Injection blow molding

• US 4,818,213 A
• Filed: 10/06/1986
• Issued: 04/04/1989
• Est. Priority Date: 04/12/1982
• Status: Expired due to Fees

• Current Assignee: Siegfried S. Roy
• Original Assignee: Siegfried S. Roy
• Inventors: Roy, Siegfried S.
• Primary Examiner(s): Chiesa, Richard L.
• Application Number:
  US06/916,002
• Time in Patent Office: 911 Days
• Field of Search: 425/135, 425/150, 425/525, 425/526, 425/533, 425/537, 425/528, 425/534, 264/526, 264/528, 264/531, 264/532, 264/537, 264/538
• US Class Current: 425/533
• CPC Class Codes: B29C 2049/023 using inherent heat of the preform, i.e. 1 step blow moulding
• CPC Class Codes: B29C 2949/0715 the preform having one end closed
• CPC Class Codes: B29C 2949/073 having variable diameter
• CPC Class Codes: B29C 2949/0733 at body portion
• CPC Class Codes: B29C 2949/0773 Threads
• CPC Class Codes: B29C 2949/0811 Wall thickness
• CPC Class Codes: B29C 2949/22 at neck portion
• CPC Class Codes: B29C 2949/24 at flange portion
• CPC Class Codes: B29C 2949/26 at body portion
• CPC Class Codes: B29C 2949/28 at bottom portion
• CPC Class Codes: B29C 2949/3024 characterised by the number of components or by the manufacturing technique
• CPC Class Codes: B29C 2949/3032 having components being injected
• CPC Class Codes: B29C 33/3828 Moulds made of at least two different materials having different thermal conductivities
• CPC Class Codes: B29C 49/06 Injection blow-moulding
• CPC Class Codes: B29C 49/063 with the parison axis held in the plane of rotation
• CPC Class Codes: B29C 49/071 Preforms or parisons characterised by their configuration, e.g. geometry, dimensions or physical properties
• CPC Class Codes: B29C 49/12 Stretching rods
• CPC Class Codes: B29C 49/18 using several blowing steps B29C49/16 takes precedence
• CPC Class Codes: B29C 49/6409 Thermal conditioning of preforms B29C49/68 takes precedence
• CPC Class Codes: B29C 49/6427 Cooling of preforms
• CPC Class Codes: B29C 49/6463 : by contact heating or cooling, e.g. mandrels or cores specially adapted for heating or cooling preforms
• CPC Class Codes: B29C 49/6472 : in several stages
• CPC Class Codes: B29L 2031/716 : of the wide mouth type, i.e. the diameters of the bottle opening and its body are substantially identical

Abstract

The present invention provides a multiple platen-multiple position press or injection blow molding apparatus for use in the blow molding of containers in which a preform is molded onto a core and is moved relative to the core to space a body portion of the preform from the core when the core is in the blowing station to facilitate the temperature conditioning of the preform to achieve a desired biorientation of the thermoplastic material from which the preform is made when the preform is blow molded to form a container. The temperature conditioning may be achieved by allowing stabilization of the temperature gradient through the material of the preform with or without the assistance of a supply of gas to the preform at a desired temperature.

Claims

1. Injection blow molding apparatus for use in making blow molded hollow articles of thermoplastic material having a neck with a neck opening, comprising at least one preform core having a free end and having a portion of constant cross section adjacent its base end and an adjoining tapered portion, a preform injection molding station and a blow molding station, means for mounting the core for step-wise movement to bring said core at different times into positions presented toward the preform injection molding station and the blow molding station, and neck ring split means for the core including neck engaging elements relatively movable in a direction radially toward and away from the outside of the neck of the article being formed, and shifting means operative when the core is presented toward the blow molding station for shifting the preform on the core toward the free end of the core and thereby provide spacing between the preform and said tapered portion of the core while means operative when the preform has been shifted toward the free end of the core are urging the neck engaging elements into engagement with each other so that the neck of the preform remains in sealing contact with the constant cross-section base end portion of said core, in the position where the core is presented toward the blow molding station prior to a blow molding operation.

