Abstract: There is provided a vacuum cleaner filer bag including at least two sidewalls which sidewalls are joined by seams. At least one first sidewall comprises a film laminate of a heat sealable film layer and a film support layer. At least one second sidewall comprises a filter laminate comprising at least a synthetic fiber filter layer and synthetic fiber support layer where the at least one first sidewall is joined to adjacent sidewalls by thermal seams. The filter layer is preferably a high efficiency microfiber filter media which provides HEPA level performance for the vacuum cleaner bag.

Abstract: A high efficiency filtration medium comprised of a nonwoven filter web of electret charged fibers of a nonconductive thermoplastic resin having a resistivity greater than 10.sup.14 ohm-cm, preferably polypropylene. The nonwoven filter web has a basis weight (BW) of less than 60 grams/m.sup.2, an effective fiber diameter (EFD) of less than 5 microns and a penetration (PEN) of less than 0.03%, wherein the ratio);BW/(EFD.PEN)is greater than 200. The invention filter medium can be easily used in applications requiring HEPA performance at relatively low pressure drops.

Abstract: An electret filter media, and mask, that is made of a nonwoven web of thermoplastic microfibers. The thermoplastic microfibers are of substantially the same composition, are nonconductive, and have an effective fiber diameter less than about 15 micrometers. The nonwoven web also has sufficient unpolarized trapped charge to exhibit an initial filtration quality factor of at least 0.31 when measured under the DOP Penetration and Pressure Drop Test.

Abstract: A separation plate (10) includes a first surface (10a) and an opposing second surface. A plurality of teardrop-shaped virtual impactor projections (12) are provided on the first surface, preferably in a plurality of rows (13a, 13b, 13c). Each projection includes a convex leading profile (18) facing a fluid stream (16), and two concave side surfaces (19) that are positioned to define a tapered downstream portion. The convex leading profile may include a concave portion (20). The concave portion defines a virtual impact void therethrough. The virtual impact void defines a terminal end of a passageway that extends through the separation plate to communicate with the second surface. When particle-laden fluid is caused to flow along the first surface, a major portion of the fluid containing a minor portion of particles flows around the teardrop-shaped virtual impactor projections along the first surface.

Abstract: A plurality of micropillars (2) arranged in a plurality of rows (4, 6, 8) are provided. When a particle-laden fluid stream is caused to flow through the micropillars, at least a portion of the particles impacts and becomes deposited on the micropillars' surfaces while the fluid stream is deflected aside. The deposited particles may subsequently be collected.

Abstract: An improved gas filtration media with a lower initial pressure drop and increased dirt holding capacity includes a fibrous mat of randomly oriented meltblown polymeric fibers made from a polymer with between 0.2% and 10.0% by weight of: a) a nucleating agent to increase the rate of crystallization of the polymer forming the fibers and improve the heat sealability of media made from the fibers and/or b) an electrostatic charging enhancer to reduce surface tension of the polymer and inter-fiber attraction, as the fibers are cooled during formation and collection the fibers, to thereby facilitate the formation of the fibrous mat with discrete fibers. Preferably, the polymer is polypropylene, the nucleating agent is bis-benzylidene sorbitol, and electrostatic charging enhancer is a fatty acid.

Abstract: There is provided an air delivery device and method of moving and filtering air. The air delivery device comprises a housing having an air inlet and an air outlet. Between the air inlet and the air outlet is located an air delivery fan having at least two rotating air moving elements, the rotating air moving elements intersects the flow of air between the air inlet and the air outlet and establishes a higher pressure zone at the air outlet relative to the air inlet. The air delivery fan further comprises at lest one filter element, having at least one upstream filter face and at least one downstream filter face, defining at least one primary flow channel, and rotating along the same axis of rotation as the air moving elements and preferably forming the air moving elements at least in part.

Abstract: There is provided a moving sorbent filter within an air delivery device. The air delivery device has a housing having an air inlet and an air outlet, between the air inlet and the air outlet is located an air delivery fan having at least two rotating air moving means. The rotating air moving means intersect the flow of air between the air inlet and the air outlet and establish a higher pressure zone at the air outlet relative to the air inlet. The air delivery fan further comprising a moving porous sorbent filter formed of at least one sorbent filter element. The sorbent filter has at least one air passage allowing substantially unimpeded airflow into and through the sorbent filter.

