Abstract: A wet-laid dual-layer air filtration media having a thin, lightweight top layer and a bottom layer is provided. The novel media includes a large diameter synthetic polymeric fiber in the top layer that deforms plastically and retains cohesion as a single object, while minimizing use of frangible components that become airborne upon handling. The novel media provides improved high dust holding capacity, while typically maintaining an overall lower basis weight than heretofore available media.

Abstract: A pleatable, high efficiency composite gas filtration media is provided. The media includes an essentially boron free chopped strand glass backer layer and media layer comprising a synthetic material. The composite media exhibits excellent pleatability, low boron out gassing, and low organic out gassing, with filtration performance comparable to existing commercial membrane composites.

Abstract: A pleatable, high efficiency composite gas filtration media is provided. The media includes an essentially boron free chopped strand glass backer layer and media layer comprising a synthetic material. The composite media exhibits excellent pleatability, low boron out gassing, and low organic out gassing, with filtration performance comparable to existing commercial membrane composites.

Abstract: A composite is provided which has improved transverse structural integrity and flexibility and suitable for use in high temperature and high stress environments. The composite has randomly oriented high temperature resistant inorganic fibers interlocked together into a shape sustaining paper with a transverse thickness of from about 0.005 to 0.5 inch. A transverse strength providing high temperature resistant, flexible fabric, made of inorganic fibers is disposed upon at least one of the surfaces of said paper. An organic adhesive is disposed between the paper and the fabric and flexibly bonds the paper to the fabric to form a composite. The composite is sufficiently flexible that it may be folded or pleated without breaking and is capable of being used at high temperatures and at high transverse stresses without rupturing.