Polypropylene and polytetrafluoroethylene combination face mask

Abstract

A face mask is provided that includes a first outer polypropylene layer, a second outer polypropylene layer, an inner layer of a polytetrafluoroethylene and polypropylene composite disposed between the first and second outer polypropylene layers, and at least one strap secured to an outer surface of one of the outer layers, and that, in addition to the above components, also includes a transparent window.

Description

Technical Field

[0001] The present invention relates to multilayer masks of polypropylene (PP) and polytetrafluoroethylene (PTFE). One embodiment also relates to a multilayer mask of polypropylene (PP) and polytetrafluoroethylene (PTFE) having a transparent window therein.

Background Art

[0002] SARS-CoV-2 or COVID-19 is a highly infectious virus that spreads rapidly and was first detected in China in December 2019. Since its discovery, it has spread around the world, infecting 266 million people. Currently, as of December 1, 2021, COVID-19 has caused 5.2 million deaths worldwide. To avoid complete lockdowns and prevent the spread of the virus, various countries have enacted and / or reenacted mask mandates that require various levels of compliance in public places, such as wearing masks in all indoor facilities and when going out in public in more populated areas.

[0003] As of December 3, 2021, COVID-19 has mutated into two new strains: the Delta variant, which was dominant in 2021, and the Omicron variant, which was newly discovered in late November 2021. The Delta variant has been shown to have increased infectivity compared to the original strain of COVID-19, and preliminary information predicts that the Omicron variant also has increased infectivity.

[0004] In this technical field, personal protective equipment (PPE) has long included face coverings. PPE face masks have traditionally been worn in healthcare facilities to avoid the transmission of disease to high-risk patients. PPE face masks are considered best practice for surgical procedures to maintain a sterile environment while reducing the risk of infection. Face masks first became widely used in East Asian countries and are now common worldwide in light of COVID-19. Given the emergence of new mutations in COVID-19 and their increased infectivity, PPE has become a primary method for reducing infection.

[0005] Meltblown polypropylene is used as the middle layer in many certified medical masks and in the manufacture of respirators such as N95 masks. These masks, which are woven with multiple layers of polypropylene, become electrostatically charged and are very effective at trapping airborne particles. However, polypropylene masks are typically only effective for about four hours because the moisture accumulated from the user's breathing negates the electrostatic properties of polypropylene.

[0006] Conventional surgical face masks include versions with a transparent section that sits over the user's mouth. These face masks are designed to be secured to the user via a head strap fixed to the outer surface of the face mask and may or may not include a filter section containing antimicrobial material. However, the effectiveness of these face masks, including those with a transparent window, may not meet certain standards required of healthcare providers. Such standards include those of Health Canada and ASTM International, formerly known as the American Society for Testing and Materials. [Overview of the initiative] [Problems that the invention aims to solve]

[0007] Thus, there has been a long-standing need for a face mask that complies with ASTM international standards and Health Canada standards, maintaining breathability and dryness even after prolonged use, while possessing excellent resistance to blood and bodily fluids. Furthermore, there has also been a long-standing need for a face mask that possesses the above characteristics, complies with ASTM international standards and Health Canada standards, and is designed to have a transparent section that allows the user's mouth to be seen. [Means for solving the problem]

[0008] The present invention generally comprises a first polypropylene outer layer, a second polypropylene outer layer, an inner layer of a polytetrafluoroethylene and polypropylene bond disposed between the first and second polypropylene outer layers, and at least one strap fixed to the outer surface of one of the outer layers.

[0009] The present invention also generally comprises a first polypropylene outer layer having an opening, a second polypropylene outer layer having an opening, an inner layer of polytetrafluoroethylene and polypropylene composite having an opening and disposed between the first and second polypropylene outer layers, a transparent window disposed so as to overlap the openings of the outer and inner layers and fixed to the outer surface of the first polypropylene outer layer, and at least one strap fixed to the outer surface of one of the outer layers.

[0010] A general objective of the present invention is to provide a face mask that filters moisture when it accumulates in the mask due to the user's breathing over a long period of time, such as four hours or more.

