polymerizing resin. After analysis of interrelations and redundancies will curing, the three dimensional structure of the be part of future work.
bonding region is analyzed using an automated
microtomy system [1]. Slices with a thickness of
3 µm are repeatedly cut off the embedded sam-
ple with the microtome and the cutting area is imaged automatically after every cut with a pixel Paper strength depends on the strength of size of 0,161 µm. This yields a stack of images of single fibers and the strength of the fiber-to- the fiber cross section, representing the three- fiber bonds. The strength of the fiber-to-fiber dimensional shape of the fiber-to-fiber bond. bonds again depends on the size of the bond- Three exemplary light microscope images ed area and on the specific bonding strength. at different cutting positions are given in Fig. 1.
Measuring the actual size of the bonded area The first image (a.) shows the edge of the bond, helps to understand the governing factors for the fibers contact region is small. The left fiber fiber-to-fiber bond strength. In this study we is fully collapsed and folded, the right fiber on investigate the distribution of the bonded area the other hand is fully collapsed and unfolded. for individual fiber-to-fiber bonds. We propose The following two images (b. and c.) proceed a novel method for the determination of bonded deeper into the bond. Because of the irregular- area based on microtome serial sectioning. ity of the fold the contact between the fibers is WORKING GROUP 2.
Fig 1 a., b., c.: Microscope images of fiber-to-fiber bond cross sections. d.: Segmented fibers of c. with bonding line. e.: 3-dimensional representation of bonded area by plotting the bonding lines. interrupted. Fig. 1 (b.) shows, that the fibers are dure described by [2]. Fiber cross sectional area,
only partly bonded. In the upper part of the bond fiber perimeter, fiber wall thickness, fiber col- the fibers are separated. In the next image (c.) lapse, fiber width and incomplete bonding give a the fibers are in contact over a greater length, comprehensive picture of the fiber-to-fiber bond.
but the contact is interrupted. Segmentation of the fiber regions is per- formed by the operator, the fiber outline is drawn into the microscope image by hand (Fig. 1 d.).
From these fiber outline images the mor- Bonded area and morphological parameters phology of the bonding region and the fibers is of 87 fiber-to-fiber bonds of unbleached unbeat- determined using image analysis.
en softwood Kraft pulp were analyzed. We tried For bonded area measurement we consider to find linear correlations between bonded area these fiber regions to be bonded, where the fibers in the microscope images are in direct The mean value for bonded area is 1130 contact. This region is determined image ana- µm² and standard deviation is 602 µm². Fig.
lytically, yielding a bonding line for every cut, as 2 shows a histogram of all values for bonded
it is indicated by the white line in Fig. 1 (d.). area, the distribution is positively skewed. Bonded area is calculated from bond line length multiplied with the cut thickness (3 µm). A 3-dimensional representation of the bonding region is obtained by plotting all lines of one bond (Fig. 1e.). The rightmost line corresponds to the length where the fibers were in contact in the first cut (a.). The line which is marked gray belongs to the cut of the label image (d.). The interruption caused by the fold of the left fiber can be seen. The distance between the lines is equivalent to the cut thickness (3 µm).
In addition to bonded area several morpho- logical parameters of fibers and bonding region Fig. 2 Histogram of values for bonded area, mean=1130 are measured image analytically using a proce- µm², variance=602 µm², skewness=0.9495. WORKING GROUP 2. Determining factors for bonded area
ing in Fig. 4 illustrated this relationship. Bigger
fiber width leads to larger bonded area.
The influencing factors on the size of bond- The influence of fiber width is also reflected ed area will be discussed in the following sec- in fiber perimeter (Fig. 3c), as bigger fiber width tion, based on the results for bonded area and leads to a bigger fiber perimeter. The same morphological parameters. correlation is also valid for fiber cross sectional Fig. 3 shows correlations between bonded
area and morphological parameters, the R² Incomplete bonding (Fig. 3d) also seems to value is given in each diagram.
be important for the size of bonded area. This Fig. 3 (a) shows that fiber width has the big- shows that only consideration of morphologi- gest impact on size of bonded area. The draw- cal fiber parameters is not enough, as in some Fig. 3 Correlations between bonded area and morphological parameters (fiber width, fiber cross sectional area, fiber perimeter, incomplete bonding, fiber wall thickness and crossing angle) WORKING GROUP 2.
cases quite large unbonded areas have to be fiber morphology and bonded area morphology might contribute to a comprehensive under- Fiber wall thickness (Fig. 3e) is closely relat- standing of fiber-to-fiber bonding. ed to conformability. Summerwood fibers with a The analysis of 87 fiber-to-fiber bonds thick fiber wall cannot conform so well to each showed that fiber width explains almost 50 % of other and so bonded area gets smaller, though bonded area. Also other morphological param- the influence is far smaller than the influence of eters (fiber wall thickness, fiber perimeter, fiber cross sectional area), crossing angle and The deviation of the crossing angle from incomplete bonding play an important role and right angle also has an influence on size of have to be considered. bonded area (Fig. 3f). Bigger deviation from Please note that only single correlations right angle leads to bigger bonded area, as can were analyzed in this study. Linear modeling also be seen in Fig. 4.
will have to be performed in order to investigate interrelations and redundancies.
The method introduced in this paper seems to be a useful tool to investigate bonded area The authors want to acknowledge Mondi together with the morphology of the fiber cross Group and the Christian Doppler Society for sections and the bonding region. The method is funding this work.
able to measure incomplete bonding (holes and overlapping but unbonded regions at the border of the bond). This combined measurement of [1] Wiltsche, M., Donoser, M., Bauer, W. and Bischof, H.: A New Slice-Based Concept for 3D Paper Structure Analysis Applied to Spatial Coating Layer Formation, in Advanced in Paper Science and Tech-nology, Fundamental Research Sympo-sium, Cambridge, 853 (2005) [2] Kritzinger, J., Donoser, M., Wiltsche, M. and Bauer, W.: Examination of Fiber Transverse Properties Based on a Serial Sectioning Technique, Progress in Paper Physics Seminar Proceedings, Helsinki, Fig. 4 Influence of fiber width and crossing angle on size of bonded area. 3.MUNKACSOPORT – Rostok finomszerkezetének hatása papírképző tulajdonságaikra, valamint kémiai és enzimatikus reaktivitásukra Rostanyagok víztelenítése és az őrlés
hatékonyságának javítása celluláz kezeléssel
Ivo Valchev, Petar Bikov Kémiai Technológiai és Fémipari Egyetem 8KL Ohridski, 1756 Szófia, Bulgária e-mail: ivoval@uctm.edu rostanyaggal, a „Mayr-Melnhof" AD –Nikopol által biztosított festéktelenített rostanyaggal, a Svilocell AG által biztosított fehérített cellulózzal, valamint fehérített brazil eukaliptusz rostanyaggal végeztük.
