A preform is provided for blow-molding to form a container. The preform includes a finish portion for rotatably engaging a closure to seal pressurized contents within an interior of the container. The finish portion comprises a cylindrical body that begins at an opening to the interior and extends to and includes a tamper evidence ledge. A bevel at a beginning of the opening receives a plug seal of the closure. Multiple mirror polished surfaces beyond the bevel are configured to cooperate with the plug seal to seal the container. Mirror polished transition surfaces are disposed between diameter changes within the finish portion. In some embodiments, wherein the plug seal includes a sidewall profile that mates with the transition surfaces, an interior surface of the preform has a diameter that tightly compresses an end of the plug seal to contain pressurized contents within the container.

A preform is provided for blow-molding to form a container. The preform includes a finish portion for rotatably engaging a closure to seal contents within an interior of the container. The finish portion comprises a cylindrical body that begins at an opening to the interior and extends to and includes a tamper evidence ledge. A mirror polished sealing surface inside the finish portion cooperates with a plug seal of the closure to seal the container. Threads outside the finish portion engage with similar threads inside the closure. Thread starts of the threads reduce potential damage to the threads during installation of the closure. The thread starts may include a start pitch that is greater than a thread pitch of the threads. A handling valley disposed between the threads and the tamper evidence ledge facilitates air-conveying the container along a manufacturing assembly line.

A nozzle is provided for engaging with lightweight preforms for blow-molding the preforms into plastic containers without damaging the finish portion of the preforms. The nozzle includes a seal configured to engage with a stepped interior of the finish portion and enables stretching and/or blow-molding the preform into a container. The seal tightly engages a smooth surface inside the finish portion without damaging the surface or a sidewall of the finish portion. In some embodiments, the seal includes a profile shape that mates with a transitional surface comprising the stepped interior of the finish portion. The profile shape distributes the contact force of the seal over a maximal area of the transition surface so as to minimize the total pressure exerted onto the finish portion. The profile shape reduces potential cracking of a thin-walled region of the finish portion during stretching and/or blow-molding the preform to form the container.

A nozzle is provided for engaging lightweight preforms for blow-molding the preforms into plastic containers without damaging the finish portion of the preforms. The nozzle includes a cylindrical portion to be advanced longitudinally inside the finish portion of a preform. The cylindrical portion engages an interior seal with a shelf comprising a stepped interior of the finish portion or includes a tapered tip to tightly engage a transition surface of the stepped interior of the finish portion. An exterior cylinder extends over an exterior of the finish portion and engages an exterior seal with a tamper evidence ledge of the finish portion to eliminate pressure across a thin-walled region of the finish portion during forming the preform into a container. In some embodiments, the exterior cylinder comprises a shroud that counteracts outward forces on the finish portion to reduce instances of cracking of the finish portion during forming plastic containers.

A hollow article 10 is molded in a state where an inner surface of a neck portion 11 including an inner screw portion is held by an inner neck mold 52, and then, the hollow article 10 is demolded from the inner neck mold 52 by inserting an ejection rod 81 into the hollow article 10 to be engaged with an inner surface of the hollow article 10 and rotating the hollow article 10 together with the ejection rod 81.

A preform molding system is disclosed that includes a cavity half that is mountable to a stationary platen of an injection molding machine and a core half that is mountable to a moving platen of the injection molding machine. The preform molding system includes a mold stack assembly having a cavity portion and a core portion. The cavity portion is coupled to the cavity half and includes a cavity insert, and the core portion is coupled to the core half and includes a core insert, a pair of neck rings, and a stripper ring. The core insert has an undercut that defines an annular protrusion on an internal surface of a preform that is created in the mold stack assembly. The preform molding system is configured to permit in sequence, retraction of the pair of neck rings away from the core insert and ejection of the preform from the core insert via the stripper ring.

A construction that prevents liquid from dripping from a nozzle and adhering to a product when the nozzle is separated from a mouth of the product after liquid-blow molding. A preform includes a mouth, a body, and a neck support portion, and is provided with a step surface on an inner peripheral face adjacent to the neck support part. A liquid blow molding apparatus includes a nozzle that is inserted in the mouth of the preform, a pressurized liquid-supply unit that supplies pressurized liquid to the nozzle, and a sealing member that is formed in a cylinder and fits on an outer peripheral face of the nozzle abuts the step surface, in an axial direction, when the nozzle is inserted in the mouth of the preform to seal the gap between the nozzle and the inner peripheral face of the preform.

A preform molding system is disclosed that includes a cavity half that is mountable to a stationary platen of an injection molding machine and a core half that is mountable to a moving platen of the injection molding machine. The preform molding system includes a mold stack assembly having a cavity portion and a core portion. The cavity portion is coupled to the cavity half and includes a cavity insert, and the core portion is coupled to the core half and includes a core insert, a pair of neck rings, and a stripper ring. The core insert has an undercut that defines an annular protrusion on an internal surface of a preform that is created in the mold stack assembly. The preform molding system is configured to permit in sequence, retraction of the pair of neck rings away from the core insert and ejection of the preform from the core insert via the stripper ring.

A hot fill plastic container has a dome portion with a convex outer surface that defines a maximum outer diameter of the container so as to extend outwardly beyond a main body portion of the container. The generally egg-shaped dome portion enhances the crush resistance of the dome and provides a point of contact between containers when they are placed adjacent to one another. A circumferential stiffening groove may be provided near a lower end of the dome portion.

A finish portion of a preform for rotatably engaging with a closure to seal pressurized contents within an interior of a container formed from the preform. The finish portion includes a cylindrical body that begins at an opening to the interior. The cylindrical body has a base surface, threads extending from the base surface, a tamper evidence ledge, and a handling surface disposed between the threads and the tamper evidence ledge. A stepped interior includes a graduated narrowing of the cylindrical body between the base surface and the handling surface.