METHOD FOR MOLDING POLYPROPYLENE RESIN

摘要

The present invention is directed to a method of producing a foamed article of a polypropylene resin. The method comprises the steps of providing a pair of male and female molds which are slidably engaged and which have a freely set cavity clearance. A polypropylene resin melt containing a chemical blowing agent is supplied to the male or female mold when the cavity clearance is 1.0 mm or less. One of the molds is moved to increase the cavity clearance while the polypropylene resin is being supplied so that the pressure on the resin melt is adjusted in a range between 5kg/cm2 and 100kg/cm2. As soon as the resin supply is finished pressure is applied to form a skin layer on the resin melt and further increasing the cavity clearance to form a foamed core layer. The foamed article is allowed to cool in the mold. The method of the present invention is suitable for preparing embossed polyvinyl chloride leather lined with a fabric.