The present disclosure relates generally to facemasks and, in particular, to a facemask with a clear see-through portion positioned over the mouth of a wearer during use.
Medical facemasks for use by various health care workers, medical personnel, doctors, surgeons, dentists, and so on are well-known in the art. Such facemasks are designed for filtering unwanted particulates, bacteria, and other contaminants, preferably from both inhaled and exhaled air. Such facemasks typically comprise a porous filtering media and may be a multi-layered structure. For example, the air-porous filtering media may include an outer layer of a nonwoven, spunbond material, and an inner, face-side, layer of a nonwoven cellulose or other material that is appropriate for contact with a wearer's face. The air-filtering media protecting the wearer from contaminates may further include intermediate layers which may be electrostatically charged, and/or may contain various antibacterial and/or antiviral agents and the like.
To protect the wearer from inhaling any form of contaminates, including those that may originate from patients or others, inhaled air flow to the mouth and nose must be adequately filtered through the air-permeable filtering media. This has conventionally been achieved by constructing face masks such that the air-permeable filtering media overlies the wearer's nose and mouth. In addition, to avoid unfiltered air from bypassing the air-permeable filtering media, such face masks typically employ a tight seal between the face of a wearer and the periphery of the facemask.
This construction, while achieving the desired air-filtering function, undesirably hinders the ability of patients and other medical personnel to effectively communicate with the wearer of the conventional face mask. The mouth is hidden behind the filtering media and is not visible to others. Facial expressions and lip movements of the wearer, therefore, cannot be seen. This is particularly problematic if the wearer is trying to communicate with a hearing impaired person.
While some attempts have been made to remedy this deficiency in medical face mask construction, they have been largely unsuccessful, primarily due to the difficulty and high cost of manufacturing such face masks. In addition, most masks of the prior art that include a clear portion are of a rigid construction, provide inadequate face fit, and cannot be conveniently folded flat for storage and ease in dispensing.
Accordingly, there is a need for an air-filtering face mask that provides visibility of the wearer's mouth in order to facilitate communication of the wearer with others, and which is suitable for use by medical, dental, surgical, and other healthcare personnel.
Features of the disclosure will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of this disclosure.
The present disclosure is directed to an air-filtering facemask that provides visibility of the wearer's mouth in order to facilitate communication of the wearer with others, and which is suitable for use by medical, dental, surgical, and other healthcare personnel.
In one aspect, the facemask of the present disclosure includes an air-filtering portion comprising an air-permeable filtering media; a see-through portion positioned and configured so that, in use, a mouth of a wearer is visible therethrough, wherein the see-through portion is formed from a transparent film covering a void in the air-permeable filtering media; and a layered portion on each opposing side of the see-through portion. The layered portion is formed from the transparent film extending across a length of the facemask, so that the film covers the void to form the see-through portion and is also layered on the air-permeable filtering media on each opposing side of the void. The transparent film is fixed along its periphery to the air-permeable filtering media.
1) In one aspect, each of the see-through portion and the transparent film has a vertical width that is greatest at a vertical midline of the facemask.
In further aspects, the transparent film is fixed at its outer side edges along each vertical peripheral edge of the facemask.
The transparent film is fixed, in aspects, to the air-permeable filtering media by one of ultrasonic welding, gluing, sewing, stapling, and combined heat and pressure.
In another aspect, the facemask includes an air-inhibiting seal along a periphery of the facemask.
The air-permeable filtering media in the layered portion, in aspects, includes a high-loft filtering material.
In additional aspects, the transparent film is formed from one or more of a polyester, polyethylene, polypropylene, polycarbonate, or plastic material.
In still further aspects, the air-filtering portion further comprises pleats formed in an upper and lower portion of the air-permeable filtering media. The lower portion is positioned below the transparent film. The pleats (in the lower portion) are configured to expand the mask vertically downward for fitting under the chin of a wearer and vertically upward (in the upper portion) for fitting over the nose and face.
The area of the air-permeable filtering media that forms the pleats in the lower portion of the air-filtering portion, in some aspects, is greater than an area of the see-through portion. The pleats in the facemask may be further configured such that the facemask may be folded flat.
The present disclosure is also directed to a method of manufacture of the facemask, including removing, e.g., by kiss-cutting, the air-permeable filtering media away to form the see-through portion, after layering and, in aspects, after fixing the film to the filtering media.