Abstract: A filtration system that rotates in conjunction with a blower wheel, and a method of attaching the same. The blower wheel typically has a plurality of fan blades arranged in a spaced relationship radially around a blower cavity to define a flow path extending radially outward from the blower cavity through the fan blades when the blower wheel is rotating. The filtration system includes a filter cartridge releasably attachable to the blower wheel in an engaged configuration. The filter cartridge includes a filter medium defining a generally center opening and a filter surface configured to be positioned generally adjacent to the fan blades and to extend across at least a portion of the flow path. In one embodiment, a plurality of flow passages extending through the filter medium.

Abstract: A frameless electrostatic air filter used in heating and air conditioning systems includes a plurality of filter media layers and an internal support grill and has no external support grill or frame. The frameless electrostatic air filter has an internal support grill to support the filter media layers and a fabric edging that is secured in place all the way around the edge of the frameless electrostatic air filter. The center of the frameless electrostatic air filter is secured with a plastic rivet. The frameless electrostatic air filter seats and seals tight to the inside lip of filter receptacles.

Abstract: Filter assemblies are disclosed that include a pleated web in which the pleats are connected to each other to provide support for the filter media during use. The interconnected pleats preferably form an array of openings facing the upstream side of the filter assembly when subjected to fluid pressure during use. In addition, the preferred filter media also includes an array of pockets located behind each of the points at which the pleats are connected. By connecting the pleats to form arrays of openings and pockets during use, the filter assemblies provide a structure that deforms in a predetermined, acceptable manner without the need for external support structure to support the pleats.

Abstract: A frameless electrostatic air filter used in heating and air conditioning systems includes a plurality of filter media layers and an internal support grill and has no external support grill or frame. The frameless electrostatic air filter has an internal support grill to support the filter media layers and a fabric edging that is secured in place all the way around the edge of the frameless electrostatic air filter. The center of the frameless electrostatic air filter is secured with a plastic rivet. The frameless electrostatic air filter seats and seals tight to the inside lip of filter receptacles.

Abstract: Electret filter media comprising a fibrous web of a blend of a thermoplastic resin and at least one compound or oligomer that enhances the web's electret properties.

Abstract: Disclosed is an improved filter formed from a non-dielectric material which has been coated with a dielectric material and electret treated by, for example, DC corona discharge treatment. Also disclosed is a method for the formation of the filter.

Abstract: An electrostatic filter includes a fibrous component including a mixture of wool and synthetic fibers and a resinous component including a perfluoroalkyl acrylate copolymer resin and a p-tert-butylphenol formaldehyde resin, which resinous component is adhering to the fibrous component, both of the fibrous substrate component and the resinous component being in electrostatically charged conditions.

Abstract: Proposed is an electret fiber which is an insolubilized polyvinyl alcohol fiber containing 0.05 to 0.5% by weight of tourmaline particles having a particle diameter not exceeding 0.3 .mu.m. The electret fiber is effective for invigoration of human body by promoting blood circulation and also effective for decreasing the BOD value of sewage water by activating the bacteria in the activated sludge. The electret fiber is prepared by spinning a spinning solution of the polyvinyl alcohol containing the tourmaline particles into the form of a fiber which is then subjected to an insolubilization treatment by a heat treatment, formalization with formaldehyde or acetalization with glutaraldehyde.

Abstract: An HVAC filter having a pleated paper filter and a plastic pre-filter, the filter and pre-filter are mounted in a parallel relation in the frame. The plastic pre-filter includes a plastic mesh having a plurality of openings, and an irregular surface on the inlet side to prevent matting of filtered material.

Abstract: A sterilizable nonwoven material which is subjected to electreting, and more particularly electrostatic electreting is provided. The nonwoven materials may include laminate nonwovens wherein one or more layers are subjected to electreting. The nonwoven material(s) may also be treated with an antistatic material before or after subjecting the same to electreting.

Abstract: A plasma sterilizable fabric which is subjected to charging, for example electrostatic charging, is provided. Plasma sterilizable fabrics may include nonwovens and laminate nonwovens. The plasma sterilizable fabrics may also be treated with an antistatic material before or after subjecting the same to charging.

Abstract: A ceiling fan for cleaning air in a room wherein each blade of the ceiling fan has a cavity open to the top and bottom surfaces of each fan blade and a filter unit in each of the cavities but within the confines of the fan blade such that, when the ceiling fan is operated, the airflow created by the ceiling fan will be forced through the filter unit from the bottom surface through to the top surface, wherein the filter units can collect airborne particles.

