Face mask

Abstract

A face mask comprising: a window section comprising a first material, wherein the first material is transparent and treated with an anti-fog solution, and wherein the window section is configured to overlap with a mouth of a wearer of the face mask when the face mask is worn such that the mouth of the wearer is visible when the face mask is worn; a second section comprising a second material that is more flexible than the first material, wherein the second section surrounds a perimeter of the window section and wherein the second section comprises a lip section for making contact with the wearer when the face mask is worn.

Description

FACE MASKTECHNICAL FIELD

[0001] The present disclosure relates to a face mask and a method of making such a face mask.BACKGROUND

[0002] In recent times, the global population has experienced unprecedented challenges due to the prevalence of respiratory infections and pandemics such as COVID-19. The use of face masks has become a ubiquitous practice to mitigate the spread of airborne pathogens, providing a crucial line of defence in various environments.

[0003] However, the widespread adoption of traditional masks has led to a significant challenge such as communication barriers and loss of emotions expressed during conversation. Conventional masks, while effective in preventing the transmission of respiratory droplets, can obscure facial expressions and / or muffle speech. This limitation poses obstacles in various sectors, including healthcare, education, and everyday interactions.

[0004] US20230285782A1 discloses a high-filtration reusable face mask. The manufacturing process involves a single injection mold, with the textured contact area receiving a specific finish, while the non-textured region is polished to ensure optical clarity. The mask, designed as a single-piece structure covering the nose and mouth, features a filter attachment port with a coupling mechanism for connecting to a replaceable filter. Additionally, the mask includes a user-facing textured rim

[0005] US20220339472A1 discloses high-filtration reusable face masks with replaceable filters and a single-piece mask body designed to cover the nose and mouth. The masks include at least one filter attachment port with a filter support structure, facilitating the connection to replaceable filters. This attachment port aids in supporting the replaceable filter by separating portions of the filter media when attached. The face mask body, in certain embodiments, is formed as a single piece through injection molding, with a nosepiece made of bendable metal positioned to align with the user's nose bridge for a personalized fit, ensuring better protection and comfort.

[0006] W02023099904A1, describes a face mask designed to filter airborne particles and covers the nose, mouth, and chin area of the wearer's face. It incorporates at least one aperture tofacilitate airflow and includes a sealing mechanism for a snug fit around these facial areas. The mask features filters arranged over the aperture(s) to filter incoming air. The manufacturing process involves injection molding, making the cover portion a thermoplastic polyurethane (TPU) material in exemplary embodiments.SUMMARY OF THE DISCLOSURE

[0007] According to a first aspect, there is provided a face mask comprising: a window section comprising a first material, wherein the first material is transparent and treated with an anti-fog solution, and wherein the window section is configured to overlap with a mouth of a wearer of the face mask when the face mask is worn such that the mouth of the wearer is visible when the face mask is worn; a second section comprising a second material that is more flexible than the first material, wherein the second section surrounds a perimeter of the window section and wherein the second section comprises a lip section for making contact with the wearer when the face mask is worn.

[0008] According to some examples, the second material is not treated with the anti-fog solution.

[0009] According to some examples, the second material is translucent.

[0010] According to some examples, the first material comprises polyethylene terephthalate glycol, PETG.

[0011] According to some examples, the first material comprises polycarbonate, PC.

[0012] According to some examples, the anti-fog solution comprises polyurethane.

[0013] According to some examples, the second material comprises thermoplastic elastomer, TPE.

[0014] According to some examples, the second section provide a base structure of the face mask, excluding a cavity in which the window section is positioned.

[0015] According to some examples, the window section is over-molded onto the second section.

[0016] According to some examples, the face mask comprises a face mask respirator.

[0017] According to some examples, the face mask comprises a filter port in which reuseable filter pads can be placed.

[0018] According to a second aspect, there is provided a method of manufacturing a face mask comprising: injection molding or vacuum forming a window section of the face mask, wherein the window section comprises a first material that is transparent and treated with an antifog solution; injection molding or vacuum forming a second section of the face mask, wherein the second section comprises a second material that is more flexible than the first material; integrating the window section of the face mask onto the second section of the face mask such that the second section surrounds a perimeter of the window section, wherein the window section is configured to overlap with a mouth of a wearer of the face mask when the face mask is worn such that the mouth of the wearer is visible when the face mask is worn and wherein the second section surrounds a perimeter of the window section .

[0019] According to some examples, the integrating comprises an over-molding process.

[0020] According to some examples, the second section comprises a base structure of the mask with a cavity for integrating the first window section.

[0021] According to some examples, the window section matches contours of the cavity.

[0022] According to some examples, the method comprises trimming at least one of: the window section; and the second section.