In one aspect, a method for manufacturing a facemask that includes a see-through portion and air-permeable filtering media, includes layering a transparent film onto a horizontal section of air-permeable filtering media configured to form a facemask; fixing at least a top and bottom peripheral edge of the transparent film to the horizontal section; and removing, after the layering step, the air-permeable filtering media from a portion of the horizontal section positioned to form a see-through portion of the facemask so that, in use, a mouth of a wearer is visible therethrough. The see-through portion is devoid of the air-permeable filtering media and covered by the transparent film. The method also includes sealing a periphery of the air-permeable filtering media forming the facemask. The periphery is configured to abut a wearer's face in use.
In additional aspects, layering the transparent film includes extending the transparent film across a length of the facemask to form the see-through portion and layered portions along either side of the see-through portion. Each of the layered portions includes the transparent film layered on the air-permeable filtering media.
In aspects, sealing the periphery includes fixing the transparent film to the horizontal section along each peripheral side edge of the facemask.
The removing step, in other aspects, includes kiss-cutting the filtering media out of the horizontal section and leaving the transparent film intact to form the see-through portion.
In further aspects, the method further includes shaping the top and bottom peripheral edge of the transparent film with a continuous zig-zag cut before the layering step. The zig-zag cut shapes the transparent film into a diamond-like shape for layering onto the horizontal section of air-permeable filtering media.
In additional aspects the method includes configuring pleats in the air-permeable filtering media above and below the horizontal section.
Each of the fixing and sealing step, in aspects, includes one of ultrasonic welding, gluing, sewing, stapling, and applying combined heat and pressure.
The present disclosure is also directed to a method for manufacturing a facemask, the facemask comprising an air-filtering portion including air-permeable filtering media and a see-through portion, which includes providing a first roll of air-permeable filtering media configured to form a facemask, and providing a second roll of transparent film. The method further includes layering the transparent film as it is fed from the second roll onto a section of the air-permeable filtering media as it is fed from the first roll; and fixing peripheral top and bottom edges of the transparent film to the section of the air-permeable filtering media. After the fixing step, for each length of the air-permeable media fed from the first roll that corresponds to a length of the facemask, air-permeable filtering media is removed from a portion of the section to form a see-through portion of the facemask that is positioned so that, in use, a mouth of a wearer is visible therethrough. The see-through portion of the facemask is devoid of air-permeable filtering media and covered by the transparent film.
In additional aspects, the method further includes configuring pleats, after the removing step, in the air-permeable filtering media positioned above and below the see-through portion of the facemask.
In aspects, the method further includes shaping the top and bottom peripheral edges of the transparent film with a continuous zig-zag cut before the layering step, the zig-zag cut shaping the transparent film fed from the second roll into a diamond-like shape for layering onto the length of the air-permeable filtering media, which is fed from the first roll, corresponding to the length of the facemask.
In further aspects, the method further includes sealing a periphery of the air-permeable filtering media forming the facemask, and separating the facemask from the first roll and the second roll.
The sealing step, in aspects, further includes fixing, as well as sealing, the transparent film to the air-filtering media along peripheral side edges of the facemask.
The present disclosure is also directed to a facemask including an air-filtering portion comprising an air-permeable filtering media; a see-through portion positioned and configured so that, in use, a mouth of a wearer is visible therethrough, wherein the see-through portion is formed from a transparent film covering a void in the air-permeable filtering media; and a layered portion on each opposing side of the see-through portion, the layered portion comprising the transparent film layered on the air-permeable filtering media, the transparent film extending across a length of the facemask to form the see-through portion and the layered portion on each opposing side thereof. The transparent film is fixed along its periphery to the air-permeable filtering media. The air-filtering portion further includes pleats formed in an upper and lower portion of the air-permeable filtering media positioned above and below the transparent film, respectively, the pleats being configured to expand the mask vertically downward for fitting under the chin of a wearer and vertically upward for fitting over the nose and face. The area of the air-permeable filtering media that forms the pleats in the lower portion of the air-filtering portion is greater than an area of the see-through portion.
In addition to the above aspects of the present disclosure, additional aspects, objects, features and advantages will be apparent from the embodiments presented in the following description and in connection with the accompanying drawings.
