GB2596280A

GB2596280A - Face mask

Info

Publication number: GB2596280A
Application number: GB2008541.1A
Authority: GB
Inventors: Maddison Fox Stewart; Stephen Hyams Geoffrey
Original assignee: Rhipsalis Ltd
Current assignee: Rhipsalis Ltd
Priority date: 2020-06-05
Filing date: 2020-06-05
Publication date: 2021-12-29
Anticipated expiration: 2040-06-05
Also published as: GB202008541D0; GB2596280B

Abstract

A face mask 1 comprising a filter material 3 and a plurality of windows 2 in a mouth region of the mask. The windows might be any combination of adjacent to the filter, bordered on edges thereof, or surrounded thereby. The mask may be formed of a layer of filter and a layer of transparent material, each containing a plurality of apertures, where the apertures of the two materials do not overlap. The windows might be in the form of strips, rectangles, hexagons, ovals and/or circles. The ratio between the area of windows and the area of filter material may vary across the mask, in particular to have a higher proportion of windows around the mouth area; this might be achieved by changing the size or density of the windows across the mask. Such a mask allows lipreading but avoids the large impermeable area of a single mask window as seen in the prior art. Also claimed is a laminate which would form the body of such a mask.

Description

FACE MASK

The present invention relates to a face mask, in particular to a face mask which allows the mouth of a wearer to be seen.

Face masks are an important item of personal protective equipment (PPE) in a variety of settings. For example, in hospitals and care homes where controlling the spread of disease is particularly important, the use of face masks can help to protect not only the wearer but also those individuals with whom the wearer comes into contact.

One significant disadvantage of many of the face masks in current use is that the mouth of the wearer is not visible to other people. This can cause communication problems and depersonalises interactions between a wearer of the mask and a patient. This can result in errors being made due to miscommunicated information and can cause patient anxiety.

Whilst various transparent masks are known which seek to solve this problem, they are not without their own problems.

US 4,323,063 describes a mask with a single central transparent portion, where the transparent portion is impermeable to air and the surrounding region is made of air-permeable material that filters the air. However, the large region of impermeable material in the region in front of the mouth means that the surface area of the mask available for air filtration is greatly reduced. This means that either the mask feels uncomfortable to wear, due to the effort required to breathe in and out through the reduced filter area or, more likely, there is greater air leakage between the mask and the face, negating the purpose of the mask.

W02008109438 overcomes this by providing a perforated transparent portion of the mask, allowing greater air flow in the region in front of the mouth. However, the perforations in the transparent material are too large to prevent the transmission of air-borne micro-organisms, such as viruses and bacteria.

It is, therefore, an object of the present invention to seek to alleviate the above identified problems.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided a face mask for filtering airborne particles, the face mask comprising filter material and a plurality of windows, wherein the plurality of windows are in a mouth region of the mask.

Preferably, the windows are adjacent to the filter material.

Within this specification, reference to a window means a region of the face mask which can be seen through. For example, in the context of the present invention, it is possible to see part of a person's face through a window when the person is wearing a mask of the present invention.

Preferably, the windows are impermeable to air.

Preferably, the windows are bordered by filter material on at least two edges thereof.

Preferably, the windows are bordered by filter material on at least two opposing edges thereof.

Preferably, the windows are surrounded by filter material.

Preferably, the windows comprise a transparent material, preferably an air-impermeable transparent material.

Within this specification, reference to a transparent material means a material which can be seen through. For example, in the context of the present invention, it is possible to see part of a person's face through a transparent material.

Preferably, the windows are bonded to the filter material.

Preferably, the windows are bonded to the filter material by heat bonding, ultrasonic welding, laser bonding, solvent bonding or gluing.

Preferably, the windows are heat-bonded to the filter material.

Preferably, the windows are bonded to the filter material by laser bonding or ultrasonic welding.

Preferably, the windows comprise a transparent polymer material.

Preferably, the transparent material is selected from polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polycarbonate (PC), nylon or polyvinylidene chloride (PVDC).

Preferably, the thickness of the windows is between about 0.01mm and about lmm.