[0023] According to some examples, the second material is not treated with the anti-fog solution.

[0024] According to some examples, the second material is translucent.

[0025] According to some examples, the first material comprises polyethylene terephthalate glycol, PETG.

[0026] According to some examples, the first material comprises polycarbonate, PC.

[0027] According to some examples, the anti-fog solution comprises polyurethane.

[0028] According to some examples, the second material comprises thermoplastic elastomer, TPE.

[0029] According to some examples, the second section provide a base structure of the face mask, excluding a cavity in which the window section is positioned.

[0030] According to some examples, the face mask comprises a face mask respirator.

[0031] According to some examples, the face mask comprises a filter port in which reuseable filter pads can be placed.

[0032] According to a third aspect, there is provided a method for manufacturing a transparent respiratory mask for enhanced communication features, comprising the steps of: custom injection molding or vacuum forming of a clear plastic window using Silicone or thermoplastic materials such as PET, BOPET, RPET, APET, PC, TPE, or TPU pre-treated with anti-fog solution that is indelible, non-removable or permanent, to match the contours of the injection-molded mask; injection molding a base structure of the respiratory mask, excluding a designated front section; integrating the clear plastic window onto the front of the mask using a proprietary over molding process; conducting material flow analysis to optimize temperature, pressure, and flow rate for uniform material distribution during over molding; designing the mold to include filter ports and accurately replicate the periphery of the respiratory mask; developing a tool setup for localized gripping to ensure stability during over molding; incorporating edging positions and feeds in the mold for encapsulating the edges and ports; implementing a trimming process to precisely trim the formed material, including filter ports and periphery; subjecting the formed material to injection molding or vacuum forming to shape it to the desired mask shape; transferring the shaped material to an injection molding tool; over molding the transparent window onto the mask, allowing for curing and cooling to achieve a seamless integration.

[0033] According to some examples, the materials used for the clear plastic window are selected based on their transparency, anti-fog properties, and compatibility with respiratory mask requirements.

[0034] According to a fourth aspect there is provided a respiratory mask with enhanced communication features, comprising: a base structure injection-molded from a suitable material; a clear plastic window seamlessly integrated onto the front of the mask using a proprietary over molding process; said clear plastic window formed through custom injection molding or vacuum molding using Silicone or thermoplastic materials such as PET, BOPET, RPET, APET, PC, TPE, or TPU pre-treated with anti-fog solution that is indelible, non-removable or permanent; filter ports designed into the mask for compatibility with various respiratory mask types; material thickness optimized to support the over molding process while ensuring structural integrity; transparent window exhibiting anti-fog properties for clear visibility during usage; an adaptable design suitable for respiratory masks including Pl, P2, P3, transparent alternatives to surgical masks, anesthetic masks, and powered respirators; edging positions and feeds encapsulating the edges andports for a secure integration of the transparent window; a final form achieved through a trimming process, ensuring precision and consistency across products.BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0036] The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:

[0037] Fig. 1 shows an example of a respiratory protective mask with a transparent and anti-fog window;

[0038] Fig. 2 shows a second view of the mask of Fig. 1, where the exhalation and inhalation filter caps have been removed; Fig. 3 shows a second mask having a transparent and anti-fog window;

[0039] Fig. 4 shows a mold that can be used to provide a transparent and anti-fog window for a mask;

[0040] Fig. 5A shows an example mask window section that can be formed using the mold of Fig. 4;

[0041] Fig. 5B shows the example mask window section of Fig. 5 after a trimming process;

[0042] Fig. 6 shows an example method for providing a mask;

[0043] Fig. 7 shows an example method for providing a mask.DETAILED DESCRIPTION OF DRAWINGS

[0036] Some examples described herein relate to face masks. Some particular examples are designed to overcome communication barriers while preserving the efficacy of respiratory protection.

[0037] Typical facemasks obscure a user’s face, which can reduce the quality of communication between the mask wearer and third parties. Even transparent masks can obscure a wearer’s communication with a third party, as transparent masks are typically prone to foggingfrom the wearer’s breath. Maintaining clear communication is useful in healthcare settings, educational institutions, and social interactions. Individuals wearing masks, particularly those with hearing impairments or relying on lip-reading, face increased difficulties in understanding spoken language.

[0038] During medical scenarios such as surgery where a mask is required to be worn to reduce the risk of infection, but loud equipment may make it difficult for co-workers to hear each other, being able to see that a co-worker is talking or trying to communicate can improve safety.

