Warpage of injection moulded parts as the result of mould temperature difference

Abstract

Purpose: The purpose of the research was to explore what phenomena influence parts warpage after injection moulding by different mould temperature at the opposite walls. Design/methodology/approach: The sample bars were injected into the injection mould and the warpage was observed. The deflection was measured and material structure was observed using optical microscope. Findings: It was found that the different mould wall temperature values cause the asymmetrical polymer flow in the cross-section. It was discovered by short shots observation. As result the asymmetrical structure in the parts’ cross-section occurs. Research limitations/implications: In the future work the research of stress in the parts is recommended. This could be done by elastooptical investigation of transparent parts made from polymers like PS, ABS or PC. Practical implications: It is required to assure homogeneous mould wall temperature across the entire cavity when injection moulding parts production is made. Originality/value: This is an example of combined research that is not focused on one kind of tests only and helps to find reasons of the quality problem in polymer parts manufacturing.