Claims
- 1. A stable moldable needled fibrous composite structure, comprising:
- a first substrate defining a base side and a face side on opposite sides thereof,
- a middle layer adjacent to said face side of said first substrate, said middle layer comprising mineral fibers of sufficiently short length to substantially preclude interlocking of said mineral fibers with other fibers of said needled structure and to provide said structure with a desired degree of flexibility, said middle layer of mineral fibers initially having lacked structural integrity before being made an integral part of said composite structure, said mineral fibers being present in a quantity sufficient to impart desired heat and sound insulating properties to said structure,
- a non-woven top layer adjacent to said middle layer and opposite said substrate relative to said middle layer, said top layer comprising organic fibers or a substantially uniform mixture of organic and inorganic fibers with the organic fibers comprising more than 10 percent of said uniform mixture, said fibers of said top layer being of sufficient average length whereby a sufficient portion of said fibers of said top layer interlock with said first substrate as a result of needling said fibers through the top layer, middle layer and first substrate to provide a substantially stable structure, said fibers of said top layer being of sufficient strength and present in sufficient quantity to provide said top layer with a substantially uniform cross-sectional area,
- said needled structure having a punch density of between about 400 to 3,000 penetrations per square inch.
- 2. The composition structure of claim 1 wherein said substrate comprises a fibrous web formed by a melt blown process.
- 3. The composite structure of claim 1 wherein said substrate comprises a fibrous web formed by a spun bonded process.
- 4. The composite structure of claim 1 wherein said substrate comprises a thermoplastic film.
- 5. The composite structure of claim 4 wherein said thermoplastic film is porous and is selected from the group consisting of polyethylene, polypropylene, and polyester.
- 6. The composite structure of claim 3 wherein said fibrous substrate comprises a material selected from the group consisting of polyethylene, polypropylene, polyester, polystyrene, nylon, mylar and combinations thereof.
- 7. The composite structure of claim 1 wherein said mineral fibers comprise rock wool.
- 8. The composite structure of claim 1 wherein said mineral fibers comprise calcium, aluminum, magnesium and silicate.
- 9. The composite structure of claim 1 wherein said mineral fibers are air blown onto said face side of said substrate.
- 10. The composite structure of claim 1 wherein said top layer fibers are cross-lapped onto said mineral fibers of said adjacent middle layer.
- 11. The composite structure of claim 1 wherein said fibers of said top layer comprise a needled batt.
- 12. The composite structure of claim 1 additionally having an effective amount of a binder applied thereto.
- 13. The composite structure of claim 12 wherein said binder is selected from the group consisting of PVC, phenolic, polystyrene, nylon, polyester and ABS.
- 14. The composite structure of claim 12 wherein said binder is sprayed on said base side of said substrate.
- 15. The composite structure of claim 12 wherein said binder is roller coated to said composite.
- 16. The composite structure of claim 12 wherein said binder is applied by saturating said composite with said binder.
- 17. The composite structure of claim 12 wherein said binder comprises a resin which requires a relatively high temperature to cure, wherein said composite structure comprises a generally symmetrical structure.
- 18. The composite structure of claim 12 wherein said middle layer additionally comprises said binder.
- 19. The composite structure of claim 18 wherein said binder is pre-mixed with said mineral fibers of said middle layer.
- 20. The composite structure of claim 1 additionally comprising at least one additional needleable substrate interposed between said middle layer and said top layer.
- 21. The composite structure of claim 1 additionally comprising a layer of glass fibers interposed between said middle layer and said top layer.
- 22. The composite structure of claim 1 additionally comprising a layer of glass fibers interposed between said middle layer and said substrate.
