WO2014007847A1

WO2014007847A1 - Conformable face mask

Info

Publication number: WO2014007847A1
Application number: PCT/US2013/027665
Authority: WO
Inventors: Alexander C. Tsuei
Original assignee: 3M Innovative Properties Company
Priority date: 2012-07-02
Filing date: 2013-02-25
Publication date: 2014-01-09
Also published as: TW201402171A; EP2866902A1; CA2878169A1; KR20150036251A; EP2866902A4; CN104519965A; JP2015527500A; CN107095374A; US20150173436A1; BR112015000124A2

Abstract

A face mask comprising an elastic sheet and a filtering web. The elastic sheet defines inner and outer surfaces, and an elongated shape. The elongated shape forms a central portion. A cut-out is formed through a thickness of the elastic sheet at the central portion. The filtering web forms at least one pleat, and is bonded to the outer surface of the elastic sheet along a bondline. The bondline borders a chamber region at least partially established by the filtering web, with the cut-out being fluidly open to the chamber region. When worn, the inner surface is placed against the user's face, and a mouth and a portion of the nose of the user is inserted through the at least one cut-out. In some embodiments, the filtering web forms two vertical pleats that are located at opposite sides of a centerline of the face mask.

Description

CONFORMABLE FACE MASK

Background

Protective face masks are useful in a number of fields. In the health care field, a face mask may be useful for protecting both the patient and the health care provider from airborne pathogens or for preventing the transfer of pathogens that reside in the bodily fluids or other liquids. Wearing protective face masks may also be useful in many industrial settings.

Many protective face masks are constructed to have a front panel that covers the nose and mouth of a user and a securing device (e.g., manual tie straps) that can attach this front panel securely to the head of the user. Often, the front panel and the tie straps are created separately in separate processes and then attached to one another (e.g., using adhesives, staples, or other mechanical fasteners). Face masks constructed from separate parts that must be joined together suffer from disadvantages. The attachment point between the front panel and the tie strap may be broken, for example, by pulling on the tie strap. Also, the separate manufacturing processes of the separate parts and the subsequent joining steps may result in a process that is relatively costly and time consuming. Additionally, the attachment points may be sites of weakness in the face mask. For example, the attachment of the two parts may result in apertures in the face mask that allow for the transfer of pathogens to or from the wearer of the face mask.

So-called single piece face masks are known. In this type of face mask, the front panel is formed integrally with side panels that otherwise provide openings that are used to attach the face mask to the wearer. The front panel and the side panels may be die cut from a web of material and may be formed at the same time. Some of these masks are stretchable to achieve a better fit on the face of the wearer. However, a stretchable, single piece face mask may not have the filtering efficiencies desired for some applications. Moreover, additional components are often required (e.g., a metal nose piece) to achieve the desired fit with the particular wearer's face. As a point of reference, the nose root (or bridge) can vary widely in shape and size from person-to-person. Many existing surgical face masks require additional medical nose piece components in order to comply with the nose root of the particular wearer.

Reliable face masks and convenient manufacturing processes for making them continue to be desired.

Summary

Some aspects of the present disclosure relate to a face mask comprising an elastic sheet and a filtering web. The elastic sheet defines an inner surface, an outer surface, and an elongated shape. The elongated shape forms a central portion and opposing, first and second lateral end portions extending from opposite sides of the central portion, respectively. An aperture is formed in each of the first and second lateral end portions. Finally, at least one cut-out is formed through a thickness of the elastic sheet at the central portion. The filtering web forms at least one pleat, and is bonded to the outer surface of the elastic sheet along a perimeter bondline. The perimeter bondline borders a chamber region that is at least partially established by the filtering web, with the at least one cut-out being fluidly open to the chamber region. With this construction, the face mask is configured to provide a worn state in which the inner surface is placed against the user's face, and a mouth and a portion of the nose of the user passes through the at least one cut-out. In the worn state, portions of the inner surface of the elastic sheet contact the user's face to create a substantially continuous line of engagement circumscribing the chamber region, effectively sealing the chamber region relative to user's breathing passages, with the pleated filtering web able to expand in shape via the pleat(s) as the user exhales. In some embodiments, the filtering web forms two vertical pleats that are located at opposite sides of a centerline of the face mask. When the face mask is fastened to a user, the two vertical pleats facilitate compliance of the face mask with the user's nose root. In other embodiments, the cut-out is relatively large, and has a teardrop like-shape through which a user's mouth and portion of the nose readily pass. In other embodiments, slits or lines of perforations are utilized as the cut-out. In yet other embodiments, one or more flaps are provided by the face mask that promotes sealing or compliance with the user's facial anatomy. Regardless, a protection chamber for the mouth and nose of the wearer is created.

The term "nonwoven" as used in this disclosure when referring to a sheet or web means having a structure of individual fibers or threads that are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs can be formed from various processes such as meltblowing processes, spunbonding processing, spunlacing processes and bonded carded web processes.

The term "elastic" as used in this disclosure refers to any material, including a film, fiber, nonwoven web or combination thereof, which exhibits recovery from stretching or deformation.

Brief Description of the Drawings

FIG. 1 is a plan view of a face mask in accordance with principles of the present disclosure, which plan view is of the outward- facing side;

FIG. 2 is a wearer- facing side plan view of the face mask of FIG. 1 ;

FIG. 3 is a cross-sectional view of the face mask of FIG. 1 ;

FIG. 4 is a plan view of an elastic sheet portion of the face mask of FIG. 1 ;

FIG. 5A is a plan view of another elastic sheet useful with face masks of the present disclosure; FIG. 5B is a plan view of another elastic sheet useful with face masks of the present disclosure;

FIG. 5C is a plan view of another elastic sheet useful with face masks of the present disclosure;

FIG. 5D is a plan view of another elastic sheet useful with face masks of the present disclosure;

FIG. 6A is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the outward-facing side and illustrating a filtering web configuration;

FIG. 6B is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the outward- facing side and illustrating another filtering web configuration;

FIG. 7A is a cross-sectional view of another face mask in accordance with principles of the present disclosure;

FIG. 7B is a cross-sectional view of another face mask in accordance with principles of the present disclosure;

FIG. 8 A is a perspective view of the face mask of FIG. 5 A in a worn state as fastened to a user;

FIG. 8B is a perspective view of the elastic sheet portion of the face mask of FIG. 8A in the worn state as fastened to a user;

FIG. 8C is a side view of the worn state of FIG. 8A and illustrating the face mask in cross- section;

FIG. 8D is a simplified front view of a user's face and indicating locations of contact between the face masks of the present disclosure and the user's head;

FIG. 9 is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the inward- facing side;

FIG. 10A is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the inward- facing side;

FIG. 1 OB is a plan view of the face mask of FIG. 1 OA and illustrating inward folding of flaps provided with the face mask;

FIG. 1 1 is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the outward-facing side; FIG. 12 is a schematic illustration of an exemplary method of making a face mask in accordance with principles of the present disclosure;

FIG. 13 A is a perspective view of a roll formed from a continuous layered web of the face masks of FIG. 1;

FIG. 13B is a perspective view of another roll formed from a continuous layered web of the face masks of FIG. 1 ;

FIG. 14A is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the inward- facing side;

FIG. 14B is an outward- facing side plan view of the face mask of FIG. 14A;

FIG. 15 is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the outward-facing side; and

FIG. 16 is a plan view of another face mask in accordance with principles of the present disclosure, which plan view is of the inward- facing side.

