Methods for Evaluating New Polymers for Flexible Packaging Seal Layers, 1990 Polymers, Laminations & Coatings Conference Proceedings

Many different polyolefins are used as seal layers in flexible packaging depending on the converting. packing and end-use requirements. Typically these seal layers are generated by an extrusion coating or coextrusion process during the production of a multilayer film or sheet.- In designing new polyolefins for these sealing applications. the I resin supplier normally simulates the polymer’s performance by extrapolating a wide variety of lab tests instead of resorting to an expensive commercial field trial.

This paper discusses a number of the polymer performance evaluation techniques in use today. Simple lab heat seal testing is compared to the use of a small-scale VFFS packaging line as a method of quantifying the value of a sealing layer. The VFFS packaging tests identified performance differences between several polyolefins which were not predicted from simple lab heat seal and hot tack tests. Other test methods used to measure sealing performance and package integrity are also discussed.