[0039] Further, in industrial scenarios where workers are required to wear a mask to avoid breathing particulates or dangerous chemicals, loud machinery or hearing protection (e.g., industrial hearing protection) make it difficult for co-workers to hear each other. Examples described herein provide a mask that can be worn in such a scenario which prevents a wearer’s mouth being obscured while worn. This is particularly useful to enhance safety in an industrial scenario to enable quick communication between mask wearers when wearers are required to communicate quickly (e.g. if equipment fails) but the mask wearers are not able to easily hear each other due to loud machinery and / or due to safety equipment such as hearing protection.

[0040] Some examples involve the incorporation into a mask of a specialized silicone or thermoplastic material. Such materials may comprise polyethylene terephthalate (PET), PET modified with glycol (PETG), biaxially orientated polyethylene terephthalate (BOPET), recycled polyethylene terephthalate (RPET), amorphous polyethylene terephthalate (APET), polycarbonate (PC), thermoplastic elastomer (TPE), or thermoplastic polyurethane (TPU).

[0041] In some examples, at least some of the materials of the mask may be pre-treated with anti-fog solution. The anti-fog solution may comprise polyurethane, PU, or other suitable anti-fog solutions. The anti-fog solution and the pre-treatment may provide a material which has anti-fog properties that are long-lasting such that a user of the mask does not experience fogging of at least part of the mask for a long period of time (e.g., months or years). In some examples, the anti-fog properties may be such that the anti-fog properties are provided for the lifetime of the mask.

[0042] In some examples, the anti-fog may be applied as a coating to a window section of the mask. The coating may comprise amphiphilic compounds in some examples, such that the coating has both hydrophobic and hydrophilic regions.

[0043] In some examples, a hydrophilic anti-fog coating may be used. In some examples, nanoscale hydrophilic bonds can be used to create a highly hydrophilic functionalised surface. The hydrophilic coatings may be based on polysiloxane, polyurethane or polyacrylamide, for example, and can be bonded to the surface of an anti-fog window of the mask.

[0044] The transparent masks described herein may comprise an anti-fog and transparent section at the front of the mask, positioned to align with a user’s mouth when worn. In some examples, the anti-fog and transparent section may comprise an over-mold material in front of a mask cavity. As such, fogging of the mask cavity, which may be positioned over a user’s mouth, is avoided. This provides a transparent and anti-fog “window” in the mask such that a wearer’s mouth is not obscured during communication. This removes the communication barrier that can be caused by a user’s mouth not being visible while talking or making expressions, without compromising the security of having masked protection. In some examples, the over-mold material coated with the anti-fog solution forming the transparent window can be over molded in a multi- step injection molding process, molding over the top of the respiratory mask, which has a window space cavity, joining the two components.

[0044] In some examples, the transparent, anti-fog material may first go through injection molding or vacuum forming process to match the shape of the mask. Thermoforming can be used, where a plastic sheet is heated and formed over a mold. The mask can then be injection molded, excluding a designated section. The designated section can be excluded by blocking this section out during injection molding, or by operating the injection molding machine accordingly. As such, the mask is produced with a specifically designed window for an anti-fog sheet to be inserted and overmolded to the main body of the mask. This window section may later be filled with the transparent anti-fog material, for example by an over-molding process. The feature utilises an injection molding or vacuum forming process performed earlier, to match the contours of the injection- molded mask. This process provides the integration of the transparent window onto the respiratory mask without any gaps between the two components, preventing fogging and maintaining visibility.

[0045] In some examples, the anti-fog material may be the same as those shown to be effective in preventing fogging in diverse applications such as glass shower doors, freezer doors, and refrigerator doors.

[0046] The mask described herein, with its transparent anti-fog window, may be used in sectors like healthcare, education, and social interactions. In some examples, the modified mask undergoes testing to test at one or more of the durability, anti-fog effectiveness, and safety of the mask for widespread use.

[0047] The invention addresses the communication challenges posed by opaque and translucent respiratory masks (Pl, P2, and P3 - where Pl, P2, and P3 describe the level of filtering protection provided by the mask - transparent alternatives to surgical, anaesthetic, and powered respirator masks).

[0048] In some examples, by incorporating an over molding process, a transparent plastic window may be integrated into the front of the mask. The over molding technique, which uses injection molding, ensures a secure attachment of a transparent plastic window to the mask's front, enabling visibility without compromising mask protection. The over molding material may comprise Silicone or thermoplastic materials including PET, PETG, BOPET, RPET, APET, PC, TPE, or TPU. These materials display anti-fog properties and therefore may be applicable to a range of respiratory masks, including Pl, P2, P3, transparent alternatives to surgical masks, anaesthetic masks, and powered respirators. The additional over molding step, using silicone or thermoplastic materials pretreated with anti-fog solution, in the production of the modified mask ensures that the modified mask is durable, flexible, and transparent.