The drawings constitute a part of this disclosure and include examples, which may be implemented in various forms. It is to be understood that in some instances, various aspects of the disclosure may be shown exaggerated or enlarged to facilitate understanding. The teaching of the disclosure can be readily understood by considering the detailed description in conjunction with the accompanying drawings, which are briefly described below.
The various aspects of the present disclosure mentioned above are described in further detail with reference to the aforementioned figures and the following detailed description of exemplary embodiments.
Particular illustrative embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. It should be apparent to those skilled in the art that the described embodiments provided herein are illustrative only and not limiting, having been presented by way of example only. All features disclosed in this description may be replaced by alternative features serving the same or similar purpose, unless expressly stated otherwise. Therefore, numerous other embodiments of the modifications thereof are contemplated as falling within the scope of the present disclosure of a medical facemask as defined herein and equivalents thereto. Well-known functions or constructions and repetitive matter are not described in detail to avoid obscuring the present disclosure in unnecessary or redundant detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting. In this description, as well as in the drawings, like-referenced numbers represent elements which may perform the same, similar, or equivalent functions.
Throughout the description, where items are described as having, including, or comprising one or more specific components or features, or where methods are described as having, including, or comprising one or more specific steps, it is contemplated that, additionally, there are items of the present disclosure that consist essentially of, or consist of, the one or more recited components or features, and that there are methods according to the present disclosure that consist essentially of, or consist of, the one or more recited processing steps.
The present disclosure is directed to an air-filtering face mask that provides visibility of the wearer's mouth in order to facilitate communication of the wearer with others, and which is suitable for use by medical, surgical, dental, healthcare personnel and others. The present disclosure is also directed to methods for manufacturing the air-filtering face mask of the present disclosure.
The term “kiss-cutting” is used herein, as commonly known, to describe cutting an exposed layer or material without penetrating underlying layers or material. Kiss-cutting can be accomplished using any suitable methods known in the art, including, but not limited to, laser-cutting, or die-cutting (using, e.g., a rotary, blanking, or clicking die) to kiss-cut a portion of the contacted exposed layer(s) without disturbing the underlying material.
Referring to
The facemask 10 further includes a see-through portion 14 that is devoid of the air-permeable filtering media, the void 15 being properly positioned and sized to provide visibility of a mouth of a wearer for improved communications with others. The see-through portion 14 is formed of a portion of the transparent film 16 that covers the void 15. The transparent film 16 is fixed at its periphery to the surrounding air-permeable filtering media. The transparent film 16 covering the void 15 provides both visibility of the wearer's mouth and an air-impermeable barrier to the flow of breathable air therethrough, thereby redirecting breathable air through the air-filtering portions 12 of the facemask 10.
The construction of the facemask of the present disclosure promotes a breathable air path for inhaled and exhaled air through air-filtering portions 12, while providing the see-through portion 14 over a wearer's mouth for enhanced communications. Because the transparent film 16 provides an air-impermeable barrier in front of a wearer's mouth, breathable air is directed (inhaled and exhaled) in an upward and downward path through air-filtering portions 12 to remove any air-borne contaminants.
Air-filtering portions 12 may include at least a single pleat in each of an upper section 18 and in a lower section 20 of the air-permeable filtering material or media to allow the facemask to be expanded vertically for fitting over the nose of a wearer, and under the chin of the wearer, respectively, for an improved face fit.
A bendable nose strip 21 may also be provided in the upper section 18 to conform and seal the mask over a nose and upper facial contours of a wearer.
Additional pleats are preferably provided, particularly in the lower section 20, to provide additional air-filtering media for improved breathability and filtration. In embodiments, the air-permeable filtering material that is added to form the additional pleats of the lower section 20 is in an amount (in square inches, e.g.) of at least equal to, and preferably greater than, the area of the see-through portion 14, and preferably greater than the entire area of the transparent film 16 layered on the air-permeable filtering material. The added air-permeable filtering material essentially replaces that which is lost, compared to a conventional facemask, due to the removal of air-permeable filtering material for forming the see-through portion, and alleviates one of the problems that the addition of a see-through portion presents: reduction in breathability. By increasing the amount of air-permeable filtering material in the lower section 20, the differential pressure across the facemask is lowered, thereby increasing the breathability of the mask and the comfort of the user. The added material, and additional pleats, in the lower section may also help to position the see-through portion with respect to the wearer's mouth. In addition, the added area of the filtering material enhances the filtration properties of the mask.
