Dimensional accuracy investigation of injection moulded micro features

Due to the sensitive nature of applications of the micro injection moulding process, such as medical and aerospace, achieving high quality parts with high dimensional accuracy is crucial. In this work, simulation and an experimental study was performed to analyse the effect of four main parameters (melt and mould temperature, injection speed and holding pressure) on dimensional accuracy of a micro feature. Moreover, the focus was also to assess the process capability of a screwless/two plungers micro moulding machine in processing polyoximethilene (POM) and liquid crystal polymers (LCP). Results showed that mould temperature and injection speed was the most effective on dimensional accuracy respectively for POM and LCP and high settings for all the parameters improved the accuracy of the ribs. For LCP achieving process reproducibility was more difficult than POM even if the obtained dimensional errors are considerably lower.