Filtration Article With Fluoropolymer Knit
AssigneeEntegris, Inc.
InventorsEric Keith Propst, Steven H. Speck
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Abstract
Disclosed is a filtration article comprising a first layer comprising porous PTFE for fluid filtration (e.g., a PTFE membrane), and a second layer comprising strands of fluoropolymer fibers arranged to form a stable knit. The knit layer comprises interlocking regions that are each defined by corresponding sets of at least two interlocking loop portions of the fluoropolymer fiber strands. In filtration article embodiments, the fluoropolymer fiber strands may be twisted and/or have a rounded outer configuration. The knit layer provides improved dimensional stability as a support layer for the filtration layer and/or as a drainage layer.
Claims41
A filtration article for filtration of particles from a fluid stream, comprising:
- a first layer, positionable across a fluid stream, comprising a porous PTFE membrane for filtering particles from the fluid stream;
- and
- a second layer, positionable across said fluid stream to provide for at least one of drainage of and support of said first layer, comprising a plurality of strands of fluoropolymer fibers arranged to form a knit having a plurality of interlocking regions that are each defined by corresponding different sets of at least two interlocking loop portions of said plurality of strands of fluoropolymer fibers, wherein said plurality of interlocking regions of the knit define a plurality of wales and a plurality of courses, and wherein for at least a first portion of said plurality of strands each strand comprises different loop portions that partially define different, alternating ones of said plurality of interlocking regions located along at least two different ones of said plurality of wales.
A method for filtering particles from a fluid stream, comprising:
- filtering particles from a fluid stream having a fluid pressure utilizing a porous PTFE membrane positioned across the fluid stream;
- and,
- supporting said porous PTFE membrane against a fluid pressure load applied by the fluid stream utilizing a stable knit layer positioned downstream of the porous PTFE membrane.
Dependencies are inferred from the claim text.