Reciclagem de PET via termoformagem por compressão

Abstract

The polyethylene terephthalate PET- is an engineering thermoplastic used for various purposes, particularly as packaging. It has attractive mechanical properties for the industry, which boosted its production. The increase in production has led to environmental problems due to incorrect disposal. One of the ways of minimizing these problems is to recycle, which can be chemical, energy or mechanical in nature. The most used form is mechanical, but this causes reduction in polymer properties. This is due to degradation that the PET suffers during the process, which may be caused by the presence of water (hydrolysis), oxygen and high temperatures used. The study assessed a new mechanical way to recycle PET thermoforming through compression, where the PET was cleaned, cut, dried and pressed allied with heating. The emperature and the pressure variated and, using a statistical software, it was evaluated that the best conditions bringing the best mechanical properties. Through mechanical and chemical analyzes, as Pohl method, MEV and tensile test, it was possible to perform this critical analysis. It was observed that there was a slight degradation in samples tested and it was not possible to find a relationship between pressure and temperature adhesion due to interference of the cutting process. For statistical analysis, the optimum conditions for production of products with higher maximum pressure and flow values were with a temperature of about 190 ° C and pressure above 60 MPa.