- 23. A method for the production of a moldable fibrous composite structure, said method comprising the steps of:
- introducing a first needleable substrate, said substrate defining a base side opposite a face side,
- introducing a middle layer comprising mineral fibers of sufficiently short length to substantially preclude interlocking of any of said mineral fibers with other fibers of said structure and to provide said structure with a desired degree of flexibility onto the face side of said first needleable substrate, said middle layer of mineral fibers initially lacking structural integrity, said mineral fibers being present in a quantity sufficient to impart desired heat and sound insulating properties to said structure,
- introducing a non-woven top layer comprising organic fibers or a substantially uniform mixture of more than ten percent organic fibers with inorganic fibers onto said middle layer whereby said middle layer is disposed between said first substrate and said top layer to form a precursor composite, said fibers of said top layer being of a sufficient average length whereby a sufficient portion of said top layer fibers interlock with said first substrate upon needling said fibers completely through the top layer, middle layer and first substrate to provide a substantially stable structure, said fibers of said top layer being of sufficient strength and present in sufficient quantity to provide said top layer with a substantially uniform cross-sectional area upon subsequent needling of said precursor composite, and
- thereafter needling said precursor composite by driving the needles completely through the top layer and middle layer and into the first substrate whereby said structure having a punch density of between about 400 to 3,000 penetrations per square inch is attained and said structure being producible on a continuous basis.
- 24. The method of claim 23 wherein said substrate comprises a fibrous web.
- 25. The method of claim 23 additionally comprising the step of forming said substrate.
- 26. The method of claim 25 wherein said substrate comprises a fibrous web and said step of forming said substrate comprises a melt blown process.
- 27. The method of claim 25 wherein said substrate comprises a fibrous web and said step of forming said substrate comprises a spun bonded process.
- 28. The method of claim 23 wherein said substrate comprises a thermoplastic film.
- 29. The method of claim 28 wherein said porous thermoplastic is selected from the group consisting of polyethylene, polypropylene, and polyester.
- 30. The method of claim 23 wherein said substrate comprises a material selected from the group consisting of polyethylene, polypropylene, polyester, polystyrene, nylon, mylar and combinations thereof.
- 31. The method of claim 23 wherein said mineral fibers comprise rock wool.
- 32. The method of claim 23 wherein said mineral fibers comprise calcium, aluminum, magnesium and silicate.
- 33. The method of claim 23 wherein said step of introducing said middle layer comprises air blowing said mineral fibers onto said face side of said substrate.
- 34. The method of claim 23 wherein said step of introducing said top layer comprises cross-lapping said top layer to said adjacent middle layer.
- 35. The method of claim 23 additionally comprising the step of pre-needling said fibers of said top layer.
- 36. The method of claim 23 additionally comprising the step of applying an effective amount of binder to said structure.
- 37. The method of claim 36 wherein said binder is selected from the group consisting of PVC, phenolic, polystyrene, nylon, polyester and ABS.
- 38. The method of claim 34 wherein said step of applying said binder comprises spraying said binder onto said base side of said substrate web.
- 39. The method of claim 36 wherein said step of applying said binder comprises roller coating said composite with said binder.
- 40. The method of claim 36 wherein said step of applying said binder comprises saturating said composite with said binder.
- 41. The method of claim 36 wherein said binder comprises a resin requiring a high temperature to cure, wherein said composite structure comprises a generally symmetrical structure.
- 42. The method of claim 36 wherein said step of applying said binder comprises the step of pre-mixing said binder with said mineral fibers of said middle layer.
- 43. The method of claim 23 wherein said step of needling said three layer composite comprises punching said three layer composite with a plurality of needles each having a plurality of small barbs in a densified arrangement.
- 44. The method of claim 23 additionally comprising the step of introducing at least one additional needleable substrate onto said middle layer prior to said introduction of said top layer to form said precursor composite.
- 45. The method of claim 23 additionally comprising the step of introducing a layer of glass fibers onto said middle layer prior to said introduction of said top layer to form said precursor composite.
- 46. The method of claim 23 additionally comprising the step of introducing a layer of glass fibers onto said substrate prior to said introduction of said middle layer thereto.
- 47. The method of claim 43 wherein the depth and spacing of the barbs on the needles are such that the barbs will pick up one or more fibers which will fill the barb, said needles penetrating said top layer, middle layer and substrate for locking the fibers of the top layer with the substrate.
- 48. The composite structure of claim 1 wherein said top layer of substantially uniform mixture of organic and inorganic fibers is comprised of at least 90 percent organic fibers.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 939,052, filed Dec. 8, 1986, and now abandoned.
US Referenced Citations (13)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
939052 |
Dec 1986 |
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