Patent ID: 6755280
Filing Date: 2004-06-29
Classification: F02C,G10K,Y02T

Abstract:
Process for the production of a panel with a fitted acoustically resistive layer comprising at least one central core of porous structure bounded on a first side with a structural layer, the structural layer covered with a porous acoustically resistive layer and, bounded on a second side with a total acoustical reflector, comprising the successive steps of:laying down said acoustically resistive layer in strips on a mold according to a profile of the panel to be obtained; placing said structural layer on said resistive layer; placing said core with a porous structure on said structural layer; placing said total reflector on said core; and withdrawing the mold from the thus-formed panel, wherein, there is first produced a continuous strip of acoustically resistive material constituted by end to end sections of different porosities and said strip is laid down on the mold to form said acoustically resistive layer, and the porosity and length of each section as well as a method of laying down each section is predetermined such that once the acoustically resistive layer is laid down, the acoustically resistive layer will be divided into at least as many contiguous regions as the different porosities in said strip, in correspondence with different acoustical zones detected during a preliminary correlation carried out with help of conventional acoustic techniques on a test panel identical to that to be produced.