Az enzimes kezelést a Novozymes AS FiberCare® D celluláz termékével végeztük, amely nagyon hatékony, de ugyanakkor kíméletes a ros-tokkal. 0,05–0,2% enzim 20–45%-kal javítja az OCC- rostanyag víztelenedését, illetve max. 25%-kal az őrlésfokot. Nagyobb négyzetmétertömegű Ivo Valchev Petar Bikov termékek gyártásában a szárító gőzfogyasztása akár 4%-kal is csökkenhet. Az enzimes kezelés A papír- és karton gyártásában a leginkább kapott eredményeit a másodlagos rostok kol- energiaigényes folyamat az őrlés és a rostanya- loid anyagainak részleges destrukciójával lehet gok szárítása. A celluláz termékek alkalmazása értelmezni. Ez a gélfrakció megtartja a vizet, az egyik legkorszerűbb módszer a víztelenítés és és a másodlagos rostok lassú víztelenedését az őrlés hatékonyságának javítására. Ha az őrlés okozza. A hulladékpapír FiberCare® D kezelése előtt adagolunk enzimet, annak hatása eltérő lassan növeli a rostanyag szakadási hosszát, míg lesz az őrlés utáni kezelés hatásától. Az őrlés a tépő- és repesztési mutató csökken.
előtti alkalmazás jobb őrlési hatékonyságot Az „Mayr Melnhof" AD által szállított fes- eredményez, míg az őrlés utáni kezelés nagyobb téktelenített rostanyag víztelenedésében vizs- őrlésfokot eredményez. Tény, hogy a celluláz gált cellulázhatás kisebb enzimaktivitást mutat, a gél formájú struktúrák lebomlásához vezet. amely nagyobb FiberCare® D terhelést tesz szük- Ezeket a víztelenedés javítására lehet alkalmazni ségessé ugyanolyan víztelenedés eléréséhez. hidrolízis révén a rostokban, finomanyagokban Az oldatban a redukált cukrok vizsgálatának és oldott kolloidanyagokban jelenlévő cellulóz- eredményei körülbelül 0,4-0,5%-os rostvesztesé- és hemicellulóz leginkább hozzáférhető részei- get mutatnak, ami a kolloid anyagok oldódásával ben. A megfelelő módon alkalmazott cellulázok kapcsolatos. A papír minőségek és a rostanyag növelhetik vagy helyreállíthatják a rostszilárdsá- víztelenedése közötti optimális egyensúlyt ala- got, csökkenthetik az őrlési időt, és növelhetik a csony szintű enzimterhelésnél lehet elérni. rostok közti kötést fibrilláción keresztül. A FiberCare® D hatása az őrlés előtti kémiai Ennek a munkának a célja az, hogy vizs- rostanyagkezelésben elősegíti az őrlésfok növe- gáljuk az új celluláztermékeknek az őrlésre, a kedését 14°SR-rel eukaliptuszra, és 24°SR-rel a víztelenedésre és a rostanyag szilárdsági tulaj- Svilocell rostanyagára. Az enzimadagolásnak a két donságaira gyakorolt hatását.
rostanyag típus szilárdsági tulajdonságaira gyako- A vizsgálatokat a Bulgáriából, az „Duropack- Trakia-Papír" AD – Pazardjik által biztosított OCC Folyt. 254. oldalon WORKING GROUP 3. – The impact of the fine structure of fibres on their papermaking properties and their chemical and enzymatic reactivity Pulp dewatering and refining efficiency improvement
by cellulase treatment
Ivo Valchev, Petar Bikov University of Chemical Technology and Metallurgy 8 Kl. Ohridski, 1756 Sofia, Bulgaria e-mail: ivoval@uctm.edu post-refining treatment results in increased furnish freeness. A combination of the two can provide opti- Refining and pulp drying are the most energy- mized strength and drainage benefits [1]. Beating
intensive processes in the production of paper and and refining are mechanical processes that enhance boards. The usage of cellulases products is one of fibrillation and inter-fiber bonding. Properly applied, the modern methods to improve dewatering and cellulases can enhance or restore fiber strength, reduce beating times, and increase inter-fiber bond- The enzyme treatment was performed with the ing through fibrillation. A correctly applied enzyme Novozymes AS cellulase product FiberCare® D.
treatment provides a tool that can improve recycled The carried out investigation shows the positive paperboard operations. This is accomplished by treat- effect of enzyme treatment on the secondary fiber ing the refined stock with an enzyme blend to recov- dewatering. The obtained results of enzyme action er a portion of the freeness typically lost through can be interpreted by partial destruction of colloidal refining. A pre-refining enzyme treatment can help substances of secondary fibers. the papermaker meet strength tests more readily The effect of enzyme treatment on the pulp through improved refining efficiency. Mill experience strength properties shows insignificant increasing of has shown that a combination of these two methods breaking length, while the tear index and the burst can provide strength and drainage benefits. index decrease. Probably the FiberCare® D action at low Distinguishing feature of secondary fibers is the enzyme charge contributes an improvement on the breaking down of cell walls, causing liberating fine paper structure independent of fiber destruction proc- particles, which grow swollen and change in gel form. esses. Optimal balance between paper qualities and They retain water, slow down the dewatering, impede pulp dewatering is reached at low level enzyme charge.
drying, and causes over consumption of chemicals in The pre-refining cellulase treatment of Svilocell the paper production. It is a standing fact that cel- and eucalyptus bleached pulp significant improves lulase lead to breaking down the gel form structures beating efficiency without pulp strength properties [1, 2]. They can be applied to improve the drainage by
loss. The influence of enzyme treatment on the pulp hydrolyse the most accessible parts of the cellulose yield and waste water pollution are not significant. and hemicellulose present in the fibers, fines and dis- FiberCare® D is able to waste paper dewatering solved colloidal substances [3].
improvement and is a prerequisite for dryer steam Jackson et al. [4] suggest that enzymes can
consumption decreasing, refining energy costs sav- either flocculate or hydrolyse fines and remove ing and paper machine capacity increasing.
fibrils from the surface of large fibres. According to these authors, the enzyme-aided flocculation occurs when a low enzyme dosage is used. In this case, fines and small fibre particles aggregate with each other or with the larger fibres, decreasing the amount of Cellulase pulp treatment has been investigated small particles in the pulp and consequently improv- for several years, with the goal of achieving improved ing pulp drainage. For higher enzyme concentra- refining efficiency and fibre dewatering. There are two tion, flocculation becomes less significant, and methods for enzyme treatment. Addition of enzyme fragmentation of the fibres begins to predominate. prior to refining has a very different effect compared Numbers of authors observe pulp strength proper- with a post-refining treatment. Pre-refining applica-tion results in improved refining efficiency, while a Cont. p. 255 rolt hatását vizsgálva javulást mutattak ki a szaka- A másodlagos rostanyagok FiberCare® D dási hosszban, míg a tépési mutatóra a FiberCare® celluláz kezelésével folytatott vizsgálatok lehe- D alacsony mennyiségben nem gyakorolt negatív tőséget mutatnak a rostanyag víztelenedésének hatást. Azt is megfigyeltük, hogy az eukaliptusz rostanyag 40°SR őrlésfokát 20 perccel hamarabb Optimális enzimadagolás mellett a szakadási értük el FiberCare® D kezeléssel. Ugyanakkor a hossz javulását figyeltük meg, mivel a celluláz rostanyag szilárdsági tulajdonságainak függése főleg az oldott kolloidanyagokra van hatással, és a tépési mutatók és a szakadási hossz esetében csak enyhén csökkenti a rostanyaghozamot.
hasonló. Ezért az elért jelentős őrlésjavulás adott A FiberCare® D-hatékonyság a másodlagos rostok őrlésfokon, FiberCare® D kezeléssel 0,05%-os ala- típusától függ, és az enzimaktivitás töltőanyagok és csony enzimadagolás mellett nem befolyásolja rostanyag-adalékok jelenlétében csökken. Az őrlés a rostanyag szilárdsági tulajdonságait, melyeket előtti enzimes kezelés lényegesen javítja az őrlés kisebb őrlési energiaigénnyel is el lehet érni. A hatékonyságát anélkül, hogy rontaná a rostanyag FiberCare® D optimális adagolása mellett (0,025% szilárdsági tulajdonságait. Az enzimeknek a rost- a Svilocell rostanyag és 0,05% az eukaliptusz rost- anyag őrlésére vagy a papírhulladék víztelenedésére anyag esetében) 0,2%-nál kevesebb cukor kelet- gyakorolt hatásának kialakítása előfeltétele annak, kezik. Ezért az enzimes kezelés eredményeként a hogy csökkenjen a szárító gőzfelhasználása, illet- hozamveszteség és a szennyvíz szennyezettsége ve őrlési energiaköltség-megtakarítást és papírgépi kapacitásnövekedést tudjunk elérni.
