Loading patent…
AssigneeContinental PET Technologies, Inc.
InventorsSuppayan M. Krishnakumar, Thomas E. Nahill
Estimating the term…
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.
A laminated preform for forming blow mold articles, said preform being of the type formed by solely injection molding in a single conventional injection mold unit and including a tubular wall having inner and outer surfaces, said tubular wall in radial cross section comprising inner and outer first layers of an identical coinjected thermoplastic resin, very thin inner and outer layers of an identical coinjected gas barrier material next to and between said inner and outer first layers, and a second layer of thermoplastic resin between said barrier material layers.
A method of forming a blow molded hollow member comprising the steps of forming by injection molding in sequence in a single conventional injection mold for a preform first thermoplastic resin to form in cross section inner and outer first layers of a tubular body of a preform formed of said first thermoplastic resin, a gas barrier material to form very thin inner and outer layers of the barrier material next to and between said inner and outer first layers, and a second thermoplastic resin forming a core layer between said barrier material layers with said barrier material layers being free of heat bonds with said inner and outer first layers and said core, and with said barrier material layers being tightly compressed between said core layer and a respective one of said inner and outer first layers with each of said barrier material layers being tightly compressed between adjacent ones of said core layer and said inner and outer first layers to form compression diffusion bonds between each of said barrier layer and said core layer and the respective one of said inner and outer first layers, and blow molding the preform into a hollow member while biaxially stretching the layers and reducing the thickness of the layers with the thickness of said intermediate layer being reduced to a substantially incompressible thickness.
Dependencies are inferred from the claim text.