[0011] A further object of the present invention is to provide a face mask that includes a transparent portion so that the user's mouth is visible, which enhances audibility and is aesthetically more appealing in environments where the user frequently communicates.

[0012] Another object of the present invention is to provide a face mask having a specific folding or pleating shape that increases the distance from the user's mouth to the inner surface of the face mask and the window within it, thereby improving audibility and general comfort.

[0013] A further object of the present invention is to provide a face mask that conforms to ASTM F2100-19 Level 2 and 3 compliance levels.

[0014] A further objective of the present invention is to provide a face mask that conforms to the standards of Health Canada.

[0015] The above and other objects, features, and advantages of the present invention will become readily apparent by considering the following detailed description of the invention in view of the drawings and the appended claims. Various embodiments are disclosed only as examples with reference to the appended schematic drawings, where corresponding reference numerals indicate corresponding parts. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a left front perspective view showing the usage state of the first embodiment of the present invention. [Figure 2] Figure 2 is a right front perspective view showing the usage state of the second embodiment of the present invention. [Figure 3A] Figure 3A is a perspective view of the first embodiment of the present invention in a non-pleated configuration. [Figure 3B] Figure 3B is a perspective view of the first embodiment of the present invention in a pleated configuration. [Figure 4A] Figure 4A is a perspective view of a second embodiment of the present invention in a non-pleated configuration. [Figure 4B] Figure 4B is a perspective view of a second embodiment of the present invention in a pleated configuration, and also shows an enlarged view of the pleat arrangement. [Figure 5A] Figure 5A is a cross-sectional view of the first embodiment of the present invention in a non-pleated configuration, cut along the line 5A-5A shown in Figure 3A. [Figure 5B]FIG. 5B is a cross-sectional view of a second embodiment of the present invention in a non-pleated configuration, taken along line 5B-5B shown in FIG. 4A. [Figure 6] FIG. 6 is an exploded view of a first embodiment of the present invention. [Figure 7] FIG. 7 is an exploded view of a second embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] First, it should be understood that like reference numerals in different drawings identify the same or functionally similar structural elements. It should be understood that the claims are not limited to the disclosed embodiments.

[0018] Furthermore, it is understood that the present disclosure is not limited to the specific methodologies, materials, and modifications described, and that such variations are possible. It is also understood that the terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the claims.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should be understood that methods, apparatus, or materials similar or equivalent to those described herein may be used in the implementation or testing of exemplary embodiments.

[0020] The term "substantially" is synonymous with terms such as "nearly", "very close", "about", "approximately", "perimeter", "boundary", "near", "essentially", "vicinity", "adjacent", etc., and such terms may be used interchangeably as they appear in this specification and the claims. The term "proximate" is synonymous with terms such as "vicinity", "near", "adjacent", "next", "adjacent to", etc., and such terms may be used interchangeably as they appear in the specification and the claims.

[0021] It should also be understood that directional terms, such as “up,” “up,” “down,” “down,” “right,” “left,” and similar variations thereof, are also related to the corresponding figures described herein as they are illustrated. For example, “component X is positioned to the right of component Y” means that “component X” is positioned to the right of “component Y” with respect to the relevant drawing.

[0022] Hereafter, polypropylene will be referred to as "PP" in this specification. Similarly, polytetrafluoroethylene will be referred to as "PTFE" hereafter.

[0023] Next, the drawings will be described. Figure 1 is a left front perspective view showing the use of a first embodiment of the present invention. It illustrates a user 500 wearing a PP and PTFE combination face mask 100 (hereinafter referred to as "mask 100"). The mask 100 is secured to the user's face via ear loops 501 and 502 (502 is shown in Figure 2 as seen from mask 200). In the embodiment shown in Figure 1, the mask 100 is secured around the user's ears via ear loops 501 and 502, but it should be understood that alternatively, the ear loops 501 and 502 may be configured to be positioned around the back of the user's neck and head. Although the exemplary figures of the present invention depict a pair of ear loops, it should be understood that a third strap may be included to provide a better seal around the user's nose and mouth. The ear loops 501 are secured to the mask 100 via ultrasonic welded sections 441 and 442. The first outer layer 10 of the mask 100 faces away from the user 500's face. The mask 100 consists of three layers welded together by ultrasonic welding. In a preferred embodiment, the mask 100 includes four ultrasonic welded sections 401, 402, 403 (shown in Figure 2), and 404 that define the periphery of the mask. These welded sections function to provide the best bodily fluid resistance, bacterial filtration efficiency, particulate filtration efficiency, and breathability (when the nasal and oral passages are covered by the mask 100). The specific standard requirements for each of these categories, along with the effects that the mask 100 provides, will be discussed later.