Detailed Description

One embodiment of a face mask 20 in accordance with principles of the present disclosure is shown in FIGS. 1-3. As a point of reference, FIG. 1 illustrates the face mask 20 in flattened form (i.e., prior to being fastened to a user's head) as viewed from the outwardly-facing side of the face mask 20, whereas FIG. 2 reflects the inwardly-facing or wearer- facing side of the face mask 20. The face mask 20 includes an elastic sheet 22 and a filtering web 24. These and other optional components of the face mask 20 are described in greater detail below. In general terms, however, the elastic sheet 22 is configured for fastening to user in a manner encompassing a mouth and at least a portion of the nose of the wearer. The filtering web 24 is bonded to elastic sheet 22 in a manner establishing a chamber region 26 (FIG. 3). At least one cut-out 28 is formed through a thickness of the elastic sheet 22, and facilitates placement of the wearer's breathing passages within the chamber region 26. In this regard, optional features of the filtering web 24 and/or the elastic sheet 22 promote compliance of the face mask 20 with contours of the user's face, including the nose root, resulting in multiple points of contact between the elastic sheet 22 and the user's face. Once fastened to the user, the filtering web 24 filters air flow to and from the user. Elastic Sheet 22

With additional reference to FIG. 4 (that otherwise illustrates the elastic sheet 22 in isolation), the elastic sheet 22 defines an outer surface 40 (FIGS. 1 and 4) and inner surface 42 (FIG. 2). As implied above, the inner surface 42 is placed against the wearer's face during use of the face mask 20.

The elastic sheet 22 has, in some embodiments, an elongated shape generally defining a central portion 50 and first and second lateral end portions 52, 54 flanking the central portion 50 on opposite sides, respectively. The central portion 50 is configured for wearing over a mouth and at least a portion of a nose of a person, and the first and second lateral end portions 52, 54 are each configured to at least partially extend around opposite sides of a person's face in a manner facilitating engagement with an ear of a person. In the illustrated embodiment, the first lateral end portion 52 can be configured to extend around the left side of a person's face, and the second lateral end portion 54 can be configured to extend around the right side of a person's face. In some embodiments, the first lateral end portion 52 forms an aperture 60 that can be used to engage a person's ear, and the second lateral end portion 54 has an aperture 62 to engage the person's other ear. In other embodiments, punch-out members can be used instead of apertures 60, 62, and the punch-out portion of the punch-out member can be removed to form the corresponding aperture. In yet other embodiments described below, the lateral end portions 52, 54 can be omitted, and other user-engaging features provided.

As a point of reference, a perimeter of the elastic sheet 22 (and thus of the face mask 20) can inherently define an intended orientation for wearing by a user. For example, and with specific reference to FIG. 4, a perimeter P of the elastic sheet 22, and thus of the face mask 20 (FIG. 1), can be viewed as generally defining a lower edge 70, an upper edge 72, and opposing side edges 74, 76. The elongated shape of the elastic sheet 22 defines a transverse direction T and a longitudinal direction L. The transverse direction T is commensurate with the common direction of extension of the lateral end portions 52, 54 from the central portion 50, and the longitudinal direction L is perpendicular to the transverse direction T. In some embodiments, the longitudinal direction L can also be defined as being parallel with a centerline C that bi-sects the central portion 50, with the elastic sheet 22 being symmetrical about the centerline C. In other embodiments, the longitudinal direction L corresponds with a machine direction of the elastic sheet 22 during manufacture of the face mask 20 as described below. With these designations in mind, the lower edge 70 of the perimeter P is collectively defined by the central portion 50 and lateral end portions 52, 54, and can be characterized as continuously extending toward the upper edge 72 in extension from the centerline C toward the corresponding side edge 74, 76 in some embodiments. Conversely, while the upper edge 72 can exhibit a curvature toward the lower edge 70 in extension from the centerline C toward the corresponding side edge 74, 76 along the central portion 50, at least a segment of the upper edge 72 along the corresponding lateral end portion 52, 54 extends away from the lower edge 70 in extension toward the corresponding side edge 74, 76. With this shape, then, a user will readily understand that fastening of the face mask 20 to the wearer's face entails orienting the lower edge 70 in a vicinity of the wearer's chin, and the upper edge 72 in a vicinity of the wear's nose root. Alternatively, the perimeter P can assume a variety of other shapes that may or may not convey a specific worn orientation to a user. In yet other embodiments, the perimeter P can define one or more flaps as described below. Regardless, in the worn state, a viewer or wearer of the face mask 20 will readily perceive or understand the longitudinal direction L to be vertical (i.e., when the wearer is standing upright, the longitudinal direction L identified above will appear vertical relative to ground), and the transverse direction T to be horizontal. Other features of the face mask 20 are described below relative to these so- defined vertical and horizontal directions.

With the desired orientation of the face mask 20 when worn in mind, the cut-out 28 is formed through an entire thickness of the elastic sheet 22 and is located in the central portion 50. With this arrangement, the cut-out 28 is fluidly open to the chamber region 26 (FIG. 3). Further, the cut-out 28 is sized and shaped to permit passage of a wearer's mouth and a portion of the nose there through. For example, with the one embodiment of FIG. 4, the cut-out 28 has an oblong or teardrop-like shape. In addition, the cut-out 28 can be sized and shaped to generally correspond with a person's facial anatomy. For example, the cut-out 28 can be viewed as having a lower region 80 and an upper region 82. While the cut-out 28 is continuous or open throughout the regions 80, 82, the size or shape of the cut-out 28 expands in the transverse direction T in extension from the upper region 82 to the lower region 80. With this but one acceptable construction, the lower region 80 is generally shaped to facilitate placement under or at a wearer's chin, whereas the upper region 82 more readily corresponds with an expected shape of the wearer's nose region (e.g., at or below the nose bridge).

The shape-related features illustrated and described with respect to the cut-out 28 of FIG. 4 are but one acceptable embodiment in accordance with principles of the present disclosure. The cut-out 28 can have a variety shapes conducive to passage of a person's mouth and at least a portion of the person's nose. In other embodiments, the elastic sheet 22 can form a plurality of cut-outs in the central portion 50. For example, FIG. 5A illustrates an alternative elastic sheet 22' defining first and second cut-outs 28a', 28b' in the form of slits. Slits 28a', 28b' are arranged to intersect one another, forming an X shape and generating several flaps 90. When pressed against a person's chin, mouth and/or nose, the flaps 90 separate from one another to permit passage of the wearer's facial anatomy.

