Patent ID: 8283266

Claim:
A fibrous nonwoven mat having a basis weight of 2.3 to about 2.6 lbs/100 sq. ft., a thickness in the range of about 38 to about 48 mils, high flame resistance and unexpected excellent tensile strength, flex and recovery properties after scoring and folding and being suitable for use as a scored and folded fibrous nonwoven mat for vertical webs spanning between an exposed mat and a backer mat in a compressible ceiling tile because of the fibrous nonwoven mat having the ability, after being scored, folded, and compressed, to spring back to the original shape and orientation, the fibrous nonwoven mat comprising a blend of fibers comprising about 88 to about 92 weight percent chopped glass fibers having a diameter in the range of about 13 to about 17.5 microns and a length in the range of about 0.7 to about 1.1 inches and about 8 to about 12 percent man-made polymer fibers selected from the group consisting of polyester, polypropylene, nylon, PBT, polyacrynitrile, and polybenzimidizole in the fibrous nonwoven mat, the blend of fibers in the being bound together by a binder that is at least partially cured and consists essentially of, before drying and curing, a homopolymer or a copolymer of polyacrylic acid and a polyol, with or without a polycarboxy polymer, the binder being present in the mat in an amount of about 25+/31 5 wt. percent of the fibrous nonwoven mat, the fibrous nonwoven mat having a Taber Stiffness of at least about 50 gram centimeters and passing the National Fire Protection Association's (NFPA) Method #701 Flammability Test.