A sound absorber/insulator in a motor vehicle is constructed of outer layer nonwoven scrims, perforated films, and a fill material core, which are typically fibers or foams. Fibers could be of a nonorganic nature such as glass, or an organic one like polyester or cotton. Foams could be of open cell polyurethane chemistry. The materials are enveloped in a thermoforming process wherein all layers are substantially adhered to each other. The fill material is responsible for sound attenuation whereby a higher weight input provides additional attenuation benefit. Specialized technical nonwoven scrims can also be used to enhance the sound attenuation where required. Increasing absorption properties by adding weight or using highly technical nonwovens is costly and results in a weight penalty. Perforated films of certain thicknesses, hole sizes, and hole densities significantly enhance sound attenuation properties of an absorber and do so with no changes to the manufacturing process, a minimal increase in weight, and at a substantially lower cost. The films can be positioned in different locations throughout an insulator, depending on absorption requirements.
LIGHTWEIGHT PERFORATED FILMS AND THEIR USE IN ACOUSTICAL INSULATORS FOR INCREASED SOUND ABSORPTION
2022-05-19
Patent
Elektronische Ressource
Englisch
IPC: | B60R Fahrzeuge, Fahrzeugausstattung oder Fahrzeugteile, soweit nicht anderweitig vorgesehen , VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR / B32B LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM , Schichtkörper, d.h. aus Ebenen oder gewölbten Schichten, z.B. mit zell- oder wabenförmiger Form, aufgebaute Erzeugnisse / C08J Verarbeitung , WORKING-UP / G10K Tonerzeugungsvorrichtungen , SOUND-PRODUCING DEVICES |
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