WO2024214054A1

WO2024214054A1 - Respiratory protection devices and methods of manufacturing the same

Info

Publication number: WO2024214054A1
Application number: PCT/IB2024/053597
Authority: WO
Inventors: Wenli Wang; Nathan E. Schultz; Caroline M. Ylitalo; John M. Sebastian; Seth M. Kirk; Daniel J. Zillig; Anne C.F. Gold; Silvia G.B. Guttmann
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2023-04-13
Filing date: 2024-04-12
Publication date: 2024-10-17
Anticipated expiration: 2025-10-13
Also published as: CN121038861A

Abstract

Described herein are respirators that include a layer of wrinkled media. The wrinkled media includes a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous web. The first non-woven porous web is directly bonded to the second non-woven porous web. At least one portion of the wrinkled media is resiliently extensible under tension.

Description

RESPIRATORY PROTECTION DEVICES AND METHODS OF MANUFACTURING THE SAME TECHNICAL FIELD [0001] Respiratory devices designed with wrinkled expandable filter media that enable elasticity and low pressure drops, which reduce breathing resistance and provide enhanced comfort and fit to the wearer. Respiratory devices designed with wrinkled expandable filter media that enable elasticity, low pressure drops and high particulate loading capacity, which reduce breathing resistance and provide enhanced comfort and fit to the wearer. SUMMARY [0002] There is a desire to improve comfort and performance of respiratory protection devices. [0003] Described herein are respirators that include a layer of wrinkled media. The wrinkled media includes a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous web. The first non-woven porous web is directly bonded to the second non-woven porous web. At least one portion of the wrinkled media is resiliently extensible under tension. [0004] The above summary is not intended to describe each embodiment. The details of one or more embodiments of the invention are also set forth in the description below. Other features, objects, and advantages will be apparent from the description and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 is a schematic representation showing shirred filter media that may be useful in embodiments herein. [0006] FIG.2 is a schematic representation of a cross section of the shirred filter media, showing its construction. [0007] FIG. 3 is a schematic representation of making a shirred filter media according to one embodiment of the present disclosure. [0008] FIGS.4A-4G illustrate a trifold respirator in accordance with embodiments herein. [0009] FIGS.5A-1 to 5E-2 illustrate cup-style respirators in accordance with embodiments herein. [0010] FIGS.6A-6C illustrate respirator styles that may benefit from embodiments herein. [0011] FIG.7 illustrates a schematic of a face of a user that may benefit from embodiments herein. [0012] FIG. 8 illustrates a method of making a respiratory protection device in accordance with embodiments herein. [0013] It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the disclosure. The schematic figures may not be drawn to scale. DETAILED DESCRIPTION [0014] As used herein, the terms “a”, “an”, and “the” are used interchangeably and mean one or more; and “and/or” is used to indicate one or both stated cases may occur, for example A and/or B includes, (A and B) and (A or B). [0015] Also herein, recitation of ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.). [0016] Also herein, recitation of “at least one” includes all numbers of one and greater (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, “comprises at least one of” A, B, and C refers to element A by itself, element B by itself, element C by itself, A and B, A and C, B and C, and a combination of all three. [0018] As used herein, the term “respirator” refers to a close-fitting facial covering device that filters inhaled and exhaled air of particles and droplets. Respirators, as described herein, may be designed to seal to a user’s face along an uninterrupted seal perimeter (often referred to as a “racetrack”). Such features distinguish respirators from cloth face masks, surgical masks, etc. In some embodiments, respirators herein contain fibers that are electrically charged to attract particles, increasing loading capacity. [0019] Disposable respirators are used in a variety of environments and industries. Ubiquitous at the height of the COVID-19 pandemic, disposable respirators come in a variety of makes and models. The COVID-19 pandemic saw a lot of innovation in this area to increase surface area of a respirator, in order to have a lower pressure drop, which translates to decreased breathing resistance leading to improved comfort for users. Amazon PerfectFit and Airgami® are two of many different concepts that resulted. However, there is still a need to further increase surface area, and decreased breathing resistance leading to improved comfort, while maintaining high loading rates of particulates. Additionally, it is also desired to increase a stretch factor of a respirator, which can allow for a single respirator design to accommodate a wider range of facial shapes. A flexible and stretchable filter allows designers to create respirators that accommodate facial movements of the wearer. [0020] There are many different configurations of disposable respirators in the market. The vast majority of them however have fixed shapes and dimensions that do not stretch to accommodate the wearers’ facial movement such as yawning, laughing or talking as well as desired. In some cases the respirator may slide or move with wearer’s facial movement that lead to poor fit and leaks or even scratches to wear’s face. A few respirator designs that do offer stretch flexibility either involve bulky plastic structure that maybe heavy or have limited stretchability with extra filter media. Described in embodiments herein are flexible and expandable respirator designs able to accommodate a larger range of face sizes. [0021] Lowering pressure drop across the respirator’s filter media decreases breathing resistance leading to improved comfort. The two most common practice to reduce pressure drop are to use larger area flat sheets and to use pleat packs. The first leads to bulkier design and the latter tends to be rigid and boxy for respirators. The use of wrinkled media in respirators, as described in embodiments herein, provides both a larger surface area than flat sheet media while maintaining more compact or lower profile than pleat pack with good conformity. [0022] Embodiments herein incorporate a type of functional media laminate (referred to as Wrinkled Media hereafter) with optional reticulated support in the overall respirator designs. Wrinkled Media is described in greater detail with respect to function in the Examples section of US Provisional Patent Application 63/434365, Filed December 21, 2022, which is incorporated by reference herein. [0023] Wrinkled media differs from flat sheet and pleated pack commonly used in respirators in several ways. It provides larger surface area with compact profile through the wrinkled surface. The elastic construction enables stretching capabilities, potentially allowing for better fitting or more comfortable and conformable respirator designs. And some embodiments herein include a reticulated open mesh (referred to as “skip slit” hereafter (For example, as described in PCT Publication WO 2018/090280 A1) shell or an elastic netting, which provides support to wrinkled media with resilience to stretch. [0024] Respirators in embodiments herein, in addition to having a unique appearance, exhibits lower breathing resistance and stretchy functionality while maintaining good fit. With proper respirator design such as multi-panel or support shell components, respirators described herein exhibit low pressure drop with good stretchability. In some embodiments, the respirator can also be folded to flat. [0025] Embodiments herein contrast with previous work that either used plastic structures to support extra filter media to give it stretchability (but made them bulky and not foldable) or using corrugated media to help decrease breathing resistance (but not stretchable or foldable). [0026] Shown in FIG. 1 is top view of an exemplary embodiment of a shirred filter media of the present disclosure. Shirred filter media 10 comprises a plurality of elastic filaments that are spaced apart. The plurality of elastic filaments are sandwiched between two non-woven porous fibrous webs. During fabrication of the shirred filter media (herein referred to as “wrinkled media”), the elastic filaments are pulled under tension, such that when the tension is released, the non-woven porous fibrous webs become puckered. Shown in Fig.2 is a side view of filter media 20 showing a first non-woven porous fibrous web 24 and a second non-woven porous fibrous web 26, with elastic filament 22 positioned therebetween. FIG.2 shows that first non-woven porous fibrous web 24 is in direct contact with second non-woven porous fibrous web 26. Based on the resulting articles, it is believed that when adhesive is used, the adhesive bonds the two non-woven porous fibrous webs together with the filaments therebetween. It is assumed that the bonding of the first and second non- woven porous fibrous webs is discontinuous and that the non-woven porous fibrous web(s) may not be bonded (for example, adhesively bonded) to the filament along the full length of the filament. Material Tables – Nonwoven Media [0027] Table 1 lists the nonwoven webs used in making shirred media as described in US Provisional Patent Application 63/434365, Filed December 21, 2022 and Table 2 lists their initial pressure drop (dP) and penetration in NaCl and DOP tests.