Abstract: There is provided a nonwoven electret fiber filter formed with a nonwoven web of electret fibers needle-punched to an open scrim support. The scrim support material has individual discrete open areas with an average cross-sectional area as viewed from the plane of the filter media of at least 0.25 mm.sup.2, preferably 1.0 mm.sup.2, and a pressure drop across the scrim support, without the filter web, of less than 1.5 mm H.sub.2 O measured at 98.4 meters/min gaseous face velocity. The resulting filter has enhanced lifetimes, a low pressure drop and high filtration efficiencies.

Abstract: An air filtration or fluid treatment system includes a nonwoven filter media or mat (10) formed from a plurality of elongated generally hollow fibers (20) each having an internal cavity (22) which has an opening (24) to the fiber surface and each retaining within the internal cavity a large number of relatively small solid particles (18) which interact with the air or other fluid stream to be treated. The solid adsorbent particles (18), such as activated carbon, are permanently entrapped within the longitudinal cavities (22) of the fibers (20) without the use of an adhesive or without being embedded onto or within the polymer fiber.

Abstract: A non-wovens fabric of electret fibers having an improved charge stability and comprising materials which chiefly comprise a fiber-forming addition or condensation polymer and 0.01 to 30% by weight (preferably 0.01 to 10, in particular 0.1 to 5, % by weight), based on the weight of the material, of organic or organometallic charge control agents, wherein the non-woven fabric comprises at least two types of electret fiber which are made of different materials which differ from one another in that they comprise different fiber-forming addition or condensation polymers and if appropriate also different charge control agents is described.

Abstract: A filter has a series of porous, compressible filter elements sealed at their outer edge by a collar of silicone rubber that is flowed into the filter elements. The collar seals with an annular recess around the inside of a filter housing so that flow through the housing is confined to the filter elements without any compression of them.

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.

Abstract: An HVAC filter having a pleated paper filter and a plastic pre-filter, the filter and pre-filter are mounted in a parallel relation in the frame. The plastic pre-filter includes a plastic mesh having a plurality of openings, and an irregular surface on the inlet side to prevent matting of filtered material.

Abstract: A filter apparatus for mounting over an opening at an end of a forced air system duct has a filter frame with sidewalls between open front and back ends and a channel which opens inwardly of the sidewalls. At the front end is a sheet of preferably self charging electrostatic washable filter material behind a grill, both of which are peripherally disposed within the channel and are sized and sufficiently flexible so as to be removably insertable into the channel. A second sheet of a second filter material, preferably including activated charcoal, may be disposed in the channel behind the first sheet of filter material. The filter material may be made of a woven polypropylene and the sheet may have heat sealed finished edges. A wall mount having a support frame for mounting on a wall around the opening which extends through the wall is sized and operable to support the filter frame. The support frame may be mounted to a wall.

Abstract: The flexible filter element (12) of the filter (10) is pleated in a zig-zag-shaped configuration and has its longitudinal edges (24) connected to support elements (26). Each of the support elements (26) comprises a plurality of support members (40) arranged beside one another and being interconnected by a continuous flange (28). The support elements (26) as well as the rest of the filter element (12) are made of a plastic material. The strength of the flanges (28) is selected in such a manner that the support members (40) are flexible relative to each other which is possible by elastic or plastic deformation of the support elements (26) in the region of the flanges (28), particularly in that region of the flanges (28) wherein these flanges connect adjacent support members (40). The filter (10) can be produced as a filter element (12) extending in a linear plane, which, because of its flexibility, can be deformed while being mounted and/or remain deformed in its mounted condition.

Abstract: There is provided a vacuum cleaner filter medium which is a nonwoven spunbond web of conjugate spunbond fibers. The web has a Frazier permeability of at least 250 CFM, an NaCI efficiency of at least 65 percent, a Gurley Stiffness of at least 20 mg, and a pressure drop of 0.5 or less mm H.sub.2 O. The conjugate fibers are made from polymers, more particularly polyolefins, still more particularly polypropylene and polyethylene in a side-by-side configuration. The filter medium is treated by a hot-air knife and through-air bonded during the production process. The medium is also electret treated. The medium has sufficient stiffness to be converted into a filter by conventional techniques. While this invention is directed mainly to air purification and filtration, other gasses may be filtered as well.

