GB2605122A

GB2605122A - Face mask

Info

Publication number: GB2605122A
Application number: GB2102009.4A
Authority: GB
Inventors: Reardon David
Original assignee: Bloom In Box Ltd
Current assignee: Bloom In Box Ltd
Priority date: 2021-02-12
Filing date: 2021-02-12
Publication date: 2022-09-28
Anticipated expiration: 2041-02-12
Also published as: GB2605122B; GB2604957A; GB202102009D0

Abstract

A face mask 100 comprising a compliant base part 101 formed from a single piece having a profiled contact surface for abutment against a face of a wearer and a removable filter housing 102 shaped to interface with an exterior surface of the base part, the removeable filter housing comprising a washable filter element 103, and at least one fitting for securing the face mask to the face of the wearer. The modular construction allows various sizes of base part to be used with a single sized filter housing. The base part may have an inner surface profile defined by an arc of a circle.

Description

FACE MASK

BACKGROUND

Personal protective equipment (PPE) is commonly used by professionals working in industries such as medicine and construction. Face masks are an example of PPE and are used to prevent the wearer inhaling potentially harmful particles, such as viruses, bacteria or hazardous dust.

Face masks come in many grades, varying from simple cloth face masks that offer a basic level protection all the way to medical grade N95 or FFP3 respirators that are capable of filtering 99% of particles as small as 0.3 microns in diameter.

Since the onset of the COVID-19 pandemic there has been a surge in the use of face masks both within medical settings and by the general public, in part due to governments mandating that face masks be worn in public spaces. Face masks are seen as a way to control the spread of infection, serving as barrier that reduces both the risk of the wearer becoming infected and the risk of infection being spread by a C\J 15 wearer, for example if the wearer is asymptomatic (does not show symptoms of the C\I disease).

o Most medical grade face masks or respirators are single use face masks that are intended to be disposed of once they have been worn. As well as being expensive due to the costs involved in replacing the masks, this generates a large amount of waste that cannot be recycled by conventional means. As a result, there has been a move towards reusable cloth face masks that can be washed and worn several times. However, such cloth face masks do not offer the same degree of protection as medical grade face masks or respirators.

While face masks or respirators with replaceable filters exist, these are generally bulky to wear and expensive to manufacture. In addition, it can be difficult to achieve a good fit between the mask and the wearer's face.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a face mask comprising: a compliant base part formed from a monolithic material, the base part comprising a profiled contact surface for abutment against a face of a wearer; a removable filter housing shaped to interface with an exterior surface of the base part, the removeable filter housing comprising a washable filter element; and, at least one fitting for securing the face mask to the face of the wearer.

Face shapes and sizes vary considerably between different people depending on attributes such as age, race and gender etc. Conventional face masks are often either sold in one size or in a very limited range of sizes, and they are often unsuitable for young children. The two-piece arrangement of base part and filter housing of the present invention means that the removable filter housing can be standardised for all wearers, and the compliant base part can be easily manufactured in a continuous range of sizes to correctly fit correctly almost any face shape and size.

In addition, the filter housing can be separated from the base part to allow the filter element to be washed (for example by pouring boiling water through it) which allows the filter element to be used multiple times.

Furthermore, when the washable filter element does need to be replaced (i.e. once it has been washed a maximum number of times) the base part can be reused, thereby reducing the amount of waste created when using PPE, whilst still ensuring a high level of protection (i.e. much greater than is possible with cloth face masks). The washable filter element may be manufactured in accordance with an internationally recognised C\J standard such as FFP2, FFP3, N95 or any other equivalent standard or classification.

C\I In addition, the face mask of the present invention can be (and preferably is) manufactured entirely from non-metal materials. This has the benefit that the face mask can be worn by a wearer while inside an MRI scanner or similar device. For example, the base part may be formed of an elastomeric material such as rubber, the filter housing may be formed from plastic, the fitting may be formed of plastic or a non-metal textile, and the filter element may be formed of textile/cloth or any other suitable non-metal filter material.

In use, the profiled contact surface of the base part is placed against the face of the wearer and the removable filter housing is secured to the exterior surface of the base part. This forms (substantially) airtight seals between the base part and the filter housing and between the base part and the face of the wearer.

Monolithic means that the base part is formed of a single, continuous piece of material. For example, the base is preferably formed of a single piece of a soft and/or elastomeric material such as rubber or silicone.

The removable filter housing is preferably rigid. For example, it may be formed of plastic (e.g. polypropylene).

