COMPOSITE ACOUSTIC LAYER

Abstract

A composite acoustic layer is provided including a first nonwoven material consisting of filaments having a linear density in the range of 2 to 25 dtex, wherein the first nonwoven material is a thermally bonded nonwoven material, and including a second nonwoven material connected to the first nonwoven material, wherein the second nonwoven material is a carded staple fiber nonwoven, and wherein the composite acoustic layer has a total weight in the range of 100 g/m.sup.2 to 500 g/m.sup.2.

Claims

1. A composite acoustic layer comprising a first nonwoven material consisting of filaments having a linear density in the range of 2 to 50 dtex, wherein the first nonwoven material is a thermally bonded nonwoven material, and comprising a second nonwoven material connected to the first nonwoven material, wherein the second nonwoven material is a carded staple fiber nonwoven, and wherein the composite acoustic layer has a total weight in the range of 100 g/m.sup.2 to 500 g/m.sup.2.

2. The composite acoustic layer according to claim 1 wherein the first nonwoven material comprises a first polymer having a first melting temperature and a second polymer having a second melting temperature which is lower than the first melting temperature.

3. The composite acoustic layer according to claim 2 wherein the first polymer is comprised in first monocomponent filaments and the second polymer is comprised in second monocomponent filaments.

4. The composite acoustic layer according to claim 2 wherein the first polymer is comprised in a first component of bicomponent filaments and the second polymer is comprised in a second component of bicomponent filaments.

5. The composite acoustic layer according to claim 1 wherein the composite acoustic layer comprises an adhesive.

6. The composite acoustic layer according to claim 5 wherein the adhesive is an adhesive powder.

7. The composite acoustic layer according to claim 6 wherein the adhesive powder is a polyethylene powder.

8. The composite acoustic layer according to claim 1 wherein the second nonwoven material is a carded staple fiber nonwoven consisting of staple fibers having a linear density of 3 dtex or less.

9. The composite acoustic layer according to claim 1 wherein the composite acoustic layer has a Rayl value in the range from 300 Rayls to 7500 Rayls.

10. The composite acoustic layer according to claim 9 wherein the composite acoustic layer has a Rayl value in the range from 3500 Rayls to 7500 Rayls.

11. The composite acoustic layer according to claim 1 wherein the composite acoustic layer has a thickness of 10 mm or less.

12. A noise vibration harshness product comprising the composite acoustic layer according to any of claim 1.

13. The noise vibration harshness product according to claim 12 comprising the composite acoustic layer attached to a substrate.

14. The noise vibration harshness product according to claim 12 wherein the noise vibration harshness product has a Rayl value in the range from 3700 Rayls to 5500 Rayls.

15. The noise vibration harshness product according claim 12 wherein the noise vibration harshness product is tufted car carpet, a dashboard system or a trunk system.

Description

EXAMPLE 1

[0057] A carded staple fiber nonwoven of 55.2 g/m.sup.2 was provided composed of core/sheath bicomponent staple fibers having a linear density of 2 dtex and a staple fiber length of 2 inch (5.1 mm). The bicomponent staple fibers comprised 50 wt. % of a core composed of polyethylene terephthalate and 50 wt. % of a sheath composed of polyethylene. A polyethylene powder was applied onto the carded staple fiber nonwoven in an amount of 9.2 g/m.sup.2 by two applicators prior to an oven. The dried carded staple fiber nonwoven comprising the PE powder was at the exit nip of the oven at a temperature of 140 C. combined with a nonwoven composed of core/sheath bicomponent filaments having a linear density of 15 dtex comprising 76 wt. % of a core composed of polyethylene terephthalate and 24 wt. % a sheath composed of polyamide-6, and having a weight of 50 g/m.sup.2, to form the composite acoustic layer.

[0058] The composite acoustic layer had a total average weight of 114.4 g/m.sup.2, and an average thickness of 0.5 mm. The composite acoustic layer had an average air flow resistance (AFR) of 15 Pa.Math.s/m, corresponding to 390 Rayls.

[0059] The composite acoustic layer had an average breaking strength of 326 N/5 cm in machine direction and 210 N/5 cm cross machine direction, an average elongation at break 39% in machine direction and 66% in cross machine direction, and a load at specified elongation of 2% of 125 N/5 cm in machine direction and 59 N/5 cm in cross machine direction.

Example 2

[0060] A carded staple fiber nonwoven of 75.3 g/m.sup.2 was provided composed of core/sheath bicomponent staple fibers having a linear density of 2 dtex and a staple fiber length of 2 inch (5.1 mm). The bicomponent staple fibers comprised 50 wt. % of a core composed of polyethylene terephthalate and 50 wt. % of a sheath composed of polyethylene. A polyethylene powder was applied onto the carded staple fiber nonwoven in an amount of 9.2 g/m.sup.2 by two applicators prior to an oven. The dried carded staple fiber nonwoven comprising the PE powder was at the exit nip of the oven at a temperature of 140 C. combined with a nonwoven composed of core/sheath bicomponent filaments having a linear density of 15 dtex comprising 76 wt. % of a core composed of polyethylene terephthalate and 24 wt. % a sheath composed of polyamide-6, and having a weight of 50 g/m.sup.2, to form the composite acoustic layer.