In another embodiment, elastic sheet 22" incorporates a plurality of cut-outs 28" as shown in FIG. 5B. The cut-outs 28" take the form of vertically arranged slits. In other, related embodiments, one or more or all of the cut-outs/slits 28" can be arranged in the horizontal direction as shown in 5C.

In yet other embodiments, and as illustrated for elastic sheet 22"' of FIG. 5D, the plurality of cutouts 28" ' are each in the form of a line of perforations. As the elastic sheet 22"' is pressed against a person's face, the lines of perforations 28"' internally tear or break, permitting passage of the wearer's relevant facial anatomy. In other embodiments, one or more or all of the lines of perforations 28"' can extend in a direction other than the vertical direction as shown. Even further, a face mask construction in accordance with principles of the present disclosure can incorporate a combination of one or more of the cut-outs 28-28"' described above.

Returning to FIGS. 1-4, the elastic sheet 22 optionally includes minor holes (not shown) that can be provided over some or an entirety of the elastic sheet 22, including the central portion 50 and/or the lateral end portions 52, 54. While the elastic sheet 22 can be formed of an elastic nonwoven material that typically has some degree of porosity, the optional minor holes can be intentionally imparted to the elastic sheet 22 and can have a diameter in the range from about 0.5 mm to about 1.5 mm. The minor holes may be useful, for example, for increasing at least one of breathability, elongation, or the comfort of the face mask 20. For example, if the face mask 20 is worn in hot and/or humid environment, the minor holes provided in the elastic sheet 22 may allow for the passage of air to improve comfort. The minor holes in the first and second lateral end portions 52, 54 and otherwise spaced away from the central portion 50 can balance the desire for breathability, elongation, or comfort, as well as the desire for good contact of the face mask 20 around the wearer's nose and mouth. Regardless, when provided, the minor holes can be orders of magnitudes smaller than the cut-out 28 and/or do not pass through an entire thickness of the elastic sheet 22. In other embodiments, the minor holes can be omitted.

The elastic sheet 22 can have a color other than white or could have a pattern of multiple colors. In other embodiments, the elastic sheet 22 can be imparted with a graphic. The term "graphic" means any design, shape, pattern or picture that is visible on the face mask 20, and specifically includes text (e.g., including one or more alphanumeric symbol), pictorial images that include one or more pictures, and combinations thereof. Color patterns and/or graphics may provide enjoyment for the wearer, for example, when the wearer is a child.

In some embodiments, the central portion 50 and the first and second lateral end portions 52, 54 are formed from the same material and form a unitary structure. In other words, the central portion 50 and the first and second lateral end portions 52, 54 are not formed as three separate pieces that are subsequently joined together. Rather, the central portion 50 and the first and second lateral end portions 52, 54 form a continuous structure. Thus, while the central portion 50 may not be clearly demarcated in the elastic sheet 22 as a standalone structure, bonding of the filtering web 24 can be viewed as effectively defining a region of the central portion 50. Also, face masks according to and/or made according to the present disclosure typically have a flat (i.e., planar) shape when they are not being worn. The term "flat" means any of the multiple portions are substantially parallel (i.e., within 10, 7.5 or 5 degrees of parallel) to a plane defined by the elastic sheet 22. The term "flat" also means that the face masks disclosed herein typically do not have means (e.g., seals, seams or bonding) to urge the face mask as a whole into a bent or permanently curved or folded position.

The elastic sheet 22 is configured to stretch in one or more directions. In some embodiments, the elastic sheet 22 has elongation of at least 5 (in some embodiments, at least 10, 25, 40, 50, 75, or 100) percent and up to about 150, 200, 250, 300, 350, or 500 percent in at least one direction. The elongation in terms of percent stretch is [(the extended length-the initial length)/the initial length] multiplied by 100. For example, if a material having an initial length of 1 cm can be stretched 0.50 cm, that is to an extended length of 1.50 cm, the material can be said to have an elongation of 50 percent. In some embodiments, the elastic sheet 22 can stretch in both the transverse direction T and the longitudinal direction L. In some embodiments, all of the central portion 50 and lateral end portions 52, 54 can be stretched in one or more directions. The ability of the elastic sheet 22 to stretch in at least one of the transverse T or longitudinal L directions will typically allow for fuller coverage of the wearer's face and provide for more flexibility in accommodating variously sized faces of potential users. In particular, horizontal and vertical stretching in the central portion 50 will typically allow for better fitting on the face.

The elastic sheet 22 also exhibits recovery from stretching. Recovery refers to a contraction of a stretched material upon termination of biasing force following stretching of the material by application of the biasing force. For example, if a material having a relaxed, unbiased length of 1.0 cm is elongated 50 percent by stretching to a length of 1.5 cm and subsequently contracts to a length of 1.1 cm after release of the stretching force, the material would have recovered 80% (0.4 cm) of its elongation. The elastic sheet 22 can have a recovery of, for example, at least 25, 50, 60, 70, 75, or 80 percent.

In some embodiments, different segments of the central portion 50 may have different elongations in the same direction. For example, at the lower and upper edges 70, 72 along the central portion 50, the elongation may be up to 5 (in some embodiments 4, 3, 2, or 1) percent in the transverse direction T, while between the lower and upper edges 70, 72, the elongation may be greater than 5 and up to 15 (in some embodiments 14, 13, 12, 1 1, or 10) percent in the transverse direction T. In other embodiments, at the lower and upper edges 70, 72along the central portion 50, the elongation may be up to 5 (in some embodiments 4, 3, 2, or 1) percent in the longitudinal direction L, while between the lower and upper edges 70, 72, the elongation may be at least 70 (in some embodiments, at least 75, 80, or 85) percent in the transverse direction T. Reduced elongation at the lower and upper edges 70, 72 may be useful, for example, for providing a good seal against the user's face. In some embodiments, the central portion 50 has elongation of less than 10 (in some embodiments, up to 7.5, 5, 2.5, or 2, or 1) percent in the transverse direction T. In some embodiments, the first lateral end portion 52 and the second lateral end portion 54 each have an elongation of at least 15 (in some embodiments, at least 20, 25, 30, 40, 50, 75, or 90 or 100) percent and up to about 500 (in some embodiments, up to 350, 300, 250, or 200) percent in at least one of the longitudinal direction L or transverse direction T. The amount of elongation in the central portion 50 can be controlled, for example, by the choice of materials, the extent of attachment of the filtering web 24 to the central portion 50, and other features provided by the filtering web 24. Limiting the elongation of the central portion 50 may allow for better filtration properties.

Various materials can be employed for the elastic sheet 22. For example, in some constructions, the elastic sheet 22 is an elastic nonwoven web. In some embodiments, the elastic nonwoven web or portion thereof comprises a spunbonded, meltblown, or spunlace nonwoven. The term "spunbonded" refers to small diameter fibers that are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced to fibers. Spunbond fibers are generally continuous and have diameters generally greater than about 7 microns, more particularly, between about 10 and about 20 microns. The term "meltblown" refers to fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g., air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Meltblown fibers are generally microfibers which may be continuous or discontinuous with diameters generally less than 10 microns. Spunlacing uses high-speed jets of water to strike a web to intermingle the fibers of the web. Spunlacing is also known as hydroentangling and can be carried out on fibrous webs made, for example, using carded webs and air- laid webs.

