High stiffness nonwoven filter medium
AssigneeKimberly-Clark Worldwide, Inc.
InventorsDavid Grant Midkiff, James Richard Neely
Life of this patent
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Abstract
A filter medium having high stiffness is provided. The filter is a nonwoven web of conjugate fibers which has a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80. The conjugate fibers may be polyolefin, more particularly polypropylene and polyethylene in a side-by-side configuration. The medium may be made into a filter by conventional means such as pleating. Such filters are useful in HVAC systems and transportation cabin air filtration.
Claims19
A filter medium comprising a nonwoven web of conjugate fibers having a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80.
A filter medium comprising a nonwoven web of crimped polypropylene/polyethylene side-by-side conjugate fibers having a basis weight between about 68 gsm and about 340 gsm and having a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80, formed by a process wherein said web is subjected to hot air knife treatment, through-air bonding and electret treatment wherein said electret treatment imparts a charge to said fibers.
A pleated filter comprising a nonwoven web of crimped polypropylene/polyethylene side-by-side conjugate fibers having a basis weight between about 68 gsm and about 340 gsm, a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80, formed by a process wherein said web is subjected to hot air knife treatment immediately after formation, through-air bonding after said hot air knife treatment, electret treatment to impart a charge to said fibers after said through-air bonding, and wherein said web is pleated to form a filter.
Dependencies are inferred from the claim text.