The relationship between shrinkage and elongation of bleached softwood kraft pulp sheets

Research output: Contribution to journalArticleScientificpeer-review

2 Citations (Scopus)

Abstract

The relationship between shrinkage and elongation of hand sheets was examined. The results show that the same dimensional contraction brought about by shrinkage can be strained out in tensile testing. However, percentage-wise the elongation is greater than the shrinkage due to different reference points, and the difference increases strongly at higher shrinkage levels. Elongation of paper can be explained mainly by two factors: The shrinkage and the net elongation of paper. Here shrinkage refers to all kinds of in-plane contraction of the fiber network (drying shrinkage, in-plane-compaction and creping). The novel concept 'net elongation' was proposed in order to separate the effect of shrinkage from the total elongation of paper. Net elongation is the elongation of corresponding unshrunken paper dried under restraint. Sheets with high elongation were prepared from bleached softwood kraft pulp and the effects of shrinkage on elongation, strength and stiffness of the paper were investigated. Mechanical treatment methods of pulp fibers and chemical strength additives were applied in order to maximize the strength and elongation. In-plane compaction and creping were used to further boost shrinkage of the high basis weight (100 g/m 2) sheets up to 160 percent. Experimental elongation data confirmed the proposed theoretical relationships.

Original languageEnglish
Pages (from-to)522-533
Number of pages12
JournalNordic Pulp and Paper Research Journal
Volume33
Issue number3
DOIs
Publication statusPublished - 2018
MoE publication typeNot Eligible

Fingerprint

kraft pulp
Kraft pulp
Softwoods
softwood
shrinkage
Elongation
contraction
compaction
pulp
pulp fiber
Compaction
Fibers
Tensile testing
stiffness
hands
drying
Pulp
Drying

Keywords

  • compaction
  • creping
  • drying
  • elongation
  • shrinkage

Cite this

@article{32115aa8504c4d0381cc9ebbfe154b6f,
title = "The relationship between shrinkage and elongation of bleached softwood kraft pulp sheets",
abstract = "The relationship between shrinkage and elongation of hand sheets was examined. The results show that the same dimensional contraction brought about by shrinkage can be strained out in tensile testing. However, percentage-wise the elongation is greater than the shrinkage due to different reference points, and the difference increases strongly at higher shrinkage levels. Elongation of paper can be explained mainly by two factors: The shrinkage and the net elongation of paper. Here shrinkage refers to all kinds of in-plane contraction of the fiber network (drying shrinkage, in-plane-compaction and creping). The novel concept 'net elongation' was proposed in order to separate the effect of shrinkage from the total elongation of paper. Net elongation is the elongation of corresponding unshrunken paper dried under restraint. Sheets with high elongation were prepared from bleached softwood kraft pulp and the effects of shrinkage on elongation, strength and stiffness of the paper were investigated. Mechanical treatment methods of pulp fibers and chemical strength additives were applied in order to maximize the strength and elongation. In-plane compaction and creping were used to further boost shrinkage of the high basis weight (100 g/m 2) sheets up to 160 percent. Experimental elongation data confirmed the proposed theoretical relationships.",
keywords = "compaction, creping, drying, elongation, shrinkage",
author = "Jarmo Kouko and Elias Retulainen",
year = "2018",
doi = "10.1515/npprj-2018-3057",
language = "English",
volume = "33",
pages = "522--533",
journal = "Nordic Pulp and Paper Research Journal",
issn = "0283-2631",
publisher = "De Gruyter",
number = "3",

}

The relationship between shrinkage and elongation of bleached softwood kraft pulp sheets. / Kouko, Jarmo; Retulainen, Elias.

In: Nordic Pulp and Paper Research Journal, Vol. 33, No. 3, 2018, p. 522-533.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - The relationship between shrinkage and elongation of bleached softwood kraft pulp sheets

AU - Kouko, Jarmo

AU - Retulainen, Elias

PY - 2018

Y1 - 2018

N2 - The relationship between shrinkage and elongation of hand sheets was examined. The results show that the same dimensional contraction brought about by shrinkage can be strained out in tensile testing. However, percentage-wise the elongation is greater than the shrinkage due to different reference points, and the difference increases strongly at higher shrinkage levels. Elongation of paper can be explained mainly by two factors: The shrinkage and the net elongation of paper. Here shrinkage refers to all kinds of in-plane contraction of the fiber network (drying shrinkage, in-plane-compaction and creping). The novel concept 'net elongation' was proposed in order to separate the effect of shrinkage from the total elongation of paper. Net elongation is the elongation of corresponding unshrunken paper dried under restraint. Sheets with high elongation were prepared from bleached softwood kraft pulp and the effects of shrinkage on elongation, strength and stiffness of the paper were investigated. Mechanical treatment methods of pulp fibers and chemical strength additives were applied in order to maximize the strength and elongation. In-plane compaction and creping were used to further boost shrinkage of the high basis weight (100 g/m 2) sheets up to 160 percent. Experimental elongation data confirmed the proposed theoretical relationships.

AB - The relationship between shrinkage and elongation of hand sheets was examined. The results show that the same dimensional contraction brought about by shrinkage can be strained out in tensile testing. However, percentage-wise the elongation is greater than the shrinkage due to different reference points, and the difference increases strongly at higher shrinkage levels. Elongation of paper can be explained mainly by two factors: The shrinkage and the net elongation of paper. Here shrinkage refers to all kinds of in-plane contraction of the fiber network (drying shrinkage, in-plane-compaction and creping). The novel concept 'net elongation' was proposed in order to separate the effect of shrinkage from the total elongation of paper. Net elongation is the elongation of corresponding unshrunken paper dried under restraint. Sheets with high elongation were prepared from bleached softwood kraft pulp and the effects of shrinkage on elongation, strength and stiffness of the paper were investigated. Mechanical treatment methods of pulp fibers and chemical strength additives were applied in order to maximize the strength and elongation. In-plane compaction and creping were used to further boost shrinkage of the high basis weight (100 g/m 2) sheets up to 160 percent. Experimental elongation data confirmed the proposed theoretical relationships.

KW - compaction

KW - creping

KW - drying

KW - elongation

KW - shrinkage

UR - http://www.scopus.com/inward/record.url?scp=85052673633&partnerID=8YFLogxK

U2 - 10.1515/npprj-2018-3057

DO - 10.1515/npprj-2018-3057

M3 - Article

VL - 33

SP - 522

EP - 533

JO - Nordic Pulp and Paper Research Journal

JF - Nordic Pulp and Paper Research Journal

SN - 0283-2631

IS - 3

ER -