[0024] It should be understood that the mask 200 includes all the components of the mask 100 and is rotated in Figure 2 to show the right side of the user 500. Figure 2 is a left front perspective view showing the second embodiment of the present invention in use. The PTFE and PP combination face mask 200 with a transparent window (hereinafter referred to as "mask 200") also consists of a window 60 and openings provided in each of the three layers of the mask 200, which will be described later with reference to Figure 5B. The window 60 is fixed to the first outer layer 10 of the mask 200 via a window ultrasonic welding section 48 surrounding the outer periphery of the window 60. The specific standard requirements of each of these categories will be described later, along with the effects that the mask 200 provides. Figure 2 also shows ultrasonic welding sections 403 and 404 positioned to fix the ear loops 502 to the first outer layer 10 of the mask 200. It should be understood that the ultrasonic welding sections 403, 404 and the ear loops 502 are also present on the mask 100, as shown in Figure 1.

[0025] The mask 200 allows the user 500's mouth to be seen through the window 60, facilitating verbal communication, i.e., enabling lip-reading. The window 60 is preferably made of an anti-fogging plastic material, and in a preferred embodiment, is made of polyethylene. This is useful in reducing the social intimidation that may be experienced in a child's classroom through the COVID-19 mask procedure where teachers and students can see each other's mouths, or in other situations such as occupational therapy or mental health settings. The window 60 can serve a security purpose by making it easier to identify the user 500 behind the mask 200, for example, in environments where the user 500 may be required to present identification for entry and temporary removal of the mask may be prohibited, such as in a hazardous chemical or biological laboratory, or in cases where removing the mask is unnecessarily dangerous, such as for immunocompromised individuals.

[0026] Please refer to Figures 3A and 3B for the following explanation. Figure 3A is a rear perspective view of the non-pleated mask 100, and Figure 3B is a rear perspective view of the pleated mask 100. Figures 3A and 3B show the inside of the mask 100, i.e., the face surface 21 of the second outer layer 20. In a preferred embodiment, the mask 100 is positioned so that the second outer layer 20 is fitted close to the user's face so that various body structures, such as the nose, chin, and cheeks, can come into contact with the face surface 21 of the second outer layer 20. Upper ultrasonic welding sections 401 and sleeve ultrasonic welding sections 42 are located near the top of the mask 100, and these together secure all three layers of the mask 100 (shown in Figures 5A and 5B). Lower ultrasonic welding section 404 is located near the bottom of the mask 100. The upper ultrasonic welding section 401, the lower ultrasonic welding section 404, and the sleeve ultrasonic welding section 42 secure all three layers of the mask 100 together at the top and bottom of the mask 100 (shown in detail in Figure 5A). The ear loops 501 and 502 are positioned to secure the mask 100 to the user's face, as illustrated in Figure 1. The ultrasonic welding section 401 and the sleeve ultrasonic welding section 42 hold the nose piece 70 in place (see also Figure 5A). The nose piece 70 is made of a deformable material, such as thin metal or plastic-coated metal.

