Influence of PLA on the mechanical properties of paper materials.
Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
The aim of the project is to produce a new type of paper with PLA that later will be converted into corrugated board. The PLA paper shall have enhanced moisture resistance and shall show less creep compared with conventional paper under a humid ambient climate.
Therefore, dynamic sheets with different amounts of PLA (0 %, 5% and 10 %) are manufactured. The sheets are made from unbleached softwood kraft pulp with two different grinding ratios and pulp from recovered paper. As well as examining the effect of PLA in paper, the influences of different grinding ratios and pulps are investigated.
After testing of dynamic sheets, larger paper quantities of recovered paper with 0 %, 5% and 10 % PLA are produced on a pilot paper machine (FEX). Afterwards those papers are pressed and heated to melt the PLA fibres in order to activate them. The results show that PLA strongly enhanced tensile strength (up to 80 %), stiffness, ductility and compression strength in dynamic sheets of unbeaten kraft and recovered paper. In beaten kraft dynamic sheets the strength improved slightly, whereas stiffness and compression strength decreased with addition of PLA. For unbeaten kraft paper mechano-sorptive creep was reduced. For paper produced on FEX PLA increased tensile strength. Tensile stiffness and compression strength increased in cross machine direction (CD). Mechano-sorptive creep was reduced under cyclic humidity conditions in CD.
Place, publisher, year, edition, pages
2015. , 60 p.
IdentifiersURN: urn:nbn:se:kth:diva-176012OAI: oai:DiVA.org:kth-176012DiVA: diva2:865281
Subject / course
Östlund, Sören, Professor