GB2611877A

GB2611877A - Face mask respirator

Info

Publication number: GB2611877A
Application number: GB2212716.1A
Authority: GB
Inventors: Ezekiel Dean
Original assignee: Design Abled Ltd
Current assignee: Design Abled Ltd
Priority date: 2021-09-01
Filing date: 2022-09-01
Publication date: 2023-04-19
Also published as: GB2611877A8; GB202212716D0

Abstract

A facemask respirator comprising: a facemask body 550; at least one inhalation port configured to filter air entering the respirator; at least one exhalation port configured to filter air leaving the respirator; and a replaceable exhalation filter 558 securable to the at least one exhalation port. The facemask body may be transparent, and can be formed of a thermoplastic elastomer which has be compounded with an anti-fog additive. An exhalation pathway may exist through the at least one exhalation port which comprises a one-way valve to prevent the inlet of air during inhalation of a user. The inhalation port may also comprise a further filter module 572 which comprises a pleated filter pack 552 with an overmoulded thermoplastic gasket, and is attached to the inhalation port using a bayonet fitting. The exhalation filter 558 may be attached to the exhalation port using a bayonet fitting or threaded on. The facemask respirator is intended to protect the user against harmful airborne agents and particles.

Description

FACE MASK RESPIRATOR

Field of the Invention

The present invention relates to face masks, and in particular, but not exclusively, the invention concerns medical face masks.

Background

During the Covid-19 pandemic face masks and face coverings were recommended and/or required in many situations, to reduce the chances of transmitting the virus. One issue with the use of such masks and covering is that deaf, hard-of-hearing and any other persons who rely on lip-reading or otherwise seeing a user's mouth to communicate are unable to do so when the user is wearing a face mask. Further to this, the inability to see a user's expressions can make communication difficult for everyone. As such, efforts have been made to create a face mask which allows a user's mouth to be seen.

One type of face mask created is a mask made of fabric and/or opaque plastic but with a window over the mouth made of a transparent plastic. While such face masks do allow a view of a user's mouth, they can be difficult to manufacture (and so are more costly) given the need to incorporate the window into the mask. Further to this, the masks still allow for a significant amount of transmission of exhaled air through the fabric part, and/or around the edges of the mask, which causes glasses to fog up.

Another type of face mask created is a face mask with a cover which is constituted of a transparent plastic. Since the transparent plastic is not breathable, air filters are incorporated into the face mask to provide breathability. The incorporation of air filters increases the cost and complexity of manufacturing the face masks. Further to this, the air filters can obscure the view of a user's mouth.

Embodiments of the present invention seek to provide an improved face mask which overcomes/ameliorates some or all of the disadvantages associated with known face masks.

A respirator is a wearable device that is designed to protect the user against harmful airborne agents and particles. It is worn over the face of the user and filters the air that they breathe.

There are multiple types and forms of respirator. Some are as simple as a dust mask that is worn over the mouth. Others are a full face mask that encloses the mouth and nose.

In some situations, the important features of an effective respirator are the seal around the nose and mouth, and the level of filtration. The seal around the nose and mouth ensures that all air passes through the filtration layers. The cleaning of the breathable air is provided by forcing it through one or more layers of filtration material.

A respirator or face mask is a wearable device that is designed to protect the user against harmful airborne agents and particles. It is worn over the face of the user and filters the air that they breathe.

Traditionally, face masks and respirators have been opaque in material/colour. This can however impede communication. It is beneficial for a person to be able to see the lips of a person that is speaking, to enable lip reading. This is especially important for those that are hard of hearing and rely upon lip reading.

Summary of invention

According to a first aspect, there is provided a facemask respirator comprising: a facemask body; at least one inhalation port configured to filter air entering the respirator; at least one exhalation port configured to filter air leaving the respirator; a replaceable exhalation filter securable to the at least one exhalation port.

According to some examples, the facemask body is transparent.

According to some examples, an exhalation pathway through the at least one exhalation port comprises a one-way valve that prevents the inlet of air during inhalation of a user.

According to some examples, the facemask respirator comprises: a further filter module attached to the facemask body at the at least one inhalation port.

According to some examples, the further filter module comprises a pleated filter pack with an overmoulded thermoplastic elastomer gasket.

