Respiratory protection device and method for manufacturing the same

Abstract

A respirator comprising a layer of wrinkled medium is described. The wrinkled medium comprises a first series of substantially parallel and unbonded elastic filaments between a first nonwoven porous web and a second nonwoven porous web. The first nonwoven porous web is directly bonded to the second nonwoven porous web. At least a portion of the wrinkled medium is elastically stretchable under tension.

Description

Technical Field

[0001] A respiratory device comprising a wrinkled expandable filter medium that enables elasticity (stretchability) and low pressure loss, reducing respiratory resistance and providing improved comfort and fit to the wearer. A respiratory device comprising a wrinkled expandable filter medium that enables elasticity, low pressure loss and high particulate loading capacity, reducing respiratory resistance and providing improved comfort and fit to the wearer.

Summary of the Invention

[0002] It is desirable to improve the comfort and performance of respiratory protection devices.

[0003] Described herein is a respirator that includes a layer of a wrinkled medium. The wrinkled medium includes a first series of elastic filaments that are substantially parallel and unbonded between a first nonwoven porous web and a second nonwoven porous web. The first nonwoven porous web is directly bonded to the second nonwoven porous web. At least a portion of the wrinkled medium is resiliently extensible under tension.

[0004] The above summary is not intended to describe each embodiment. Details of one or more embodiments of the invention are also described in the following description. Other features, objects, and advantages will be apparent from the description and claims.

Brief Description of the Drawings

[0005] [Figure 1] FIG. 1 is a schematic view showing a shirred filter medium that may be useful in embodiments herein.

[0006] [Figure 2]Figure 2 is a schematic cross-section of a pleated filter medium, illustrating its structure.

[0007] [Figure 3] Figure 3 is a schematic diagram showing the manufacture of a pleated filter medium according to one embodiment of the present disclosure.

[0008] [Figure 4A] Figure 4A shows a tri-fold respirator according to an embodiment of this specification. [Figure 4B] Figure 4B shows a tri-fold respirator according to an embodiment of this specification. [Figure 4C] Figure 4C shows a tri-fold respirator according to an embodiment of this specification. [Figure 4D] Figure 4D shows a tri-fold respirator according to an embodiment of this specification. [Figure 4E] Figure 4E shows a tri-fold respirator according to an embodiment of this specification. [Figure 4F] Figure 4F shows a tri-fold respirator according to an embodiment of this specification. [Figure 4G] Figure 4G shows a tri-fold respirator according to an embodiment of this specification.

[0009] [Figure 5A] Figure 5A shows a cup-type respirator according to an embodiment of this specification. [Figure 5B] Figure 5B shows a cup-type respirator according to an embodiment of this specification. [Figure 5C] Figure 5C shows a cup-type respirator according to an embodiment of this specification. [Figure 5D] Figure 5D shows a cup-type respirator according to an embodiment of this specification. [Figure 5E] Figure 5E shows a cup-type respirator according to an embodiment of this specification.

[0010] [Figure 6A]FIG. 6A shows a style of a respirator that can benefit from the embodiments of this specification. [Figure 6B] FIG. 6B shows a style of a respirator that can benefit from the embodiments of this specification. [Figure 6C] FIG. 6C shows a style of a respirator that can benefit from the embodiments of this specification.

[0011] [Figure 7] FIG. 7 shows a schematic diagram of a user's face that can benefit from the embodiments of this specification.

[0012] [Figure 8] FIG. 8 shows a method of manufacturing a respiratory protection device according to the embodiments of this specification.

[0013] Those skilled in the art should understand that numerous other modifications and embodiments can be devised that fall within the scope and spirit of the principles of this disclosure. The schematic diagrams may not be drawn to scale.

MODE FOR CARRYING OUT THE INVENTION

[0014] As used herein, the terms "a," "an," and "the" are used interchangeably and mean one or more. Also, "and / or" is used to indicate that both cases described can occur. For example, A and / or B includes (A and B) and (A or B).

[0015] Also, herein, the description of a range by endpoints includes all numerical values included within that range (e.g., 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

[0016] Also, herein, the description of "at least one" includes all numerical values of one or more (e.g., at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.).

[0017] As used herein, "containing at least one of A, B, and C" means element A alone, element B alone, element C alone, A and B, A and C, B and C, and any combination of all three.

[0018] As used herein, the term “respirator” refers to a device that closely covers the face and filters inhaled and exhaled particles and droplets. The respirators described herein may be designed to seal to the user’s face along a continuous sealing perimeter (often called a “racetrack”). Such features distinguish the respirator from cloth face masks, surgical masks, and the like. In some embodiments, the respirators herein include electrically charged fibers that attract particles, thereby increasing the loading capacity.

[0019] Disposable respirators are used in a variety of environments and industries. During the peak of the COVID-19 pandemic, a wide range of types and models of disposable respirators became widespread. The COVID-19 pandemic saw many innovations in the area of ​​increasing the surface area of ​​respirators to reduce pressure loss, thereby decreasing breathing resistance and improving user comfort. Amazon PerfectFit and Airgami® are two of the many different concepts that emerged as a result. However, there is still a need to maintain high particle loading rates while further increasing surface area and reducing breathing resistance to improve comfort. In addition, there is a desire to increase the elasticity of respirators so that a single respirator design can accommodate a wider range of face shapes. Flexible and stretchable filters allow designers to create respirators that adapt to the wearer's facial movements.

[0020] Many different configurations of disposable respirators exist on the market. However, the vast majority have a fixed shape and dimensions and cannot adequately stretch to accommodate the wearer's facial movements, such as yawning, laughing, or talking. In some cases, the respirator may slide or move with the wearer's facial movements, resulting in a poor fit, leakage, or even injury to the wearer's face. Some respirator designs that offer stretchability involve heavy and bulky plastic structures or have limited stretchability due to additional filter media. Embodiments described herein describe flexible and expandable respirator designs that can accommodate a wider range of face sizes.

[0021] Reducing pressure loss as air passes through the respirator's filter medium lowers breathing resistance and improves comfort. The two most common methods for reducing pressure loss are using larger, flat sheets and using pleated packs. The former leads to a bulkier design, while the latter tends to make the respirator rigid and boxy. As described in the embodiments herein, using a wrinkled medium in the respirator provides a larger surface area than a flat, sheet-like medium while maintaining a more compact or lower profile and better conformity than a pleated pack.

[0022] Embodiments herein incorporate, optionally together with a mesh support, a laminate of a functional medium (hereinafter referred to as the wrinkled medium) in the overall respirator design. The wrinkled medium is described in more detail in terms of its function in the Examples section of U.S. Provisional Patent Application 63 / 434365, filed December 21, 2022, and is incorporated herein by reference.

[0023] Wrinkled media differ in several ways from the flat sheets and pleated packs commonly used in respirators. Through the wrinkled surface, they provide a larger surface area in a compact profile. The elastic structure allows for stretching and contraction, potentially enabling a better fit and a more comfortable and adaptable respirator design. Furthermore, some embodiments of this specification include mesh-like open meshes (hereinafter referred to as "skip slits") (e.g., as described in PCT Publication WO2018 / 090280A1) or elastic nets that provide support for wrinkled media along with elasticity to stretching and contraction.

[0024] The respirators in the embodiments of this specification maintain a good fit while exhibiting a unique appearance, low breathing resistance, and expandability. With appropriate respirator design, such as multi-panel or support shell components, the respirators described herein exhibit low pressure loss while maintaining good expandability. In some embodiments, the respirators can also be folded flat.

[0025] The embodiments described herein are in contrast to previous works that use a plastic structure to provide flexibility (but make it bulky and non-foldable) to support an additional filter medium, or use a corrugated medium to reduce breathing resistance (but make it non-flexible and non-foldable).

[0026] Figure 1 shows a top view of a pleated filter medium according to one embodiment of the present disclosure. The pleated filter medium 10 includes a plurality of spaced elastic filaments. The plurality of elastic filaments are sandwiched between two nonwoven porous fiber webs. During the manufacture of the pleated filter medium (hereinafter referred to as the "pleated medium"), the elastic filaments are stretched under tension, and when the tension is released, the nonwoven porous fiber webs contract. Figure 2 shows a side view of the filter medium 20, showing a first nonwoven porous fiber web 24 and a second nonwoven porous fiber web 26 with elastic filaments 22 positioned between them. Figure 2 shows that the first nonwoven porous fiber web 24 is in direct contact with the second nonwoven porous fiber web 26. From the resulting article, if an adhesive is used, the adhesive is expected to bond the two nonwoven porous fiber webs and the filaments between them. The bonding between the first and second nonwoven porous fiber webs is discontinuous, suggesting that the nonwoven porous fiber webs may not be bonded to the filament (e.g., by an adhesive) along its entire length. <Material list - Non-woven media>

[0027] Table 1 shows the nonwoven webs used in the manufacture of pleated media as described in U.S. Provisional Patent Application 63 / 434365, filed December 21, 2022, and Table 2 shows their initial pressure drop (dP) and permeation in NaCl and DOP tests. [Table 1] [Table 2] <Elastic filament>

[0028] The elastic filaments of this application comprise polymers and are inherently elastic—meaning the filament can recover, or at least partially recover, its length after stretching. Rolls of the filaments are available from Invista, Inc. in Wichita, Kansas, under the trademark name "100% Lycra Spandex 235 Multifil," DTEX Type 737, 210 denier. Examples of polymer materials that may be used in the filaments of this application include natural rubber, synthetic rubber, polyether-polyurethane, polyamide, polyisoprene, copolymers of isoprene and neoprene, polymers of 2-chloro-1,3-butadiene, polyether-polyurea copolymers (e.g., Lycra), and polyurethane (e.g., spandex). Other examples include Kraton® copolymers. These are elastomeric triblock polymers comprising a high-Tg end block of polystyrene and a low-Tg center block consisting of one or more such as isoprene and butadiene.

[0029] In one embodiment, the diameter of the filament is at least 1, 5, 10, or 20 micrometers, and at most 25, 50, or 100 micrometers. In one embodiment, the denier of the filament is at least 100, 150, 175, 200, 210, 220, 250, or 500. In one embodiment, the denier of the filament is at most 1200, 900, 800, 700, 600, 500, 400, 350, 300, 250, or 225 denier.

[0030] The effective fiber diameter can be estimated by measuring the pressure loss through a filter of a known material, following the method described in "Air Filtration" by C.N. Davies (Academic, London, 1973). <Nonwoven porous fiber web>

[0031] Multiple elastic filaments are arranged between two nonwoven porous fiber webs—hereinafter referred to as nonwoven webs. The nonwoven webs of this disclosure can be manufactured by wet molding, carding, airlaid, spunlace, spunbond, spunmelt, or melt-blown techniques, or a combination thereof. The nonwoven webs herein can also be formed from fibrillated film fibers. The nonwoven webs herein can also be formed from fibrillated films (for example, those described in U.S. Patent RE32171, published June 3, 1986).

[0032] In some embodiments, nonwoven webs may undergo a relofting process after formation to increase their loftiness. Nonwoven webs may include or be composed of scrim or net. Nonwoven webs may contain nanofibers produced by processes such as electrospinning. Spunbond fibers are formed by extruding molten thermoplastic polymer as filaments from multiple fine, usually circular, capillaries of a spinneret, with the diameter of the extruded fibers rapidly decreasing. Meltblown fibers are formed by extruding molten thermoplastic material as molten threads or filaments through multiple fine, usually circular, die capillaries into a high-speed, usually heated gas (e.g., air) stream—which thins the filaments of the molten thermoplastic material. The meltblown fibers are then carried by the high-speed gas stream and deposited on a collection surface as a web of randomly dispersed meltblown fibers. Any nonwoven web may be made from a single type of fiber or from two or more types of different thermoplastic polymers and / or fibers of different thicknesses.

