Moldable fibrous composite and methods

Claim 1

A stable moldable needled fibrous composite structure, comprising: a first substrate defining a base side and a face side on opposite sides thereof, a middle layer adjacent to said face side of said first substrate, said middle layer comprising mineral fibers of sufficiently short length to substantially preclude interlocking of said mineral fibers with other fibers of said needled structure and to provide said structure with a desired degree of flexibility, said middle layer of mineral fibers initially having lacked structural integrity before being made an integral part of said composite structure, said mineral fibers being present in a quantity sufficient to impart desired heat and sound insulating properties to said structure, a non-woven top layer adjacent to said middle layer and opposite said substrate relative to said middle layer, said top layer comprising organic fibers or a substantially uniform mixture of organic and inorganic fibers with the organic fibers comprising more than 10 percent of said uniform mixture, said fibers of said top layer being of sufficient average length whereby a sufficient portion of said fibers of said top layer interlock with said first substrate as a result of needling said fibers through the top layer, middle layer and first substrate to provide a substantially stable structure, said fibers of said top layer being of sufficient strength and present in sufficient quantity to provide said top layer with a substantially uniform cross-sectional area, said needled structure having a punch density of between about 400 to 3,000 penetrations per square inch.

Claim 24

A method for the production of a moldable fibrous composite structure, said method comprising the steps of: introducing a first needleable substrate, said substrate defining a base side opposite a face side, introducing a middle layer comprising mineral fibers of sufficiently short length to substantially preclude interlocking of any of said mineral fibers with other fibers of said structure and to provide said structure with a desired degree of flexibility onto the face side of said first needleable substrate, said middle layer of mineral fibers initially lacking structural integrity, said mineral fibers being present in a quantity sufficient to impart desired heat and sound insulating properties to said structure, introducing a non-woven top layer comprising organic fibers or a substantially uniform mixture of more than ten percent organic fibers with inorganic fibers onto said middle layer whereby said middle layer is disposed between said first substrate and said top layer to form a precursor composite, said fibers of said top layer being of a sufficient average length whereby a sufficient portion of said top layer fibers interlock with said first substrate upon needling said fibers completely through the top layer, middle layer and first substrate to provide a substantially stable structure, said fibers of said top layer being of sufficient strength and present in sufficient quantity to provide said top layer with a substantially uniform cross-sectional area upon subsequent needling of said precursor composite, and thereafter needling said precursor composite by driving the needles completely through the top layer and middle layer and into the first substrate whereby said structure having a punch density of between about 400 to 3,000 penetrations per square inch is attained and said structure being producible on a continuous basis.

Claim 25

A method for the production of a moldable fibrous composite structure, said method comprising the steps of: introducing a first needleable substrate, said substrate defining a base side opposite a face side, introducing a middle layer comprising mineral fibers of sufficiently short length to substantially preclude interlocking of any of said mineral fibers with other fibers of said structure and to provide said structure with a desired degree of flexibility onto the face side of said first needleable substrate, said middle layer of mineral fibers initially lacking structural integrity, said mineral fibers being present in a quantity sufficient to impart desired heat and sound insulating properties to said structure, introducing a non-woven top layer comprising organic fibers or a substantially uniform mixture of more than ten percent organic fibers with inorganic fibers onto said middle layer whereby said middle layer is disposed between said first substrate and said top layer to form a precursor composite, said fibers of said top layer being of a sufficient average length whereby a sufficient portion of said top layer fibers interlock with said first substrate upon needling said fibers completely through the top layer, middle layer and first substrate to provide a substantially stable structure, said fibers of said top layer being of sufficient strength and present in sufficient quantity to provide said top layer with a substantially uniform cross-sectional area upon subsequent needling of said precursor composite, and thereafter needling said precursor composite by driving the needles completely through the top layer and middle layer and into the first substrate whereby said structure having a punch density of between about 400 to 3,000 penetrations per square inch is attained and said structure being producible on a continuous basis.