PURPOSE: To produce a hollow resin molded product formed into a flat shape as a whole and having a thick-walled part and a thin-walled part in specified arrangement relation so as to sufficiently obtain usual dimensional accuracy and quality.
CONSTITUTION: A molten resin is extruded from the variable annular opening part 16 of a resin extrusion head part 10 while the dimension of the opening width of the opening part 16 is partially adjusted to obtain a parison 50 having a pair of opposed thick-walled parts extending in an extrusion direction, an annular thick-walled part crossing the extrusion direction at a right angle and other thin-walled part. A pair of the movable stretching members 40 arranged in the vicinity of the parison 50 are respectively driven in contact with the opposed thick-walled parts to stretch the parison 50 in the direction crossing the extending direction of the opposed thick-walled parts at a right angle to further reduce the thickness of the thin-walled part and the stretched parison 50 is arranged in blow molds 30, 31 to be subjected to blow molding.
YAMANE TAKAFUMI
NAKAMORI KAZUNOBU
UCHIDA TAKEYUKI
HARA MASAO
SASAKI KEITA
NISHIKAWA KASEI KK
MITSUBISHI PETROCHEMICAL CO
MAZDA MOTOR