Method for manufacturing a full-face mask for an air-purifying respirator and such a mask

Abstract

A method of manufacturing a full-face mask (1) for an APR (air-purifying respirator) or a PAPR (powered air-purifying respirator), the method comprising: providing a sheet (100) of a first material of a transparent polymer; cutting out visors (10, 110) from the sheet; forming the visors (10, 110) into a three-dimensional shape; and forming a frame (20, 120) around the visors (10, 110) by injection molding a second material onto peripheral portions (11, 111) of the visors in a first mold (103). A full-face mask for an APR or a PAPR is also disclosed.

Description

Technical Field

[0001] The present disclosure generally relates to APR (Air-Purifying Respirator) and PAPR (Powered Air-Purifying Respirator), and more specifically to a method for manufacturing a full-face mask for APR or PAPR. Also disclosed is a full-face mask for APR or PAPR.

Background Art

[0002] An air-purifying respirator is an air filtration device that protects against inhalation of both large and small particles by removing contaminants by filtration or absorption. They may be passive APRs or powered PAPRs. PAPRs have a significant advantage over APRs as they require only a simple fit test and do not increase respiration. Also, PAPRs provide a positive pressure inside the face mask, reducing the risk of leakage into the mask caused by growth such as beards or wrinkles.

[0003] An important aspect when using APRs and PAPRs is to provide a widely undistorted field of view and be lightweight and comfortable to wear. APRs and PAPRs can be used in many different environments for many different purposes and in many different applications. Such different usage conditions require the full-face mask to exhibit different characteristics. For example, the material forming the full-face mask should exhibit different characteristics when the APR / PAPR is intended for use at different ambient temperatures, such as in firefighting activities, indoor at room temperature, cold or extremely cold outdoors. In some applications, the material needs to withstand the surrounding aggressive atmosphere. Further, in some applications, the visor of the full-face mask may need to exhibit certain material-dependent characteristics such as shielding, anti-reflective, or scratch protection properties. For these reasons, there is a need to provide a method for manufacturing a full-face mask that allows the material used to form the full-face mask to be freely selected.

[0004] Patent Document 1 discloses a full-face mask for PAPR. The full-face mask has a single-curved surface viewing portion and is integrally manufactured from transparent plastic in a one-step vacuum forming process. The face seal portion may be manufactured as a separate component by vacuum forming and cutting a central opening adapted to the full-face mask. The face seal portion is then adhered to the full-face mask. Alternatively, the face seal portion may be formed integrally with the full-face mask in a one-step vacuum forming process.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] An object of the present disclosure is to provide an improved method for manufacturing a full-face mask for APR or PAPR.

[0007] Another object is to provide a method that allows a high degree of freedom in selecting the materials included in the full-face mask.

[0008] A further object is to provide a method by which the full-face mask can be manufactured at low cost.

[0009] Yet another object is to provide such a method that enables high-speed manufacturing.

[0010] Yet another object is to provide an improved full-face mask for APR or PAPR.

[0011] Generally, all terms used in the claims should be construed in accordance with their ordinary meaning in the technical field, unless explicitly defined otherwise in this specification. All references to elements, devices, components, means, steps, etc. should be construed as referring to at least one of the elements, devices, components, means, steps, etc., unless explicitly stated otherwise. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless explicitly recited.

[0012] According to a first aspect, the present disclosure provides a method of manufacturing a full-face mask for APR or PAPR as defined in appended claim 1. This manufacturing method includes the following steps, namely, providing a sheet of a first material of a transparent polymer; cutting out a visor from the sheet; forming the visor into a three-dimensional shape; forming a frame around the visor by injection molding a second material around the visor within a first mold.

[0013] Thus, the method provides that a full-face mask comprising a visor and a frame surrounding the visor can be easily manufactured quickly and at low cost, while enabling the visor and the frame to be formed from a wide variety of different materials using the same production line.

[0014] Before being inserted into the first mold for injection molding the frame around the perimeter of the visor, the visor may be formed into a three-dimensional shape by a separate bending or thermoforming operation.

[0015] However, in a preferred embodiment, the step of forming the bezel into a three-dimensional shape is performed in the first mold by applying heat to the bezel and closing the first mold. Thus, in such an embodiment, a planar bezel cut out from the first sheet material is placed in the first mold and then formed into a three-dimensional shape inside the mold before the frame is injection molded onto the bezel. By this means, another operation of forming the three-dimensional bezel is eliminated.

[0016] The method can further include the step of forming a face-sealing rim at the peripheral portion of the frame by injection molding a third material at the peripheral portion of the frame.