Table 1. Nonwoven webs used in making shirred media and respirators Media Media Material Source Properties ID F1 Polypropylene A non-woven melt blown fibrous Having a basis weight of web having fibers with a charging 16 gsm, a thickness of additive package as described in US 0.010 in (0.26 mm), 6.6% 10,724,171 (Schultz et al.), which solidity, and an effective can be prepared per Process A and fiber diameter of 6.5 Charging Method 3 as disclosed in micrometers. US 10,724,171. F2 Polypropylene A non-woven melt blown fibrous Having a basis weight of web having fibers with a charging 61 gsm, a thickness of additive package as described in US 0.035 in (0.88 mm), and 10,724,171, which can be prepared an effective fiber diameter per Process A and Charging Method of 7.5 micrometers. 3 as disclosed in US 10,724,171. F4 Polypropylene A non-woven melt blown fibrous Having a basis weight of web having fibers with a charging 18 gsm, a thickness of additive package as described in US 0.008 in (0.19 mm), 7.7% 10,724,171, which can be prepared solidity, and an effective per Process A and Charging Method fiber diameter of 7.0 3 as disclosed in US 10,724,171. micrometers. F5 Polypropylene A non-woven fibrillated film media Having a basis weight of prepared per procedures disclosed in approximately 150 gsm, US 3,998,916 and US 4,178,157 thickness of 3.9 mm, and a rectangular cross section of approximately 10 µm x 40 µm. F6 Polypropylene A non-woven fibrillated film media Having a basis weight of prepared per procedures disclosed in approximately 90 gsm, US 3,998,916 and US 4,178,157 thickness of 1.8 mm, and a rectangular cross section of approximately 10 µm x 40 µm. F9 Polypropylene A spunbond non-woven media Having a basis weight of prepared as described below 65 gsm, a thickness of 0.038 in (0.97 mm), and an effective fiber diameter of approximately 23 micrometers F10 Polypropylene A high loft Spunbond non-woven Having a basis weight of media, prepared as described below 45 gsm, a thickness of 0.034 in (0.86 mm), and an effective fiber diameter of approximately 28 micrometers Table 2. Flat nonwoven webs’ initial dP and penetration in NaCl and DOP tests S^{amples of Flat Nonwoven Media webs} NaCl test at 13.9 cm/s DOP test at 13.9 cm/s Media Media Initial dP Initial QF Initial dP Initial QF ID. (mmH2O) Pen (mmH2O) Pen F1 BMF 6 um 1.7 -- -- -- -- -- F2 BMF 7.5 um 6.8 0.17% 0.94 -- -- -- F4 BMF 7 um 3.1 12.8% 0.66 -- -- -- F5 Fibrillated film150 2.6 3.7% 1.3 -- -- -- F6 Fibrillated film 90 1.3 17% 1.4 -- -- -- F9 HL 85 -- -- -- 0.65 50% 1.07 F10 UHL-T1 -- -- -- 0.23 63% 2.01 Elastic filaments [0028] The elastic filaments of the present application comprise a polymer and are elastic in nature, meaning that the filament is capable of recovering or at least partially recovering in length following stretching. The filament roll is available under the trade designation “100% Lycra Spandex 235 Multifil”, DTEX Type 737, 210 denier from Invista Company, Wichita, Kansas. Exemplary types of polymeric materials that may be used for filaments of the present application include: natural rubber, synthetic rubber, polyether-polyurethanes, polyamides, polyisoprenes, copolymers of isoprene and neoprene, polymers of 2-chloro-1, 3-butadiene, polyether-polyurea copolymer (e.g., Lycra), polyurethane (e.g., spandex). Other examples include Kraton™ copolymers. Those are elastomeric tri-block polymers comprising high Tg end blocks made of polystyrene and low Tg center block made of one or more isoprene, butadiene, and the like. [0029] In one embodiment, the filaments have a diameter of at least 1, 5, 10, or even 20 micrometers and at most 25, 50, 100 micrometers. In one embodiment, the filaments have a denier of at least 100, 150, 175, 200, 210, 220, 250, or even 500. In one embodiment, the filaments have a denier of at most 1200, 900, 800, 700, 600, 500, 400, 350, 300, 250, or even 225 denier. [0030] The effective fiber diameter can be estimated by using the measured pressure drop across a filter of known material according to the method set forth in C. N. Davies, Air Filtration (Academic, London, 1973). Non-woven porous fibrous web [0031] The plurality of elastic filaments is positioned between two non-woven porous fibrous webs, herein referred to as a non-woven web. The nonwoven webs of the present disclosure can be made by wet laid, carded, air laid, spunlaced, spunbonding, spunmelt, or melt-blowing techniques or combinations thereof. The nonwoven webs herein may also be formed of fibrillated film fibers. The nonwoven webs herein may also be formed of fibrillated film (for example that described in US Patent RE32171, published on June 3, 1986). [0032] In some embodiments, a nonwoven web may undergo a relofting step after formation to increase loftiness. The nonwoven webs may also include or be composed of a scrim or netting. The nonwoven webs may comprise nanofibers produce by electrospinning processes and the like. Spunbonded fibers are formed by extruding molten thermoplastic polymer as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded fibers being rapidly reduced. Meltblown fibers are typically formed by extruding the molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into a high velocity, usually heated gas (e.g., air) stream which attenuates the filaments of molten thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to from a web of randomly dispersed meltblown fibers. Any of the non-woven webs may be made from a single type of fiber or two or more fibers that differ in the type of thermoplastic polymer and/or thickness. [0033] Suitable thermoplastic polymeric materials include, but are not limited to, polyolefins (such as polypropylene, or polyethylene), poly(isoprenes), poly(butadienes), fluorinated polymers, chlorinated polymers, polyamides, polyimides, polyethers, poly(ether sulfones), poly(sulfones), poly(vinyl acetates), polyesters such as poly(lactic acid), copolymers of vinyl acetate, such as poly(ethylene) –co-poly(vinyl alcohol), poly(phosphazenes), poly(vinyl esters), poly(vinyl ethers), poly(vinyl alcohols), and poly(carbonates). [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, alpha olefin copolymers (such as copolymers of ethylene or propylene with 1-butene, 1-hexene, 1-octene, and 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(pyromellitimide). [0036] Suitable poly(ether sulfones) include, but are not limited to, poly(diphenylether sulfone) and poly(diphenylsulfone-co-diphenylene oxide sulfone). [0037] Suitable copolymers of vinyl acetate include, but are not limited to, poly(ethylene-co-vinyl acetate) and such copolymers in which at least some of the acetate groups have been hydrolyzed to afford various poly(vinyl alcohols). [0038] The fibers selected for the non-woven web depend upon the kind of particulate to be filtered. Particularly useful fibers include webs of melt-blown fibers, such as those disclosed in Wente, Van A., "Superfine Thermoplastic Fibers", 48 Industrial Engineering Chemistry, 1342 et seq (1956). Webs of meltblown fibers provide especially good filtration layers when used in a persistent electrically charged form (see U.S. Pat. No.4,215,682 to Kubik et al). Preferably, these melt-blown fibers are microfibers having an effective diameter of at least 4, 6, 8 or even 10 micrometers and at most 12, 14, 16 or even 20 micrometers. Other particularly useful filtration fibers are electrically- charged-fibrillated-film-fibers as disclosed in U.S. Pat. No. RE 31,285 to Van Turnhout. Rosin wool fibrous webs and webs of glass fibers are also useful, as are solution spun, or electrostatically sprayed fibers, especially in microfiber form. [0039] The non-woven webs are porous, meaning that the outside surface of one side of the non- woven web is in fluid communication with the outside surface on the opposing side of the same non- woven web. This ensures flow of vaporous fluids, air, or liquids through the non-woven web. The non-woven webs are coextensive meaning that the web is a complete, continuous layer of non-woven material with no rips or tears. [0040] In one embodiment, at least one of the non-woven webs of the present disclosure comprises electret fibers. Electrets are a dielectric material that possess a quasi-permanent electric charge or dipole polarization. Electrets typically are improved by incorporating a charging additive into a polymeric material and then inducing a charge onto the polymeric materials using a corona treatment, a tribocharging treatment, a hydrocharging treatment, or combinations thereof. In one embodiment, the electret fibers are monocomponent fibers. In another embodiment, the electret fibers are bicomponent fibers, such as sheath-core, side-by-side, etc. In one embodiment, the electret fibers are sheath-core fibers comprising a core having a coextensive sheath layer disposed thereon. In one embodiment, the core comprises an electrostatic charge enhancing additive. In one embodiment, the sheath comprises an electrostatic charge enhancing additive. In one embodiment, the electret fibers are side-by-side, wherein the fiber comprises two components lying next to each other along the length of the fiber. In one embodiment, the electret fibers are so called “islands-in-the-sea” extrudates, wherein multiple fiber cores (i.e., more than 1, 2, 4, or even 6 cores) are distributed within a polymer matrix, which also forms the sheath. [0041] Many charge enhancing additives for making electret-containing fiber webs are known in the art. Exemplary electrostatic charge enhancing additives may include pigments, light stabilizers, primary and secondary antioxidants, metal deactivators, hindered amines, hindered phenols, metal salts, phosphite triesters, phosphoric acid salts, and combinations thereof. Preferably, the charge enhancing additive is a solid at ambient conditions to prevent migration within the resin and does not decompose at moderate temperatures. In one embodiment, the charge enhancing additive is a solid at temperatures of at least 25, 30, 40, 50, 60, 80 or even 100°C. In one embodiment, the charge enhancing additive does not decompose, for example, there is no significant weight loss (i.e., less than 5, 1, or even 0.1 wt %) when measured under nitrogen by thermogravometric analysis using a ramp rate of 10 °C/min to heat up to 235°C. [0042] Particularly preferred change enhancing additives include hindered amine-based additives, triazine-based additives, and hindered phenol-based additives. [0043] Specific examples of the hindered amine-based or triazine-based additives include (poly[[6- (l,l,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 under the trade designation “CHIMASSORB 944” from BASF, Ludwigshafen, Germany; dimethyl succinate-1-(2- hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, available under the trade designation “TINUVIN 622” from BASF; di-tert-butyl-4-hydroxybenzyl)-2-n-butyl malonate bis(1,2,2,6,6-pentamethyl-4-piperidyl available under the trade designation “TINUVIN 144” from BASF; a 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 under the trade designation “CHIMASSORB 2020” from BASF; 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-((hexyl)oxy)- phenol, available under the trade designation “TINUVIN 1577” from BASF; N-substituted amino aromatic compounds, particularly tri-amino substituted compounds, such as 2,4,6-trianilino-p- (carbo-2'-ethylhexyl-l'-oxy)-l,3,5-triazine, available under the trade designation “UVINUL T-150” from BASF; and 2,4,6-tris-(octadecylamino)triazine, also known as tristearyl melamine ("TSM"). [0044] Hindered phenol-based additives having a hydroxyl group as the terminal functional group. he hindered phenol-based additives are not particularly limited, and specific examples include pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010, manufactured by BASF), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 1076, manufactured by BASF), tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate (Irganox 3114, manufactured by BASF), 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, manufactured by Sumitomo Chemical Co., Ltd.), and the like. [0045] Additional thermally stable organic triazine compounds or oligomers, which compounds or oligomers contain at least one nitrogen atom in addition to those in the triazine ring, are disclosed in U.S. Patent Nos 6,268,495, 5,976,208, 5,968,635, 5,919,847, and 5,908,598 to Rousseau et al. [0046] Further examples of charge-enhancing additives are provided in U. S. Publ. No. 2011/0137082 (Li et al.). U. S. Pat. Nos. 8613795 (Li et al.), 7,390,351 (Leir et al.), U. S. Pat. No. 5,057,710 (Nishiura et al.), and U. S. Pat. Nos.4,652,282 and 4,789,504, both to Susumu et al., and U. S. Pat. No.8,790,449 B2 (Li et al.). [0047] The charge-enhancing additive(s) can be added in any suitable amount. The charge- enhancing additives of this disclosure may be effective even in relatively small quantities. Typically, the charge-enhancing additive is present in a thermoplastic resin and charge-enhancing additive blend in amounts of up to about 10 % by weight, more typically in the range of 0.02 to 5 % by weight based upon the total weight of the blend. In some embodiments, the charge-enhancing additive is present in an amount ranging from 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. Membrane and Non-woven Porous Web with Sorbent [0048] Alternatively or additionally, porous membrane may be used in place of, and / or combined with the non-woven fibrous web. The membrane may be a polyolefin porous membrane, a polyacrylonitrile porous membrane, a polycarbonate porous membrane, a polyester porous membrane, a cellulose ester porous membrane, a polyamide porous membrane, a polyethersulfone porous membrane, a polysulfone porous membrane, , a polyacrylonitrile nanofiber membrane, a PVDF nanofiber membrane, a cellulose ester nanofiber membrane, a polyvinyl acetate or alcohol nanofiber membrane, a nylon membrane, or a polyvinyl butyral nanofiber membrane. [0049] The membrane can be made by, for example, TIPS (thermally induced phase separation) process, SIPS (solvent induced phase separation) process, VIPS (vapor induced phase separation) process, stretching process, track-etching, or electrospinning (e.g., PAN fiber membranes). [0050] A wrinkled membrane may be wrinkled, for example, using the techniques described herein above with respect to FIGS. 1-2. In some embodiments, the plurality of elastic filaments are positioned between a membrane layer and one or more non-woven porous webs. However, it is expressly contemplated that, in some embodiments, the plurality of elastic filaments are positioned between a first membrane layer and a second membrane layer, which may have the same or different composition. The membrane layer may include membrane and one or more non-woven webs stacked or laminated or bonded. [0051] Alternatively, or additional, non-woven porous web