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the following describes some examples with reference to accompanying drawings All other embodiments obtained by a person of ordinary skill in the art based on embodiments of this application without creative efforts shall fall within the protection scope of this application.

[0050] Fig. 1 and 2 show an example of a mask respirator having a transparent and antifog window that can be used for communication. Fig. 3 shows a mask having a transparent and anti-fog window.

[0051] The example mask respirator shown in Fig. 1 and 2 can be configured to be a sustainably designed Respiratory Protective Equipment (RPE). The Mask Respirator may be UK Conformity Assessed (UKCA) and European Conformity (CE) certified, meeting the British Standards Institution (BSI) standards (EN 1827:1999). The body of the respirator may conform to the EN 140:1998 standard. The mask may be NIOSH (National Institute for Occupational Safety and Health) approved. The respirator may be applicable to various industries, from healthcare toconstruction, including chemical processing, painting, healthcare, oil and gas, construction, food safety, manufacturing, health and safety, pharmaceuticals, agriculture, and waste management.

[0052] Fig. 1 and Fig. 2 shows an example mask 100, from a perspective view and from a front view respectively. Mask 100 may comprise a facemask respirator. Mask 100 comprises an exhalation port 104 and inhalation ports 106a and 106b. It should be noted that different examples may have different numbers of inhalation and exhalation ports, and that they may be positioned differently to the illustrative example of Fig. 1.

[0053] In Fig. 1, an exhalation filter cap is connected to exhalation port 104 and inhalation filter caps are connected to inhalation ports 106a and 106b. In Fig. 2, the exhalation cap and inhalation caps are removed to show the interior section 112 of the exhalation port 104 and to show the interior sections 114a and 114b of the inhalation ports 106a and 106b.

[0054] Mask 100 comprises a transparent and anti-fog section 102 that is positioned to align with a wearer’s mouth when the mask is worn. Mask 100 comprises a second section 108 that may be made of a different material to section 102. The second section 110 also comprises a lip section 110 for contacting a wearer’s face. The top of the lip section 110 is configured to make contact with the bridge of a wearer’ s nose, while the lower portions are configured to make contact with the wearer’s cheeks and jaw.

[0055] The first “window” section may have an anti-fog solution applied to it, while in some examples the second section 108 does not have an anti-fog solution applied. By not applying anti-fog solution to the entire body of the mask, less energy is required to be used in the preparation of the mask materials. Further, the anti-fog performance of section 102 is improved, as condensation from the user’s breath is allowed to settle and cause fogging on the second section 108 while being drawn away from section 102. This does not significantly affect the ability of third parties to see a user’s facial expression when the mask is worn, as the second section 108 is not configured to align with a user’s mouth, in contrast to section 102 that is configured to align with a user’s mouth. Most a user’s communication is expressed via movements of the mouth, so focusing the anti-fog properties of the mask on keeping section 102 transparent and unobscured (i.e., not fogged or misted over) provides the most benefit during communication.

[0056] Different materials can be used for the two different sections 102 and 108. A softer, more flexible material can be used for section 108. This allows section 108, in particular the lip 110, to conform to a wearer’s face comfortably. This also allows section 108 to conform to auser’s face to create an air-tight, or substantially air-tight, seal where lip 110 contacts the wearer’s face. By using different materials for the two sections 102 and 108, this also allows selection of a material for section 102 that has suitable properties for applying an anti-fog solution to the material. It has been found that such materials are harder and less flexible than would be desirable for section 108.

[0057] In an example, section 102 may comprise a PETG material treated with an anti-fog solution. This material has been found to provide good transparency and can be treated with an anti-fog solution. In some examples, the anti-fog solution may comprise polyurethane, which has bene found to attach well to the surface of a PETG material. It should be noted that if the entire mask 100 was made of PETG, section 108 would not provide suitable flexibility for the lip section to conform to a user’s face, as PETG is not sufficiently flexible. Section 108 may comprise TPE. This material can provide a good seal for lip 110 to conform to a user’s face, as TPE is suitably flexible. It should be noted that it is more difficult to apply anti-fog solution to TPE than to PETG, and TPE material is less transparent than PETG, and as such using TPE for all of mask 100 would not improve communication as well as using treated PETG for section 102.In some examples, through an over molding process, transparent plastic window 102 can be integrated in a cavity of mask 100, the transparent plastic window being injection molded over the top of the cavity to attach it, replacing the front of the mask and rendering it transparent. As discussed above, this modification enhances visibility without compromising the mask's structural integrity by integrating a clear plastic window onto the front of the mask through the over molding process The transparent window may be made from Silicone or thermoplastic materials including PET, PETG, BOPET, RPET, APET, PC, TPE, or TPU, allowing visibility through the transparent window without compromising the structural integrity of the mask. The manufacturing process and material selection may be applicable to various respiratory masks, including Pl, P2, P3, transparent alternatives to surgical masks, anaesthetic masks, and powered respirators. In an example, glass material treated with an anti-fog solution may be used for section 102 instead of plastic.

