New Test Method Assesses Bottle Barrier Faster

SIG Corpoplast in Germany (U.S. office in North Branch, N.J.) has developed a faster test method to measure the barrier performance of internal coatings for PET bottles.

SIG Corpoplast in Germany (U.S. office in North Branch, N.J.) has developed a faster test method to measure the barrier performance of internal coatings for PET bottles. The new barrier tester provides a measurement in 6 min vs. the typical 4 to 14 days with traditional methods. Bottles are exposed to a conditioned environment at 50% RH and 23 C for 60 min. The inside of the bottle is flushed with dry air, and a sensor, which seals the bottle at the same time, subsequently measures the gradual increase in water vapor inside the bottle. After about 200 sec, there is a linear increase in humidity. The increase in water vapor is measured for another 100 sec to evaluate the barrier coating. The measurements are said to be reproducible with the widely used Mocon test, an industry benchmark for barrier coatings. The quick test method is still in development but SIG Corpoplast is using it to determine the barrier performance of its plasma coating system for PET bottles, called Plasmax.