[0027] To completely secure all three layers of the mask 100, a first ultrasonic welding section 402 and a second ultrasonic welding section 403 are provided on the sides of the mask 100. The first ultrasonic welding section 402 and the second ultrasonic welding section 403 also have the function of pleating the mask 100 by forming pleats P1 to P6. Pleats P1 to P6 are all folds on fold lines L1 to L6. Fold lines L1, L3, and L5 form pleats P1, P3, and P5 respectively, and all are upward folds, meaning that the mask 100 folds upward (the welding section 404 folds toward the welding section 42) and enters the face surface 21. Fold lines L2, L4, and L6 form pleats P2, P4, and P6, respectively, all of which are downward folds (the welded portion 404 is folded away from the welded portion 42), meaning that the mask 100 folds downward and away from the face surface 21. Pleats P1 to P6 form pinch points at their respective ends via the first ultrasonic welded portion 402 and the second ultrasonic welded portion 403. When the mask 100 is unfolded and worn, as shown in Figure 1, the pleats P1 to P6 unfold at a substantially central position between the first ultrasonic welded portion 402 and the second ultrasonic welded portion 403, while the ends of the pleats P1 to P6 remain folded at the first ultrasonic welded portion 402 and the second ultrasonic welded portion 403, so that the mask 100 spreads outwards and away from the user's face. This unfolding improves comfort and audibility. Furthermore, the distance from the pleats P1-P6 to the user's face and face surface 21 also serves to protect the individual from hygienic skin damage such as rashes or cosmetic blemishes that may result from the face surface 21 resting on the user's face.

[0028] Please refer to Figures 4A and 4B for the following description. Figure 4A is a perspective view of the mask 200 in a non-pleated configuration, and Figure 4B is a perspective view of the mask 200 in a pleated configuration. Figures 3A and 3B show the inside of the mask 200, i.e., the face surface 21 of the second outer layer 20. In a preferred embodiment, the mask 200 is positioned so that the second outer layer 20 is fitted close to the user's face so that various body structures, such as the nose, chin, and cheeks, can come into contact with the face surface 21 of the second outer layer. An upper ultrasonic welding section 401 and a sleeve ultrasonic welding section 42 are located near the top of the mask 200, and these together secure all three layers of the mask 200 (shown in Figure 5B). A lower ultrasonic welding section 404 is located near the bottom of the mask 200. The upper ultrasonic welding section 401, the lower ultrasonic welding section 404, and the sleeve ultrasonic welding section 42 secure all three layers of the mask 200 together at the top and bottom of the mask 200 (shown in detail in Figure 5B). Ear loops 501 and 502 are positioned to secure the mask 200 to the user's face, as shown in Figure 2. The ultrasonic welding section 401 and the sleeve ultrasonic welding section 42 hold the nose piece 70 in place (see also Figure 5B). The nose piece 70 is made of a deformable material, such as thin metal or plastic-coated metal. The mask 200 also includes a window 60, which in a preferred embodiment is positioned substantially horizontally in the center and vertically closer to the upper ultrasonic welding section 401 than to the lower ultrasonic welding section 404.

[0029] To completely secure all three layers of the mask 200, a first ultrasonic welding section 402 and a second ultrasonic welding section 403 are provided on the sides of the mask 200. The first ultrasonic welding section 402 and the second ultrasonic welding section 403 also have the function of pleating the mask 200 by forming pleats P1' to P6'. Pleats P1' to P6' are all folds on fold lines L1' to L6', respectively. Fold lines L1', L3', and L5' form pleats P1', P3', and P5', respectively. Fold line L1' is an upward fold, i.e., the mask 200 is folded upward and away from the face surface 21, and fold lines L3' and L5' are upward folds, i.e., the mask 200 is folded upward and inward from the face surface 21. Fold lines L2', L4', and L6' form pleats P2', P4', and P6', respectively. Fold line L2' is a downward fold, meaning the mask 200 folds downward and into the face surface 21. Fold lines L4' and L6' are downward folds, meaning the mask 200 folds downward and away from the face surface 21. Pleats P1' to P6' form pinch points at their respective ends via the first ultrasonic welding section 402 and the second ultrasonic welding section 403. When the mask 100 is unfolded and worn, as shown in Figure 2, the mask 200 spreads outwards and away from the user's face, with the pleats P1'~P6' unfolding at a substantially central position between the first ultrasonic welded portion 402 and the second ultrasonic welded portion 403, while the ends of the pleats P1'~P6' remain folded at the first ultrasonic welded portion 402 and the second ultrasonic welded portion 403. This unfolding improves comfort and audibility. Furthermore, the pleats P1'~P6' create distance between the window 60 and the user's face. This distance also serves to protect the individual from sanitary skin damage or cosmetic blemishes, such as rashes, that may occur on the makeup due to the face surface 21 and / or window 60 resting on the user's face.

