Evaluation of folding effects on coating damage, TAPPI Journal November 2024

Application: This method advances the development of coating for paperboard applications by improving the transfer of results and knowledge. Through it, results will be more reproducible and meaningful, which will build confidence in the generated knowledge.

Author: Joel Panek, Justin Bennett, William Mallory, and Swan Smith

ABSTRACT: Barrier coatings on paperboard need to maintain integrity during converting and end-use for effective barrier performance. Folding is one of the most common deformations during converting; however, factors that affect damage during folding are not well defined. This is partly because methods to fold specimens and characterize damage are not standardized and the results are generally not transferable. In this work, we describe a method to fold paper specimens precisely and reproducibly. The keys to folding include using a defined geometry and controlled deformation. Multiple methods can be used to quantify damage; in this case, we use differences in permeability as a measure of how the coating becomes more open. Damage is sensitive to the degree of compression after the initial folding. Using a shim for support provides a defined amount of compression and minimizes the sensitivity to the applied pressure.