[0033] Suitable thermoplastic polymer materials include, but are not limited to, polyolefins (e.g., polypropylene or polyethylene), poly(isoprene), poly(butadiene), fluorinated polymers, chlorinated polymers, polyamides, polyimides, polyethers, poly(ethersulfone), poly(sulfone), poly(vinyl acetate), polyesters (e.g., poly(lactic acid)), copolymers of vinyl acetate (e.g., poly(ethylene)-co-poly(vinyl alcohol)), poly(phosphazene), poly(vinyl ester), poly(vinyl ether), poly(vinyl alcohol), and poly(carbonate).

[0034] Suitable polyolefins include, but are not limited to, poly(ethylene), poly(propylene), poly(1-butene), poly-4-methyl-1-butene, copolymers of ethylene and propylene, α-olefin copolymers (e.g., copolymers of ethylene or propylene with 1-butene, 1-hexene, 1-octene, 1-decene), poly(ethylene-co-1-butene) and poly(ethylene-co-1-butene-co-1-hexene).

[0035] Suitable polyamides include, but are not limited to, typical nylon polymers such as poly(iminoadipoyliminohexamethylene), poly(iminoadipoyliminodecamethylene), and polycaprolactam. Suitable polyimides include, but are not limited to, poly(pyromellithimide).

[0036] Suitable poly(ethersulfones) include, but are not limited to, poly(diphenyl ethersulfone) and poly(diphenylsulfone-co-diphenylene oxidesulfone).

[0037] Suitable vinyl acetate copolymers include, but are not limited to, poly(ethylene-co-vinyl acetate) and copolymers in which at least some of the acetate groups are hydrolyzed to provide a variety of poly(vinyl alcohols).

[0038] The fiber selected for a nonwoven web depends on the type of particles being filtered. Particularly useful fibers include meltblown fiber webs, for example, disclosed in Wente, Van A., "Superfine Thermoplastic Fibers", 48 Industrial Engineering Chemistry, 1342 et seq (1956). Meltblown fiber webs provide a particularly excellent filtration layer when used in a continuously electrically charged form (see U.S. Patent No. 4,215,682, Kubik et al.). Preferably, these meltblown fibers are microfibers having an effective diameter of at least 4, 6, 8, or 10 micrometers, and up to 12, 14, 16, or 20 micrometers. Other particularly useful filtration fibers are electrically charged fibrillated film fibers, such as those disclosed in U.S. Patent No. RE 31,285, Van Turnhout. Rosin wool fiber webs and glass fiber webs are also useful, as are solution-spun or electrostatically sprayed fibers, particularly in microfiber form.

[0039] Nonwoven webs are porous, meaning that one outer surface of the nonwoven web is fluidly connected to the opposite outer surface of the same nonwoven web. This allows for the flow of vaporized fluid, air, or liquid through the nonwoven web. Nonwoven webs are coextensive, meaning that the web is a complete and continuous layer of nonwoven material without tears or ruptures.

[0040] In one embodiment, at least one of the nonwoven webs of the present disclosure comprises an electret fiber. An electret is a dielectric material having a quasi-permanent charge or dipole polarization. Electrets are typically improved by incorporating a charging additive into a polymer material and then inducing a charge in the polymer material using corona treatment, tribocharging treatment, hydrocharging treatment, or a combination thereof. In one embodiment, the electret fiber is a single-component fiber. In another embodiment, the electret fiber is a two-component fiber such as a sheath core or side-by-side. In one embodiment, the electret fiber is a sheath core fiber having a sheath layer extending equally on the core. In one embodiment, the core contains an additive that enhances the electrostatic charge. In one embodiment, the sheath contains an additive that enhances the electrostatic charge. In one embodiment, the electret fiber is side-by-side, and the fiber comprises two adjacent components along its length. In one embodiment, the electret fiber is a so-called “island in the sea” extrusion, where multiple fiber cores (i.e., one or more, two, four, or six or more cores) are distributed within a polymer matrix that also forms a sheath.

[0041] Many charge-enhancing additives for creating fiber webs containing electrets are known in the art. Exemplary charge-enhancing additives include pigments, light stabilizers, primary and secondary antioxidants, metal deactivators, hindered amines, hindered phenols, metal salts, phosphate triesters, phosphates, and combinations thereof. Preferably, the charge-enhancing additive is solid at room temperature to prevent migration within the resin and does not decompose at moderate temperatures. In one embodiment, the charge-enhancing additive is solid at temperatures of at least 25, 30, 40, 50, 60, 80, or 100°C. In one embodiment, the charge-enhancing additive does not decompose. For example, when heated to 235°C at a heating rate of 10°C / min using thermogravimetric analysis, there is no significant weight loss (i.e., less than 5%, 1%, or 0.1%) when measured under nitrogen.

[0042] Particularly preferred charge-enhancing additives include hindered amine-based additives, triazine-based additives, and hindered phenol-based additives.

[0043] Specific examples of hindered amine or triazine additives include (poly[[6-(1,1,3,3,-tetramethylbutyl)amino]-s-triazine-2,4-diyl][[(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]]) available from BASF (Ludwigshafen, Germany) under the trademark "CHIMASSORB 944", 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate dimethylsuccinate available from BASF under the trademark "TINUVIN 622", and "TINUVIN 622" Di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl), available from BASF under the trademark "CHIMASSORB 2020", polycondensate of dibutylamine-1,3,5-triazine-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine-N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, available from BASF under the trademark "TINUVIN 1577", and "UVINUL This includes N-substituted aminoaromatic compounds available under "T-150," particularly triamino-substituted compounds, such as 2,4,6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine and 2,4,6-tris-(octadecylamino)triazine, also known as tristearylmelamine ("TSM").

[0044] A hindered phenol additive having a hydroxyl group as its terminal functional group. Hindered phenol additives are not particularly limited, and specific examples include pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (BASF Irganox 1010), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (BASF Irganox 1076), tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate (BASF Irganox 3114), and 3,9-bis-{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro-[5,5]undecane (Sumilizer-GA-80, Sumitomo Chemical Co., Ltd.).

[0045] Additional thermally stable organic triazine compounds or oligomers containing at least one nitrogen atom in addition to the nitrogen atom in the triazine ring are disclosed in U.S. Patents 6,268,495, 5,976,208, 5,968,635, 5,919,847, and 5,908,598 by Rousseau et al.

[0046] Further examples of charge-enhancing additives are provided in U.S. Patent Publication No. 2011 / 0137082 by Li et al., U.S. Patent No. 8,613795 by Li et al., U.S. Patent No. 7,390,351 by Leir et al., U.S. Patent No. 5,057,710 by Nishiura et al., and U.S. Patents No. 4,652,282 and 4,789,504 by Susumu et al., as well as U.S. Patent No. 8,790,449 B2 by Li et al.

[0047] The charge-enhancing additive can be added in any appropriate amount. The charge-enhancing additives of this disclosure may be effective even in relatively small amounts. Typically, the charge-enhancing additive is present in the blend of the thermoplastic resin and the charge-enhancing additive in amounts up to about 10% by weight, and more typically in the range of 0.02 to 5% by weight based on the total weight of the blend. In some embodiments, the charge-enhancing additive is present in the range of 0.1 to 3% by weight, 0.1 to 2% by weight, 0.2 to 1.0% by weight, or 0.25 to 0.5% by weight. <Nonwoven porous web containing membrane and adsorbent>

[0048] Alternatively or additionally, porous membranes can be used instead of and / or in combination with nonwoven fiber webs. The membranes may be polyolefin porous membranes, polyacrylonitrile porous membranes, polycarbonate porous membranes, polyester porous membranes, cellulose ester porous membranes, polyamide porous membranes, polyethersulfone porous membranes, polysulfone porous membranes, polyacrylonitrile nanofiber membranes, PVDF nanofiber membranes, cellulose ester nanofiber membranes, polyvinylacetic acid or alcohol nanofiber membranes, nylon membranes, or polyvinyl butyral nanofiber membranes.

[0049] The membranes can be manufactured, for example, by TIPS (thermal-induced phase separation), SIPS (solvent-induced phase separation), VIPS (vapor-induced phase separation), stretching, track etching, or electrospinning (e.g., PAN fiber membranes).

[0050] Wrinkled membranes can be wrinkled, for example, using the techniques described above with respect to Figures 1-2. In some embodiments, multiple elastic filaments are arranged between the membrane layer and one or more nonwoven porous webs. However, in some embodiments, it has been explicitly considered that multiple elastic filaments are arranged between a first membrane layer and a second membrane layer, and these membrane layers may have the same or different compositions. The membrane layers may include those formed by laminating, bonding, or stacking the membrane with one or more nonwoven webs.

[0051] Alternatively or additionally, the nonwoven porous web may contain an adsorbent material. Adsorbent particles may be located on the surface of the nonwoven web or throughout its entire depth. An example of an adsorbent is untreated or chemically treated activated carbon. Other adsorbents, such as polymer adsorbents, may also be used. <Manufacturing method>

[0052] In one embodiment, the wrinkled filter medium of this application can be manufactured by stretching a first series comprising a plurality of elastic filaments. The filaments are generally not bonded to one another (e.g., the filaments of this disclosure are not scrim). The plurality of elastic filaments of the first series are held together (e.g., using spacers) and each filament is substantially parallel to the others and positioned at a predetermined distance. Generally, substantially parallel filaments should not come into contact with the nearest adjacent filament in the working part of the finished product. In one embodiment, the elastic filaments are held at intervals of at least 2, 4, 5, or 6 filaments per inch. In one embodiment, the elastic filaments are held at intervals of up to 8, 10, 12, 15, 20, or 25 filaments per inch. Generally, the filament spacing is chosen to achieve the desired shirring of the nonwoven web without causing large pressure changes.

[0053] Figure 3 shows an exemplary configuration of the first series of filaments 32, where the filaments are tied at both ends and combs 35 and 37 are used at both ends to hold the filaments substantially parallel. The filaments of the first series are placed between a first nonwoven porous fiber web 34 and a second nonwoven porous fiber web 36. The nonwoven web 36 is placed beneath the stretched parallel filaments so that the adhesive surface is in contact with the filaments. The web 34, sprayed with the second adhesive, is placed on top of the stretched parallel filaments so that the adhesive surface is in contact with the filaments. A corrugated cardboard roller is then used to loosely compress the laminate, removing air pockets and causing the two nonwoven webs to bond to each other with the filaments in between.

[0054] The manual holding of the stretched parallel filaments is released, causing the filaments to relax and the laminated medium (web-adhesive-filament-adhesive-web) to wrinkle. Details of the method for manufacturing the wrinkled medium are described in U.S. Provisional Patent Application 63 / 434365, filed December 21, particularly in paragraphs 0027-0037, which are incorporated herein by reference.

[0055] The filament can be stretched to any desired length. The percentage of stretch used herein is defined as the difference between the length of the stretched filament and the length of the initial relaxed filament, divided by the length of the initial relaxed filament, and converted to a percentage. In one embodiment, the elastic filament stretches beyond 50%, 75%, 100%, 150%, 200%, or 250%. The filament may stretch beyond 250% as long as it does not exceed the elastic limit of deformation or breakage during the manufacture of the wrinkled medium disclosed herein.

[0056] The first and second nonwoven webs are placed on either side of the stretched filament. The first and second nonwoven webs may be the same or different. The nonwoven webs are selected based on the desired performance characteristics. The selected nonwoven webs may differ in terms of composition, base weight, thickness, porosity, etc.

