Sound absorbing material

Abstract

To satisfy the fire protection requirements for a sound-absorbing material, especially in the form of open-cell foam, without impairing the acoustic properties, at least a part of the surface of the sound-absorbing material, which is covered with an acoustically transparent film, is coated with a flame-retarding powder or sprayed with a flame-retarding solution.

1 . Sound-absorbing material, especially in the form of open-cell foam, which is covered by an acoustically transparent film ( 3 ) wherein at least a part of the surface of the sound-absorbing material is coated with a flame-retarding powder ( 2 ) or sprayed with a flame-retarding solution 
   
   
       2 . Sound-absorbing material according to  claim 1 , wherein the flame-retarding powder is mixed with adhesive. 
   
   
       3 . Sound-absorbing material according to  claim 1  or  2 , wherein the film ( 3 ) completely encases the absorber material ( 1 ) 
   
   
       4 . Sound-absorbing material according to one of the preceding claims, wherein the layer of flame-retarding material ( 2 ) is arranged between the acoustically transparent film ( 3 ) and the absorber material ( 1 ). 
   
   
       5 . Sound-absorbing material according to one of  claims 1  to  3 , wherein the flame-retarding coating ( 2 ) is applied to the outside of the acoustically transparent film ( 3 ). 
   
   
       6 . Sound-absorbing material according to  claim 4  or  5 , wherein a fleece ( 4 ) is arranged on the one and/or on the other side of the layer of flame-retarding material ( 2 ). 
   
   
       7 . Sound-absorbing material according to one of  claims 1  to  3 , wherein the flame-retarding material ( 2 ) is incorporated in a fleece ( 4 ) which is arranged between the acoustically transparent film ( 3 ) and the foam material ( 1 ).