may comprise of a sorbent material. The sorbent particles may be disposed on the surface of non-woven web or throughout the depth of non- woven web. One example of the sorbent material is activated carbon either untreated or chemically treated. Other sorbent materials such as polymeric sorbent may be used as well. Method of Making [0052] In one embodiment, the wrinkled filter media of the present application can be made by stretching a first series comprising a plurality of elastic filaments. The filaments are not generally bonded to one another (for example, the filaments of the present disclosure are not a scrim). The plurality of elastic filaments in the first series are held (for example using a spacer) such that each of the filaments is substantially parallel to one another and are spaced a given distance apart. Generally, the substantially parallel filaments should not touch the nearest neighbor filament in the working portion of the finished good. In one embodiment, the elastic filaments are held with a spacing of at least 2, 4, 5, or even 6 filaments per inch. In one embodiment, the elastic filaments are held with a spacing of at most 8, 10, 12, 15, 20, or even 25 filaments per inch. Generally, the spacing of the filaments is selected to achieve the desired shirring of the non-woven web without causing a large change in pressure. [0053] Shown in FIG. 3 is exemplary configuration of a first series of filaments 32, wherein the filaments are tied at either end and combs 35 and 37 are used at both ends to hold the filaments substantially parallel. The first series of filaments are placed between first non-woven porous fibrous web 34 and second non-woven porous fibrous web 36. Nonwoven web 36 is placed below the stretched plurality of parallel filaments with the adhesive side contacting the filaments. The second adhesive-sprayed web 34 is placed above the stretched plurality of parallel filaments with the adhesive side contacting the filaments. Then, a cardboard roller compresses the laminate gently to remove any air pockets so that the two nonwoven webs were adhered together with the filaments positioned in between the two webs. [0054] The manual hold of the stretched plurality of parallel filaments is then released, and the filaments are allowed to relax causing the laminated media (web-adhesive-filament-adhesive-web) to pucker. Additional details of how wrinkled media can be made can be found in US Provisional Patent Application 63/434365, filed December 21, specifically in paragraphs [0027-0037], which are incorporated herein by reference. [0055] The filaments can be stretched to any desired length. The % stretch as 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 converted to a percent. In one embodiment, the elastic filaments are stretched to greater than 50, 75, 100, 150, 200, or even 250%. The filaments can be stretched more than 250% so long as the filaments do not go beyond the elastic limit to deformation or break during the manufacturing of the wrinkled media disclosed herein. [0056] The first and second non-woven webs are positioned on either side of the stretched filaments. The first and second non-woven webs may be the same or different. The non-woven webs are selected based on the desired performance properties. The non-woven webs selected may be different in terms of composition, basis weight, thickness, porosity, etc. [0057] The first and second non-woven webs are bonded directly together such that the first non- woven web contacts the second non-woven web, optionally with the use of an adhesive as exemplified below. In one embodiment, an adhesive is used to directly bond (or adhere) the first and second non-woven webs together. Such adhesives can include a pressure sensitive adhesive or a hot melt adhesive. Pressure sensitive adhesives are known in the art and are generally adhesives that can adhere based on room temperature conditions when pressure (e.g., finger pressure) is applied. Exemplary pressure sensitive adhesives include: a natural latex or synthetic polymer such as a (meth)acrylate. A commercially available pressure sensitive adhesive includes a spray adhesive available under the trade designation “3M Super 77 Multipurpose Adhesive” by 3M Company, Maplewood, MN, USA. Hot melt adhesives are those adhesives that are thermoplastic polymers which are heated above their softening point and when applied in their softened state to a surface, penetrate the surface and solidify ensuring cohesion. Exemplary hot melt adhesives include: Bostik HM-9041 available from Bostik inc., Wauwatosa, WI, and Tailored HM011BA available from Tailored Chemical Products Inc., Hickory, NC. In the embodiments of the present application when an adhesive is applied, the weight of adhesive used per unit area is less than the weight per unit area of the non-woven web. In one embodiment, the weight per unit area of the adhesive is less than 0.5, 0.4, 0.3, 0.2, or even 0.1 % of the weight per unit area of the non-woven porous fibrous webs in the article. Ideally, the adhesive should not interfere with the performance of the article and should be collapsible, meaning that the adhesive can maintain cohesiveness (or keep the two layers of non- woven webs bonded) upon the relaxing of the stretched filaments during manufacture. In one embodiment, the adhesive is at least 1, 2, 4, 5, or even 6 gsm (grams per square meter) in the wrinkled article. In one embodiment, the adhesive is at most 8, 10, 15, 20, 40, 60, 80 or even 100 gsm in the wrinkled article. In another embodiment, the first and second non-woven webs are welded directly together such that the first non-woven porous fibrous web is in intimate contact with the second non- woven porous fibrous web. Such welding techniques are known in the art and include thermal bonding or ultrasonic welding. [0058] After bonding (or adhering) the first and second non-woven porous fibrous webs together, the tension is released on the stretched elastic filaments and the resulting article puckers or becomes shirred as represented schematically in FIG.1. Typically, after the tension is released on the stretched elastic filaments, it could take upwards of hours or days for the shirred article to achieve its final puckered state as an equilibrium in the construction is reached. In one embodiment, the heat can be used to more quickly achieve this stable state. [0059] In addition to the first and second non-woven webs, additional layers (e.g., a third layer) maybe added to the shirred article to provide additional functionality. The third layer may be added before release of the tension on the filaments, such that the third layer is also puckered or shirred. In another embodiment, the third layer is added after release of the tension on the filaments, such that the third layer is a flat layer bonded to the puckered or shirred article. Exemplary third layers include cover webs, which is a layer used to protect the underlying article from abrasion, soiling, etc. The third layer may also provide cosmetic and visual function. [0060] In another embodiment, in addition to the first series of elastic filaments, a second series of filaments can also be used, wherein the first and second series of elastic filaments are positioned non- parallel to each other (for example at least 45 degrees or at least 90 degrees apart). The shirred article is made as described above, except that both series of elastic filaments are placed between the two non-woven webs. When tension is released on both series of filaments, the resulting article has a more complex puckered pattern as shown in the Example Section. [0061] In yet another embodiment, the series of elastic filaments may be stretch to different percentages, such that when the tension is released the resulting puckered material comprises areas with more puckering and areas with less puckering. [0062] The articles of the present disclosure are resiliently extensible under tension, meaning that when the puckered article is pulled in the same direction as the length of the elastic filaments, the puckered article can elongate (or flatten out) and when the tension is released, the elongated article returns to its puckered form. In one embodiment, the puckered article is elastically extensible to at least 2 or even 3 times of its relaxed length. In some embodiments, the puckered article comprises at least one portion which is resiliently extensible under a first tension, wherein a second portion of the shirred filter media is under a second tension. [0063] Because the articles of the present disclosure have a puckered (or shirred) appearance, the basis weight of the resulting article has a higher basis weight than the original flat or unwrinkled non- woven porous fibrous webs. In one embodiment, the shirred articles of the present disclosure have a basis weight of at least 10, 15, 20, 30, 40, 50, 75, or even 100 grams per square meter (gsm). In one embodiment, the shirred articles of the present disclosure have a basis weight of at most 100, 125, 150, 175, 180, 200, 225, 250, or even 300 gsm. [0064] The resulting shirred media is self-supporting meaning that an addition layer is not needed to provide support to the non-woven web/filament/non-woven web construction, optionally comprising an adhesive. Such articles can be used to filter out undesirable particles from the fluids, such as dust, molds, oily mist aerosol, cigarette smoke, pet dander, viruses, bacteria, etc. [0065] The filter media of the present disclosure described herein may have a variety of suitable air permeabilities. In one embodiment, the filter media has an air permeability of greater than or equal to 2, 5, 10, 15, 20, 25, 30, 40, 50, 75, 100, 120, 150, 170, 200, 275, 300, 350, 400 or even 450 CFM/sqft. In some embodiments, the filter media has an air permeability of less than or equal to 450, 400, 350, 325, 300, 275, 250, 225, 200, 170, 150, 120, 100, 75, 60, 50, 40, 35, 30, or even 25 CFM/sqft. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 20 CFM/sqft and less than or equal to 350 CFM/sqft, greater than or equal to 35 CFM/sqft and less than or equal to 170 CFM/sqft, or greater than or equal to 20 CFM/sqft and less than or equal to 350 CFM/sqft). Other ranges are also possible. The air permeability of a filter media may be determined in accordance with ASTM Test Standard D737 (1996). [0066] Filtration performance test results of shirred media articles are discussed in greater detail in US Provisional Patent Application 63/434365, filed December 21, specifically in the Examples, which are incorporated herein by reference. Test Methods [0067] The following test methods were used to evaluate media examples. A minimum of two samples were tested and averaged for each Example (EX) and Comparative Example (CE) unless otherwise specified. [0068] Unless otherwise noted, all initial and loading NaCl penetration and pressure drop tests for webs were run at a face velocity of 13.9 cm/sec. The listed media web performance in Tables 3 are actual measurements per Test Methods listed. [0069] The respirator samples were mounted on holders designed for specific respirator types within corresponding test chambers for testing. For example, the horizontal flat fold respirator like Aura respirator had the headbands and staples removed first, when applicable. Then the flat folds were opened up to be set on an open cylindrical holder with respirator outlet or downstream side facing up. The two sides where headbands were stapled or welded to were spread out and positioned into two grooves on the cylindrical holder. Optionally, the holder may have a dome-shaped open structure in the opening area to provide support to the respirator. With the respirator fully open and set on the holder, a slightly larger cylindrical ring was pushed onto the perimeter of the mounted respirator, so the respirator perimeter was sandwiched between the holder and ring to form a tight seal. The mounted assembly was then placed in a test chamber, which may provide further compression during the tests to ensure a good seal. [0070] In another example, the cup shaped respirator can be mounted in a holder in a similar fashion but with holder dimensions designed for the specific cup style. The holder with respirator mounted on was then positioned and aligned on a tester such as the TSI^TM Model 8130 high-speed automated filter tester (available from TSI Inc., Shoreview, Minnesota) for testing. Optionally, a larger size cup shaped respirator or a cup shaped respirator samples with perimeter extended out and with adequate mechanical resistance from deformation or collapse under air flow, may also be directly placed on top of the lower chuck of a TSI^TM Model 8130 high-speed automated filter tester (available from TSI Inc., Shoreview, Minnesota) with its outlet or downstream side facing up. When the upper chuck came down upon testing command, the respirator perimeter was compressed and sealed under the pressure between upper and lower chucks. [0071] Other styles of respirators such as 3M VFlex® respirator or vertical flat fold respirator available under the trade designation “3M Disposable Respirator 9105 or 9010” from 3M Company, Maplewood, MN, USA may be mounted on holders specifically designed for their shapes and sizes and tested in a similar fashion. The respirator holders and test chambers can be made of various materials. Some were selected due to their transparency property for easy observation of test. The examples include plexiglass, polycarbonate, acrylic and polystyrene. NaCl Initial Tests and Quality Factor: [0072] Pressure drop and percent penetration of respirators may be determined using a challenge containing NaCl particles, delivered at a flow rate of 85 liters/min or LPM, and evaluated using a TSI™ Model 8130 high-speed automated filter tester (available from TSI Inc., Shoreview, Minnesota). An MKS pressure transducer (available from MKS Instruments, Andover, Massachusetts) may be employed to measure pressure drop (dP, mm H2O) through the filter media or filter samples. [0073] For NaCl instantaneous testing at 85 liters/min (i.e. LPM) and using 0.075 µm diameter particles, the particles may be generated from a 2% NaCl solution to provide an aerosol containing particles at an airborne concentration of about 16-23 mg/m3, and the Automated Filter Tester may be operated with both the heater and particle neutralizer on. The NaCl initial penetration and pressure drop tests last about 19 seconds. [0074] The NaCl particles are forced through a media sample that has 11.4 cm in diameter or 102 cm² opening at a rate of 85 LPM. [0075] The NaCl percent penetration is defined by the following formula: %Pen = (Concentration downstream / Concentration upstream) x100 [0076] The NaCl percent penetration and pressure drop are used to calculate a quality factor “QF” by the following formula: ^^{^ ^^ െln ^% ^^ ^^ ^^ /100^} ^{^}

