US5976288A
Expired / Lapsed
US
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Method of forming a molded, multi-layer structure
Assignee: Individual
•
Filing: 1997-01-10
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Granted: 1999-11-02
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Expires: 2017-01-10
Abstract
Abstract A method of forming a molded, multi-layer structure begins with a pre-laminated, multi-layer structure having a thermoplastic substrate layer and a cover layer. One or more optional layers laminated may be provided between the cover layer and substrate layer. Thermoplastic materials are selected having various physical characteristics (e.g. degrees of cross-linking) to produce a molded structure having a desired shape, rigidity, hardness/softness, and other physical properties. All of the multiple layers can be made of thermoplastic materials having the same polymers to allow the molded structure to be recycled into a reusable thermoplastic material. The pre-laminated, multi-layer structure is uniformly heated, by a method which provides heat penetration and absorption substantially throughout the multi-layer structure. During thermoforming, such as with male/female molds or vacuum molds, the thickness and rigidity of the multi-layer structure can be varied. A textured or decorative surface can be pre-formed in the cover layer(s) or formed during the thermoforming process.
Inventors
- 👤 Lars O. Ekendahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:04
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29C; B29C51/00; B29C51/14; B29C51/145; B29C59/00; B29C59/02; B29C59/026; B32B27/065; B32B27/30; B32B27/304; B32B27/32; B32B27/40; B32B5/00; B32B5/18; B32B7/00; B32B7/04; B32B7/12; B29C2791/00; B29C2791/004; B29C2791/006; B29C51/08; B29C51/082; B29C51/10; B29L; B29L2009/00; B32B2323/00; B32B2323/04; B32B2323/10; B32B2327/00; B32B2327/06; B32B2375/00; B32B2419/00; B32B2605/00; B32B2605/003
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
168 words
A method of forming a molded, multi-layer structure, said method comprising the steps of: providing a pre-laminated, multi-layer structure including at least a substrate layer, an additional layer, and a cover layers wherein said substrate layer is made of a partially cross-linked thermoplastic material, and wherein said additional layer is made of a thermoplastic material having a lower degree of cross-linking than said partially cross-linked thermoplastic material of said substrate layer; heating said pre-laminated, multi-layer structure with high output infrared radiation at an off-peak wavelength in a range of about 1-2.5 microns or 3-5 microns, for raising a temperature of said pre-laminated, multi-layer structure to a thermoforming temperature substantially homogeneously throughout said pre-laminated, multi-layer structure until said pre-laminated, multi-layer structure is in a thermoformable state; and forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure, wherein said heating causes increased cross-linking in each said substrate layer and said additional layer such that said additional layer is softer than said substrate layer in said molded, multi-layer structure.
Claim 2
Independent Claim
168 words
A method of forming a molded, multi-layer structure, said method comprising the steps of: providing a pre-laminated, multi-layer structure including at least a substrate layer, an additional layer, and a cover layers wherein said substrate layer is made of a partially cross-linked thermoplastic material, and wherein said additional layer is made of a thermoplastic material having a lower degree of cross-linking than said partially cross-linked thermoplastic material of said substrate layer; heating said pre-laminated, multi-layer structure with high output infrared radiation at an off-peak wavelength in a range of about 1-2.5 microns or 3-5 microns, for raising a temperature of said pre-laminated, multi-layer structure to a thermoforming temperature substantially homogeneously throughout said pre-laminated, multi-layer structure until said pre-laminated, multi-layer structure is in a thermoformable state; and forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure, wherein said heating causes increased cross-linking in each said substrate layer and said additional layer such that said additional layer is softer than said substrate layer in said molded, multi-layer structure.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said pre-laminated, multi-layer structure is formed by bonding said substrate layer, said additional layer, and said cover layer with an adhesive.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein said pre-laminated, multi-layer structure is formed by fusion bonding said substrate layer, said additional layer, and said cover layer.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein said pre-laminated, multi-layer structure is formed by co-extruding said substrate layer, said additional layer, and said cover layer.
