Sandwich element for the sound-absorbing inner cladding of means of transport, especially for the sound-absorbing inner cladding of aircraft

Abstract

A sandwich element for sound-absorbing inner cladding of means of transport, especially aircraft, comprising a three-dimensionally constructed core disposed between two substantially parallel cover layers is provided. Sound transmission passages are incorporated in the core, and/or in at least one cover layer. At least one sound absorption layer is in the area of a cover layer at least in parts. Passages in the cover layers and core provide good sound absorption and heat insulation. The passages allow transmission of sound. The through channels and the preferably inclined installation of the sandwich element allow foreign bodies to be flushed out by, for example, a cleaning liquid or condensation. Possibly sufficient sound absorption can be achieved without the sound absorption layer. Ventilation of the core prevents the long-term presence of condensation, which could cause corrosion and/or rotting. A fire-retardant layer including metal particles may increase fire protection and electromagnetic insulation.

1 . A sandwich element for providing a sound-absorbing inner cladding of means of transport, especially for a sound-absorbing inner cladding of aircraft, the sandwich element comprising:
 a three-dimensionally constructed core structure which is disposed between two cover layers which run substantially parallel to one another at a distance;   wherein a plurality of passages for sound transmission, disposed in a perforation-like manner, are incorporated respectively in the core structure and in both cover layers;   wherein the core structure comprises a plurality of through channels disposed adjacent to one another and parallel to the cover layers;   wherein the trough channels are adapted for drainage of fluids and for flushing out foreign bodies;   wherein the core structure is coated with a fire retardant layer;   and wherein at least one sound absorption layer is disposed in at least part of an area of a cover layer.   
     
     
         2 . The sandwich element according to  claim 1 , wherein the channels have flanks;
 wherein the flanks each form a continuous, substantially flat and/or curved surface.   
     
     
         3 . The sandwich element according to  claim 1 , wherein the channels have flanks which are formed with a plurality of substantially flat and/or curved partial surfaces, wherein the partial surfaces adjoin one another at an angle of less than 180°. 
     
     
         4 . The sandwich element according to  claim 1 , wherein the core structure has a repetitive triangular, trapezoidal, rectangular or wavy cross-sectional geometry. 
     
     
         5 . The sandwich element according to  claim 1 , wherein the passages are especially constructed as cylindrical, elliptical or polygonal openings. 
     
     
         6 . The sandwich element according to  claim 1 , wherein the sound absorption layer is constructed as thermally insulating. 
     
     
         7 . The sandwich element according to  claim 1 , wherein the core structure and/or the cover layers are formed with a plastic material. 
     
     
         8 . The sandwich element according to  claim 1 , wherein the core structure and/or the cover layers are formed with a fibre-reinforced plastic material. 
     
     
         9 . The sandwich element according to  claim 1 , wherein the core structure and/or the cover layers are formed with a metal material. 
     
     
         10 . The sandwich element according to  claim 1 , wherein the fire retardant layer comprises an intumescent material. 
     
     
         11 . The sandwich element according to  claim 1 , wherein the fire retardant layer comprises a glass forming material. 
     
     
         12 . The sandwich element according to  claim 1 , wherein the fire retardant layer comprises metal particles.