Foam barrier heat shield

• US 20040247857A1
• Filed: 03/23/2004
• Published: 12/09/2004
• Est. Priority Date: 06/03/2003
• Status: Active Grant

• Current Assignee: Intellectual Property Holdings LLC
• Original Assignee: Intellectual Property Holdings LLC
• Inventors: McDonel, Bradley D., Churby, Scott A., Schroeder, Jeffrey J.
• Granted Patent: US 7,585,559 B2
• Time in Patent Office: Days
• US Class Current: 428/319.1
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 15/095 comprising polyurethanes
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2266/08 Closed cell foam
• CPC Class Codes: B32B 2305/02 Cellular or porous
• CPC Class Codes: B32B 2605/08 Cars
• CPC Class Codes: B32B 5/02 characterised by structural features of a fibrous or filamentary layer layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: B60R 13/08 Insulating elements, e.g. for sound insulation sound insulating linings for trains B61D17/185; drivers' cabs for load-carrying vehicles insulated against vibrations or noise B62D33/0604; thermal or acoustic insulation of engines F02B77/11; damping of sounds using compensation by electro-acoustic methods G10K11/178
• CPC Class Codes: B60R 13/0815 Acoustic or thermal insulation of passenger compartments wall or roof liners integrating the insulating function B60R13/02; insulating floor mats or carpets B60N3/04
• CPC Class Codes: B60R 13/083 for fire walls or floors
• CPC Class Codes: B60R 13/0838 for engine compartments
• CPC Class Codes: B60R 13/0861 for covering undersurfaces of vehicles, e.g. wheel houses
• CPC Class Codes: B60R 13/0869 for protecting heat sensitive parts, e.g. electronic components
• CPC Class Codes: B60R 13/0884 for mounting around noise sources, e.g. air blowers
• CPC Class Codes: F02B 77/11 Thermal or acoustic insulation
• CPC Class Codes: Y10T 428/237 Noninterengaged fibered material encased [e.g., mat, batt, etc.]
• CPC Class Codes: Y10T 428/239 Complete cover or casing
• CPC Class Codes: Y10T 428/249977 Specified thickness of void-containing component [absolute or relative], numerical cell dimension or density
• CPC Class Codes: Y10T 428/249981 : Plural void-containing components
• CPC Class Codes: Y10T 428/24999 : Inorganic

Abstract

A foam barrier heat shield is provided having a layer of foam adhesively disposed between opposing first and second metallic outer layers. The foam is expanded in between the outer layers and is adhesively formed to the outer layers without the use of a separate adhesive. In addition to shielding heat, the heat shield is effective as a noise barrier and is internally damped against vibration. In a preferred embodiment, the foam is a substantially rigid polyurethane foam that is sufficiently pliant to be bent to and accommodate a particular shape and contour to which the heat shield will conform in use, and it is reversibly deformable acoustical deflections.

Claims

1. A heat shield comprising a first metallic outer layer, a second metallic outer layer, and a foam layer disposed in between said first and second metallic outer layers, said first metallic outer layer having a thickness of 0.001-0.02 inches.

2. A heat shield according to claim 1, said first and second metallic outer layers having substantially the same thickness.

3. A heat shield according to claim 1, said first and second metallic outer layers being made from the same metal or metal alloy.

4. A heat shield according to claim 1, said foam being effective to withstand operative heat shield temperatures of at least 1000°

F., and to dampen acoustic tonal frequencies below 2000 Hz.

5. A heat shield according to claim 4, said foam comprising polyurethane foam.

6. A heat shield according to claim 4, said foam layer comprising a substantially rigid polyurethane foam that is sufficiently pliant to be bent to and accommodate a particular shape and contour to which the heat shield is to be bent and to generally conform in use, without substantially damaging the cellular structure of the foam as a result of such bending, said polyurethane foam being reversibly deflectable from the force of an impacting acoustical wave to a sufficient extent to absorb or redirect a portion of the wave'"'"'s acoustical energy.

7. A heat shield according to claim 1, said foam being a semi-rigid viscoelastic foam.

8. A heat shield according to claim 1, said foam being deformable to accommodate a particular shape and contour to which the heat shield is to be bent and to generally conform in use, without substantially damaging the cellular structure of the foam as a result of such deformation.

9. A heat shield according to claim 1, said foam being reversibly deflectable from the force of an impacting acoustical wave to a sufficient extent to absorb or redirect a portion of the wave'"'"'s acoustical energy.

