Estudo preliminar da etapa de resfriamento do processo de rotomoldagem via simulação computacional

Abstract

Polymers are composed of large carbon chains, whether natural or synthetic and are widely present in daily human life. In this way, understanding the manufacturing processes of these materials becomes a vital mission to guarantee the quality of the final product. The rotational molding process is one of the manufacturing processes for plastic transformers, which takes place at high temperatures and low pressure. During the cooling process, some properties of the final product are controlled, such as dimensional stability and crystallization level. Therefore, this study conducted the computational simulation of the experimental stage of a rotational molding process, intending to understand the thermal behavior inside the mold of the process. An axisymmetric model was used, in addition to a polymer model based on an artificial variation of the thermal conductivity of the air. The resulting simulation curves showed characteristic process` behavior, like a high cooling rate at the beginning, a decreased cooling rate during the material contraction period and a low cooling rate at the end of the process. The final temperature of the polymer surface presented an absolute difference of 40,32% in relation to real process. It is believed this high error is due to the mold's inner layer, which was a hightemperature source during the process.