According to some examples, the filter module comprises a thermoplastic elastomer gasket overmoulded to a filtration media disc.

According to some examples, the further filter module is attachable to the facemask body at the at least one inhalation port using a bayonet fitting and wherein the second filter module is attachable to the facemask body at the at least one exhalation port using a bayonet fitting.

According to some examples, the facemask respirator comprises: a cap configured to be attached to the at least one exhalation port to secure an exhalation filter of the second filter module in place.

According to some examples, the facemask body comprises an anti-fog additive. According to some examples, the facemask respirator is formed of a thermoplastic 35 elastomer.

According to some examples, the anti-fog additive and the thermoplastic elastomer are compounded together.

According to some examples, the facemask respirator comprises an EN-1827 respirator.

According to some examples, the at least one inhalation port comprises two inhalation ports According to some examples, the exhalation filter is securable to the exhalation port using a thread on the exhalation filter and a thread on the exhalation port.

According to some examples, the exhalation filter is securable to the exhalation port via an interference fit.

According to a second aspect there is provided a face mask comprising: a transparent cover for a user's mouth and nose; one or more air vents for venting air from within the cover to outside the cover; and wherein the cover comprises one or more cut outs, and wherein the face mask comprises: a filter pad placed over the one or more cut outs.

According to some examples, the cover is formed by a sheet.

According to some examples, the sheet comprises a boundary and wherein in use the boundary of the sheet contacts a user's face.

According to some examples, the one or more air vents are positioned at the boundary of the sheet.

According to some examples, the one or more air vents are at the boundary of the sheet.

According to some examples, the face mask comprising: a skirt at the boundary of the sheet.

According to some examples, the sheet forms the one or more air vents.

According to some examples, the one or more air vents are moulded as part of a body of the face mask.

According to some examples, the one or more air vents are moulded as part of the sheet.

According to some examples, the one or more air vents are moulded as part of the cover.

According to some examples, the one or more air vents are built into the body of the 30 face mask.

According to some examples, the one or more air vents are built into the sheet. According to some examples, the one or more air vents are built into the cover. According to some examples, the boundary of the sheet is formed by the skirt and the one or more air vents According to some examples, the skirt is formed by the sheet.

According to some examples, the one or more air vents are configured to direct breath from a user onto the face of the user.

According to some examples, the one or more air vents comprise two or more air vents. According to some examples, the one or more air vents comprise three air vents. According to some examples, the face mask comprises one or more attachment straps operable to hold the face mask on a user's face.

According to some examples, the face mask comprises one or more pairs of attachment straps, wherein in use the attachment straps of each pair of attachment straps fasten together to hold the face mask on a user's face.

According to some examples, each pair of attachment staps comprises one or more respective strap fasteners for fastening the attachment straps of each pair of attachment straps together.

According to some examples, the face mask comprises a plurality of snap fasteners, wherein the plurality of snap fasteners are arranged in one or more rows.

According to some examples, a first attachment strap of each pair of attachment straps comprises one or more male parts of the one or more snap fasteners and a second attachment strap of the or each pair comprises one or more female parts of the one or more snap fasteners.

According to some examples, at least one of the one or more air vents is positioned to be adjacent a user's chin when the face mask is in use.

According to some examples, one of the one or more air vents is positioned to be adjacent a user's cheek when the face mask is in use.

According to some examples, another air vent is positioned to be adjacent a user's other cheek when the face mask is in use.

According to some examples, the face mask comprises an anti-fog additive. According to some examples, the anti-fog additive is built into the cover.

According to some examples, the face mask comprises an anti-microbial additive.

According to some examples, the anti-microbial additive is built into the cover.

According to a third aspect, there is provided a face mask comprising: a transparent cover for a user's mouth and nose and one or more air vents for venting air from within the cover to outside the cover.

According to some examples, the face mask comprises a sheet which forms the cover.

According to some examples, the sheet comprises a boundary, wherein in use the boundary of the sheet contacts a user's face.

According to some examples, the or each air vents is at the boundary of the sheet. According to some examples, the or each air vent is at the boundary of the sheet.

According to some examples, the face mask comprises a skirt at the boundary of the sheet.

According to some examples, the sheet forms the or each air vent.

According to some examples, the boundary of the sheet is formed by the skirt and the one or more air vents.