10. A heat shield according to claim 1, said foam being a substantially rigid foam that is reversibly deflectable from the force of an impacting acoustical wave to a sufficient extent to absorb or redirect a portion of the wave'"'"'s acoustical energy.

11. A heat shield according to claim 10, said foam being at least 95 percent recoverable from an acoustical deflection.

12. A heat shield according to claim 1, said foam layer having a thickness of 0.005-0.75 inches.

13. A heat shield according to claim 1, said foam layer having a thickness of 0.15-0.17 inches.

14. A heat shield according to claim 1, said foam layer being made as an expanded foam layer between the first and second metallic outer layers, such that the foam layer is adhesively bonded to adjacent surfaces of the respective first and second metallic outer layers without a separate adhesive or adhesive layer.

15. A heat shield according to claim 1, further comprising a porous material layer embedded within said foam layer.

16. A heat shield according to claim 15, said porous material layer being a fiber mat being made from non-woven fibers.

17. A heat shield according to claim 16, said fibers being polypropylene fibers.

18. A heat shield according to claim 15, said porous material layer being spaced substantially equidistant from the first and second metallic outer layers, and having a thickness of about 2-2.5 mm.

19. A heat shield according to claim 1, further comprising an absorber layer comprising fluffy fibers laminated to the second metallic outer layer opposite the foam layer, said absorber layer having a thickness of about ¼

to ½

inch.

20. A heat shield according to claim 19, said absorber layer comprising polyester fluffy fibers, polyethylene fluffy fibers, or a mixture thereof.

21. A heat shield according to claim 1, said foam layer being made from an expandable foaming composition comprising 10-40 weight percent of a first polyol, 20-50 weight percent of a second polyol, 5-20 weight percent isocyanate excluding the weight of the molecule(s) to which the isocyanate groups are attached, 0-0.5 weight percent tin catalyst, 0.2-2 weight percent amine catalyst, 0-2.5 weight percent surfactant, and 0.1-5 weight percent foaming agent, wherein the first polyol has a molecular weight of 200-600 and a hydroxyl number of 200-600, and the second polyol has a molecular weight of 2000-8000 and a hydroxyl number of 10-200.

22. A heat shield according to claim 21, said first and second polyols being sucrose-based and glycerin-based polyols respectively.

23. A heat shield according to claim 21, said isocyanate being provided in the form of an allophanate-modified diphenylmethanediisocyanate.

27. An automobile body panel having the heat shield of claim 1 fastened or mounted to the body panel.

28. An automobile body panel according to claim 27, said foam being effective to withstand operative heat shield temperatures of at least 1000°

F., and to dampen acoustic tonal frequencies below 2000 Hz.

29. An automobile body panel according to claim 27, said foam being a substantially rigid polyurethane foam that is sufficiently pliant to be bent to and accommodate a particular shape and contour to which the heat shield is to be bent and to generally conform in use, without substantially damaging the cellular structure of the foam as a result of such bending, said polyurethane foam being reversibly deflectable from the force of an impacting acoustical wave to a sufficient extent to absorb or redirect a portion of the wave'"'"'s acoustical energy.

30. An automobile body panel according to claim 29, said foam being at least 95 percent recoverable from an acoustical deflection.

31. An automobile body panel according to claim 27, said foam layer having a thickness of 0.005-0.75 inches.

32. An automobile body panel according to claim 27, said foam layer being made as an expanded foam layer between the first and second metallic outer layers, such that the foam layer is adhesively bonded to adjacent surfaces of the respective first and second metallic outer layers without a separate adhesive or adhesive layer.

33. A heat shield according to claim 1, having an area density less than 0.35 lb/ft².

34. An automobile body panel according to claim 27, said heat shield having an area density less than 0.35 lb/ft².

35. A heat shield according to claim 1, said heat shield being internally damped against vibration.

36. An automobile body panel according to claim 27, said heat shield being internally damped against vibration.

24. A heat shield comprising a metallic outer layer, a semi-rigid foam layer made from a first foam material adhered to said metallic outer layer, and a foam layer absorber made from a second foam material, dissimilar to the first foam material, adhered to said semi-rigid foam layer opposite the metallic outer layer.

25. A heat shield according to claim 24, said metallic outer layer being an aluminum layer having a thickness of 0.001-0.02 inches, said semi-rigid foam layer being a polyurethane foam layer having a thickness of 0.005-0.75 inches, and said foam layer absorber being a closed cell foam layer having a thickness of about ¼

to ½

inch.

26. A heat shield according to claim 24, said foam layer absorber being a closed cell polyvinyl nitrile foam layer.