Nonwoven fibrous insulation material

A nonwoven composite insulation material comprising:

• a discrete layer consisting essentially of mineral wool fibers, said layer having a preselected thickness, said mineral wool fibers of said layer being in an unbonded state;
• at least one carrier web for bonding together said mineral wool fibers;
• said carrier web including an admixture of inorganic fibers and organic fibers;
• said inorganic fibers and said organic fibers being blended to form a nonwoven structure with said organic fibers thereof comprising about 1% or less by weight of said composite insulation material;
• said carrier web being positioned with said layer of said mineral wool fibers;
• and
• said carrier web being needle punched to said layer of said mineral wool fibers to interlock said inorganic fibers and said organic fibers of said carrier web with said mineral wool fibers so as to bond together said mineral wool fibers and form said nonwoven composite insulation material.

A process for making a nonwoven fibrous material comprising the steps of:

• blending inorganic fibrous material in a concentration by weight of at least about 90% with organic fibrous material to form at least one composite nonwoven carrier web of carrier fibers having a preselected thickness and density;
• positioning said carrier web in contact with a layer of inorganic fibers, said layer comprising an unstructured concentration of said inorganic fibers of a preselected thickness and density;
• and
• needle punching said carrier web to advance said carrier fibers into interlocking relation with said inorganic fibers to bond together said inorganic fibers to form said nonwoven fibrous material having a preselected thickness and density and a content of said organic fibrous material of about 1% or less by weight.

A process for making a carrier web comprising the steps of:

• providing a plurality of inorganic fibers;
• providing a plurality of organic fibers;
• coating said inorganic fibers to increase the surface friction of said inorganic fibers;
• and
• blending said coated inorganic fibers in a preselected concentration with said organic fibers to form said carrier web having a preselected thickness and density and containing about 10% or less by weight of said organic fibers.