WORKING GROUP 3.
ties decreasing by rise of enzyme quantities and by Pulp beating was performed with Jokro mill increase reaction time [5, 6, 7].
according to ISO 5264-3 at duration from 10 to 50 Surface properties may be modified, not only because of enzymatic hydrolysis of the outer layers The degree of refining was determined on the of the fibre, but also because of the adsorption of Schopper Riegler device according to ISO 5267. The enzyme molecules onto the fibre surface. It could rate of dewatering was determined on the same be speculated that changes in fibre–water interac- tion, induced by the presence of enzyme molecules, Pulp strength properties: breaking length, tear might be the factor responsible for drainage and index and burst index were determined according strength modification [8].
to the ISO 1924, ISO 1974 and ISO 2758 respec- The purpose of this work is to investigate the effect of the new cellulase product on the refin-ing and dewatering improvement and on the pulp strength properties.
Results and discussion
The effect of FiberCare® D treatment on the dewatering time and refining degree of Duropak
- Trakia-Papir OCC pulp is shown on Fig. 1 and Fig.
The investigations were performed with OCC 2. The enzyme charge 0.05–0.2% improves the
pulp supplied by "Duropak – Trakia-Papir" AD pulp dewatering by 20–45% and refining degree – Pazardjik, deinking pulp provided by "Mayr-Mel- up to 25% respectively. In the production of the nhof" AD – Nikopol, bleached pulp supplied by heavier weight, dryer steam consumption is able to Svilocell AD – Bulgaria and with bleached Brazilian decreased by over 4%.
eucalyptus pulp.
The obtained results of enzyme action can be The enzyme treatment was performed with the interpreted by partial destruction of colloidal sub- Novozymes AS cellulase product FiberCare® D, which stances of secondary fibers. That gel fraction retains is designed to be effective, yet gentle on fibers. This water causing slow dewatering of secondary fibers.
is accomplished because FiberCare® D takes advan- Similar study of cellulase action on the pulp tage of Novozymes' proprietary mono-component dewatering is conducted with deinking pulp sup- cellulase technology, resulting in a product that is plied by "Mayr-Melnhof" AD. Typical feature of that highly specific and targeted in its action.
pulp is the present of fillers (basic CaCO3), pulp The enzyme treatment conditions were as fol- additives and mechanical fibers. It is found a lower lows: pulp consistence 6 and 10%, temperature enzyme activity with respect to that pulp, which 60°С, reaction time 60 min., enzyme charge 0.025 determines on the higher FiberCare® D charge for – 0.5 % and pH 4 – 7.
achievement the same dewatering. The reducing sugars were determined according The effect of enzyme treatment on the pulp to a DNS method [8].
strength properties is present in Table 1. As it is
Fig 1. Influence of enzyme charge on the pulp dewatering rate, Fig 2. Effect of enzyme charge on the pulp refining degree, (pH 5, T=60°C and t = 60min) (pH 5, T=60°C and t = 60min) WORKING GROUP 3.
Duropak - Trakia-Papir OCC pulp Mayr-Melnhof – Nikopol deinking pulp Table 1. Effect of FiberCare® D charge on the waste paper strength properties Fig. 3. Influence of enzyme charge Fig. 4. Effect of enzyme treatment (pH 4.5, T=60°C, t=60min) on the refining efficiency on the rate of eucaliptus pulp beating Svilocell pulp, pH 6.5, T=60°C, t = 60min Eucaliptus pulp, pH 4.5, T=60°C, t = 60min Table 2. Influence of pre-refining cellulase charge on the pulp strength properties Fig. 5. Influence of enzyme treatment on the eucalyptus pulp Fig. 6. Effect of enzyme charge on breaking length - tear ind. dependence the reducing sugars formation WORKING GROUP 3. shown the breaking length slowly increases by the It is observed breaking length improvement in enzyme charge, while the tear index and the burst the optimum enzyme dosage as the cellulase affects index decrease. Probably the FiberCare® D action at mainly on the dissolved colloidal substances and low enzyme charge contributes an improvement on slightly reduces the pulp yield.
the paper structure independent of fiber destruc- FiberCare® D efficiency depends on the type of secondary fibers and enzyme activity decreases on The results of analysis of reduced sugars in the the presence of fillers and pulp additives.
solution show fiber losses about 0.4–0.5 % which The pre-refining enzyme treatment significantly are connected with dissolving of colloidal substanc- improves beating efficiency without pulp strength es. Optimal balance between paper qualities and properties deterioration. At optimal FiberCare® D pulp dewatering is reached at low level enzyme dosages 0.025%–0.05% the yield loss and waste water pollution are not significant.
It is studied the effect of cellulase charge in Established enzyme effect on the pulp beating pre-refining chemical pulp treatment on the pulp or waste paper dewatering is a prerequisite for dryer beating efficiency. The results obtained for the two steam consumption decreasing, refining energy types of bleached pulp, presented in Fig. 3, show a
costs saving and paper machine capacity increas- total refining degree increase with 14°SR and 24°SR for eucalyptus and Svilocell pulp respectively. The performed investigation on the effect of enzyme charge on the strength properties of the two types of pulp show improvement on the breaking length, while the tear index is not adversely affected by [1] Braian R. Morgan: Enzyme treatment FiberCare® D at low dosage (Table 2).
improves refining efficiency, recycled fiber The influence of enzyme action on the rate of freeness, Pulp and Paper, 9 119-121 (1996) eucaliptus pulp beating can be seen on the Fig.
[2] Skartaunm P., Reinhardt B., Trasser G. 4. It is observed that pulp refining degree 400SR is
– Enfluss der Enzyme als Entwaesserungs reached for 20 min. less in the case of FiberCare® D – und Hilfsmittel bei der Mahlung in der treatment. In the same time the pulp strength prop- Papierindustrie, PTS – VB 02/95 – PTS-TUD- erties dependence between tear index and break- Symposium "Zellstofftechnik fuer Papier" , ing length is a common relation for enzyme treated 1995, 5, Dresden.
and untreated pulp. (Fig. 5).
