Press molding of thermoplastic resins

A method for press molding in a thermoplastic resin comprising:

• providing an unclosed mold having upper and lower halves,
• initiating closing of said upper and lower halves of said mold,
• interrupting said mold closing,
• supplying a resin melt of said thermoplastic resin to a cavity of said unclosed mold comprising said upper and lower halves through at least one passage formed in a wall of said mold, said upper and lower halves being respectively attached to upper and lower platens of a vertically movable press such that introduction of said resin melt to said cavity is started when clearance of said cavity is not greater than 50 mm and completed when the clearance reaches a distance of (t+0.1) mm or larger when t is not less than 5.0 mm, or (t+1/2t) mm or larger when t is less than 5.0 mm and not less than 1.0 mm, or 1.5 mm or larger when t is less than 1.0 mm, "t" being the thickness of said molded article,
• pressing said resin melt in said mold by restarting the closing of said upper and lower halves of said mold, before the supplying of the resin is finished, until completion of mold closing without further interruption of said closing of said mold following completion of the supplying of said resin melt, and
• cooling the molded article in said mold.