An Experimental Setup to Measure the Transient Temperature Profiles in Water Assisted Injection Molding

Abstract Water assisted injection molding technology has gradually become an important process for making hollow plastic parts, due to its light weight, relatively lower resin cost per part, faster cycle time, and its flexibility in the design and manufacture of plastic parts. Study of the temperature profiles in molded parts is of fundamental importance to a more complete understanding of many complicated phenomena. This report presents a novel experimental setup which allows the in-situ measurement of three-dimensional temperature field in the depth of molded parts throughout the molding cycles. A specific mold equipped with tubular needles for guiding embedded micro-thermocouples was designed and manufactured. Experiments were carried out on a lab developed water assisted injection-molding system, which included an injection molding machine, a water pump, a water injection pin, a water tank equipped with a temperature regulator, and a control circuit. The resin used was semi-crystalline polypropylene. ...