[001] This application claims priority under 35 USC § 119 to U.S. Provisional Application No. 63/142,597, filed January 28, 2021, which is incorporated herein by reference in its entirety.

[002] The present invention relates to personal protective equipment such as face masks. The masks can include a manually attachable filter and can be sterilized or disinfected to allow reusability. The masks can be sized and shaped to conform to a wearer’s face.

[003] Various types of face masks are used in health care or other setting to prevent the transmission of airborne pathogens. However, some face masks either protect the wearer or protect others from airborne pathogens but are not effective for both. In addition, face masks are often not easily sterilizable to allow cost-effective reuse.

[004] There therefore exists a need in the art for a face mask or respirator that can address at least some of the shortcomings of known face masks or respirators. Accordingly, the present disclosure provides face masks that can be sterilized or cleaned easily for reuse and can accommodate a number of different types of filters. Furthermore, the presently described masks have improved or customizable shapes to improve comfort, especially during longterm use, and the masks include structures that allow simple replacement of filter components without extensive training or equipment.

SUMMARY

[005] In some exemplary embodiments, a face mask for filtering inhaled and exhaled gases is provided. The mask includes a body configured to fit the contour of a human face and a manually attachable and detachable housing for a filter. The mask can be formed of a sterilizable material.

[006] In one exemplary embodiment, a face mask includes a flexible body shaped to follow a contour of a human face and conform to a cheek structure of the face, the body including an opening; a receiving element disposed adjacent to the opening including a protrusion; a cap configured to retain a filter and including a channel; and a plug including a rib shaped to fit within the channel and including an aperture configured to receive the protrusion. [007] In some embodiments, the mask further includes a group of straps configured to secure the mask to the human face. The group of straps may be positioned in an earloop configuration, a cross configuration, and/or include a hook and loop fastener.

[008] In some embodiments, the cap and the receiving element are configured to be manually attached or detached to or from the plug. In some embodiments, the body further includes a flange. In further embodiments, the mask further includes a clip situated on the flange and configured to conform the flange of the mask to a nasal structure of the face.

[009] In some embodiments, the body is composed of material that is stable at temperatures of at least 150 degrees Fahrenheit. In some embodiments, the cap and the plug form a first seal around the filter. In further embodiments, the receiving element and the plug form a second seal around the filter. In further embodiments, the plug includes a plurality of holes disposed within a middle portion of the plug. In some embodiments, the mask includes a filter.

[0010] In one exemplary embodiment, a method of assembling a mask includes selecting a body shaped to generally follow a contour of a human face and conform to a cheek structure of the face, the body including an opening; positioning a filter within a cap including a channel; compressing the of a plug into the channel, creating a first seal around the filter; positioning the attached cap and plug adjacent to the opening; positioning adjacent to an opposite side of the opening a receiving element including a protrusion; and inserting the protrusion into the aperture of the cap, creating a second seal around the filter.

[0011] In some embodiments, the cap is manually attachable and detachable to or from the plug, and the plug is manually attachable and detachable to or from the receiving element. In some embodiments, the method further includes adjusting a clip on the body to conform the body to a nasal structure of the face.

[0012] In some embodiments, the method further includes detaching the receiving element from the plug; detaching the plug from the cap; removing the filter; and positioning a second filter within the cap. In further embodiments, the method includes, after positioning a second filter within the cap, compressing the rib of the plug into the channel, creating a first seal around the second filter; positioning the attached cap and plug adjacent to the opening; positioning adjacent to the opposite side of the opening the receiving element; and inserting the protrusion into the aperture of the cap, creating a second seal around the second filter. In further embodiments, the method further includes sterilizing the body, the receiving element, and the cap prior to positioning the second filter. In further embodiments, the sterilizing is performed in an autoclave or dishwasher. In further embodiments, the body is comprised of material that retains its structure at temperatures of at least 150 degrees Fahrenheit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Fig. 1 is a perspective view of an exemplary embodiment of a face mask on a face;

[0014] Fig. 2 is a bottom view of the mask shown in Fig. 1 worn on a face;

[0015] Fig. 3 is a perspective view of the face mask shown in Fig. 1 without associated straps;