[0017] The step of forming the face-sealing rim may be performed in a second mold different from the first mold.

[0018] The steps of forming the frame and the face-sealing rim may be performed on one and the same injection molding machine by 2K injection molding or multi-material molding.

[0019] The step of forming a frame around the bezel can include fusing or adhering a second raw material to a first raw material. Such fusing or adhering of the frame to the bezel can preferably be carried out when the bezel and the frame comprise the same or chemically fusible or adherable materials.

[0020] Alternatively, or in combination, the step of forming a frame around the bezel may include forming a mechanical engagement between the frame and the bezel. Such a mechanical engagement between the frame and the bezel can be carried out when the frame and the bezel comprise non-fusible or non-adherable materials and / or when a particularly strong mutual fixation of the two components is desired.

[0021] The step of forming a face-sealing rim around the frame can include fusing or adhering a third material to a second material.

[0022] Alternatively, or in combination, the step of forming a face-sealing rim around the frame may include forming a mechanical engagement between the face-sealing rim and the frame. Such a mechanical engagement between the face-sealing rim and the frame can be implemented when the face-sealing rim and the frame include non-fusible or non-adhesive materials, and / or when particularly strong mutual fixation of the two components is desired.

[0023] The first material can include PETG or PC.

[0024] The second material can be selected from the group of PETG, PC, PA, PP, ABS, and TPE.

[0025] Both the first and second materials may include PETG or PC. By forming the visor and the frame of the same material, mutual fixation of the two components by fusion or adhesion is facilitated.

[0026] The third material may be selected from the group of TPE, silicone resin, and rubber.

[0027] This method can further include the step of coating at least one side of the visor with a layer of a fourth material. The fourth material may be, for example, a material exhibiting shielding, anti-reflective, and / or scratch protection properties.

[0028] The step of coating the visor with a layer of the fourth material may preferably be performed before the step of forming a frame around the visor, such as before the step of forming the visor into a three-dimensional shape.

[0029] According to a second aspect, the present disclosure provides a full-face mask for an APR (air-purifying respirator) or a PAPR (powered air-purifying respirator) as defined in independent claim 15. The full-face mask includes a visor having a cutout of a first sheet material of a transparent polymer formed in a three-dimensional shape, and a frame formed of a second material injection-molded around the periphery of the visor. The full-face mask may further include a face seal rim injection-molded around the periphery of the frame.

[0030] Further objects and advantages of the method and the full-face mask will be apparent from the following description of the embodiments and the appended claims.

Brief Description of the Drawings

[0031] Here, with reference to the accompanying drawings, the aspects and embodiments will be described by way of example.

Fig. 1a

Fig. 1b

Figs. 2a - 2c

Best Mode for Carrying Out the Invention

[0032] Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which specific embodiments of the invention are shown.

[0033] However, these aspects may be embodied in many different forms and should not be construed as limiting, but rather these embodiments are provided by way of example so that this disclosure will be thorough and complete and will fully convey the scope of the technology of all aspects of the invention to those skilled in the art. Like reference numerals refer to like components throughout the description.

[0034] Figures 1a and 1b show an embodiment of a full-face mask 1 for APR or PAPR. The full-face mask 1 is manufactured by a manufacturing method as follows. The full-face mask 1 includes a visor 10, a frame 20, and a face-sealing rim 30. In use, the APR or PAPR includes additional components not shown in the figures. Such components may include at least one filter unit, a blower or fan for providing positive pressure within the mask, a power source, a valve element, and a harness for holding the mask so that the mask covers the wearer's face. Such components and their functions are well known in the art and will not be further described herein.

[0035] The visor 10 is formed from a sheet of a transparent polymeric material. Examples of materials for forming the visor are PETG (polyethylene terephthalate glycol) and PC (polycarbonate). However, other sheets formed of a transparent polymeric material having eye clarity and being bendable or thermoformable into a three-dimensional shape may be used to form the visor. The visor has a three-dimensional shape with a peripheral portion 11.

[0036] The frame 20 is formed from an injection-moldable polymeric material. Examples of such materials are PETG, PA, PC (polycarbonate), PP (polypropylene), ABS (acrylonitrile butadiene styrene), and TPE (thermoplastic elastomer). The frame 20 has a three-dimensional shape with a peripheral portion 21 and a central through-opening 22 surrounded by an edge portion 23. The visor 10 is received within the central through-opening 22, and the peripheral portion 11 of the visor is sealed and fixed along the edge portion 23 of the frame.