[0061] The composite acoustic layer had a total average weight of 134.5 g/m.sup.2, and an average thickness of 0.5 mm. The composite acoustic layer had an average air flow resistance of 23 Pa.Math.s/m, corresponding to 598 Rayls.

[0062] The composite acoustic layer had an average breaking strength of 378 N/5 cm in machine direction and 259 N/5 cm cross machine direction, an average elongation at break 39% in machine direction and 63% in cross machine direction, and a load at specified elongation of 2% of 141 N/5 cm in machine direction and 81 N/5 cm in cross machine direction.

Example 3

[0063] A carded staple fiber nonwoven of 75.3 g/m.sup.2 was provided composed of core/sheath bicomponent staple fibers having a linear density of 2 dtex and a staple fiber length of 2 inch (5.1 mm). The bicomponent staple fibers comprised 50 wt. % of a core composed of polyethylene terephthalate and 50 wt. % of a sheath composed of polyethylene. A polyethylene powder was applied onto the carded staple fiber nonwoven in an amount of 13.4 g/m.sup.2 by two applicators prior to an oven. The dried carded staple fiber nonwoven comprising the PE powder was at the exit nip of the oven at a temperature of 140 C. combined with a nonwoven composed of core/sheath bicomponent filaments having a linear density of 15 dtex comprising 76 wt. % of a core composed of polyethylene terephthalate and 24 wt. % a sheath composed of polyamide-6, and having a weight of 50 g/m.sup.2, to form the composite acoustic layer.

[0064] The composite acoustic layer had a total average weight of 138.7 g/m.sup.2, and an average thickness of 0.5 mm. The composite acoustic layer had an average air flow resistance of 30 Pa.Math.s/m, corresponding to 780 Rayls.

[0065] The composite acoustic layer had an average breaking strength of 410 N/5 cm in machine direction and 306 N/5 cm cross machine direction, an average elongation at break 42% in machine direction and 68% in cross machine direction, and a load at specified elongation of 2% of 143 N/5 cm in machine direction and 88 N/5 cm in cross machine direction.

Example 4

[0066] A carded staple fiber nonwoven of 75.3 g/m.sup.2 was provided composed of core/sheath bicomponent staple fibers having a linear density of 2 dtex and a staple fiber length of 2 inch (5.1 mm). The bicomponent staple fibers comprised 50 wt. % of a core composed of polyethylene terephthalate and 50 wt. % of a sheath composed of polyethylene. A polyethylene powder was applied onto the carded staple fiber nonwoven in an amount of 16.7 g/m.sup.2 by two applicators prior to an oven. The dried carded staple fiber nonwoven comprising the PE powder was at the exit nip of the oven at a temperature of 140 C. combined with a nonwoven composed of core/sheath bicomponent filaments having a linear density of 15 dtex comprising 76 wt. % of a core composed of polyethylene terephthalate and 24 wt. % a sheath composed of polyamide-6, and having a weight of 50 g/m.sup.2, to form the composite acoustic layer.

[0067] The composite acoustic layer had a total average weight of 142 g/m.sup.2, and an average thickness of 0.5 mm. The composite acoustic layer had an average air flow resistance of 35 Pa.Math.s/m, corresponding to 910 Rayls.

[0068] The composite acoustic layer had an average breaking strength of 422 N/5 cm in machine direction and 330 N/5 cm cross machine direction, an average elongation at break 39% in machine direction and 69% in cross machine direction, and a load at specified elongation of 2% of 155 N/5 cm in machine direction and 97 N/5 cm in cross machine direction.

Example 5

[0069] A carded staple fiber nonwoven of 100.3 g/m.sup.2 was provided composed of core/sheath bicomponent staple fibers having a linear density of 2 dtex and a staple fiber length of 2 inch (5.1 mm). The bicomponent staple fibers comprised 50 wt. % of a core composed of polyethylene terephthalate and 50 wt. % of a sheath composed of polyethylene. A polyethylene powder was applied onto the carded staple fiber nonwoven in an amount of 16.7 g/m.sup.2 by two applicators prior to an oven. The dried carded staple fiber nonwoven comprising the PE powder was at the exit nip of the oven at a temperature of 140 C. combined with a nonwoven composed of core/sheath bicomponent filaments having a linear density of 15 dtex comprising 76 wt. % of a core composed of polyethylene terephthalate and 24 wt. %, a sheath composed of polyamide-6, and having a weight of 50 g/m.sup.2, to form the composite acoustic layer.

[0070] The composite acoustic layer had a total average weight of 167 g/m.sup.2, and an average thickness of 0.6 mm. The composite acoustic layer had an average air flow resistance of 55 Pa.Math.s/m, corresponding to 1430 Rayls.

[0071] The composite acoustic layer had an average breaking strength of 494 N/5 cm in machine direction and 333 N/5 cm cross machine direction, an average elongation at break 45% in machine direction and 70% in cross machine direction, and a load at specified elongation of 2% of 170 N/5 cm in machine direction and 101 N/5 cm in cross machine direction.