One skilled in the art will appreciate that the face mask may also be referred to as a respirator or dust mask.

Preferably, a profile of the profiled contact surface is defined by an arc of a circle. That is, when viewed in a plane perpendicular to a vertical direction of the face mask (i.e. the vertical direction when the face mask is being worn) the profiled contact surface of the base part lies on the arc of a circle.

Having a profile defined by an arc of a circle means that the face mask can be manufactured in a range of sizes simply by adjusting the radius of curvature of the profile; there is no need to change any other dimensions of the face mask, and the same filter housing can be used with base parts having different sizes of profiled inner surface (that is, the filter housing is universal, i.e. it is common to all sizes of base part). This makes the face mask simpler to manufacture in a wide range of sizes when compared to existing face masks Alternative methods for obtaining a good fit include scanning a wearer's face and 3D printing a custom mask. However, such a method is expensive and relatively slow, whereas the face mask of the present invention can be manufactured quickly in a range of sizes (by adjusting the radius of curvature of the profile) in large quantities (e.g. by C\J injection moulding).

C\I Even more preferably, the profile has a constant radius of curvature. That is, the radius of curvature is constant in the vertical direction of the mask, i.e. it is the same in all planes perpendicular to the vertical direction. In other words, the profiled contact surface has a profile shaped like (part of) an exterior surface of a cylinder.

Optionally, the washable filter element may be removable from the filter housing. This allows the filter housing to be reused when the washable filter needs to be replaced (i.e. when it has been washed a maximum number of times). Alternatively, the washable filter element may be an integral or in-moulded component of the filter housing that is not removable, such that the entire filter housing is replaced when the washable filter needs replacing.

The removable filter housing may comprise one or more fitting attachment elements for attachment to the at least one fitting. For example, the at least one fitting may be attached to the one or more fitting attachment elements and, in use, thereby urge the removable filter housing against the exterior surface of the base part.

Alternatively or additionally, fitting attachment elements may be provided on the base part. In this case, the removable filter housing may be secured to the base part by alternative means. For example, the interface between the removable filter housing and the base part may comprise one or more clips or be an interference fit.

The fitting attachment elements may comprise living hinges. As is known a person skilled in the art, a living hinge is a hinge made from the same material as the two components it connects.

The fitting for securing the face mask to the face of the wearer may be coupled to the fitting attachment elements and may optionally comprise one or more straps, which may be elastic. For example, the fitting may comprise a single strap that goes around the wearer's head, or it may comprise multiple straps, for example a pair of ear straps.

Optionally, the interface between the removable filter housing and the base part may be a tongue and groove interface. For example, the base part may have one or more grooves and the removable filter housing may comprise one or more tongues or protrusions, or vice versa.

The side walls of the base part connecting the exterior surface to the profiled contact surface may optionally be angled inward from the exterior surface to the profiled contact surface. The fit of the face mask can be altered by adjusting the angle to accommodate different face sizes. This again makes the face mask simple to C\J manufacture in a wide range of sizes simply by adjusting the angle. C\I

BRIEF DESCRIPTION OF THE DRAWINGS

An example of the present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 shows an exemplary face mask; Figure 2 shows an exploded view of the face mask; Figure 3 shows a base part of the face mask; Figures 4a-c show alternative views of the base part; Figure 5 shows a filter housing of the face mask; Figure 6 shows an alternative face mask; Figure 7 shows a base part of the alternative face mask; Figures 8a and 8b show a filter housing of the alternative face mask; and, Figures 9a-e illustrate conceptually how the shape of a mould for the base part is formed.

DETAILED DESCRIPTION

The present invention provides an improved face mask suitable for use in both medical and non-medical settings. The face mask can be provided with a filter element having a suitable grade (e.g. FFP2, FFP3, N95 etc.) for the intended use, thereby allowing the face mask to be used in scenarios ranging from avoiding the inhalation of nuisance dust to preventing the spread of contagious bacteria and viruses.

The face mask can be easily manufactured in different sizes, making it suitable for use by almost any wearer, including children.

Figures 1 and 2 show an exemplary face mask 100. The face mask 100 comprises a base part 101, a filter housing 102, a filter element 103 (in this case a disc) received in the filter housing 102, and a plurality of fitting attachment elements 104 in the form of slotted tabs.

In use, the base part 101 abuts against the face of a wearer, and the filter housing 102 is held against the base part 101 by one or more fittings (not shown), which may for example be in the form of one or more elasticated straps coupled to the fitting attachment elements 104. Any alternative fitting attachment elements may be used provided that they are suitable for attachment to a fitting (such as an elasticated strap) for enabling the face mask to be attached to a wearer's face/head. For example, the fitting attachment elements may instead be loops or similar.

