Patent ID: 7153455

Claim:
A method of making a hollow blow molded article having an integral projection extending from the exterior wall thereof comprising the steps of: (a) inserting an unblown preform of thermoplastic polymer into a blow mold having a hollow article-defining blow mold cavity and movable mold segments which move toward each other from a first retracted position to a second position within said blow mold to define and form therebetween a projection extending from the exterior wall of the molded article; (b) closing said blow mold; (c) inserting a stretch rod into the interior of said preform to stretch said preform a predetermined amount; (d) injecting a first blow gas into the interior of said preform when said blow mold is closed, said movable segments are in said first retracted position, and said preform is at a temperature in the stretch temperature range thereof to conform said preform to said blow mold cavity and produce the article of desired shape; (e) exhausting said first blow gas from the interior of the article and advancing said movable mold segments within said blow mold from said first retracted position to said second position thereby compressing said first opposing surface of the interior wall portion into contact with said second opposing surface of the interior wall to bond said opposing surfaces under an elevated temperature and form an integral projection extending from the exterior wall of the blow molded article; (f) directing a second blow gas from said stretch rod onto at least a portion of an interior wall of the article, the interior wall portion having first and second opposing surfaces; (g) opening said blow mold; and (h) removing the blow molded article having the integral projection from said blow mold.