EP4150141A1

EP4150141A1 - Reusable fabric face mask and associated manufacturing process

Info

Publication number: EP4150141A1
Application number: EP21724683.4A
Authority: EP
Inventors: Laurent Breuil; Murielle CAPRARO
Original assignee: Thuasne SA
Current assignee: Thuasne SA
Priority date: 2020-05-15
Filing date: 2021-05-11
Publication date: 2023-03-22
Also published as: WO2021228833A1; FR3110055B1; FR3110055A1

Abstract

The invention relates to a mask comprising a main body (12) which comprises a filtering zone (18) suitable for covering the mouth and nose of a user, the filtering zone (18) being made of at least one layer of fabric, the fabric comprising warp yarns and weft yarns. The weft yarns comprise binder yarns, front yarns and back yarns, the binder yarns and the warp yarns together forming a central mesh of the fabric, the front yarns and the warp yarns forming a front mesh extending from a first side of the central mesh, the back yarns and the warp yarns forming a front mesh extending from a second side of the central mesh, the first and second sides of the central mesh being opposite each other depending on the thickness of the fabric.

Description

TITLE: Reusable woven barrier mask and associated manufacturing process

The present invention relates to a mask comprising a main body comprising a filtering zone, the filtering zone being adapted to cover the mouth and nostrils of a user, the filtering zone consisting of at least one layer of fabric, the fabric comprising weft yarns and warp yarns.

The invention further relates to a method of manufacturing such a mask.

There are currently two main types of masks for medical use, intended to cover the mouth and nostrils of a user.

On the one hand, surgical masks are intended to limit the transmission of infectious agents from a possible carrier to another person. They are class 1 medical devices, according to the EC directive. They must comply with standard NF EN 14683 + AC dating from August 2019 and relating to masks for medical use.

The majority of surgical masks are made on the basis of a non-woven fabric, which is made in the form of a rectangle with three folds. When the mask is worn, the three folds open, to adapt the mask to the wearer's face.

On the other hand, respirators, or particle filtering half-masks, are designed to protect a person from their environment. They are personal protective equipment (PPE) and must comply with standard NF EN 149 + A1 dating from September 2009 and relating to respiratory protection devices and filtering half-masks against particles.

They are also made from non-woven materials. Several shapes exist, for example the so-called “duckbill” and “shell” shapes.

However, these two types of masks have the major drawback of having to be replaced every 3 or 4 hours and of not being reusable.

This leads in particular to a waste treatment problem, more particularly in the event of heavy use of masks, for example in hospitals or in the event of an epidemic.

A new category of masks has been created, under the name of barrier masks.

Such a mask is expected to have a certain filtration capacity of the material used, a reduced breathing resistance of the material and a shape adapted to cover the user's face in order to avoid leakage problems as much as possible.

It is, for example, expected a bacterial filtration efficiency greater than or equal to 95%, more particularly for particles of 3 μm, and a differential pressure strictly less than 40 Pa per cm ² as defined in standard NF EN 14683 + AC dating from August 2019 and relating to masks for medical use. Such a differential pressure corresponds to a minimum admissible flow rate under a depression of 100 Pa of 139 L / m ² / s.

Such a mask is intended for use by healthy people who do not have clinical symptoms of viral infection and who are not in contact with people presenting such symptoms.

Its wearing makes it possible to constitute a protective barrier against a possible viral penetration or retention in the area of the mouth and nose of its user. It also makes it possible to protect said zone from any contact with the hands.

This mask makes it possible in particular to protect an entire group wearing such a type of barrier mask.

Masks are notably made by hand as part of the protection of a group.

However, these masks exhibit very variable filtration performance, which may turn out to be unsatisfactory.

An aim of the invention is to provide a mask designed to reduce the risk of general transmission of an infectious agent and offering satisfactory filtration performance.

To this end, the invention relates to a mask of the aforementioned type, in which the warp threads comprise binding threads, face threads and reverse threads, the binding threads forming together with the binding threads. weft a central grid of the fabric, the face threads forming with the weft threads a face grid extending from a first side of the central grid, the reverse threads forming with the weft threads a grid of backing extending from a second side of the center grid, the first side and the second side of the center grid being opposed in a thickness of the fabric.

The arrangement of the fabric in the form of three grids provides better filtration performance compared to a conventional fabric.

