Mitsui Toatsu Chemicals, Incorporated

Kureha Kagaku Kogyo Kabushiki Kaisha

Takeshi Nakadai

Yuji Sawa

Shinsuke Yoshikawa

A blow molding method for transferring and heating deformed and one-sided wall-thickness parisons in which each heated parison is expanded in conformity with the mold after being stretched or just after being heated, with the use of a conveying device provided with a number of upright pins inserted into the parisons and adapted for continuous travel within a furnace while being rotated, the inner section of each parison being irregular and/or having a varying circumferential wall-thickness the upright pins having a section, which fits an inner section of the parison, formed at the lower part thereof and including a planar portion placed into sliding contact with a guide rail provided at an outlet of the furnace in order to relatively position the parison. The improvement comprising transferring across the furnace each upright pin after the parison has been insertably mounted onto the upright pin while the rotation of the upright pin is stopped for a time, lightly holding the top of the parison by an inverted funnel type guide funnel and during the light holding, rotating a positioning piece fitted with the upper inner section of the parison so that the positioning piece moves downward to properly fit the parison, subsequently upwardly retracting the guide funnel and positioning piece to cause each parison to rotate and again to be reversely transferred across and to be heated within the heating furnace, and when each parison is moved out of the furnace, again stopping only the rotation of each upright pin so that a guide rail fixedly mounted at an outlet of the furnace at a predetermined angle may be brought into sliding contact with the planar portion formed at the lower part of the upright pin, whereby the relative positional relationship between each parison and the parison stretching device or the relative positional relationship between each parison with the mold coincide.

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Iwaki, Japan

Takeshi Nakadai