[3] Valtschev I, Bentscheva S., Christova E., Ein- Therefore the obtained significant beat- fluss der enzyme bei der veredlung von ing improvement to a given refining degree by sekundaerfaserstoffen, Wochenblatt für FiberCare® D treatment at low enzyme dosage up papierfabrikation, 20 1348-1351 (2001) to 0.05% is not affected on the pulp strength prop- [4] Jackson, L. S., Heitmann, J. A. and Joyce, T. erties, which can be developed with less refining W. "Enzymatic modifications of secondary energy requirements. fibre", Tappi Journal 76 (3), 147–154 (1993) The obtained reducing sugars as a result of cellu- [5] Miletky F. Biotechnology in pulp and paper lase treatment are in the range up to 0.4 % based on industry, Viena, Austria, 11-15 June, 1995.
pulp in relation of enzyme charge and type of pulp [6] Scott L. Jackson, J. A. Heitman, T. W. Joyce, (Fig. 6). At optimal dosage of FiberCare® D (0.025%
Enzymatic modification of secondary fiber, for Svilocell pulp and 0.05% for eucaliptus pulp) the Tappi, 76 (3) 147-154 (1993) generated sugars are less of 0.2%. Therefore in the [7] Stock G., H. Pereira, T. Wood, E. Dusterhoft, result of enzyme treatment the yield loss and waste Upgrading recycled pulps using enzymatic water pollution are not significant.
treatment, Tappi 78 (2) 79 (1995) [8] Pala H., M. Mota and F.M. Gama, Enzymat- ic Modification of Paper Fibres, Biocataly- sis and Biotransformation, 20 (5), 353-361 (2002) The carried out investigations on cellulase treat- [9] G. Miller, Use of Dinitrosalicylic Acid Reagent ment of secondary fiber materials by FiberCare® D for Determination of Reducing Sugar, Anal. show opportunity for significant improvement of Chem. 31 426-428 (1959) pulp dewatering.
Hogyan hat az enzimes kezelés
a rost tulajdonságaira?
Michael Lecourt1, Pierre Nougier, Adrien Soranzo, Sandra Tapin-Lingua and Michel Petit-Conil FCBA, BP251, 38044 GRENOBLE Cedex 9, FRANCE Az enzimek világ- láncok irányában. Ez igazolta azt a feltevést, szerte nagy mennyiség- hogy ezek az enzimek meglehetősen tiszták, ben és számos alkalma- és hogy működésük a hemicellulózok irányában zásban használt vegyi korlátozott volt. A cellulázkoncentráció hatása a anyagok. Ezeket első- viszkozitás csökkenésében mutatkozott meg. sorban az élelmiszer- 25%-os csökkenést figyelhettünk meg a leg- iparban és mezőgaz- alacsonyabb koncentrációnál. 1.000-szer több celluláz adagolásával a viszkozitás megfelező- Az enzimek előállításá- dött. A cellulózlánc hasadása nem volt arányos ban jelenleg végbement az enzimkoncentrációval. Az enzimmobilitás és fejlődés lehetővé tette, a rost mentén a degradációra rendelkezésre álló Michael Lecourt hogy tiszta egynemű helyek is szerepet játszottak és hatással voltak komponenseket állít- az enzim hatékonyságra. Őröletlen cellulóz sunk elő. Így lehetővé vált az enzimek felhasz- tulajdonságait mértük próbalapokon, ami jobb nálása a rostelőállítás folyamataiban is.
kötési potenciált mutatott cellulázok alkalmazá- Rostanyag szuszpenziókhoz különböző sával, és tisztán mutatta a vízretenció értéknek enzim típusokat adagoltunk annak érdeké- növekedését. Eközben nagyobb fehérséget is ben, hogy meghatározzuk, milyen lesz a hatás mértünk hemicelluláz alkalmazásakor. Őrlés az ilyen vegyszerekkel kezelt rostok eseté- után a különbségek nőttek. Az alkalmazott ben. A cellulóz viszkozitásváltozásait mértük enzimtől függően a szakadási hossz maximum eukaliptusz és fenyőfa cellulózokon. Az enzim 25%-kal volt magasabb, a tépési mutató 10%- típusától függően a kezelés következményei kal, hasonló energiafogyasztás mellett.
eltérőek voltak. A fenyőcellulóz viszkozitása volt a leginkább érintett cellulázzal történő kezeléskor, összehasonlítva az eukaliptusszal. A maximális veszteség fenyőnél 20% volt, míg az eukaliptusznál csak 10%. Minél több cellulázt adtunk hozzá, annál alacsonyabb lett a viszkozitás, ami a cellulózlánc gyakoribb hasadását jelenti. Ha azonban 3 cellulázt vizs-gáltunk, az egyiknek nem volt hatása a viszko-zitásra még nagyobb koncentráció esetén sem. Következésképpen elmondható, hogy a celluláz szó nem jelentette ugyanazt, a márkanévtől függően. Endo- és exo- glükanáz-aktivitást kell specifikálni annak érdekében, hogy azonosítani lehessen a celluláz alkalmazásának következ-ményeit. Eközben a vizsgált hemicelluláz csak korlátozott tevékenységet mutatott a cellulóz- WORKING GROUP 3.
How do enzymatic treatments affect fibre
Michael Lecourt1, Pierre Nougier, Adrien Soranzo, Sandra Tapin-Lingua and Michel Petit-Conil FCBA, BP251, 38044 GRENOBLE Cedex 9, FRANCE Unrefined pulp properties showed a better bonding potential using cellulase and also a Enzymes are catalysts used worldwide, in clear increase in water retention value, reveal- large scale and for many applications. They are ing increased fibrillation and fibre hydration. mainly used in food industry and in agriculture. Besides, a higher brightness was enhanced by Recent developments in enzyme production hemicellulases treatment. Refining enhanced made it possible to produce pure monocom- differences. Depending on enzyme applied, ponent. So that, it became possible to use breaking length was increased by 25% and tear enzymes in fibres production processes.
index by 10% for similar energy consumptions.
Different enzymes were added to pulp sus- pensions in order to determine the impact on fibres characteristics, fibres structure and pulp quality. Cellulose degree of polymerisation or pulp viscosity was also considered to under- Enzymes are used in many processes. Main stand the enzyme effect on fibre ultrastruc- applications are in food industry (starch modifica- ture. Depending on the enzyme type, conse- tion, wine fermentation…), agriculture or chemis- quences were different. Softwood pulp viscos- try (chemical synthesis, fuel, bio-ethanol, …).
ity was the most affected by treatment with Nowadays, various enzymes are intro- cellulase compared to eucalyptus one. Maxi- duced or are ready to be used in pulp and mum losses were 20% and 10% for softwood paper processes. Most advanced applications and eucalyptus pulps, respectively. The more are bleaching of virgin pulps, deinking, pitch the cellulase charge, the lower the viscos- control, effluent treatment and energy savings ity, meaning the more cellulose chain cutting. in mechanical pulping.
However, between the 3 tested cellulases, The objective of this work was to study one did not affect the pulp viscosity, even the impact of various enzymes on commercial at the highest charge. As a consequence, it chemical pulps quality and fibre characteristics could be said that "cellulase" name had not the before and after refining.
same sense depending on production origin. Endo- and exo-glucanase activities should be specified in order to identify cellulase effects. Materials and methods
Cellulose chain cutting was not proportional to enzyme concentration. Meanwhile, tested Commercial bleached kraft pulps were con- hemicellulases presented only limited action sidered in this study: eucalyptus one and soft- towards cellulose chains, confirming that those wood one. Five commercial enzymes were used: enzymes were rather pure and that their action 3 cellulases, 1 mannanase and 1 xylanase. Pulps was limited towards hemicelluloses. Enzyme were treated with the different enzymes at 40°C, mobility and fibre locations available for deg- pulp pH at 5% consistency for 30 minutes in a radation played both role and impacted on slusher. Pulp quality was analysed on Rapid enzyme efficiency.
