Patent ID: 6820720
Filing Date: 2004-11-23
Classification: B60R,G10K

Abstract:
A sound-absorbing article which is one of a lining or a shaped element and which has a sound absorptive effect over a broad frequency range when positioned proximate a reverberant wall, the sound-absorbing article comprising:at least one microperformated sheet absorber which has microperforations defined therein having at least one hole diameter ranging from 0.05 mm to 2 mm, which has at least one interhole distance ranging from 1 mm to 20 mm, and which has a proportion of hole area ranging from 0.2 to 4%, based on surface area of the at least one microperforated sheet absorber; and at least one absorber which is at least one of a foam absorber and a non-woven absorber and which is positioned at a preselected spatial distance from a reverberant wall, wherein the sound-absorbing article is incorporated into a means for transportation as a composite article selected from the group consisting of wheel housing, hoods, hood linings, engine encapsulations, heat transfer plates, vehicle shields, transmission tunnel linings, dashboards, vehicle seats, seat backs, armrests, steering wheels, carpeting, roof linings, pillar linings, door linings, passenger compartment linings, luggage shelves, rear shelves, heat shields and trunk linings and wherein the microporated sheet absorber and the foam absorber or non-woven absorber cooperate to produce a sound absorptive effect over frequencies ranging at least from 500 Hz to 5000 Hz when positioned proximate a reverberant wall and wherein the open surface in the microperforated sheet absorber is increased by including additional holes having a surface area of from 6 mm2 to 40.000 mm2 (macro perforation).