Preferably, the filter material comprises an electret.

Preferably, the filter material comprises a non-woven fibrous material.

Preferably, the filter material comprises a laminate, preferably a laminate of spun-bonded and melt-bonded non-woven material.

Preferably, the filter material comprises polypropylene (PP), polyethylene terephthalate (PET) or a fluoropolymer.

Preferably, the filter material is at least an N-95 filter material, for example comprising interlaced layers of polypropylene fibres.

Preferably, the filter material is at least an N-96 filter material, preferably at least an N-97 filter material, preferably at least an N-98 filter material, most preferably an N-99 filter material.

Preferably, the filter material is selected from an N-95 filter material, an N-96 filter material, an N-97 filter material, an N-98 filter material, or an N-99 filter material.

An N-95 filter material is a material which filters at least 95% of airborne particles and meets the U.S. National Institute for Occupational Safety and Health (NIOSH) N95 classification of air filtration. As such, it will be appreciated that N-96, N-97, N-98 and N-99 filter materials filter at least 96%, 97%, 98% and 99% respectively of airborne particles.

Preferably, the filter material comprises one or more folds and/or pleats. This increases the surface area of the filter material and increases the filtering capacity of the filter material.

Preferably, the windows are formed in the filter material.

In this way, only a single material is needed with the windows being formed by a fusing process applied to regions of the filter material.

Preferably, the windows are formed in the filter material by the application of heat and/or pressure.

Preferably, the filter material comprises a PP laminate.

Preferably, the mask comprises a layer of filter material and a layer of transparent material, wherein the layer of filter material comprises a plurality of apertures and the layer of transparent material comprises a plurality of apertures, wherein the layer of filter material and the layer of transparent material are formed as a laminate, and wherein the apertures of the filter material and the apertures of the transparent material do not overlap.

As will be appreciated, the apertures in the filter material overlap with the transparent material to form the windows in the mask and the apertures in the transparent material overlap with the filter material to provide regions through which a wearer of the mask can breathe.

Preferably, the layer of filter material and the layer of transparent material are bonded together around each of the apertures in the filter layer and/or around each of the apertures in the transparent layer.

Preferably, the windows comprise a plurality of strips, rectangles, hexagons, ovals and/or circles.

Preferably, the mask comprises an irregular pattern of windows.

Preferably, the mask comprises a plurality of irregularly shaped windows.

Preferably, the mask comprises a plurality of windows of different sizes and/or shapes.

The use of an irregular pattern of windows and/or windows of different sizes and/or shapes is particularly advantageous because it gives an overall impression of increased transparency superior to the actual amount of transparent window area.

Preferably the windows comprise a plurality of strips.

Preferably, the mask comprises alternating strips of transparent material and filter material.

Preferably, the strips are vertical strips. Alternatively, the strips are horizontal strips.

As will be appreciated, reference to horizontal and vertical is with reference to the orientation of the strips when the mask is being worn by a wearer.

Preferably, the strips are rectangular.

Preferably, the mask comprises a plurality of lines of windows.

Preferably, the lines are vertical lines of windows. Alternatively, the lines are horizontal lines of windows.

Preferably, the mask comprises one or more lines of windows of a first size and/or shape and one or more lines of windows of a second size and/or shape.

Preferably, the ratio between the surface area of the mask comprising windows and the surface area of the mask comprising filter material varies across the mask.

Preferably, there is a higher proportion of the surface area of the mask comprising windows in the mouth region of the mask than in other parts of the mask.

Preferably, the mask comprises a high proportion of the surface area of the mask comprising windows in the mouth region of the mask and a low proportion of the surface area of the mask comprising windows towards the perimeter, preferably towards the sides, top and/or base, of the mask.

Preferably, a high proportion means more than 50% and a low proportion means less than 50%.

In the context of the present invention, the sides of the mask are adjacent in use to a wearer's cheeks, the top proximal to the bridge of the nose and the base proximal to the chin of the wearer.

Preferably, the proportion of the surface area of the mask comprising windows decreases from the mouth region of the mask towards the perimeter, preferably towards the sides, top and/or base, of the mask.