Köthen handsheets according to ISO standard. WORKING GROUP 3.
Figure 1: Automatic viscometer supplied by Rheotek (UK) Pulp intrinsic viscosity (SCAN method) was The pulp drying method did not affect pulp measured with an automatic viscometer sup- viscosity. Besides, pulp viscosity measure- plied by Rheotek (Figure 1).
ments were also unaffected by refining level. Refining was carried out at low consistency As a consequence, viscosities were assumed with a 12" single disc refiner pilot plant in order to be similar whatever drying method or refin- to reach different drainage levels.
ing level. So that, it was decided to carry out the intrinsic viscosity measurements on hand-sheets.
Effects of enzymatic treatments on pulp vis- cosity are presented in Figure 3 and Figure
Firstly, pulp viscosity was analysed on 4. Hemicellulase action was limited on pulp
eucalyptus kraft pulp at different refining lev- viscosity. As expected, those enzymes did not els and with two different drying methods affect cellulose chains, because the main target (Figure 2).
structure for hemicellulases are hemicelluloses.
If some small differences were observed, they
could be due to small amounts of cellulase that
may be contained in enzyme solution. In the
case of eucalyptus bleached kraft pulp (Figure
3
), none of differences were significant. But
some trends were identified: the more the cel-
lulase A, the lower the viscosity. Results were
different with softwood bleached kraft pulp
(Figure 4) as significant differences between
cellulase A and B were found. A clear impact
of cellulase charge was also observed with cel-
lulase A, contrary to cellulase B. Cellulase E
did not affect this property. Therefore, cellulase
reaction mechanisms were different in these 3
cases. As these 3 cellulases solutions present
a similar action, it could be concluded that other
Figure 2: Comparison of pulp viscosity measured on air- dried or sheetformer dried eucalyptus pulps mechanism was involved and needed to be WORKING GROUP 3.
Figure 3: Pulp viscosity obtained on eucalyptus bleached Figure 4: Pulp viscosity obtained on softwood bleached Kraft Kraft pulp after various enzymatic treatments pulp after various enzymatic treatments Figure 5: Breaking length of eucalyptus bleached kraft pulp Figure 6: Breaking length of eucalyptus bleached kraft pulp after enzymatic treatments before refining after enzymatic treatments and refining (50kWh/t applied) characterised. Cellulases activity and protein did not affect significantly this property. After composition seemed to be important param- refining, a strong improvement was measured eters to be considered.
and differences observed before refining were Mechanical properties, and more particu- changed (Figure 6). Hence, cellulase A at the larly breaking length, measured on eucalyptus lowest charge presented the highest breaking kraft pulp before and after refining, confirmed length. It was significantly improved compared the observed differences in enzyme efficiency to control and hemicellulases treatments, which (Figure 5 and Figure 6).
all were similar. Other cellulase treatments led Before refining, breaking length was affect- also to an improvement, but at a lower degree. ed by enzymatic treatments (Figure 5). Hence, However, cellulase E showed the lowest break- the highest improvements were obtained with ing length. This was in agreement with that was cellulase A and also mannanase treatment at observed on pulp viscosity for softwood pulp the highest concentrations. The other enzymes treated with cellulase E.
WORKING GROUP 3.
whatever the applied charge was. The last one had a very limited impact compared to control, In the enzyme treatment of kraft pulps, differ- and even an opposite one.
ent behaviours of pulp viscosity were observed As a consequence, the enzyme name was depending on enzyme.
not sufficient to characterise an enzymatic solu- For hemicellulases, their actions were rather tion and its potential efficiency. An enzyme limited. Viscosity measurements on eucalyptus presents a specific action devoted to catalyse and softwood bleached kraft pulps were not the cleavage of a given structure linkage. The significantly affected by either xylanase or man- most common way to characterise the enzyme nanase. In the case of eucalyptus kraft pulps, activity is to evaluate the amount of sugar impact on breaking length measured before or released after treating the corresponding pure after refining was rather limited, indicating that component. For example, in the case of xyla- the hemicelluloses had a lower impact on inter- nase, enzyme activity to degrade xylose can be fibre bonding.
evaluated by colorimetric method and modelled For cellulases, totally different behaviours at various pH and temperature (Figure 7).
were observed. Cellulases treatments had vari- However, commercial bleached chemical ous consequences on pulp viscosity, depending pulps are composed of different polysaccha- on their origins and treated substrate. Softwood rides, cellulose and hemicelluloses, with in kraft pulp was strongly affected: a maximum some cases a very limited amount of residual drop in viscosity of 22% was observed. Mean- lignin. So that, the expected enzyme actions while, for the same condition, eucalyptus kraft might be precised in order to determine the pulp presented a loss of 11% only. Among the 3 result to look after and to unexpected pulp considered cellulases, none of them had a simi- degradations. Cellulases and/or hemicellulases lar behaviour. Hence, one cellulase impacted could be interesting alternatives to enhance differently pulp properties, depending on con- the pulp properties and to save some electrical centration. Another one led to the same results energy during refining.
Figure 8: Dosage of xylanase activity by dosing sugar released after 1h treatment Cellulózrostok finomszerkezetének viselkedése
Tiemo Arndt, Gert Meinl, Klaus Erhard Pirnaer Str. 37, 01809 Heidenau, Germany e-mail: Arndt, Tiemo<Tiemo.Arndt@ptspaper.de A papírszilárdsá- (SSA) közötti korrelációra alkalmazott empi- got, több más para- rikus módszerrel határoztuk meg. Az MFC méter mellett, a cel- retenciót az eredeti rostháló és az SR mérése lulózrostok finom- után a dezintegrált rostháló SSA értékeinek szerkezete is befolyá- különbségéből határoztuk meg. solja. Az őrlés során rostfibrilláció történik, 182.79 m²/g hidrodinamikai felületet szá- és ez növeli a rostok mítottunk az MFC-re. Az őrölt rosthoz 5% felületét. Ez nem csak MFC hozzáadásával a cellulóz felülete 3.6 a végső papírszilárd- m²/g-ról 12.56 m²/g-ra nőtt. Az SSA-ből szár- ságot befolyásolja, maztatva, az MFC retenciót 63,5%-ra becsül- Tiemo Arndt hanem a lapképzés tük. A mért papírtulajdonságokkal kapcso- során a víztelenedési latban azt a következtetést vontuk le, hogy tulajdonságokat is. Ebben a munkában a az MFC viselkedése és hatékonysága nem mikrofibrillált cellulóz (MFC) lapképzésre és a hasonlítható össze az őrlés során keletkezett végső papírtulajdonságokra gyakorolt hatását finomanyagokkal, mert csak kisebb növeke- vizsgáltuk. MFC hozzáadása után a Schopper- dést észleltünk a látszólagos sűrűségben az Riegler érték drámai növekedését figyeltük MFC következtében. Az egyszerűsített refe- meg. Ugyanakkor a papírszilárdság is növeke- rencia rosthálózat alapján azonban a rostok dett az MFC nanoméretű tulajdonságai miatt. közti kötési szilárdságot 9 MPa-nál számí- A papírlapok letapogató elektronmikroszkópos tottuk 5% MFC adagolásakor, ami kétszer vizsgálata megmutatta, hogy az MFC a ros- annyi, mint a kiindulási anyagként használt tok közötti kapcsolódási pontokon filmszerűen aggregálódik. Nehéz azonban megérteni és megmérni ezeknek a cellulóz finomszerkeze- Az alkalmazott modell-feltételezés és a teknek a viselkedését a lapképzés során és mért papírtulajdonságok alapján azt a követ- a végső papírszerkezeten belül. Azért, hogy keztetést lehet levonni, hogy az MFC a hidro- több információt tudjunk feltárni a cellulóz génkötések számában növekedéshez vezet a finomszerkezeteinek viselkedéséről, egy fent- kontakt területeken a rostok között a magas ről lefelé történő megközelítést alkalmaztunk a SSA miatt, mert a látszólagos sűrűségre és, makro szintről a nanoszintre, a rostmorfológia, ezzel együtt, az RBA-ra szinte semmi hatással víztelenedési tulajdonságok és a Page egyen- sincs az MFC. Ennek következménye a kötési let alapján. A relatív kötési terület (RBA) és a szilárdság növekedése. Az MFC viselkedé- kötésszilárdság kiszámításához egy egysze- se azonban bizonytalan és nehezen magya- rűsített referencia rosthálózatot feltételeztünk. rázható, mert a fényszórási tulajdonságok Ennek a modellnek az alapján következtetést csökkenése az RBA növekedését jelzi, főleg lehetett levonni a hatékonyságról. A hidrodi- a látszólagos denzitás növekedéséhez kap- namikai felületet az SR és a fajlagos felület WORKING GROUP 3.