[0016] Fig. 4 is a front view of the mask shown in Fig. 1;

[0017] Fig. 5 is a rear/facial side view of the mask shown in Fig. 1 ;

[0018] Fig. 6 is a right side view of the mask shown in Fig. 1;

[0019] Fig. 7 is a left side view of the mask shown in Fig. 1

[0020] Fig. 8 is a top view of the mask shown in Fig. 1 ;

[0021] Fig. 9 is a bottom view of the mask shown in Fig. 1;

[0022] Fig. 10 is a perspective view of a face mask without a filter assembly attached;

[0023] Fig. 11 is an exploded view of the mask shown in Fig. 1;

[0024] Fig. 12 depicts a conventional filter shape as may be used with the presently disclosed mask;

[0025] Fig. 13 is a cut-away view of the mask shown in Fig. 1;

[0026] Figs. 14A-E depict manual assembly of a filter assembly.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0027] Reference will now be made in detail to certain exemplary embodiments according to the present disclosure, certain examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0028] In this application, the use of the singular includes the plural unless specifically stated otherwise. In this application, the use of “or” means “and/or” unless stated otherwise. Furthermore, the use of the term “including,” as well as other forms such as “included” and “includes,” is not limiting. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application including but not limited to patents, patent applications, articles, books, and treatises are hereby expressly incorporated by reference in their entirety for any purpose.

[0029] Referring now to the drawings, Figs. 1 and 2 illustrate an exemplary embodiment of a mask 100 as worn by a user. The mask 100 may be secured snugly to the user’s face providing a seal around a periphery 122. The sealed periphery 122 will prevent air flow in and out of the mask 100 except through filters 140, which are described in more detail below.

[0030] As shown, the mask 100 includes a body 110 formed of relatively flexible material. The flexibility of the body 110 allows for the mask 100 to be manually manipulated to snugly secure to the user’s face and create the sealed periphery 122, as discussed in more detail below.

[0031] The body includes one or more filter assemblies 135 (labeled in Fig. 11). As discussed in more detail below, the filter assembly includes filters 140, which can be manually detached, eg., to allow cleaning or sterilization of the body 110 and replacement of the filters 140. A user may disassemble the filter assemblies 135 to replace the filters 140 within the filter assemblies 135. The filters 140 may be replaced without discarding other components of the mask, which may be sterilized and reused. The exploded view of Fig. 11 makes receiving element 130 appear to be situated on a side of the body 110 that is outside of a wearer’s face. However, depicted in Fig. 5, the receiving element 130 may be disposed on the side of the mask 100 that contacts a face.

[0032] The mask 100 can include securing means for holding the mask 100 on a user. For example, one or more straps 170 may be used to secure the mask 100 to the face. As shown in Figs. 1 and 2, the mask may include two or more straps. The configuration of the straps 170 is discussed in further detail below. [0033] The body 110 can be formed from a variety of materials and have a number of different shapes. In some embodiments, the body 110 is formed from polymeric or thermoplastic materials. In some embodiments, the body 110 is formed from silicone rubber. The silicone rubber may be opaque, translucent, or transparent.

[0034] The body 110 can be formed from materials that provide sufficient flexibility to conform the body 110 to the contours of a user’s face. For example, the body 110 should be able to be manipulated by a user to conform the body 110 to the cheek structure of the user such that the periphery 122 of the mask 100 creates a seal on the user’s face. In such embodiments, the body 110 is formed from materials that also possess sufficient rigidity to retain its shape once secured on the user’s face.

[0035] The body 110 can be formed from materials that can withstand sterilization and/or disinfection. Such materials may be stable at temperatures employed for sterilization and disinfection, for example at least 150 degrees Fahrenheit. For example, the body 110 can be sterilized or disinfected in devices such as an autoclave or dishwasher. Alternatively, the body 110 can be formed from materials that are amenable to cleaning with sterilizing agents such as conventional medical-grade cleaning agents.

[0036] In some embodiments, the body 110 can be formed from material that is non- allergenic. In such embodiments, the body 110 can be formed from polymeric or thermoplastic materials that do not incur allergic reactions on a user’s skin. For example, the body 110 may not be composed of latex materials, a common allergen.