Preferably, the size of the windows is greatest in the mouth region of the mask.

Preferably, the size of the windows decreases from the mouth region of the mask towards the perimeter, preferably towards the sides, top and/or base of the mask.

Preferably, the proportion of the surface area of the mask comprising filter material increases from the mouth region of the mask towards the perimeter, preferably towards the sides, top and/or base of the mask.

Preferably, the proportion of the surface area of the mask comprising filter material increases from the mouth region of the mask towards the sides of the mask.

Preferably, the mask comprises alternating strips of transparent material and filter material, wherein the width of the strips of transparent material decreases from a maximum width at the mouth region of the mask to a minimum width at or near the perimeter of the mask and the width of the strips of filter material increase from a minimum width at or near the mouth region of the mask to a maximum width at or near the perimeter of the mask.

Preferably, the mask comprises alternating strips of transparent material and filter material, wherein the width of the strips of transparent material decreases from a maximum width at the mouth region of the mask to a minimum width at or near the sides, top and/or base of the mask and the width of the strips of filter material increase from a minimum width at or near the mouth region of the mask to a maximum width at or near the sides, top and/or base of the mask.

Preferably, at least about 50% of the surface area of the mask in the mouth region of the mask comprises windows.

Preferably, at least about 60%, preferably at least about 70%, preferably at least about 80%, preferably at least about 90%, preferably at least about 95%, preferably all of the surface area of the mask in the mouth region of the mask comprises windows.

Preferably, reference to a mouth region of the mask means a region of the mask which is positioned in front of the mouth of a wearer when the mask is positioned on the face of a wearer.

Preferably, the mouth region of the mask is a central region of the mask.

Preferably, the mouth region of the mask is positioned at a central region of the mask and towards the top and/or base of the mask.

Preferably, the mask comprises one or more windows outside the mouth region of the mask.

Preferably, the mask comprises one or more windows towards the perimeter of the mask.

Preferably, the mask comprises one or more windows towards the sides, top and/or bottom of the mask.

Preferably, the mask comprises a pattern of windows adjacent to the filter material throughout at least about 50% of the surface area of the mask.

Preferably, the mask comprises a pattern of windows adjacent to the filter material throughout at least about 60%, preferably at least about 70%, preferably at least about 80%, preferably at least about 90%, preferably at least about 95%, preferably all of the surface area of the mask.

Preferably, the mask comprises a nose clip, preferably a deformable nose clip.

Preferably, the mask comprises an exhalation valve.

An exhalation valve allows exhaled air to pass through it freely but prevents the through-flow of inhaled air.

Preferably, the exhalation valve is positioned away from the mouth region of the mask.

Preferably, the exhalation valve is positioned towards the perimeter, preferably towards a side, top and/or base of the mask.

Preferably, the mask is a respirator.

Preferably, one or more of the windows comprise an anti-fog coating, preferably on an inside surface thereof.

As will be appreciated, an inside surface of a window is a surface of the window which is on the inside of the mask, in use, facing towards the wearer.

Preferably, the anti-fog coating comprises a hydrophilic coating, preferably a polymer, hydrogel, or colloid comprising titanium dioxide.

Preferably, one or more of the windows comprise an anti-reflective coating, preferably on an outside surface thereof.

As will be appreciated, an outside surface of a window is a surface of the window which is on the outside of the mask, in use, facing away from the wearer.

Preferably, the mask comprises an adhesive for securing the mask to the face of a wearer.

Preferably, the mask comprises one or more strips of adhesive along at least a part of the perimeter of the mask.

Preferably, the one or more strips of adhesive are provided at the sides of the mask and/or at the top of the mask.

According to another aspect of the present invention, there is provided a face mask for filtering airborne particles, the face mask comprising a plurality of windows bordered by filter material.

Preferably, the mask comprises a plurality of windows in a mouth region of the mask.

According to another aspect of the present invention, there is provided a face mask for filtering airborne particles, the face mask comprising filter material and a plurality of windows, wherein the face mask does not cover the eyes.

