Fiber Composite Acoustic Damping Material

Abstract

A damping material ( 11 ) in accordance with the invention consists of a ground material that is composed of fibers that are in loose connection with each other. For example, the fibers are minimally interlooped with each other or also glued to each other. This ground material is condensed in some areas in that the fibers are reoriented or interlooped with each other to a greater degree or glued to each other. Consequently, zones ( 17 ) and ( 18 ) of different densities are formed, thus making it possible to increase and adjust, as desired, the sound-damping effect of the damping material.

1 . Acoustic damping material ( 11 ) consisting of a random-fiber non-woven body ( 10 ) that is made of interlooped fibers ( 13 ,  14 ,  15 ,  16 ) and has at least two spatial zones ( 17 ,  18 ,  28 ,  29 ) displaying different degrees of fiber interlooping. 
     
     
         2 . Damping material as in  claim 1 , characterized in that the two zones ( 17 ,  18 ,  28 ,  29 ) displaying different degrees of fiber interlooping have different fiber densities. 
     
     
         3 . Damping material as in  claim 1 , characterized in that the spatial zones ( 17 ,  18 ,  28 ,  29 ) are arranged in an irregular pattern. 
     
     
         4 . Damping material as in  claim 1 , characterized in that the fibers in the zones ( 17 ) displaying a lower degree of fiber interlooping are oriented predominantly in one plane, while, in the zones ( 18 ,  28 ,  29 ) displaying a greater degree of interlooping, a larger proportion of said fibers is oriented in a direction perpendicular to said plane. 
     
     
         5 . Damping material as in  claim 1 , characterized in that the zones ( 18 ,  28 ,  29 ) displaying the greater degree of fiber interlooping have the form of strip-shaped regions. 
     
     
         6 . Damping material as in  claim 5 , characterized in that the zones ( 18 ,  28 ,  29 ) are arranged at different distances from each other and parallel to each other. 
     
     
         7 . Damping material as in  claim 1 , characterized in that the random-fiber non-woven body ( 10 ) comprises several layers ( 32 ,  33 ) that are made of interlooped fibers ( 25 ,  26 ), whereby at least one layer ( 32 ) of said layers has the zones ( 17 ,  34 ,  35 ) displaying different degree of fiber interlooping. 
     
     
         8 . Damping material as in  claim 7 , characterized in that at least two of said layers ( 32 ,  33 ) have zones ( 17 ,  34 ,  35 ,  36 ,  37 ) displaying different degrees of fiber interlooping, said zones being arranged differently. 
     
     
         9 . Damping material as in  claim 8 , characterized in that the zones ( 17 ,  34 ,  35 ,  36 ,  37 ) of the layers ( 32 ,  33 ) are strip-shaped and are superimposed in a manner so as to cross each other. 
     
     
         10 . Damping material as in  claim 1 , characterized in that the fiber body ( 10 ) contains interstices ( 27 ,  39 ) that are free of fibers or have a fiber density that is considerably reduced compared to the surrounding fiber body ( 10 ).