[0077] A higher initial QF value indicates better initial filtration performance. Decreased QF values effectively correlate with decreased filtration performance. NaCl Loading Test: [0078] Loading tests were performed on a TSI™ Model 8130 high-speed automated filter tester (available from TSI Inc., Shoreview, Minnesota) according to the procedure set forth in the tester manual. The samples received continuous NaCl challenge at 85 LPM with the particle ionizer operating. Tested flat samples had an exposed area of 100.2 cm² with a nominal face velocity of 13.9 cm/sec for flat and wrinkled media sheets. [0079] The samples may be loaded with NaCl particles till a pre-determined amount of NaCl particles was reached or till the pressure drop reached a pre-determined threshold. The calibrated photometers may be employed at the filter inlet and outlet to measure the particle concentration and the % particle penetration through the filter. Respirator Construction and Performance [0080] FIGS. 4A-4E illustrate a horizontal flat-fold respirator in accordance with embodiments herein. FIGS. 4A-4E illustrate a respirator formed of three panels – a top panel that engages a wearer’s nose, a bottom panel that engages a wearer’s chin, and a central panel that extends between the top panel and the bottom panel. The top panel is joined to the central panel along a perimeter of the central panel, through either a fold-line, seam, weld or bond, said fold-line, seam, weld or bond of said first panel being substantially coextensive with an edge of said central panel. The bottom panel has an edge defined by a perimeter joined to the central panel through a fold-line, seam, weld or bond, said fold-line, seam, weld or bond of said second panel being substantially coextensive with an edge of said central panel. Additionally, while welds and bonds are discussed, it is expressly contemplated that these may not be complete – e.g. a dashed or point weld or bond may be used in embodiments herein, which would allow for stretching along the sealed edge. Respirators of this type may be capable of being folded flat for storage and, during use, but are capable of forming a cup- shaped air chamber over the nose and mouth of the wearer. [0081] This design of respirator may commonly be referred to as a trifold respirator, a three-panel respirator, a flat-fold respirator, or a horizontal flat-fold respirator, all of which may be used interchangeably. Construction of horizontal flat-fold respirators is described in greater detail in U.S. Patent 6,123,077, issued on September 26, 2000. Horizontal flat-fold respirators with antifog mechanisms are described in U.S. Patent 9,770,611, issued on September 27, 2017. Horizontal flat- fold respirators may also have unfolding features, as described in U.S. Patent Publication 2008/0271740, published November 6, 2008. Horizontal flat-fold respirators may also include concave areas, as described in U.S. Patent Publication 2008/027139, published November 6, 2008, which may increase fit or comfort. [0082] FIG. 4A and 4B illustrate a horizontal flat-fold respirator 100 with a center panel 110 composed of wrinkled media while top panel 120 and bottom panel 130 are composed of flat nonwoven material. However, it is expressly contemplated that either, or both, of panels 120, 130 may also be composed of wrinkled media. For example, a bottom panel 130 composed of wrinkled media would offer additional stretch of panel 130 as illustrated in FIGS. 4C-4E – which may allow for a wider variety of users that can safely wear respirator 100. [0083] FIGS.4C-4E illustrate the functional benefits of a respirator 140 designed like respirator 100 with wrinkled media as the center panel, but also having a wrinkled media as the bottom panel. In FIG. 4C the wrinkled media as the center panel is oriented to be generally stretchable in a nose-to- chin direction while a separate piece of wrinkled media as the bottom panel is oriented to be generally stretchable in ear-to-ear direction. The wrinkled media in bottom panel can be further stretched around the wearer’s chin area to provide better conformance. FIG. 4C illustrates an image 150 of respirator 140 on a manikin head. FIG.4D illustrates respirator 140 in a relaxed position 160, while FIGS. 4E-1 to 4E-3 illustrate respirator 140 in various stretched positions 170A-170C. The center panel had a resting height 112 (distance between the edge coupled to the bottom panel and the edge coupled to the top panel, along a line perpendicular to both edges) of 3.5” in a resting position, which increased to a stretched height 114 of 5” in a stretched position 170A. That is about 40% stretch in the center panel. In the second stretched position 170B, the stretched height 114 was purposely reduced to about 4.5” while the bottom panel was stretched out to have a hammock-like contour around wear’s chin area. The overall stretched height 124 was about 6”. That is about 30% stretch when compared to relaxed height. In another stretched position 170C, the stretched height 114 was purposely reduced to about 4.0” while the bottom panel was further stretched out and conforming to a different shape. Further stretch with both center and bottom panels to 7” in the direction of 114 was also feasible. That is about 100% stretch. [0084] FIG.4F illustrates a different respirator 180 designed with wrinkled media as the center and bottom panels and with the bottom panel oriented to be stretchable in an extended nose-to-chin direction. FIG. 4G illustrates a respirator 190 with a total of 4 panels and wrinkled media as the bottom 3 panels. [0085] A wrinkled center panel accommodates individuals with longer distances from nose to chin, and allows for better conformability, especially during facial movements while talking or laughing or yawning. In contrast, a height of a non-wrinkly nonwoven panel (e.g. the top panel) remains substantially unchanged. Similarly, having wrinkled media on a bottom panel allows for better conformability to an individual’s chin, also further increases adjustability, as seen in the transition between FIG.4E-3 (stretch height 124) and 4E-2 (relaxed height 122). [0086] However, while FIGS. 4A-4G illustrate a horizontal flat-fold respirator with either a single wrinkled media panel, as a center panel, or two wrinkled media panels as the center and bottom panels, or three bottom wrinkled media panels, it is expressly contemplated that wrinkled media may be present in a number of configurations. For example, the top and bottom panels may both be composed of wrinkled media in some embodiments. Only the top panel may be composed of wrinkled media in some embodiments. Only the bottom panel may be composed of wrinkled media in some embodiments. The top and center panels may be composed of wrinkled media in some embodiments. The center and bottom panels may be composed of wrinkled media in some embodiments. All three panels may be composed of wrinkled media in some embodiments. Any panel may have a combination of wrinkled media and non-wrinkly media in some embodiments. In some embodiments, a harness (e.g. earloops or straps to hold the respirator in place against a wearer’s face) may be composed of wrinkled media. In some embodiments, the harness and the center panel are formed of a single wrinkled media article. In some embodiments a first wrinkled media article forms the top panel and a first strap, while a second wrinkled media article forms the bottom panel and a second strap. A horizontal flat fold respirator may also include other features, including fit features such as a nose clip in the top panel to ensure a seal around a wearer’s nose, a foam portion to increase comfort and fit about a wearer’s nose, etc. In some embodiments, the top panel is composed of a material that exhibits an increased pressure drop compared to both the center and bottom panel. This may increase fog-resistance. In some embodiments the respirator may include an exhalation valve such as that described in D746,974, titled “Exhalation valve flap” and US10,905,903 titled “Respirator Having Optically Active Exhalation Valve”, both incorporated herein by reference. The valve is preferably located in the center panel but it can also be located in the top or bottom panels of the tri-fold respirator. [0087] FIGS. 5A-5E illustrate cup-style respirators in accordance with embodiments herein. Like horizontal flat-fold respirators, attempts have been made to increase the surface area of cup-style respirators and to decrease breathing resistance leading to improved comfort. Some previous attempts include adding pleated media to a cup-shaped mask design, as illustrated in Design Patent D677779 and U.S. Patent No.10,834,980 – both to Moldex. [0088] Cup-style masks 210, 220 and 230 were made with wrinkled media and welded to a 3M® respirator 8210 shell. Initial pressure drops and instantaneous penetration percentage during an NaCl challenge at 85 LPM (described herein) were measured and compared to select respirators not containing wrinkled media. The results are illustrated in Table 3 below. [0089] FIGS. 5A-1 and 5A-2 illustrate a first cup-style respirator 210. Respirator 210 was formed of wrinkled media, made with 2 layers of around 7.0 microns effective fiber diameter (EFD), with a basis weight of 18 grams per square meter (gsm), with a 200% stretch ratio, where the stretch ratio indicates the stretch value of the filaments during manufacture of the wrinkled filter media. [0090] FIGS.5B-1 and 5B-2 illustrate a second cup-style respirator 220. Respirator 220 was formed of wrinkled media, having 2 layers of around 7.0 EFD, with a basis weight of 18 gsm, and with a 100% stretch ratio. [0091] FIG.5C-1 illustrates a third cup-style respirator 230. Respirator 230 was formed of wrinkled media, having 2 layers of around 7.0 EFD, with a basis weight of 18 gsm, and with a 50% stretch ratio. [0092] FIG.5C-2 illustrates a fourth cup-style respirator 240. Respirator 240 was formed of wrinkled media, having 2 layers of around 6.5 EFD, with a basis weight of 16 gsm, and with a 200% stretch ratio. [0093] FIG. 5C-3 illustrates a fifth cup-style respirator 250, formed of wrinkled media, having one layer of fibrillated film fibers with rectangular cross-section of approximately 10 microns x 40 microns, 150 gsm basis weight, and one layer of BMF fibers with 7.5 EFD, 61 gsm basis weight, and having 100% stretch ratio. [0094] FIGS.5D-1 and 5D-2 illustrate a sixth cup-style respirator 260 with a “skip-slit” formed shell. Generally, cup-shaped respirators require a forming or molding process to create the permanent “cup” shape. The cup shape provides a rigid structural support, reduces the risk of collapse and increases crush resistance. The cup-shaped shell layer can be an interior layer (e.g. face side as in 3M® 8210 N95) or an exterior layer (e.g. 3M® 8511 N95). As used herein, a skip-slit shell refers to a 3- Dimensional respirator shell formed from a reticulated 2-Dimensional continuous nonwoven fabric. The shell has a mesh-like open pattern. The reticulated pattern is formed by cutting or slitting a desired pattern into a web. A skip-slit shell, when used with wrinkled media, may allow for cup- shaped respirators to have sufficient flexibility to be substantially flattened for storage and sufficient resilience to spring back to the original cup shape. [0095] FIG. 5D-1 illustrates a skip-slit shell 262 that is incorporated into the cup-shape respirator 260 illustrated in FIG. 5D-2. The skip-slit shell is less stiff than the shell in a 3M® 8210 N95 respirator but provides adequate support to filter media with the flexibility of increased stretchability and sufficient resilience to spring back to the formed shape. Respirator 260 is composed of wrinkled media of 2 layers of 7.5 EFD, 61 gsm, at 200% stretch ratio, with a skip-slit formed shell. [0096] FIGS. 5E-1 and 5E-2 illustrate a reticulated shell that may be used in embodiments herein. Specifically, FIGS.5E-1 and 5E-2 illustrate a shell formed from an elastic net. Shell 272 is resilient, such that when pressed flat, it springs back into a dome-like configuration. FIGS. 5E-3 and 5E-4 illustrated a shell 272 integrated into a seventh cup-style respirator 270. Cup-style respirator 270 includes wrinkled media and, in some embodiments, a shell formed of an elastic that forms the cup shell shape. The elastic net shell 272 is flexible, stretchable, and collapsible for more compact storage when compressed, and has sufficient resilience to spring back to the original molded cup shape. [0097] The wrinkled media in the embodiment illustrated in FIG. 5E-3 was formed of 2 layers of BMF media with around 6.5 EFD fibers, 18 gsm basis weight, and 200% stretch ratio. The layers were point-bonded with the elastic net shell 272 along the perimeter of cup 270, allowing for the cup perimeter to also be stretchable. The respirator 270 illustrated in FIG.5E-3 had a side rest height 274 of about 2,” that could be stretched to about 2.5” tall. Respirator 270 also had a center rest height (the distance from respirator nose contact point to chin contact point) 276 of about 4”, and could be stretched to about 5.5”. that the ability to stretch a respirator helps accommodate the wearer’s facial movement while talking or laughing or yawning and allows for better conformability and fit. In embodiments herein, a center rest height (measured from a nose contact point to a chin contact point) of a respirator can be resiliently stretched at least 10%, at least 20%, or at least 30%. [0098] Additional features may be added to the cup-shaped respirators. For example, elastic woven material cab be added to the sides to increase comfort and to allow for cosmetic identification. In another example, the wrinkled media may be folded to further increase surface area. [0099] The cup-shaped respirators 210, 220, and 230 were designated EX 1, EX 2 and EX 3 in Table 3 respectively. These respirators used wrinkled media made of 2 layers of web F4 at stretch ratio of 200%, 100% and 50% respectively. CE 1 was a cup-shaped respirator available under the trade designation “3M Disposable Respirator 1860” available from 3M Company, Maplewood, MN, USA. CE 2 was a cup-shaped respirator available under the trade designation “3M Disposable Respirator 8210” available from 3M Company, Maplewood, MN, USA. The samples were tested following the Initial Percent Penetration, Pressure Drop and Quality Factor Test using NaCl particles. The results are shown in Table 3. Table 3 Sample Respirator Used Initial dP Initial QF (mmH2O) %Pen EX 1 210 2.55 0.138 2.6 EX 2 220 2.4 0.143 2.7 EX 3 230 2.6 0.085 2.7 CE 1 1860 8.3 0.190 0.8 CE 2 8210 8.1 0.413 0.7 [00100] The cup-shaped respirators 240, designated EX 4 in Table 4, was made with wrinkled media that include 2 layers of web F1 at a stretch ratio of 200%. One respirator, designated EX 5 in Table 4, was made with two layers of wrinkled media used in 240.The respirator 270, designated EX 6, was made with the same wrinkled media used in 240 and the shell made of elastic net. These respirators were tested for their initial pressure drop using NaCl particles and the results are shown in Table 4. Table 4 Sample Respirator Used Initial dP (mmH₂O) EX 4 240 2.7 E^{X 5 2 layers of wrinkled} m_{edia used in EX 4} ^5.75 EX 6 270 2.5 [00101] The cup-shaped respirators 250, designated EX 7 in Table 5, was made of shirred media of one layer of web F5 and one layer of web F2 at stretch ration of 100%. It was tested for its initial pressure drop, percent penetration, and loading capacity using NaCl particles. A comparative respirator CE 3 was made with the same webs F5 and F2 in non-wrinkly format. They were tested for the initial and loading pressure drops and penetration in NaCl tests. The test results are shown in Table 5. Table 5 Sample Respirator Initial dP Initial QF Final dP Final %Pen Used (mmH2O) %Pen (mmH2O) At 100 mg of NaCl loading E_{X 7 250 7.0 0.000} ^1.3 _9.2 ^0.44 C_{E 3 1860 7.3 0.009} ^0.7 _13.3 ^0.77 [00102] The Aura®-Style respirators 100, 140, and 180 were designated EX 8, EX 9 and EX 10 in Table 