According to some examples, the skirt is formed by the sheet.

According to some examples, the sheet is transparent.

According to some examples, the face mask comprises two or more air vents.

According to some examples, the face mask comprises three air vents.

According to some examples, the face mask is shaped to conform with a user's face. According to some examples, the face mask comprises one or more attachment straps operable to hold the face mask on a user's face.

According to some examples, the face mask comprises one or more pairs of attachment straps, wherein in use the attachment straps of the or each pair fasten together to hold the face mask on a user's face.

According to some examples, the or each pair of attachment staps comprising one or more respective strap fasteners for fastening the attachment straps of the or each pair 15 together.

According to some examples, the face mask comprises a plurality of snap fasteners, wherein the snap fasteners are arranged in one or more rows.

According to some examples, a first attachment strap of the or each pair comprises one or more male parts of the one or more snap fasteners and a second attachment strap of the or each pair comprises one or more female parts of the one or more snap fasteners.

According to some examples, the or one of the air vents is positioned to be adjacent a user's chin when the face mask is in use.

According to some examples, the or one of the air vents is positioned to be adjacent a user's cheek when the face mask is in use.

According to some examples, another of the air vents is positioned to be adjacent a user's other cheek when the face mask is in use.

According to some examples, the face mask comprises an anti-fog additive.

According to some examples, the anti-fog additive is built into the cover.

According to some examples, the face mask comprises an anti-microbial additive.

According to further aspects, there is provided a method of manufacture of any of the first to third aspects and their examples.

Brief description of Figures

FIG. 1 is an illustrative representation of a facemask, in front view, in accordance with some examples; FIG. 2 is an illustrative representation of a facemask, in front/side view, with filter pad separated from cover for clarity of features, in accordance with some examples; FIG. 3 is an illustrative representation of a facemask, in front/side view, in accordance with some examples; FIG. 4 is an illustrative representation of a facemask, in side view, in accordance with

some examples;

FIG. 5 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in front/side exploded view, in accordance with some examples; FIG. 6 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in front/side view, in accordance with some examples; FIG. 7 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in front/side view, in accordance with some examples; FIG. 8 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in rear view, in accordance with some examples; FIG. 9 is an illustrative representation of an anti-fog thermoplastic elastomer additive and manufacturing process, as a system diagram, in accordance with some examples; FIG. 10 is an illustrative representation of a facemask with fasteners along the straps, in front view, in accordance with some examples; and FIG. 11 is an illustrative representation of a facemask with fasteners along the straps, in side view, in accordance with some examples.

Detailed description

Face Mask According to some examples, there is provided a face mask comprising a transparent cover for a user's mouth and nose and one or more air vents for venting air from within the cover to outside the cover.

A filter pad may be placed over the one or more cut outs from the mask body. This provides filtration of the air passing into and out of the mask.

According to some examples, the filter pad is formed of 98% 3 ply splash resistant filter foldable media (50gsms Needle-Punched+25gsms melt-blown+22gsms aim), or spun bond polypropylene ultrasonic welded pad. The filter pad bonds with the surface of the mask via a die cut, medical grade adhesive.

Air vents may provide a direction for air out of the mask to aid breathability, and can in some examples be oriented in the opposite direction to which the wearer is facing. Air vents can therefore direct breath from a user away from others, for example back onto the user's face. The mask thereby minimises the risks of transmission of a virus or bacteria from the user to others in front of the mask, while providing a transparent, breathable mask through which a user's mouth can be seen. This is useful when a user needs to communicate with people who rely on lip-reading.

In some examples, the use of air vents means the mask aids airflow, breathability, and reduces dangerous CO2 build up. This reduces the cost of the mask and means there is no air filter which could restrict the view of the user's mouth.

The face mask may comprise a sheet which forms the cover. The sheet may comprise a boundary, wherein in use the boundary of the sheet contacts a user's face. The or each air vent may be adjacent to the boundary of the sheet. The or each air vent may be at the boundary of the sheet. By placing the or each air vent adjacent and/or at the boundary of the sheet, the view of the user's mouth can be kept clear.

The sheet may form the or each air vent. The sheet forming the or each air vent means the cover and the or each air vent can be made of one body (the sheet), substantially simplifying and reducing the cost of manufacturing the face mask. According to some examples, the sheet may effectively form a casing (main body) 100 of the face mask, and the air vents may be built into the sheet.