Exemplary useful materials for making the elastic nonwoven web or portion thereof (e.g., sheet) include thermoplastic elastomers such as ABA block copolymers, polyurethane elastomers, polyolefin elastomers (e.g., metallocene polyolefin elastomers), polyamide elastomers, ethylene vinyl acetate elastomers, and polyester elastomers. An ABA block copolymer elastomer generally is one where the A blocks are polystyrenic, and the B blocks are conjugated dienes (e.g., lower alkylene dienes). The A block is generally formed predominantly of substituted (e.g., alkylated) or unsubstituted styrenic moieties (e.g., polystyrene, poly(alphamethylstyrene), or poly(t-butylstyrene)), having an average molecular weight from about 4,000 to 50,000 grams per mole. The B block(s) is generally formed predominantly of conjugated dienes (e.g., isoprene, 1,3 -butadiene, or ethylene -butylene monomers), which may be substituted or unsubstituted, and has an average molecular weight from about 5,000 to 500,000 grams per mole. The A and B blocks may be configured, for example, in linear, radial, or star configurations. An ABA block copolymer may contain multiple A and/or B blocks, which blocks may be made from the same or different monomers. A typical block copolymer is a linear ABA block copolymer, where the A blocks may be the same or different, or a block copolymer having more than three blocks, predominantly terminating with A blocks. Multi-block copolymers may contain, for example, a certain proportion of AB diblock copolymer, which tends to form a more tacky elastomeric film segment. In some embodiments, the elastic nonwoven sheet useful for practicing the present disclosure is made from a variety of useful materials (e.g., polypropylene, polypropylene-polyethylene copolymers, and thermoplastic polyurethanes). In some embodiments, the elastic nonwoven web is made, for example, from multi- component (e.g., bi-component such as core-sheath) fibers. In some embodiments, the elastic nonwoven web is a multi-layer laminate of different materials (e.g., the materials described above) in the layers. For example, the elastic nonwoven web may comprise a layer of meltblown fibers between two layers of spunbonded fibers.

Materials can be selected for the elastic nonwoven portion or sheet, for example, depending on how they feel against the skin. The elastic nonwoven sheet can be made from materials that feel soft against the skin. The elastic nonwoven sheet can also be made from materials that have a rubbery feeling so that they can stay in place.

Several materials useful for making the elastic nonwoven sheet are commercially available, for example, polyolefins from ExxonMobil, Houston, Texas, under the trade designation "VISTAMAXX" and thermoplastic polyurethane elastomers from Huntsman, The Woodlands, Texas, under the trade designation "IROGRAN". In some embodiments, the elastic nonwoven sheet comprises a matrix nonwoven material. In some embodiments, the elastic nonwoven sheet comprises a spunbond nonwoven available from Idemitsu Kosan Co., Ltd., Tokyo, Japan, under the trade designation "STRAFLEX". In other embodiments, the elastic sheet is a bicomponent elastic nonwoven web employing a styrenic block copolymer core material and a sheath material. For example, a bicomponent elastic nonwoven web of styrenic block copolymer core available from Kraton Polymers LLC, Houston, Texas (under the trade designation G1643, MD6705, or MD6717) and a polypropylene sheath. The core:sheath radio can be 85: 15 or 80:20, for example.

Filtering Web 24

The filtering web 24 is bonded to the central portion 50 as described in greater detail below. The term "filtering" with respect to the filtering web 24 described herein refers to separating or removing a portion of the exhalation from the face mask wearer, or a portion of the inhalation encountered by the face mask wearer. The filtering web 24 is typically capable of at least one of providing a barrier to the transmission of pathogenic microorganisms to or from the wearer, trapping allergens (e.g., pollen), trapping particulates, trapping or masking odors, trapping or providing a barrier to liquids, removing cold air (i.e., providing thermal insulation), or reducing viral or bacterial contamination.

As shown in FIGS. 1 and 3, the filtering web 24 forms at least one pleat 100. In some embodiments, the pleat 100 is a flat pleat made, for example, by folding the filtering web 24 material back on itself a first time, and then folding it back on itself a second time as illustrated in FIG. 3, resulting in fold lines 102, 104. Although the pleat 100 shown in FIG. 3 is a single pleat, double pleats or other multiple pleats may also be used with face masks of the present disclosure. For double pleats, the above- described folding pattern is usually repeated twice with the same folding direction. For multiple pleats, this folding pattern is usually repeated multiple times. In flat-pleated material, a majority of the pleated material is substantially parallel (i.e., within 10, 7.5, or 5 degrees of parallel) to a plane defined by the elastic sheet 22. Flat pleats as shown in FIG. 3 are useful for allowing compact stacking or rolling of the face masks disclosed herein. In contrast, if the filtering web 24 is attached to the elastic sheet 22 by stretch bond lamination, the presence of gathers in the filtering web 24 may interfere with compact stacking or rolling of the face masks disclosed herein.

The pleat 100 is arranged in the filtering web 24 such that upon final assembly of the filtering web 24 to the elastic sheet 22, the pleat 100 (or the fold lines 102, 104) extends substantially parallel (i.e., within 10 degrees of parallel) of the longitudinal direction L, and thus can be referred to as a vertical pleat (i.e., when the face mask 20 is worn by a user, the pleat 100 (as defined by a direction of the fold lines 102, 104) has a vertical orientation). While a single vertical pleat 100 is illustrated, in other embodiments, two vertical pleats can be provided. For example, with the alternative face mask 20' of FIGS. 6A, first and second vertical pleats 110, 1 12 are formed by the filtering web 24' and can be located at opposite sides of the centerline C. As described below, with this one acceptable construction, expansion of the vertical pleats 1 10, 1 12 upon application of the face mask 20' to a user's face promotes compliance of the face mask 20' relative to the shape of the user's nose root.

In yet other embodiments, and with reference to FIG. 6B, face masks of the present disclosure can include one or more horizontal pleats 120. In yet other embodiments, the filtering web 24 can include a combination of one or more vertical pleats and one or more horizontal pleats.