[0057] The first and second nonwoven webs are optionally directly bonded to each other using an adhesive as illustrated below, such that the first nonwoven web is in contact with the second nonwoven web. In some embodiments, an adhesive is used to directly bond (or adhere) the first and second nonwoven webs to each other. Such adhesives may include pressure-sensitive adhesives or hot-melt adhesives. Pressure-sensitive adhesives are known in the art and are generally adhesives that bond when pressure (e.g., finger pressure) is applied at room temperature. Exemplary pressure-sensitive adhesives include natural latex or synthetic polymers such as (meth)acrylate. A commercially available pressure-sensitive adhesive is a spray adhesive traded as "3M Super 77 Multipurpose Adhesive" from 3M Corporation (Maplewood, Minnesota, USA). Hot-melt adhesives are thermoplastic polymers that are heated above their softening point and, when applied to a surface in a softened state, penetrate the surface and solidify to ensure bonding. Examples of hot-melt adhesives include Bostik HM-9041, available from Bostik Inc. (Wowwatosa, Wisconsin, USA), and Tailored HM011BA, available from Tailored Chemical Products Inc. (Hickory, North Carolina, USA). In embodiments of this application, when an adhesive is applied, the weight of the adhesive per unit area is less than the weight of the nonwoven web per unit area. In one embodiment, the weight of the adhesive per unit area is less than 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% of the weight of the nonwoven porous fiber web per unit area in the article. Ideally, the adhesive should not impair the performance of the article and should be shrinkable so that the adhesive can maintain cohesion (or keep the two layers of the nonwoven web bonded) when the stretched filaments relax during manufacturing. In one embodiment, in a wrinkled article, the adhesive is at least 1, 2, 4, 5, or 6 gsm (grams / square meter). In one embodiment, in a wrinkled article, the adhesive is up to 8, 10, 15, 20, 40, 60, 80, or 100 gsm.In another embodiment, the first and second nonwoven webs are directly welded to each other, with the first nonwoven porous fiber web in close contact with the second nonwoven porous fiber web. Such welding techniques are known in the art and include thermal welding or ultrasonic welding.

[0058] After the first and second nonwoven porous fiber webs are joined (or bonded) to each other, the tension of the stretched elastic filaments is released, and the resulting article becomes puckered or shirred, as schematically shown in Figure 1. Typically, after the tension of the stretched elastic filaments is released, it may take several hours to several days for the structure to reach equilibrium and for the shirred article to reach its final wrinkled state. In one embodiment, heat may be used to achieve this stabilization more quickly.

[0059] In addition to the first and second nonwoven webs, an additional layer (e.g., a third layer) may be added to the pleated article to provide additional functionality. The third layer may be added before the tension of the filaments is released, resulting in the third layer also being wrinkled or pleated. In another embodiment, the third layer is added after the tension of the filaments is released, resulting in the third layer being a flat layer bonded to the wrinkled or pleated article. An exemplary third layer includes a cover web, which is a layer used to protect the article beneath it from abrasion, soiling, etc. The third layer may also provide cosmetic and visual functionality.

[0060] In another embodiment, in addition to the first series of elastic filaments, a second series of filaments may be used—the first and second series of elastic filaments arranged non-parallel to each other (e.g., offset by at least 45 or 90 degrees). The pleated article is created in the same manner as described above, except that both series of elastic filaments are placed between two nonwoven webs. When the tension in both series of filaments is released, the resulting article has a more complex wrinkled pattern, as shown in the Examples section.

[0061] In yet another embodiment, the series of elastic filaments may be stretched at different rates, and as a result, when the tension is released, the resulting wrinkled material includes regions with more wrinkles and regions with less wrinkles.

[0062] The articles of this disclosure are elastically stretchable under tension, meaning that when a wrinkled article is pulled in the same direction as the length of the elastic filament, the wrinkled article stretches (or flattens), and when the tension is released, the stretched article returns to its wrinkled shape. In one embodiment, the wrinkled article is elastically stretchable to at least two or three times its relaxed length. In some embodiments, the wrinkled article includes at least one portion that is elastically stretchable under a first tension, and a second portion of the pleated filter medium is under a second tension.

[0063] Because the articles of this disclosure have a wrinkled (or pleated) appearance, the resulting articles have a higher base weight than the original flat or wrinkle-free nonwoven porous fiber web. In one embodiment, the pleated articles of this disclosure have a base weight of at least 10, 15, 20, 30, 40, 50, 75, or 100 grams per square meter (gsm). In one embodiment, the pleated articles of this disclosure have a base weight of up to 100, 125, 150, 175, 180, 200, 225, 250, or 300 gsm.

[0064] The resulting pleated medium is self-supporting—meaning it does not require an additional layer to support a nonwoven web / filament / nonwoven web structure, optionally containing adhesive. Such articles can be used to filter and remove undesirable particles from fluids, such as dust, mold, oily mist aerosols, cigarette smoke, pet dander, viruses, and bacteria.

[0065] The filter media described herein can have a variety of suitable air permeability. In one embodiment, the filter media has an air permeability of 2, 5, 10, 15, 20, 25, 30, 40, 50, 75, 100, 120, 150, 170, 200, 275, 300, 350, 400, or 450 CFM / sqft or higher. In some embodiments, the filter media has an air permeability of 450, 400, 350, 325, 300, 275, 250, 225, 200, 170, 150, 120, 100, 75, 60, 50, 40, 35, 30, or 25 CFM / sqft or lower. Combinations of the above ranges are also possible (for example, 20 CFM / sqft or more and 350 CFM / sqft or less, 35 CFM / sqft or more and 170 CFM / sqft or less, or 20 CFM / sqft or more and 350 CFM / sqft or less). Other ranges are also possible. The air permeability of the filter medium can be determined according to ASTM test standard D737 (1996).

[0066] The results of filtration performance tests of pleated media articles are described in more detail in U.S. Provisional Patent Application No. 63 / 434365, filed on December 21, particularly in the embodiments thereof, and are incorporated herein by reference. <Testing Method>

[0067] Examples of media were evaluated using the following test methods. Unless otherwise specified, at least two samples were tested for each example (EX) and comparative example (CE), and the average was taken.

[0068] Unless otherwise specified, all initial and loaded NaCl permeability and pressure drop tests on the webs were performed at a face velocity of 13.9 cm / sec. The performance of the medium webs listed in Table 3 are actual measurements based on the described test methods.

[0069] The respirator samples were mounted in holders designed for specific respirator types within the corresponding test chambers. For example, horizontal flat folding respirators, such as the Aura respirator, were first removed from the headband and staples where applicable. Next, the flat fold was opened and the respirator was set in an open cylindrical holder with the outlet or downstream side facing upwards. The sides where the headband had been stapled or welded were spread apart and positioned in the two grooves of the cylindrical holder. Optionally, the holder could have a dome-shaped opening to support the respirator. With the respirator fully open and set in the holder, a slightly larger cylindrical ring was pressed around the circumference of the mounted respirator, creating a tight seal by sandwiching the circumference of the respirator between the holder and the ring. The mounted assembly was then placed in a test chamber—which could provide additional pressure during testing to ensure a good seal.

[0070] In another example, a cup-shaped respirator can be mounted in a similar manner to a holder with holder dimensions designed for a specific cup style. The holder with the respirator mounted is placed, aligned, and tested on a test machine such as the TSI® Model 8130 High-Speed ​​Automatic Filter Tester, provided by TSI Inc. (Shoreview, Minnesota, USA). Optionally, larger cup-shaped respirators or cup-shaped respirator samples with expanded circumferences and sufficient mechanical resistance to deformation or collapse under airflow can also be placed directly on the lower chuck of the TSI® Model 8130 High-Speed ​​Automatic Filter Tester, with their outlet or downstream side facing upwards. When the upper chuck is lowered by the test command, the circumference of the respirator is compressed and sealed by the pressure between the upper and lower chucks.

[0071] Other styles of respirators, such as the 3M VFlex® respirator or the vertical flat fold respirator under the trademark name "3M Disposable Respirator 9105 or 9010" provided by 3M (Maplewood, Minnesota, USA), are attached to holders designed specifically for their shapes and sizes and are tested in a similar manner. Respirator holders and test chambers can be made of various materials. Some are chosen for their transparency properties to facilitate the observation of tests. Examples include plexiglass, polycarbonate, acrylic, and polystyrene. <NaCl Initial Test and Quality Factor>

[0072] The pressure loss and transmittance of the respirator can be evaluated using a challenge containing NaCl particles supplied at a flow rate of 85 liters per minute (LPM) and using a TSI® Model 8130 High-Speed Automatic Filter Tester provided by TSI (Shoreview, Minnesota, USA). The pressure loss (dP, mmH2O) passing through the filter medium or filter sample can be measured using an MKS pressure transducer provided by MKS (Andover, Massachusetts, USA).

[0073] For the NaCl instantaneous testing using particles with a diameter of 0.075 μm at 85 liters per minute (LPM), the particles are generated from a 2% NaCl solution and provide an aerosol containing particles at an airborne concentration of approximately 16 - 23 mg / m and the automatic filter tester is operated with both the heater and the particle neutralizer turned on. The NaCl initial transmittance and pressure loss tests last for approximately 19 seconds.

[0074] The NaCl particles are passed through a media sample with a diameter of 11.4 cm or an opening of 102 cm 2 at a rate of 85 LPM.

[0075] The NaCl transmittance is defined by the following formula: Transmittance (%) = (Concentration downstream / Concentration upstream) × 100

[0076] The NaCl transmittance and pressure loss are used to calculate the quality factor "QF" by the following equation:

Equation

[0077] A higher initial QF value indicates better initial filtration performance. A decrease in the QF value effectively correlates with a decrease in filtration performance. <NaCl Loading (Collection) Test>

[0078] The loading test was performed using a TSI (trademark) Model 8130 High-Speed Automatic Filter Tester provided by TSI, Inc. (Shoreview, Minnesota, USA) according to the procedures described in the tester manual. The sample was subjected to a continuous NaCl challenge of 85 LPM with the particle ionization device operating. The flat samples tested had an exposed area of 100.2 cm at a nominal face velocity of 13.9 cm / second for both flat and wrinkled media sheets. 2 The exposed area was 100.2 cm.

[0079] The sample can be loaded with NaCl particles until a predetermined amount of NaCl particles is reached or until the pressure loss reaches a predetermined threshold. A calibrated photometer is used at the inlet and outlet of the filter to measure the particle concentration and the particle transmittance through the filter. <Structure and Performance of the Respirator>

[0080] Figures 4A–4E show a horizontally flat, foldable respirator according to embodiments of the present disclosure. Figures 4A–4E show a respirator comprising three panels: an upper panel that contacts the wearer's nose, a lower panel that contacts the wearer's chin, and a central panel extending between the upper and lower panels. The upper panel is joined to the central panel by a fold, seam, weld or bond along its circumference, the fold, seam, weld or bond extending substantially the same length as the edge of the central panel. The lower panel has an edge defined by a circumference joined to the central panel by a fold, seam, weld or bond, the fold, seam, weld or bond extending substantially the same length as the edge of the central panel. Furthermore, while welds and bonds are discussed, it is explicitly considered that they may not be perfect, and dashed or dot welds or bonds may be used in embodiments of the present disclosure, for example, allowing them to extend along the sealed edge. This type of respirator can be folded flat for storage and use, while still forming a cup-shaped air chamber over the wearer's nose and mouth.

[0081] This respirator design is commonly referred to as a tri-fold respirator, three-panel respirator, flat-fold respirator, or horizontal flat-fold respirator, and these terms may be used interchangeably. The structure of a horizontal flat-fold respirator is described in detail in U.S. Patent No. 6,123,077, issued on September 26, 2000. A horizontal flat-fold respirator with an anti-fog mechanism is described in U.S. Patent No. 9,770,611, issued on September 27, 2017. A horizontal flat-fold respirator may also have a deployment function, as described in U.S. Patent Publication 2008 / 0271740, published on November 6, 2008. A horizontal flat-fold respirator may also include a concave area to improve fit and comfort, as described in U.S. Patent Publication 2008 / 027139, published on November 6, 2008.

