	US 12,318,722 B2
	Porous PTFE membrane
Anil Suthar, Eden Prairie, MN (US); Richard Brandimarte, Bensalem, PA (US); Robert J. Pannepacker, Jr., Oreland, PA (US); and Stuti S. Rajgarhia, Woodbury, MN (US)
Assigned to Donaldson Company, Inc., Bloomington, MN (US)
Appl. No. 17/414,908
Filed by Donaldson Company, Inc., Minneapolis, MN (US)
PCT Filed Dec. 16, 2019, PCT No. PCT/US2019/066646 § 371(c)(1), (2) Date Jun. 16, 2021, PCT Pub. No. WO2020/131752, PCT Pub. Date Jun. 25, 2020.
Claims priority of provisional application 62/780,776, filed on Dec. 17, 2018.
Prior Publication US 2022/0062806 A1, Mar. 3, 2022
Int. Cl. B01D 39/16 (2006.01); B01D 69/02 (2006.01); B01D 71/36 (2006.01)

CPC B01D 39/1692 (2013.01) [B01D 69/02 (2013.01); B01D 71/36 (2013.01); B01D 2239/025 (2013.01); B01D 2239/0618 (2013.01); B01D 2239/1216 (2013.01); B01D 2239/1233 (2013.01); B01D 2239/1291 (2013.01); B01D 2325/0281 (2022.08); B01D 2325/04 (2013.01); B01D 2325/24 (2013.01)]

20 Claims

1. A porous polytetrafluoroethylene membrane consisting of polytetrafluoroethylene, the porous polytetrafluoroethylene membrane being a nonwoven web having a microstructure of microfibrils fused at crossover points with less than 100 nodes per 100 μm², said membrane having a tensile peak stress in a machine direction and a tensile peak stress in a cross direction, wherein the tensile peak stress in the machine direction is within 10% of the tensile peak stress in the cross direction, and wherein the tensile peak stress in the machine direction and the tensile peak stress in the cross direction is up to 130 MPa at room temperature.