The sheet may be transparent. The sheet being transparent minimises the face mask's interference with the entire area of the user's face which is covered, which allows others a better view of a user's expressions and therefore better communication.

The sheet may be plastic. The sheet may be a thermoplastic elastomer.

The face mask may comprise two or more air vents. The face mask may comprise three air vents. The face mask may comprise a plurality of air vents. The face mask comprising a plurality of air vents means the provided routes are less likely to all be blocked and prevent a user breathing.

The face mask may comprise a skirt at the boundary of the sheet. The skirt forms a better fit with a user's face, minimising the air which can escape from the mask via routes other than the vents At least part of the boundary of the sheet may be formed by the skirt and the one or more air vents. The boundary being formed by the skirt and the one or more air vents means there is no way, or few ways, for air to escape the mask other than via the vents.

The skirt may be formed by the sheet. The sheet forming the skirt means the manufacture of the face mask is simplified, since the skirt and cover are formed by one part. The face mask may be shaped to conform with a user's face. The boundary of the face mask may be shaped to conform with a user's face. The boundary of the face mask may sit closely, but not form a seal to the user's face. The skirt may be shaped to conform with a user's face. The face mask being shaped to conform to a user's face, i.e. the face mask being shaped to be a close-fit to a user's face, reduces and/or eliminates gaps between the user's face and the face mask when the mask is in use, minimising the amount of air which can escape the face mask other than via the air vents. The boundary and/or skirt being shaped to conform with a user's face minimises and/or eliminates these gaps further. As such, the mask is more comfortable to wear (especially for long periods) and does not interfere with the use or fogging of glasses.

The face mask may comprise one or more attachment straps operable to hold the face mask on a user's face. The face mask may comprise one or more pairs of attachment straps, wherein in use the attachment straps of the or each pair, hold the face mask on a user's face.

The use of one or more pairs of attachment straps means the face mask can be hooked around a user's ears to be held in place.

Having multiple air vents reduces the chances that all of the air vents will be blocked at the same time by the movement of a user's face, since movement towards one air vent (closing or restricting it) is movement away from one or more of the other air vents. In some examples there are two air vents, one adjacent the cheek on the right hand side of the user and one adjacent the cheek on the left hand side of the user.

The face mask may comprise an anti-fog additive. The inclusion of an anti-fog additive reduces the likelihood of the mask fogging up during use. The anti-fog additive may be built into the cover. Building the anti-fog additive into the cover reduces the chances the additive is removed during use or washing. Some examples of anti-fog additives are described below. The face mask may comprise an anti-microbial additive. The inclusion of an antimicrobial additive reduces the chances of transmission. The anti-microbial additive may be built into the cover. Building the anti-microbial additive into the cover reduces the chances the additive is removed during use or washing.

The skirt may extend outwards from an end of the cover. The skirt may extend from the end of the cover at an obtuse angle.

An opening of the or each air vent may be adjacent the boundary of the sheet. The or each opening may be at the boundary of the sheet. The or each air vent may be formed with the skirt.

The or each air vent may form a respective channel for air. The or each channel may be U-shaped. A bottom of the or each channel may be convex along its length. The or each air vent may be directed away from the centre of the cover. The or each air vent may be directed towards the boundary of the sheet.

The mask may have a bacterial filtration efficient media bonded to the underside of the mask to enable breathing filtration. This may be bonded by adhesive. The filter is designed to prevent the outward transmission of microorganisms, blood and body fluids and airborne particulates.

The face mask may be a medical or non-medical face mask.

FIG. 1 is an illustrative representation of a transparent facemask, in front view, in accordance with embodiments of the present invention.

Cover 100 Skirt 102 Air Vent 104 Filter pad 106 Attachment straps 108.

FIG. 2 is an illustrative representation of a transparent facemask, in front/side view, with filter pad separated from cover for clarity of features, in accordance with embodiments of the present invention.

Cover 200 Skirt 202 Air Vent 204 Filter pad 206 Attachment straps 208 Indentation/Lip provides attachment point for filter pad 210.

FIG. 3 is an illustrative representation of a transparent facemask, in front/side view, in accordance with embodiments of the present invention.