[0037] In some cases, the shape and material of the body 110 conform to parts of a user’s face. In some embodiments, the curvature of the body 110 may correspond to the general curvature of a human face. The body 110 may be sufficiently flexible to adjust the curvature of the periphery 122 to the curvature of a specific user’s face, as described above. In some embodiments, the body 110 may be adjusted by manipulating the straps 170, as discussed in further detail below.

[0038] The body 110 and/or periphery 122 may conform to the cheek structure of the face. In some embodiments, the upper portion of the periphery 122 of the mask 100 follows the contour of each cheek, forming an airtight seal. For example, the portion of the periphery 122 leading from the uppermost point of the body 110 to a middle point of the body 110 may be curved. [0039] As shown in Figures 3-5, the body 110 may include one or more protruding surfaces 115 that assist in stabilizing the mask 100 against a face. Such protruding surfaces 115 may extend out from the body 110, forming additional surface area of the mask 100 to rest against the cheek(s) of a user. In some embodiments, each protruding surface 115 is situated on an upper part of the body 110. In some embodiments, the protruding surfaces 115 are curved. In other embodiments, the protruding surfaces 115 have straight edges that form a corner.

[0040] In some embodiments, the protruding surfaces 115 serve as a base for the attachment of one or more straps 170. In some embodiments, the one or more straps 170 pass through the protruding surfaces 115. In other embodiments, the one or more straps 170 are attached to an outer surface of the protruding surfaces 115. The straps 170 are discussed in further detail below.

[0041] The body 110 and/or periphery 122 may also conform to the chin structure of a user’s face. In some embodiments, the lower portion of the periphery 122 follows the contour of a user’s chin. For example, the periphery 122 may rest below a user’s jawline, forming part of an airtight seal around the chin. The body 110 may be sufficiently flexible to adjust the shape of the periphery 122 to the shape of a specific user’s jawline, as described above.

[0042] In some embodiments, the mask 100 may be commercially available in one or more sizes. The sizes may generally correspond to facial sizes and/or body types of a user. For example, one size may correspond to skinny, gaunt, or emaciated faces. One size may correspond to faces possessing a higher fat content. Another size may correspond to faces of people of “average” size. Masks may also be sized for children, teenagers, and/or adults. In some embodiments, masks may be offered in sizes of “small,” “medium,” or “large.”

[0043] In other embodiments, a user can provide facial measurements to a retailer or manufacturer. The body 110 of the mask 100 may then be manufactured at a size and shape to conform to the provided facial measurements. In some embodiments, the body 110 and periphery 122 are customized according to the provided measurements but other elements of the mask 100, such as the filter assembly 135, are not customized. Elements of the filter assembly 135 may be sized and shaped to correspond to the filters 140 employed with the mask 100.

[0044] A customized mask 100 may include a periphery 122 with a specific curvature to match a user’s cheek structure. Additionally, or alternatively, a customized mask may include a periphery 122 shaped to conform to a user’s specific jawline. Customized masks 100 may create an airtight seal on a user’s face without the need for a user to manually manipulate the shape or curvature of the mask 100. In some embodiments, a customized mask 100 may be made from a relatively inflexible material.

[0045] Figs. 3-9 provide various views of an embodiment of mask 100 when not located on a face. As noted above the body 110 includes a filter assembly 135. The filter assembly 135 can allow for rapid, manual removal and replacement of filters 140. Further, removal of the filter 140 can permit sterilization of the remaining elements of the mask 100 for reuse.

[0046] The unassembled components of the filter assembly 135 can be viewed in Figure 11. In general, the filter assembly 135 includes a receiving element 130, a filter 140, a cap 150, and a plug 160. Each element of the filter assembly 135 is discussed in further detail below. The filter assembly 135 is generally airtight around the periphery such that air only flows in and out by passing through filters 140 to remove airborne pathogens and particles from air entering and leaving the mask 100. Each component of the filter assembly 135 is discussed in further detail below.

[0047] Each filter assembly 135 is situated around an opening 120 in the body 110. In some embodiments, the body 110 includes two filter assemblies 135 and two openings 120. The openings 120 may be situated on opposing sides of the center axis of the body 110. The opening 120 may be circular in shape or may be any suitable shape for allowing the passage of air and appropriate disassembly and replacement of filter 140.