Abstract: A vacuum cleaner having a reduced velocity chamber with a high velocity air inlet, an electric motor, a rotary mechanism driven by the motor for creating a vacuum in the chamber, an outlet for exhausting air from the chamber, which air flows in a selected path from the air inlet, through the chamber and out the air exhaust outlet and a disposable porous sheet filter layer in the chamber for removing solids particles from the air. The vacuum cleaner also has a fiber filter between the filter layer and the motor where the fiber filter has an electrically charged non-woven material for removing very fine air particles in the chamber, intersecting the air path and generally coterminous with the disposable filter layer.

Abstract: There is provided a vacuum cleaner bag with high fine particle removal efficiency under normal and shock loading conditions, shock loading including a short term challenge with high particle concentrations (e.g., when a vacuum is used to pick up a pile of debris). The bag also exhibits high loading capacity without significant loss in pressure drop. The bag includes an outer support layer, a fibrous filter layer that is charged to create electrets, and an inner diffusion layer that is substantially unbonded to the filter layer, except at necessary bag seams required for assembly of the filter bag.

Abstract: A nonwoven disposable face mask includes a filtration layer formed of a plurality of thermoplastic microfine meltblown microfibers having an average fiber diameter of less than 1.5 microns. The filtration layer also has a basis weight of less than ten grams per square meter. The resultant face mask provides improved wearer comfort and barrier and filtration properties.

Abstract: An electret filter media includes an additive or mixtures thereof that enhance the charge stability of the media. The filter media achieves acceptable alpha values for a range of filtration challenges without significant decay in alpha values over time. Preferred charge additives include fatty acid amides, oleophobic fluorochemical surfactants, and mixtures thereof.

Abstract: The filter system comprises a filter element (10) arranged in wave- or zig-zag-shaped folds and having flat filter element portions (12) and intermediate bending lines (14). The longitudinal edges of the filter element (10) are connected to tensioning bands (20). When the filter element (10) is stretched, these tensioning bands (20) are tensioned and in their tensioned condition fulfill a holding function for holding the filter element portions (12) in the stretched condition of the filter element (10). Thus, no spacers are required on the filter frame (22) for maintaining the stability of shape of the filter element (10).

Abstract: A nonwoven disposable face mask includes a filtration layer formed of a plurality of thermoplastic microfine meltblown microfibers having an average fiber diameter of less than 1.5 microns. The filtration layer also has a basis weight of less than ten grams per square meter. The resultant face mask provides improved wearer comfort and barrier and filtration properties.

Abstract: Electrets are disclosed comprising syndiotactic vinyl aromatic polymer, for example syndiotactic polystyrene. These electrets have good charge retention at elevated temperature.

Abstract: A personal dust sampler hangs from a ribbon (10) attached to the user's clothing and requires no pump or power source. Dust in the air is captured by a charged PVC sheet (2) exposed at (2a) but framed by a metal foil (25) and surmounted by a metal conductor plate (6) parallel to the charged PVC sheet (2). The plate (6) is supported by conductive gridwork (3) removably attached by a flange (3) to a metal base (21). The dust captured is determined in a method by weighing or by measuring the charge loss of the PVC sheet (2).

Abstract: A method for post-treating a laminated precursor nonwoven web which includes layers of thermoplastic man-made fibers and at least one layer of cellulose-based staple natural fibers, including consolidating the web laterally and thereby reducing the maximum pore size measure of the web. The precursor web and the resultant consolidated nonwoven web are also disclosed, as is utilization of the product web in medical uses.

Abstract: The present invention provides a filter medium, which contains an electretized nonwoven web of crimped fibers selected from the group consisting of spunbond filaments and staple fibers, wherein the nonwoven web has a Frazier permeability equal to or greater than about 100 ft.sup.3 /min/ft.sup.2 and a density between about 0.01 g/cm.sup.3 and about 0.095 g/cm.sup.3.

Abstract: A vacuum cleaner having a reduced velocity chamber with a high velocity air inlet, an electric motor, a rotary mechanism driven by the motor for creating a vacuum in the chamber, an outlet for exhausting air from the chamber, which air flows in a selected path from the air inlet, through the chamber and out the air exhaust outlet and a disposable porous sheet filter layer in the chamber for removing solids particles from the air. The vacuum cleaner also has a fiber filter between the filter layer and the motor where the fiber filter has an electrically charged non-woven material for removing very fine air particles in the chamber, intersecting the air path and generally coterminous with the disposable filter layer.

