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US 4,801,383 AGranted
Selective twist filtration roving
AssigneeMemtec North America Corporation
InventorsMichael A. Hoffmann, Robert J. Schmitt
Life of this patent
Estimating the term…
Abstract
This invention relates to a filtration roving with the cross section of the roving exhibiting portions more tightly twisted than the remainder of the roving.
Claims11
A filter comprising
- rigid pervious core means through which fluid to be filtered can flow,
- filter media means for filtering the fluid, the filter media means covering a portion of said core means,
- the filter media means comprising filtration roving consisting of a twisted unitary strand which, in crosssection, exhibits portions more tightly twisted than the remainder of the roving.
A filter comprising
- rigid pervious core means through which fluid to be filtered can flow,
- filter media means for filtering the fluid, the filter media means covering a portion of said core means, and
- the filter media means comprising a twisted unitary strand filtration roving in which selected fibers comprising selected portions of the roving are subjected to greater negative pressure between spinning drums used to make the roving than other fibers comprising the non-selected portions of the roving.
In a filter comprising a rigid, pervious core and filter media surrounding at least a portion of said core, said filter media composed of filtration roving wound around the core,
- the improvement wherein said roving consists of a twisted unitary strand and, in cross-section, is characterized by an outer region of comparatively bulky twisted fiber and an inner region formed of fibers more tightly twisted than said outer region fibers.
Dependencies are inferred from the claim text.