Effects of injection molding parameters on pattern performance of in mold decorative product

Due to the decorative patterns of in-mould decoration (IMD) products that easily falls off and worn, the effects of injection moulding parameters on the film wear performance and the bonding strength were investigated based on the Taguchi orthogonal test method in this paper. Polyethylene terephthalate (PET) films with printed patterns were bonding with injected PC/ABS plastics substrate plates through different processing parameters. Research results show that the melt temperature has the most significant influence to the wear performance of the hardening layer and the pattern layer. However, the holding pressure dominates the bonding strength between pattern layer and substrate. With the increase of the melt temperature, the wear performance of the pattern increases significantly but the film bonding strength decreases. The abrasive resistance changes along with the processing parameters, but does not obey the same rules. It enhances significantly as the melt temperature is elevated, but increases first and then decreases as the injection time is extended, while decreases rapidly when the holding time lasts too long. The bonding strength gradually decreases with the elevated melt temperature, however, increases with the injection time. But generally the injection moulding parameters have little effect on the bonding strength. [Submitted 15 November 2018; Accepted 30 May 2019]