[0048] In some embodiments, body 110 and the material surrounding the opening 120 are composed of the same material. In other embodiments, body 110 and the material surrounding the opening 120 are composed of different materials. In some embodiments, the body 110 and the material surrounding the opening 120 are composed of materials that can withstand sterilization and/or disinfection. In further embodiments, the body 110 and the material surrounding the opening 120 are composed of silicone rubber. The body 110 and the material surrounding the opening 120 are composed of materials that retain their structure at temperatures employed for sterilization and disinfection, for example at least 150 degrees Fahrenheit. Such materials can be sterilized or disinfected in devices such as an autoclave or dishwasher. In some embodiments, the selected material is non-allergenic as described above. [0049] The filter assembly 135 includes a receiving element 130. The receiving element 130 is disposed adjacent to the opening 120. In some embodiments, one receiving element 130 is disposed adjacent to each opening 120. The receiving element 130 includes at least one first protrusion 132. As depicted in Fig. 5, the receiving element 130 may be disposed on the side of the mask 100 that contacts a face.

[0050] In some embodiments, the receiving element 130 is composed of a material that can withstand sterilization and/or disinfection. In further embodiments, the receiving element 130 is composed of polymeric or thermoplastic material. By way of non-limiting example, the receiving element 130 may be composed of polypropylene, polyethylene, polyetheretherketone and polyphenylsulfone. The receiving element 130 may be composed of a material that retains its structure at temperatures employed for sterilization and disinfection, for example at least 150 degrees Fahrenheit. Such materials can be sterilized or disinfected in devices such as an autoclave or dishwasher. In some embodiments, the selected material is non-allergenic as described above.

[0051] In other embodiments, the receiving element 130 may not be intended for sterilization and/or disinfection. In such embodiments, the receiving element 130 may be discarded prior to sterilization and/or disinfection of the body 110. A new receiving element 130 may be employed in a new filter assembly 135 after sterilization and/or disinfection.

[0052] The filter assembly 135 further includes at least one cap 150 detachably connected to a plug 160. The cap 150 is configured to create an airtight seal with the plug 160 around a filter 140. In some embodiments, there is one cap 150 and plug 160 for each receiving element 130. The cap 150 and plug 160 are positioned on a side of the body 110 opposite of the receiving element 130.

[0053] The filter may be situated against the center of the cap 150 and the plug 160. The filter 140 may be situated that any gases exhaled out of opening 120 and through the filter assembly 135 must pass through the filter 140. In some embodiments, a secondary exhalation valve may be present on the body 110. The secondary valve may release exhaled gases that do not immediately pass through the filter 140. For example, a wearer of the mask 100 with a larger volume of inhalation and exhalation may require additional surface area for the release of exhaled gases. In some cases, the exhalation valve may be equipped with a filter to remove particulate material. [0054] Filter 140 may be a conventional commercially available filter, such as the filter as depicted in Fig. 12. Examples of conventional filters include N95, N99, N100, R95, P95, P99, or P100 material. Filters 140 also may be furnace filters, coffee filters, vacuum bag filters, surgical wrap material, or cotton material, for example.

[0055] A user may select the material of filter 140 in accordance with the desired use of the mask 100. For example, if a user is intending to filter out dust particles during home improvement projects, the user may select a lower grade filter. As another example, if a user is visiting a sick person or a hospital, the user may select a higher grade filter to filter out airborne pathogens. The detachable filter assembly 135 allows for filters 140 to be switched out by the user for different purposes without replacing the body 110 of the mask 100.

[0056] The filter 140 is depicted as circular in shape but one of skill in the art would appreciate that the mask 100 may be reconfigured to accommodate filters 140 of various shapes and sizes. Alternatively, the filter 140 may be shaped to conform to the shape of the cap 150. For example, a conventional filter 140 may be cut to a desired shape. A user may purchase a sheet of filter material and cut a desired filter 140 from the sheet.

