초록 ▼

This relates to laminated preforms, the method of forming such preforms and products which may be beneficially formed utilizing such preforms. Most particularly, this relates to a preform which has formed as part of the injection molding thereof two layers of barrier material which are disposed with

This relates to laminated preforms, the method of forming such preforms and products which may be beneficially formed utilizing such preforms. Most particularly, this relates to a preform which has formed as part of the injection molding thereof two layers of barrier material which are disposed within two layers of thermoplastic resin and having received therebetween a solid core of thermoplastic resin. The specific method of forming the preform permits the barrier material layers to be of a greatly reduced thickness as compared to such layer thicknesses permissible in the past, with the result that the barrier material layers in the blow molded articles are of a thickness recognized to be acceptable for the barrier function. The barrier material layers may be selectively terminated along the length of the preform so as to permit portions of the resultant blow molded article to be removed and reused. This abstract is not to be construed as limiting the claims of the application.

대표청구항 ▼

Apparatus for forming a laminated preform having inner and outer first layers, inner and outer second layers within said first layers, and an innermost third layer, said apparatus comprising a conventional preform forming injection mold unit including a mold element and a cooperating core defining a

Apparatus for forming a laminated preform having inner and outer first layers, inner and outer second layers within said first layers, and an innermost third layer, said apparatus comprising a conventional preform forming injection mold unit including a mold element and a cooperating core defining a mold cavity, at least one supply of thermoplastic resin under pressure and a separate supply of barrier material under pressure, a valve between said supplies and said mold unit, and means for actuating said valve in sequence to admit first a preselected quantity of thermoplastic resin to said mold cavity to form said first layers, then a preselected quantity of barrier material to said mold cavity to form said second layers, and finally more thermoplastic resin to said mold cavity to at least form said third layer.