Shrinkage of PE films (Betex tester)

In-house method with Betex tester Principle: A round specimen of plastic film with a diameter of 50 mm is placed on a heating plate, wetted with polyethylene glycol. The shrinkage takes place while the specimen is free "swimming" in the hot polyethylene glycol. Suitable e.g. for PE films, test parameters T = 150 ° C / t = 30 s, the shrinkage [%] is determined in machine and transversal direction. Home method with Betex device Principle: A film blank with a diameter of 50 mm is placed on a heating plate wetted with polyethylene glycol. Shrinkage takes place floating in the hot polyethylene glycol. Suitable e.g. for PE films; test parameter T = 150°C/ t = 30 s, the longitudinal and also the transverse shrinkage are determined in [%].