[0057] The filter 140 removes airborne pathogens and particles from air that is breathed in or out by the user. Specifically, the airtight seal of the periphery forces air from the nose or mouth of a user, or from outside the mask 100, through the opening 120. Therefore the air is forced through the airtight seal(s) created by the filter assembly 135 through the filter 140, which is situated within the assembled cap 150 and plug 160 adjacent to the opening 120. Filtration of air both entering and exiting the mask 100 is a feature that is not provided by conventional face masks.

[0058] In some embodiments, the cap 150 is composed of a material that can withstand sterilization and/or disinfection. In further embodiments, the cap 150 is composed of polymeric or thermoplastic material. By way of non-limiting example, the cap 150 may be composed of polypropylene, polyethylene, polyetheretherketone and polyphenylsulfone. The cap 150 may be composed of a material that retains its structure at temperatures employed for sterilization and disinfection, for example at least 150 degrees Fahrenheit. Such materials can be sterilized or disinfected in devices such as an autoclave or dishwasher. In some embodiments, the selected material is non-allergenic as described above. [0059] In other embodiments, the cap 150 may be composed of a material that cannot withstand sterilization and/or disinfection. In such embodiments, the cap 150 may be discarded prior to sterilization and/or disinfection of the body 110. A new cap 150 may be employed in a new filter assembly 135 after sterilization and/or disinfection.

[0060] The cap 150 includes at least one channel 154 configured to receive a rib 162 of the plug 160. In some embodiments, the rib 162 compressibly fits within the channel 154. For example, a user may press together the cap 150 and plug 160 to move the rib 162 within the channel 154. When pressed together, the rib 162 and channel 154 may produce a “click” sound to indicate that the rib 162 and channel 154 are snuggly and securely compressed. In some embodiments, there is one channel 154 for each rib 162. In other embodiments, the cap 150 may be twisted to lock the rib 162 within the channel 154.

[0061] In some embodiments, the plug 160 is composed of a material that can withstand sterilization and/or disinfection. In further embodiments, the plug 160 is composed of polymeric or thermoplastic material. By way of non-limiting example, the plug 160 may be composed of polypropylene, polyethylene, polyetheretherketone and polyphenylsulfone. The plug 160 may be composed of a material that retains its structure at temperatures employed for sterilization and disinfection, for example at least 150 degrees Fahrenheit. Such materials can be sterilized or disinfected in devices such as an autoclave or dishwasher. In some embodiments, the selected material is non-allergenic.

[0062] In other embodiments, the plug 160 may be composed of a material that cannot withstand sterilization and/or disinfection. In such embodiments, the plug 160 may be discarded prior to sterilization and/or disinfection of the body 110. A new plug 160 may be employed in a new filter assembly 135 after sterilization and/or disinfection.

[0063] The plug 160 may include a rib 162 configured to fit within the channel 154 of the cap 150. The assembled cap 150 and plug 160 form a first seal around the filter 140. The first seal is defined as a configuration in which gases cannot pass around the outer edges of the filter 140. For example, the outer edges of a filter 140 are situated between assembled plug 160 and cap 150. The first seal is configured to force any gases moving through opening 120 through the filter 140.

[0064] The rib 162 may be in the form of a circular ring. In some embodiments, the rib 162 is situated around the center of the plug 160. In some embodiments, the rib 162 is a female U- shape feature. In further embodiments, channel 154 is a male U-shaped feature. The rib 162 and channel 154 may be separated by manually pulling apart the cap 150 and plug 160.

[0065] The plug 160 may further include a plurality of holes 166 situated in the center portion of the plug 160 to permit the passage of gases. The holes 166 are aligned with the filter 140. The plug 160 and holes 166 are configured to route gases through the filter 160 instead of around the filter 140.

[0066] The receiving element 130 may include one or more protrusions 132. In some embodiments, the protrusions 132 are tabs. All or portions of the tab 132 may in the shape of a cylinder, cone, cuboid, prims, pyramid or other shape capable of securing the receiving element 130 to the plug 160. For example, each tab 132 may include a cuboid base and a tapered distal end. In some embodiments, the a portion of the distal end of the tab 132 is wider that the cuboid base.

