Multi-layer container and preform and process for obtaining same
AssigneePlastipak Packaging, Inc.
InventorWilliam A. Slat
Life of this patent
Estimating the term…
Abstract
A multi-layer preform, includes: (a) a plastic inner liner, comprised of a cylindrical walled body, which may or may not include a tapered annular shoulder portion, and a cylindrical walled neck portion extending upwardly from the body, and (b) a molded outer layer. Prior to the outer layer being molded over the plastic inner liner, at least a portion of the liner is crystallized by a heat treatment process. The molded outer layer may include a means to receive a closure device. When the preform is at an acceptable temperature range for orientation, the multi-layer preform can be blow-molded to form a multi-layer container having improved properties.
Claims36
A multi-layered plastic preform for manufacturing a blow molded container, comprising:
- a plastic inner liner having a thickness from 10 to 30 mils and having a cylindrical walled lower portion and a cylindrical walled upper portion integral with and extending upwardly from said lower portion, wherein at least a portion of said upper portion of the plastic inner liner is crystallized by a heat treatment process;
- and
- an injection molded outer layer that is continuous with substantially the entire length of the plastic inner liner,
- wherein said preform has a closed bottom and an open neck and wherein the inner liner is crystallized separately from and prior to injection molding of the outer layer.
A container blow molded from a multi-layered plastic preform, said preform comprising:
- a plastic inner liner having a thickness from 10 to 30 mils and having a cylindrical walled lower portion and a cylindrical walled upper portion integral with and extending upwardly from said lower portion, wherein at least a portion of said upper portion of the plastic inner liner is crystallized by a heat treatment process;
- and
- an injection molded outer layer that is continuous with substantially the entire length of the plastic inner liner,
- wherein said preform has a closed bottom and an open neck and wherein the inner liner is crystallized separately from and prior to injection molding of the outer layer.
The process which comprises:
- preparing a plastic inner liner having a thickness from 10 to 30 mils and having a cylindrical walled lower portion and a cylindrical walled upper portion integral with and extending upwardly from said lower portion;
- crystallizing at least a portion of the upper portion of the plastic inner liner by a heat treatment process;
- and
- forming a preform by injection molding an outer layer over the plastic inner layer subsequently to crystallization of the upper portion of the liner, with the outer layer being contiguous with substantially the entire length of the inner liner and with said preform having a closed bottom and open neck.
Dependencies are inferred from the claim text.