Enhanced quality, stregth and cost efficiency by means of layering

Research output: Contribution to journalArticleScientific

1 Citation (Scopus)

Abstract

The effect of adding thermo-mechanical pulp (TMP) in the middle layer of fine paper was studied. Bleached hardwood pulp made of birch (BH W) was stratified in top and bottom layers, while TMP was layered in the middle layer of hand sheets. The amount of TMP in the middle layer was varied from 10 to 40 percent of grammage. Chemical pulps were beaten with a Valley laboratory beater so that they had the same tensile index of dry paper as that of TMP. In addition to standard paper, technical properties, tensile and relaxation properties of dry and wet paper at high strain rate were studied. Decrease in brightness when replacing part of chemical pulp with TMP was evaluated for the layered structure. In addition, a new method based on Kubelka & Munk equations was developed to characterize the success of stratifying. Layering of TMP in the middle enhanced surface smoothness significantly compared to trials points, where pulps were mixed and homogenous. Adding of 40% of TMP pulp in the middle layer had no effect on surface properties of hand sheets. Addition ofTMP increased the bulk of uncalendered hand sheets significantly. Increase in TMP or stratifying the pulps had no effect on the tensile properties of dry paper. Tensile strength and residual tension, i.e. tension holding capacity of wet web, increased significantly when increasing TMP in furnish. Mixing TMP in pulps instead of stratifying resulted in higher tensile and residual tension values for wet samples. A theoretical study showed that addition of TMP decreases brightness significantly also with layered structure.
Original languageEnglish
Pages (from-to)242-245
JournalPaperi ja puu
Volume89
Issue number4
Publication statusPublished - 2007
MoE publication typeB1 Article in a scientific magazine

Fingerprint

mechanical pulp
Thermomechanical pulp
cost
Costs
Pulp
pulp
chemical pulp
Chemical pulp
hands
Tensile properties
Luminance
Hardwoods
tensile strength
Betula
hardwood
Surface properties
Strain rate

Keywords

  • Relaxation
  • Residual tension
  • Runnability
  • Stratifying
  • Strength
  • Wet paper

Cite this

@article{df761f862c0e4ed9ab1adbf76c03bf28,
title = "Enhanced quality, stregth and cost efficiency by means of layering",
abstract = "The effect of adding thermo-mechanical pulp (TMP) in the middle layer of fine paper was studied. Bleached hardwood pulp made of birch (BH W) was stratified in top and bottom layers, while TMP was layered in the middle layer of hand sheets. The amount of TMP in the middle layer was varied from 10 to 40 percent of grammage. Chemical pulps were beaten with a Valley laboratory beater so that they had the same tensile index of dry paper as that of TMP. In addition to standard paper, technical properties, tensile and relaxation properties of dry and wet paper at high strain rate were studied. Decrease in brightness when replacing part of chemical pulp with TMP was evaluated for the layered structure. In addition, a new method based on Kubelka & Munk equations was developed to characterize the success of stratifying. Layering of TMP in the middle enhanced surface smoothness significantly compared to trials points, where pulps were mixed and homogenous. Adding of 40{\%} of TMP pulp in the middle layer had no effect on surface properties of hand sheets. Addition ofTMP increased the bulk of uncalendered hand sheets significantly. Increase in TMP or stratifying the pulps had no effect on the tensile properties of dry paper. Tensile strength and residual tension, i.e. tension holding capacity of wet web, increased significantly when increasing TMP in furnish. Mixing TMP in pulps instead of stratifying resulted in higher tensile and residual tension values for wet samples. A theoretical study showed that addition of TMP decreases brightness significantly also with layered structure.",
keywords = "Relaxation, Residual tension, Runnability, Stratifying, Strength, Wet paper",
author = "Antti Oksanen and Kristian Salminen and Jarmo Kouko",
year = "2007",
language = "English",
volume = "89",
pages = "242--245",
journal = "Paperi ja puu",
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}

Enhanced quality, stregth and cost efficiency by means of layering. / Oksanen, Antti; Salminen, Kristian; Kouko, Jarmo.

In: Paperi ja puu, Vol. 89, No. 4, 2007, p. 242-245.

Research output: Contribution to journalArticleScientific

TY - JOUR

T1 - Enhanced quality, stregth and cost efficiency by means of layering

AU - Oksanen, Antti

AU - Salminen, Kristian

AU - Kouko, Jarmo

PY - 2007

Y1 - 2007

N2 - The effect of adding thermo-mechanical pulp (TMP) in the middle layer of fine paper was studied. Bleached hardwood pulp made of birch (BH W) was stratified in top and bottom layers, while TMP was layered in the middle layer of hand sheets. The amount of TMP in the middle layer was varied from 10 to 40 percent of grammage. Chemical pulps were beaten with a Valley laboratory beater so that they had the same tensile index of dry paper as that of TMP. In addition to standard paper, technical properties, tensile and relaxation properties of dry and wet paper at high strain rate were studied. Decrease in brightness when replacing part of chemical pulp with TMP was evaluated for the layered structure. In addition, a new method based on Kubelka & Munk equations was developed to characterize the success of stratifying. Layering of TMP in the middle enhanced surface smoothness significantly compared to trials points, where pulps were mixed and homogenous. Adding of 40% of TMP pulp in the middle layer had no effect on surface properties of hand sheets. Addition ofTMP increased the bulk of uncalendered hand sheets significantly. Increase in TMP or stratifying the pulps had no effect on the tensile properties of dry paper. Tensile strength and residual tension, i.e. tension holding capacity of wet web, increased significantly when increasing TMP in furnish. Mixing TMP in pulps instead of stratifying resulted in higher tensile and residual tension values for wet samples. A theoretical study showed that addition of TMP decreases brightness significantly also with layered structure.

AB - The effect of adding thermo-mechanical pulp (TMP) in the middle layer of fine paper was studied. Bleached hardwood pulp made of birch (BH W) was stratified in top and bottom layers, while TMP was layered in the middle layer of hand sheets. The amount of TMP in the middle layer was varied from 10 to 40 percent of grammage. Chemical pulps were beaten with a Valley laboratory beater so that they had the same tensile index of dry paper as that of TMP. In addition to standard paper, technical properties, tensile and relaxation properties of dry and wet paper at high strain rate were studied. Decrease in brightness when replacing part of chemical pulp with TMP was evaluated for the layered structure. In addition, a new method based on Kubelka & Munk equations was developed to characterize the success of stratifying. Layering of TMP in the middle enhanced surface smoothness significantly compared to trials points, where pulps were mixed and homogenous. Adding of 40% of TMP pulp in the middle layer had no effect on surface properties of hand sheets. Addition ofTMP increased the bulk of uncalendered hand sheets significantly. Increase in TMP or stratifying the pulps had no effect on the tensile properties of dry paper. Tensile strength and residual tension, i.e. tension holding capacity of wet web, increased significantly when increasing TMP in furnish. Mixing TMP in pulps instead of stratifying resulted in higher tensile and residual tension values for wet samples. A theoretical study showed that addition of TMP decreases brightness significantly also with layered structure.

KW - Relaxation

KW - Residual tension

KW - Runnability

KW - Stratifying

KW - Strength

KW - Wet paper

M3 - Article

VL - 89

SP - 242

EP - 245

JO - Paperi ja puu

JF - Paperi ja puu

SN - 0031-1243

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ER -