Behaviour of cellulose fine structures in
Tiemo Arndt, Gert Meinl, Klaus Erhard Pirnaer Str. 37, 01809 Heidenau, Germany e-mail: Arndt, Tiemo<Tiemo.Arndt@ptspaper.de ing sheet forming. Fines are commonly defined as the fraction that passes through a 200 mesh In this work the influence of microfibrillated screen. The largest fines particles are fibre cellulose (MFC) on sheet forming and final paper fragments and the smallest are fibrils whose properties was investigated. In order to reveal size can be below 1µm. In this work we investi- more information about the behaviour of these gated the influence of micro-fibrillated cellulose cellulose fine structures a top-down approach (MFC) as a special cellulosic fine material on from macro- to nano-scale was used based on sheet forming and final paper properties. MFC fibre morphology, dewatering properties and the is completely different to commonly known pulp Page equation. A hydrodynamic ´specific sur- fines, because of its much smaller size and face area (SSA) of 182.79 m²/g was calculated the material properties associated with it. MFC for MFC. By addition of 5% MFC to the refined was invented by Herrick and Turbak in the pulp the surface area of the pulp was increased early 1980ies through mechanical disintegra- from 3.6 m²/g to 12.56 m²/g. Derived from SSA, tion of the fibre wall down to the cellulose fibril MFC retention was estimated at 63.5%. In con- aggregates as building blocks of the fibre wall nection with the paper properties measured, it [1, 2]. Since then many patents have been
was concluded that behaviour and effectiveness granted and applications introduced on the of MFC are not comparable with those of fines basis of MFC. However, due to the high energy produced during refining because only a minor consumption for fibre wall homogenization, the increase in apparent density was observed preparation of MFC has been less attractive due to MFC. However based on the simplified in view of cost effectiveness. The main break- reference fibre network the bonding strength through for reducing the energy consumption between fibres was calculated at 9 MPa for an has been made by Lindström and co-workers addition of 5% MFC, which is twice as much as in recent years – by improving the pulp prepa- in the pulp used as starting material.
ration before final homogenization [3]. Today
MFC is one of the most interesting nano-materi-
als not only to papermaking scientists, but also
in the field of composite materials. Although MFC is also a cellulosic fine mate- The paper strength is influenced, among rial derived from fibre walls, it is completely other parameters, by the fine structure of pulp different to primary or secondary fines because fibres. Refining is the method most frequently MFC is a fibrillar network of entangled fibrils. used in papermaking to change the fine struc- The size of the fibrils varies across a wide range ture of fibres. Fibre fibrillation takes place dur- from 20-30 nm in width, but larger fibril bundles ing refining and increases the surface area of are present as well. Alince and co-workers fibres. At the same time different types of fine compared the behaviour and effects on paper structures are produced. This influences not properties of MFC, fines of high and low specific only the final paper strength but also optical surface area, and microcrystalline cellulose. properties and the dewatering properties dur- Their results indicate that the strength prop- WORKING GROUP 3.
erty improvement is much greater with MFC. A Meinl and Erhard [6]. Sheets were formed in a
different type of action was observed particu- Rapid Köthen former according to ISO 5269-2 larly with bleached kraft pulp, because the light at a consistency of 0.3%. The MFC used was scattering coefficient was almost unaffected by stirred for 10 minutes at 0.2% consistency and MFC in contrast to other fines, where increas- treated with an ultra-turrax blender for 2 min- ing light scattering coefficients indicated that a utes. MFC was added to the stock container of higher relative bonded area (RBA) was respon- the Rapid Köthen former sheet per sheet, to a sible for the improvement in strength properties pulp consistency of 0.3%. When PEI was used [4]. Due to the nano-scale level and similarity
as a retention aid, it was also added in the of MFC to other fines and fibres it is difficult to stock container after the MFC addition. Before characterize the mechanisms and effectiveness sheet forming the SR value was measured. of MFC in sheet forming. In order to reveal more The dried sheets were characterized accord- about the effectiveness and interaction of MFC ing to standard methods for light scattering with fibres a top-down approach was used, sup- coefficient S Scott bond z-strength, apparent ported by model assumption and calculation density, tearing resistance, tensile index, and methods. The bonding strength was calculated air permeability.
based on the PAGE equation; and the hydro-dynamic mass-specific surface area (SSA) of MFC was calculated as well.
The mass-specific surface area (SSA) – an empirical formula based on the SR value – was used for calculation.
A mixture of dried bleached hardwood and softwood pulps (ratio 4:1) was used as pulp source together with 2% suspension of The factor c is about 6,24 when applying micro-fibrillated cellulose (MFC) supplied by corresponding known values of SR and SSA STFI-Packforsk in Sweden. MFC was prepared from Heinemann [7, 8]. Eq. 1 is only valid if no
according to Pääkkö and co-workers [5]. In
chemical additives are used which could influ- order to support the retention of fines and MFC ence the pulp viscosity). The SSA value is addi- a retention aid based on high-molecular poly- tive. If SSA , are the specific surface ethylene imine (PEI) was used.
areas of the pulp / microfibrillated cellulose and w is the mass-weighted MFC share then the specific surface area SSA Technical methods
The dried market pulp was disintegrated in
water for 15 minutes, at 40°C and a consist-ency of 5%. The resulting pulp suspension To estimate the relative bonded area (RBA) was then refined in a pilot refiner at a consist- – a critical value for applying the PAGE equa- ency of 4%, using a specific refining energy tion – in a given sheet, one can use a regular of 65 kWh/t and a specific edge load of 0.1 fibre network reference which is made up of the Ws/m. After refining the fibre dimensions were same fibres and which has the same apparent analyzed by means of a Fiberlab 3.0 device. A density as the original fibre network. The RBA special method was used to characterize the was assumed as ratio between bonded area fibre fraction and dimensions of collapsed and (A ) and total area (A ) according to the follow- dried fibres in the fibre network according to WORKING GROUP 3.
