Influence of High-Temperature Heat Treatment on Barrier and Functional Properties of Polyolefin-Coated Papers

In this study, the effect of heat treatment on barrier and functionality of polyolefin-coated papers was investigated. The aim was to find the optimal improvements on barrier without losing the applicability of the materials due to physical damages. The results of the study proved considerable improvement in barrier characteristics of the structures. Both water vapor and oxygen transmission rates of LDPE-coatings decreased linearly following the set-temperature until 200°C. At this point, the treatment caused a continuing decrease in oxygen transmission achieving 10 × lower transmission levels than the untreated structure, whereas moisture transport faced corresponding but lower increase. This was considered to be caused by the difference in diameter of the H₂O and O₂ molecules; the smaller water molecules are able to penetrate between spherulites, whose size increased due to higher treatment temperature followed by cooling.