Gas-assisted injection molding process for producing hollow molded article

A method for producing a hollow molded article having a laminated skin material comprising steps of:

• placing a skin material between a fixed mold and a movable mold when said molds are open;
• moving said movable mold to close it towards said fixed mold;
• supplying a molten resin between said skin material and said fixed mold before the molds are closed;
• closing said movable mold to fill the resin in a cavity formed by said molds;
• inserting at least one gas-supplying pin which is provided on a surface of said fixed mold into said molten resin to form a hollow part within said resin;
• supplying pressurized gas through said gas-supplying pin before said molds are closed;
• slightly opening said molds while supplying additional pressurized gas in said resin to expand said hollow part;
• and
• opening said movable mold to remove the hollow molded article from between said molds.