6 respectively. The respirator 100 had wrinkled media made of 2 layers of web F1 at stretch ratio of 200% as the middle panel. The respirator 140 used the same wrinkled media as respirator 100 and had the wrinkled media as the middle and bottom panels, with the wrinkles oriented in generally perpendicular directions when respirator was folded flat. The respirator 180 used the same wrinkled media as respirator 100 and had the wrinkled media as the middle and bottom panels, with the wrinkles oriented in generally parallel directions when respirator was folded flat. CE 4 was an Aura®-style respirator available under the trade designation “3M Disposable Respirator Aura® 1870+” available from 3M Company., Maplewood, MN, USA. These samples were tested for their initial pressure drop using NaCl particles. The results are shown in Table 6. Table 6 Sample Respirator Used Initial dP (mmH2O) EX 8 100 4.2 EX 9 140 4.9 EX 10 180 4.0 CE 4 1870+ 8.2 [00103] Each of prototypes 1-3 (5A-5C) illustrated both a lower pressure drop and an improved quality factor when compared to commercially available respirators. [00104] As demonstrated in Tables 12 and 4, there is a significant pressure drop reduction in prototype respirators with wrinkled media. The pressure drops of cup prototypes are less than ½ of the commercialized 3M cup respirators (less than 3 mmH₂O vs. greater than 8 mmH₂O). The pressure drops of flat-fold respirators with wrinkled media are about half of the commercialized 3M Aura respirator (about 4.5 mmH₂O vs. greater than 8 mmH₂O). [00105] Additionally, as illustrated in Table 3, there are significant reduction in pressure drop (9.2 mmH₂O vs. 13.3 mmH₂O) and penetration (0.44% vs.0.77%) during NaCl particle loading for respirators with wrinkled media. [00106] FIGS. 6A-6C illustrate other respirator styles that may benefit from the inclusion of wrinkled media. While horizontal flat fold and cup-shape respirator embodiments are described in detail herein, it is noted that other respirator styles may benefit from incorporation of wrinkled media. [00107] FIG. 6A illustrates a vertical-fold style respirator 310, which is designed to fold flat along crease 312. Respirator 310 may be composed of wrinkled media, in accordance with embodiments herein, increasing its stretchability, decreasing breathing resistance leading to improved comfort. [00108] FIG. 6B illustrates a pleated style respirator 320 (for example, available from 3M Company under the trade name VFLEX®), for example such as that illustrated in US Pat. No. 8,640,704, FIGS. 1-4 and column 4, line 25 – column 5, line 29, incorporated herein by reference. Pleated style respirator 320 is foldable along a centerline. Respirator 320 has a mask body that has a transversely-extending line of demarcation with a longitudinal axis. One or more weld patterns may be disposed above and not traversing the line of demarcation. The one or more weld patterns may be disposed on each side of the longitudinal axis. In some embodiments, an additional one or more weld patterns are disposed below, and not crossing, the line of demarcation on each side of the longitudinal axis. Any, all, or a subset of welds are a two-dimensional enclosed pattern. Weld patterns for respirator 320 may have a truss-type geometry, one or more triangles, with either sharp or rounded corners. Weld patterns may have other shapes as well. Weld pattern shapes may be present in multiple size, multiple orientations, or both. Shapes may overlap, share edges or corners, or be nested within each other, in some embodiments. [00109] FIG.6C illustrates a “duck-bill”-style respirator 330. A “duck-billed” style respirator may be similar to that described in U.S. Pat 5,322,061 to Brunson. Such as respirator can be characterized as having a generally trapezoidal portion forming an upper half of the respirator, which contacts the wearer’s nose, as well as a generally trapezoidal portion forming a lower half of the respirator, which contact the wearer’s chin. [00110] While several different respirator designs are illustrated in FIGS. 4-6, it is expressly contemplated that other respiratory designs may also benefit from including wrinkled media. For example, a unitary mask, formed without welding, bonding, or stitching different panels together, such as that illustrated in US PAP 2015/0173436 to Tsuei. In another example, wrinkled media can be used in reusable respirators such as those available under the trade designation “3M Reusable Respirator 7744 or 7711K” available from 3M Company, Maplewood, MN, USA. The media with wrinkled layer(s) is encased by the respirator holder. While the media can be replaced, the respirator holder or case is reusable. Other respirator designs are also contemplated. [00111] Respirators described and illustrated in FIGS.4-6 may be composed of multiple layers of material, some or all of which may be composed of wrinkled media. The layers of respirators may be joined by weld, point-weld, bond, point-bond, stitched seam or another suitable method. In some embodiments, wrinkled media is combined with flat sheet media and / or pleat packs to maximize advantages of each media configuration. In some embodiments, respirator models herein include wrinkled media in a face seal area which can absorb sweat and improve comfort. In some embodiments, respirators described herein may include an antifog band along the upper section of the respirator to prevent eyewear fogging. In some embodiments. respirators herein include a stay- in-place tape along the nose area to improve fit by preventing respirator movement along the nose bridge. In some embodiments, respirators herein include a breathing or exhaust valve. In some embodiments, respirators herein include a headband, straps and / or earloops. [00112] While respirators herein are illustrated as having white filaments in the wrinkled media, it is expressly contemplated that naturally colored, or dyed filaments may be used – for example to visually differentiate models of respirators. [00113] FIG. 7 illustrates a representation of a respirator wearer that may benefit from embodiments described herein. A respirator should seal completely to the face 700 in order to be effective. The perimeter of the seal is referred to as a racetrack 710. For contemporary masks currently available, the racetrack 710 of a given respirator model does not substantially change, as media layers do not stretch significantly. Additionally, most respirators have media layers that are sealed together such that the racetrack cannot significantly expand. [00114] However, embodiments herein, made with wrinkled media, experience significant stretchability, as illustrated in FIGS.4D-4E, which allows for a wearer 700 to change the shape, and perimeter size, of racetrack 710, e.g. as indicated by arrows 720. Wearer 700 may stretch a respirator linearly, e.g. along axis 730. This may allow for the respirator to stretch further over wearer’s chin, increasing comfort. [00115] Disposable respirators composed of different layers or panels are generally sealed along a perimeter of the respirator to ensure that air is forced through the filter material. Often the seal is made using welding, bonding or stitching a seam. Some embodiments herein, however, are sealed using point-welding or point-bonding, in some embodiments, to create a sufficient seal while allowing the respirator to stretch. Some embodiments use an elastic filament to form the seam, such that the elastic filament can stretch with the wrinkled media. [00116] In some embodiments, a respirator has sufficient stretchability such that a racetrack perimeter can increase by at least 10%, and is resilient enough such that it returns to its original size. In some embodiments, a respirator has sufficient stretchability such that a racetrack perimeter can increase by at least 20%, at least 30%, at least 40% or at least 50% and is resilient enough such that it returns to its original size. In some embodiments, a respirator has sufficient stretchability such that a racetrack perimeter can increase by at least 60%, at least 70%, at least 80% or at least 90% and is resilient enough such that it returns to its original size. In some embodiments, a respirator has sufficient stretchability such that a racetrack perimeter can increase by at least 100%, and is resilient enough such that it returns to its original size. [00117] Stretchability of respirator models may vary. For example, cup-shape respirators may have less stretchability than other models, due to the cup-shape. In some embodiments, a racetrack perimeter of a cup-shaped respirator in embodiments herein can increase by at least 10%, at least 20%, at least 30%, or even at least 40%, with sufficient resilience to return to its original size. [00118] n some embodiments a length of a respirator, measured from a contact point of the seal at the nose bridge to a contact point of the seal at the center of the chin, can stretch by more than 10%, and is resilient such that it returns to the original length. [00119] FIG. 8 illustrates a method of making a respiratory protection device in accordance with embodiments herein. Method 800 may be used to make any of the respirator types illustrated in FIGS.4-7. [00120] At block 810, respirator media is obtained. Wrinkled media 812 may be obtained for one or more layers or panels. Flat media 814 may be obtained for one or more layers or panels. Other media 816 may also be used. For example, media with anti-fog properties may be obtained for a portion of the respirator. Alternatively, a skit-slip layer may be obtained to use as a shell. [00121] At block 820, one or more treatments are performed on one or more of the layers. For example, a cup shell may be preformed 822. One or more layers may be charged 824 to exhibit electret properties attracting and binding particulates and liquid droplets. Other treatments 826 may be performed. [00122] A preform step, required for cup-shape respirators, can be a rate-limiting step in the manufacture of respirators as curvature must be formed in multiple directions, which may include cutting and welding in a sinusoidal shape. It is noted that some embodiments herein using a dashed- line slitted layer (sometimes referred to as a skip slit layer) to form the cup-shape structure do not require a preform step. [00123] A dashed-line slitted layer is composed of a surface that has been cut through (e.g. slit) in a dashed-line pattern. One example is illustrated in FIG.5D-1. However, while the dashed- line-pattern of FIG. 5D-1 includes adjacent lines having dashes offset from one another, it is expressly contemplated that other patterns are possible. US PAP 2019/0187345 A1 describes and illustrates a number of patterns that may be used in embodiments herein. The slit pattern may be a diamond slit pattern, for example as illustrated in FIGS. 1-4 and 12 of US 2019/0187345 A1, incorporated herein by reference. The slit pattern may also have non-diamond slit patterns that also allow for expansion in at least one direction, for example as illustrated in FIGS.5, 8, 10, 11 and 14, of US2019/0187345 A1, incorporated herein by reference. The slit pattern may also have two different size or shape openings, as illustrated in FIGS. 6 and 15 of US 2019/0187345 A1, incorporated herein by reference. The slit pattern may also have three different size or shape openings, as illustrated in FIGS. 7, 9 and 13 of US 2019/0187345 A1, incorporated herein by reference. The slit pattern may also have two different size or shape openings that allow expansion in two directions as illustrated in FIGS. 16 and 18 of US 2019/0187345 A1. The slit pattern may also have three different size or shape openings that converge to provide expansion in at least three directions, as illustrated in FIG.19 of US20190187345A1. [00124] However, while FIG.5D-1 illustrates a dashed-line slitted layer that can be used as a shell, other solutions may also be used. In some embodiments, an elastic net may be used as a shell. An elastic net may be formed by molding, extrusion, or another suitable method. [00125] At block 830, a layer stack is formed. The layer stack may be composed 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 another suitable shell component. The layer stack may include a layer 838 with sorbent incorporated that can adsorb or absorb gases, vapor, etc. One example of a sorbent often used in filtration is activated carbon. The layer with active carbons may be a wrinkled media layer. The active carbon layer may be a separate layer, e.g. with carbon or another suitable sorbent attached to the surface of fibrous web. Other layers 839 maybe present such as fluid resistant layers or stiffening layers. While active carbon is described here as one sorbent material, it is expressly contemplated that other sorbent materials may be suitable. For example, a polymeric sorbent could be used in embodiments herein. [00126] At block 840, the layer stack is sealed. Sealing the layer stack may include applying a weld 842, seam 844, bond 846 or other suitable method 848. Additionally, while a weld 842 or bond 844 are illustrated, it is expressly contemplated that these may not be complete – e.g. a dashed or point weld or bond may be used in embodiments herein, which would allow for stretching along the sealed edge. Similarly, the stretching along the sealed edge is desired, a seam 844 may include an elastic filament. The sealing occurs such that each layer is in intimate contact with adjacent layers. Suitable welding techniques are known in the art and include thermal bonding or ultrasonic welding. [00127] At block 850, accessories are added. A nose clip 852 may be applied. The nose clip may serve to mold a respirator so that a seal forms with a 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 portion 854 may also be added to increase comfort and improve seal. For example, custom nose foams are described in PCT Publication WO 2022/235472, published on November 10, 2022, however other foam types and positions are contemplated. An exhalation valve 856 may be added. In some embodiments, a valve-containing portion of a respirator has less stretch than a valve-less portion. A harness 858, for holding the respirator in contact with a wearer’s face, may be applied. In some embodiments, the harness 858 includes straps or earloops that are integral to a wrinkled media layer of the respirator. In some embodiments, the harness 858 is a separate component welded, stapled, adhered or otherwise coupled to the respirator body. Other accessories 859 may also be added. [00128] Wrinkled media is a new structured input filtration material for respirators. It enables larger surface area with compact profile. With proper respirator design such as multi-panel or support shell, the resulting respirator can have low breathing resistance and higher particle loading capacity with good stretchability. In some embodiments, the respirator can also be folded to flat. This is an improvement over previous respirator designs, which either used plastic structures to support extra filter media to give it stretchability (but made them bulky and not foldable) or using corrugated media to help breathing resistance (but not stretchable or foldable). [00129] Wrinkled media may be used in a number of disposable respirator models in order to provide improved breathability while maintaining high filter capacity. Some examples of respirator models that may benefit from wrinkled media include: tri-fold respirators (as illustrated in FIGS.4A- 4E), cup-shaped respirators (as illustrated in FIGS.5A-5E), vertical fold respirators (as illustrated in FIG. 6A), flat fold respirators, pleated respirators (as illustrated in FIG. 6B), and “duck-bill” respirators (as illustrated in FIG.6C). [00130] Using wrinkled media to form one or more layers of a respirator for a respirator to have a compact, high-surface-area filter which provides increased comfort and flexibility. [00131] Foreseeable modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention. This invention should not be restricted to the