| 摘要 |
A method of manufacturing an improved adhesive bonded acoustical attenuation structure comprising two honeycomb cores each having a multiplicity of endwise directed cells, an imperforate sheet, two perforate sheets and two sheets of porous fibrous material. The components making up the attenuation structure in order from the bottommost layer upward are the imperforate sheet, the lower core, a perforate sheet, a sheet of porous fibrous material, the second core, the second perforated sheet with the uppermost layer being the second sheet of porous fibrous material. The steps of manufacturing include cleaning and degreasing the components, applying a solvent base adhesive coating to one surface of each perforated sheet, removing the solvent from the solvent base adhesive, stacking each perforated sheet and its associated sheet of porous fibrous material, applying a positive pressure and curing the now solvent free adhesive, applying a coating of maskant material on the now perforation exposed surface of each of the perforated sheets, applying an anti-wetting solution to the fibers of the porous fibrous material, removing the coating of maskant, applying a coating of a second type adhesive between each core and its adjacent component and stacking the components in the aforementioned order, applying a positive pressure and curing the adhesive layers. An improved acoustical attenuation sandwich panel is constructed by this method.
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