Abstract: An injection molding method characterized in that after resin charging is completed, with the screw allowed to rotate, process is shifted to the metering process, and using the back pressure in the metering process as a dwelling pressure, dwelling is performed simultaneously with the resin metering. In addition, with the back pressure required for metering set to a higher value as a primary back pressure, and using the back pressure as a dwelling pressure, dwelling is performed simultaneously with the resin metering, and after the dwelling time has elapsed, with the pressure allowed to lower so as to use as a secondary back pressure, the metering is continued to a set time. According to the above-mentioned method, as a whole, the required cycle time becomes shorter than in a conventional case where metering is started after dwelling.

Abstract: A method for reducing the occurrence of voids and areas of porosity in injection molded parts. Vents are placed within the injection mold near areas of the molded part that are prone to the occurrence of voids and areas of porosity. A porous flow regulator is placed adjacent the vents to regulate the flow of the resin near the vent. The flow regulator allows air trapped within the mold to escape through the vents during molding. Allowing air trapped within the mold to escape reduces the occurrence of voids and areas of porosity in the molded part. A porous plug extends through the flow regulator and into the vent. The porous plug prevents excess quantities of resin from flowing out of the vent, thus reducing waste and also helping to maintain the flow regulator in place.