Patent ID: 8668758

Claim:
A tackified air filtration media having improved stiffness and foldability comprising a thermally bonded nonwoven web comprising a generally homogeneous mixture of at least two types of fibers, the web comprising about 10% to about 90% by weight of a first type of fibers having a length of about 6 mm to about 200 mm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, about 5% to about 70% by weight of a second type of fibers having a length of about 6 mm to about 200 mm, and a denier of 5 or less, about 0% to about 40% by weight of a third type of fibers having a length of about 6 mm to about 200 mm and a denier of 8 or more; the nonwoven web having a basis weight in the range of about 90 gsm to about 370 gsm, preferably between 120-275 gsm, and a thickness of about 1.0 mm to about 6.4 mm; and from about 0.5 percent to about 30 percent by weight of the nonwoven web of a tackifier on fibers of the air filtration media, the nonwoven web being configured for use as self-supporting air filtration media and having a Gurley stiffness of at least 2930 mg when measured in the machine direction.