Fiber-reinforced recycled thermoplastic composite

• US 6,271,270 B1
• Filed: 03/19/1999
• Issued: 08/07/2001
• Est. Priority Date: 04/25/1996
• Status: Expired due to Term

• Current Assignee: Georgia Composites
• Original Assignee: Georgia Composites
• Inventors: Stoll, John R., Muzzy, John D., Eckman, Douglas C., Holty, David W.
• Primary Examiner(s): Seidleck, James J.
• Assistant Examiner(s): Asinovsky, Olga
• Application Number:
  US09/272,801
• Time in Patent Office: 872 Days
• Field of Search: 521/48, 521/40.5, 521/45.5, 521/47, 521/49.8, 523/222, 428/34.7, 428/74, 428/95, 428/97, 428/287, 428/903.3, 264/37.1
• US Class Current: 521/48
• CPC Class Codes: B29B 17/0042 for shaping parts, e.g. multilayered parts with at least one layer containing regenerated plastic
• CPC Class Codes: B29C 70/003 characterised by the matrix material, e.g. material composition or physical properties
• CPC Class Codes: B29K 2105/06 containing reinforcements, fillers or inserts
• CPC Class Codes: B29K 2105/12 of short lengths, e.g. chopped filaments, staple fibres or bristles
• CPC Class Codes: B29K 2105/26 Scrap or recycled material
• CPC Class Codes: B29L 2031/7322 Carpets
• CPC Class Codes: B32B 2305/024 Honeycomb
• CPC Class Codes: B32B 2305/70 Scrap or recycled material
• CPC Class Codes: B32B 5/28 impregnated with or embedded in a plastic substance not used
• CPC Class Codes: C08J 11/06 without chemical reactions
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling
• CPC Class Codes: Y10T 428/1321 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/237 Noninterengaged fibered material encased [e.g., mat, batt, etc.]
• CPC Class Codes: Y10T 428/23979 Particular backing structure or composition
• CPC Class Codes: Y10T 428/23993 Composition of pile or adhesive
• CPC Class Codes: Y10T 428/249933 Fiber embedded in or on the surface of a natural or synthetic rubber matrix
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/31725 Of polyamide
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31931 : Polyene monomer-containing
• CPC Class Codes: Y10T 428/31938 : Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 442/67 : Multiple nonwoven fabric layers composed of the same inorganic strand or fiber material
• CPC Class Codes: Y10T 442/671 : Multiple nonwoven fabric layers composed of the same polymeric strand or fiber material

Abstract

Fiber-reinforced recycled thermoplastic composites and methods for their manufacture are presented. In a preferred embodiment, the thermoplastic composite incorporates a matrix of recycled thermoplastic and a plurality of high modulus fibers, with the recycled thermoplastic including polyethylene, polypropylene, nylon, PET and styrene-butadiene rubber, and the high modulus fibers including glass fibers, natural fibers, carbon fibers, and aramid fibers. Preferably, each of the high modulus fibers have a minimum length of approximately ½ of an inch and a modulus of approximately one million psi.

Claims

1. A thermoplastic composite, comprising:

a matrix of recycled thermoplastic comprising at least one of the group consisting of polyethylene, polypropylene, nylon, PET and styrene-butadiene rubber; and

a plurality of high modulus fibers, said high modulus fibers comprising at least one of the group consisting of glass fibers, natural fibers, carbon fibers, and aramid fibers, each of said high modulus fibers having a minimum length of approximately ½

of an inch and a minimum modulus of one million psi, wherein a positive amount up to 10 percent by weight of said recycled thermoplastic comprises a graft copolymer of maleic anhydride with polypropylene for bonding said recycled thermoplastic to said high modulus fibers.

2. The thermoplastic composite of claim 1 wherein said recycled thermoplastic is derived from carpet and said high modulus fibers comprise glass fibers in a weight percentage of about 20% to 60%.

3. The thermoplastic composite of claim 1, wherein said thermoplastic composite has a basis weight of between approximately 150 and approximately 1500 g/m².

4. The thermoplastic composite of claim 1, wherein said natural fibers comprise at least one of the group consisting of cotton, kenaf, sisal and hemp fibers.

5. The thermoplastic composite of claim 1, wherein said thermoplastic composite is a laminate with a basis weight greater than 1,500 g/m².

6. The thermoplastic composite of claim 1, wherein said thermoplastic composite has a first skin and a second skin and a core disposed therebetween, and said skins have a higher content of said high modulus fibers than said core.

7. The thermoplastic composite of claim 6, wherein the reinforcing fiber content of said core is less than approximately 20 percent by weight.

8. The thermoplastic composite of claim 6, wherein said core contains more than approximately 5 percent voids by volume.

9. The thermoplastic composite of claim 6, wherein said core is configured as a honeycomb structure.

10. The thermoplastic composite of claim 6, wherein said skins contain said high modulus fibers oriented in no greater than two principal directions.

11. The thermoplastic composite of claim 2, wherein said carpet comprises at least one of latex adhesive-based carpet and hot-melt adhesive-based carpet.