PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® FROM THE PUBLISHERS OF PAPER TEC Volume 11, Number 2, 2025
On the Origins of Out-of-Plane Auxetic Response in Paper PRATEEK VERMA, ANSELM C. GRIFFIN & MEISHA L. SHOFNER Previously, several commercially available papers were examined and an increase in thickness upon stretching in certain types was found. A mechanistic explanation for the origin of this auxetic response was also devised, utilizing earlier reports. In this article, the understanding of this mechanism is applied to examine auxeticity in lab-produced paper handsheets. Only bleached kraft wood fiber pulp is employed, with no fillers, additives, or coatings incorporated. In this way, the contribution of a small number of structural factors to any auxetic response in the handsheets can be directly examined. Key structural parameters of a nonwoven cellulose fiber network in paper—staple fiber length, bulk density, and fiber contact spacing—which are predicted to affect the magnitude and sign of Poisson’s ratio previously, are altered by using softwood and hardwood pulps with and without refining to produce a range of handsheets. It is found that longer fibers favor auxeticity while refining hampers it. Contact Details: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
Phys. Status Solidi B 2025, 2400589 https://doi.org/10.1002/pssb.202400589 Creative Commons Attribution-NonCommercial License,
The Paper Industry Technical Association (PITA) is an independent organisation which operates for the general benefit of its members – both individual and corporate – dedicated to promoting and improving the technical and scientific knowledge of those working in the UK pulp and paper industry. Formed in 1960, it serves the Industry, both manufacturers and suppliers, by providing a forum for members to meet and network; it organises visits, conferences and training seminars that cover all aspects of papermaking science. It also publishes the prestigious journal Paper Technology International ® and the PITA Annual Review , both sent free to members, and a range of other technical publications which include conference proceedings and the acclaimed Essential Guide to Aqueous Coating .
Article 9 – Auxetic Response in Paper
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