Abstract: A corona-assisted electrostatic filtration apparatus which includes a cathode, an anode filter element, and a means of establishing a nonalternating potential difference between the cathode and the anode which is sufficient to maintain a corona field of ionized gas between the cathode and the anode filter element. The anode filter element includes a porous fibrous sheet material having pores in a range of from about 0.1 to about 100 micrometers, with at least a portion of the fibers thereof being uniformly coated with a metal. Also provided is a method of utilizing such apparatus to remove particulate matter from a gaseous medium.

Abstract: An air treatment system includes a housing having a from cylindrical chamber and a rear rectangular chamber, the front and rear chambers being separated by an internal wall. The front chamber is provided with a series of outlet vents, the rear chamber is provided with a series of inlet vents, and the internal wall is provided with a series of interchamber vents. A pair of electrically-powered cylindrical fan blades are disposed within the front chamber and are used to draw air into the rear chamber through the inlet vents, to move the air from the rear chamber to the front chamber through the interchamber vents and to exhaust the air from the front chamber through the outlet vents. A plurality of ionizer needles are also disposed within the front chamber. The rear chamber is shaped to include a generally rectangular reservoir. The air treatment system also includes a water tank removably mounted within the rear chamber for use in supplying water to the reservoir.

Abstract: A filter apparatus for a reusable one piece filter frame housing and a filter media for use in a forced air ventilating system. The one piece filter frame housing having integrally formed fasteners to releasably secure a replaceable filter media. The filter frame housing further having an "I" beam structure to enhance filter frame strength. The filter frame housing also having an electrostatic charge.

Abstract: To manufacture a thin sheet electret of small size having charge distributed in very uniform manner, even at its edges, use is made of a device comprising a grounded electrode (2) for supporting a dielectric (1) to be charged, means for generating ions (3) in the vicinity of the dielectric, a grid (4) extending parallel to the surface to be charged of the dielectric, at a small distance from said face, and raised to an electric potential different from ground potential and a conductive frame (7) that is insulated from the electrode and that is electrically connected to the grid, said frame surrounding the dielectric and forming a single block with the electrode.

Abstract: An electrostatic filter of a combination of a layer of filter material having electrostatic properties and a layer of filter medium without electrostatic properties. The medium is a lofted material arranged to retain particles in the sub-micron and lower micron ranges, and in use, is located upstream of the material. The invention also includes a method of filtering dust from the atmosphere utilizing the electrostatic filter.

Abstract: An air cleaner incorporating a plurality of filtration techniques within a rigid, gasketed frame designed to fit in conventional filter tracks. A perimeter gasket attached to the frame leaving air side provides a positive seal thereby preventing air from bypassing the frame. The frame houses, in series from the entering air side, a replaceable dry-type media filter coated on its leaving air side with a viscous substance, and a synthetic weave having a charge separation producing local electrostatic effects. The replaceable media effectively comprises two stages of filtration; dry-type media filtration, and viscous impingement filtration. Air passing through the instant filtration configuration is efficiently cleaned with little resistance.

Abstract: A method of charging a nonwoven web of thermoplastic microfibers to provide electret filter media is provided. The method includes impinging on a nonwoven web of thermoplastic nonconductive microfibers capable of having a high quantity of trapped charge jets of water or a stream of water droplets at a pressure sufficient to provide the web with filtration enhancing electret charge and drying said web.

Abstract: The present invention is an air filter assembly which includes a frame having a filter mounted therein. The filter is constructed of woven microfilament strands having a cross-sectional height of at most 30 microns, the strands being spaced apart by at most 20 microns. The filter medium is single-ply so as to be non-entraining. Each strand preferably has a smooth outer surface for repelling particles smaller than the size of the openings in the filter. The frame may laterally adjustable, if desired. In an alternative embodiment, the filter includes a single-ply sheet of a filtering material having openings cut therein. The filtering material preferably has a smooth outer surface facing the air-flow for preventing the particles from clogging the filter. The openings may be made in the filtering material by processes such as laser cutting, x-ray lithography, chemical etching, or by stretching a microporous sheet.

Abstract: An oily mist resistant electret filter media is provided. The filter media includes polypropylene electret fibers and a melt processable fluorochemical additive, the additive having a melting point of at least 25.degree. C. and a molecular weight of about 500 to 2500.

Abstract: A method for post-treating a precursor nonwoven web including consolidating the web laterally and thereby reducing the maximum pore size measure of the web. The resultant nonwoven web is also disclosed as is utilization of the product web as a filter.