Returning to FIGS. 1-3, a variety of materials are useful for making the filtering web 24. In some embodiments, the filtering web 24 is a nonwoven material (e.g., a polypropylene nonwoven material). Alternatively, the filtering web 24 can be a microreplicated perforated film. The filtering web 24 may also include multiple layers of nonwoven materials or microreplicated perforated films. In some embodiments, the filtering web 24 is electrically charged. Charged filtration medium typically increases filtration efficiency by drawing particles to be filtered toward the filter by virtue of their electrical charge. In some embodiments, the filtering web 24 is an electret. Electret treatment can be carried out by a number of techniques (e.g., those described in U.S. Patent Nos. 5,401,446; 4,215,862; 4,375,718; 4,592,815; and 4,874,659, the disclosures of which are incorporated herein by reference in their entirely). In some embodiments, the filtering web 24 has a filtering efficiency of at least 99 (in some embodiments, 98, 97, 96, or 95) percent. In some embodiments, the filtering web 24 is useful, for example, for protecting the face mask wearer from unpleasant odors. In some of these embodiments, the filtering web 24 is loaded with activated carbon or other particles. In related embodiments, the filtering web 24 may include two or more layers of material, for example in the form of a pad. The filtering web 24 may also be a nonwoven web with the particles uniformly dispersed throughout the nonwoven web using conventional techniques. Or the filtering web 24 can be formed with the particles embedded in the nonwoven, for example an activated carbon fiber nonwoven available, for example from Kuraray Chemical Co., Osaka, Japan. In other embodiments, the filtering web 24 is provided with a fragrance (e.g., for masking the unpleasant odors).

In some embodiments, the filtering web 24 or portion thereof is a nonwoven web of microfibers that are thermally insulating. For example, the filtering web 24 may comprise a mixture of microfibers and crimped staple fibers as described in U.S. Patent No. 4,1 18,531, the disclosure of which is incorporated herein by reference in its entirety. In some of these embodiments, the filtering web 24 can include two or more layers of material, for example in the form of a pad.

In yet other embodiments, the filtering web 24 includes an antiviral, antibacterial, or antifungal agent. Suitable agents of this type include citric acid, boric acid, and silver oxide. In some of the embodiments, the filtering web 24 comprises a nonwoven web onto which the antiviral, antibacterial, or antifungal agent is applied (e.g., by rolling or spraying as described, for example, in U.S. Patent No. 4,856,509). The antiviral, antibacterial or antifungal agents may be used for killing airborne pathogens and for pathogens in bodily fluids or other liquids that may come into contact with the face mask.

In yet other embodiments, the filtering web 24 or a portion thereof is microfiber insulation available from 3M Company, St. Paul, Minnesota, under the trade designation "THINSULATE".

In some embodiments, the filtering web 24 or portions thereof provides a barrier to liquids, for example by virtue of having a low-surface-energy coating, on at least one surface, or a low-surface- energy material embedded in the web. The low-surface-energy coating or material can be provided, for example, with a wax, a silicone, or fluorochemical additive. Suitable fluorochemical additives include those described in U.S. Patent Nos. 5,025,052; 5,099,026; 5,706,804; and 6, 127,485. Filtering webs providing a barrier to liquids (i.e., fluid resistance) may be useful, for example, for a surgical mask. While some filtering web constructions can be designed to exhibit multiple functions, face masks according to the present disclosure may include two different filtering web portions, with each filtering web portion having the same or different functionality. For example, the face mask may include both a first filtering web portion that is charged to remove particles and a second filtering web portion that is designed to provide thermal insulation. Combinations of any of the functionalities as described can be employed. To make face masks according to these embodiments, two different filtering web portions with the desired functionality are used, and combine to define the filtering web 24.

Elastic sheet 22/Filtering Web 24 Bonding

Regardless of the materials employed for the elastic sheet 22 and the filtering web 24, the filtering web 24 is bonded, either directly or indirectly, to the outer surface 40 of the elastic sheet 22 along a perimeter bondline 122. As best shown in FIG. 1, the perimeter bondline 122 is continuous, creating a closed border of the chamber region 26. In some embodiments, the perimeter bondline 122 follows the shape and contour of an exterior edge of the filtering web 24, although in other embodiments the perimeter bondline 122 can be offset from the filtering web 24 edge at various locations. Further, the perimeter bondline 122 can extend across and encompass one or both ends of the pleat(s) 100. In some constructions, the perimeter bondline 122 is an ultrasonically- formed bond. Alternatively, other bonding formats are also acceptable such as adhesive, hot melt, thermal, needle punch, etc.

With specific reference to FIG. 3, the perimeter bondline 122 is shown as including a bond directly between the filtering web 24 and the elastic sheet 22 (i.e., the filtering web 24 contacts the outer surface 40 of the elastic sheet 22). In other embodiments, one or more additional layers or materials can be included between the filtering web 24 and the elastic sheet 22. For example, and as shown in FIG. 7A, an alternative face mask 130 in accordance with principles of the present disclosure includes a second web portion 132 bonded to the central portion 50 of the elastic sheet 22. The elastic sheet 22, the filtering web 24, and the second web portion 132 can be arranged in any configuration. In the illustrated embodiment, the second web portion 132 is disposed on the filtering web 24 such that the second web portion 132 is interposed between the elastic sheet 22 and the filtering web 24 (i.e., the filtering web 24 is indirectly bonded to the elastic sheet 22). The second web portion 132 can be a polymeric film or other material selected to provide desired filtering, supporting or other functional features. FIGS. 7B illustrates yet another face mask 140 in accordance with principles of the present disclosure and includes a polymeric film 142 (e.g., a polyolefinic film) laminated to the outer surface 40 of the elastic sheet 22. The filtering web 24 is bonded to the polymeric film 142 (and is thus indirectly bonded to the elastic sheet 22).

Methods of Use

Returning to FIGS. 1-4, during use the face mask 20 is applied and fastened to a wearer's head with the inner surface 42 of the elastic sheet 22 facing the wearer. In particular, the central portion 50 is generally aligned with the wearer's mouth and nose, and the first and second lateral end portions 52, 54 are fastened to the wearer's ears. This arrangement naturally brings the central portion 50 over wearer's mouth and at least a portion of the nose. FIG. 8A illustrates the face mask 20' fastened to a person 150. The upper edge 72 along the central portion 50 generally extends along contours of the wearer's nose root region 152, whereas the lower edge 70 naturally nests under or adjacent the wearer's chin region 154. Commensurate with this arrangement, the wearer's mouth and at least the nostril region of the wearer's nose pass through the cut-out 28 (FIG. 2). As a point of reference, FIG. 8B depicts the elastic sheet 22 of the face mask 20' (i.e., the filtering web 24' (FIG. 6A) is removed from the face mask 20' for ease of explanation) applied or fastened to the wearer 150, and reflects the wearer's mouth 160 and portion of the nose 162 passing through the cut-out 28. As a result, the mouth 160 and nostrils 164 (i.e., the wearer's breathing passages) are fluidly connected with the chamber region 26 as generally illustrated in FIG. 8C. Notably, the mouth 160 and the nostrils 164 are effectively isolated within the chamber region 26 from the user's environment due to conformance of the elastic sheet 22 to the user's face 166 at various locations that effectively generate substantially continuous zones of contact. More particularly, as the elastic sheet 22 is stretched so as to extend between the wearer's ears and under the chin region 154, the elastic sheet 22 is caused to directly contact the wearer's face 166 at various locations or points that collectively create a substantially continuous (e.g., within 10 percent of a truly continuous) line of engagement between the elastic sheet 22 and the user's face 166 that circumscribes the chamber region 26 (and the user's mouth 160 and nostrils 164). The "line" of contact formed between the inner surface 42 of the elastic sheet 22 and the user's face 166 is not necessarily a regular or uniform shape; instead, and as generally indicated in FIG. 8D, a line of contact 170 along the user's face 166 can be achieved at a plethora of different locations due to the anatomical contours of the wearer's face 166. Regardless, and with additional reference to FIG. 8 A, with embodiments in which the face mask 20' includes two of the vertical pleats 1 10, 1 12 at opposite sides of the face mask centerline C (FIG. 4), the vertical pleats 1 10, 1 12 can slightly expand with stretching of the elastic sheet 22, better ensuring that the elastic sheet 22 will conform to and contact the user's face 166 at the nose root region 152 regardless of a particular shape or size of the nose root region 152. More particularly, as the elastic sheet 22 is pulled or stretched toward the user's ears, tension is experienced by the facemask 20' at the nose root region 152; the inwardly- facing fold line of the vertical pleats 110, 1 12 are drawn toward the user's face in response to this tension, conforming to a shape of the nose root region 152. As a point of reference, a rigidity of the nose root region 152 may result in incomplete contact between the elastic sheet 22 and the nose root region 152 and thus an incomplete seal about the chamber region 26.