Claim 6
Dependent Claim
35 words
The method of claim 1 wherein said cover layer is made of a thermoplastic material, and wherein said thermoplastic materials of said substrate layer, said additional layer, and said cover layer include the same polymers.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein said substrate layer is made of a partially cross-linked polyolefin foam.
Claim 8
Dependent Claim
30 words
The method of claim 5 wherein said substrate layer, said additional layer, and said cover layer include polymers selected from the group consisting of polyurethane, polyethylene, polypropylene, and polyvinyl chloride.
Claim 9
Dependent Claim
44 words
The method of claim 1 wherein forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure includes placing said heated pre-laminated, multi-layer structure between male and female mold members, and pressing said male and female mold members against said heated pre-laminated, multi-layer structure.
Claim 10
Dependent Claim
37 words
The method of claim 1 wherein forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure includes placing said heated pre-laminated, multi-layer structure against a vacuum mold member, and vacuum molding said heated pre-laminated, multi-layer structure.
Claim 11
Dependent Claim
32 words
The method of claim 1 wherein forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure includes forming said heated pre-laminated, multi-layer structure with at least one region of varying thickness.
Claim 12
Dependent Claim
26 words
The method of claim 1 wherein forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure includes forming at least one region of varying hardness.
Claim 13
Dependent Claim
26 words
The method of claim 1 wherein forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure includes forming a textured surface on said cover layer.
Claim 14
Dependent Claim
18 words
The method of claim 1 wherein said cover layer includes a textured surface pre-formed onto said cover layer.
Claim 15
Independent Claim
164 words
A method of forming a molded, multi-layer structure, said method comprising the steps of: providing a pre-laminated, multi-layer structure including at least first and second thermoplastic layers, wherein said first thermoplastic layer is made of a partially cross-linked thermoplastic foam, and wherein said second thermoplastic layer is made of a thermoplastic foam having a lower degree of cross-linking than said partially cross-linked thermoplastic foam of said first thermoplastic layer; subjecting said pre-laminated, multi-layer structure to high output infrared radiation at an off-peak wavelength in a range of about 1-2.5 microns or 3-5 microns, for providing heat penetration and absorption substantially uniformly throughout said pre-laminated, multi-layer structure until said pre-laminated, multi-layer structure is in a thermoformable state; and forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure, wherein said heat penetration and absorption causes increased cross-linking in each of said first and second thermoplastic layers such that said second thermoplastic layer is softer than said first thermoplastic layer in said molded, multi-layer structure.
Claim 16
Independent Claim
164 words
A method of forming a molded, multi-layer structure, said method comprising the steps of: providing a pre-laminated, multi-layer structure including at least first and second thermoplastic layers, wherein said first thermoplastic layer is made of a partially cross-linked thermoplastic foam, and wherein said second thermoplastic layer is made of a thermoplastic foam having a lower degree of cross-linking than said partially cross-linked thermoplastic foam of said first thermoplastic layer; subjecting said pre-laminated, multi-layer structure to high output infrared radiation at an off-peak wavelength in a range of about 1-2.5 microns or 3-5 microns, for providing heat penetration and absorption substantially uniformly throughout said pre-laminated, multi-layer structure until said pre-laminated, multi-layer structure is in a thermoformable state; and forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure, wherein said heat penetration and absorption causes increased cross-linking in each of said first and second thermoplastic layers such that said second thermoplastic layer is softer than said first thermoplastic layer in said molded, multi-layer structure.
Claim 17
Dependent Claim
16 words
The method of claim 14 wherein said first and second thermoplastic layers include the same polymers.
Claim 18
Dependent Claim
15 words
The method of claim 14 wherein said first and second thermoplastic layers include polyolefin foam.
Claim 19
Dependent Claim
32 words
The method of claim 14 wherein forming said heated pre-laminated, multi-layer structure into said molded, multi-layer structure includes forming said heated pre-laminated, multi-layer structure with at least one region of varying thickness.
Claim 20
Dependent Claim
27 words
The method of claim 14 wherein said pre-laminated, multi-layer structure further includes a cover layer pre-laminated over at least one of said first and second thermoplastic layers.
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