Date of Award
12-2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Packaging Science
Committee Chair/Advisor
Duncan Darby
Committee Member
James Sternberg
Committee Member
Patrick Gerard
Abstract
The growing demand for sustainable packaging has accelerated the use of paper-based materials as alternatives to plastics. To provide barrier and functional properties, these materials are often modified with polymer coatings. While beneficial during use, such coatings can persist as contaminants during recycling, potentially disrupting fiber bonding and reducing the quality of recycled paper. This study examined the impact of extrusion-coated low-density polyethylene (LDPE) films and two aqueous dispersions (Vapor/Water-Barrier, Acrylic Film (VWAF) and Oil & Grease Barrier (OGBF)) on contaminant distribution and mechanical performance of recycled handsheets. Kraft paper coated at varying levels was repulped and formed into handsheets, which were then analyzed using particle imaging and mechanical testing. Extrusion-coated samples fragmented into large, non-uniform plastic pieces. Tensile strength decreased by up to 70%, with overall reductions in burst and tear strength compared to uncoated controls. Dispersion coatings behaved differently: contaminants were more evenly distributed, and mechanical properties showed threshold-like responses. At low coating levels, some improvements in burst and tear strength were observed, but beyond approximately 10–12 g/m², properties declined. This behavior is consistent with the percolation threshold, where a critical concentration of polymer begins to dominate interactions within the fiber matrix, destabilizing bonding and introducing greater variability. iv Overall, extrusion films were more detrimental to recycled paper performance, while dispersion coatings, though less severe, still negatively influenced tensile strength and introduced variability near threshold levels.
Recommended Citation
Guevarra, Ezekiel J., "Effect of Polymer Contaminants Sourced From Coated Paper on the Performance of the Resulting Recycled Paper" (2025). All Theses. 4621.
https://open.clemson.edu/all_theses/4621