[0067] Each tab 132 may be insertable into an aperture 164 of the plug 160. In some embodiments, the tab 132 may be pushed into the aperture 164. In some embodiments, the tab 132 locks into place after passing through the aperture 164. For example, each tab 132 may be situated at a sufficient angle such that the tab 132 cannot exit the aperture 164 after entry into the aperture 164. In such embodiments, the tabs 132 may be squeezed towards the center of the receiving element 130 to insert or remove the tabs 132 into or from the apertures 164.

[0068] The receiving element 130 may be disposed on the side of the mask 100 that contacts a face. In some embodiments, when the tab 132 is pushed into the aperture 164, the tabs 132 extend through an opening 120, joining the receiving element 130 disposed on the “face side” of the mask 100 to the plug 160 on the “outer side” of the mask 100. The connection of the receiving element 130 and the plug 160 (along with filter 140 and cap 150) secures the filter assembly 135 to the body 110.

[0069] The receiving element 130 and the connected cap 150 and plug 160 form a second airtight seal around the filter 140. In some embodiments, a seal is defined as a configuration in which gases cannot pass around the outer edges of the filter 140.

[0070] In some embodiments, the second airtight seal may include an overmolded compression ring situated between the plug 160 and the cap 150. The overmolded compression ring may be configured to accommodate a filter 140 of greater thickness than conventional N95 material filters.

[0071] As depicted in Figs. 1 and 2, the mask 100 further includes at least one strap 170 configured to secure the mask 100 to a human face or head. Each strap 170 is detachably connectable to the body 110 of the mask 100. For example, each strap 170 may pass through an opening 175 in the body 110. In some embodiments, one strap 170 passes through each opening 175.

[0072] The strap(s) 170 may be tightened or loosened manually to adjust to the size of a wearer’s head. For example, the strap 170 may include an adjuster to change the length of the strap 170. Additionally or alternatively, an end of each strap 170 may be pulled through an opening 175 to lengthen or shorten the portion of the strap 170 contacting a user’s head or neck. Adjusting the length of the strap 170 conforms and deforms the body 110 to and from the user’s face.

[0073] In some embodiments, the strap 170 is attached to an opening 175 situated on an upper corner of the body 110, in other words a corner of the body 110 that is situated near a cheek structure of a face. In some embodiments, the strap 170 is attached to an opening 175 situated on a lower corner of the body 110, in other words a comer of the body 110 that is situated near the chin of a face. In embodiments including multiple straps 170, straps may be situated in both upper and lower comers of the body 110.

[0074] In some embodiments, the straps 170 may be configured in an earloop configuration. An earloop configuration includes two straps 170, one strap 170 lying over each ear of a user. In an earloop configuration, each strap 170 passes through one or more openings 175 on a side of the mask 100 corresponding to the ear the strap 170 is situated around. For example, a strap 170 situated over the left ear may pass through an opening 175 in the upper left comer and the lower left corner of the body 110.

[0075] In some embodiments, the straps 170 may be configured in a crossed configuration. In a crossed configuration, one strap 170 is situated around the top of a user’s head and another strap 170 is situated around the back of a user’s neck. The strap 170 situated over the head may pass through an opening 175 in the upper left comer and the upper right corner of the body 110. The strap 175 situated around the back of the neck may pass through an opening 175 in the lower right corner and the lower left comer of the body 110. [0076] In some embodiments, the straps 170 may include a hook and loop fastener, for example VELCRO®. Straps 170 that include a hook and loop fastener may be thicker than straps 170 in embodiments without hook and loop fasteners.

[0077] The strap 170 may be composed of fabric, polymeric material, or cotton material. In some embodiments, the strap 170 may be elastic. The strap 170 may be composed of a material that retains its structure at temperatures employed for sterilization and disinfection, for example at least 150 degrees Fahrenheit. Such materials can be sterilized or disinfected in devices such as an autoclave or dishwasher. In some embodiments, the selected material is non-allergenic as described above.

[0078] In other embodiments, the strap 170 may be composed of a material that cannot withstand sterilization and/or disinfection. In such embodiments, the strap 170 may be discarded prior to sterilization and/or disinfection of the body 110. A new strap 170 may be employed after sterilization and/or disinfection.