Once the face mask 20' is applied to the wearer, the pleats 1 10, 1 12 (or any of the other pleat configurations described above) can freely expand as necessary to accommodate contours of the user's face 166, as well as inhaled and exhaled breaths.

Enhanced Contact

Another embodiment face mask 180 in accordance with principles of the present disclosure is shown in FIG. 9 (the inwardly-facing or wearer-facing side being illustrated in FIG. 9). The face mask 180 includes an elastic sheet 182 and a filtering web 184. The elastic sheet 182 can be formed of any of the materials (and exhibit any of the properties) described above, and provides a central portion 186 within which at least one cut-out 188 is formed. The cut-out 188 can assume any of the formats described above and is through a thickness of the elastic sheet 182. The filtering web 184 can also assume any of the forms previously described, and includes one or more pleats (hidden in FIG. 9). A perimeter bondline 190 secures the filtering web 184 to the elastic sheet 182. While the face mask 180 is thus highly akin to the face mask 20, a shape of the perimeter P is modified. In particular, at least one of the elastic sheet 182, the filtering web 184, or both, is cut to define first and second flaps 192, 194 at or extending from an upper edge 196. The flaps 192, 194 can be symmetrically arranged relative to the face mask centerline C as shown, or can have dissimilar shapes. Even further, only one flap, or more than two flaps, can be provided. Regardless, the flaps 192, 194 are foldable relative to the upper edge 196. With this construction, when the face mask 180 is applied to the user's head, the flaps 192, 194 can be manually folded inwardly (toward the user's face) as represented by arrows in FIG. 9. The folded-in flaps 192, 194 will directly contact the user's face to create a better or more complete contact between the face mask 180 and the upper portion of the user's face.

Another embodiment face mask 200 in accordance with principles of the present disclosure is shown in FIG. 10A (the inwardly- facing or wearer- facing side being illustrated in FIG. 10A). The face mask 200 is akin to the face mask 20 (FIGS. 1-3) described above, and includes an elastic sheet 202 and the filtering web 24 (primarily hidden in the view of FIG. 10A). The elastic sheet 202 can have any of the forms described above, and forms a cut-out 204. With the configuration of FIG. 10A, the cut-out 204 includes several cuts through a thickness of the elastic sheet 202 in a central portion 206 that combine to define first and second flaps 208, 210. The flaps 208, 210 are connected to a remainder of the central portion 206 at a corresponding fold line 212, 214, respectively. In other embodiments, only one flap, or more than two of the flaps, can be provided. When the face mask 200 is applied to the user's head, the flaps 208, 210 can be manually folded inwardly (toward the user's face) as shown in FIG. 10B. The folded-in flaps 208, 210 will directly contact the user's face to create enhanced contact between the face mask 200 and a corresponding portion of the user's face.

Another embodiment face mask 220 in accordance with principles of the present disclosure is shown in FIG. 1 1 (the outwardly- facing side being illustrated in FIG. 1 1). The face mask 220 can be highly akin to any of the face masks described above (e.g., the face mask 20 of FIGS. 1-3, the face mask 20' of 6A, etc.), and includes the elastic sheet 22 and the filtering web 24. The elastic sheet 22 can have any of the forms described above, and forms a cut-out (hidden in the view of FIG. 1 1 , but akin, for example, to the cut-out 28 of FIG. 2) as previously described. The filtering web 24 can also have any of the forms described above, and can be formed to define one or more pleats. In addition, the face mask 220 includes a formable nose piece 222. The nose piece 222 can be of a type known in the art, and is optionally a strip of soft metal, pliable dead soft metal or plastic that is capable of being manually adapted or manipulated by the wearer to fit the contour of the wearer's nose. The nose piece 222 can be applied (e.g., adhered, bonded, etc.) to an exterior face of the filtering web 24 (outwardly-facing side) adjacent the upper edge 72 as shown. Alternatively, the nose piece 222 can be maintained between the elastic sheet 22 and the filtering web 24, along the inwardly-facing side of the elastic sheet 22, etc.

Methods of Making

Some methods of making a face mask according to the present disclosure involves bonding a filtering web and optionally a second web to a central lane of an elastic web (e.g., an elastic nonwoven web) to form a layered web, and subsequently stamping a face mask into the layered web. With these optional techniques, a plurality of face mask can be manufactured on a continuous basis, and can be temporarily maintained with one another in roll form. The layered web may be of any size, and the face mask may be stamped therefrom in any number, shape, or size.

A schematic illustration of an embodiment of a method of making a face mask according to the present disclosure is illustrated in FIG. 12, and can be akin to the methods of making described in PCT Publication No. WO 201 1/0109327 A2, the teachings of which are incorporated herein by reference in its entirety. In the illustrated embodiment, a filtering web 230 and an optional second web 232 are together fed into a pleating station 236 where they are provided with a desired pleating configuration. In other embodiments, the optional second web 232 can be fed through a cutting or stamping station prior to merging with the filtering web 230 and at which one or more cut-outs, slits, holes or perforations can be formed. Regardless, an elastic web 234 is continuously fed through a cutting or stamping station 238 at which one or more cut-outs (e.g., the cut-out 28 (FIG. 2)) are formed. The elastic web 234 is then joined to the filtering web 230 (and the optional second web 232) at a bonding station 240 at which an appropriate bonding method (e.g., ultrasonic welding, thermal bonding (e.g., thermal point bonding), adhesive bonding, laminating, stitch bonding, melting bonding, needle punching and hydro- entangling) is performed. After bonding, the joined web is passed through a die cutting station 242 to provide individual face masks 244 which may be packaged as desired at a stacking and packaging station 246. With embodiments including the optional nose piece 222 (FIG. 1 1), the nose piece 222 can be applied (e.g., glued, welded, etc.) to the individual face masks 244 following processing at the die cutting station 242.