[0030] Pleats P1' to P6' form four panels within the mask 200: a lower boundary panel 80, a connecting panel 82, an upper boundary panel 84, and a window panel 86. The lower boundary panel 80 is defined by the lower ultrasonic welding area 404 and the edge of the mask 200 adjacent to pleat P6', the connecting panel 82 is defined by pleats P5' and P4', the upper boundary panel 84 is defined by the welding area 42 and the edge of the mask 200 adjacent to pleat P1', and the window panel 86 is defined by pleats P2' and P3'. The window panel 60 is contained within the window panel 86 and is positioned on the panel furthest from the user's mouth or face. Pleats P1' to P6' form three different depths for panels 80 to 86. The lower boundary panel 80 is positioned at the proximal depth PD. The connecting panel 82 and the upper boundary panel 84 are positioned at the intermediate depth ID. The window panel 86 is positioned at a distal depth DD, which is the furthest point from the user's mouth and face, enhancing comfort even during prolonged use.

[0031] Figure 5A is a cross-sectional view of the mask 100 cut along the line 5A-5A shown in Figure 3A. Specifically, Figure 5A is an exaggerated cross-sectional view of the mask 100 to appropriately illustrate the stacking and positioning of the various components. The first outer layer 10 is the layer of the mask 100 facing away from the user's face, and the second outer layer 20 is the layer of the mask 100 facing closer to the user's face. The inner layer 30 is sandwiched between the first outer layer 10 and the second outer layer 20. The upper ultrasonic welding section 401 and the lower ultrasonic welding section 404 fix the layers 10, 20, and 30 together, specifically the lower end 16 of the first outer layer 10, the lower end 36 of the inner layer 30, and the lower end 26 of the second outer layer 20, respectively. In a preferred embodiment, the upper ultrasonic welding section 401 joins and fixes layers 10, 20, and 30 and their respective upper ends, i.e., the upper end 14 of the first outer layer 10, the upper end 34 of the inner layer 30, and the upper end 24 of the second outer layer 20, so that the nosepiece sleeve 72 is formed from the extra length between layers 10, 20, 30 and their upper ends 14, 24, 34 in the upper ultrasonic welding section 401. The nosepiece sleeve 72 forms a pocket 74 inside which a nosepiece 70 is positioned to hold the nosepiece 70. The pocket 74 is made tight to hold the nosepiece 70 by restricting its vertical movement within the pocket 74 via the sleeve ultrasonic welding section 42.

[0032] Referring to both Figures 5A and 5B, masks 100 and 200 are defined by three sections: a filtration section FS, a nosepiece section NS, and an upper section US. The filtration section FS is defined by the distance between the lower end 16 of the first outer layer 10, the lower end 36 of the inner layer 30, and the lower end 26 of the second outer layer 20, which constitute the lower end LE and the upper ultrasonic welding section 401. The nosepiece section NS is defined by the distance between the upper ultrasonic welding section 401 and the sleeve ultrasonic welding section 42. The upper section US is defined by the distance between the sleeve ultrasonic welding section 42 and the upper end UE.

[0033] Figure 5B is a cross-sectional view of the mask 200 cut along the line 5B-5B shown in Figure 4A. Specifically, Figure 5B is an exaggerated cross-sectional view of the mask 200 to appropriately illustrate the lamination and positioning of the various components. The mask 200 includes all of the aforementioned structural components of the mask 100 described with reference to Figure 5A, in addition to the specific structural components of the mask 200. Focusing on the additional components constituting the mask 200, the most notable is the window 60. In a preferred embodiment, the window 60 is fixed to the outer surface 11 of the first outer layer 10 of the mask 200 via a window ultrasonic welding section 48, as shown. The window ultrasonic welding section 48 is a continuous welding section positioned to surround the outer boundary of the window 60. The mask 200 also includes an opening 12 in the first outer layer 10, an opening 22 in the second outer layer 20, and an opening 32 in the inner layer 30. The window ultrasonic welding section 48 also fixes the outer boundaries of the openings 12, 22, and 32 so that there are no non-filter areas around the openings 12, 22, 32, and window 60. Window 60 is a non-filtering member, i.e., it has no voids whatsoever. The window ultrasonic welding section 48 allows the mask 200 to have the same effectiveness as the mask 100, even though the openings 12, 22, and 32 are present in the first outer layer 10, the second outer layer 20, and the inner layer 30, respectively.