embodiments that are set forth in this application for illustrative purposes. To the extent that there is any conflict or discrepancy between this specification as written and the disclosure in any document mentioned or incorporated by reference herein, this specification as written will prevail. [00132] A horizontal flat-fold respirator is presented that includes a layer of wrinkled media. The wrinkled media includes a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous web. The first non-woven porous web is directly bonded to the second non-woven porous web. At least one portion of the wrinkled media is resiliently extensible under tension. [00133] The respirator may further include a top panel configured to seal around a nose of a user, a bottom panel configured to seal around a chin of a user, a center panel, the center panel includes a top edge and a bottom edge, the center panel seals to the top panel along the top edge, and the center panel seals to the bottom panel along the bottom edge. [00134] The respirator may be constructed such that it can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 10% longer than the resting height. [00135] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 30% longer than the resting height. [00136] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 40% longer than the resting height. [00137] The respirator may be constructed such that the pressure drop across the respirator filter at 85 LPM air flow rate is less than 6 mmH2O. [00138] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 5 mmH2O. [00139] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 4 mmH2O. [00140] The respirator may be constructed such that the respirator has a quality factor greater than 2 at an air flow rate of 85 LPM. [00141] The respirator may be constructed such that the respirator has a quality factor greater than 2.2 at a at an air flow rate of 85 LPM. [00142] The respirator may be constructed such that the respirator has a quality factor greater than 1.8 at a at an air flow rate of 85 LPM. [00143] The respirator may be constructed such that the respirator has a quality factor greater than 1.6 at a at an air flow rate of 85 LPM. [00144] The respirator may be constructed such that the center panel includes the layer of wrinkled media. [00145] The respirator may be constructed such that two of the top panel, bottom panel and center panel include the layer of wrinkled media. [00146] The respirator may be constructed such that one of the top panel, bottom panel and center panel include unwrinkled nonwoven media. [00147] The respirator may be constructed such that one of the top panel, bottom panel and center panel include wrinkled and unwrinkled nonwoven media. [00148] The respirator may be constructed such that it also includes a shell layer having a resilient material. [00149] The respirator may be constructed such that the shell layer includes a reticulated material. [00150] The respirator may be constructed such that the shell layer includes dashed-line slits. [00151] The respirator may be constructed such that the shell layer includes an elastic net. [00152] The respirator may be constructed such that the shell includes an extruded material. [00153] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00154] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00155] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00156] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00157] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 50% longer than a resting racetrack perimeter. [00158] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 60% longer than a resting racetrack perimeter. [00159] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 70% longer than a resting racetrack perimeter. [00160] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 80% longer than a resting racetrack perimeter. [00161] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 90% longer than a resting racetrack perimeter. [00162] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 100% longer than a resting racetrack perimeter. [00163] The respirator may be constructed such that it also including a stiffening layer. [00164] The respirator may be constructed such that it also including sorbent particles. [00165] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane. [00166] The respirator may be constructed such that one of the first and second nonwoven layers includes a fibrous nonwoven material. [00167] The respirator may be constructed such that it includes a cover web layer. [00168] The respirator may be constructed such that the seal is a weld, point-weld, bond, point- bond, or seam. [00169] The respirator may be constructed such that the seal substantially inhibits stretching along the edge. [00170] The respirator may be constructed such that seal does not substantially inhibit stretching along the edge. [00171] The respirator may be constructed such that it includes: a nose clip, a foam layer, a valve, or a harness. [00172] The respirator may be constructed such that it also includes a strap, and the strap, in combination with one of the top, bottom or center panel, forms a unitary wrinkled media article. [00173] A cup-shape respirator is presented that includes a layer of wrinkled media. The wrinkled media includes: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous web. The first non-woven porous fibrous web is directly bonded to the second non-woven porous web. At least one portion of the wrinkled media is resiliently extensible under tension. [00174] The respirator may be constructed such that it includes a formed portion that, in a first state, includes curvature in multiple directions. [00175] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 10% longer than the resting height. [00176] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 30% longer than the resting height. [00177] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 40% longer than the resting height. [00178] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O. [00179] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 2.8 mmH2O. [00180] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 2.7 mmH2O. [00181] The respirator may be constructed such that the respirator has a quality factor greater than 2 at an air flow rate of 85 LPM. [00182] The respirator may be constructed such that the respirator has a quality factor greater than 2.2 at a at an air flow rate of 85 LPM. [00183] The respirator may be constructed such that the respirator has a quality factor greater than 1.8 at a at an air flow rate of 85 LPM. [00184] The respirator may be constructed such that the respirator has a quality factor greater than 1.6 at a at an air flow rate of 85 LPM. [00185] The respirator may be constructed such that the respirator has a quality factor greater than 2.4 at a at an air flow rate of 85 LPM. [00186] The respirator may be constructed such that the respirator has a quality factor greater than 2.5 at a at an air flow rate of 85 LPM. [00187] The respirator may be constructed such that it includes a shell layer. [00188] The respirator may be constructed such that the shell layer is an outer layer. [00189] The respirator may be constructed such that the shell layer is an inner layer. [00190] The respirator may be constructed such that the shell layer includes a reticulated material. [00191] The respirator may be constructed such that the shell layer includes dashed-line slits. [00192] The respirator may be constructed such that the shell layer includes an elastic net. [00193] The respirator may be constructed such that the respirator is resilient such that the curvature recovers after a force is applied to the curvature. [00194] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00195] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00196] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00197] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00198] The respirator may be constructed such that it includes sorbent particles. [00199] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane. [00200] The respirator may be constructed such that one of the first and second nonwoven layers includes a fibrous nonwoven material. [00201] The respirator may be constructed such that it includes a cover web layer. [00202] The respirator may be constructed such that a nose clip, a foam layer, a valve, or a harness. [00203] The respirator may be constructed such that it includes a strap, and the strap, in combination with the layer of wrinkled media, forms a unitary wrinkled media article [00204] A vertical fold respirator is presented that includes a layer of wrinkled media. The wrinkled media includes: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous fibrous web. The first non-woven porous fibrous web is directly bonded to the second non-woven porous fibrous web. At least one portion of the wrinkled media is resiliently extensible under tension. [00205] The respirator may be constructed such that the respirator is configured to fold flat along a centerline. [00206] The respirator may be constructed such that the respirator can be stretched from a resting length to a stretched length, and recover to the resting length, and the stretched length is 10% longer than the resting length. [00207] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00208] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00209] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00210] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 50% longer than a resting racetrack perimeter. [00211] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 60% longer than a resting racetrack perimeter. [00212] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 70% longer than a resting racetrack perimeter. [00213] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 80% longer than a resting racetrack perimeter. [00214] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 90% longer than a resting racetrack perimeter. [00215] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 100% longer than a resting racetrack perimeter. [00216] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 3.0 mmH2O. [00217] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 2.8 mmH2O. [00218] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 2.7 mmH2O. [00219] The respirator may be constructed such that the respirator has a quality factor greater than 2 at an air flow rate of 85 LPM. [00220] The respirator may be constructed such that the respirator has a quality factor greater than 2.2 at an air flow rate of 85 LPM. [00221] The respirator may be constructed such that the respirator has a quality factor greater than 1.8 at an air flow rate of 85 LPM. [00222] The respirator may be constructed such that the respirator has a quality factor greater than 1.6 at an air flow rate of 85 LPM. [00223] The respirator may be constructed such that the respirator has a quality factor greater than 2.4 at an air flow rate of 85 LPM. [00224] The respirator may be constructed such that the respirator has a quality factor greater than 2.5 at an air flow rate of 85 LPM. [00225] The respirator may be constructed such that it includes a shell layer. [00226] The respirator may be constructed such that the shell layer is an outer layer. [00227] The respirator may be constructed such that the shell layer is an inner layer. [00228] The respirator may be constructed such that the shell layer includes a reticulated material. [00229] The respirator may be constructed such that the shell layer includes dashed-line slits. [00230] The respirator may be constructed such that the shell layer includes an elastic net. [00231] The respirator may be constructed such that the shell layer includes an extruded net. [00232] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00233] The respirator may be constructed such that it includes a sorbent particles. [00234] The respirator may be constructed such that it includes a cover web layer. [00235] The respirator may be constructed such that it includes: a nose clip, a foam layer, a valve, or a harness. [00236] The respirator may be constructed such that it includes a strap, and the strap, in combination with the layer of wrinkled media, forms a unitary wrinkled media article. [00237] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane. [00238] The respirator may be constructed such that one of the first and second nonwoven layers includes a fibrous nonwoven material. [00239] A duckbill respirator is presented that includes a layer of wrinkled media. The wrinkled media includes: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous fibrous web. The first non-woven porous fibrous web is directly bonded to the second non-woven porous fibrous web. At least one portion of the wrinkled media is resiliently extensible under tension. [00240] The respirator may be constructed such that the respirator is configured to fold flat along a centerline. [00241] The respirator may be constructed such that it includes a first generally trapezoidal portion configured to contact a nose of a wearer and a second generally trapezoidal portion configured to contact a chin of a wearer. One of the first and second generally trapezoidal portions includes the layer of wrinkled media. [00242] The respirator may be constructed such that the respirator can be stretched from a resting length to a stretched length, and recover to the resting length, and the stretched length is 10% longer than the resting length. [00243] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 30% longer than the resting height. [00244] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 40% longer than the resting height. [00245] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O. [00246] The respirator may be constructed such that the respirator has a quality factor greater than 2 at an air flow rate of 85 LPM. [00247] The respirator may be constructed such that the respirator has a quality factor greater than 2.2 at a at an air flow rate of 85 LPM. [00248] The respirator may be constructed such that the respirator has a quality factor greater than 1.8 at a at an air flow rate of 85 LPM. [00249] The respirator may be constructed such that the respirator has a quality factor greater than 1.6 at a at an air flow rate of 85 LPM. [00250] The respirator may be constructed such that the respirator has a quality factor greater than 2.4 at a at an air flow rate of 85 LPM. [00251] The respirator may be constructed such that the respirator has a quality factor greater than 2.5 at a at an air flow rate of 85 LPM. [00252] The respirator may be constructed such that it includes a shell layer. [00253] The respirator may be constructed such that the shell layer is an outer layer. [00254] The respirator may be constructed such that the shell layer is an inner layer. [00255] The respirator may be constructed such that the shell layer includes a reticulated material. [00256] The respirator may be constructed such that the shell layer includes dashed-line slits. [00257] The respirator may be constructed such that the shell layer includes an elastic net. [00258] The respirator may be constructed such that the elastic net is an extruded elastic net. [00259] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00260] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00261] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00262] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00263] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 50% longer than a resting racetrack perimeter. [00264] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 60% longer than a resting racetrack perimeter. [00265] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 70% longer than a resting racetrack perimeter. [00266] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 80% longer than a resting racetrack perimeter. [00267] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 90% longer than a resting racetrack perimeter. [00268] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 100% longer than a resting