In another aspect of the present invention, there is provided a laminate material comprising a layer of filter material and a layer of transparent material, wherein the layer of filter material comprises a plurality of apertures and the layer of transparent material comprises a plurality of apertures, wherein the apertures of the filter material and the apertures of the transparent material do not overlap.

Preferably, the mask comprises one or more straps for securing the mask on a wearer's head.

It will be appreciated that reference to "one or more" includes reference to "a plurality".

Within this specification, the term "about" means plus or minus 20%, more preferably plus or minus 100/0, even more preferably plus or minus 5%, most preferably plus or minus 2%.

Within this specification embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein and vice versa.

DETAILED DESCRIPTION

Example embodiments of the present invention will now be described with reference to the accompanying Figures, in which:-Figure 1 shows a first example of a mask; Figure 2 shows a second example of a mask; Figure 3 shows a third example of a mask; Figure 4 shows a fourth example of a mask; and Figure 5 shows a fifth example of a mask.

The present invention relates to a mask which allows visibility of the wearer's mouth whilst at the same time providing a large surface area for air filtration.

In particular, the invention relates to a face mask which is used to prevent the spread of infectious diseases and to prevent particulates, odours and microorganisms entering the wearer's airway. Typically, medical face masks (for example, surgical masks) are designed to prevent contaminated matter passing from the wearer to third parties and respirators are designed to prevent inhalation of unwanted substances by the wearer, but both provide a degree of protection for the wearer against infection by airborne bacteria and viruses.

Specifically, the invention relates to the provision of a plurality of windows in the mask so that the wearer's mouth can be seen. This improves communication (and hence can reduce medical errors) and provides a friendlier and less threatening appearance for the wearer.

With reference to the Figures, a mask 1 comprises a plurality of windows 2 bordered by filter material 3.

In the example shown in Figure 1, the windows take the form of strips of air-impermeable transparent material 2 separated by strips of filter material 3. As will also be seen from Figure 1, the width of the strips of transparent material 2a, 2b, 2c, 2d, 2e decreases from the mouth region of the face mask towards the sides of the face mask, whilst the width of the strips of filter material 3a, 3b, 3c, 3d, 3e, 3f increases from the mouth region of the face mask towards the sides of the face mask. It is understood that the "width" of the transparent and filter materials refers to the dimension perpendicular to the length of the strip, wherein the length of the strip is the longest dimension.

The above arrangement of strips of transparent material and filter material provides a unique arrangement that provides an optimum balance between the need for the mask to filter airborne particles and the need for the mouth of a wearer to be visible.

In order to secure the mask to the face of a wearer, a pair of straps 4 are provided. In the example shown, the straps are elastic straps and can be attached to the mask via heat bonding, adhesive or via a mechanical fastening.

Figure 2 shows an alternative example of a face mask in which windows of transparent material 2a, 2b, 2c and 2d are provided of varying sizes. As will be seen the windows decrease in width and height from the largest windows 2a, 2b to the smallest windows 2c, 2d.

It is understood that the "width" of the windows refers to the dimension perpendicular to the height of the windows as shown with reference to the vertical orientation of the windows in Figure 2.

Also shown in Figure 2 is the presence of an exhalation valve 5.

The inclusion of an exhalation 5 valve allows the mask to be used as a respirator rather than a surgical mask. An exhalation valve allows exhaled air to pass through the valve and the mask freely but prevents the through-flow of inhaled air.

Exhalation valves are typically flap valves using a disc of elastomeric or silicone material as the 'flap'. The exhalation valve 5 could be glued or heat-bonded to the mask 1 but should be situated in a position that does not obscure the wearer's mouth. For example, as shown in Figure 2, the exhalation valve 5 can be provided to one side of the mask 1, offset from the centre of the mask 1.

The mask 1 shown in Figure 2 also includes a deformable nose clip 6 to help seal and secure the mask around a wearer's nose. The nose clip 6 allows the wearer to shape the top of the mask 1 to be a better fit around the nose. The nose clip 6 could be made from a length of ductile metal wire or strip (such as copper or annealed steel), which is attached to or contained within the mask 1 material.

