| When testing for permeation of paper products with barrier materials applied, it is important to consider edge effect or edge leakage. Using the standard cell head supplied with the test instruments, ambient room air can leak into the test chamber. Typically this doesn’t occur with polymer materials but paper products can be porous. Mounting the coated or barrier side of the paper product to the carrier gas solves this problem. Paper products that are coated on both sides or have a center barrier (paper both sides) exhibit the edge leakage phenomenon.
To solve this challenge the Edge Leakage Head was developed. The new test is designed to seal the edge of the test sample material from the ambient air. Since there is no sample exposed to room air the permeant must diffuse through the sample material, therefore giving more accurate and repeatable results. The new test head is a simple replacement for the standard head and is interchangeable. Maximum sample thickness is 50 mils. |