racetrack perimeter. [00269] The respirator may be constructed such that it includes a sorbent layer. [00270] The respirator may be constructed such that it includes a cover web layer. [00271] The respirator may be constructed such that it includes: a nose clip, a foam layer, a valve, or a harness. [00272] The respirator may be constructed such that it includes a strap, and the strap, in combination with the layer of wrinkled media, forms a unitary wrinkled media article. [00273] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane. [00274] The respirator may be constructed such that one of the first and second nonwoven layers includes a fibrous nonwoven material. [00275] A pleated respirator is presented that includes a layer of wrinkled media. The wrinkled media includes: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous fibrous web. The first non-woven porous fibrous web is directly bonded to the second non-woven porous fibrous web. At least one portion of the wrinkled media is resiliently extensible under tension. [00276] The respirator may be constructed such that the respirator further includes a mask body that has a transversely-extending line of demarcation, a longitudinal axis, first and second weld patterns disposed above and not traversing the line of demarcation on each side of the longitudinal axis, respectively, and third and fourth weld patterns disposed below and not crossing the line of demarcation on each side of the longitudinal axis, respectively. Each of the first, second, third, and fourth weld patterns is a two-dimensional enclosed pattern [00277] The respirator may be constructed such that the respirator is configured to fold flat along a centerline. [00278] The respirator may be constructed such that the respirator can be stretched from a resting length to a stretched length, and recover to the resting length, and the stretched length is 10% longer than the resting length. [00279] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 30% longer than the resting height. [00280] The respirator may be constructed such that the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 40% longer than the resting height. [00281] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O. [00282] The respirator may be constructed such that the respirator has a quality factor greater than 2 a at an air flow rate of 85 LPM. [00283] The respirator may be constructed such that the respirator has a quality factor greater than 2.2 at an air flow rate of 85 LPM. [00284] The respirator may be constructed such that the respirator has a quality factor greater than 1.8 at an air flow rate of 85 LPM. [00285] The respirator may be constructed such that the respirator has a quality factor greater than 1.6 at an air flow rate of 85 LPM. [00286] The respirator may be constructed such that the respirator has a quality factor greater than 2.4 at an air flow rate of 85 LPM. [00287] The respirator may be constructed such that the respirator has a quality factor greater than 2.5 at an air flow rate of 85 LPM. [00288] The respirator may be constructed such that it includes a shell layer. [00289] The respirator may be constructed such that the shell layer is an outer layer. [00290] The respirator may be constructed such that shell layer is an inner layer. [00291] The respirator may be constructed such that the shell layer includes a reticulated material. [00292] The respirator may be constructed such that the shell layer includes dashed-line slits. [00293] The respirator may be constructed such that the shell layer includes an extruded net. [00294] The respirator may be constructed such that the elastic net is an extruded elastic net. [00295] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00296] The respirator may be constructed such that it also includes a sorbent layer. [00297] The respirator may be constructed such that it also includes a cover web layer. [00298] The respirator may be constructed such that it also includes a nose clip, a foam layer, a valve, or a harness. [00299] The respirator may be constructed such that it includes a strap. [00300] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane. [00301] The respirator may be constructed such that one of the first and second nonwoven layers includes a fibrous nonwoven material. [00302] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00303] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00304] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00305] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00306] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 50% longer than a resting racetrack perimeter. [00307] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 60% longer than a resting racetrack perimeter. [00308] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 70% longer than a resting racetrack perimeter. [00309] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 80% longer than a resting racetrack perimeter. [00310] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 90% longer than a resting racetrack perimeter. [00311] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 100% longer than a resting racetrack perimeter. [00312] A method of making a respirator is presented that includes obtaining a wrinkled media article and forming a stack of media layers. The wrinkled media article is a wrinkled layer within the stack of media layers. The method also includes sealing the stack of media layers. When sealed, the stack of media layers have a resting racetrack perimeter length, and can resiliently stretch to a stretched racetrack perimeter, and the stretched racetrack perimeter is 10% greater than the resting racetrack perimeter. [00313] The method may be implemented such that it includes preforming the stack of media layers. Preforming forms the stack of media layers into a cup-shape. [00314] The method may be implemented such that one layer of the stack of media layers includes a shell layer. [00315] The method may be implemented such that the shell layer is an outer layer with respect to the wrinkled layer. [00316] The method may be implemented such that the shell layer is an inner layer with respect to the wrinkled layer. [00317] The method may be implemented such that the shell layer includes a reticulated open mesh. [00318] The respirator may be implemented such that the shell layer includes dashed-line slits. [00319] The respirator may be implemented such that the shell layer includes an extruded net. [00320] The method may be implemented such that the shell layer has a resting shape and, after a force deforms the resting shape, recovers to the resting shape. [00321] The method may be implemented such that it includes adding one of a nose clip, a foam layer, a valve, or a harness to the stack of media layers before or after sealing. [00322] The method may be implemented such that sealing includes welding, point-welding, bonding, or point-bonding, or forming a seam. [00323] The method may be implemented such that the stack of layer further includes one of a cover web, a sorbent layer, a filter layer, or a shell layer. [00324] The method may be implemented such that it includes charging the wrinkled filter layer. [00325] The method may be implemented such that it includes charging all additional filter layers of the respirator. [00326] The method may be implemented such that the respirator is a horizontal tri-fold respirator. [00327] The method may be implemented such that the respirator is a vertical fold respirator. [00328] The method may be implemented such that the respirator is a cup-shape respirator. [00329] The method may be implemented such that the respirator is a pleated respirator. [00330] The method may be implemented such that the respirator is a duck-bill respirator. [00331] The method may be implemented such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 3.0 mmH2O. [00332] The method may be implemented such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 2.8 mmH2O. [00333] The method may be implemented such that the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 2.7 mmH2O. [00334] The method may be implemented such that the respirator has a quality factor greater than 2 at an air flow rate of 85 LPM. [00335] The method may be implemented such that the respirator has a quality factor greater than 2.2 at an air flow rate of 85 LPM. [00336] The method may be implemented such that the respirator has a quality factor greater than 1.8 at an air flow rate of 85 LPM. [00337] The method may be implemented such that the respirator has a quality factor greater than 1.6 at an air flow rate of 85 LPM. [00338] The method may be implemented such that the respirator has a quality factor greater than 2.4 at an air flow rate of 85 LPM. [00339] The method may be implemented such that the respirator has a quality factor greater than 2.5 at an air flow rate of 85 LPM. [00340] The method may be implemented such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00341] The method may be implemented such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00342] The method may be implemented such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00343] The method may be implemented such that a stretched racetrack perimeter of the respirator is 50% longer than a resting racetrack perimeter. [00344] The method may be implemented such that a stretched racetrack perimeter of the respirator is 60% longer than a resting racetrack perimeter. [00345] The method may be implemented such that a stretched racetrack perimeter of the respirator is 70% longer than a resting racetrack perimeter. [00346] The method may be implemented such that a stretched racetrack perimeter of the respirator is 80% longer than a resting racetrack perimeter. [00347] The method may be implemented such that a stretched racetrack perimeter of the respirator is 90% longer than a resting racetrack perimeter. [00348] The method may be implemented such that a stretched racetrack perimeter of the respirator is 100% longer than a resting racetrack perimeter. [00349] The method may be implemented such that one of the first and second nonwoven layers includes a membrane. [00350] The method may be implemented such that one of the first and second nonwoven layers includes a fibrous nonwoven material. [00351] A respirator including a layer of wrinkled media is presented. [00352] The respirator may be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 10% longer than the resting height. [00353] The respirator may be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 30% longer than the resting height. [00354] The respirator may be stretched from a resting height to a stretched height, and recover to the resting height, and the stretched height is at least 40% longer than the resting height. [00355] The respirator may be constructed such that the layer of wrinkled media includes a first series of substantially parallel non-bonded elastic filaments between a first and a second non- woven porous fibrous web. The first non-woven porous fibrous web is directly bonded to the second non-woven porous fibrous web. At least one portion of the wrinkled media is resiliently extensible under tension. [00356] The respirator may be constructed such that the respirator is configured to fold flat along a centerline. [00357] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O. [00358] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 2.8 mmH2O. [00359] The respirator may be constructed such that the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 2.7 mmH2O. [00360] The respirator may be constructed such that the respirator has a quality factor greater than 2 at an air flow rate of 85 LPM. [00361] The respirator may be constructed such that the respirator has a quality factor greater than 2.2 at an air flow rate of 85 LPM. [00362] The respirator may be constructed such that the respirator has a quality factor greater than 1.8 at an air flow rate of 85 LPM. [00363] The respirator may be constructed such that the respirator has a quality factor greater than 1.6 at an air flow rate of 85 LPM. [00364] The respirator may be constructed such that the respirator has a quality factor greater than 2.4 a at an air flow rate of 85 LPM. [00365] The respirator may be constructed such that the respirator has a quality factor greater than 2.5 a at an air flow rate of 85 LPM. [00366] The respirator may be constructed such that it includes a shell layer. [00367] The respirator may be constructed such that it includes an outer layer. [00368] The respirator may be constructed such that the shell layer is an inner layer. [00369] The respirator may be constructed such that the shell layer includes a reticulated material. [00370] The respirator may be constructed such that the shell layer includes dashed-line slits. [00371] The respirator may be constructed such that the shell layer includes an elastic net. [00372] The respirator may be constructed such that the elastic net is an extruded elastic net. [00373] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00374] The respirator may be constructed such that it includes a sorbent layer. [00375] The respirator may be constructed such that it includes a cover web layer. [00376] The respirator may be constructed such that it includes: a nose clip, a foam layer, a valve, or a harness. [00377] The respirator may be constructed such that it includes a strap, and the strap, in combination with the layer of wrinkled media, forms a unitary wrinkled media article. [00378] The respirator may be constructed such that the respirator is a horizontal tri-fold respirator. [00379] The respirator may be constructed such that the horizontal tri-fold respirator includes a top panel, a bottom panel and a center panel, and the center panel includes the wrinkled media layer. [00380] The respirator may be constructed such that the horizontal tri-fold respirator includes a top panel, a bottom panel and a center panel, and the bottom panel includes the wrinkled media layer. [00381] The respirator may be constructed such that the horizontal tri-fold respirator includes a top panel, a bottom panel and a center panel, and the top panel includes the wrinkled media layer. [00382] The respirator may be constructed such that the respirator is a vertical fold respirator. [00383] The respirator may be constructed such that the respirator is a duck-bill respirator. [00384] The respirator may be constructed such that the respirator is a cup-shaped respirator. [00385] The respirator may be constructed such that the respirator is a pleated respirator. [00386] The respirator may be constructed such that the respirator includes a shell layer. [00387] The respirator may be constructed such that the respirator includes a sorbent layer. [00388] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter. [00389] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 20% longer than a resting racetrack perimeter. [00390] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 30% longer than a resting racetrack perimeter. [00391] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 40% longer than a resting racetrack perimeter. [00392] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 50% longer than a resting racetrack perimeter. [00393] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 60% longer than a resting racetrack perimeter. [00394] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 70% longer than a resting racetrack perimeter. [00395] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 80% longer than a resting racetrack perimeter. [00396] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 90% longer than a resting racetrack perimeter. [00397] The respirator may be constructed such that a stretched racetrack perimeter of the respirator is 100% longer than a resting racetrack perimeter. [00398] The respirator may be constructed such that one of the first and second nonwoven layers includes a membrane. [00399] The respirator may be constructed such that one of the first and second nonwoven layers includes a fibrous nonwoven material.

