Experimental study of injection-compression molding of film insert molded plates

An injection-compression molding method was applied for film insert molding, where films had three-dimensional embossed patterns. An injection-compression mold was developed, and a one valve-gate hot runner system was built into the mold, in order to prevent melt backflow in the compression stage. Injection-compression molding experiments under different compression conditions, including compression stroke and compression speed, were performed, to investigate their effects on the height of embossed patterns. The compression stroke significantly affected the height of embossed patterns after film insert molding; however, the effect of compression speed on the embossed patterns was small. The main criterion for affecting the height of embossed patterns was not the maximum cavity pressure, but the integral value of cavity pressures along time. The degree of conservation of embossed patterns in injection-compression molding was significantly improved, and was more uniform along the positions, compared with that in conventional injection molding.