[0082] Figures 4A and 4B show a horizontally flat, foldable respirator 100 in which the central panel 110 is made of a wrinkled medium and the upper panel 120 and lower panel 130 are made of a flat nonwoven material. However, it is explicitly considered that one or both of the panels 120 and 130 may be made of a wrinkled medium. For example, a lower panel 130 made of a wrinkled medium can provide additional stretch to the panel 130, as shown in Figures 4C-4E, allowing a wider range of users to wear the respirator 100 securely.

[0083] Figures 4C–4E illustrate the functional advantages of a respirator 140, which is designed similarly to respirator 100 and uses a wrinkled medium as a central panel and another wrinkled medium as a lower panel. In Figure 4C, the wrinkled medium as the central panel is positioned to be generally stretchable from nose to chin, and another wrinkled medium as the lower panel is positioned to be generally stretchable from ear to ear. The wrinkled medium of the lower panel can be further stretched around the wearer's chin to provide a better fit. Figure 4C shows an image 150 of the respirator 140 fitted to the head of a mannequin. Figure 4D shows the respirator 140 in a relaxed position 160, and Figures 4E-1–4E-3 show the respirator 140 in various stretched positions 170A–170C. The central panel had a resting height of 3.5 inches in the relaxed position (distance along lines perpendicular to both edges between the edges joined to the lower and upper panels) and increased to a stretched height of 5 inches in the stretched position 170A. This represents approximately a 40% stretch in the central panel. In a second stretched position 170B, the stretched height 114 was intentionally reduced to approximately 4.5 inches, and the lower panel was stretched to have a hammock-like contour around the wearer's chin. The overall stretched height 124 was approximately 6 inches. This represents approximately a 30% stretch compared to the relaxed height. In another stretched position 170C, the stretched height 114 was intentionally reduced to approximately 4.0 inches, and the lower panel was further stretched to conform to a different shape. It was also possible to stretch both the central and lower panels up to 7 inches in the direction of 114. This represents approximately a 100% stretch.

[0084] Figure 4F shows a different respirator 180, which uses a wrinkled medium as the central and lower panels, with the lower panel being retractable from the nose to the chin. Figure 4G shows a respirator 190, which has a total of four panels, with the three lower panels using a wrinkled medium.

[0085] The wrinkled central panel accommodates individuals with a longer distance from the nose to the chin and provides better fit, especially during facial movements such as talking, laughing, and yawning. In contrast, the height of the non-wrinkled nonwoven panel (e.g., the upper panel) remains virtually unchanged. Similarly, using a wrinkled medium for the lower panel improves the fit to the individual's chin and further enhances adjustability, as seen in the transition between Figure 4E-3 (extended height 124) and 4E-2 (relaxed height 122).

[0086] However, while Figures 4A–4G show a horizontal flat folding respirator with a single wrinkled media panel as the central panel, or two wrinkled media panels as the central and lower panels, or three lower wrinkled media panels, it is explicitly considered that the wrinkled media may exist in various configurations. For example, in some embodiments, both the upper and lower panels may be composed of wrinkled media. In some embodiments, only the upper panel may be composed of wrinkled media. In some embodiments, only the lower panel may be composed of wrinkled media. In some embodiments, the upper and central panels may be composed of wrinkled media. In some embodiments, the central and lower panels may be composed of wrinkled media. In some embodiments, all panels may be composed of wrinkled media. In some embodiments, any panel may have a combination of wrinkled and non-wrinkled media. In some embodiments, the harness (e.g., ear loops or straps for securing the respirator to the wearer's face) may be composed of wrinkled media. In some embodiments, the harness and central panel may be formed from a single wrinkled media article. In some embodiments, a first wrinkled media article may form the upper panel and a first strap, and a second wrinkled media article may form the lower panel and a second strap. The horizontal flat folding respirator may also include other features, including a nose clip on the upper panel to ensure a seal around the wearer's nose, and a foam portion to improve comfort and fit around the wearer's nose. In some embodiments, the upper panel is made of a material that increases pressure loss compared to the middle and lower panels. This may improve anti-fogging properties. In some embodiments, the respirator may include an exhalation valve, such as those described in U.S. Patent No. D746,974 “Exhalation Valve Flap” and U.S. Patent No. 10,905,903 “Respirator Having Optically Activated Exhalation Valve,” which are incorporated herein by reference.The valve is preferably located in the central panel, but may be located in the upper or lower panel of the tri-fold respirator.

[0087] Figures 5A–5E show cup-shaped respirators according to embodiments of the present disclosure. Similar to horizontal flat-fold respirators, attempts have been made to increase the surface area of ​​cup-shaped respirators and reduce breathing resistance to improve comfort. Previous attempts have included adding pleated media to cup-shaped mask designs, as shown in Moldex Design Patent D677779 and U.S. Patent No. 10,834,980.

[0088] Cup-shaped masks 210, 220, and 230 were fabricated with a wrinkled medium and welded to a 3M® respirator 8210 shell. Initial pressure drop and instantaneous penetration percentage were measured in an 85 LPM NaCl challenge and compared with selected respirators without the wrinkled medium. The results are shown in Table 3 below.

[0089] Figures 5A-1 and 5A-2 show the first cup-shaped respirator 210. The respirator 210 is formed from a wrinkled medium and consists of two layers with an effective fiber diameter (EFD) of approximately 7.0 micrometers, has a base weight of 18 grams / square meter (gsm), and has an elongation ratio of 200%, where the elongation ratio indicates the elongation value of the filament during the manufacturing of the wrinkled filter medium.

[0090] Figures 5B-1 and 5B-2 show the second cup-shaped respirator 220. The respirator 220 is formed of a wrinkled medium and consists of two layers with a total weight of approximately 7.0 EFD, a base weight of 18 gsm, and an elongation ratio of 100%.

[0091] Figure 5C-1 shows a third cup-shaped respirator 230. The respirator 230 is formed of a wrinkled medium and consists of two layers with a total weight of approximately 7.0 EFD, a base weight of 18 gsm, and an elongation ratio of 50%.

[0092] Figure 5C-2 shows the fourth cup-shaped respirator 240. The respirator 240 is formed of a wrinkled medium and consists of two layers of approximately 6.5 EFD, has a base weight of 16 gsm and an elongation ratio of 200%.

[0093] Figure 5C-3 shows the fifth cup-shaped respirator 250, which is formed from a wrinkled medium and consists of one layer of fibrillated film fibers with a rectangular cross-section of approximately 10 micrometers × 40 micrometers and one layer of BMF fibers with a base weight of 150 gsm and 7.5 EFD, and a base weight of 61 gsm, with an elongation ratio of 100%.

[0094] Figures 5D-1 and 5D-2 show a sixth cup-shaped respirator 260 with a “skip-slit” formed shell. Generally, cup-shaped respirators require a molding or stamping process to create a permanent “cup” shape. The cup shape provides rigid structural support, reduces the risk of crushing, and improves pressure resistance. The cup-shaped shell layer may be an inner layer (e.g., the face side of 3M® 8210 N95) or an outer layer (e.g., 3M® 8511 N95). As used in this disclosure, the skip-slit shell refers to a three-dimensional respirator shell formed from a mesh-like, two-dimensional continuous nonwoven fabric. The shell has a mesh-like open pattern. The mesh pattern is formed by cutting or slitting the web in a desired pattern. When used with a wrinkled medium, the skip-slit shell allows the cup-shaped respirator to be flexible enough to be substantially flattened for storage and elastic enough to return to its original cup shape (spring back).

[0095] Figure 5D-1 shows a skip-slit shell 262 incorporated into the cup-shaped respirator 260 shown in Figure 5D-2. The skip-slit shell is less rigid than the shell of the 3M® 8210 N95 respirator, but adequately supports the filter medium with improved stretchability and elasticity sufficient to return to its formed shape. The respirator 260 consists of two layers of wrinkled medium with a 7.5 EFD, 61 gsm yield and features a skip-slit forming shell with a 200% elongation ratio.

[0096] Figures 5E-1 and 5E-2 show a mesh shell used in embodiments of the present disclosure. Specifically, Figures 5E-1 and 5E-2 show a shell formed from an elastic net. The shell 272 is elastic and returns to a dome-shaped configuration when flattened. Figures 5E-3 and 5E-4 show the shell 272 integrated into a seventh cup-shaped respirator 270. The cup-shaped respirator 270 contains a wrinkled medium and, in some embodiments, includes a shell formed from an elastic material that forms a cup-shell shape. The elastic net shell 272 is flexible and stretchable and can be crushed for more compact storage when compressed, and is elastic enough to return to its original molded cup shape.

[0097] The wrinkled medium in the embodiment shown in Figure 5E-3 was formed of two layers of BMF medium, having approximately 6.5 EFD of fiber, a base weight of 18 gsm, and an elongation ratio of 200%. The layers were point-bonded to an elastic net shell 272 along the circumference of the cup 270, making the circumference of the cup also stretchable. The respirator 270 shown in Figure 5E-3 had a lateral stationary height 274 of approximately 2 inches and could be stretched to a height of approximately 2.5 inches. The respirator 270 also had a central stationary height (distance from the nose contact point to the chin contact point of the respirator) 276 of approximately 4 inches and could be stretched to approximately 5.5 inches. The ability of the respirator to stretch accommodates the wearer's facial movements when talking, laughing, or yawning, providing better fit and conformity. In the embodiments shown herein, the central resting height of the respirator (measured from the nose contact point to the chin contact point) can be elastically stretched by at least 10%, at least 20%, or at least 30%.

[0098] Additional features may be added to the cup-shaped respirator. For example, elastic fabric material may be added to the sides to enhance comfort and allow for cosmetic identification. In another example, a wrinkled medium may be folded to further increase the surface area.

[0099] Cup-shaped respirators 210, 220, and 230 were designated EX1, EX2, and EX3 in Table 3, respectively. These respirators used a wrinkled medium made of two layers of web F4 with elongation ratios of 200%, 100%, and 50%, respectively. CE1 was a cup-shaped respirator with the trademark name "3M Disposable Respirator 1860" supplied by 3M Corporation (Maplewood, Minnesota, USA). CE2 was a cup-shaped respirator with the trademark name "3M Disposable Respirator 8210" supplied by 3M Corporation (Maplewood, Minnesota, USA). Samples were tested according to initial transmittance, pressure drop, and quality factor tests using NaCl particles. The results are shown in Table 3. [Table 3]

[0100] Cup-shaped respirator 240, designated EX4 in Table 4, was made from a wrinkled medium containing two layers of web F1 with an elongation ratio of 200%. One respirator, shown as EX5 in Table 4, was made from the same two layers of wrinkled medium used in 240. Respirator 270, shown as EX6, was made from the same wrinkled medium used in 240 and a shell made of elastic net. These respirators were tested for initial pressure drop using NaCl particles, and the results are shown in Table 4. [Table 4]

[0101] The cup-shaped respirator 250, shown as EX7 in Table 5, was made from a pleated medium with one layer of web F5 and one layer of web F2 at an elongation ratio of 100%. Initial pressure drop, permeability, and load capacity were tested using NaCl particles. A comparative respirator CE3 was made from the same web F5 and F2 in a non-pleated form. These were tested for initial and load pressure drop and permeability using NaCl testing. The test results are shown in Table 5. [Table 5]

[0102] The Aura®-style respirators 100, 140, and 180 are shown as EX8, EX9, and EX10 in Table 6. Respirator 100 uses a wrinkled medium made of two layers of web F1 with an elongation ratio of 200% as the central panel. Respirator 140 uses the same wrinkled medium as respirator 100, with wrinkled medium as the central and lower panels, and the wrinkles are generally oriented vertically when the respirator is folded flat. Respirator 180 uses the same wrinkled medium as respirator 100, with wrinkled medium as the central and lower panels, and the wrinkles are generally oriented parallel to each other when the respirator is folded flat. CE4 was an Aura®-style respirator with the trademark name "3M Disposable Respirator Aura® 1870+" supplied by 3M Corporation (Maplewood, Minnesota, USA). These samples were tested for initial pressure drop using NaCl particles. The results are shown in Table 6. [Table 6]

[0103] Prototypes 1-3 (Figures 5A-5C) demonstrate lower pressure loss and improved quality coefficients compared to commercially available respirators.

