Neck orienting method of bottles of saturated polyester resins

Claim 1

In a method of producing a container from a parison of saturated polyester resin, a method of forming a lip portion comprising the steps of: (a) forming said parison with a neck portion of predetermined thickness and a lip portion defining an opening into said parison, said lip portion having a lesser predetermined thickness than said neck portion; (b) holding said neck portion of said parison in a conforming neck holding device to prevent deformation of said neck portion; (c) heating said lip portion to an orientable temperature; (d) inserting an orienting rod into said lip portion opening, said orienting rod having a converging tapered head at its leading end and a straight body portion, said straight body portion and the largest diameter of said tapered head being of a diameter greater than the inner diameter of said lip portion prior to insertion of said orienting rod, said largest diameter of said tapered head being smaller than the diameter of said straight body portion such that a stepped shoulder is defined therebetween, said rod being inserted into said lip portion opening until said stepped shoulder abuts said lip portion, thereby stretching said lip portion outwardly by the insertion of said head, such that said lip portion conforms to the shape of said stepped shoulder, thereby increasing the outside diameter and the inside diameter of said lip portion without affecting said neck portion.