LIGHT WEIGHT ACOUSTIC TRIM PART

• US 20170361785A1
• Filed: 10/26/2015
• Published: 12/21/2017
• Est. Priority Date: 10/30/2014
• Status: Active Grant

• Current Assignee: Autoneum Management AG (Autoneum Holding AG)
• Original Assignee: Autoneum Management AG (Autoneum Holding AG)
• Inventors: GUIGNER, Delphine, SAVALIYA, Vipul, SEPPI, Marco
• Granted Patent: US 10,457,225 B2
• Time in Patent Office: Days
• 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 13/083 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: G10K 11/168 Plural layers of different materials, e.g. sandwiches

Abstract

Multilayer sound attenuating trim part for a vehicle, in particularly for a trim part or cladding used in the interior of a car, for instance as an inner dash or as part of the floor covering or for the exterior of a vehicle, for instance as a trim part or cladding in the engine bay area or as part of an under body trim part as well as to the method of producing a part, comprising at least two fibrous layers (10, 30) and at least one air permeable intermediate film layer (20) between the at least two fibrous layers, whereby all layers together have a variable thickness.

Claims

1. Multilayer Automotive trim part for noise attenuation comprising at least 2 fibrous layers and at least one air permeable intermediate film layer between the at least 2 fibrous layers, whereby all layers together have a variable thickness characterized in that at least for an area with a thickness between 4 and 12.5 mm the overall air flow resistance (AFR_overall) and the overall density ρ

relate as follows 1500<

AFR_overall−

10ρ

<

3800 with AFR_overall in Nsm<sup>−

3</sup> and ρ

in kg/m³.

3. Automotive trim part according to claim 1, wherein the air flow resistance of the top layer and the intermediate layer together represents at least 55% of the overall AFR of the multilayer, preferably between 65% and 80% of the overall AFR of the multilayer.

4. Automotive trim part according to claim 1, wherein the AFR of the intermediate film layer is higher than the AFR of the at least 2 fibrous layers.

5. Automotive trim part according claim 1, wherein at least one of the fibrous layers comprises a mixture of fibers consisting of 10 to 40% by weight of binder fibers, 10 to 70% by weight of recycled fibers and 10 to 70% by weight of self-crimped fibers wherein the total amount of said fibers adds to 100% by weight.

6. Automotive trim part according to claim 1, wherein at least one of the fibrous layers comprises a mixture of fibers consisting of 10 to 40% by weight of binder fibers, 10 to 70% by weight of recycled fibers wherein the total amount of said fibers adds to 100% by weight.

7. Automotive trim part according to claim 1, wherein at least one of the fibrous layers comprises a mixture of fibers consisting of 10 to 40% by weight of binder fibers, 10 to 70% by weight of recycled fibers and 10 to 70% by weight of synthetic fibers wherein the total amount of said fibers adds to 100% by weight.

8. A multilayer acoustic trim part according to claim 1, wherein the air permeable intermediate film layer is one of a single layer film or a multilayer film.

9. A multilayer acoustic trim part according claim 8, wherein the film is made with at least one of the following polymers:

copolymer or polymer of acetate, like Ethylene Vinyl Acetate (EVA), copolymers of acrylate for instance Ethylene Acrylic Acid (EAA), a polyolefin for instance a polyethylene (PE) based polymer, like linear density polyethylene (LDPE), linear long density polyethylene (LLDPE) or a metallocene linear long density polyethylene (mLLDPE) or derivatives, or a multilayer film, preferably a combination of a polyethylene based copolymer film covered with an adhesive EAA layer at least at one side.

10. A multilayer acoustic trim part according to claim 1, wherein the film is replaced by one of:

a nonwoven scrim, a hot melt layer, a gluing web or adhesive layer.

11. A multilayer acoustic trim part according to claim 1, wherein the binder fibers are one of a mono-component fiber or bi-component fiber made with at least one of the following materials, polyester, in particularly polyethylene terephthalate, polyolefins, in particularly Polypropylene or polyethylene, polylactic acid (PLA) or polyamide.

12. A multilayer acoustic trim part according to claim 1, wherein the recycling fibers are one of a cotton shoddy, a synthetic shoddy, a polyester shoddy, a natural fiber shoddy, or a mixed synthetic fiber and natural fiber shoddy.

13. A multilayer acoustic trim part according to claim 1, wherein the self-crimped or synthetic fibers are made with at least one of the following materials polyamide (nylon) preferably polyamide 6 or polyamide 6,6, polyester and or its copolymers, preferably polyethylene terephthalate or polybutylene terephthalate, or polyolefin, preferably polypropylene or polyethylene, or made of a polymer and its copolymer, preferably polyethylene terephthalate and its copolymer.

14. A multilayer acoustic trim part according to claim 1, wherein the self-crimped fibers are conjugate fibers made of at least 2 sides with a difference between the two sides inducing an intrinsic self-crimping of the fiber in a random 3 dimensional form.

15. A multilayer acoustic trim part according to claim 1, further comprising at least one of a covering scrim layer, an acoustic scrim layer, a decorative top layer, for instance a tufted carpet layer or nonwoven carpet layer.

16. Use of the multilayer acoustic trim part according claim 1, as an interior trim part for instance as an inner-dash, as part of an interior flooring system, or as an inner wheel house lining or as an acoustic cladding, or as an engine bay trim part, for instance a hood liner or outer-dash.

2. Multilayer Automotive trim part for noise attenuation comprising at least 2 fibrous layers and at least one air permeable intermediate film layer between the at least 2 fibrous layers, whereby all layers together have a variable thickness characterized in that at least for an overall density above 250 kg/m³ the overall air flow resistance (AFR_overall) and the overall density ρ

relate as follows 1500<

AFR_overall−

10ρ

<

3800 with AFR_overall in Nsm<sup>−

3</sup> and ρ

in kg/m³.