Multilayer containers and methods of manufacture

A method of making a multilayer plastic container, which includes the steps of:

• (a) feeding at least two plastic materials through associated extruders,
• (b) forming a preform having at least two layers respectively consisting of said at least two plastic materials, and
• (c) blow molding said preform into a plastic container,
• characterized in that said step (a) includes feeding inert gas through at least one of said extruders to prevent oxidation of the plastic material in said at least one extruder.

A method of making a multilayer plastic container, which includes the steps of:

• (a) feeding at least two plastic materials through associated extruders,
• (b) forming a preform having at least two layers respectively consisting of said at least two plastic materials, and
• (c) blow molding the preform into a plastic container,
• characterized in that said step (a) includes feeding barrier resin through one of said extruders and feeding inert gas through said one extruder to prevent oxidation of said barrier resin.

A method of making a multilayer plastic container, which includes the steps of:

• (a) feeding at least two plastic materials through associated extruders,
• (b) injecting the plastic materials into a mold to form a preform having at least two layers, and
• (c) blow molding said preform into a plastic container,
• characterized in that said step (a) includes feeding inert gas through at least one of said extruders to prevent oxidation of the plastic material in said at least one extruder.

A method of making a multilayer plastic container, which includes the steps of:

• (a) feeding at least two plastic materials through associated extruders,
• (b) forming a preform having at least two layers respectively consisting of said at least two plastic materials, and
• (c) blow molding said preform into a plastic container within a blow mold,
• characterized by applying heat to said blow mold independently of said preform.