Cover 300 Skirt 302 Air Vent 304 Filter pad 306 Attachment straps 308 FIG. 4 is an illustrative representation of a transparent facemask, in side view, in accordance with embodiments of the present invention.

Cover 400 Skirt 402 Air Vent 404 Filter pad 406 Attachment straps 408 The facemask may be formed of TPE, silicone, rubber, polyurethane, polypropylene, polycarbonate, stainless steel, aluminum, ceramic, or any other variations known in the art. The manufacturing method of the facemask may make use of injection molding, rotational molding, compression molding, die casting, die cutting, ultrasonic welding, laser cutting, 3D printing, or any other variations known in the art.

The facemask may be formed of a non skin-safe or non medical grade material and then given a skin-safe or medical grade coating such as epoxy resin.

The facemask may have one air vent, two air vents, three air vents, or any other variations known in the art.

The facemask may be attached to the face via suction, a head strap, a neck strap, ear straps, or any other variations known in the art.

The facemask may be transparent, translucent, opaque, or any other variations known in the art.

Facemask Respirator A problem is that on average, the more effective a mask is at filtering the air and protecting the user, the larger and more cumbersome it is.

Many working professionals are required to wear large industrial level masks for long periods of time. While carrying out their professional duties they are still required to interact with co-workers, customers, or patients. Having a large and obstructive mask over the mouth impedes communication.

Smaller and lighter masks may be more comfortable and more convenient, but provide the user with less protection.

A further issue with a typical respirator is that it filters air entering into the mask, but it does not filter air leaving the mask. With the ongoing Covid-19 pandemic, it is important to filter air both entering and leaving a mask. This protects the wearer of the mask, as well as those around them in addition.

There is a need on the market for a simple and effective face mask respirator that provides high levels of air filtration while also facilitating better communication.

The invention may comprise an EN-1827 respirator with a transparent moulded plastic body and multiple filtration ports for both inhalation and exhalation.

The wearer of a respirator may need to communicate with the people around them, whether they are coworkers, customers, patients, etc. A transparent body of the respirator may give a view of the mouth of the user, even while wearing the respirator. It is a natural and automatic human ability to lip read while also listening to a person's voice. Being able to see the mouth of the respirator wearer greatly improves the ease and accuracy of any communication The respirator may have a single exhalation port and dual inhalation ports. In some examples, the respirator does not have or require inhalation valves. The inhalation ports filter air entering the mask to protect the user against airborne particles. The exhalation port filters air leaving the mask, to protect anyone in the immediate vicinity of the mask wearer. According to some examples, each of the exhalation ports and each of the inhalation ports are distinct (different) ports.

The assembly comprises a transparent face mask body with removable filter modules and additional replaceable exhalation filter. In some examples, the assembly consists of transparent face mask body with removable filter modules and additional replaceable exhalation filter. Within the exhalation pathway, the product comprises a one way valve that prevents the inlet of air during the inhalation phase. In some examples, within the exhalation pathway, the product consists of a one way valve that prevents the inlet of air during the inhalation phase In some examples, inhalation valves were not incorporated into the invention to aid airflow, and limit misting/fogging of the facemask body. The removal of inhalation valves helps the invention pass the CO2 requirements of EN-1827.

To use the product, the wearer may firstly attach the main filter modules to the facemask body via a bayonet fitting. The particulate filters may comprise or consist of a pleated filter pack with an overmoulded TPE gasket, and are secured within the modules via a series of interfering bump features and latch mechanism. The exhalation filter may be manufactured via a TPE gasket overmoulded to a filtration media disc which is secured via interference to the outer diameter of the associated port. A cap is then attached to the port via a bayonet fitting to secure the exhalation filter in place.

In some examples, the exhalation filter may be permanently attached to the exhalation port.

The invention may comprise a P3 grade mask with filtered exhalation. This is a new and unique application.

The mask material may be certified to EN 166 (7.3.2 Resistance to fogging (EN 168: 2001 Clause 16)).

In some examples, a key ingredient is an additive to the thermoplastic elastomer (TPE), polymer before the injection moulding process. The basic polymer is incorporated into a formulary (plastic compound) with specially formulated anti fog 'additive', which is a chemical compound, added to improve the performance.

