Prediction of micro-sized flash using micro-injection moulding process simulations

Micro-injection moulding process simulations can be important to substantially reduce experimental and quality assurance efforts [1-2]. In this study, the usage of process simulations for the prediction of the size of the flash affecting a three-dimensional polyoxymethylene (POM) micro component is discussed.

A 3D multi-scale mesh was used to discretize the geometry of the one-cavity micro mould. The venting channel was included into the model in order to simulate the flash formation as a virtual short-shot. Simulations were run with Autodesk Moldflow Insight 2017® and results validated comparing numerical results with experimental observations.

A 3D focus variation instrument was used to measure the flash on moulded parts. Four injection moulding process parameters were tested to validate the numerical model with respect to process settings variation. Flash size was generally overestimated by simulations. However, both real and numerical results agreed on the signs and magnitudes of the effects of the investigated process parameters, demonstrating that simulations are a helpful tool for process optimization in the micro-scale.