Methods and apparatus for injection molding and injection blow molding multi-layer articles, and the articles made thereby

An injection molding machine, comprising:

• a plurality of co-injection nozzles each having an associated injection cavity mold, each nozzle being adapted to receive valve means, and each having plural passages for feeding respective ones of plural polymeric materials from the nozzle into its associated injection cavity mold,
• a plurality of identical valve means one only being for each co-injection nozzle and each adapted to operate therethrough to, as to each nozzle, identically permit and prevent the flow of the respective plural polymeric materials into its associated injection cavity mold,
• drive means associated with each valve means and adapted for simultaneously and identically driving the plurality of valve means through their associated nozzle means, the drive means including moving means for moving each valve means through the co-injection nozzle with which it is associated, and
• control means connected to the moving means, for moving the moving means in a desired mode which provides in each nozzle simultaneous identical control over the flow and non-flow of the respective plural polymeric materials from each of the co-injection nozzles.

An injection molding machine for simultaneously injection molding a plurality of articles each made of a plurality of polymeric materials, comprising:

• a source of a first polymeric material;
• a source of a second polymeric material;
• a plurality of co-injection nozzles, each of said nozzles having an associated injection cavity mold;
• each of said nozzles also having a first flow channel for providing a stream of said first polymeric material to said mold and a second flow channel for providing a stream of said second polymeric material to said mold;
• a flow control device for feeding said polymeric materials from said sources to each of said nozzles and each of said associated molds, such that each of said streams of said first polymeric material flows from each nozzle into each associated mold simultaneously.