Method for molding polypropylene resin.

摘要

The subject matter of the invention is a method for producing a foamed article of a polypropylene resin. Said method comprises steps of: providing a pair of male and female molds (3,4) which are slidably moved at an engaged part (5) and in which a cavity clearance (t) is freely set, starting supply of a melt of a polypropylene resin (8) containing a chemical blowing agent through a resin melt conduit (7) which is provided in one of said male and female mold when said cavity clearance (t) is 1.0 mm or less, moving at least one of said male and female molds to increase said cavity clearance (t) during said supply of said polypropylene resin melt (8) so that the pressure on said resin melt in said mold cavity is adjusted in a range between 5 kg/cm<2> and 100 kg/cm<2>, forming a skin layer by applying a pressure of from 5 kg/cm<2> to 100 kg/cm<2> on said resin melt (8) as soon as said resin supply is finished, further increasing said cavity clearance (t) to form a foamed core layer and cooling the foamed article in said mold.