The filter element 103 may be any suitable filter having the correct grade for the intended purpose (e.g. FFP2, FFP3, N95). In addition, the filter element 103 is O washable in order to allow it to be reused. For example, the filter element 103 may be washable by pouring a (predetermined) volume of boiling water through the filter Ci° 20 element 103, optionally for a predetermined duration of time.

The filter element 103 may optionally be permanently coupled to the filter housing 102 during manufacture of the face mask 100 (e.g. it may be in-moulded). Alternatively, the filter element 103 may be removable from the filter housing 102, thereby allowing the filter housing to be washed separately from the filter housing 102 and also allowing the filter element 103 to be replaced (e.g. after it has been used/washed a predetermined maximum number of times).

Moving on, a profile view of the base part 101 is shown in Figure 3. The base part 101 has a profiled contact surface 301 for abutment against a wearer's face, and a nose section 302 shaped to partially surround the wearer's nose when in use.

The base part 101 is formed of a compliant material. For example, it may be formed of a soft and/or elastomeric material such as rubber or silicone. One skilled in the art will appreciate that the base part may be formed from any one of numerous materials with suitable durability and elasticity characteristics. Regardless of the material used, the base part 101 is formed from a single piece of material (i.e. it is monolithic).

Figures 4a, 4b and 4c show side, front and top views respectively of the base part 101.

As shown in Figure 4b, the base part 101 features an exterior surface 401 that has a groove 402 for receiving the filter housing 102 (this groove is also visible in Figure 2). In this way, a tongue or similar (described later) of the filter housing 102 can be received within the groove 402. The exterior surface 401 may also be referred to as housing abutment surface.

The conformable material of the base part 102 assists in forming a substantially airtight seal between the base part 101 and the filter housing 102, thereby preventing (potentially harmful) gases and particles from permeating through a gap between the base part 101 and the filter housing 102. One skilled in the art will appreciate that a substantially airtight seal means that negligible/insignificant amounts of air (or other gases) can diffuse through the gap in question (e.g. between the base part 101 and the filter housing 102) at normal air pressures generated when a wearer breathes while wearing the face mask 100.

Although the groove 402 allows for a particularly robust seal to be formed, the groove C\J 402 is not essential for achieving an airtight seal, and other interfaces could be used C\I to achieve the same result. For example, the exterior surface 401 could instead be flat and abut against a flat surface of the filter housing 102. In addition, one or more clips or other coupling elements (not shown) could be used to urge/hold an inner surface of the filter housing 102 against the exterior surface 401 of the base part 101 with a force sufficient to form an airtight seal. Other interfaces will be apparent to a person skilled in the art. For example, the interface between the base part 101 and the filter housing 102 may be an interference fit.

The base part 101 is shaped to form a substantially airtight seal against a face of a wearer. This is achieved through the profiled contact surface 301. The profiled contact surface 301 has a profile defined by an arc of a circle, as visible in Figure 4c. That is, when viewed in a plane perpendicular to a vertical direction of the face mask (i.e. the vertical direction when the face mask is being worn, that being the direction that runs from the nose section 302 to the directly opposing part of the perimeter of the base part 101) the profiled contact surface 301 of the base part lies on the arc of a circle.

The illustrated profile has a constant radius of curvature (when viewed in a plane perpendicular to the vertical direction) labelled R in Figure 4c.

The base part 101 can be manufactured in a variety of sizes simply by using a different radius of curvature R. No other changes to the design are necessary. In particular, the outline of the base part 101/exterior surface 401 (and therefore the groove 402) is the same for all sizes regardless of the chosen radius of curvature. In this way, the face mask 100 provides a simple design that can easily be manufactured to fit different face sizes. The filter housing 102 and the filter element 103 are universal to all base parts 101 (i.e. the same filter housing 102 and filter element 103 can be used with base parts 101 having different radii of curvature).

As also visible in Figure 4c, the side walls 403 of the base part 101 that connect the exterior surface 401 to the profiled contact surface 301 are tapered or angled. That is, the side walls 403 are angled inward relative to (i.e. non-perpendicular to) the exterior surface 401 (such that a cross-sectional area of the base part 101 in a plane perpendicular to the exterior surface 401 decreases from the exterior surface 401 to the profiled contact surface 301).

