A spunbond non-woven fabric includes a thermoplastic continuous filament. Bending resistance in a machine direction of the spunbond non-woven fabric is 40 mN or more and 80 mN or less, the spunbond non-woven fabric includes a nonbonded projected part and a bonded recessed part, and in a non-woven fabric cross-section, a thickness from one surface to another surface of the projected part is determined to be t.sub.A, a thickness from one surface to another surface of the recessed part is determined to be t.sub.B, and respective distances from one surface of the projected part to one surface of the recessed part are determined to be t.sub.C and t.sub.D (t.sub.C<t.sub.D), and the spunbond non-woven fabric has a relation represented by formulas (1) and (2) below:

0.5≤1−t.sub.B/t.sub.A<1.0   (1)

0.65<t.sub.C/t.sub.D<1.0   (2).

A filter cartridge configured to be removably positionable within an inner opening of a housing, wherein the filter cartridge includes a media pack having an inlet end, an outlet end, and an outer surface having an outer peripheral shape, at least one of: (a) a frame member at least partially surrounding the media pack, the frame member including a frame wall having a shape that is different from the outer perimeter shape of the media pack; and (b) a shell at least partially surrounding the media pack, the shell including a shell wall having a shape that is different from the outer perimeter shape of the media pack, and a sealing member extending at least partially around the inlet end of the media pack, wherein the sealing member comprises a pinch seal portion that is spaced from the outer surface of the media pack.

A filter element is provided that is preferably a side entry air filter having an air filter media pack, a housing seal and a frame that has a clamping projection, a pivot projection and/or guide members. The clamping projection can define a non-linear bearing surface that may be chevron shaped to provide for interface and potential alignment benefits. The housing seal may be a wave seal that undulates.

An air purifier includes a housing, a first blower, a second blower, and a filter. The housing has a cavity inside, an inlet and an outlet. The first blower has a first fan in the housing. The second blower has a second fan in the housing. The second blower faces the first blower in an opposing direction. The inlet is located between the first blower and the second blower in the opposing direction. The inlet opens in a direction intersecting the opposing direction. The first fan of the first blower and the second fan of the second blower generate airflow such that air flows into the cavity through the inlet, and flows from the cavity through the filter to the outlet.

A pleated multilayer air filter assembly including a primary filtration layer and a prefilter layer that are bonded to each other and are co-pleated with each other. The primary filtration layer includes meltblown electret fibers. The prefilter layer includes meltspun, spunbonded electret fibers that comprise a radially outer surface comprising polymethylpentene. The ratio of Effective Fiber Diameter of the fibers of the primary filtration layer to Effective Fiber Diameter of the fibers of the primary filtration layer is at least 1.5.

Described are wound-pleated filters and methods of preparing and using these filters.

A spunbond non-woven fabric includes a nonbonded projected part and a bonded recessed part. Bending resistance in a machine direction of the spunbond non-woven fabric is 20 mN or more and 40 mN or less, and in a non-woven fabric cross-section, a thickness from one surface to another surface of the projected part is determined to be t.sub.A, a thickness from one surface to another surface of the recessed part is determined to be t.sub.B, and respective distances from one surface of the projected part to one surface of the recessed part are determined to be t.sub.C and to (t.sub.C<t.sub.D), and the spunbond non-woven fabric has a relation represented by formulas (1) and (2) below:

0.5≤1−t.sub.B/t.sub.A<1.0  (1)

0.35<t.sub.C/t.sub.D<0.65  (2).

A filter for filtering particulates from a fluid stream includes a filter element, a first end cap, a second end cap, and a wrap. The end caps are respectively secured to the ends of the filter element to form a fluid tight seal therebetween. At least one of the end caps defines an opening therethrough in fluid communication with the interior passage of the filter element. The wrap is in the form of a strip secured to at least the filter element. The wrap comprises a conductive layer comprising an electrically-conductive material. The wrap is wrapped around the filter element such that at least forty percent of the outer surface area is covered by the conductive layer.

A filter system for a vacuum cleaner is disclosed. The system comprises a housing reconfigurable relative to a bin between an operative configuration in which the housing is disposed upon the bin so that dirt separated from dirt-laden air can collect in the bin, and an idle configuration in which the housing is removed from the bin. The housing comprises an inlet for receiving dirt-laden air into the housing, an outlet via which cleaned air can exit the housing. The system further comprises first filtering means and second filtering means disposed within the housing, the first filtering means being positioned upstream of the second filtering means. The first and second filtering means comprises a filter medium configured to separate dirt from the dirt-laden air passing from the inlet to the outlet through the filter medium. The system further comprises filter cleaning means for removing dirt from the filter medium of the first filtering means when the housing is configured at least in the operative configuration.

Disclosed herein are systems and methods for treating air.