Pressure Driven Filling in the Injection Molding Process of Micro Structured Parts

Pressure Driven filling is an alternative method to control the filling phase of the injection moulding process. The application boundaries of this method are not well-defined yet, even though the process promises several advantages, including enhanced part quality and improved processing conditions. In this study, the Pressure Driven approach was applied with the aim to mould a microfluidic device that embeds an array of 100 micropillars. A set of process conditions was identified through the well-known Scientific Moulding method that serves as a comparison for the evaluation of the potential applicability of the Pressure Driven method. The analysis focuses on the micro replication assessment in terms of pillars average height, as well as part dimensions and relative shrinkage. With the help of in-cavity sensors, it has been possible to demonstrate that the Pressure Driven method can provide an optimal process parameter setting. More importantly, the replication of micropillars suffers the least from air trapping and uneven replication when applying the Pressure Driven method.