The mask may also have one or more of the characteristics below, considered individually or in any technically possible combination:

- the filtering zone comprises an inner face intended to be worn facing a user and an outer face intended to be oriented towards an external environment, the outer face being formed by the face yarns and the binding yarns, the yarns of location representing at least 50% of the outer face, the inner face being formed by the wires reverse side and binding yarns, the reverse yarns representing at least 50% of the inner face;

- the back yarns are on average more hydrophobic than the right yarns;

the weft yarns and the warp yarns are synthetic multifilament yarns each comprising at least twenty-three filaments;

- Each of the weft yarns and of the warp yarns has an elasticity strictly less than 20%;

- the filtering area consists of a single layer of fabric;

- the fabric has a weave having a pattern comprising a given number of rows, each row corresponding to one passage of a weft yarn, the pattern comprising at least one of the binding yarns, at least one of the reverse yarns and at least one of the face threads, the face thread (s) of the pattern considered together comprising at least one taken per row, the reverse thread (s) of the pattern considered together comprising at least one left per row, more particularly at least two left per row;

- the pattern comprises a plurality of reverse threads and a plurality of face threads, more particularly four reverse threads and four face threads, the pattern comprising a first type of row and a second type of row, the rows of the first type of row alternating with the rows of the second type of row, a row of the first type comprising four takes formed by the face threads and two left formed by the reverse threads on the pattern, a row of the second type comprising a take formed by the face threads and four left formed by the reverse threads on the pattern;

- the fabric frame pattern has eight rows and includes:

- a first binding thread forming a catch on each of the second, fourth, fifth and eighth rows and one left on each of the first, third, sixth and seventh rows,

- a second binding thread forming a catch on each of the first, fourth, sixth and eighth rows and one left on each of the second, third, fifth and seventh rows,

- a first right thread forming a catch on each of the second, fourth, sixth, seventh and eighth rows and one left on each of the first, third and fifth rows,

- a second place thread forming a catch on each of the second, third, fourth, sixth and eighth rows and one left on each of the first, fifth and seventh rows, - a third place thread forming a catch on each of the second, fourth, fifth, sixth and eighth rows and one left on each of the first, third and seventh rows,

- a fourth right thread forming a catch on each of the first, second, fourth, sixth and eighth rows and one left on each of the third, fifth and seventh rows,

- a first reverse thread forming a catch on each of the second and fourth rows and one left on each of the first, third, fifth, sixth, seventh and eighth rows,

- a second reverse thread forming a catch on each of the second and eighth rows and one left on each of the first, third, fourth, fifth, sixth and seventh rows,

- a third reverse thread forming a take on each of the sixth and eighth rows and one left on each of the first, second, third, fourth, fifth and seventh rows, and

- a fourth reverse thread forming a take on each of the fourth and sixth rows and one left on each of the first, second, third, fifth, seventh and eighth rows.

The invention further relates to a method of manufacturing a mask as defined above, comprising the following steps:

- weaving of at least one layer of fabric, the fabric comprising weft threads and warp threads, the warp threads comprising binding threads, face threads and reverse threads, binding threads forming together with the weft threads a central grid of the fabric, the face threads forming with the weft threads a face grid extending from a first side of the central grid, the reverse threads forming with the weft threads weft yarns a reverse grid extending from a second side of the central grid, the first side and the second side of the central grid being opposed according to a thickness of the filtering zone, and

- production of a mask comprising a main body comprising a filtering zone, the filtering zone being adapted to cover the mouth and nostrils of a user, the filtering zone consisting of at least one layer of fabric.

The manufacturing process of the invention may further comprise a step of stabilizing at least one layer of fabric after weaving, the stabilizing step comprising passing the fabric through water vapor.

Other characteristics and advantages of the invention will become apparent on reading the following description of embodiments of the invention, given by way of example only and with reference to the drawings in which: [Fig 1] Figure 1 is a perspective view of a mask according to one embodiment of the invention, worn by a user,

[Fig 2] Figure 2 is a schematic view of a weave of a fabric structure according to an example of the invention, and

[Fig 3] Figure 3 is a cross-sectional view of the fabric structure of Figure 2.

An example of a mask 10 according to the invention is shown in Figure 1.

The mask is intended to be worn by a user to cover the area of the mouth and nose, more particularly the nostrils, so as to filter the air entering and / or leaving the user's mouth and nose relative to to its external environment.

The mask 10 comprises a main body 12 and at least one holding member 14, 16 of the main body 12.

By "transverse direction" is meant the direction intended to extend transversely to the face of the wearer when the mask is worn.

The main body 12 includes a filter zone 18.

The main body 12 further comprises an upper part 20.

More particularly, the main body 12 comprises edges surrounding the whole of the filtering zone 18, the upper part 20 defining the upper edge of the filtering zone 18.

The filtering zone 18 is adapted to cover, that is to say to extend in front of, the mouth and nostrils of a user.

The filtering zone 18 has in particular a shape and dimensions adapted to cover the area of the mouth and nostrils of a possible wearer.

The filtering zone 18 comprises an inner face intended to be worn facing the user and an outer face 22 intended to be oriented towards an external environment.

In the example shown, the main body 12 has the general so-called duckbill shape.

The main body 12 includes, for example, an upper portion 24 and a lower portion 26 together forming a spout.

