A mold for blow-molding a hollow plastic article from a hot, malleable parison is provided with means for forming smooth, nonfrayed holes in the plastic article during the blow-molding operation. The means for forming the holes are located in the walls of the mold and comprise a reciprocating punch or piercing means which when reciprocated in one direction are caused to enter the mold cavity and pierce a wall of the blown hollow plastic article. The reciprocating punch or piercing means include a cylinder means located in the wall of the mold and a piston therein. The piston is reciprocated by air actuated valves so as to drive needle-like piercing means into the cavity, and withdraw them from the cavity prior to the opening of the mold. Also provided is a method for forming a hole in the wall of a blow-molded plastic article formed in a blow-molding cavity from a hollow malleable parison and during the blow-molding operation by applying pressure internally of the parison to force the parison against the walls of the mold cavity. Thereafter, a prescribed period of time is allowed to elapse for the parison to become rigid and form an article. During this time, and prior to the time that the parison becomes rigid, a reciprocating piercing means is forced inwardly from a location external to the cavity into hole-forming engagement with the walls of the plastic article now contacting the cavity walls. This reciprocating piercing means is thereafter caused to be withdrawn, usually after the parison becomes rigid, but always before the opening of the mold.

The strength of the seal of an open end parison preform fabricated at orientation temperature is increased by forming a dependent bead within a closely adjacent longitudinal recess. In an alternate embodiment the appearance of seals is improved, and pin holes reduced by forming a dependent bead in a manner such that the longitudinal stem (web) connecting the bead flares outward adjacent a bottom wall of the article being molded.

A blow molding machine having a mold cavity, a blow needle bore opening into the cavity with a blow needle in the bore, a vacuum source for drawing blow air from a molded article and an exhaust passage extending from the blow needle bore to the source for reducing pressure within the blown article.

At least one blow-molded plastic container and one compression molded lid are simultaneously produced in a blow mold. Preferably, the method and apparatus utilize a mold capable of simultaneously receiving a pair of extruded parisons. One of the parisons is utilized to produce a pair of aligned container bodies and the other of the parisons is utilized to form a pair of aligned closures. In this manner, a container and closure combination can be manufactured having perfect color matching and can be readily recycled in its entirety. In addition, the method and apparatus according to the present invention significantly reduces tooling costs and required machine capitol.

At least one blow-molded plastic container and one compression molded lid are simultaneously produced in a blow mold. Preferably, the method and apparatus utilize a mold capable of simultaneously receiving a pair of extruded parisons. One of the parisons is utilized to produce a pair of aligned container bodies and the other of the parisons is utilized to form a pair of aligned closures. In this manner, a container and closure combination can be manufactured having perfect color matching and can be readily recycled in its entirety. In addition, the method and apparatus according to the present invention significantly reduces tooling costs and required machine capitol.