PURPOSE: To simultaneously perform a parison injection process and a mold closing process and to easily perform regeneration and utilization because execution is simple and a parison material and a core material are the same by performing blowing by introducing a foamable thermoplastic polymeric material suitable for bringing the wall of a thermoplastic hollow body into contact with the wall of a mold into the hollow body.
CONSTITUTION: A cylindrical parison 13 of a thermoplastic material is extruded into the space constituted of two half molds 15 from a die 6 and the bottom part of the parison is closed by two inserts 16. The foamable polymeric substance 14 in a central accumulator chamber 10 is injected into the parison. Injection is performed by rapidly and continuously operating the opening of a valve 11, the operation of a ram 9 and the closing of the valve 11. Since the parison is low in its inner pressure, the foamable polymeric substance pushes out the wall of the parison 13 toward the walls of the half molds. At this time, two half molds 15 are closed and the periphery of the parison is cut by shearing action generated by the sliding inserts 16.
FURANCHIESUKO MASHIIA
ATSUNIBARE BUETSUZORI
AURERIIO BISUKOTSUTEI