[0104] As shown in Tables 1, 2, and 4, the prototype respirators using wrinkled media exhibited a significant reduction in pressure drop. The pressure drop of the cup-shaped prototype was less than half that of the commercially available 3M cup respirator (less than 3 mmH2O vs. ≥ 8 mmH2O), and the pressure drop of the flat-fold respirator using wrinkled media was approximately half that of the commercially available 3M Aura respirator (approximately 4.5 mmH2O vs. ≥ 8 mmH2O).

[0105] Furthermore, as shown in Table 3, respirators using wrinkled media exhibit a significant decrease in pressure drop (9.2 mmH2O vs. 13.3 mmH2O) and transmittance (0.44% vs. 0.77%) during NaCl particle loading.

[0106] Figures 6A–6C illustrate other respirator styles that may benefit from the introduction of wrinkled media. While embodiments of horizontal flat folding and cup-type respirators are described in detail here, it should be noted that other respirator styles may also benefit from the incorporation of wrinkled media.

[0107] Figure 6A shows a vertically folding respirator 310 designed to fold flat along a crease 312. The respirator 310, according to embodiments of the present disclosure, is composed of a wrinkled medium, which improves elasticity, reduces breathing resistance, and enhances comfort.

[0108] Figure 6B shows a pleated respirator 320 (for example, available from 3M under the trade name VFLEX®), which is shown in U.S. Patent No. 8,640,704, Figures 1-4 and columns 4, 25-5, 29, and is incorporated herein by reference. The pleated respirator 320 can be folded along a center line. The respirator 320 has a mask body with a lateral dividing line and a longitudinal axis. One or more weld patterns are positioned above the dividing line and do not cross the dividing line. One or more weld patterns may be positioned on each side of the longitudinal axis. In some embodiments, one or more additional weld patterns are positioned below the dividing line on each side of the longitudinal axis and do not cross the dividing line. Any, all, or some of the welds are two-dimensional closed patterns. The welding pattern of the respirator 320 may be a truss-like geometric shape, or one or more triangles, with sharp or rounded corners. The welding pattern may also have other shapes. The shape of the welding pattern may exist in multiple sizes, multiple orientations, or both. The shapes may overlap, share edges or corners, or, in some embodiments, be embedded within each other.

[0109] Figure 6C shows a “duckbill” type respirator 330. The “duckbill” type respirator may be similar to that described in Brunson's U.S. Patent No. 5,322,061. Such a respirator is characterized by having a roughly trapezoidal portion that forms an upper half in contact with the wearer’s nose and a roughly trapezoidal portion that forms a lower half in contact with the wearer’s chin.

[0110] Figures 4–6 show several different respirator designs, but it is explicitly considered that other respirator designs may also benefit from incorporating wrinkled media. For example, a one-piece mask formed without welding, joining, or sewing different panels (as shown in Tsuei's U.S. Patent Publication 2015 / 0173436). In another example, wrinkled media can be used in a reusable respirator available from 3M (Maplewood, Minnesota, USA) under the trade name "3M Reusable Respirator 7744 or 7711K." The media with the wrinkled layer is surrounded by a respirator holder. The media is replaceable, while the respirator holder or case is reusable. Other respirator designs are also considered.

[0111] The respirators described and shown in Figures 4-6 are composed of multiple material layers, some or all of which may consist of a wrinkled medium. The layers of the respirator may be joined by welding, spot welding, bonding, spot bonding, seams, or other suitable methods. In some embodiments, the wrinkled medium is combined with a flat sheet medium and / or a pleated pack to maximize the advantages of each medium configuration. In some embodiments, the respirator models shown herein include a wrinkled medium in a face-sealing area that can absorb sweat and improve comfort. In some embodiments, the respirators described herein may include an anti-fog band along the top of the respirator to prevent the eyewear from fogging up. In some embodiments, the respirators shown herein include a fixing tape along the nose area to improve the fit by preventing movement of the respirator along the bridge of the nose. In some embodiments, the respirators shown herein include a breathing or exhalation valve. In some embodiments, the respirators shown herein include a headband, straps, and / or ear loops.

[0112] The respirators shown here are depicted with white filaments on a wrinkled medium, but the use of natural-colored or dyed filaments is also explicitly considered, for example, to visually distinguish the respirator models.

[0113] Figure 7 shows a typical respirator wearer who may benefit from the embodiments described herein. The respirator needs to be completely sealed (tightly fitted) to the face 700 for it to be effective. The perimeter of the seal is called the racetrack 710. In currently available masks, the racetrack 710 of a particular respirator model does not change substantially because the media layer does not stretch significantly. Furthermore, in most respirators, the media layer is sealed together so that the racetrack cannot expand significantly.

[0114] However, the embodiments shown herein are made of a wrinkled medium and, as shown in Figures 4D-4E, have significant elasticity, allowing the wearer 700 to change the shape and circumference of the racetrack 710 as indicated by the arrow 720. The wearer 700 can linearly stretch the respirator along, for example, an axis 730. This can cause the respirator to stretch further to cover the wearer's chin, potentially improving comfort.

[0115] Disposable respirators, composed of different layers or panels, are generally sealed along their perimeter to ensure that air is allowed to pass through the filter material. Sealing is often achieved by welding, joining, or sewing. However, in some embodiments shown here, spot welding or spot joining is used to produce a sufficient seal while allowing the respirator to stretch. In some embodiments, elastic filaments are used to form seams, allowing the elastic filaments to stretch along with the wrinkled medium.

[0116] In some embodiments, the respirator is stretchable enough to increase the racetrack circumference by at least 10% and resilient enough to return to its original size. In some embodiments, the respirator is stretchable enough to increase the racetrack circumference by at least 20%, at least 30%, at least 40%, or at least 50%, and resilient enough to return to its original size. In some embodiments, the respirator is stretchable enough to increase the racetrack circumference by at least 60%, at least 70%, at least 80%, or at least 90%, and resilient enough to return to its original size. In some embodiments, the respirator is stretchable enough to increase the racetrack circumference by at least 100%, and resilient enough to return to its original size.

[0117] The elasticity of respirator models varies. For example, a cup-shaped respirator may be less elastic than other models due to its cup shape. In some embodiments, the racetrack circumference of the cup-shaped respirator shown herein may increase by at least 10%, at least 20%, at least 30%, or at least 40%, and have sufficient elasticity to return to its original size.

[0118] In some embodiments, the length of the respirator, measured from the sealing contact point on the bridge of the nose to the sealing contact point at the center of the chin, may stretch by 10% or more and have sufficient elasticity to return to its original length.

[0119] Figure 8 shows a method for manufacturing a respiratory protection device according to the embodiment shown herein. Method 800 can be used to manufacture any of the respirator types shown in Figures 4-7.

[0120] In block 810, the respirator medium is acquired. A wrinkled medium 812 may be acquired for one or more layers or panels. A flat medium 814 may be acquired for one or more layers or panels. Other mediums 816 may also be used. For example, a medium with anti-fogging properties may be acquired for part of the respirator. Alternatively, a skip-slip layer may be acquired to be used as a shell.

[0121] In block 820, one or more processes are performed on one or more layers. For example, a cup shell may be preformed 822. One or more layers may be charged 824 to exhibit electret properties that attract and bind particles or droplets. Other processes 826 may be performed.

[0122] The preforming process required for cup-shaped respirators involves forming curves in multiple directions, which may include cutting and welding sine waves, potentially limiting the manufacturing speed of the respirator. It should be noted that in some embodiments shown here, a dashed slit layer (sometimes called a skip slit layer) is used to form the cup-shaped structure, eliminating the need for a preforming process.

[0123] The dashed slit layer consists of a surface cut (e.g., slit) in a dashed pattern. An example is shown in Figure 5D-1. However, while the dashed pattern in Figure 5D-1 includes dashes where adjacent lines are offset from each other, it is explicitly considered that other patterns are also possible. U.S. Patent Publication 2019 / 0187345A1 describes numerous patterns that may be used in the embodiments shown herein. The slit pattern may be a diamond slit pattern, for example, as shown in Figures 1-4 and 12 of U.S. Patent Publication 2019 / 0187345A1, which are incorporated herein by reference. The slit pattern may also have a non-diamond slit pattern that allows extension in at least one direction, for example, as shown in Figures 5, 8, 10, 11 and 14 of U.S. Patent Publication 2019 / 0187345A1, which are incorporated herein by reference. The slit pattern may also have two openings of different sizes or shapes, as shown in Figures 6 and 15 of U.S. Patent Publication 2019 / 0187345A1, which are incorporated herein by reference. The slit pattern may also have three openings of different sizes or shapes, as shown in Figures 7, 9 and 13 of U.S. Patent Publication 2019 / 0187345A1, which are incorporated herein by reference. The slit pattern may also have two openings of different sizes or shapes that allow expansion in two directions, as shown in Figures 16 and 18 of U.S. Patent Publication 2019 / 0187345A1. The slit pattern may also have three openings of different sizes or shapes that converge to provide expansion in at least three directions, as shown in Figure 19 of U.S. Patent Publication 2019 / 0187345A1.

[0124] However, although Figure 5D-1 shows a dashed, slit layer that can be used as a shell, other solutions can also be used. In some embodiments, an elastic net can be used as the shell. The elastic net can be formed by molding, extrusion, or other suitable methods.

[0125] In block 830, a layer stack is formed. The layer stack may consist of one or more filter layers 832. The layer stack may include a cover web 834. The layer stack may include a shell 836, such as a skip-slit shell, a corrugated shell, or other suitable shell component. The layer stack may include a layer 838 incorporating an adsorbent capable of adsorbing or absorbing gases, vapors, etc. An example of an adsorbent commonly used for filtration is activated carbon. The layer with activated carbon may be a wrinkled medium layer. The activated carbon layer may be another layer, for example, carbon or other suitable adsorbent attached to the surface of the fiber web. Other layers 839 may include a liquid-resistant layer or a stiffening layer. Although activated carbon is described here as one adsorbent, it is explicitly considered that other adsorbents may also be suitable. For example, polymer adsorbents may be used in the embodiments shown herein.

[0126] In block 840, the layer stack is sealed. Sealing of the layer stack may include welding 842, seams 844, joining 846, or other suitable methods 848. Furthermore, although welding 842 and joining 844 are shown, it is explicitly considered that these are not complete, and for example, dashed or dot welding or joining is used in the embodiments shown herein to allow stretching along the sealed edge. Similarly, if stretching along the sealed edge is desired, seams 844 may include elastic filaments. The sealing is performed so that each layer is in close contact with the adjacent layer. Suitable welding techniques are known in the art and include thermal bonding and ultrasonic welding.

[0127] In block 850, accessories are added. A nose clip 852 may be applied. The nose clip serves to shape the respirator to form a seal with the wearer's face along the nose portion of the racetrack. The nose clip 852 may include a moldable metal or plastic strip or other suitable mechanism. A foam section 854 may also be added to enhance comfort and improve the seal. For example, a custom nose foam is described in PCT Publication WO2022 / 235472, published November 10, 2022, but other types and locations of foam are also considered. An exhaust valve 856 may be added. In some embodiments, the portion of the respirator including the valve is less elastic than the portion without the valve. A harness 858 may be used to bring the respirator into contact with the wearer's face. In some embodiments, the harness 858 may include straps or ear loops integrated with the wrinkled medial layer of the respirator. In some embodiments, the harness 858 may be another component welded, stapled, glued, or otherwise bonded to the respirator body. Other accessories (859) may also be added.