[0058] In some examples, the transparent window may be formed of Polycarbonate (PC) treated with an anti-fog solution. PC has a higher distortion temperature than PETG, and can be decontaminated with traditional hot water washing at approximately 90C. Anti-fog solution of PU can be used, or any of the other anti-fog solutions disclosed herein.

[0059] In some examples, TPE material could be used to provide the window section as well as the mask body section. Vacuum deposition of metal oxides or deposition of organometallic could be used so that the TPE window has anti-fog properties.

[0060] In some of examples described herein, anti-fog protection can be generated from polyurethane or polysiloxane based coatings. These can be applied to a variety of substrates for the material of the anti-fog window, such substrates including polycarbonate, acrylic, Nylon or PETG. In some examples, a primer or adhesion promoter can be used to coat the substrate with the anti-fog solution to the substrate. In some examples, anti-fog coatings can be applied using could be applied using dip, flow, and spin techniques.

[0061] An illustrative example is provided for insights into measurements for different sections of a face mask design. The soft return areas of lip 110, designed to conform comfortably to the face, measure approximately 0.99mm. The main wall sections (e.g., section 102 and the nonlip sections of section 108), which contribute to the overall structural integrity, have a thickness of approximately 2mm. Additionally, there is a thicker section around the filter ports 106a, 106b and 104, measuring approximately 4.025mm, indicating a robust construction in that particular region. These features, e.g., the filter ports, may be integrated during the initial molding process or added subsequently. The mask may be produced with a specifically designed window for an anti-fog sheet to be inserted and overmolded to the main body of the mask. In order to be over-molded, the anti-fog coated sheet can be loaded into a specific window area reserved for the clear anti fog material, during the molding process. The sheet may be vac-formed into a specific shape before over-molding. In some examples, the sheet comprises a PETG material treated with anti-fog (e.g., PU). In some examples, the sheet comprises PC treated with anti-fog. Furthermore, in both scenarios, where the vac-forming is either loaded into the cavity or the material is fitted to the core, there can be an emphasis on encapsulating the edges of the clear PETG or PC (or other suitable clear plastic) with TPE. This encapsulation process ensures a secure and integrated assembly of different materials into the face mask design.

[0062] Fig. 3 shows a second example mask 300 relative to a user’s face. Similar to mask 100, the mask comprises a transparent and anti-fog section 320, which may be used as a window through which the user’s mouth can be seen. Mask 300 may also comprise a second section 324, which may be made of a different material to section 320. It should be noted that although Fig. 3 shows section 324 only being the lip of mask 300, in other examples section 324 may comprise aportion of the body of mask 300 such that section 324 is part of the convex body of mask 300 and surrounds section 320.

[0063] Mask 300 may also comprise a filter port 322, in which replaceable filter pads can be used.

[0064] Similar to mask 300, different materials can be used for the two different sections 320 and 322. A softer, more flexible material can be used for section 322, allowing section 322 to conform to a wearer’ s face comfortably and in an air-tight, or substantially air-tight, seal with the wearer’s face. The material of section 320 can have suitable properties for applying an anti-fog solution to the material.

[0065] In an example, section 322 may comprise a PETG material treated with an anti-fog solution. This material has been found to provide good transparency and can be treated with an anti-fog solution. In other examples, section 322 may comprise PC treated with an anti-fog solution. In some examples, the anti-fog solution may comprise polyurethane, which has bene found to attach well to the surface of a PETG material. Section 322 may comprise TPE. This material can provide a good seal to conform to a user’s face, as TPE is suitably flexible.

[0066] Examples described below relate to example methods of how a mask (e.g., mask 100 or mask 300) may be manufactured. It should be noted that these are example methods only and other methods may be used to provide the masks described herein.

[0067] Fig. 4 shows a mold 400 that can be used to provide a transparent anti-fog window (such as sections 102 or 320 described in the above figures). Mold 400 can be used during a vacuum forming process or during injection molding of a material to provide a mask conforming to the shape of protrusion 430 (or its corresponding cavity on the opposite side of mold 400). In some examples, the material used is PETG treated with an anti-fog solution (e.g., polyurethane). In other examples, section 322 may comprise PC treated with an anti-fog solution (e.g., polyurethane treated with anti-fog solution). The anti-fog solution may be applied to the material of the window section before or after the vacuum forming / inj ection molding process used to provide the shape of the window section. It should be noted that the shape shown for protrusion 430 is for illustration only, and that other shapes are possible.