[0034] Figure 6 is an exploded view of the mask 100. The mask 100 comprises four layers: a first outer layer 10 made of PP, a second outer layer 20 made of PP, and an inner layer 30 consisting of a laminated bond of a PP layer 30a and a PTFE layer 30b. The ear loops 501 and 502 are fixed to the outer surface of the first outer layer 10 by ultrasonic welding, as described above.

[0035] Figure 7 is an exploded view of the mask 200. The mask 200 comprises four layers: a first outer layer 10 made of PP, a second outer layer 20 made of PP, and an inner layer 30 consisting of a laminated combination of a PP layer 30a and a PTFE layer 30b. Each of the aforementioned layers has an opening. The first outer layer 10 has an opening 12, the second outer layer has an opening 22, the PP layer 30a of the inner layer 30 has an opening 32a, and the PTFE layer 30b has an opening 32b. The openings 12, 22, 32a, and 32b are collinear. The ear loops 501 and 502 are fixed to the outer surface of the first outer layer 10 by ultrasonic welding, as described above, and by any other feasible attachment method for textiles. The window 60 is fixed to the outer surface of the first outer layer 10 by ultrasonic welding, as described above. In a preferred embodiment, the window 60 is made of polyethylene. The window 60 may consist of 99.79% polyethylene and 0.21% of another suitable additive which may vary in production. In a preferred embodiment, the window 60 is Polyexpert® PEX-972-CLEAR-HS / anti-fog polyethylene and conforms to Food and Drug Regulation 21 CFR 177.1520. In a preferred embodiment, the window cover 62 is positioned to be removablely attached to the inner rims 12a, 32c, 32d, and 22a of the openings 12, 32a, 32b, and 22, respectively, for example by perforation. The window cover 62 is positioned to cover the surface of the window 60 facing the face surface 21 of the second outer layer 20. The window cover 62 keeps the window 60 clean and hygienic before use, or provides shade to the window 62 when transparency is not desired.

[0036] It should be understood that the PP layer 30a and PTFE layer 30b of the inner layer 30 are laminated together and can only be separated by forced removal, i.e., by breaking either mask 100 or mask 200, and are therefore shown as separate layers in Figures 6 and 7. Thus, the openings 32a and 32b of the PTFE layers 30a and 30b shown in Figure 7 are merely illustrative examples to illustrate the combination of material layers that make up the inner layer 30.

[0037] It is important to understand that polypropylene (PP) is a thermoplastic polymer used in a wide variety of applications. PP is produced by chain growth polymerization from its monomer, propylene. PP fabric is a nonwoven fabric and can be electrostatically charged to improve the filtration of airborne particles passing through the PP sheet. Thus, PP is an important raw material for manufacturing meltblown fabrics, and by extension, a raw material for manufacturing facial masks.

[0038] It should also be understood that polytetrafluoroethylene (PTFE) is a fluorocarbon solid, as it is a polymer compound consisting only of carbon and fluorine. PTFE is hydrophobic. Because fluorocarbons exhibit a relaxed London dispersion force due to the high electronegativity of fluorine, neither water nor water-containing substances wet PTFE. PTFE has the lowest coefficient of friction of all solids. Because PTFE is hydrophobic, the face mask 100 or mask 200 of the present invention does not lose efficiency even with prolonged use, whereas a face mask made purely of PP will lose its static charge after being worn for more than 4 hours. The advantage of the PP and PTFE combination mask is the microporous structure that develops when stretched, which is large enough to even prevent the penetration of bacteria and viruses through the inner layer 30 of masks 100 and 200.