In embodiments, the amount of filtering material in the entire mask is greater than that provided in a conventional facemask (which has no see-through portion). Typically, such conventional masks, measured in an open position, or before any pleating of the air-permeable filtering media, measure about 7 inches in length (ear-to-ear) and about 7½ inches wide (vertical width). In embodiments of the facemask of the present disclosure, measured in the open position, or before pleating, and before forming the void in the filtering material for the see-through portion 14, the body 2 of air-permeable filtering material measures about 7 inches in length and at least about 8½ inches to about 9½ inches wide. This added material more than compensates for the area occupied by the transparent film, which is, in embodiments, between about 1¼ inches and about 2 inches high at its greatest width (preferably, along vertical midline 34), and preferably tapers down to about ½ inch at the outer edges of the facemask.
In addition, as further described below, there is additional filtering material that is left intact and layered on the transparent film along opposing sides 24 of the central see-through portion 14 after forming the void 15. The air-permeable filtering media in the layered portions 26 rest against the wearer's face in use, reducing and, in embodiments, eliminating contact of the transparent film 16 with the wearer's face during use. Accordingly, in addition to enhancing breathability and filtration, the added filtering material in the layered portions 26 enhances the comfort of the wearer, and also reduces, and preferably eliminates, buildup of condensation on the transparent film 16 due to contact with the skin.
The transparent film 16 may be formed of any suitable transparent or semi-transparent material. In embodiments, the film 16 is a thin, flexible, single film, and can be easily attached by sewing, gluing, or welding, for example, to create a seal between the film 16 and the surrounding air-permeable filtering media without the need for any added sealing structures. As shown in
As best shown in
In embodiments, the transparent film 16 is secured along its periphery, for example, along a bottom peripheral edge 28, a top peripheral edge 30, and along its peripheral side edges 31, to the air-permeable filtering media. In embodiments, the transparent film 16 is secured only along its periphery, leaving the remaining air-permeable filtering media (i.e., excluding the peripheral edges 32) in the layered portions 26 unattached to the transparent film 16.
Referring further to
In further embodiments, the air-permeable filtering media in layered portions 26 may be configured of a high loft, compressible, air-permeable filtering media, such that if the peripheral seal provided along the side edges 32 of the layered portions 26 is breached, breathable air is filtered therethrough. Providing air-permeable filtering media in this high loft, compressible form, may prevent contaminated air that enters through gaps that occur in the peripheral seal 4 from reaching the user by compressing and expanding to conform to the contours of a wearer's face, particularly while the wearer is speaking and causing movement of the facial contours, thereby filtering breathable air, which may be contaminated, through the air-permeable filtering media in the layered portions 26 as well as through the air-filtering portions 12 before it reaches the wearer.
As best shown in
The transparent film 16 may be fixed or bonded to the air-permeable filtering media by any appropriate means known in the art, such as by the use of adhesives, heat and pressure, ultrasonics, and so on.
In embodiments, the transparent film 16 extends to the side edges of the facemask so that the peripheral side edges 31 of the transparent film 16 are coincident with the side edges 32 of the facemask. In this configuration, the peripheral side edges of the transparent film 16 can advantageously be fixed to the facemask in the same step of sealing the periphery of the facemask, as described further herein.
The transparent film 16 is preferably constructed of a single layer of a thin, flexible, plastic sheet of material, which may also be an antifog and/or antiglare material, or optionally, the thin plastic sheet may be coated with an antifog and/or antiglare layer of film. In embodiments, the film 16 may be formed of one or more of a polyester, polyethylene, polypropylene, polycarbonate, or plastic material.
As shown in
Suitable visibility of the mouth of a wearer to enhance communication with others is provided by proper sizing and juxtaposition of the see-through portion 14 relative to the other structural components of the facemask. In the embodiments shown, the see-through portion 14 is in the shape of an oval. However, any appropriate shape is contemplated to be within the scope of the disclosure.
