Low density fibrous sheet material

Claim 1

A method of forming a low density fibrous sheet material which method comprises forming an aqueous slurry that comprises fibers, a soluble salt selected from the group consisting of aluminum salts, ferric salts and stannic salts, and a sufficient amount of an alkaline hydroxide to provide a slurry pH within the range of from about 6 to about 10, said alkaline hydroxide serving to convert said soluble salt to a water insoluble hydroxide; depositing a synthetic rubber binder on said fibers to form rubber-coated fibers; adding the resulting fibrous slurry to a solution of a foamable detergent in water; foaming the resulting mixture, which has a consistency of from about 4 to about 15 weight percent solids, to homogeneously suspend the fibrous slurry therein; and drying the mixture to thereby form the low density fibrous material wherein from about 5 to about 50 parts by weight of synthetic rubber binder are employed for every 100 parts of fiber.

Claim 2

A method of forming a low density fibrous sheet material which method comprises forming an aqueous slurry that comprises fibers, a soluble salt selected from the group consisting of aluminum salts, ferric salts and stannic salts, and a sufficient amount of an alkaline hydroxide to provide a slurry pH within the range of from about 6 to about 10, said alkaline hydroxide serving to convert said soluble salt to a water insoluble hydroxide; depositing a synthetic rubber binder on said fibers to form rubber-coated fibers; adding the resulting fibrous slurry to a solution of a foamable detergent in water; foaming the resulting mixture, which has a consistency of from about 4 to about 15 weight percent solids, to homogeneously suspend the fibrous slurry therein; and drying the mixture to thereby form the low density fibrous material wherein from about 5 to about 50 parts by weight of synthetic rubber binder are employed for every 100 parts of fiber.

Claim 8

A method of forming a low density fibrous sheet insulation material which method comprises forming an aqueous slurry that comprises mineral wool fibers, a soluble salt selected from the group consisting of aluminum salts, ferric salts and stannic salts, and a sufficient amount of an alkaline hydroxide to provide a slurry pH within the range of from about 6 to about 10, said alkaline hydroxide serving to convert said soluble salt to a water insoluble hydroxide; depositing a synthetic anionic-type rubber latex binder on said fibers to form rubber-coated fibers; adding the resulting fibrous slurry to a solution of a foamable detergent in water; foaming the resulting mixture, which has a consistency of from about 5 to about 15 weight percent solids, to homogeneously suspend the fibrous slurry therein; forming the mixture into sheets and drying the sheets to thereby form the low density fibrous insulation sheet material wherein from about 5 to about 5 parts by weight of synthetic rubber binder are employed for every 100 parts of fiber.

Claim 9

A method of forming a low density fibrous sheet insulation material which method comprises forming an aqueous slurry that comprises mineral wool fibers, a soluble salt selected from the group consisting of aluminum salts, ferric salts and stannic salts, and a sufficient amount of an alkaline hydroxide to provide a slurry pH within the range of from about 6 to about 10, said alkaline hydroxide serving to convert said soluble salt to a water insoluble hydroxide; depositing a synthetic anionic-type rubber latex binder on said fibers to form rubber-coated fibers; adding the resulting fibrous slurry to a solution of a foamable detergent in water; foaming the resulting mixture, which has a consistency of from about 5 to about 15 weight percent solids, to homogeneously suspend the fibrous slurry therein; forming the mixture into sheets and drying the sheets to thereby form the low density fibrous insulation sheet material wherein from about 5 to about 5 parts by weight of synthetic rubber binder are employed for every 100 parts of fiber.