For a face mask according to and/or made according to the present disclosure, the first lateral end portion, the second lateral portion, and the central portion of the elastic sheet may all be integrally formed with one another and stamped from the continuous elastic web in one piece. Stamping includes cutting the layered web, for example, with continuous cuts or with discontinuous cuts (e.g., perforations). The cuts (e.g., continuous or discontinuous cuts) may be made, for example, using die cutting (e.g., rotary die cutting) or laser cutting. Referring again to FIG. 2, in some embodiments, the central portion 50, the first lateral end portion 52, and the second lateral end portion 54 can be each stamped with punch-out members that become the cut-out 28, and the apertures 60, 62, respectively. Removal of the punch-out members may be done after the user has obtained the face mask 20, or may be done at a later stage of manufacturing prior to eventual purchase and use by the user. Optional minor holes, as described above, may be formed into a portion of the elastic web 22 simultaneously with the stamping (e.g., die cutting) of the face mask 20. Alternatively, the layered web or elastic web may processed with a microreplicated cutting tool to form minor holes in at least a portion of the web before an elastic web is bonded to the filtering web and the optional second web.

The continuous web manufacturing of the plurality of face masks described above is advantageous in that separate manufacturing steps are reduced or eliminated. Continuous web manufacturing is possible because the central portion 50 and first and second lateral end portions 52, 54 can be formed simultaneously during the stamping process. Furthermore, the configuration of the face mask is such that a filtering web, and elastic nonwoven web, and an optional second web that are continuous in the machine direction may be used.

A plurality of the face masks according to and/or made according to the present disclosure can be formed or provided as a roll of face masks 300 as shown FIGS. 13A and 13B. The roll 300 includes a plurality of face masks 302 formed in a continuous, multilayered web 304 defined by a continuous elastic material web 306 (e.g., the elastic sheet 22 (FIG. 1) described above) and a filtering web 308 (e.g., the filtering web 24 (FIG. 1) described above). In the illustrated embodiments 304, the continuous web comprises the plurality of face masks 302 consecutively positioned in a machine direction, the continuous web 304 having a first longitudinal edge 320 and a second longitudinal edge 322 (as defined, for example, by the elastic web 306). A first lateral end portion 324 (e.g., the first lateral end portion 52 (FIG. 1) described above) of each face mask 302 extends to the first longitudinal edge 320, and a second lateral end portion 326 (e.g., the second lateral end portion 54 (FIG. 1) described above) extends to the second longitudinal edge 322 of the continuous layered web 304. The filtering web 308 is bonded along a central lane 328 of the elastic web 306. In similar embodiments, the filtering web 308 is bonded to the central lane 328 in a manner such that at least a portion of the central lane 328 has reduced elongation in at least one direction relative to the first and second lateral end portions 324, 326. In some embodiments, the central lane 328 has up to 5 (in some embodiments, up to 4, 3, 2, or 1) percent elongation in the machine direction (e.g., the longitudinal direction L in FIG. 4). The elongation the central lane 328 can be controlled, for example, by the choice of materials, the extent of bonding of the filtering web 308, and the number of pleats in the filtering web 308 as described above. In the illustrated embodiment, the roll 300 is formed around a core. In some embodiments, the continuous layered web is formed into a roll without a core, and the face masks can be dispensed from inside the roll, for example, from a dispenser in the general form of a canister. For the continuous layered web according to the present disclosure, the plurality of face masks may be stamped into the continuous web 304 but not removed from the continuous web 304 so that the web may be formed, for example, into a roll or otherwise dispensed from the continuous web 304. The solid lines shown in FIGS. 13A and 13B represent solid cuts, and the remaining web portions not included in the plurality of face masks 302 can be removed. The plurality of face masks may be connected to one another through a perforated connection. The perforations can have a length and spacing as desired for the type of dispenser. For example, the face masks 302 may be connected to each other at just two or three spaced apart points for dispensing the center portion of the roll 300. The face masks 302 on the web 304 may be in an abutting relationship as shown in FIG. 13A, or there may be a space 330 between the face masks 302 as shown in FIG. 13B.

Regardless of whether the plurality of face masks are temporarily maintained in a roll, FIGS. 13A and 13B further reflect that in some embodiments, the elastic web 306 and the filtering web 308 are both typically continuous in the machine direction. The central lane 328 of the continuous elastic web 306 has a cross-web width that is less than the cross-web width of the entire elastic web 306 (i.e., the cross-web width of the central lane 328 is less than the cross-web distance between the longitudinal edges 320, 322). The central lane 328 is not aligned with the first or second longitudinal edges 320, 322 and in some embodiments is centered about a longitudinal centerline of the elastic web 306. The cross-web width of the central lane 328 may be up to about 50 or about 60 percent and is typically at least about 30 or 35 percent of the cross-web width of the elastic web 306. The filtering web 308 typically has a cross-web width that is substantially the same (e.g., within about 10, 7.5, or 5 percent) as the cross-web width of the central lane 328.

Alternative Securement Features

Another embodiment face mask 400 in accordance with principles of the present disclosure is shown in FIG. 14A and 14B (the inwardly facing or wearer- facing side being illustrated in FIG. 14A). The face mask 400 is akin to the face masks described above (e.g., the face mask 20 of FIGS. 1-3), and includes an elastic sheet 402, the filtering web 24, and loops 404, 406. The elastic sheet 402 can be formed of any of the materials, combination of materials, layers etc., described above. With the embodiment of FIGS. 14A and 14B, a shape of the elastic sheet 402 is akin to the central portion associated with several embodiments described above (e.g., the central portion 50 of FIGS. 1-3), and does not form or provide lateral end portions (e.g., the lateral end portions 52, 54 of FIGS. 1-3 are omitted). Stated otherwise, the elastic sheet 402 terminates at opposing side edges 408, 410 and does not provide ear engagement apertures. A cut-out 412 is formed through an entire thickness of the elastic sheet 402, and can have any of the forms described above.

The filtering web 24 can have any of the forms described above, and is assembled to the elastic sheet 402 as previously described. The loops 404, 406 can be strips of conformable material (e.g., elastic straps, fabric, etc.), and are attached to a corresponding one of the side edges 408, 410. For example, the first loop 404 extends between opposing ends 414, 416. The ends 414, 416 are attached (e.g., bonded, welded, mechanically fastened, etc.) to at least one of the elastic sheet 402 and the filtering web 24 at or adjacent the first side edge 408 in a spaced apart fashion. The second loop 406 is similarly attached to at least one of the elastic sheet 402 and the filtering web 24 at or adjacent the second side edge 410. With this construction, the loops 404, 406 are available for engaging a wearer's ears and thus serve as earloops.