[0068] Fig. 5A shows an example window section that can be provided using mold 400 and vacuum forming or injection molding. In some examples, this provides a window section having a perimeter section 534 due to “overspill” during the vacuum forming or injection moldingprocess. This perimeter section can be removed using a trimming process, for example by using a Computer Numerical Control (CNC) machine to provide trimmed window section 536 shown in Fig. 5B.

[0069] Fig. 6 shows an example process for producing a mask with a transparent anti-fog window, that can be used to improve the quality of communication with the mask wearer.

[0070] At 642, a mold design for a base structure (which may be a substrate) of the mask is provided. Using injection molding or vacuum forming a material may be used to provide the mask with a front cavity at 646. The front cavity may be provided by controlling an injection molding machine appropriately or by blocking the injection molding, for example. The material may be soft and flexible such that it conforms to a wearer’s face. The material may be plastic or rubber. In some examples, the material is TPE.

[0071] At 640, a mold design for a mask window is provided. This may be similar to mold 430 of Fig. 4, for example. Using injection molding or vacuum forming a material can be used to provide a mask window section, such as mask window section 532 described above. The material may be different to the material used to provide the mask at 646 described above. In some examples, the material used for the mask window is less flexible than the material used for providing the base structure of the mask. In some examples, the material is a PETG treated with an anti-fog solution (e.g., PU). . In other examples, section 322 may comprise PC treated with an anti-fog solution (e.g., PU).

[0072] After 644 or 646, an optional trimming stage may be performed to ensure that the base structure of the mask or the mask window section is a desired shape (e.g., after 644, trimming may be used to provide the trimmed mask window section 536). This could be performed by cutting using a CNC machine, for example.

[0073] Using an over-molding process, the transparent window section can be over-molded on to the mask with the front cavity provided at 646. In some examples, the window section is formed first as shown at 644, and then over-molded on to the base structure of the mask. In other examples, the window section may be formed directly on to the mask with the front cavity (the base structure) during the over-molding process. The mask with a transparent and anti-fog window is then provided at 648.

[0074] A further example manufacturing process with additional detail is now provided for further illustration, process initiates with injection molding of the mask's base structure, excludinga designated front section where the transparent window will be integrated. An injection molding or vacuum forming process is employed to shape and mold a clear plastic window that matches the contours of the injection-molded mask.. An over molding process that uses the mask’s base structure as a substrate integrates the clear plastic window onto the front of the mask. This is performed by injection molding the clear plastic window over the top of the front of the mask, creating a unified structure that maintains structural integrity and functionality. The transparent and Anti-Fog Materials that may be used comprise Silicone or thermoplastic materials including PET, PETG, BOPET, RPET, APET, PC, TPE, or TPU pre-treated with anti-fog solution. The antifog solution is long-lasting so that the mask may experience the anti-fog properties for the duration of the mask’ s life span. The transparent and anti-fog materials are chosen for their transparency, durability, and anti-fog properties. These materials are tested for this application. In a particular example, the mask’s base structure is a TPE material and the window is a PETG material treated with PU. In another particular example, the mask’s base structure is a TPE material and the window is a PC material treated with PU. The transparent window allows visibility of the mouth through the transparent window, addressing communication challenges, while preventing fogging. The over molding process may be used to provide a range of masks, not only those shown in Fig. 1 to 3.

[0075] A testing phase can be carried out to ensure durability and longevity of the modified mask. This includes assessments of the materials' resistance to wear and tear under various conditions. Testing is carried out to confirm the anti-fog properties of the materials, ensuring visibility during use.

[0076] Fig. 7 is a flowchart for an example process of manufacturing 700 of a P3 protection half mask respirator.

[0077] At Step 702, Material Thickness Determination for Over molding: In the initial stage of the manufacturing process, an appropriate transparent and anti-fog material is selected. This material may comprise Silicone or thermoplastic materials including PET, PETG, BOPET, RPET, APET, PC, TPE, or TPU pre-treated with anti-fog solution that is long-lasting, where long- lasting means that the mask may experience the anti-fog properties for the duration of the mask’s life span. Material testing is conducted to determine the optimal thickness required to support the over molding process. This involves an assessment of factors such as durability, flexibility, and compliance with safety standards, ensuring that the chosen material meets the necessary criteria.In some examples, the thickness is approximately 1mm. Clarity and acoustics reduce as material thickness increases. If the material is too thin, its lack of weight and rigidity can stop it remaining in the right position during the over-molding process

[0078] At Step 704, Mold Design with Filter Ports and Periphery: The mold design phase creates a structure that replicates the periphery of the respiratory mask and incorporates ports for filters so that the ports do not cover the mouth area. This design ensures compatibility with various types of respiratory masks, maintaining the integrity of the mask while accommodating the transparent window. This design, where the ports for filters do not cover the mouth area, also ensures that lips and expressions are visible once manufactured.