Figure 3 shows a duck-bill construction in which a plurality of oval windows 2 are provided. The windows 2 are positioned in vertical lines 7 with the size of the windows being greatest in a mouth region 8 of the mask and smallest in side regions 9a, 9b of the mask.

Figure 4 shows a mask in which horizontal strips of transparent material, 2a, 2b, are positioned either side of a strip of filter material 3. In this example, the mask is formed from a flat sheet of material, cut to shape and then bonded together at a join 10 to form the mask shape.

Figure 5 shows a mask similar to that currently used for surgical masks and with a similar layout of alternative strips of transparent material 2a, 2b, 2c, 2d and filter material 3a, 3b, 3c, 3d, 3e to that shown in the mask of Figure 1. In order to provide a greater surface area for filtration, to open up and fit around a wearer's face, and to allow movement of the wearer's jaw, the mask includes pleats 11.

In some examples of construction, the mask is formed from a plurality of air-impermeable transparent regions, bonded to regions of air-permeable filter material that filters the inhaled and exhaled air. The transparent regions can be made from a transparent polymer film, such as PET, PE, PP, PVC, PC, nylon or PVDC. The film can be in the range of 0.01mm to lmm thick. The filter material can be a non-woven fibrous material, developed to provide high filtration efficiency for particles and micro-organisms down to the sub-micron level. This material could be an electret and could be manufactured from PP, PET or fluoropolymers. This material can be a laminate of spun-bonded and melt-bonded non-woven material, to provide good filtration performance coupled with resistance to strike-through of liquids and mechanical robustness. In particular examples, the filter material is at least an N-95 filter material.

The regions of transparent material are bonded to the regions of filter material so that air cannot pass through the join between the two materials. Suitable bonding techniques are heat bonding, ultrasonic welding, laser bonding, solvent bonding or gluing. Bonding methods involving heat (including laser bonding and ultrasonic welding) are preferred, as these can also bond the layers of the filter material together at the bonding line. Alternatively, the transparent regions can be formed by heating and pressing the filter material, so that the non-woven material layers are fused and become transparent in the areas in which the heat and pressure is applied. In this example, a separate transparent film is not required, rather the transparent regions are formed by a fusing process applied to regions of the filter material. A suitable filter material for this is a polypropylene laminate.

As described herein, the regions of transparent material can be strips, rectangles, hexagons, circles, ovals or other shapes. Strips can be vertical or horizontal. The ratio between the area of transparent material and filter material can vary across the mask, so that there is a higher proportion of transparent material in front of the mouth. Preferably, the proportion of the surface area of the mask comprising transparent material directly in front of the mouth should be in the range of 50% to 100%.

The mask can be constructed by cutting and bonding a flat material to form a duck-bill, cup or pleated construction, that fits the contours of the face and seals around the lower half of the face. In these instances, the seams of the mask can be made by the bonding methods described above. Alternatively, the mask can be moulded, by applying heat and pressure, to a sheet of material to form it into a cup shape. This sheet material could be a laminate of filter material and transparent material or, for the case where the transparent regions are formed from fusing the non-woven filter material, just the filter material itself.

In the case where the mask is made from a flat material, the material can be made by a continuous, high-speed manufacturing process. This could involve laminating transparent and filter materials, both fed from reels of material, using heat and pressure. Before laminating together, the filter material and the transparent material are individually perforated to create apertures and then brought together so that the apertures of each material do not overlap. The materials are then bonded to each other so that a seal is made around each aperture in the transparent material so that the only route for air to pass through the laminated material is through the filter material. The materials could also be bonded together around each aperture of the filter material. Alternatively, the transparent windows could be formed, again using a continuous roll-feed machine, by applying heat and pressure to the filter material in certain regions, to fuse the non-woven material and render it transparent in those regions.

The mask may contain bulges, folds or pleats in it to further increase the surface area available for air flow and increase the comfort, fit and effectiveness of the mask for breathing and speaking.

The transparent film may incorporate an anti-fogging coating on its inside surface and an anti-reflective coating on its outside surface. Possible materials for anti-fogging are hydrophilic coatings such as polymers and hydrogels, and colloids containing titanium dioxide.

