US4309380A — Process for making multilayered containers

Claim 1

Independent Claim 256 words

A process for forming a hollow multilayered thermoplastic article, comprising the steps of: (A) placing a previously formed liner comprised of a thermoplastic material over a blow slot equipped core rod having liner engaging exterior surface portions formed at least in part of a porous material having a porosity of from about 1/2 to 5 microns, said liner having an internal surface configuration which is generally conformable with said exterior surface portions, said exterior surface portions being removable from said thermoplastic material, (B) reducing the pressure within said liner equipped core rod below ambient at said porous portions and optionally at said blow slot, the interrelationship between said liner and said surface portions occupied by said porous portions and said blow slot if open being such that an intimate substantially gas free contact between said liner and said adjacent exterior surface portions is achieved, (C) maintaining a reduced pressure within said core rod while providing an injection mold adjacent said liner on said core rod, (D) injecting an injectable heated thermoplastic resin into said injection mold over said liner to form a composite preform with said liner while maintaining a reduced pressure within said core rod, (E) removing said preform on said core rod from said cavity, (F) providing a blow mold adjacent said preform while maintaining said preform in a blow-moldable state, (G) pressurizing the interior of said preform substantially through said blow slot to an extent sufficient to make portions of said preform expand against said blow mold, thereby to produce a blown container.

Claim 2

Dependent Claim 256 words

A process for forming a hollow multilayered thermoplastic article, comprising the steps of: (A) placing a previously formed liner comprised of a thermoplastic material over a blow slot equipped core rod having liner engaging exterior surface portions formed at least in part of a porous material having a porosity of from about 1/2 to 5 microns, said liner having an internal surface configuration which is generally conformable with said exterior surface portions, said exterior surface portions being removable from said thermoplastic material, (B) reducing the pressure within said liner equipped core rod below ambient at said porous portions and optionally at said blow slot, the interrelationship between said liner and said surface portions occupied by said porous portions and said blow slot if open being such that an intimate substantially gas free contact between said liner and said adjacent exterior surface portions is achieved, (C) maintaining a reduced pressure within said core rod while providing an injection mold adjacent said liner on said core rod, (D) injecting an injectable heated thermoplastic resin into said injection mold over said liner to form a composite preform with said liner while maintaining a reduced pressure within said core rod, (E) removing said preform on said core rod from said cavity, (F) providing a blow mold adjacent said preform while maintaining said preform in a blow-moldable state, (G) pressurizing the interior of said preform substantially through said blow slot to an extent sufficient to make portions of said preform expand against said blow mold, thereby to produce a blown container.

Claim 3

Dependent Claim 38 words

The process of claim 1 wherein said core rod in said step (B) additionally has said blow slot thereof open and wherein said core rod in steps (C), (D), (E), and (F) has said blow slot thereof closed.

Claim 4

Dependent Claim 20 words

The process of claim 1 wherein a plurality of such multilayered thermoplastic articles are simultaneously so formed by said steps.

Claim 5

Dependent Claim 35 words

The process of claim 3 wherein, in said liner placing, a plurality of individual liners are positioned over a set of respective individual ones of said core rods from a liner magazine and feeder assembly.

Claim 6

Dependent Claim 76 words

The process of claim 3 wherein each of said liner placing, said preform injecting, said preform pressurizing and said container separating are conducted at a separate station and four sets each of an equal number of said core rods are provided, one set being located at each such station, and each set is transferred sequentially from a preceding such station in the process sequence to a next subsequent such station in a stop and go manner.

Claim 7

Dependent Claim 16 words

The process of claim 5 wherein each such set contains from 4 to 10 core rods.

Claim 8

Dependent Claim 16 words

The process of claim 1 wherein said blow slot is mechanically opened when said pressurizing occurs.

Claim 9

Dependent Claim 26 words

The process of claim 1 wherein a liner equipped core rod is temperature conditioned for a predetermined time period prior to being subjected to said injecting.

Claim 10

Dependent Claim 18 words

The process of claim 1 wherein each of said injection mold and said blow mold are split molds.

Claim 11

Dependent Claim 15 words

The process of claim 1 wherein the sequence of said steps is automatically carried out.

Claim 12

Dependent Claim 39 words

The process of claim 1 wherein, after said pressurizing, said blown container is depressurized, and said blown container on said core rod is separated from said blow mold and said blown container is then separated from said core rod.

Claim 13

Dependent Claim 215 words

In a process for forming a hollow multilayered article comprising the steps of positioning a previously formed liner of a thermoplastic material over a core rod, said core rod having an outer surface, a hollow interior, and a blow opening communicating said hollow interior with that portion of said outer surface of said core rod over which said liner is positioned, said liner having an internal surface configuration which is generally conformable with said outer surface of said core rod over which said liner is positioned, injecting a thermoplastic resin layer over said liner, blow molding said article by pressurizing said liner with said resin layer thereon through said hollow interior and said blow opening to expand said liner and said resin layer to form a container, and removing said article from said core rod, the improvement comprising the step of evacuating the air in the space between said outer surface of said core rod and the adjacent inner surface of said liner through a porous metal section on said core rod and also optionally at said blow opening, said evacuation step occurring before said injecting step, said porous metal section having a porosity of from about 1/2 to 5 microns, thereby to achieve substantially gas free contact between said liner and said core rod.

Claim 14

Dependent Claim 215 words

In a process for forming a hollow multilayered article comprising the steps of positioning a previously formed liner of a thermoplastic material over a core rod, said core rod having an outer surface, a hollow interior, and a blow opening communicating said hollow interior with that portion of said outer surface of said core rod over which said liner is positioned, said liner having an internal surface configuration which is generally conformable with said outer surface of said core rod over which said liner is positioned, injecting a thermoplastic resin layer over said liner, blow molding said article by pressurizing said liner with said resin layer thereon through said hollow interior and said blow opening to expand said liner and said resin layer to form a container, and removing said article from said core rod, the improvement comprising the step of evacuating the air in the space between said outer surface of said core rod and the adjacent inner surface of said liner through a porous metal section on said core rod and also optionally at said blow opening, said evacuation step occurring before said injecting step, said porous metal section having a porosity of from about 1/2 to 5 microns, thereby to achieve substantially gas free contact between said liner and said core rod.

Claim 15

Dependent Claim 20 words

The process as claimed in claim 12 further characterized by said evacuating step taking place during said liner positioning step.

Claim 16

Dependent Claim 19 words

The process as claimed in claim 13 further characterized by maintaining said gas free contact during said injecting step.

Claim 17

Dependent Claim 18 words

The process as claimed in claim 12 further characterized by said core rod having a coating of polytetrafluoroethylene.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1985-01-04	1985-07-06	1986-01-05	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1989-01-04	1989-07-06	1990-01-05	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1993-01-04	1993-07-06	1994-01-05	$7700.00	Window Closed / Lapsed

Process for making multilayered containers

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