[0079] At Step 706, Tool Design Setup for Gripping Mechanism: To ensure stability during the over molding process, a tool design setup is established to grip the formed shape. Attention is given to areas that are to be molded, optimizing the gripping mechanism for control and stability during subsequent manufacturing steps.

[0080] At Step 708, Material Flow Control Analysis: Comprehensive flow analysis is conducted to optimize the material flow during the over molding process. Parameters such as temperature, pressure, and flow rate are fine-tuned to ensure an even and secure grip, preventing any inconsistencies in the integration of the transparent window onto the mask. Inconsistencies in the integration may impact the quality of the seal.

[0081] At Step 710, Edging Positions and Feeds for Encapsulation: The mold design incorporates edging positions and feeds to encapsulate the edges and ports of the transparent window. This design ensures a secure and uniform integration of the transparent window during the over molding process, contributing to the overall structural integrity of the final respiratory mask.

[0082] At Step 712, Trimming Process Precision: A trimming process is developed to trim the formed material to the correct shape, including filter ports and periphery. In an example trimming process computer numerical control (CNC) machining is used which may convert a computer-aided design (CAD) drawing to computer code for the CNC machine to then execute. This trimming process achieves the final mask shape, maintaining consistency across the production line.

[0083] At Step 714, Sheet Conversion via injection molding or Vacuum Forming: The sheet conversion process begins with injection molding or vacuum forming, where the material isheated and shaped using injection molding or vacuum pressure. This step establishes the initial form of the anti fog sheet, preparing it for the subsequent stages of the manufacturing process..

[0084] At Step 716, Transfer to Injection Molding Tool: Following the sheet conversion, the shaped material is transferred to an injection molding tool. This transition is managed to ensure the reproduction of the formed shape during the over molding process by holding the mask in place, setting the stage for the final integration of the transparent window. The mask may be made by injection forming, with a designated section for the anti-fog window.

[0085] At Step 718, Over molding Process Execution: In the final stages, the over molding process is executed using the injection molding setup. The chosen material (which may be a PETG or PC treated with an anti-fog solution such as PU) is injected into the mold, effectively integrating the transparent window onto the respiratory mask. Curing and cooling processes follow, ensuring a strong bond between the transparent window and the mask surface, resulting in a final product that shows visual communication and is structurally sound. The anti-fog window can be overmolded to the body of the mask in the designated section.

[0086] In the above method, the body of the mask and the filter ports may be all molded in the same step, followed by the transparent window being over-molded.ADVANTAGES OF THE PRESENT DISCLOSURE

[0087] Communication: The integration of a transparent window allows for facial expressions and lip-reading, which aids communication . This can be useful in environments such as healthcare settings. The masks described herein can provide general health and safety in working environments where wearing Respiratory Protective Equipment (RPE) is important, essential or mandated.

[0088] Visibility: The transparent plastic window ensures visibility, addressing the limitations of opaque and translucent masks, or transparent masks with no anti-fog coating. It should be noted that powered respirators generally don’t use anti-fog coatings as air is being pushed into the mask, which to some extent prevents offing, but this effect does not always work well. This feature is valuable for professions where visual cues are essential.

[0089] Versatility Across Mask Types: The over molding process may need to be adapted depending on the mask type. The over-molding process can be used for various respiratory mask types, including Pl, P2, P3, transparent alternatives to surgical masks, anaesthetic masks, and bothpowered respirators and non-powered respirators. Non-powered respirators may refer to negative pressure respirators. The adaptation required in the over molding process resulting from the mask materials varying and requiring a different temperature or molding speed for the over-molding process. This makes the modified mask applicable across diverse industries and use cases.

[0090] Maintained Structural Integrity: The design and manufacturing process ensure that the over molding of the transparent window onto the mask does not compromise the structural integrity of the respiratory mask. The final product retains its protective functionality.

[0091] Anti-Fog Properties: Using anti fog materials which may comprise Silicone or thermoplastic materials including PET, PETG, BOPET, RPET, APET, PC, TPE, or TPU pretreated with anti-fog solution that is long-lasting so that the mask may experience the anti-fog properties for the duration of the mask’s life span, ensures visibility even in conditions prone to fogging, This feature may be beneficial for sustained use of the mask.