[0128] Wrinkled media are a novel structured input filtration material for respirators. This allows for a larger surface area in a compact profile. With appropriate respirator designs such as multi-panel or support shells, the resulting respirators can have low breathing resistance, high particle loading capacity, and good stretchability. In some embodiments, it is also possible to fold the respirator flat. This is an improvement over previous respirator designs, which either used plastic structures to support additional filter media and provide stretchability (bulky and unable to fold) or used corrugated media to help with breathing resistance (unable to stretch and fold).

[0129] Wrinkled media can be used in many disposable respirator models to improve breathability while maintaining filter capacity. Examples of respirator models that may benefit from wrinkled media include tri-fold respirators (shown in Figures 4A–4E), cup-shaped respirators (shown in Figures 5A–5E), vertical-fold respirators (shown in Figure 6A), flat-fold respirators, pleated respirators (shown in Figure 6B), and "duckbill" respirators (shown in Figure 6C).

[0130] By using a wrinkled medium to form one or more layers of the respirator, the respirator can have a compact, high-surface-area filter, improving comfort and flexibility.

[0131] Predictable modifications and changes to this invention—without departing from the scope and spirit of the invention—will be apparent to those skilled in the art. The invention should not be limited to the embodiments described herein for illustrative purposes. In the event of any inconsistency or conflict between the description herein and any disclosure of any document incorporated herein by reference or reference, the description herein shall prevail.

[0132] A horizontally flat, foldable respirator is presented, comprising a layer of wrinkled medium. The wrinkled medium includes a first series of substantially parallel and unbonded elastic filaments between first and second nonwoven porous webs. The first nonwoven porous web is directly bonded to the second nonwoven porous web. At least a portion of the wrinkled medium is elastically stretchable under tension.

[0133] The respirator further includes an upper panel configured to seal around the user's nose, a lower panel configured to seal around the user's chin, and a central panel, the central panel having an upper and lower edge, the central panel sealing to the upper panel along its upper edge, and the central panel sealing to the lower panel along its lower edge.

[0134] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 10% longer than the resting height.

[0135] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 30% longer than the resting height.

[0136] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 40% longer than the resting height.

[0137] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 6 mmH2O.

[0138] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 5 mmH2O.

[0139] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 4 mmH2O.

[0140] The respirator may be constructed such that the quality factor exceeds 2 at an airflow rate of 85 LPM.

[0141] The respirator may be constructed such that the quality factor exceeds 2.2 at an airflow rate of 85 LPM.

[0142] The respirator may be constructed such that the quality factor exceeds 1.8 at an airflow rate of 85 LPM.

[0143] The respirator may be constructed such that the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

[0144] The respirator may be constructed such that the central panel includes a layer of wrinkled media.

[0145] The respirator may be constructed such that two of the upper, lower, and central panels include layers of wrinkled media.

[0146] The respirator may be constructed such that one of the upper panel, lower panel, and central panel contains a wrinkle-free nonwoven material.

[0147] The respirator may be constructed such that one of the upper panel, lower panel, and central panel contains both a wrinkled nonwoven material and a smooth nonwoven material.

[0148] The respirator may be constructed to include a shell layer having an elastic material.

[0149] The respirator may be constructed such that the shell layer includes a mesh-like material.

[0150] The respirator may be constructed such that the shell layer includes dashed slits.

[0151] The respirator may be constructed such that the shell layer includes an elastic net.

[0152] The respirator may be constructed such that the shell contains extruded material.

[0153] The respirator may be constructed such that the extended perimeter of the respirator is 10% longer than the stationary perimeter of the racetrack.

[0154] The respirator may be constructed such that the extended perimeter of the respirator is 20% longer than the stationary perimeter of the racetrack.

[0155] The respirator may be constructed such that the extended perimeter of the respirator is 30% longer than the stationary perimeter of the racetrack.

[0156] The respirator may be constructed such that the extended perimeter of the respirator is 40% longer than the stationary perimeter of the racetrack.

[0157] The respirator may be constructed such that the extended perimeter of the respirator is 50% longer than the stationary perimeter of the racetrack.

[0158] The respirator may be constructed such that the extended perimeter of the respirator is 60% longer than the stationary perimeter of the racetrack.

[0159] The respirator may be constructed such that the extended perimeter of the respirator is 70% longer than the stationary perimeter of the racetrack.

[0160] The respirator may be constructed such that the extended perimeter of the respirator is 80% longer than the stationary perimeter of the racetrack.

[0161] The respirator may be constructed such that the extended perimeter of the respirator is 90% longer than the stationary perimeter of the racetrack.

[0162] The respirator may be constructed such that the extended perimeter of the respirator is 100% longer than the stationary perimeter of the racetrack.

[0163] The respirator may be constructed to include a hardening layer.

[0164] The respirator may be constructed to include adsorbent particles.

[0165] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane.

[0166] The respirator may be constructed such that one of the first and second nonwoven layers contains a fibrous nonwoven material.

[0167] The respirator may be constructed to include a cover web layer.

[0168] The respirator may be constructed such that the seal is welded, spot welded, joined, spot joined, or stitched.

[0169] The respirator may be constructed such that the seal substantially suppresses elongation along the edges.

[0170] The respirator may be constructed such that the seal does not substantially suppress elongation along the edges.

[0171] The respirator may be constructed to include a nose clip, foam layer, valve, or harness.

[0172] The respirator may include straps, which may be constructed to combine with either an upper, lower, or central panel to form a single, integrated article of the wrinkled medium.

[0173] A cup-shaped respirator is presented, comprising a layer of wrinkled medium. The wrinkled medium includes a first series of substantially parallel and unbonded elastic filaments between first and second nonwoven porous webs. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous web. At least a portion of the wrinkled medium is elastically stretchable under tension.

[0174] The respirator may be constructed to include a forming portion that curves in multiple directions in its initial state.

[0175] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 10% longer than the resting height.

[0176] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 30% longer than the resting height.

[0177] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 40% longer than the resting height.

[0178] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 3.0 mmH2O.

[0179] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 2.8 mmH2O.

[0180] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 2.7 mmH2O.

[0181] The respirator may be constructed such that the quality factor exceeds 2 at an airflow rate of 85 LPM.

[0182] The respirator may be constructed such that the quality factor exceeds 2.2 at an airflow rate of 85 LPM.

[0183] The respirator may be constructed such that the quality factor exceeds 1.8 at an airflow rate of 85 LPM.

[0184] The respirator may be constructed such that the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

[0185] The respirator may be constructed such that the quality factor exceeds 2.4 at an airflow rate of 85 LPM.

[0186] The respirator may be constructed such that the quality factor exceeds 2.5 at an airflow rate of 85 LPM.

[0187] The respirator may be constructed to include a shell layer.

[0188] The respirator may be constructed such that the shell layer is the outer layer.

[0189] The respirator may be constructed such that the shell layer is the inner layer.

[0190] The respirator may be constructed such that the shell layer includes a mesh-like material.

[0191] The respirator may be constructed such that the shell layer includes dashed slits.

[0192] The respirator may be constructed such that the shell layer includes an elastic net.

[0193] The respirator may be constructed to be elastic so that the curvature recovers after a force is applied to the curvature.

[0194] The respirator may be constructed such that the distance over which the respirator is positioned on the racetrack is 10% longer than the distance over which the racetrack is stationary.

[0195] The respirator may be constructed such that the extended perimeter of the respirator is 20% longer than the stationary perimeter of the racetrack.

[0196] The respirator may be constructed such that the extended perimeter of the respirator is 30% longer than the stationary perimeter of the racetrack.

[0197] The respirator may be constructed such that the extended perimeter of the respirator is 40% longer than the stationary perimeter of the racetrack.

[0198] The respirator may be constructed to include adsorbent particles.

[0199] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane.

[0200] The respirator may be constructed such that one of the first and second nonwoven layers contains a fibrous nonwoven material.

[0201] The respirator may be constructed to include a cover web layer.

[0202] The respirator may be constructed to include a nose clip, foam layer, valve, or harness.

[0203] The respirator may include a strap, which may be constructed such that the strap is combined with a layer of wrinkled media to form a single article of wrinkled media.

[0204] A vertically foldable respirator is presented, comprising a layer of wrinkled medium. The wrinkled medium includes a first series of substantially parallel and unbonded elastic filaments between first and second nonwoven porous fiber webs. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous fiber web. At least a portion of the wrinkled medium is elastically stretchable under tension.

[0205] The respirator may be constructed to fold flat along a center line.

[0206] The respirator may be constructed to be able to extend from its resting length to its extended length, recover to its resting length, and have its extended length be 10% longer than its resting length.

[0207] The respirator may be constructed such that the extended perimeter of the respirator is 20% longer than the stationary perimeter of the racetrack.

[0208] The respirator may be constructed such that the extended perimeter of the respirator is 30% longer than the stationary perimeter of the racetrack.

[0209] The respirator may be constructed such that the extended perimeter of the respirator is 40% longer than the stationary perimeter of the racetrack.

[0210] The respirator may be constructed such that the extended perimeter of the respirator is 50% longer than the stationary perimeter of the racetrack.

[0211] The respirator may be constructed such that the extended perimeter of the respirator is 60% longer than the stationary perimeter of the racetrack.

[0212] The respirator may be constructed such that the extended perimeter of the respirator is 70% longer than the stationary perimeter of the racetrack.

[0213] The respirator may be constructed such that the extended perimeter of the respirator is 80% longer than the stationary perimeter of the racetrack.

[0214] The respirator may be constructed such that the extended perimeter of the respirator is 90% longer than the stationary perimeter of the racetrack.

[0215] The respirator may be constructed such that the extended perimeter of the respirator is 100% longer than the stationary perimeter of the racetrack.

[0216] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 3.0 mmH2O.

[0217] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 2.8 mmH2O.

[0218] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 2.7 mmH2O.

[0219] The respirator may be constructed such that the quality factor exceeds 2 at an airflow rate of 85 LPM.

[0220] The respirator may be constructed such that the quality factor exceeds 2.2 at an airflow rate of 85 LPM.

[0221] The respirator may be constructed such that the quality factor exceeds 1.8 at an airflow rate of 85 LPM.

[0222] The respirator may be constructed such that the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

[0223] The respirator may be constructed such that the quality factor exceeds 2.4 at an airflow rate of 85 LPM.

[0224] The respirator may be constructed such that the quality factor exceeds 2.5 at an airflow rate of 85 LPM.

[0225] The respirator may be constructed to include a shell layer.

[0226] The respirator may be constructed such that the shell layer is the outer layer.

[0227] The respirator may be constructed such that the shell layer is the inner layer.

[0228] The respirator may be constructed such that the shell layer includes a mesh-like material.

[0229] The respirator may be constructed such that the shell layer includes dashed slits.

[0230] The respirator may be constructed such that the shell layer includes an elastic net.

[0231] The respirator may be constructed such that the shell layer includes an extruded net.

[0232] The respirator may be constructed such that the extended perimeter of the respirator is 10% longer than the stationary perimeter of the racetrack.

[0233] The respirator may be constructed to include adsorbent particles.

[0234] The respirator may be constructed to include a cover web layer.

[0235] The respirator may be constructed to include a nose clip, foam layer, valve, or harness.

[0236] The respirator may include a strap, which may be constructed such that the strap is combined with a layer of wrinkled media to form a single article of wrinkled media.

[0237] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane.

[0238] The respirator may be constructed such that one of the first and second nonwoven layers contains a fibrous nonwoven material.

[0239] A duckbill-type respirator is presented, comprising a layer of wrinkled medium. The wrinkled medium includes a first series of substantially parallel and unbonded elastic filaments between first and second nonwoven porous fiber webs. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous fiber web. At least a portion of the wrinkled medium is elastically stretchable under tension.

[0240] The respirator may be constructed to fold flat along a center line.