Claims

What is claimed is: 1. A horizontal flat-fold respirator comprising: a layer of wrinkled media, wherein the wrinkled media comprises: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous web, wherein the first non-woven porous web is directly bonded to the second non-woven porous web, wherein at least one portion of the wrinkled media is resiliently extensible under tension.

2. The respirator of claim 1, wherein the respirator further comprises: a top panel configured to seal around a nose of a user; a bottom panel configured to seal around a chin of a user; and a center panel, wherein the center panel comprises a top edge and a bottom edge, wherein the center panel seals to the top panel along the top edge, and wherein the center panel seals to the bottom panel along the bottom edge.

3. The respirator of claim 1 or 2, wherein the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and wherein the stretched height is at least 10% longer than the resting height.

4. The respirator of any of claims 1-3, wherein the pressure drop across the respirator filter at 85 LPM air flow rate is less than 6 mmH₂O.

5. The respirator of any of claims 1-4, wherein the respirator has a quality factor greater than 1.6 at a at an air flow rate of 85 LPM.

6. The respirator of any of claims 2-5, wherein the center panel comprises the layer of wrinkled media.

7. The respirator of any of claims 2-6, wherein two of the top panel, bottom panel and center panel comprise the layer of wrinkled media.

8. The respirator of any of claims 2-7, wherein one of the top panel, bottom panel and center panel comprise wrinkled and unwrinkled nonwoven media.

9. The respirator of any of claims 2-8, and further comprising: a shell layer, the shelled layer comprising a resilient material.

10. The respirator of any of claims 1-9, wherein a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter.

11. The respirator of any of claims 1-10, and also comprising a stiffening layer.

12. The respirator of any of claims 2-11, and also comprising a strap, and wherein the strap, in combination with one of the top, bottom or center panel, forms a unitary wrinkled media article.

13. A cup-shape respirator comprising: a layer of wrinkled media, wherein the wrinkled media comprises: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous web, wherein the first non-woven porous fibrous web is directly bonded to the second non- woven porous web, wherein at least one portion of the wrinkled media is resiliently extensible under tension.

14. The respirator of claim 13, wherein the respirator further comprises: a formed portion that, in a first state, comprises curvature in multiple directions.

15. The respirator of any of claims 13-14, wherein the respirator can be stretched from a resting height to a stretched height, and recover to the resting height, and wherein the stretched height is at least 10% longer than the resting height.

16. The respirator of any of claims 13-15, wherein the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O.

17. The respirator of any of claims 13-16, wherein the respirator has a quality factor greater than 1.6 at a at an air flow rate of 85 LPM.

18. The respirator of any of claims 13-17, and further comprising a shell layer.

19. The respirator of any of claims 13-18, wherein the respirator is resilient such that the curvature recovers after a force is applied to the curvature.

20. The respirator of any of claims 13-19, wherein a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter.

21. A vertical fold respirator comprising: a layer of wrinkled media, wherein the wrinkled media comprises: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous fibrous web, wherein the first non-woven porous fibrous web is directly bonded to the second non- woven porous fibrous web, wherein at least one portion of the wrinkled media is resiliently extensible under tension.

22. The respirator of claim 21, wherein the respirator can be stretched from a resting length to a stretched length, and recover to the resting length, and wherein the stretched length is 10% longer than the resting length.

23. The respirator of any of claims 21-22, wherein the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 3.0 mmH2O.

24. The respirator of any of claims 21-23, wherein the respirator has a quality factor greater than 1.6 at an air flow rate of 85 LPM.

25. The respirator of any of claims 21-24, wherein a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter.

26. A duckbill respirator comprising: a layer of wrinkled media, wherein the wrinkled media comprises: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous fibrous web, wherein the first non-woven porous fibrous web is directly bonded to the second non- woven porous fibrous web, wherein at least one portion of the wrinkled media is resiliently extensible under tension.

27. The respirator of claim 26, wherein the respirator is configured to fold flat along a centerline, and wherein the respirator further comprises: a first generally trapezoidal portion configured to contact a nose of a wearer; a second generally trapezoidal portion configured to contact a chin of a wearer; and wherein one of the first and second generally trapezoidal portions comprises the layer of wrinkled media.

28. The respirator of claim 26 or 27, wherein the respirator can be stretched from a resting length to a stretched length, and recover to the resting length, and wherein the stretched length is 10% longer than the resting length.

29. The respirator of any of claims 26-28, wherein the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O.

30. The respirator of any of claims 26-29, wherein the respirator has a quality factor greater than 1.6 at a at an air flow rate of 85 LPM.

31. The respirator of any of claims 26-30, wherein a stretched racetrack perimeter of the respirator is 10% longer than a resting racetrack perimeter.

32. A pleated respirator comprising: a layer of wrinkled media, wherein the wrinkled media comprises: a first series of substantially parallel non-bonded elastic filaments between a first and a second non-woven porous fibrous web, wherein the first non-woven porous fibrous web is directly bonded to the second non- woven porous fibrous web, wherein at least one portion of the wrinkled media is resiliently extensible under tension.

33. The respirator of claim 32, wherein the respirator further comprises a mask body that has a transversely-extending line of demarcation, a longitudinal axis, first and second weld patterns disposed above and not traversing the line of demarcation on each side of the longitudinal axis, respectively, and third and fourth weld patterns disposed below and not crossing the line of demarcation on each side of the longitudinal axis, respectively, wherein each of the first, second, third, and fourth weld patterns is a two-dimensional enclosed pattern.

34. The respirator of any of claims 32-33, wherein the respirator can be stretched from a resting length to a stretched length, and recover to the resting length, and wherein the stretched length is 10% longer than the resting length.

35. The respirator of any of claims 32-34, wherein the pressure drop across the respirator filter, at 85 LPM air flow rate is less than 3.0 mmH2O.

36. A method of making a respirator, the method comprising: obtaining a wrinkled media article; forming a stack of media layers, wherein the wrinkled media article is a wrinkled layer within the stack of media layers; sealing the stack of media layers; and wherein, when sealed, the stack of media layers have a resting racetrack perimeter length, and can resiliently stretch to a stretched racetrack perimeter, and wherein the stretched racetrack perimeter is 10% greater than the resting racetrack perimeter.

37. The method of claim 36, wherein sealing comprises welding, point-welding, bonding, or point-bonding, or forming a seam.

38. The method of any of claims 36-37, wherein the respirator is a horizontal tri-fold respirator, a vertical fold respirator, a cup-shape respirator, a pleated respirator, or a duck-bill respirator.

39. The method of any of claims 36-38, wherein the pressure drop across the respirator filter, at 85 LLPM air flow rate is less than 3.0 mmH₂O.

40. The method of any of claims 36-39, wherein the respirator has a quality factor greater than 1.6 at an air flow rate of 85 LPM.