The thermoplastic elastomer may be compounded with SABOOSTAT DELA/S to give the anti fog effect.

This enables the even spread of the effect, which is to prevent the condensation of water which creates fog. The technology works by changing the surface tension and subsequently flattens water droplets (which cause fogging), on the surface This antifog effect continues to work after multiple washing and sterilisation cycles (tested to 50 cycles so far) FIG. 5 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in front/side exploded view, in accordance with embodiments of the present invention.

Medium Facemask Overmould Sub-assembly 550 P3 Filter Sub-assembly 552 Left-hand Filter Module 554 Filter Cap 556 Exhalation Filter Subassembly 558 Exhalation Filter Body 560 Exhalation Filter Cap 562 Facemask Strap 564 Strap Buckle 566 Exhalation Port Gasket 568 Headband Support 570 Right-hand Filter Module 572 FIG. 6 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in front/side view, in accordance with embodiments of the present invention.

Medium Facemask Overmould Sub-assembly 650 Left-hand Filter Module 682 Filter Cap 684 Exhalation Filter Body 686 Exhalation Filter Cap 688 Facemask Strap 690 Strap Buckle 692 Headband Support 694 FIG. 7 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in front/side view, in accordance with embodiments of the present invention. The invention is an EN-1827 respirator 700 with a transparent moulded plastic body 702. The respirator has a single exhalation port 704 and dual inhalation ports 706. A head strap 708 secures the mask over the user's face.

FIG. 8 is an illustrative representation of a facemask respirator with transparent body and exhalation port, in rear view, in accordance with embodiments of the present invention. The invention is an EN-1827 respirator 800 with a transparent moulded plastic body 802. The respirator has a single exhalation port 804 and dual inhalation ports 806.

The respirator may be formed of TPE, silicone, rubber, polyurethane, polycarbonate, stainless steel, aluminum, ceramic, or any other variations known in the art.

The manufacturing method may make use of injection molding, rotational molding, compression molding, die casting, laser cutting, 3D printing, or any other variations known in the art The respirator may be formed of a non skin-safe material and then given a skin-safe coating such as epoxy resin.

The respirator may have one exhalation port, two exhalation ports, three exhalation ports, or any other variations known in the art.

The respirator may have one inhalation port, two inhalation ports, three inhalation ports, or any other variations known in the art.

The respirator may be attached to the face via suction, a head strap, a neck strap, or any other variations known in the art.

The respirator can be applied to P1 masks, P2 masks, P3 masks, or any other variations known in the art The respirator may be transparent, translucent, opaque, or any other variations known in the art.

Anti-foci thermoplastic elastomer additive and manufacturing process A solution to enable better communication is a face mask or respirator that is formed of a transparent material. This would enable a view of the lips through the mask while a person is speaking.

A problem is that fogging and misting are a common problem with plastics surrounding 14 the mouth. A human breath contains warm moist air. As a user breathes or speaks against a face mask or respirator, condensation occurs. This once again impedes the view of the mouth, and the problem remains.

Fogging is the phenomenon that is caused when water vapor condenses out of air (such as breathing) onto a solid surface. The surface may have desirable transparent characteristics that are then obscured. As water settles on a surface, droplets form which scatter light creating the fogging effect. The problem to retain transparency when it is subjected to breath over an extended period, occurs in all plastics, silicones, thermoplastics and elastomers Current solutions are coatings or surface treatments, applied after injection moulding by dip, spray, PVD (physical vapour deposition), CVD (chemical vapour deposition), and plasma treatments. These are secondary, time consuming processes and can be very expensive in specialist settings. There are hydrophilic and hydrophobic additives which offer temporary effectiveness, over a few days, or a single washing cycle.

Current Solutions A for anti fog Air flow for instance can be managed by building in air handling units into the mask design which has been achieved commercially by ExFog. The device is bulky and unwieldy but works to manage airflow by pumping exhaled breath away from the fogging surface.

Alternative solutions are to actively pump air near to the fogging surface, the temperature will then need to be managed by localised heating of the fogging surface. This could be achieved in technological analogues to heated car windscreens; substituting glass for polymer layers which are then used to encapsulate a transparent resistive heating layer. Development of this kind of technology is also expensive to perform and not especially suitable for lightweight, low cost face masks.