[0241] The respirator may be constructed to include a first roughly trapezoidal portion configured to contact the wearer's nose and a second roughly trapezoidal portion configured to contact the wearer's chin. One of the first and second roughly trapezoidal portions includes a layer of wrinkled medium.

[0242] The respirator may be constructed to be able to extend from its resting length to its extended length, recover to its resting length, and have its extended length be 10% longer than its resting length.

[0243] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 30% longer than the resting height.

[0244] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 40% longer than the resting height.

[0245] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 3.0 mmH2O.

[0246] The respirator may be constructed such that the quality factor exceeds 2 at an airflow rate of 85 LPM.

[0247] The respirator may be constructed such that the quality factor exceeds 2.2 at an airflow rate of 85 LPM.

[0248] The respirator may be constructed such that the quality factor exceeds 1.8 at an airflow rate of 85 LPM.

[0249] The respirator may be constructed such that the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

[0250] The respirator may be constructed such that the quality factor exceeds 2.4 at an airflow rate of 85 LPM.

[0251] The respirator may be constructed such that the quality factor exceeds 2.5 at an airflow rate of 85 LPM.

[0252] The respirator may be constructed to include a shell layer.

[0253] The respirator may be constructed such that the shell layer is the outer layer.

[0254] The respirator may be constructed such that the shell layer is the inner layer.

[0255] The respirator may be constructed such that the shell layer includes a mesh-like material.

[0256] The respirator may be constructed such that the shell layer includes dashed slits.

[0257] The respirator may be constructed such that the shell layer includes an elastic net.

[0258] The respirator may be constructed such that the elastic net is an extruded elastic net.

[0259] The respirator may be constructed such that the extended perimeter of the respirator is 10% longer than the stationary perimeter of the racetrack.

[0260] The respirator may be constructed such that the extended race track circumference of the respirator is 20% longer than the stationary race track circumference.

[0261] The respirator may be constructed such that the extended race track circumference of the respirator is 30% longer than the stationary race track circumference.

[0262] The respirator may be constructed such that the extended race track circumference of the respirator is 40% longer than the stationary race track circumference.

[0263] The respirator may be constructed such that the extended race track circumference of the respirator is 50% longer than the stationary race track circumference.

[0264] The respirator may be constructed such that the extended race track circumference of the respirator is 60% longer than the stationary race track circumference.

[0265] The respirator may be constructed such that the extended race track circumference of the respirator is 70% longer than the stationary race track circumference.

[0266] The respirator may be constructed such that the extended race track circumference of the respirator is 80% longer than the stationary race track circumference.

[0267] The respirator may be constructed such that the extended race track circumference of the respirator is 90% longer than the stationary race track circumference.

[0268] The respirator may be constructed such that the extended race track circumference of the respirator is 100% longer than the stationary race track circumference.

[0269] The respirator may be constructed to include an adsorbent layer.

[0270] The respirator may be constructed to include a cover web layer.

[0271] The respirator may be constructed to include a nose clip, a foam layer, a valve, or a harness.

[0272] The respirator may include a strap, and the strap may be combined with a layer of wrinkled media to form an integral article of wrinkled media.

[0273] The respirator may be constructed such that one of the first and second non-woven layers includes a membrane.

[0274] The respirator may be constructed such that one of the first and second non-woven layers includes a fibrous non-woven material.

[0275] A pleated respirator including a layer of wrinkled media is presented. The wrinkled media includes a first series of elastic filaments that are substantially parallel and unbonded between a first and a second non-woven porous fiber web. The first non-woven porous fiber web is directly bonded to the second non-woven porous fiber web. At least a portion of the wrinkled media is elastically stretchable under tension.

[0276] The respirator may further include a mask body having a laterally extending dividing line, a longitudinal axis, first and second welding patterns respectively disposed above the dividing line on each side of the longitudinal axis and not crossing the dividing line, and third and fourth welding patterns respectively disposed below the dividing line on each side of the longitudinal axis and not crossing the dividing line. Each of the first, second, third, and fourth welding patterns is a two-dimensional closed pattern.

[0277] The respirator may be constructed to be configured to fold flat along a center line.

[0278] The respirator may be constructed to be able to extend from its resting length to its extended length, recover to its resting length, and have its extended length be 10% longer than its resting length.

[0279] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 30% longer than the resting height.

[0280] The respirator may be constructed to extend from a resting height to an extended height, recover to the resting height, and the extended height to be at least 40% longer than the resting height.

[0281] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 3.0 mmH2O.

[0282] The respirator may be constructed such that the quality factor exceeds 2 at an airflow rate of 85 LPM.

[0283] The respirator may be constructed such that the quality factor exceeds 2.2 at an airflow rate of 85 LPM.

[0284] The respirator may be constructed such that the quality factor exceeds 1.8 at an airflow rate of 85 LPM.

[0285] The respirator may be constructed such that the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

[0286] The respirator may be constructed such that the quality factor exceeds 2.4 at an airflow rate of 85 LPM.

[0287] The respirator may be constructed such that the quality factor exceeds 2.5 at an airflow rate of 85 LPM.

[0288] The respirator may be constructed to include a shell layer.

[0289] The respirator may be constructed such that the shell layer is the outer layer.

[0290] The respirator may be constructed such that the shell layer is the inner layer.

[0291] The respirator may be constructed such that the shell layer includes a mesh material.

[0292] The respirator may be constructed such that the shell layer includes a dashed slit.

[0293] The respirator may be constructed such that the shell layer includes an extruded net.

[0294] The respirator may be constructed such that the elastic net is an extruded elastic net.

[0295] The respirator may be constructed such that the extended race track circumference of the respirator is 10% longer than the stationary race track circumference.

[0296] The respirator may be constructed to also include an adsorbent layer.

[0297] The respirator may be constructed to also include a cover web layer.

[0298] The respirator may be constructed to also include a nose clip, a foam layer, a valve, or a harness.

[0299] The respirator may be constructed to include a strap.

[0300] The respirator may be constructed such that one of the first and second non-woven layers includes a membrane.

[0301] The respirator may be constructed such that one of the first and second non-woven layers includes a fibrous non-woven material.

[0302] The respirator may be constructed such that the extended perimeter of the respirator is 10% longer than the stationary perimeter of the racetrack.

[0303] The respirator may be constructed such that the extended perimeter of the respirator is 20% longer than the stationary perimeter of the racetrack.

[0304] The respirator may be constructed such that the extended perimeter of the respirator is 30% longer than the stationary perimeter of the racetrack.

[0305] The respirator may be constructed such that the extended perimeter of the respirator is 40% longer than the stationary perimeter of the racetrack.

[0306] The respirator may be constructed such that the extended perimeter of the respirator is 50% longer than the stationary perimeter of the racetrack.

[0307] The respirator may be constructed such that the extended perimeter of the respirator is 60% longer than the stationary perimeter of the racetrack.

[0308] The respirator may be constructed such that the extended perimeter of the respirator is 70% longer than the stationary perimeter of the racetrack.

[0309] The respirator may be constructed such that the extended perimeter of the respirator is 80% longer than the stationary perimeter of the racetrack.

[0310] The respirator may be constructed such that the extended perimeter of the respirator is 90% longer than the stationary perimeter of the racetrack.

[0311] The respirator may be constructed such that the extended perimeter of the respirator is 100% longer than the stationary perimeter of the racetrack.

[0312] A method for manufacturing a respirator is presented, comprising obtaining a wrinkled media article and forming a laminate of media layers. The wrinkled media article is a wrinkled layer within the laminate of media layers. The method also comprises sealing the laminate of media layers. When sealed, the laminate of media layers has a length of static racetrack circumference and can be elastically stretched to an extended racetrack circumference, which is 10% larger than the static racetrack circumference.

[0313] The method may be carried out to include preforming a laminate of media layers. The preform forms the laminate of media layers into a cup shape.

[0314] The method may be carried out such that one layer of the media layer lamination includes a shell layer.

[0315] The method may be carried out such that the shell layer is an outer layer relative to the wrinkled layer.

[0316] The method may be carried out such that the shell layer is an inner layer relative to the wrinkled layer.

[0317] The method may be carried out such that the shell layer includes a network of open meshes.

[0318] The respirator may be constructed such that the shell layer includes dashed slits.

[0319] The respirator may be constructed such that the shell layer includes an extruded net.

[0320] The method may be carried out such that the shell layer has a stationary shape and the force deforms the stationary shape and then returns it to the stationary shape.

[0321] The method may be carried out to include adding a nose clip, foam layer, valve, or harness to the media layer laminate either before or after sealing.

[0322] The method may be carried out such that sealing involves welding, spot welding, joining, spot joining, or forming a seam.

[0323] The method may be carried out such that the laminate of layers further includes a cover web, an adsorbent layer, a filter layer, or a shell layer.

[0324] The method may be carried out to include charging the wrinkled filter layer.

[0325] The method may be carried out to include charging all additional filter layers of the respirator.

[0326] The method may be implemented such that the respirator is a horizontal tri-fold respirator.

[0327] The method may be implemented such that the respirator is a vertically folding respirator.

[0328] The method may be carried out such that the respirator is a cup-type respirator.

[0329] The method may be carried out such that the respirator is a pleated respirator.

[0330] The method may be carried out such that the respirator is a duckbill-type respirator.

[0331] The method may be carried out such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 3.0 mmH2O.

[0332] The method may be carried out such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 2.8 mmH2O.

[0333] The method may be carried out such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is less than 2.7 mmH2O.

[0334] The method may be carried out such that the quality factor of the respirator exceeds 2 at an airflow rate of 85 LPM.

[0335] The method may be implemented such that the quality factor of the respirator exceeds 2.2 at an airflow rate of 85 LPM.

[0336] The method may be implemented such that the quality factor of the respirator exceeds 1.8 at an airflow rate of 85 LPM.

[0337] The method may be implemented such that the quality factor of the respirator exceeds 1.6 at an airflow rate of 85 LPM.

[0338] The method may be implemented such that the quality factor of the respirator exceeds 2.4 at an airflow rate of 85 LPM.

[0339] The method may be implemented such that the quality factor of the respirator exceeds 2.5 at an airflow rate of 85 LPM.

[0340] The method may be implemented such that the extended perimeter of the respirator is 20% longer than the stationary perimeter of the racetrack.

[0341] The method may be implemented such that the extended perimeter of the respirator is 30% longer than the stationary perimeter of the racetrack.

[0342] The method may be implemented such that the extended perimeter of the respirator is 40% longer than the stationary perimeter of the racetrack.

[0343] The method may be implemented such that the extended perimeter of the respirator is 50% longer than the stationary perimeter of the racetrack.

[0344] The method may be implemented such that the extended perimeter of the respirator is 60% longer than the stationary perimeter of the racetrack.

[0345] The method may be implemented such that the extended perimeter of the respirator is 70% longer than the stationary perimeter of the racetrack.

[0346] The method may be implemented such that the extended perimeter of the respirator is 80% longer than the stationary perimeter of the racetrack.

[0347] The method may be implemented such that the extended perimeter of the respirator is 90% longer than the stationary perimeter of the racetrack.

[0348] The method may be implemented such that the extended perimeter of the respirator is 100% longer than the stationary perimeter of the racetrack.

[0349] The method may be carried out such that one of the first and second nonwoven layers includes a membrane.

[0350] The method may be carried out such that one of the first and second nonwoven layers includes a fibrous nonwoven material.

[0351] A respirator containing a layer of wrinkled media is presented.

[0352] The respirator can be extended from its resting height to its extended height, recover to its resting height, and the extended height is at least 10% longer than the resting height.

[0353] The respirator can be extended from its resting height to its extended height, recover to its resting height, and the extended height is at least 30% longer than the resting height.

[0354] The respirator can be extended from its resting height to its extended height, recover to its resting height, and the extended height is at least 40% longer than the resting height.

