Patent ID: 6830796
Filing Date: 2004-12-14
Classification: B32B,B64D,Y10T

Abstract:
An acoustic board having an improved composite structure (1), suitable for reducing the sound of aircraft engines, which consists essentially of an outer upper layer, consisting of a fabric (7), made of a material selected from the group consisting of metallic fibers, graphite and nylon having nominal resistance and a high sensitivity to sound particle velocity, said outer upper layer being disposed over a lower perforated supporting sheet (4) having higher porosity than said outer upper layer, said lower perforated supporting sheet (4) having an upper surface and a lower surface, said supporting sheet (4) being attached at its upper surface to said fabric (7) and at its lower surface to an intermediate honeycomb layer said intermediate honeycomb layer being closed by a lower layer (5) for the structure (1).