Optimizing process parameters in micro injection moulding considering the part weight and probability of flash formation

Abstract

This paper proposes an experimental procedure for selecting the optimal processing parameters in micro injection moulding considering two quality features: flash formation and weight of the component. According to a Central Composite Design (CCD), five process parameters (melting temperature, holding pressure, moulding temperature, injection speed, and holding time) were varied according to a Central Composite Design (CCD). Empirical regression equations were estimated based on the experimental results to determine the significant factors and the optimal processing conditions. Melting temperature, holding pressure, moulding temperature, and injection speed influence the probability of flash formation, as all these factors also increase the probability of flash formation increases. As melting temperature and holding pressure increase, the part weight increases. The selection of the optimal process parameters is performed using a utility function that maximizes the part weight penalized by the probability of flash formation. The utility function suggests selecting low values of moulding temperature, injection speed and holding time, and high melting temperature and holding pressure.