[0355] The respirator may be constructed such that a layer of wrinkled medium includes a first series of substantially parallel and unbonded elastic filaments between first and second nonwoven porous fiber webs. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous fiber web. At least a portion of the wrinkled medium is elastically stretchable under tension.

[0356] The respirator may be constructed to fold flat along a center line.

[0357] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 3.0 mmH2O.

[0358] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 2.8 mmH2O.

[0359] The respirator may be constructed such that the pressure loss when passing through the respirator filter at an airflow rate of 85 LPM is less than 2.7 mmH2O.

[0360] The respirator may be constructed such that the quality factor exceeds 2 at an airflow rate of 85 LPM.

[0361] The respirator may be constructed such that the quality factor exceeds 2.2 at an airflow rate of 85 LPM.

[0362] The respirator may be constructed such that the quality factor exceeds 1.8 at an airflow rate of 85 LPM.

[0363] The respirator may be constructed such that the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

[0364] The respirator may be constructed such that the quality factor exceeds 2.4 at an airflow rate of 85 LPM.

[0365] The respirator may be constructed such that the quality factor exceeds 2.5 at an airflow rate of 85 LPM.

[0366] The respirator may be constructed to include a shell layer.

[0367] The respirator may be constructed to include an outer layer.

[0368] The respirator may be constructed such that the shell layer is the inner layer.

[0369] The respirator may be constructed such that the shell layer includes a mesh-like material.

[0370] The respirator may be constructed such that the shell layer includes dashed slits.

[0371] The respirator may be constructed such that the shell layer includes an elastic net.

[0372] The respirator may be constructed such that the elastic net is an extruded elastic net.

[0373] The respirator may be constructed such that the extended perimeter of the respirator is 10% longer than the stationary perimeter of the racetrack.

[0374] The respirator may be constructed to include an adsorbent layer.

[0375] The respirator may be constructed to include a cover web layer.

[0376] The respirator may be constructed to include a nose clip, foam layer, valve, or harness.

[0377] The respirator may include a strap, which may be constructed such that the strap is combined with a layer of wrinkled media to form a single article of wrinkled media.

[0378] The respirator may be constructed as a horizontal tri-fold respirator.

[0379] The respirator may be constructed such that a horizontal tri-fold respirator includes an upper panel, a lower panel, and a middle panel, with the middle panel containing a wrinkled media layer.

[0380] The respirator may be constructed such that a horizontal tri-fold respirator includes an upper panel, a lower panel, and a middle panel, with the lower panel including a wrinkled media layer.

[0381] The respirator may be constructed such that a horizontal tri-fold respirator includes an upper panel, a lower panel, and a middle panel, with the upper panel including a wrinkled media layer.

[0382] The respirator may be constructed to be a vertically folding respirator.

[0383] The respirator may be constructed to be a duckbill-type respirator.

[0384] The respirator may be constructed as a cup-shaped respirator.

[0385] The respirator may be constructed as a pleated respirator.

[0386] The respirator may be constructed to include a shell layer.

[0387] The respirator may be constructed to include an adsorbent layer.

[0388] The respirator may be constructed such that the extended perimeter of the respirator is 10% longer than the stationary perimeter of the racetrack.

[0389] The respirator may be constructed such that the extended perimeter of the respirator is 20% longer than the stationary perimeter of the racetrack.

[0390] The respirator may be constructed such that the extended perimeter of the respirator is 30% longer than the stationary perimeter of the racetrack.

[0391] The respirator may be constructed such that the extended perimeter of the respirator is 40% longer than the stationary perimeter of the racetrack.

[0392] The respirator may be constructed such that the extended perimeter of the respirator is 50% longer than the stationary perimeter of the racetrack.

[0393] The respirator may be constructed such that the extended perimeter of the respirator is 60% longer than the stationary perimeter of the racetrack.

[0394] The respirator may be constructed such that the extended perimeter of the respirator is 70% longer than the stationary perimeter of the racetrack.

[0395] The respirator may be constructed such that the extended perimeter of the respirator is 80% longer than the stationary perimeter of the racetrack.

[0396] The respirator may be constructed such that the extended perimeter of the respirator is 90% longer than the stationary perimeter of the racetrack.

[0397] The respirator may be constructed such that the extended perimeter of the respirator is 100% longer than the stationary perimeter of the racetrack.

[0398] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane.

[0399] The respirator may be constructed such that one of the first and second nonwoven layers contains a fibrous nonwoven material.

Claims

1. A horizontally flat, foldable respirator having a layer of wrinkled media, The wrinkled medium has a first series of substantially parallel and unbonded elastic filaments between a first nonwoven porous web and a second nonwoven porous web. The first nonwoven porous web is directly bonded to the second nonwoven porous web, At least a portion of the wrinkled medium is elastically stretchable under tension. Horizontal, flat, foldable respirator.

2. An upper panel configured to seal around the user's nose, A lower panel configured to seal around the user's chin, It has a central panel and, The central panel has an upper edge and a lower edge, the central panel is sealed to the upper panel along the upper edge, and the central panel is sealed to the lower panel along the lower edge. The respirator according to claim 1.

3. The respirator according to claim 1 or 2, wherein the respirator can be extended from a stationary height to an extended height and returned to the stationary height, and the extended height is at least 10% longer than the stationary height.

4. The pressure loss when air passes through the respirator filter at an airflow rate of 85 LPM is 6 mmH ２ A respirator according to any one of claims 1 to 3, wherein the value is less than 0.

5. A respirator according to any one of claims 1 to 4, wherein the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

6. The respirator according to any one of claims 2 to 5, wherein the central panel includes a layer of the wrinkled medium.

7. The respirator according to any one of claims 2 to 6, wherein two of the upper panel, the lower panel, and the central panel include the layer of the wrinkled medium.

8. The respirator according to any one of claims 2 to 7, wherein one of the upper panel, the lower panel, and the central panel includes a wrinkled nonwoven material and a nonwoven material without wrinkles.

9. Furthermore, the respirator according to any one of claims 2 to 8, comprising a shell layer containing an elastic material.

10. The respirator according to any one of claims 1 to 9, wherein the extended race track circumference of the respirator is 10% longer than the stationary race track circumference.

11. Furthermore, the respirator according to any one of claims 1 to 10, comprising a hardened layer.

12. The respirator according to any one of claims 2 to 11, further comprising a strap, the strap being combined with either the upper, lower, or central panel to form a single article of a wrinkled medium.

13. A cup-shaped respirator having a layer of wrinkled media, The wrinkled medium has a first series of substantially parallel and unbonded elastic filaments between a first nonwoven porous web and a second nonwoven porous web. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous web, At least a portion of the wrinkled medium is elastically stretchable under tension. Cup-shaped respirator.

14. Furthermore, the respirator according to claim 13, comprising a formed portion having a curve in multiple directions in the first state.

15. The respirator according to any one of claims 13 to 14, wherein the respirator can be extended from a resting height to an extended height and returned to a resting height, and the extended height is at least 10% longer than the resting height.

16. The pressure loss when air passes through the respirator filter at an airflow rate of 85 LPM is 3.0 mmH ２ A respirator according to any one of claims 13 to 15, wherein the value is less than 0.

17. A respirator according to any one of claims 13 to 16, wherein the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

18. The respirator according to any one of claims 13 to 17, further comprising a shell layer.

19. A respirator according to any one of claims 13 to 18, having elasticity so that the curvature recovers after a force is applied to the curvature.

20. The respirator according to any one of claims 13 to 19, wherein the extended race track circumference of the respirator is 10% longer than the stationary race track circumference.

21. A vertically folding respirator having a layer of wrinkled media, The wrinkled medium has a first series of substantially parallel and unbonded elastic filaments between a first nonwoven porous fiber web and a second nonwoven porous fiber web. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous fiber web, At least a portion of the wrinkled medium is elastically stretchable under tension. Vertical folding respirator.

22. The respirator according to claim 21, wherein the respirator can be extended from a resting length to an extended length and can be restored to a resting length, and the extended length is 10% longer than the resting length.

23. The pressure loss when passing through the respirator filter at an airflow rate of 85 LLPM is 3.0 mmH ２ A respirator according to any one of claims 21 to 22, wherein the value is less than 0.

24. A respirator according to any one of claims 21 to 23, wherein the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

25. The respirator according to any one of claims 21 to 24, wherein the extended race track circumference of the respirator is 10% longer than the stationary race track circumference.

26. A duckbill-type respirator having a layer of wrinkled media, The wrinkled medium has a first series of substantially parallel and unbonded elastic filaments between a first nonwoven porous fiber web and a second nonwoven porous fiber web. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous fiber web, At least a portion of the wrinkled medium is elastically stretchable under tension. Duckbill-type respirator.

27. The respirator according to claim 26, wherein the respirator is configured to fold flat along a center line and further comprises a first generally trapezoidal portion configured to contact the wearer's nose and a second generally trapezoidal portion configured to contact the wearer's chin, and one of the first generally trapezoidal portion and the second generally trapezoidal portion includes a layer of the wrinkled medium.

28. The respirator according to claim 26 or 27, wherein the respirator can be extended from a resting length to an extended length and can be restored to a resting length, and the extended length is 10% longer than the resting length.

29. The pressure loss when air passes through the respirator filter at an airflow rate of 85 LPM is 3.0 mmH ２ A respirator according to any one of claims 26 to 28, wherein the value is less than 0.

30. A respirator according to any one of claims 26 to 29, wherein the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

31. The respirator according to any one of claims 26 to 30, wherein the extended race track circumference of the respirator is 10% longer than the stationary race track circumference.

32. A pleated respirator having a layer of wrinkled media, The wrinkled medium has a first series of substantially parallel and unbonded elastic filaments between a first nonwoven porous fiber web and a second nonwoven porous fiber web. The first nonwoven porous fiber web is directly bonded to the second nonwoven porous fiber web, At least a portion of the wrinkled medium is elastically stretchable under tension. Pleated respirator.

33. Furthermore, the mask body comprises a dividing line extending horizontally, a vertical axis, a first welding pattern and a second welding pattern, a third welding pattern and a fourth welding pattern, The first welding pattern and the second welding pattern are arranged on each side of the vertical axis above the dividing line, and not crossing the dividing line. The third welding pattern and the fourth welding pattern are arranged on each side of the vertical axis below the dividing line, and not crossing the dividing line, The respirator according to claim 32, wherein each of the first welding pattern, the second welding pattern, the third welding pattern, and the fourth welding pattern is a two-dimensional closed pattern.

34. The respirator according to any one of claims 32 to 33, wherein the respirator can be extended from a resting length to an extended length and can be restored to a resting length, and the extended length is 10% longer than the resting length.

35. The pressure loss when air passes through the respirator filter at an airflow rate of 85 LPM is 3.0 mmH ２ A respirator according to any one of claims 32 to 34, wherein the value is less than 0.

36. A method for manufacturing a respirator, Acquiring items in a wrinkled state, Forming a laminate of media layers, wherein the wrinkled media article is a wrinkled layer within the laminate of media layers. To seal the laminate of the media layer, When sealed, the laminate of the media layer has a stationary racetrack circumference and can be elastically stretched to an extended racetrack circumference, the extended racetrack circumference being 10% larger than the racetrack circumference in the stationary state. method.

37. The method according to claim 36, wherein sealing includes welding, spot welding, joining, spot joining, or forming a seam.

38. The method according to any one of claims 36 to 37, wherein the respirator is a horizontal tri-fold respirator, a vertical folding respirator, a cup-shaped respirator, a pleated respirator, or a duckbill-shaped respirator.

39. The pressure loss when air passes through the respirator filter at an airflow rate of 85 LLPM is 3.0 mmH ２ The method according to any one of claims 36 to 38, wherein the result is less than 0.

40. The method according to any one of claims 36 to 39, wherein the quality factor exceeds 1.6 at an airflow rate of 85 LPM.

Images