Effects of annealing prior to stretching on strain induced crystallization of polyethylene terephthalate

Polyethylene terephthalate (PET) is widely used in packaging and fiber industries. However, despite of its strain-induced crystallization (SIC) behavior, stretching procedures sometimes lead to dimensional instabilities upon time or at intermediate temperatures (hot filling for example). One the solutions involves heating sample during a specific given temperature, generally after stretching, promote more stable microstructure without endangering texture. In this study, effect light thermal treatment before was explored. Herein, study on PET carried out using method, prior validate improvement stability uniaxial biaxial stretching. While annealing leads relaxation any pre-organization, higher apparent crystallinity better has been indeed observed dynamic mechanical analysis X-Ray scattering technique.