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.

Filter media are described. In particular, a filter media includes an intake side, an exhaust side, and a plurality of fibers distributed throughout the filter media. The fibers have a plurality of deniers, and fibers disposed proximate the intake side have a first denier and fibers disposed proximate the exhaust side have a second denier. The first denier is larger than the second denier.

A filter media construct includes a plurality of flexible laminas joined in a stack, each lamina including an array of nanofibers extending from a surface thereof. Each lamina is configured to be permeable to a fluid such that the fluid can flow through each lamina normal to the surface thereof and in any direction along at least a portion of said surface when the fluid is flowed through the construct. The laminas can include a plurality of perforations extending therethrough such that the fluid flows through at least some of the perforations of the laminas when the fluid is flowed through the construct. A contaminant contained in the fluid is at least partially filtered from the fluid by the nanofibers when the fluid is flowed along the surface of any lamina or into or through the perforations.

Embodiments disclosed herein include a stitched filtering fabric including a barrier layer configured to inhibit air flow through the filtering fabric, a yarn stitched through and forming a plurality of stitch holes in the barrier layer, and a first yarn layer comprising interlocking loops of the yarn. The barrier layer is configured to direct air flow through the yarn within the stitched holes.

An air filter for automobiles includes, a main filter and a prefilter, wherein the prefilter comprises a nonwoven synthetic fiber having an average density of 0.01 to 0.5 g/cm.sup.3 and a moisture absorbent is adsorbed to the prefilter.

A filtration material of the present invention comprises a bulky fiber sheet layer having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer in which two or more types of fibers different in constituent resin are mixed, wherein constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layer. A three-layer filtration material of the present invention comprises bulky fiber sheet layers having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer, which is located between the bulky fiber sheet layers, wherein the constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layers, and both bulky fiber sheet layers contain fibers having a limiting oxygen index of 20 or more, and have a mass per unit area 0.5 times or more than that of the triboelectrically-charged nonwoven fabric layer. A filter element of the present invention comprises the filtration material in a pleated state.

Disclosed herein are washable, reusable, antimicrobial and antiviral face masks and methods of their use for the reduction of transmission of infectious pathogens. Exemplary face masks are made of silver-coated material wherein activation of the silver from moisture in a user's breath kills pathogens. The disclosed face masks are useful in reducing, inhibiting or killing pathogens, such as SARS-CoV-2, that contact the face mask within 2 hours of continuous contact.

The present invention relates to a mask comprising a mask body for covering a wearer's face and wearing straps coupled to both sides of the mask body, the mask body comprising a filter member having: a support layer having a mesh structure; and a filter coating layer formed on the outer surface of the support layer and for filtering contaminants, wherein the filter coating layer is formed from a microfiber web eletrospinned on the support layer.

A head garment is made of elastically stretchable fabric configured to fit over and surround the head of a wearer and conform substantially to the shape of the wearer's head. The head garment has an eye opening positioned to allow the wearer to see therethrough, and a protective eye shield completely covering the eye opening. A multi-layer filter portion is configured to cover the wearer's mouth and at least a lower part of the wearer's nose and has three or more filter layers for filtering air during breathing. Additional filter layers may be added to the multi-layer filter portion to enhance or modify the filtering properties. The multi-layer filter portion may be configured as a removable filter pack that can be removed and replaced by other filter packs having different filtering properties.

A device and method for manufacturing a specially designed face mask that allows the free and vigorous inhalation of air for singing and speaking is disclosed. A minimalization of the broadcast of aerosolization particles as exhaled air is directed downward toward a variety of filter materials. The mask has at least one layer of material and at least one method of holding the mask in place in front of the nose and mouth of the wearer. The mask is designed to function such that the material is suspended away from the openings of the mouth and nose, including being held in place in front of the nose and mouth openings by one of any number of methods, such as elastic straps around the head, elastic loops around the ears, or other means.