Method and apparatus of injection stretch blow molding

An injection stretch blow molding apparatus comprising a plurality of neck mold moving units for supporting and conveying the neck molds adapted to neck portions of hollow containers and preforms used to form the hollow containers;

• injection molding stations of M in number, each of said injection molding stations being adapted to receive the neck mold moving units sequentially and to injection mold the preforms at an injection molding start time staggered from any preceding injection molding start time for another of the injection molding stations by a time equal to N.times.T/M where T is an injection molding cycle time in each of the injection molding stations;
• blow molding stations of N in number (M>N.gtoreq.1), each of said blow molding stations being adapted to receive the neck mold moving units each supporting the preforms having their potential heat provided by the injection molding sequentially from the injection molding stations and to blow mold said preforms into the hollow containers;
• and ejecting stations of N in number for receiving the neck mold moving units each supporting the hollow containers sequentially from the blow molding stations and for ejecting said hollow containers out of said neck mold moving units, the neck mold moving units holding the injection molded preforms being sequentially moved from the injection molding stations to an empty blow molding station, the blow molding stations being adapted to blow mold the preforms into the hollow containers in a blow molding cycle time which is set to be within N.times.T/M, wherein the neck mold moving units are provided in a quantity at least equal to a total quantity of stations, and wherein one of the blow molding stations is provided in a first conveyance line that is parallel to, and fed by, a plurality of second conveyance lines in which the injection molding stations are provided.

An injection stretch blow molding apparatus at least comprising a plurality of neck plates for supporting and conveying the neck molds adapted to the neck portions of hollow containers and preforms used to form the hollow containers, the neck plates being conveyed through a number of stations and provided in a number at least equal to the number of stations;

• a plurality of conveyance lines for conveying the neck plates through the stations;
• two injection molding stations for alternately receiving said neck plates, each of said injection molding stations being adapted to injection mold said preforms at an injection molding start time different from that of the other injection molding station by substantially one-half of an injection molding cycle time T;
• a single blow molding station for alternately receiving the neck plates supporting said preforms with their potential heat provided by the injection molding step from said two injection molding stations, said preforms being blow molded into the hollow containers within (T/2), said neck plates traveling between said two injection molding stations and said single blow molding station on said plurality of conveyance lines;
• and an ejecting station for receiving said neck plates supporting said hollow containers from said blow molding station and for ejecting the hollow containers out of said neck molds, said ejecting station being located in an area adjacent to said two injection molding stations and at a middle position from which said neck plates are moved through said conveyance lines from said ejecting station to said two injection molding stations through an equal distance.

An injection stretch blow molding apparatus at least comprising a plurality of neck plates for supporting and conveying the neck molds adapted to the neck portions of hollow containers and preforms used to form the hollow containers;

• two injection molding stations for alternately receiving said neck plates, each of said injection molding stations being adapted to injection mold said preforms at an injection molding start time different from that of the other injection molding station by substantially one-half of an injection molding cycle time T;
• a blow molding station for alternately receiving the neck plates supporting said preforms with their potential heat provided by the injection molding step from said two injection molding stations, said preforms being blow molded into the hollow containers within (T/2);
• and an ejecting station for receiving said neck plates supporting said hollow containers from said blow molding station and for ejecting the hollow containers out of said neck molds, said ejecting station being located in an area adjacent to said two injection molding stations and at a middle position from which said neck plates are moved from said ejecting station to said two injection molding stations through an equal distance;
• a first conveyance line including two of said injection molding stations and the ejecting station;
• a second conveyance line including at least said blow molding station;
• a third conveyance line for supplying and conveying said neck plates from said first conveyance line to said second conveyance line;
• a fourth conveyance line for returning said neck plates from said second conveyance line back to said first conveyance line, said first, second, third and fourth conveyance lines defining a conveyance loop;
• a first conveyance unit reciprocatable along said third conveyance line and for feeding said neck plates from said first conveyance line to said second conveyance line;
• and a second conveyance unit reciprocatable along said fourth conveyance line and for feeding said neck plates from said second conveyance line to said first conveyance line.