In embodiments, see-through portion 14 is centrally located (in lengthwise, i.e., ear-to-ear direction) and extends across at least 50% of the length (ear-to-ear) of the body 2 of the facemask 10.
In additional embodiments, the see-through portion 14 extends across at least 60% of the length of the body 2 of the facemask 10, preferably extending across about 65% to about 75% of the length of the body 2 of the facemask 10. In still additional embodiments, the see-through portion 14 extends across about 70% of the length of the body 2 of the facemask 10.
In embodiments, the see-through portion 14 may extend vertically over at least about 15% of the height (also referred to herein as width) of the body 2 of the air-permeable filtering material before pleating. In other embodiments, the see-through portion 14 may extend vertically over between about 15% and about 20% of the height of the body 2 of the air-permeable filtering material before pleating.
) The air-permeable filtering media may include any suitable material for use in a facemask to filter air-borne contaminants, and may include one or more nonwoven melt-blown and/or spunbond materials. In embodiments, the media may include one or more layers of material for filtering and/or absorbing unwanted particulates, bacteria, and other contaminants. In embodiments, the air-permeable filtering media may include an outer layer of a nonwoven, spunbond material, and an inner, face-side, layer of a nonwoven cellulose or other material that is more comfortable for contact with a wearer's face. Any number of intermediate layers may also be included.
The facemask of the present disclosure is well-suited for manufacturing in a cost-effective and efficient manner. Referring to
At 104, at least top 30 and bottom peripheral edges 28 of the transparent film 16 are fixed to the horizontal section 22. The fixing step 104, in preferred embodiments, is performed prior to the removing step 108 to prevent slippage of the layers of air-permeable filtering media relative to the transparent film 16. In fixing step 104, the film 16 may be fixed to the air-permeable filtering media, for example, but without limitation, using one of ultrasonic welding, gluing, sewing, stapling, and applying combined heat and pressure.
The body 2 of the air-permeable filtering media is configured to form the facemask of the present disclosure having suitable dimensions and construction for covering a nose, mouth, face, and chin of a wearer. In embodiments, the body 2 of the air-permeable filtering media is configured with pleats, at 106, above 18 and below 20 the horizontal section 22. In embodiments, the pleats are configured at 106 after the removing step at 108.
As described herein, the amount of air-permeable filtering media, preferably configured with pleats, more than compensates for the area occupied by the see-through portion 14, and, in embodiments, more than compensates for the entire area covered by the transparent film. The pleated configuration of the body 2 and the single transparent film construction are also configured to provide a facemask that may be folded flat for storage, as shown in
In some embodiments, the air-filtering media is not configured with pleating, and the periphery of the mask is sealed at 110 without pleating the filtering media.
In other embodiments pleating of the facemask at 106 is performed before removing the air-permeable filtering media at 108. At 110, the periphery of the facemask is sealed.
In one embodiment, the method includes the ordered steps of first layering 102, then fixing 104, then next removing 108, and then, after the removing 108 step, configuring the media with pleats at 106, and finally, sealing the periphery of the facemask at 110.
In other embodiments, the pleats may be configured at 106 before the removing step at 108. One of skill in the art will appreciate that this ordering of steps (pleating 106 before the removing step at 108) is more easily performed in embodiments in which the see-through portion 14 is dimensioned and positioned such that it is entirely located between the folded edges of the pleats. In the embodiment of the mask shown in
Referring again to
Any suitable shape may be cut out of the air-permeable filtering media to form the see-through portion 14 of the present disclosure. In embodiments described herein, though not limited thereto, the void 15 cut in the horizontal section 22 may be in the shape of an oval. In other embodiments, it may be rectangular, or of any other suitable polygonal or other shape that is preferably of a horizontal length across the mask that is greater than its vertical width and that provides adequate visibility of the wearer's mouth.
The layering step 102, in embodiments, further includes extending the transparent film 16 across a length (along direction ear-to-ear) of the facemask, so that the layered portions 26 are formed along either side of the see-through portion 14, each of the layered portions comprising the transparent film 16 layered on air-permeable filtering media.