[0037] When the visor 10 and the frame 20 include materials that are mutually fusible and / or bondable, for example, when both the visor 10 and the frame 20 include PETG or PC, the mutual fixation of the two components can be achieved by material fusion and / or adhesion. In other cases, or in addition, the visor 10 and the frame may be mutually fixed by mechanical engagement means. Such engagement means may include, for example, a U-shaped groove (not shown) that extends along the inner edge 23 of the frame 20 and snugly receives the peripheral portion 11 of the visor 10. Such engagement means can alternatively or in combination include cooperating recesses and protrusions arranged along the peripheral portion 11 of the visor 10 and the inner edge 23 of the frame 20.

[0038] When the mutual fixation between the visor 10 and the frame 20 is realized by fusion, adhesion, and mechanical engagement means, in both cases, the mutual fixation between the two components is achieved during the first injection molding operation when the frame 20 is injection molded onto the peripheral portion 11 of the visor 10.

[0039] The frame 20 also includes a second opening 24 for arranging the valve element and a filter unit (not shown here in detail). Such additional components are usually attached to the full-face mask 1 after the completion of the mask 1 including the visor 10, the frame 20, and the face-sealing rim 30.

[0040] The face-sealing rim 30 is arranged to make a sealing contact with the wearer's face, thereby sealing the interior of the mask 1 from the surrounding air during use. The face-sealing rim 30 is formed from an injection-moldable flexible polymer material. Examples of such materials suitable for the face-sealing rim are TPE, silicone, and rubber. The face-sealing rim 30 has a three-dimensional shape having a peripheral portion 31 arranged to make a sealing contact with the wearer's face and a central through-opening 32 surrounded by an edge 33. The frame 20 is received within the central through-opening 32, and the peripheral portion 21 of the frame is sealingly fixed along the edge 33 of the face-sealing rim 30.

[0041] If the frame 20 and the face seal rim 30 include materials that are mutually fusible and / or bondable, for example, if both the frame 20 and the face seal rim 30 include TPE, the mutual fixation of the two components can be achieved by material fusion and / or bonding. In other cases, or additionally, the frame 20 and the face seal rim 30 may be fixed to each other by mechanical engagement means. Such engagement means may, for example, comprise a U-shaped groove (not shown) that extends along the inner edge 33 of the face seal rim and snugly receives the peripheral portion 21 of the frame 20. Such engagement means may alternatively, or in combination, comprise cooperating recesses and protrusions arranged along the peripheral portion 21 of the frame 20 and the inner edge 33 of the face seal rim.

[0042] The face seal rim 30 also comprises a number of outwardly projecting flexible tabs 34 arranged for fixing a harness (not shown) for holding the full-face mask 1 to the wearer's head.

[0043] Figures 2a - 2c schematically show embodiments of a method of manufacturing a full-face mask for APR or PAPR.

[0044] Figure 2a shows a first step, in which a sheet 100 of a first material of a transparent polymer is provided on a roll 101 and fed to a punching machine 102 for punching out the visor 110 from the sheet 100. In some embodiments, a rolling machine (not shown) may be arranged between the material roll 101 and the punching machine 102 for relaxing the material and enhancing the planarity of the sheet 100. After being punched out from the sheet 100, the visor has an essentially planar two-dimensional shape with a peripheral portion 111.

[0045] Figure 2b shows the second and third steps of the method. The planar visor 110 is placed within a mold 103 of a first injection molding machine. The mold 103 comprises two mold halves 103a, 103b and a passage 103c for providing a material injectable within the mold cavity.

[0046] After placing the planar visor 110 within the mold 103, the mold is closed. By closing the mold 103, the planar visor is reshaped from a two-dimensional to a three-dimensional shape corresponding to the internal shape of the mold 103. During this reshaping of the visor, heat may be applied to the mold 103 and thereby to the visor 110 so that the visor is reshaped by thermoforming.

[0047] In the next step, a second material is injected into the interior of the mold 103 through the passage 103c. The internal shape of the mold is arranged such that the injected material contacts the peripheral portion 111 of the visor 110 and forms a three-dimensional frame 120 having a peripheral portion 121 around the visor 110.

[0048] FIG. 2c shows a further step of the method. The three-dimensional aggregate visor 110 and the frame 120 are placed within the mold 104 of a second injection molding machine. The mold 104 includes two mold halves 104a, 104b and a passage 104c for providing an injectable material within the mold cavity.

[0049] After placing the aggregate visor 110 and the frame 120 within the mold 104, the mold is closed. Then, a third material is injected into the interior of the mold 104 through the passage 104c. The internal shape of the mold is arranged such that the injected material contacts the peripheral portion 121 of the frame 120 and forms a three-dimensional face seal rim 130 having a peripheral portion 131 around the aggregate visor 110 and the frame 120.

