Technology and Stress Relaxation of Biaxially Oriented Polyolefin Shrink Films

摘要

In the present study the influence of the heating rate on the stability of the double bubble technological process was investigated. It was shown that increasing the heating rate decreases the stability of the process and causes the lower elongation of the films produced. The morphological transformations of linear low density polyethylene (LLDPE) film were explained using X-ray and transmission electrom microscopy (TEM) methods. The stress relaxation behavior of co-extruded LLDPE/ethylene-vinyl-acetate (EVA) film was studied using the relaxation time spectrum approach. The influence of vinyl-acetate (VA) content in EVA copolymers on the relaxation time spectrum was observed.