[0092] The invention can be applied to various fields. In the Healthcare industry, healthcare professionals, including doctors and nurses, can benefit from visual communication, including facial expressions and lip reading, while maintaining a high level of protection. In educational institutions, the transparent window over molding addresses the challenges posed by traditional masks in visual communication. It allows educators to convey information through visual communication while ensuring safety. In industrial and manufacturing settings, where workers rely on communication for safety and coordination, the transparent window over molding may be suitable. It enables visibility and communication on the factory floor. Professionals in public-facing roles, such as customer service representatives, retail workers, and public safety officers, may benefit from the communication enabled by the transparent window over molding. Individuals in the transportation sector, including pilots, flight attendants, and public transport operators, may benefit from the communication facilitated by the transparent window over molding, especially in situations regarding verbal or visual communication, including facial expressions and lip reading. The invention can be used in the armed forces, such as navy officers working on nuclear submarines need to be able to communicate effectively. The invention can be used in the fire and rescue services, where there is a need for clear and safe communication. The invention is also applicable to everyday scenarios where individuals seek to communicate visually while wearing masks. This includes social interactions, gatherings, and events where visual communication is present.Y1

[0093] Further, the invention may find use in gas masks or any type of mask used for respiration protection.

[0094] Any one of the presently described embodiments may be advantageously combined with any other one.

[0095] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value with a range is incorporated into the specification as if it were individually recited herein. All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention

Claims

CLAIMS1 / WE CLAIM1. A face mask comprising: a window section comprising a first material, wherein the first material is transparent and treated with an anti-fog solution, and wherein the window section is configured to overlap with a mouth of a wearer of the face mask when the face mask is worn such that the mouth of the wearer is visible when the face mask is worn; a second section comprising a second material that is more flexible than the first material, wherein the second section surrounds a perimeter of the window section and wherein the second section comprises a lip section for making contact with the wearer when the face mask is worn.

2. The face mask according to claim 1, wherein the second material is not treated with the anti-fog solution.

3. The face mask according to claim 1 or claim 2, wherein the second material is translucent.

4. The face mask according to any preceding claim, wherein the first material comprises polyethylene terephthalate glycol, PETG.

5. The face mask according to any of claims 1 to 3, wherein the first material comprises polycarbonate, PC.

6. The face mask according to any preceding claim, wherein the anti-fog solution comprises polyurethane.

7. The face mask according to any preceding claim, wherein the second material comprises thermoplastic elastomer, TPE.

8. The face mask according to any preceding claim, wherein the second section provide a base structure of the face mask, excluding a cavity in which the window section is positioned.

9. The face mask according to any preceding claim, wherein the window section is overmolded onto the second section.

10. The face mask according to any preceding claim, wherein the face mask comprises a face mask respirator.

11. The face mask according to any of claims 1 to 9, wherein the face mask comprises a filter port in which re-useable filter pads can be placed.

12. A method of manufacturing a face mask comprising: injection molding or vacuum forming a window section of the face mask, wherein the window section comprises a first material that is transparent and treated with an anti-fog solution; injection molding or vacuum forming a second section of the face mask, wherein the second section comprises a second material that is more flexible than the first material; integrating the window section of the face mask onto the second section of the face mask such that the second section surrounds a perimeter of the window section, wherein the windowsection is configured to overlap with a mouth of a wearer of the face mask when the face mask is worn such that the mouth of the wearer is visible when the face mask is worn and wherein the second section surrounds a perimeter of the window section .

13. The method of claim 12, wherein the integrating comprises an over-molding process.

14. The method of claim 12 or claim 13, wherein the second section comprises a base structure of the mask with a cavity for integrating the first window section.

15. The method of claim 14, wherein the window section matches contours of the cavity.

16. The method of any of claims 12 to 15, wherein the method comprises trimming at least one of: the window section; and the second section.

17. The method of any of claims 12 to 16, wherein the second material is not treated with the anti-fog solution.

18. The method of any of claims 12 to 17, wherein the second material is translucent.

19. The method of any of claims 12 to 18, wherein the first material comprises polyethylene terephthalate glycol, PETG.

20. The method of any of claims 12 to 18, wherein the first material comprises polycarbonate, PC.

21. The method of any of claims 12 to 20, wherein the anti-fog solution comprises polyurethane.

22. The method of any of claims 12 to 21, wherein the second material comprises thermoplastic elastomer, TPE.

23. The method of any of claims 12 to 22, wherein the second section provide a base structure of the face mask, excluding a cavity in which the window section is positioned.

24. The method of any of claims 12 to 23, wherein the face mask comprises a face mask respirator.

25. The method of any of claims 12 to 24, wherein the face mask comprises a filter port in which re-useable filter pads can be placed.

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