Adjusting the angle between the side walls 403 and the exterior surface 401 (the housing abutment surface) allows the fitting of the face mask 100 to be further adjusted to fit different face shapes and sizes because it adjusts the size of the profiled contact surface 301 without affecting the size of the exterior surface 401, meaning that C\J several sizes of base part 101 can be used with the same filter housing 102. The angle C\I of the side walls 403 can be adjusted in addition to (or as an alternative to) adjusting the radius of curvature of the profiled contact surface 301. LtD

Moving on, Figure 5 illustrates the filter housing 102. The filter housing 102 has a tongue 501 shaped to interface with the groove 402 of the base part 101. The filter housing 102 additionally comprises a nose section 502 shaped to accommodate a wearer's nose in the face mask (similar to the nose section 302 of the base part 101) and a filter aperture 503 for receiving the filter element 103. The illustrated filter housing 102 is strengthened by reinforcing elements 504 which span the filter aperture 503.

As discussed earlier, the filter element 103 may be either permanently coupled to the filter housing 102 during manufacture of the filter housing 102 (e.g. it may be in-moulded), or it may be a removable element that can be separated from the filter housing 102, e.g. to wash and/or replace the filter element 103. The filter element 103 may be received in a groove (not shown) on the filter housing 102, or it may be retained by some other means, such as one or more clips (not shown) on the filter housing 102 or an interference fit. Regardless of the means by which the filter element 103 is retained in the filter housing 102, a substantially airtight seal is formed between the filter element 103 and the filter housing 102 when the filter element 103 is installed in the filter housing 102 in order to ensure that no significant amount of air can leak around the filter element 103 when the face mask 100 is in use.

The filter housing 102 may be formed of a material such as plastic. The filter housing 102 (excluding the filter element 103) may also be formed from a single piece of material (i.e. it may be monolithic).

The filter housing 102 (and in particular the tongue 501 of the filter housing 102) has a shape/outline that corresponds to the shape/outline of the base part 101 (in particular the exterior surface 401 and groove 402 of the base part 101). This allows the tongue 501 of the filter housing 102 to be received in the groove 402 of the base part when the base part 101 and the filter housing 102 are pressed together, thereby forming a substantially airtight seal between the filter housing 102 and the base part 101.

The tongue and groove interface could optionally be reversed such that the filter housing 102 comprises one or more grooves and the base part 101 comprises one or more tongues.

In the illustrated example, the fitting attachment elements 104 are integrally attached to the filter housing 102. As previously mentioned, the illustrated fitting attachment CJ elements 104 are in the form of slotted tabs protruding from the outer surface of the C\I filter housing 102. The fitting attachment elements 104 may optionally be coupled to the filter housing 102 by means of a hinge mechanism, for example a living hinge.

CD In use, at least one fitting, such as a strap, is coupled to the fitting attachment Ci° 20 elements 104 (for example, by tying the fitting to one or more of the fitting attachment elements 104 and/or looping it through the slots of one or more of the fitting attachment elements 104) and used to attach the face mask 100 to the face of the wearer.

One skilled in the art will appreciate that numerous different types of fittings and fitting attachment elements 104 are suitable for use with the face mask 100 and that the illustrated tabs are optional and just one example of a fitting element 104 that could be used.

To use or wear the face mask 100, the wearer first ensures that the filter element 103 is installed in the filter housing 102. If the filter element 103 is removable, this may involve inserting the filter element 103 into the filter aperture 503. The user then loosely couples the base part 101 and filter housing 102 together by aligning the tongue 501 of the filter housing 102 with the groove 402 of the base part and pressing the base part 101 and the filter housing 102 towards each other.

The wearer then holds the face mask 100 in this loosely coupled configuration and places the profiled contact surface 301 of the base part 101 against their face. With the face mask 100 held against their face, the wearer can then use the fittings (not shown) to secure the face mask 100 in place. For example, if the fittings are straps, this step may involve adjusting the straps and placing them around the wearer's head or ears to thereby secure the face mask 100 to the wearer's face.

Alternatively, the wearer may first place the base part 101 against their face and then place the filter housing 102 against the base part 101 as described above. One skilled in the art will appreciate that the exact steps performed when fitting the face mask 100 may be altered according to the wearer's preference.

Due to the fitting attachment elements 104 being located on the filter housing 102, the fittings (not shown) press/urge the filter housing 102 against the base part 101 while the face mask is being worn. This ensures both that the base part 101 and the filter housing 102 do not become separated, and that the filter housing 102 is pressed firmly against the base part 101, thereby forming the required substantially airtight C\J seal between the base part 101 and the filter housing 102.

