Reducing Shining Surface Defects on Housing Components Through Process Optimization

Abstract

The automotive industry demands flawless components. A critical "shining surface" defect on nylon housing parts during the pressing process caused significant financial losses, with 2,494 rejected parts recorded in just two days. This research aims to identify the root causes of this defect and determine the optimal process optimization strategy to eliminate it completely. An experimental design methodology was applied on the production line to evaluate two variables: four alternative cushioning materials for the jig contact area (n=30 each) and five holding pressure levels (n=15 each). Results showed that adjusting holding pressure failed; reducing pressure eliminated the shine but created structural gaps. Conversely, modifying the jig's contact material was highly effective. Both Polyurethane shore 60A and Foam Tape achieved a 100% defect reduction rate. Ultimately, Polyurethane shore 60A is recommended for implementation due to its significantly superior long-term durability and wear resistance compared to Foam Tape.