Comparison of the physical properties between hardwood and softwood pulps
2009 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 24, no 4, 409-414 p.Article in journal (Refereed) Published
High mechano-sorptive creep resistance, i.e., good creep resistance in environments with changing relative humidity, is one of the key requirements for linerboards. The aim of this study was to investigate the influence of pulp types and pulp properties on the mechano-sorptive creep of kraftliner. A high-yield softwood, kraftliner pulp, and four different hardwood pulps were investigated. The physical properties of laboratory sheets were evaluated, with emphasis on the mechano-sorptive creep properties.
The results showed that the density increase due to increased beating significantly improved the tensile stiffness of all pulps, while its effect on the isocyclic creep stiffness was less pronounced. The hardwood pulps showed higher tensile stiffness, better mechano-sorptive creep properties, and lower hygroexpansion than the softwood pulp at a given density. However, the softwood pulp did exhibit better tensile strength and fracture toughness properties than the hardwood pulps.
The results imply that hardwood pulps can be competitive with softwood pulps in kraftliners, provided that their tensile strength and fracture toughness properties can be improved by, for example, chemical means. Furthermore, the isocyclic creep stiffness correlates with the ratio of tensile stiffness to hygroexpansion, indicating that this ratio can be used for engineering estimates of the mechano-sorptive creep performance of paper materials.
Place, publisher, year, edition, pages
2009. Vol. 24, no 4, 409-414 p.
Birch, Dimensional stability, Eucalypt, Fracture toughness, Hygroexpansion, Linerboard, Mechano-sorptive creep, Softwood, Stiffness
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-9712DOI: 10.3183/NPPRJ-2009-24-04-p409-414ISI: 000273724200006ScopusID: 2-s2.0-76349105687OAI: oai:DiVA.org:kth-9712DiVA: diva2:127108
QC 201006292008-12-012008-12-012014-10-02Bibliographically approved