C\I While wearing the face mask 100, all air inhaled and exhaled by the wearer passes through the filter element 103. Depending on the grade of the filter element 103, this ensures that the wearer does not inhale unwanted particles and also ensures that the wearer does not spread unwanted particles when exhaling.

An alternative face mask 600 is shown in Figure 6. As with the face mask 100 in Figure 1, the alternative face mask 600 has a base part 601, a filter housing 602, a filter element 603 and a plurality of fitting attachment elements 604 in the form of slotted tabs.

The base part 601, shown separately in Figure 7, shares all of the features of the base part 101 of the face mask 100 in Figure 1, including a profiled contact surface 701 and an exterior surface 702. In addition, the illustrated base part 601 features a plurality of fitting grooves 703 for receiving the fitting attachment elements 604. It should be understood that the base part 101 of the face mask 100 in Figure 1 could also have such fitting grooves 703. These fitting grooves 703 mean that the filter housing 602 can be manufactured with the fitting attachment elements 604 forming part of the surface that contacts the base part 101, which simplifies manufacture.

The filter housing 602 is shown in more detail in Figures 8a and 8b. The filter housing 602 has a tongue 801 shaped to interface with a groove of the base part 601. The filter element 603 is received in a filter aperture 803 which is strengthened by a reinforcing element 802.

Instead of a round filter element 103 as illustrated in Figure 1, the filter housing 602 in Figures 8a and 8b has a larger filter element 603 which has generally the same shape as the cross section of the base part 601 (i.e. the cross section/outline of the filter is substantially the same as the cross section/outline of the exterior surface 702 of the base part 601). This larger filter element 603 has an increased surface area, which in turn increases the amount of air that can pass through the filter element 603 and makes it easier for the wearer to breathe, thereby increasing wear comfort.

The face mask 600 in Figure 6 is used in the same manner as the face mask 100 of Figure 1.

Figures 9a-e illustrate conceptually how a mould for the base part 101 is formed. It should be understood that these steps do not necessarily reflect the actual steps performed when manufacturing the mould.

C 15 Figure 9a shows the general shape or outline 901 of the base part 101 (and therefore C\I the outline of the mould for the base part 101). In Figure 9b, this outline is extruded to form a three-dimensional block having a cross section corresponding to the shape O in Figure 9a; the resulting shape 902 is shown in Figure 9c. This shape may optionally be extruded with a taper to form the angled side walls 403 of the base part 101. Ci°

Figure 9d illustrates how a cylindrical cut having a known radius is applied to the shape 902 to form the resulting shape 903 of the mould as shown in Figure 6e.

By forming moulds having different radii, different mould shapes can be formed that allow the base part 101 to fit different face sizes as described earlier.

The relatively simple geometric shape of this mould makes it easy and cost effective to manufacture. A mould having this shape can be formed using various techniques, such as wire eroding, spark erosion, cutting etc. Both the base part 101 and the filter housing 102 of the face mask 100 are preferably manufactured using injection moulding. In particular, the filter element 103 is preferably formed as an integral component of the filter housing 102 by over moulding the filter during the injection moulding process.

The face mask 100 could alternatively be manufactured using alternative methods such as 3D printing, but injection moulding is preferred due to the speed and volumes at which the components of the face mask can be manufactured.

Claims

CLAIMS1. A face mask comprising: a compliant base part formed from a monolithic material, the base part comprising a profiled contact surface for abutment against a face of a wearer; a removable filter housing shaped to interface with an exterior surface of the base part, the removeable filter housing comprising a washable filter element; and, at least one fitting for securing the face mask to the face of the wearer.
2. The face mask of claim 1, wherein a profile of the profiled inner surface is defined by an arc of a circle.
3. The face mask of claim 2, wherein the profile has a constant radius of curvature.
4. The face mask of any preceding claim, wherein the washable filter element is removable from the removable filter housing.
5. The face mask of any preceding claim, wherein the removable filter housing comprises at least one fitting attachment element for attachment to the at least one fitting, and wherein the fitting is arranged to, in use, urge the removable filter housing against the exterior surface of the base part.
6. The face mask of claim 5, wherein the at least one fitting attachment element is a living hinge.
7. The face mask of any preceding claim, wherein the at least one fitting is a strap.
8. The face mask of any preceding claim, wherein an interface between the removable filter housing and the base part is a tongue and groove interface.
9. The face mask of any preceding claim, wherein side walls of the base part are inwardly angled from the exterior surface to the profiled contact surface.