Process of injection stretch blow molding hollow article having thick-walled bottom.

摘要

The present invention provides an injection stretch blow molding process which can form a hollow article having a thick-walled bottom wall by regulating the bottom region (18) of an injection molded preform (10) to a temperature lower than that of a barrel preform portion (16) at a blow molding station. In the process, a bulged portion (80) formed on the distal end of a stretching rod (70) and regulated in temperature is brought into contact with the inner bottom and adjacent side walls of the preform which correspond to the bottom region of the hollow article to be formed into an increased wall thickness, before start of a biaxially stretch blow molding step wherein the preform having a potential heat provided in the injection molding step is biaxially stretched to form the hollow article. The region of the preform contacting the bulged end portion has a temperature lower than another region of the preform non-contacting the bulged end portion.