[0039] The evaluation of the PTFE and PP layers of the inner layer 30 is as follows. Porosity of PTFE membrane: 45-90% PP nonwoven fabric weight: 10-40 gsm (grams / square meter) Thickness range of inner layer 30: 0.5 to 7 microns

[0040] The aforementioned ultrasonic welding should be understood to mean a technique well known and understood by those skilled in the art in the field of "ultrasonic soldering." Ultrasonic welding may be a lamination process or any other suitable bonding process for fiber bonding. Alternatively, the aforementioned ultrasonic welding can be achieved by ultrasonic slitting, i.e., by cleanly cutting and sealing the components of masks 100 and 200, thereby eliminating the defects of hot wire or rotary knife, fraying, unraveling, or beading along the cut edges. [Examples]

[0041] Criteria and results of effectiveness ASTM International, formerly known as the American Society for Testing and Materials, provides a guide for evaluating the appropriate level of face masks for various procedures. [Table 1]

[0042] ASTM F2100-19: The standard specification for the performance of materials used in medical face masks defines the requirements for medical face masks, subdivided into three categories. Threshold requirements are based on: percentage of bacterial filtration efficiency (BFE), percentage of particulate filtration efficiency (PFE), pass / fail status for splash resistance (mmHg), and pressure difference (mmH2O / cm²). 2 The pass / fail status for ΔP and flammability is as follows: [Table 2]

[0043] The test data for Mask 100 is shown in the table below. Please note that Mask 100 may have two different efficacy levels: ASTM F2100-19 / Level 2 compliant or ASTM F2100-19 / Level 3 compliant. The relevant test data for Mask 100 is summarized below. [Table 3] [Table 4]

[0044] The test data for Mask 200 is shown in the table below. Please note that Mask 200 may have two different efficacy levels: ASTM F2100-19 / Level 2 compliant or ASTM F2100-19 / Level 3 compliant. The relevant test data for Mask 200 is summarized below. [Table 5] [Table 6]

[0045] Canada no longer adheres to the ASTM international standard and instead follows new guidance from Health Canada, and both Mask 100 and Mask 200 comply with Health Canada's guidelines. Mask 200 also complies with the U.S. National Institute for Occupational Safety and Health standard for medical face masks with transparent windows. Mask 200 underwent bacterial cleanliness and cytotoxicity testing according to the International Organization for Standardization's ISO 10993-5 and ISO 10993-10 standards for medical devices, and Mask 200 passed both tests. The ISO 10993-5 test concerns culturing cultured cells directly or by diffusion in contact with the device and / or extracts of the device. The 10993-10 test concerns the evaluation of a medical device and its components for the potential to induce skin sensitization.

[0046] It will be understood that various aspects and other features and functions of the above disclosure, or their substitutes, may, preferably, be combined into many other different systems or applications. Various currently unforeseen or unforeseen substitutes, changes, modifications, or improvements may subsequently be made by those skilled in the art, but these too are intended to be covered within the following claims. [Explanation of Symbols]

[0047] Reference sign 10 Face masks 100, 200, first outer layer 11 Outer surface of the first outer layer 10 12. Opening of the first outer layer of face mask 200 12a Inner rim of opening 12 14 Upper edge of the first outer layer of face masks 100 and 200 16 Lower end of the first outer layer of face masks 100, 200 20 Face Masks 100, 200 Second Outer Layer 21 Face surface of the second outer layer 20 22 Opening of the second outer layer of face mask 200 22a Inner rim of opening 22 24 Upper edge of the second outer layer of face masks 100 and 200 26 Lower edge of the second outer layer of face masks 100 and 200 30 Face Masks 100, 200 Inner Layer 30a Face mask 100, 200 inner layer 30 PP layer 30b PTFE layer 30 for the inner layer of face mask 100, 200 32 Openings in the inner layer 30 of face mask 200 32a Opening of the PP layer 30a of the inner layer 30 of the face mask 200 32b Opening of the PTFE layer 30b of the inner layer 30 of the face mask 200 32c Inner rim of opening 32a 32d Inner rim of opening 32b 34 Upper edge of the inner layer of face mask 100, 200 36. Lower edge of the inner layer of face masks 100 and 200. 40 Ultrasonic welding part 401 Upper ultrasonic welding part 402 First side ultrasonic welding section 403 Second side ultrasonic welding section 404 Lower ultrasonic welding section 42 Sleeve ultrasonic welding section 441 Ear Loop Ultrasonic Welding Section 442 Ear Loop Ultrasonic Welding Section 443 Ear Loop Ultrasonic Welding Section 444 Ear Loop Ultrasonic Welding Section 48 Window ultrasonic welding section 501 Ear Loop 502 Ear Loop 60 windows 62 Window Covers 70 Nose Piece 72 Nose Piece Sleeve 74 Nose Piece Sleeve 72 Pockets 80 Lower Boundary Panel 82 Connection Panel 84 Upper boundary panel 86 Window Panel 100 PTFE and PP Combination Face Mask 200 PTFE and PP combination face masks with transparent windows P1-P6 Mask with 100 pleats P1'~P6' Mask with 200 pleats L1~L6 Mask 100 pleat lines L1'~L6' Pleated lines of mask 200 LE lower end UE upper end FS Filtration Section NS Nose Section US Upper Section PD proximal depth ID intermediate depth DD distal depth