The perimeter of the mask may incorporate a strip of skin-adhesive material, to provide a light adhesive bond with the skin and reduce leakage around the mask. The strip can be fixed to the perimeter of the mask using, for example, an acrylic adhesive and the skin-contacting adhesive can be covered by a lining paper. After the mask has been placed into position on the wearer's face, the strip of lining paper can be removed so that the skin adhesive is exposed and lightly adheres to the skin. Low-tack acrylic-based adhesives can be used for the skin-adhesive.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications are covered by the appended claims.

Claims

CLAIMS1. A face mask for filtering airborne particles, the face mask comprising a filter material and a plurality of windows, wherein the plurality of windows are in a mouth region of the mask.
2. A face mask according to claim 1, wherein the windows are adjacent to the filter material.
3. A face mask according to any preceding claim, wherein the windows are impermeable to air.
4. A face mask according to any preceding claim, wherein the windows are bordered by filter material on at least two edges thereof.
5. A face mask according to any preceding claim, wherein the windows are surrounded by filter material.
6. A face mask according to any preceding claim, wherein the filter material is at least an N-95 filter material.
7. A face mask according to any preceding claim, wherein the windows are formed in the filter material.
8. A face mask according to any of claims 1 to 6, wherein the mask comprises a layer of filter material and a layer of transparent material, wherein the layer of filter material comprises a plurality of apertures and the layer of transparent material comprises a plurality of apertures, wherein the layer of filter material and the layer of transparent material are formed as a laminate, and wherein the apertures of the filter material and the apertures of the transparent material do not overlap.
9. A face mask according to any preceding claim, wherein the windows comprise a plurality of strips, rectangles, hexagons, ovals and/or circles.
10. A face mask according to claim 9, wherein the windows comprise a plurality of strips.
11. A face mask according to claim 10, wherein the mask comprises alternating strips of transparent material and filter material.
12. A face mask according to claim 10 or 11, wherein the strips are vertical strips.
13. A face mask according to any preceding claim, wherein the ratio between the surface area of the mask comprising windows and the surface area of the mask comprising filter material varies across the mask.
14. A face mask according to any preceding claim, wherein there is a higher proportion of the surface area of the mask comprising windows in the mouth region of the mask than in other parts of the mask.
15. A face mask according to any preceding claim, wherein the mask comprises a high proportion of the surface area of the mask comprising windows in the mouth region of the mask and a low proportion of the surface area of the mask comprising windows towards the perimeter, preferably towards the sides, top and/or base, of the mask.
16. A face mask according to any preceding claim, wherein the proportion of the surface area of the mask comprising windows decreases from the mouth region of the mask towards the perimeter, preferably towards the sides, top and/or base, of the mask.
17. A face mask according to any preceding claim, wherein the size of the windows is greatest in the mouth region of the mask.
18. A face mask according to any preceding claim, wherein the size of the windows decreases from the mouth region of the mask towards the perimeter, preferably towards the sides, top and/or base of the mask.
19. A face mask according to any preceding claim, wherein the mask comprises an irregular pattern of windows.
20. A face mask according to any preceding claim, wherein the mask comprises a plurality of irregularly shaped windows and/or windows of different sizes and/or shapes.
21. A face mask according to any preceding claim, wherein the mask comprises alternating strips of transparent material and filter material, wherein the width of the strips of transparent material decreases from a maximum width at the mouth region of the mask to a minimum width at or near the perimeter of the mask and the width of the strips of filter material increase from a minimum width at or near the mouth region of the mask to a maximum width at or near the perimeter of the mask.
22. A face mask according to any preceding claim, wherein at least about 50% of the surface area of the mask in the mouth region of the mask comprises windows.
23. A face mask according to any preceding claim, wherein the mask comprises an exhalation valve.
24. A face mask according to claim 23, wherein the exhalation valve is positioned away from the mouth region of the mask.
25. A laminate material comprising a layer of filter material and a layer of transparent material, wherein the layer of filter material comprises a plurality of apertures and the layer of transparent material comprises a plurality of apertures, wherein the apertures of the filter material and the apertures of the transparent material do not overlap.