Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper

Kristian Salminen, J. Cecchini, Elias Retulainen, Sanna Haavisto

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

Selective addition of papermaking chemicals to fines and long fibre fractions are known to have positive effect on strength properties of dry paper. Practically no information on the effects of selective addition on drainage and wet web properties is available. In this laboratory scale study, the effect of adding cationic starch and synthetic cationic polymer selectively to different fibre fractions was examined. TMP and bleached hardwood kraft pulp were used. The pulps were fractionated to fines and long fibre fractions. Starch was added into the long fibre fraction and synthetic cationic polymer was added into the fines fraction. After a certain time the fractions were combined and hand sheets were prepared. Tensile strength and tension holding capacity of the wet and dry paper were measured using high strain rate. The tension holding capacity (defined as the tension after a fast straining to 1% elongation followed by 0.5 seconds of relaxation) has been found to be a good indicator of wet web runnability in high speed machines. The results showed that the selective addition of chemicals to pulp fractions significantly consolidate the wet web and increase drainage rate. Pulps composed of separately chemically treated fractions gave considerably higher wet web tensile strength. The effect was greater with chemical pulp than with mechanical pulp. With chemical pulp, combining separately treated fractions gave remarkably higher residual tension than chemical addition to original pulp. With mechanical pulp no clear effect on tension holding capacity was found. Generally the results in this study indicate a high potential to improve pulp drainage and wet web runnability by means of separate chemical treatment of pulp fractions. (9 refs.)
Original languageEnglish
Title of host publicationTAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008
PublisherTAPPI Press
Pages1469-1490
Editioncd-rom
ISBN (Electronic)1-59510-172-1
Publication statusPublished - 2008
MoE publication typeA4 Article in a conference publication
EventPAPERCON 2008 - Sheraton Dallas, Dallas, United States
Duration: 4 May 20087 May 2008

Conference

ConferencePAPERCON 2008
CountryUnited States
CityDallas
Period4/05/087/05/08

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papermaking
pulp
chemical pulp
mechanical pulp
drainage
tensile strength
polymers
starch
kraft pulp
chemical treatment
hardwood
hands

Cite this

Salminen, K., Cecchini, J., Retulainen, E., & Haavisto, S. (2008). Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper. In TAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008 (cd-rom ed., pp. 1469-1490). TAPPI Press.
Salminen, Kristian ; Cecchini, J. ; Retulainen, Elias ; Haavisto, Sanna. / Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper. TAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008. cd-rom. ed. TAPPI Press, 2008. pp. 1469-1490
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abstract = "Selective addition of papermaking chemicals to fines and long fibre fractions are known to have positive effect on strength properties of dry paper. Practically no information on the effects of selective addition on drainage and wet web properties is available. In this laboratory scale study, the effect of adding cationic starch and synthetic cationic polymer selectively to different fibre fractions was examined. TMP and bleached hardwood kraft pulp were used. The pulps were fractionated to fines and long fibre fractions. Starch was added into the long fibre fraction and synthetic cationic polymer was added into the fines fraction. After a certain time the fractions were combined and hand sheets were prepared. Tensile strength and tension holding capacity of the wet and dry paper were measured using high strain rate. The tension holding capacity (defined as the tension after a fast straining to 1{\%} elongation followed by 0.5 seconds of relaxation) has been found to be a good indicator of wet web runnability in high speed machines. The results showed that the selective addition of chemicals to pulp fractions significantly consolidate the wet web and increase drainage rate. Pulps composed of separately chemically treated fractions gave considerably higher wet web tensile strength. The effect was greater with chemical pulp than with mechanical pulp. With chemical pulp, combining separately treated fractions gave remarkably higher residual tension than chemical addition to original pulp. With mechanical pulp no clear effect on tension holding capacity was found. Generally the results in this study indicate a high potential to improve pulp drainage and wet web runnability by means of separate chemical treatment of pulp fractions. (9 refs.)",
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Salminen, K, Cecchini, J, Retulainen, E & Haavisto, S 2008, Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper. in TAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008. cd-rom edn, TAPPI Press, pp. 1469-1490, PAPERCON 2008, Dallas, United States, 4/05/08.

Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper. / Salminen, Kristian; Cecchini, J.; Retulainen, Elias; Haavisto, Sanna.

TAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008. cd-rom. ed. TAPPI Press, 2008. p. 1469-1490.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

TY - GEN

T1 - Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper

AU - Salminen, Kristian

AU - Cecchini, J.

AU - Retulainen, Elias

AU - Haavisto, Sanna

PY - 2008

Y1 - 2008

N2 - Selective addition of papermaking chemicals to fines and long fibre fractions are known to have positive effect on strength properties of dry paper. Practically no information on the effects of selective addition on drainage and wet web properties is available. In this laboratory scale study, the effect of adding cationic starch and synthetic cationic polymer selectively to different fibre fractions was examined. TMP and bleached hardwood kraft pulp were used. The pulps were fractionated to fines and long fibre fractions. Starch was added into the long fibre fraction and synthetic cationic polymer was added into the fines fraction. After a certain time the fractions were combined and hand sheets were prepared. Tensile strength and tension holding capacity of the wet and dry paper were measured using high strain rate. The tension holding capacity (defined as the tension after a fast straining to 1% elongation followed by 0.5 seconds of relaxation) has been found to be a good indicator of wet web runnability in high speed machines. The results showed that the selective addition of chemicals to pulp fractions significantly consolidate the wet web and increase drainage rate. Pulps composed of separately chemically treated fractions gave considerably higher wet web tensile strength. The effect was greater with chemical pulp than with mechanical pulp. With chemical pulp, combining separately treated fractions gave remarkably higher residual tension than chemical addition to original pulp. With mechanical pulp no clear effect on tension holding capacity was found. Generally the results in this study indicate a high potential to improve pulp drainage and wet web runnability by means of separate chemical treatment of pulp fractions. (9 refs.)

AB - Selective addition of papermaking chemicals to fines and long fibre fractions are known to have positive effect on strength properties of dry paper. Practically no information on the effects of selective addition on drainage and wet web properties is available. In this laboratory scale study, the effect of adding cationic starch and synthetic cationic polymer selectively to different fibre fractions was examined. TMP and bleached hardwood kraft pulp were used. The pulps were fractionated to fines and long fibre fractions. Starch was added into the long fibre fraction and synthetic cationic polymer was added into the fines fraction. After a certain time the fractions were combined and hand sheets were prepared. Tensile strength and tension holding capacity of the wet and dry paper were measured using high strain rate. The tension holding capacity (defined as the tension after a fast straining to 1% elongation followed by 0.5 seconds of relaxation) has been found to be a good indicator of wet web runnability in high speed machines. The results showed that the selective addition of chemicals to pulp fractions significantly consolidate the wet web and increase drainage rate. Pulps composed of separately chemically treated fractions gave considerably higher wet web tensile strength. The effect was greater with chemical pulp than with mechanical pulp. With chemical pulp, combining separately treated fractions gave remarkably higher residual tension than chemical addition to original pulp. With mechanical pulp no clear effect on tension holding capacity was found. Generally the results in this study indicate a high potential to improve pulp drainage and wet web runnability by means of separate chemical treatment of pulp fractions. (9 refs.)

M3 - Conference article in proceedings

SP - 1469

EP - 1490

BT - TAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008

PB - TAPPI Press

ER -

Salminen K, Cecchini J, Retulainen E, Haavisto S. Effects of selective addition of papermaking chemicals to fines and long fibres on strength and runnability of wet paper. In TAPPI Press - Paper Conference and Trade Show, PaperCon '08. Dallas, Texas, 4 - 7 May 2008. cd-rom ed. TAPPI Press. 2008. p. 1469-1490