Thermoforming of biopolymer-green polyethylene sheets

Abstract

Thermoforming is a forming technique in which petrochemical-based thermoplastics, biodegradable plastics and also plastic composites can be formed. Due to recent developments in the packaging industry, it was understood that biodegradable plastics could replace petrochemical-based engineering plastics. In this study, a biodegradable Green Polyethylene (HDPE SGF 4950, BRASKEM) was thermoformed using two different moulds. Heating temperature and time for Green PE, vacuum value, vacuum and cooling time were determined during the experimental procedure. Spherical and conical semi-finished thermoformed samples were obtained and these samples were cut in to four symmetrical pieces. Thickness measurements were achieved on some predetermined paths in quarter samples. Additionally, thickness distribution on the same paths was predicted by GEA (Geometric Element Analysis). Predicted and obtained thickness distribution results compared to each other. Finally, we have found out that GEA is not the most efficient method to obtain the thickness distribution precisely. © 2018 International Journal of Modern Manufacturing Technologies.