Sheet type semi-finished product useful for producing thermoformed, acoustically active molded parts, comprises core made of mat shaped layer of fibrous materials, preferably heterogeneous fiber blends, or open- or mixed-cell foam material

摘要

Sheet type semi-finished product comprises at least a core made of mat shaped layer of fibrous materials, preferably heterogeneous fiber blends, or an open- or mixed-cell foam material or mixtures of fibrous materials and foam material. The mat shaped layer is impregnated with an impregnate comprising a thermally-curable binder and a thermally expandable filler. The filler forms gas-filled cavities or regions of reduced density in the thermally expanded state. Independent claims are also included for: (1) a thermoformed acoustically active molded part; (2) producing the sheet type semi-finished product for producing thermoformed, acoustically active molded part, comprising (a) a providing the mat shaped layer, (b) providing the impregnate, (c) impregnating the mat shaped layer with the impregnate, and (d) drying the impregnated mat shaped layer; and (3) producing the thermoformed acoustically active molded part, comprising (i) introducing a section of the sheet type semi-finished product in the open cavity of a heated molding tool, (ii) closing the cavity of the molding tool and thermoforming acoustically active molded part of the sheet type semi-finished product under thermal curing of the binder and thermal expansion of the filler.