Testing and Performance Evaluation
The use of ASTM test methods for evaluating the susceptibility of polyolefin film products to the effects of heat and sunlight is a well-established practice. For many years, EPI has been testing commercial films and bags containing TDPA® additives using both accelerated laboratory methods as well as outdoor exposures. Typical data are presented in ref. 1. For example, carrier bags, made from HDPE and containing TDPA® were exposed in a QUV machine (laboratory equipment that simulates accelerated real-life conditions of elevated temperature plus UV light) as well as outdoors. The bags were totally embrittled after 144 hours in the laboratory equipment and heavily oxidized (degraded) after 2 months exposure outdoors. Unexposed bags or those containing no TDPA® but exposed were unaffected, i.e., no degradation. Another example is a packaging bag made from polypropylene. These bags containing no TDPA® or with the proprietary additive but without accelerated exposure to heat or UV light showed no changes in properties. The bags containing TDPA® showed complete embrittlement after 96 hours in the QUV apparatus, drastic degradation after 90 days outdoors, and complete fragmentation after 36 days in a lab oven at 71oC.
References
1. D. M. Wiles in Biodegradable Polymers for Industrial Applications, Ray Smith (ed.) Cambridge, Woodland Publishing (CRC Press) chapter 3, pp.57-76, 2005.