There is a method for making a fog resistant thermoplastic by conditioning a thermoplastic article by exposing it to an aqueous environment sufficient to result in fog resistance (US Patent US7731881B2). This is for polycarbonate which has a different molecular structure and is more expensive to manufacture, than TPE.

The last method that can be used is to manage humidity. This can be done using a simple sink, such as a desiccant, or a more advanced design using a transparent plastic sink which can be positioned in line with the surface requiring protection. A commercial example of this is the pinlock motorcycle helmet insert. This is a plastic absorbent transparent material that sits on the helmet visor. It is raised from the visor by a silicon seal which works to create a double-glazing effect, insulating it from the external visor which will help to keep it less cold. The primary function, however, is to absorb moisture from any breath that hits it. It is not a perfect application as there are situations when it can fail, such as extremes of temperature, and saturation of the sink.

Current Solutions B for anti foq The second route of managing this problem is modification of the droplet behaviour as it forms on the surface. Contact angle is a main factor in determining the behaviour of a liquid on a surface. Larger contact angles create more spherical drops and thus more scattering of visible light. Anti-fogging agents are chemicals which when applied either reduce the contact angle to facilitate complete wetting (super hydrophilic, hydrophilic) or increase the contact angle (superhydrophobic, hydrophobic) to increase the chance of droplets rolling off the surface before significant fogging occurs. In either case this route relies on either modification of the surface energy (increasing it to produce better wetting, decreasing it to increase contact angles) or surface roughness. Hydrophobic surfaces are defined when its static water contact angle is >90° and is hydrophilic when it is <90°.

In summary, the current solutions are generally time intensive and expensive to produce. There is a need on the market for a simple solution that can be applied to transparent face masks and respirators in an economically viable way.

Anti Foci additive Solution According to some embodiments of the invention, an additive and manufacturing 16 process that produces a plastic used to prevent fogging/misting in a transparent face mask or transparent respirator is provided.

Design Abled (t/a Helloface) is developing a face mask (PPE -personal protective equipment), made from thermoplastic elastomer (TPE) called styrene-ethylene-butylene-styrene (SEBS). Transparency is a feature of the mask which is designed so that face to face interactions are not impeded by wearing it.

The thermoplastic elastomer (TPE) may be compounded with Antioxidant/stabilizer additive such as Diethanol amide, Anti-stat Additive for plastics, or N,N-bis(2-hydroxyethyl) dodecanamide for industrial plastic manufacturing to give an anti fog effect The additive may be added to the thermoplastic elastomer (TPE) polymer before the injection moulding process.

The basic polymer may be incorporated into a formulary (plastic compound) with specially formulated anti fog 'additive', which is a chemical compound, added to improve the performance.

This anti fogging technology being integrated into the material itself enables the even spread of the effect, which prevents the condensation of water that creates fog. This is called a hydrophilic effect. The technology works by changing the surface tension and subsequently flattens water droplets (which cause fogging), on the surface.

The anti fog additive may be added to the plastic using a pelletising extruder, also called a forming extruder. This machine generates plastic pellets that can then be used in the standard injection moulding process.

An example manufacturing process for adding the anti fog additive to TPE is as follows: 1) Preparing Additive such as Antioxidant/stabilizer additive, or Diethanol amide, or Anti-stat Additive for plastics, or N,N-bis(2-hydroxyethyl) dodecanamide or similar for industrial plastic manufacturing 2) Mixing and manufacture base polymers and additive, using industry standard methods, such as twin extrusion process or similar 3) Put base polymer in the extruder, to melt and propel forward inside the barrel of the extruder.

4) Add anti fog additives along the length of the barrel and mix into the base polymer 5) The materials are fully mixed by the time they reach the end of the barrel and are then turned back into plastic pellets ready to be used to make end products.

Transparent thermoplastic elastomer (TPE) that is produced using these additives and manufacturing processes does not fog/mist up when a person breathes on its surface.

This anti fog effect continues to work after multiple washing and sterilisation cycles (tested to 50 cycles so far).

The mask material is certified to EN 166 (7.3.2 Resistance to fogging (EN 168: 2001 Clause 16)).