2. An injection blow molding press for use in making blow molded hollow articles having a neck with a neck opening, comprising at least one preform core having a free end and having a portion of constant cross section adjacent its base end and an adjoining tapered portion, a preform injection molding station and a blow molding station, means for mounting the core for stepwise movement to bring said core at different times into positions presented toward the preform injection molding station and the blow molding station, and neck ring split means for the core including neck engaging elements relative movable in a direction radially toward and away from the outside of the neck of the article being formed, characterized by means for shifting the injection molded preform on the core when the core is presented toward the blow molding station prior to the blow molding of the article, said shifting being in a direction toward the free end of the core and thereby provide spacing between the preform and said tapered portion of the core prior to blow molding, and means operative when the preform has been shifted toward the free end of the core for urging neck engaging elements into engagement with each other to maintain sealing contact of the preform against the portion of the core of constant cross section.

3. An injection blow molding press for use in making blow molded hollow articles comprising at least two preform cores having free ends extended in different directions from each other and each having a portion of constant cross section adjacent its base end and an adjoining tapered portion, a preform injection molding station and a blow molding station positioned to cooperate with cores extended in said different directions, a turret for mounting said cores, the turret being mounted for step-wise angular movement to sequentially bring said cores into registry with the preform injection molding station and the blow molding station, a neck ring split for each core positioned to cooperate with the portion thereof of constant cross section, each neck ring split being mounted on the turret with freedom for movement axially of its associated core, means for relatively shifting said turret and said injection molding and blowing stations and providing for entry of each core sequentially into an injection molding station and a blow molding station, a mounting holder for each neck ring split, each holder being shiftably mounted on the turret and providing for shifting movement of the neck ring split axially of the portion of the core of constant cross section, means providing for shifting movement of the holder for each neck ring split in a direction toward the base end of its associated core when the core is in the injection molding station, means mounted on the turret for shifting the holder for each neck ring split with respect to the turret to a position displaced toward the free end of its associated core after the turret is shifted to bring the core into registry with the blow molding station and thereby space the preform from the tapered portion of its core, means for circulating a cooling medium in contact with the surface of the preform when the preform is spaced from its core, and means operative when the preform has bene shifted toward the free end of the core for maintaining the neck ring splits in contact with each other in the blow molding station to maintain sealing contact of the preform with the portion of the core of constant cross section in the blow molding station.

4. An injection blow molding press for use in making blow molded hollow articles comprising a fixed platen against which the press clamp pressure is developed, a preform injection molding station connected with said fixed platen, a movable platen, a blow molding station mounted on said movable platen, an intermediate platen, a turret mounted on said intermediate platen with freedom for angular movement, at least two preform cores mounted on said turret and having free ends extended in opposite directions, each preform core having a portion of constant cross section adjacent its base end and an adjoining tapered portion, the turret being mounted for angular movement to sequentially bring said cores into registry with the preform injection molding station and the blow molding station, a neck ring split for each core positioned to cooperate with the portion thereof of constant cross section, each neck ring split being mounted on the turret with freedom for movement axially of its associated core, means for relatively shifting said turret with respect to said injection molding and blowing stations and providing for entry of each core sequentially into an injection molding station and a blow molding station, a mounting holder for each neck ring split, each holder being shiftably mounted on the turret and providing for shifting movement of the neck ring split axially of the portion of the core of constant cross section, means providing for shifting movement of the holder for each neck ring split in a direction toward the base end of its associated core when the core is in the injection molding station, means mounted on the turret for shifting the holder for each neck ring split with respect to the turret to a position displaced toward the free end of its associated core after the turret is shifted to bring the core into registry with the blow molding station and thereby space the preform from the tapered portion of its core, means for bringing a cooling medium into contact with the preform when the neck ring split is displaced toward the free end of the core, and means operative when the preform has bene shifted toward the free end of the core for applying pressure to the neck ring splits to maintain sealing contact of the preform with the core in the blow molding station.