Acoustic Pannelling Part for a Vehicle

Abstract

A cover part for a vehicle, especially an underbody cover, has a porous core layer and at least one cover layer on each side, wherein the porous core layer is constructed such that it has acoustic transparency or an acoustically absorbent effect. Here, the porous core layer is made either from a thermoplastic matrix with embedded reinforcement fibers, especially glass fibers, whose melting point temperature is higher than the melting point temperature of the plastic matrix, or from a foam, which is either open-cell or closed-cell and perforated. The acoustically absorbent porous core layer is occupied on one or both sides with one or more acoustically transparent or absorbent covering layers.

1 - 25 . (canceled) 
   
   
       26 . A method for producing an inherently stable, acoustically absorbent cover part for a vehicle, especially an underbody cover, comprising:
 heating an acoustically absorbent core material; and   shaping the heated core material together with one or more plastic covering layers in a mold and pressing the core material and the covering layers together.   
   
   
       27 . The method according to  claim 26 , wherein the covering layers are heated with the core material and then molded and pressed together with the core material. 
   
   
       28 . The method according to  claim 27 , wherein the covering layers are made from high-melting-point fibers and low-melting-point fibers and thus the fiber structure of the high-melting-point fibers is maintained despite the heating, while the low-melting-point fibers are used as bonding fibers. 
   
   
       29 . The method according to  claim 26 , wherein the covering layers are inserted into the mold without preheating and are molded and pressed together with the heated core material. 
   
   
       30 . The method according to  claim 26 , wherein at least one of the covering layers comprises an aluminum film with a core material-side bonding agent layer; and
 wherein inserting said covering layer into the mold with the heated core material activates the adhesive bonding agent layer which leads to a bond between the core material and the covering layer.   
   
   
       31 . The method according to  claim 30 , wherein the aluminum film is microperforated. 
   
   
       32 . The method according to  claim 26 , wherein at least one of the covering layers comprises a high-melting-point plastic film with a core material-side bonding agent layer; and
 wherein inserting said covering layer into the mold with the heated core material activates the bonding agent layer, which leads to a bond between the core material and the covering layer.   
   
   
       33 . The method according to  claim 32 , wherein the plastic film is microperforated. 
   
   
       34 . The method according to  claim 26 , wherein the core material and covering layers are vacuum shaped in the mold. 
   
   
       35 . The method according to  claim 26 , further comprising the step of introducing compressed air between the covering layers and the core material. 
   
   
       36 . The method according to  claim 26  wherein the core material comprises a nonwoven made from a thermoplastic matrix and reinforcement fibers and wherein the reinforcement fibers have a higher melting point temperature than the thermoplastic matrix. 
   
   
       37 . The method according to  claim 36  wherein the reinforcement fibers of the core material are made from polyester (PET) or from polyamide (PA) or from glass. 
   
   
       38 . The method according to  claim 36  wherein the thermoplastic matrix is made from low-melting-point-fibers. 
   
   
       39 . The method according to  claim 38 , wherein the low-melting-point fibers are made from polypropylene (PP). 
   
   
       40 . The method according to  claim 38 , wherein the low-melting-point fibers are made from polyester (PET). 
   
   
       41 . The method according to  claim 38 , wherein the low-melting-point fibers are made from polyamide (PA). 
   
   
       42 . The method according to  claim 26 , wherein the heating is realized by a radiant heater. 
   
   
       43 . The method according to  claim 26 , wherein the heating is realized by means of a contact heater. 
   
   
       44 . The method according to  claim 26 , wherein the covering layers are applied only in selected regions of at least one side of the core material. 
   
   
       45 . The method according to  claim 26 , wherein the covering layers are connected to the core material only in some regions of the core material. 
   
   
       46 . The method according to  claim 45 , wherein at least one of the covering layers is connected to the core material only in some regions of the core material through partial heating, partial ultrasonic welding, partial high frequency welding, or partial friction welding. 
   
   
       47 . The method according to  claim 45 , wherein at least one of the covering layers comprises a high-melting-point layer and a core-side low-melting-point layer; and
 wherein said covering layer, is heated to a temperature that melts only the low-melting-point layer, and then is pressed to the core material such that the low-melting-point layer contacts the core material.   
   
   
       48 . The method according to  claim 46 , wherein the core-side, low-melting-point layer is arranged only in some regions of the high-melting-point layer. 
   
   
       49 . The method according to  claim 26 , wherein the core material is made from PP foam film. 
   
   
       50 . The method according to  claim 26 , wherein the core material is made from PUR foam. 
   
   
       51 . The method according to  claim 30 , wherein the bonding agent layer comprises a low-melting-point thermoplastic. 
   
   
       52 . The method according to  claim 28 , wherein the high-melting-point fibers of the covering layers are made from polyester (PET) or from polyamide (PA) or from glass.