Noise attenuating trim part for a vehicle

Abstract

Noise attenuating trim part for a vehicle comprising a pile layer, a bonding mass layer and a backing layer whereby the bonding mass layer is bonded to the adjacent layers whereby the bonding mass layer is comprising at least thermoplastic elastomeric polyolefin based compound material (TPO) with a filler content of at least 55%, and whereby the bonding mass layer has a density of between 1.4 and 1.75 kg/dm.sup.3, a viscosity of less than 50.000 mPa.Math.s and a MFI above 250 and whereby the bonding mass layer is adjacent the pile layer and partly penetrated into the lower area of the pile thereby binding the fibers and/or filaments and/or the tufts within the pile.

Claims

1. A noise attenuating trim part for a vehicle, comprising: a pile layer; a backing layer; a bonding mass layer is bonded to the pile layer and the backing layer; wherein the bonding mass layer comprises at least one thermoplastic elastomeric polyolefin based compound material (TPO) with a filler content of at least 55% by weight of the overall bonding mass layer; wherein the bonding mass layer has a density of between 1.4 and 1.75 kg/dm.sup.3, a viscosity of less than 50,000 mPa.Math.s; wherein the bonding mass layer is adjacent to the pile layer and partly penetrated into a lower area of the pile layer, thereby binding fibers, filaments, yarn, and/or tufts of the pile layer; and wherein the TPO consists of a first component consisting of at least one of a partially amorphous polyolefin, and a second component consisting of a PP-Ethylene with a random ethylene repeat distribution having a specific density of less than 0.87 kg/dm3.

2. The noise attenuating trim part according to claim 1, whereby the first component is at least 3% by weight of the bonding mass layer and the second component is at least 7% by weight of the bonding mass layer.

3. The noise attenuating trim part according to claim 2, wherein the first and second component together are 10-48% by weight of the bonding mass layer.

4. The noise attenuating trim part for a vehicle according to claim 1, characterized in that the bonding mass layer further comprises at least one fatty acid and optional additives, and whereby the filler is between 55 and 70% by weight of the bonding mass layer, and a fatty acid content of the fatty acid is between 0.2 and 0.8% by weight of the bonding mass layer.

5. The noise attenuating trim part for a vehicle according to claim 1, whereby the bonding mass layer has an area weight of between 100 and 980 g/m.sup.2.

6. The noise attenuating trim part according to claim 4, whereby the fatty acid comprises at least fatty acids with an aliphatic chain of at least 14.

7. The noise attenuating trim part according to claim 1, whereby the bonding mass layer comprises a constant area weight over the surface of the noise attenuating trim part.

8. The noise attenuating trim part according to claim 1, whereby the pile layer has an area weight of between 400 and 2000 g/m.sup.2.

9. The noise attenuating trim part according to claim 1, whereby the pile layer is one of a tufted carpet layer consisting of BCF yarn tufted into a primary backing layer, or a needle punch carpet layer with a densified sole area and a surface area formed of looped fibers standing substantially perpendicular to the surface comprising of a least one of solid fibers, hollow fibers, binder fibers or bicomponent fibers.

10. The noise attenuating trim part according to claim 1, wherein fibers, filaments, and/or yarn of the pile layer are made of at least one polymer or co-polymer from a group consisting of group of polyester, polyamides, polyolefins, polyethlene (PE), or mixtures from two or more thereof.

11. The noise attenuating trim part according to claim 1, wherein the backing layer is at least one of a fibrous layer, a foam layer, or in mold reactive foam layer.

12. The noise attenuating trim part according to claim 1, further comprising at least partially at least one additional layer or patch between the bonding mass layer and a decoupling layer comprising a high density thermoplastic elastomeric layer, a film layer, or an air flow resistive fibrous layer, the air flow resistive fibrous layer having an air flow resistance of at least 1000 Rayls.

13. The noise attenuating trim part according to claim 12, whereby the high density thermoplastic elastomeric layer is impervious and has area weight between 800 and 2000 g/m.sup.2.

14. An automotive flooring, inner dash, outer dash, acoustic trim panel, or trunk covering comprising the noise attenuating trim part of claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a cross-section view showing the carpet system of the prior art.

(2) FIG. 2 is a cross-section view showing the noise attenuating trim part of one embodiment of the present invention.

(3) FIG. 3 is a cross-section view showing the noise attenuating trim part of one embodiment of the present invention.

(4) FIG. 4 shows a production process of one embodiment of the present invention.

DETAILED DESCRIPTION

(5) FIG. 1 shows an automotive carpet system according to the state of the art with following consecutive layers (the layers are not drawn in real thickness relation to each other): The visible surface of carpet formed by a pile 2. The pile might be a tufted pile 3, consisting of yarn tufts in loop and/or cut configuration. The yarn is tufted in a fabric called the primary backing layer 4. The pile can also be a needle punch type face layer, whereby due to variable needling steps, for instance alternating steps with fork and crown needles a tufted pile appearance is mimicked. (not shown) A back coating or precoat 5 is applied to the surface opposite the pile. The function of the back coating is the binding of the fibers or filaments within the construction and/or, in case of tufted pile, the binding of the tufts to the primary backing. The back coating prevents the pull out of single fibers, filaments, and/or full tufts. In most cases, a latex coating is used as back coating layer preparing the surface and enabling a good lamination to the following layer. The latex coating is meant to penetrate the lower area of the pile and eventually the primary backing layer, to get this effect a frothed or foamed latex is applied to the back. This effects in a not full coverage of the surface by the latex and/or an uneven coated layer. Latex is unwanted for environmental reasons including recycling of waste and end-of-life products containing latex. A further back coating layer 6, also known as secondary backing layer, is used to enhance the stiffness and durability of the pile layer. It in particular enhances the abrasion performance of the pile.

