Warpage minimisation on side arm using response surface methodology (RSM)

Abstract

Catheter manufacturing process requires the use of mould called side arm through latex dipping process. Manufacturing process of a nylon PA66 - side arm via an injection moulding often leads to undesirable warpage. This research tends to determine the optimum processing parameters that can be used for manufacturing side arms in minimizing the warpage issues. The considered processing parameters were packing pressure, packing time, cooling time, mould temperature and melt temperature. Apart from that, this research also tries to find the most significant factor affecting the warpage. The side arm model was developed via computer aided drafting (CAD) software and the whole analyses on the warpage was executed via a simulation software while the parameters concerned were optimised through response surface methodology. As a result, the optimised parameter settings are 76.57 MPa, 0.60 s, 8.30 s, 34.45 °C and 275.00 °C acquired for packing pressure, packing time, cooling time, mould temperature and melt temperature respectively. On top of that, cooling time has been found to be the most influential parameter affecting the warpage with contribution factor of 4.01 % compared to others. The warpage based on parameter settings recommended by the simulation software has also been compared with that after the optimisation. It can be concluded that the warpage after optimisation is 22.8 % reduced compared to the original recommended setting.