riorated. The SR value has increased dramati-cally from 28 to 86 at 5% MFC. The addition of PEI caused MFC and fines to agglomerate on fibre surfaces, thus helping to reduce the SR The values D (diameter) and H (height) of value. At the same time, strength properties collapsed and dried fibres in the network were have been improved to the same extent. But it calculated by means of the fibre morphology is obvious that not all MFC has been retained data from FIBRELAB 3.0 according to Meinl in the paper sheet, because the PEI contain- and Erhard [6]. We have yet to calculate the dis-
ing sheets had always higher strength levels tance d (distance between neighbouring fibres than sheets containing no PEI - due to better in a layer, which equals the length and width of fines and MFC retention. The tensile index has the elementary cell) according to (Eq. 4). This increased by up to 70% , and also the Scott equation ensures that the apparent density of Bond z-strength by up to 170% in compari- the elementary cell equals the apparent density son to the reference pulp. However one can ρ of the sheet.
see that the apparent density has remained almost unaffected, indicating that the strength improvement is not due to a higher RBA as usually expected from common fines. But – by contrast – the light scattering S as indicator of The bonding strength b can now be calculat- the unbonded area has been reduced.
ed via the Page equation [9] for given values of
In order to reveal more about the mecha- mean fibre length FL, tensile index T and zero- nisms and effectiveness of MFC the SSA was span tensile index ZI. The cross sectional fibre calculated based on dewatering properties. equals D·H and the fibre perimeter P The calculation results of SSA are listed in equals 2(D+H). For the zero-span tensile index Tab. 2. It is obvious that the SSA of the whole
a value of 150 Nm/g was assumed.
pulp has been increased by MFC. At 5% MFC the SSA of the pulp is 12.6 m²/g. This value is in a range usually obtained by intense refin- ing only. This increase shows that with MFC more OH-groups are available for the forma-tion of more H-bonds between pulp fibres. Results and discussion
The SSA of the MFC has been calculated at 170.7 - 182.8 m²/g. This range is consist- The sheet properties are listed in Tab. 1.
ent with the results of other authors working As expected, pulp mat dewatering was dete- with nanofibrillar cellulose aerogels. Hoepfner Tab. 1: Sheet properties of MFC containing papers WORKING GROUP 3.
and Co-workers estimated the BET surface of MFC containing paper sheets. The results area of freeze dried MFC at 160 m²/g and by suggest that the high surface area and avail- supercritical drying in the range of 200-220 able OH-groups lead to much more H-bonds m²/g [10].
between the fibres in their contact areas. This Furthermore the influence of MFC on the can explain why the density and bulk proper- bonding strength b between fibres was cal- ties, respectively, have remained unchanged culated according to (Eq. 4). The bonding after the application of MFC.
strength of the reference pulp was calculated at 4.76MPa. At 5% MFC the calculated bond-ing strength was increased to 9MPa. As men- tioned above PEI as retention aid improves the retention of MFC. This is also reflected The high SSA of MFC leads to improved by the bonding strength, where b was calcu- interactions between fines and fibres. In line with lated at 10.62. In Fig. 1 the calculated bonding
the number of H-bonds, the bonding strength is strength has been plotted against the Scott increased. It may be concluded that the bond- Bond z-strength often used to describe the ing strength is improved not only by the greater bonding degree in paper sheets. Obviously, bonding area due to better fines retention, but there is a clear correlation between these two also by a higher number of H-bonds in the different approaches to estimating the bond- contact areas. However the behavior of MFC is ing properties. This indicates that the method ambiguous and difficult to explain, because the used for calculating the bonding strength is decrease in light scattering properties indicates also useful to describe the bonding behaviour an increase in RBA which is mostly connected to an increase in apparent density. But this was not observed here.
[1] Turbak, A. F., Snyder, F. W., Sandberg, K.R., J. Appl. Polym. Sci.: Appl. Polym. Tab. 2: Mass-specific surface area (SSA) of pulp and MFC Symp. 37 815-827 (1983) [2] Herrick, F. W., Casebier, R. L., Hamilton, J. K., Sandberg, K. R., J. Appl. Polym. Sci.: Appl. Polym. Symp. 37 797-813 (1983) [3] Lindström, T.; Ankerfors, M., Henriks- son, G., Patent Int. Publ. No.WO 2007/091942 A1 (2007) [4] Alince, B., Porubská, J., van de Ven, T.G.M., The Science of Papermaking 12th Fundamental Research Symposi-um in the Oxford and Cambridge Series, 1343-1355 (2002) [5] Pääkkö, M., Ankerfors, M., Kosonen, H., Nykänen, A., Ahola, S., Österberg, M., Ruokolainen, J., Laine, J., Larsson, T., Ikkala, O., Lindström, T., Biomacromol- Fig. 1: Calculated bonding strength in comparison to Scott Bond z-strength ecules 8 1934-1941 (2007) WORKING GROUP 3. [6] Meinl, G., Erhard, K., 9th PIRA Interna- [8] Heinemann, S. Evaluation of Specific tional Refining Conference, 22-23 Feb- Surface – History or new opportunity? ruary 2006, Vienna, Austria International Mechanical Pulping Con- [7] Heinemann, S. Beitrag zur Bewertung ference, Helsinki, 2001 der massespezifischen Oberfläche und [9] Page, D.H., TAPPI J. 52 674-681 ihres Einflusses auf das Festigkeitsver- halten von Papierfaserstoffen.
[10] Hoepfner, S., Ratke, L., Milow, B., Cel- Ph. thesis, TU Dresden, 1984.
lulose 15 121-129 (2008) temi magántanára koordinálta, együttműködve a Papír- és Nyomdaipari Egyesület (PNyME) Papír-ipari Szakosztálya elnökével, Szőke Andrással, valamint, az Egyesület ügyvezető igazgatójával, Pesti Sándorral.
A rendezvény három fő eseménye az Inté-
ző Bizottság ülése, a három Munkacsoport önálló tanácskozása és az MCS-k profiljának megfelelő 12 előadásból álló Szakszeminárium volt.
A program fontos kiegészítése volt a Buda- pesttől 75 kilométerre levő Dunapack Papír és
Csomagolóanyag Zrt dunaújvárosi papírgyá-

Lele István Vígh András rának meglátogatása. Dr. Szikla Zoltán elnök-
helyettes ismertette a magyar papíripar helyzetét
A COST (European Cooperation in the Field és ezen belül a Dunapack Zrt-ben folyó csoma- of Scientific and Technical Research) keretében golópapír-termelést és -fejlesztést. A Hamburger szervezett E54 COST ACTION 2006–2010 prog- csoport Dunaújvárosban 205 millió eurós beruhá- ramban („Papírgyártásban használt rostok
zás keretében 1.500 m/min sebességű, 7.800 mm finomszerkezetének és tulajdonságainak jel-
munkaszélességű új papírgépet helyez üzembe, lemzése új technológiákkal") 19 együttműködő
melynek évi kapacitása 350.000 t 70–150 g/m² európai ország vesz részt. csomagolópapír. A résztvevők megtekinthették az üzem működő papírgépét és az új beruházás A program fő célja egy olyan nemzetközi
fórum létrehozása, ahol lehetőség nyílik a papír- A gyárlátogatást követően Budapesten a részt- ipari rostok mikroszerkezete és a kész papír vevők baráti és szakmai kapcsolatokat erősítő makroszkópikus tulajdonságai közötti összefüg- kitűnő hangulatú közös vacsorán vettek részt.