(6) The thus formed carpet system might be placed on top or is laminated to an insulating mass spring system with a mass layer (also called heavy layer or barrier) 7 normally formed of an extruded blank of highly filled thermoplastic material and a soft decoupling layer 8 made of either a foam or a felt material.

(7) Surprisingly, the bonding mass layer according to the invention is able to replace the backing layers (B) formed by the back coating 5, the secondary backing layer 6, and the barrier layer 7 of a classical system according to FIG. 1 while maintaining the functions of these layers.

(8) FIGS. 2 and 3 show noise attenuating trim parts with a layout according to the invention.

(9) FIG. 2 shows a basic construction according to the invention with a pile 2 formed by a tufted yarn 3 tufted in a primary backing 4.

(10) FIG. 3 shows a basic construction according to the invention with a needle punch carpet layer 9 whereby the reciprocal action of fork and or crown needles a carpet surface layer is produced from a mat of fibers with a densified area 9b and a looser top area mimicking a tufted pile appearance and hand 9a.

(11) In both pile carpet systems according to the invention, the precoat 5, secondary backing layer 6, and the barrier layer 7 of the state of the art as shown in FIG. 1 are replaced by one single layer, the bonding mass layer 10. This layer is surprisingly able to bond the fibers or filaments as well as the tufts and the primary backing in the tufted pile, or to bond the fibers in the needle punch pile layer, to enhance the stiffness of the carpet structure and to function as a barrier layer depending on its weight being above roughly 400 g/m.sup.2.

(12) With the bonding mass layer 10 according to the invention, a multipurpose layer was created that is able to replace three layers, simplifying the carpet construction of the state of the art and reducing the production process steps accordingly. Saving materials and resources.

(13) FIG. 4 shows a preferred production process for the pile carpet system according to the invention. Via one or two hoppers 20, 21 the thermoplastic polyolefin based resins, filler, and additives can be dosed to a single screw extruder 22. The material is compounded, heated, and melted to the preferred temperature for application.

(14) The thus prepared material 29 is dosed between a dosing roller 24 and an application roller 25. The dosing roller enables an even spread layer of the bonding mass material picked up by the application roller.

(15) A first roller 26 transports a pile layer to the counter pressure roller 27, that presses the back surface of the pile layer 2 against the application roller 25 carrying the bonding material, thereby transferring the bonding mass material to the surface of the pile layer creating a light penetration of the bonding carrier material into the pile layer. Surprisingly it is possible to create good lamination with the highly filled bonding material as well as a good even layer. Surprisingly this simple application system is able to transfer up to at least 980 g/m.sup.2, of the high filled low viscosity bonding mass material according to the invention.

(16) Surprisingly the solidified layer does not crumble or lose its flexibility after the molding of the product in a later step. Furthermore, an intended layer does not migrate during the molding step such that layer would become impaired.

(17) A second laminating roller 28 transports the backing layer 30 to the counter pressure roller 27 after the application of the bonding material to the carrier backing. The backing layer 8, such as a decoupling layer 8, is pressed against the surface of the bonding mass layer to form a sandwich of all three materials 32. Depending on the final layout of the product, the backing layer can be a film or a scrim to enable back foaming of the part in a next step or it might be a felt layer, eventually consolidated or a slab foam layer.

(18) The thus formed material might be stored on rolls or cut into blanks. Independent of the backing layer chosen, the material can be formed in thermal conversion process using cold or hot molding eventually with a preheating step.

(19) Surprisingly, it is possible to pick up the high filled carrier backing with the application roller and to transfer the material as an even layer to the fibrous layer with a final thickness within acceptable tolerances and without major flaws of the surface like folds or stretch marks.

(20) In case the backing layer is felt material, the material might be molded to fit the contours of the specific floor pan of the car eventually trimming the borders and eventually through holes for appliances, forming the final vehicle floor part. FIG. 4 gives an example of such a molded structure.

(21) In case of a foam backing layer, the same molding step as for felt may be used to pre-form the pile layer structure and a second molding step is used to back foam against the back surface of the backing layer to form the decoupler. The backing layer can be a light scrim layer or a compatible film layer either single layer or multilayer.

(22) Surprisingly the bonding mass material according to the invention is able to be transferred by a simple application or coating process. However, after solidifying the layer is stiff enough to form a good acoustic insulating barrier layer, while at the same time it is flexible enough to be molded and to maintain its barrier properties after molding into the final part.

(23) With this bonding mass material and the preferred process, it is now possible to make an economic carpet construction with less steps and the same acoustic and stiffness requirements.

(24) In case the backing layer is felt material, the material might be molded to fit the contours of the specific floor pan of the car eventually trimming the borders and eventually through holes for appliances, forming the final vehicle floor part.

(25) In case the backing layer is foam, the same molding step as for felt may be used to pre-form the pile layer structure and a second molding step is used to back foam against the back surface of the backing layer to form the decoupler 8. The backing layer can be a light scrim layer or a compatible film layer either single layer or multilayer.

(26) Surprisingly the bonding barrier material according to the invention is able to be transferred by a simple application or coating process. However, after solidifying the layer is stiff enough to form a good acoustic insulating barrier layer, while at the same time it is flexible enough to be molded and to maintain its barrier properties after molding into the final part.

(27) With this bonding barrier material and the preferred process, it is now possible to make an economic carpet construction with less steps and the same acoustic and stiffness requirements.