Referring to
In various embodiments, the step of sealing the periphery of the facemask may include, without limitation, one or more of ultrasonic welding, gluing, sewing, stapling, and applying combined heat and pressure. The step of fixing, at 104, the peripheral edges of the transparent film 16 to the air-permeable filtering media may also include, without limitation, any one or more of ultrasonic welding, gluing, sewing, stapling, and applying combined heat and pressure. The fixing step 104 for fixing the transparent film 16 to the air-permeable filtering media along its edges, like the sealing step at 110 for sealing the periphery of the facemask, preferably creates a substantially air-tight seal between the materials.
Embodiments of the method may also include adding elastic to the periphery, as part of the sealing step 110 or as an additional step, to enhance the peripheral seal 4, by any method known in the art. The elasticizing of the seal may enhance the fit and provide an elasticized air-tight seal for abutting the face of a wearer during use.
In further embodiments, the method includes, at 112, shaping the top 30 and bottom peripheral edge 28 of the transparent film with a patterned cut, e.g., a zig-zag cut, before the layering step, at 102. For example, the zig-zag cut can be configured to shape the transparent film 16 into a diamond-like shape, like the embodiment shown in
In other embodiments, the transparent film may be cut along the top and bottom edges to form any suitable shape and size for layering onto the horizontal section of air-permeable filtering media to form the see-through portion 14.
Although the removing step 108 is performed after the layering step 102 in the present disclosure, and, in embodiments, after the fixing step 104, in various embodiments, other steps may be performed in various orders. In embodiments, some of the steps may be performed concurrently. For example, the peripheral edges of the transparent film may be fixed, at 104, to the air-permeable filtering media concurrently with the layering step, at 102.
Referring to
As shown, the sheet of transparent film that is fed from the second roll 56 may be shaped, at 130, before the layering step 126. In the embodiment shown in
After the layering 126, and preferably the fixing step 128 are applied, a portion 14 of the section 22 that is positioned so that, in use, a mouth of a wearer is visible therethrough, is removed, at 132, for each length 43 of the air-permeable media corresponding to the (unfinished) length 46 of a facemask (see
In embodiments, the removing step 132 includes, at 134, kiss-cutting the filtering media away from the air-permeable filtering media side (back side 52, for example) of the layer of film/filtering media using any appropriate cutting device 74 known in the art, such as a rotary die, blanking die, laser-cutting device, and so on. As shown in
In embodiments, the method 120 may further include configuring portions of the air-permeable filtering media with pleats, at 136. Referring to the embodiment shown in
In other embodiments, portions of the air-permeable filtering media 58 may be pleated at 136 before the removing step at 132. For embodiments of a facemask in which the see-through portion 14 is entirely located between the folded edges of the pleats, for example, embodiments of the method that include pleating 136 before the removing step 132 may be accomplished with the pleating device 76 positioned before (upstream of) the cutting device 74.
In other embodiments, the air-permeable filtering media 58 fed from the roll 54 may be already configured with pleats, so that the pleating step 136 is performed before the layering, fixing and removing steps.
Referring still to
The sealing step 138 may include sealing the top and bottom edges of the pleated media in continuous fashion and also includes sealing along each of the edges perpendicular to the direction in which the rolls are fed (in the direction of width 40) to form the peripheral side edges 32 (separated by the length of each facemask) of the facemasks. As shown in the finished masks of
Referring to
In various embodiments, any of the sealing and fixing steps can be performed by any one or more of, but is not limited to, ultrasonic welding, gluing, sewing, stapling, and applying combined beat and pressure.
The methods of the present disclosure can further include attaching members 6, such as earloops, to the facemask in accordance with any suitable method known in the art.
It should be noted that, although the method of the present disclosure includes performing the removing step 132 after the layering step 126, in embodiments, other steps do not need to be performed in any particular order. Certain steps of the present disclosure may also be performed concurrently.
While particular embodiments of the present disclosure have been particularly shown and described with reference to specific embodiments, it should be apparent to those skilled in the art that the foregoing is illustrative only and not limiting, having been presented by way of example only. It is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms and detail without departing from the spirit and scope of the disclosure. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting. Numerous other embodiments of the facemask of the present disclosure may fall within the scope of the accompanying claims and equivalents thereto.
The present disclosure claims priority to pending U.S. Provisional Patent Ser. No. 62/359,449, filed on Jul. 7, 2016, entitled MEDICAL FACE MASK WITH CLEAR PORTION, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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62359449 | Jul 2016 | US |