Claims

1. a first polypropylene outer layer having a first opening disposed therein and contained within a respective peripheral edge of said first outer layer; a second polypropylene outer layer having a second opening disposed therein and contained within a respective peripheral edge of said second outer layer; an inner layer of polytetrafluoroethylene and polypropylene composite disposed between said first and second outer polypropylene layers, said inner layer having a third opening disposed therein and contained within a peripheral edge of each of said inner layers; at least one strap secured to an outer surface of one of the outer layers; A face mask comprising: a transparent window is disposed on an outer surface of one of the outer layers via a window welding portion, the transparent window overlapping an outer periphery of the opening of the outer layer and an outer periphery of the opening of the inner layer; The window weld is formed by fusing the outer layer and the inner layer adjacent to the outer periphery of the opening of the outer layer and the opening of the inner layer, A face mask, characterized in that the transparent window is surrounded by the outer layer and the inner layer between an outer periphery of the transparent window and peripheral edges of the outer layer and the inner layer, forming a space therebetween.

2. A first welded portion is arranged to fuse the outer periphery of the outer layer and the inner layer and is further arranged to pleat the outer layer and the inner layer; a flexible nose piece fixed within a sleeve formed by the folds of the first outer layer, the inner layer, and the second outer layer on either the outer surface of the first outer layer or the outer surface of the second outer layer via a sleeve weld; 10. The face mask of claim 1, further comprising:

3. 3. The face mask of claim 2, wherein the first weld and the sleeve weld are provided by ultrasonic welding techniques.

4. 3. The face mask of claim 2, wherein the first welds include a pair of horizontal welds and a pair of vertical welds, the pair of horizontal welds being positioned proximate a pair of vertically and parallel-disposed outer boundaries of the mask, and the pair of vertical welds being further positioned to pleat the outer layer and the inner layer.

5. The face mask of any one of claims 1 to 4, wherein the combination of the first polypropylene outer layer, the second polypropylene outer layer, and the inner layer of polytetrafluoroethylene and polypropylene composite has a bacterial filtration efficiency (BFE) of 100%.

6. The face mask of any one of claims 1 to 4, wherein the combination of the first polypropylene outer layer, the second polypropylene outer layer, and the inner layer of polytetrafluoroethylene and polypropylene composite has a particulate filtration efficiency (PFE) of greater than 98%.

7. 5. The face mask of claim 4, wherein the pair of vertical welds form pleats in the outer layer and the inner layer in a manner that creates four panels having three distinct depth levels, the depth levels including a distal depth, an intermediate depth, and a proximal depth.

8. The four panels are: a lower boundary panel disposed at the proximal depth; an upper border panel disposed at the intermediate depth; a connection panel disposed at the intermediate depth; a window panel disposed at the distal depth, the window panel comprising the opening in the outer layer, the opening in the inner layer, and the window; 8. The face mask of claim 7, wherein the upper border panel is integrally connected to the window panel, the window panel is integrally connected to the connecting panel, and the connecting panel is integrally connected to the lower border panel.

9. A face mask as described in any one of claims 1 to 4, 7 to 8, wherein the window weld is provided by ultrasonic welding technology.

10. The face mask according to any one of claims 1 to 4 and 7 to 8, wherein the transparent window is made of polyethylene.

11. 11. The face mask of claim 10, wherein the transparent window comprises about 99.79% polyethylene.

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