Avaliação do uso de politereftalato de etileno (PET) pós consumo na indústria de embalagens alimentícias

Abstract

The environmental appeals and the high percentage of Poly (Ethylene Terephthalate) - PET waste, discarded in nature, often inappropriately, drive the packaging market to seekalternatives for the use of post-consumer recycled PET (PET-PCR). In order to assist in this purpose, this work evaluated the feasibility of using 100% recycled PET as a raw material in the production of food packaging. For this purpose, PET-PCR was injected ina two-stage Husky injection molding machine with a 48-cavity mold. The results were compared with those of virgin PET (PET-V), a raw material already used, in order to evaluate the influence of the resin type used on the quality and viability of the preform for application in the packaging sector. The green coloring additive was added in both formulations, with 0.04% and 0.07%, by mass for PET-V and PET-PCR, respectively, to guarantee the color required in some types of carbonated beverages. According to the results obtained, the parameters established for the PET-PCR forming process did not cause injection defects or great divergences in relation to PET-V. Through intrinsic viscosity analysis, visual inspection, colorimetry and differential scanning calorimetry (DSC), it was noticed that PET-PCR is more susceptible to degradative hydrolytic fissionreactions, as expected, since it is a resin which has a thermal history, but these reactions do not make its use unfeasible in food packaging. The gas chromatography results show that the injection process used for PET-V provided higher acetaldehyde contents, this result was attributed to the more aggressive conditions during the extrusion step and, finally, the specific migration test showed that the PET- PCR is within the limits applicable according to the Brazilian Legislation for Carbonated Drinks (ANVISA - Technical Information No. 71 of February 11, 2016). Thus, PET-PCR can be used in theproduction of food packaging since the deviations found are purely esthetic and do not interfere with its quality and applicability.