[0079] In some embodiments, the body 110 further includes a flange. The flange may be situated on the portion of the body 110 that will be situated on a nasal structure of a wearer. In further embodiments, the body 110 further includes a clip 180 situated on the flange. The clip 180 is configured to conform the flange of the body 110 to the nasal structure of the wearer. In some embodiments, clip 180 is metallic. In further embodiments, the clip 180 is composed of aluminum. In some embodiments, the body 110 includes a flange but does not include a clip 180. In some embodiments, the flange extends around the nasal structure and mouth of the wearer. In further embodiments, the flange extends 360 degrees around the nasal structure and mouth of the wearer.

[0080] The filter assembly 135 of the disclosed mask may be manually assembled and disassembled by a wearer. For example, a method of assembling a mask may include selecting a body shaped to generally follow a contour of a human face and conform to a cheek structure of the face. Then a filter may be positioned within a cap comprising a channel. For example, the filter may be positioned in the center area of the cap surrounded by the channel. A plug may then be attached to the cap, creating a first seal around the filter.

[0081] Figs. 14A-14E depict manual assembly of filter assembly. Fig. 14A depicts a front view of a filter 140 aligned within a cap 150. Fig. 14B depicts a back view of the filter aligned within the cap 150. 140 The filter 140 is placed in the middle of the cap 150 such that the filter completely covers the hole in the cap 150. In some embodiments, the filter 140 should be visible through the channels 154 of the cap 150.

[0082] Fig. 14C depicts manual alignment of plug 160 with the assembled filter 140 and cap 150. In some embodiments, the plug 160 includes a rib shaped to fit within a channel 154 of the cap 150. A user may align the rib over the channel 154 before joining the cap 150 and plug 160. A user may then press the plug 160 into the cap 150 to compress the rib within the channel 154.

[0083] Alternatively, as depicted in Figs. 14D and 14E, the user may twist the cap 150 join the rib and channel 154, creating the first seal. In some embodiments, the cap 150 may be twisted counter-clockwise. In some embodiments, the cap 150 includes multiple channels 154 and the plug 160 includes a corresponding number of ribs. In some embodiments, upon creation of the first seal a “click” sound is produced by the joining of the channel 154 and the rib to audibly indicate that the creation of the seal.

[0084] The attached cap and plug may be positioned next to an opening in the mask body. Then a receiving element may be positioned adjacent to the opposite side of the opening. Then, the receiving element may be attached to the plug, creating a second seal around the filter and securing the entire filter assembly to the body of the mask. For example, a user may squeeze tabs situated on the receiving element to pass the tabs through apertures on the plug and secure the receiving element to the plug.

[0085] The mask may be dissembled in a similar manner. For example, a user may squeeze the tabs to remove the receiving elements from the plug. Then the user can manually separate the rib from the channel to separate the plug and cap. Once separated, the filter may be removed from within the cap and discarded. A new filter may then be positioned within the cap. Then the cap, plug, and receiving element may be reattached as described above, creating a first seal around the new filter.

[0086] After the assembly of the filter assembly, a user may manipulate the body of the mask to conform to the user’s face. Manipulation of the mask may include adjusting a clip situated on a flange of the mask body to conform the flange to the user’s nasal structure. The user may also manipulate the upper portion of the mask to conform to the user’s cheek structure. The user may also manipulate the lower portion of the mask to conform to the user’s jawline. The user may also adjust one or more straps connected to the body around the head of the user to create an airtight seal on the user’s face.

[0087] Either before assembly or after removal of the filter following disassembly, the mask may be sterilized. For example, the mask body, the receiving element, the cap, the clip, the strap, and/or the plug may be sterilized or disinfected in an autoclave or dishwasher. After sterilization and/or disinfection, the components of the mask may be assembled as described above. In some embodiments, the straps and/or clip are removed from the mask prior to sterilization and/or disinfection. The straps and/or clip may be discarded and replaced or reattached to the mask after sterilization and/or disinfection.

[0088] Masks including three part filter assemblies as described above were tested against masks including one or two part filters. The three part filter assembly generally provided for greater removal of airborne particles and pathogens.

[0089] While the present invention has been described herein in conjunction with certain exemplary embodiments, a person of ordinary skill in the art can effect changes, substitutions or equivalents to the systems and methods described herein, which are intended to fall within the appended claims and any equivalents thereof.