A1 Journal article (refereed), original research

Effect of blank pre-conditioning humidity on the dimensional accuracy and rigidity of paperboard trays


Publication Details
Authors: Ovaska Sami-Seppo, Tanninen Panu, Saukkonen Esa, Backfolk Kaj
Publisher: Arbor Publishing Ab
Publication year: 2018
Language: English
Related Journal or Series Information: Nordic Pulp and Paper Research Journal
Volume number: 33
Issue number: 2
Start page: 348
End page: 357
Number of pages: 10
ISSN: 0283-2631
JUFO-Level of this publication: 1
Open Access: Not an Open Access publication

Abstract

Optimization of storage conditions is essential for successful converting of paperboard. This paper investigates the effect of blank moisture content on the dimensional accuracy and rigidity of press-formed paperboard trays. The trays were manufactured from uncoated, pigment-coated and extrusion-coated paperboards and multi-layer materials using fixed process parameters. Because of the different layer structures and coatings, the paperboards showed different hygroscopic behavior. Prior to converting trials, the bursting strength of paperboards under different moisture conditions was assessed. It was found that the moisture content has only a minor influence on bursting strength, but moisture affects blank curling tendency and dimensional accuracy of the tray. A high blank moisture content led to a loss of the dimensional stability and load-bearing capacity of trays, although based on earlier knowledge it is evident that the moisture content should be high for successful press-forming. As expected, a low blank moisture content increased the prevalence of ruptures in forming but the resulting trays were stiffer and their dimensional accuracy was better. It was suggested that the increased stiffness is related to a more efficient moisture removal during the press-forming, so that the fiber network is more effectively consolidated due to e. g. the formation of hydrogen bonds.


Last updated on 2019-13-03 at 12:00