FIG. 9 is an illustrative representation of an anti-fog thermoplastic elastomer additive and manufacturing process, as a system diagram, in accordance with embodiments of the present invention. The system diagram 900 shows the process of mixing the additive to the base polymer (TPE) using a pelletising extruder. The resulting pellets can be used to mass produce transparent face masks and respirators that will have anti fog benefits. The masks will have a natural resistance to fogging/misting as a wearer breathes on them.

The invention may be formed of or make use of TPE, silicone, rubber, polyurethane, polycarbonate, stainless steel, aluminum, ceramic, or any other variations known in the art.

The manufacturing method may make use of pellefising extruders, forming extruders, or any other variations known in the art.

The invention may be formed of a non skin-safe material and then given a skin-safe coating such as epoxy resin The invention material may be transparent, translucent, opaque, or any other variations known in the art.

The invention material has many applications for preventing fogging/misting and may be used in industries such as face masks, respirators, helmets, goggles, PPE, diving apparatus, swimming apparatus, or any other variations known in the art.

The pelleted form of the invention material may be used for injection molding, rotational molding, compression molding, producing 3D printing filament, or any other variations known in the art.

The invention may be transparent, translucent, opaque, or any other variations known in the art.

Figure 10 shows an example of face mask. The face mask may be broadly similar to the face mask described above with respect to figures 1 to 4. The face mask comprises a cover 1000 and also comprises two attachment straps 1008a and 1008b. The size of the attachment straps 1008a and 1008b can be adjusted. This can be useful to secure the attachment straps to the ears of a user.

The attachment straps 1008a and 1008b can have their size adjusted using a fastening mechanism. The fastening mechanism may comprise fasteners (which in some examples, may comprise notches) that are passed through a loop by a user to adjust the size of the attachment straps. In the example of Figure 10, fasteners 1032a and 1032b of attachment strap 1008a pass through loop 1030 Figure 11 shows a side view of the mask of Figure 10.

It will of course be understood that the examples described are by way of example only and are not intended to limit the scope of the invention The Figures are schematic in nature and not necessarily drawn to scale. It will be further understood that aspects of the described examples can be combined in any way.

Claims

CLAIMS1. A facemask respirator comprising: a facemask body; at least one inhalation port configured to filter air entering the respirator; at least one exhalation port configured to filter air leaving the respirator; a replaceable exhalation filter securable to the at least one exhalation port.
A facemask respirator according to claim 1, wherein the facemask body is transparent.
3. A facemask respirator according to claim 1 or claim 2, wherein an exhalation pathway through the at least one exhalation port comprises a one-way valve that prevents the inlet of air during inhalation of a user.
4. A facemask respirator according to any preceding claim, the facemask respirator comprising: a further filter module attached to the facemask body at the at least one inhalation port.
5. A facemask respirator according to claim 4, wherein the further filter module comprises a pleated filter pack with an overmoulded thermoplastic elastomer gasket.
6. A facemask respirator according to claim 4 or claim 5, wherein the exhalation filter comprises a thermoplastic elastomer gasket overmoulded to a filtration media disc.
7. A facemask respirator according to any of claims 4 to 6, wherein the further filter module is attachable to the facemask body at the at least one inhalation port using a bayonet fitting and wherein the second filter module is attachable to the facemask body at the at least one exhalation port using a bayonet fitting.
8. A facemask respirator according to any of claims 4 to 7, the facemask respirator comprising: a cap configured to be attached to the at least one exhalation port to secure an exhalation filter of the second filter module in place.
9. A facemask respirator according to any preceding claim, wherein the facemask body comprises an anti-fog additive.
10. A facemask respirator according to claim 9, wherein the facemask respirator is formed of a thermoplastic elastomer.
11. A facemask respirator according to claim 10 when dependent on claim 9, wherein the anti-fog additive and the thermoplastic elastomer are compounded together.
12. A facemask respirator according to any preceding claim, wherein the facemask respirator comprises an EN-1827 respirator.
13. A facemask respirator according to any preceding claim, wherein the at least one inhalation port comprises two inhalation ports.
14. A facemask respirator according to any preceding claim, wherein the exhalation filter is securable to the exhalation port using a thread on the exhalation filter and a thread on the exhalation port.
15. A facemask respirator according to any of claims 1 to 13, wherein the exhalation filter is securable to the exhalation port via an interference fit.