gésekről új ismeretek szerzésére. Ezen túlme-nően különös figyelmet igényel, hogy hogyan Záró beszédében Prof. Dr. Arnis Treimanis befolyásolják a kémiai, illetve mechanikai feltárási a COST E54 Akció Intéző Bizottsága elnöke folyamatok és utánkezelések a papírgyártásra köszönetét fejezte ki a Munkacsoportok Koordi- alkalmas különböző rostok összetételét és finom- nátorainak, az előadások szerzőinek, valamint valamennyi tisztségviselőnek és Intéző Bizottsági A kutató munka három munkacsoportban
tagnak aktív tevékenységükért a Szakszeminári- (MCS) folyik. Témák:
um előkészítésében és megvalósításában. Külön – MCS1: Különböző kezelések hatása a papír- köszönet az Intéző Bizottság magyar tagjainak, ipari rostok szerkezetére és kémiai összeté- Dr. Víg Andrásnak és Lele István úrnak, továbbá Szőke András úrnak, Pesti Sándor úrnak és Dr. – MCS2: Egyedi rostok kezelése és jellemzé- Szikla Zoltán alelnök úrnak. Nagyrabecsülés és köszönet Dr. Polyánszky Éva főszerkesztő asz- – MCS3: Rostok finomszerkezetének hatása szonynak a Szakszeminárium teljes anyagának papírképző tulajdonságaikra, valamint kémi- sajtó alá rendezéséért a Papíripar c. folyóirat ai és enzimatikus reaktivitásukra.
E program keretében 2008-ban két rendez- Lele István vényre került sor, áprilisban Graz-ban és október- ben Budapesten. A hazai rendezvényt a COST E54 Intéző Bizottságába delegált magyar rész-vevők, Lele István, a Papíripari Kutatóintézet Kft Dr. Víg András K+F igazgatója és Dr. Víg András, a Budapesti Műszaki és Gazdaságtudományi Egyetem egye- The representatives of 19 European coun- Groups organised separately from each other tries cooperate in the program of E54 COST and a Workshop including 12 Scientific presen- (European Cooperation in the Field of Scientific tations in accordance with the activity of WGs. and Technical Research) ACTION 2006–2010 The Visit of Dunapack Paper and Pack-
"Characterisation of the fine structure and
aging Ltd. in Dunaújváros in distance of 75 km
properties of papermaking fibres using new
from Budapest has been significant additional part of the program. Detailed information about the present situation of the Hungarian paper The main objective of the Action is to
and pulp industry as well as about the activity generate new knowledge on the micro- and of Dunapack Paper and Packagings Ltd. has nanostructure of papermaking fibres and prop- been performed by Dr. Zoltán Szikla vice presi- erties required for the efficient and sustainable dent of the Ltd.
use of fibres in traditional, advanced and future In Dunaújváros a new paper machine (Rate: products. Furthermore specific attention should 1.500 m/min, productional width 7.800 mm.) be paid to the influence of the pulping proc- investment of 205 million EUR has been decid- esses i.e. for chemical and mechanical pulps ed by the Hamburger Group establishing a and fibre treatment on the fine structure and yearly capacity of 350.000 t corrugated paper composition of different papermaking fibres.
of 70–150g/m2.
Three working groups (WG) carry out the After getting back from the excursion a joint necessary scientific activities within the pro- dinner has been organized for the participants where the excellent atmosphere did a lot for – WG1: Structure and chemical composi- strengthening the friendly and professional tion of papermaking fibres after different relations within the international group of the types of treatments.
experts of paper and pulp production and – WG2: Treatment and characterisation of individual fibres by microsystem technolo-gies.
In closing the Management Commit- – WG3: The impact of the fine structure of tee meeting Action Chair Prof. A. Treimanis fibres on their papermaking properties and expressed his gratitude to the Working Group their chemical and enzymatic reactivity.
co-ordinators, the authors of the presentations as well as other officeholders and MC members Two meetings have been performed within for their active role in preparing and performing the program in 2008 in Graz, in April and in the workshop. In particular he thanked the local Budapest, in October.
organizers Dr. András Víg, Mr. István Lele, Mr. The Hungarian meeting has been organised András Szőke, Mr. Sándor Pesti and to vice by the local MC members: István Lele manag- president Dr. Zoltán Szikla. Special thanks go ing director of the Paper Research Institute Ltd. to Dr. Éva. Polyánszky for preparing the Work- and prof. Dr. András Víg Budapest University shop Proceedings collection in form of journal of Technology and Economics in cooperation "Papiripar" special edition.
with the Technical Association of the Hungar-ian Paper and Printing Industry represented by István Lele András Szőke Chairman of the Section of Paper Managing Director Industry and by Sándor Pesti managing director of the Society.
The three main parts of the Meeting have
Prof. Dr. András Víg been: MC meeting, meeting of the Working Technical Association of Paper and Printing Industry – Budapest pnyme@mtesz.hu – www.pnyme.hu A szerkesztésért felelős: Dr. Polyánszky Éva
Tájékoztatjuk Önöket, hogy a Papíripar további példányai hozzáfér- A szerkesztőség címe : 1027 Budapest, Fő utca 68. IV. em 416.
1 példány az egyesületben átvéve Postacím: 1371 Budapest, Pf. 433 1 példány postázva Kiadja: a Papír- és Nyomdaipari Műszaki Egyesület A korábban megjelent lapszámok – korlátozott példányokban – kap- Telefon: 457-0633 Telefon/fax: 202-0256 1 példány az egyesületben átvéve E-mail: pnyme@mtesz.hu 1 példány postázva honlap: www.pnyme.hu Külföldön terjeszti a Batthyány Kultúr-Press Kft.
Felelős kiadó: Fábián Endre főtitkár
1014 Budapest, Szentháromság tér 6.
Szedés, tördelés, nyomás: MODOK és Társa Kft., Kiskunhalas Hirdetések felvétele: a Papír- és Nyomdaipari Műszaki Egyesület Ügyvezető igazgató Modok Balázs
Terjeszti a PNYME 1027 Budapest, Fő utca 68, IV. em. 416.
Előfizethető a PNYME titkárságán, közvetlenül vagy postautalványon Telefon: 457-0633 • Telefon/fax: 202-0256 Előfizetési díj 2008. évre: 2700 Ft + 5% ÁFA
HU ISSN 0031-1448 Merry Christmas and a happy New Year Félix Navidad y próspero A o Frohe Weihnachten und ein glückliches neues Jahr Buon Natale e felice Anno Nuovo Joyeux No l et Bonne Année Prettige Kerstdagen en Gelukkig Nieuujaar Kellemes karácsonyi ünnepeket és boldog új évet kívánunk …és búcsúzik a fõsz

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Datasheet for bl21(de3) competent e. coli (c2527; lot 30)

5 Minute Transformation Protocol BL21(DE3) A shortened transformation protocol resulting in approximately 10% effi-ciency compared to the standard protocol may be suitable for applications Competent E. coli where a reduced total number of transformants is acceptable.Follow the Transformation Protocol with the following changes:1. Steps 3 and 5 are reduced to 2 minutes.

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