Method for blow-molding a container having a neck-portion with internal attachment means

A method for blow-molding a thermoplastic container having a body-portion and a neck-portion provided with a dispensing orifice and internal attachment means, with such method including the steps of: (a) forming a hollow parison of thermoplastic material having an open end; (b) placing the parison within a female mold cavity having a body-forming portion and a neck-forming portion such that the open end of the parison is located within the neck-forming portion of the mold cavity; (c) inserting an expandable core pin into the open end of the parison, with such core pin including blowing means connected to a pressure source and having relieved areas formed on its exterior surfaces; (d) expanding the core pin such that the open upper end of the parison is forced against the neck-forming portion of the mold cavity and into the relieved areas on the exterior of the core pin, thereby forming the internal attachment means on the inner surface of the open end of the parison; (e) introducing pressure through the blowing means of the core pin to the interior of the parison thereby expanding the parison against the inner surfaces of the body-forming portion of the female mold cavity to form the body-portion of the thermoplastic container; (f) removing the molded thermoplastic container from the female and mold cavity; and (g) collapsing the expandable core pin and, thereafter, removing the core pin from the neck-portion of the thermoplastic container.