A related embodiment face mask 400' is shown in FIG. 15 (the outwardly facing side being illustrated in FIG. 15). The face mask 400' is highly akin to the face mask 400 (FIGS. 14A- 14B), and includes the elastic sheet 402 (hidden in FIG. 15, but shown in FIG. 14A), the filtering web 24, and the loops 404, 406 as described above. With the construction of FIG. 15, however, the loops 404, 406 each extend between the opposing side edges 408, 410. For example, the first end 414 of the first loop 404 is attached (e.g., bonded, welded, mechanically fastened, etc.) to at least one of the elastic sheet 402 and the filtering web 24 at or adjacent the first side edge 408, and the second end 416 is similarly attached at or adjacent the second side edge 410. The second loop 406 is similarly attached to at least one of the elastic sheet 402 and the filtering web 24 at or adjacent the side edges 408, 410 at locations spaced apart from the first loop 404 as shown. The loops 404, 406 are thus available for placement about a wearer's head in securing the face mask 400' to the wearer.

Another embodiment face mask 450 in accordance with principles of the present disclosure is shown in FIG. 16 (the outwardly-facing side being illustrated in FIG. 16). The face mask 450 is highly akin to the face mask 400 (FIGS. 14A-14B) described above, and includes the elastic sheet 402, the filtering web 24, and tie straps 452-458. The first and second tie straps 452, 454 are attached to, and extend in a spaced apart fashion from, at least one of the elastic sheet 402 and the filtering web 24 at or adjacent the first side edge 408. The third and fourth tie straps 456, 458 are attached to, and extend in a spaced apart fashion from, at least one of the elastic sheet 402 and the filtering web 24 at or adjacent the second side edge 410. The tie straps 452-458 can be formed of a soft yet resilient material (e.g., any of the materials described above as being useful for the elastic web 20 (FIG. 1-3)), and can be attached to the elastic sheet 402, the filtering web 24, or both using known techniques (e.g., bonding, welding, mechanical fasteners, etc.). With this construction, the tie straps 452-458 are available for securing the face mask 450 to a wearer's face (e.g., the first and third tie straps 452, 456 are wrapped about opposite sides of the wearer's head and are tied to one another). Face masks, and related methods of use and making thereof, of the present disclosure provide a marked improvement over previous designs. The single piece, elastic sheet in combination with a pleated, outside-facing filtering web advantageously conforms or complies with contours of a wearer's face with a construction that is highly cost effective to manufacture. The cut-out(s) formed in the elastic sheet promote straight forward placement of the wearer's breathing passages with the chamber region of the face mask, with the optional vertical pleats enhancing conformance to a variety differently-shaped nose roots.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present invention.

Claims

What is claimed is:

1. A face mask comprising:

an elastic sheet defining:

an inner surface,

an outer surface,

an elongated shape forming a central portion and opposing first and second lateral end portions extending from opposite sides, respectively, of the central portion, a first aperture in the first lateral end portion,

a second aperture in the second lateral end portion,

at least one cut-out through a thickness of the elastic sheet in the central portion;

a filtering web forming at least one pleat, the filtering web being bonded to the outer surface of the elastic sheet along a perimeter bondline;

wherein a chamber region is at least partially established by the filtering web and is bordered by the perimeter bondline;

and further wherein the at least one cut-out is fluidly open to the chamber region.

2. The face mask of claim 1, wherein the face mask is configured to provide a worn state in which the inner surface is placed against the user's face, and a mouth and at least a portion of a nose of the user are inserted through the at least one cut-out.

3. The face mask of claim 2, wherein the face mask is configured to form a substantially continuous line of contact with a user's face in the worn state that circumscribes the chamber region.

4. The face mask of claim 1, wherein the elongated shape of the elastic sheet in a flattened state defines a transverse direction generally extending between the first and second apertures, and a longitudinal direction perpendicular to the transverse direction, and further wherein the at least one pleat includes a first vertical pleat having a fold line substantially parallel to the longitudinal direction.

5. The face mask of claim 4, wherein the fold line runs continuously from a first location at the perimeter bondline to a second location on the perimeter bondline opposite the first location.

6. The face mask of claim 4, wherein the at least one pleat includes a second vertical pleat having a fold line substantially parallel to the longitudinal direction.

7. The face mask of claim 6, wherein the elongated shape defines a centerline in the longitudinal direction and bi-secting the central portion, and further wherein the first and second vertical pleats are located at opposite sides of the centerline.

8. The face mask of claim 6, wherein the first and second vertical pleats are configured to cause the elastic sheet to comply with contours of a user's nose root region in the worn state.

9. The face mask of claim 1, wherein the elongated shape of the elastic sheet in a flattened state defines a transverse direction generally extending between the first and second apertures, and a longitudinal direction perpendicular to the transverse direction, and further wherein the at least one pleat includes a horizontal pleat having a fold line substantially parallel to the transverse direction.

10. The face mask of claim 9, wherein the at least one pleat includes a second horizontal pleat having a fold line substantially parallel to the transverse direction.

1 1. The face mask of claim 9, wherein the at least one pleat includes a first vertical pleat having a fold line substantially parallel to the longitudinal direction.

12. The face mask of claim 1, wherein the elongated shape of the elastic sheet in a flattened state defines a transverse direction generally extending between the first and second apertures, a longitudinal direction perpendicular to the transverse direction, and a centerline in the vertical longitudinal and bisecting the central portion, and further wherein an edge of the face mask tapers in height from the centerline toward the first and second lateral end portions.

13. The face mask of claim 1, wherein the elastic sheet includes an elastic nonwoven web.

14. The face mask of claim 3, wherein the elastic sheet further includes a polymeric film laminated to the elastic nonwoven web, and further wherein the filtering web is bonded to the polymeric film.

15. The face mask of claim 1, wherein the filtering web includes a filtering layer and a polymeric film layer, and further wherein the polymeric film layer faces the outer surface of the elastic sheet.

16. The face mask of claim 1, wherein the at least one cut-out is an oblong shape.

17. The face mask of claim 1, wherein the at least one cut-out includes a plurality of slits.

18. The face mask of claim 17, wherein the plurality of slits includes first and second slits forming an X shape.

19. The face mask of claim 1, wherein at least one of the elastic sheet and the filtering web forms a flap configured to be folded toward the inner surface and contact a user's face.

20. A method of using a face mask, the method comprising:

receiving a face mask including:

an elastic sheet defining:

an inner surface,

an outer surface,

an elongated shape forming a central portion and opposing first and second lateral end portions extending from opposite sides, respectively, of the central portion,

a first aperture in the first lateral end portion,

a second aperture in the second lateral end portion,

at least one cut-out through a thickness of the elastic sheet in the central portion, a filtering web forming at least one pleat, the filtering web being bonded to the outer surface of the elastic sheet along a perimeter bondline,

wherein a chamber region is at least partially established by the filtering web and is bordered by the perimeter bondline,

and further wherein the at least one cut-out is fluidly open to the chamber region;

fastening the face mask to a user's head, including:

placing the first and second apertures over ears of the user, respectively, inserting a mouth and nose region of the user's head through the cut-out, forming a substantially continuous line of contact between a face of the user and the inner surface, the line of contact circumscribing the chamber region; and

expanding the at least one pleat in response to an exhaled breath of the user.

21. A method of claim 20, wherein the step of fastening the face mask further includes a region of the inner surface conforming to a shape of a user's face in a vicinity of the user's nose root.