[0050] In another embodiment of the method not shown, the planar visor 110 is reshaped into a three-dimensional shape by a separate bending operation or thermoforming operation after the punching operation shown in FIG. 2a and before being placed within the mold 103 for injection molding the frame 120 to the peripheral portion 111 of the visor 110.

[0051] In another non - illustrated embodiment, both injection molding operations are performed on one and the same injection molding machine. This can be achieved by so - called 2K injection molding operations or multi - material molding (MMM) operations. In such an operation, one of the mold halves is rotatable and has two mold cavities. The planar visor may be placed in the first cavity, after which the mold is closed to reform the visor into a three - dimensional shape. Thereafter, a second material is injected to form a frame around the visor. When the frame has cured, the mold is opened, the rotatable half is rotated, and the two mold halves are closed to define a mold cavity for forming a face - sealing rim around the frame. Thereafter, a third material is injected into the mold cavity, whereby the face - sealing rim is formed around the periphery of the frame.

[0052] In a further non - illustrated embodiment, the planar visor is reformed into a three - dimensional shape in a separate bending or thermo - forming operation and thereafter the frame and the face - sealing rim are successively formed by a 2K injection operation or an MMM operation.

[0053] Aspects of the present disclosure have mainly been described above with reference to several embodiments and examples thereof. However, as will be readily understood by those skilled in the art, other embodiments other than those disclosed above are equally possible within the scope of the invention as defined by the appended claims.

Claims

1. A method for manufacturing a full-face mask (1) for an APR (air-purifying respirator) or a PAPR (powered air-purifying respirator), comprising: preparing a sheet (100) of a first material of a transparent polymer; cutting out visors (10, 110) from the sheet (100); forming the visors (10, 110) into a three-dimensional shape; and forming a frame (20, 120) around the visors (10, 110) by injection molding a second material around a peripheral portion (11, 111) of the visors (10, 110) within a first mold (103).

2. The method according to claim 1, wherein the step of forming the visors (10, 110) is performed in the first mold (103) by applying heat to the visors (10, 110) and closing the first mold (103).

3. The method according to claim 1 or 2, further comprising forming a face-sealing rim (30, 130) around the frame (20, 120) by injection molding a third material around a peripheral portion (21, 121) of the frame (20, 120).

4. The method according to claim 3, wherein the step of forming the face-sealing rim (30, 130) is performed in a second mold (104) different from the first mold (103).

5. The method according to claim 3 or 4, wherein the steps of forming the frame and the face-sealing rim are performed in the same injection molding machine by 2K injection molding or multi-material molding.

6. The method according to any one of claims 1 to 5, wherein the step of forming a frame (20, 120) around the visor (10, 110) includes fusing or bonding the second material to the first material.

7. The method according to any one of claims 1 to 6, wherein the step of forming a frame (20, 120) around the visor (10, 110) includes forming a mechanical engagement portion between the frame (20, 120) and the visor (10, 110).

8. The method according to any one of claims 3 to 7, wherein the step of forming a face-sealing rim (30, 130) around the frame (20, 120) includes fusing or bonding the third material to the second material.

9. The step of forming a face-sealing rim (30, 130) around the frame (20, 120) includes the step of forming a mechanical engagement portion between the face-sealing rim (30, 120) and the frame (20, 120), the manufacturing method according to any one of claims 3-8.

10. The manufacturing method according to any one of claims 1-9, wherein the first material includes PETG or PC.

11. The manufacturing method according to any one of claims 1-10, wherein the second material is selected from the group consisting of PETG, PC, PA, PP, ABS, and TPE.

12. The manufacturing method according to any one of claims 1-11, wherein both the first and second materials include the same polymer material, preferably PETG or PC.

13. The manufacturing method according to any one of claims 1-12, wherein the third material is selected from the group consisting of TPE, silicone resin, and rubber.

14. The manufacturing method according to any one of claims 1-13, including the step of coating at least one side of the visor with a layer of a fourth material.

15. A full-face mask (1) for an APR (air-purifying respirator) or a PAPR (powered air-purifying respirator), a visor (10, 110) including a cut-out piece of a sheet (100) of a first material of a transparent polymer formed in a three-dimensional shape, and a frame (20, 120) formed of a second material injection-molded around a peripheral portion (11, 111) of the visor (10, 110).

16. The full-face mask according to claim 16, further comprising a face-sealing rim (30, 130) injection-molded around a peripheral portion (21, 121) of the frame (20, 120).

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