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US 4,732,675 AGranted
Density gradient filtration media
AssigneeMcNeilab, Inc.
InventorsAnthony Badolato, Melissa A. Prince
Life of this patent
Estimating the term…
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AssigneeMcNeilab, Inc.
InventorsAnthony Badolato, Melissa A. Prince
Estimating the term…
A filtration unit comprising a filtration media subunit secured in an outer frame. The subunit comprises a fibrous filtration media enclosed in an inner frame having an upstream frame element and a downstream frame element. Each frame element has longitudinal and transverse struts and the intersection of these struts is in a single plane on the side of the frame elements which contact the filtration media. In one embodiment the filtration unit is enclosed in a sock of knit fabric; in another embodiment, there is a piece of knit fabric between the outer frame and the downstream frame element of the inner frame. The longitudinal struts may have portions which are perpendicular to and project beyond the principal plane of the periphery of the downstream frame element. If such perpendicularly projecting portions are provided, they are preferably arcuate in configuration.
Filtration media comprising an upstream fibrous layer. at least one downstream fibrous layer said upstream layer including synthetic fibers having a denier in the range of 4 to 8, said layers having a weight ranging from about 6.5 ounces per square yard to about 11.5 ounces per square yard, a thickness ranging from about 0.035 inch to about 0.080 inch, a mean pore size ranging from about 40-80 microns, and a bubble point of at least about 2.5 inches of water, said downstream fabric including synthetic fibers having a denier in the range of 22-28, said downstream fabric having a weight ranging from about 6.5 ounces per square yard to about 11.0 ounces per square yard, a thickness in the range of about 0.030 inch to about 0.070 inch, a mean pore size in the range of about 35-60 microns, and a bubble point of at least about 4.0 inches of water;
Dependencies are inferred from the claim text.