Porous PTFE membrane
AssigneeDonaldson Company, Inc.
InventorsAnil Suthar, Richard Brandimarte, Robert J. Pannepacker, Jr., Stuti S. Rajgarhia
Life of this patent
Estimating the term…
Abstract
A porous polytetrafluoroethylene (PTFE) membrane including a nonwoven web having a microstructure of substantially only microfibrils fused at crossover points, said membrane having a percent balance of orthogonal dimensions that is within 10%.
Claims20
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.
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, the 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 membrane has a thickness of 1 micrometer to 3.8 micrometers.
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, the 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 membrane has a thickness of 7.8 micrometer to 10 micrometers.
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, the 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 5% of the tensile peak stress in the cross direction.
Dependencies are inferred from the claim text.