The main body 12 is, for example, made up of a single textile piece folded over at a fold 28 forming the tip of the spout and delimiting the upper portion 24 and the lower portion 26.

The side edges of the textile piece of the lower portion 26 and of the upper portion 24 are joined, for example over their entire length, for example by sewing, so as to close the duckbill shape on the sides. Such a form of mask is pleasant for the user because the spout forms an air pocket in front of the user's mouth. Furthermore, a mask having such a shape is easy to produce from a textile part.

The filtering zone 18 here consists of at least one layer of fabric of threads, more particularly here of a single layer of fabric.

The fabric is here woven flat.

The yarns are, for example, synthetic multifilament yarns.

Each thread forming the fabric comprises at least twenty-three filaments.

More particularly, each thread of the fabric comprises at least one end.

In the event of a plurality of ends for a yarn, they are assembled, preferably by twisting.

Each end includes at least twenty-three filaments.

The fabric of the filtering zone 18 is, for example, woven on a loom comprising a comb having at least 7 teeth per centimeter, more particularly having between 7 and 10 teeth per centimeter, more particularly having 9 teeth per centimeter.

The fabric of the filtering zone has a pick, for example produced on a loom, of between 7 and 15 picks per centimeter, more particularly equal to 14.5 picks per centimeter.

This makes it possible in particular to obtain very tight meshes, particularly suitable for the filtration of infectious agents.

Synthetic multifilament yarns are, for example, made of polyamide, polyester or polypropylene.

Polyamide, polyester or polypropylene in particular has a relatively low moisture uptake rate, which makes it possible in particular to limit any risk of bacteria developing, linked to residual moisture.

Each of the synthetic multifilament yarns has an elasticity strictly less than 20%.

This makes it possible in particular to limit the deformation of the fabric in the filtering zone 18, for example during the wearing of the mask, and therefore of the size of the pores formed by the fabric. This helps maintain the filtration properties of the mask.

The titer of a yarn expressed in tex is the mass in grams of a thousand meters of this yarn.

The titer of each yarn is, for example, between 44 dtex and 500 dtex, more particularly between 65 dtex and 350 dtex.

The fabric usually comprises warp yarns and weft yarns. The warp yarns here include, more particularly are made up of face yarns i3, i4, i5, i6, reverse yarns i7, i8, i9, i10 and binding yarns il, i2.

The binding yarns il, i2 and the weft yarns together form a central grid.

The central grid has a first side and a second side opposite depending on the thickness of the fabric.

The thickness here corresponds to the direction in which the fabric passes between the outer face 22 and the inner face.

The right side yarns i3, i4, i5, i6 together with the weft yarns form a right side grid extending from a first side of the central grid.

The reverse threads i7, i8, i9, i10 together with the weft threads form a reverse grid extending from the second side of the central grid.

The outer face 22 is formed by the place yarns i3, i4, i5, i6 and the binding yarns

11, i2, the son of places i3, i4, i5, i6 representing at least 50% of the outer face, more particularly at least 66% of the outer face.

The inner face is formed by the reverse yarns i7, i8, i9, i10 and the binding yarns il,

12, the reverse threads representing at least 50% of the inner face, more particularly at least 75%, more particularly at least 80% of the inner face.

More particularly, the fabric includes the center grid, the right grid and the back grid.

The three screens improve the filtration performance of the fabric compared to fabric without such an arrangement. A mask having such a fabric with three grids in a filtering zone makes it possible to obtain performance similar or superior to that of a mask comprising a plurality of layers of fabric not having such an arrangement.

The weft threads are, for example, similar to each other and, in particular, are made from the same material, comprise a given number of assembled ends, have a given count and a given number of filaments per end.

The face yarns i3, i4, i5, i6 are, for example, similar to each other and, in particular, are made of the same material, include a given number of assembled ends, have a given count and a given number of filaments per end.

The reverse yarns i7, i8, i9, i10 are, for example, similar to each other and, in particular, are made of the same material, include a given number of assembled ends, have a given count and a given number of filaments per end.

The binding yarns il, i2 are, for example, similar to each other and, in particular, are made from the same material, comprise a given number of assembled ends, have a given count and a given number of filaments per end. The binding yarns il, i2 are, for example, similar to the face yarns i3, i4, i5, i6, that is to say they are made of the same material, have the same number of ends per yarn, the same number of filaments per end and the same count.

The binding yarns il, i2 are, for example, made of polyamide.

The given number of ends per binding thread il, i2 is more particularly equal to 4.

The binding yarns il, i2 have, for example, a count of between 44dtex and 100 dtex, more particularly equal to 78 dtex.

The binding yarns 11, i2 here comprise 68 filaments per end.

The right yarns i3, i4, i5, i6 are, for example, made of polyamide.

The given number of ends per thread from place i3, i4, i5, i6 is more particularly equal to 4.

The place children i3, i4, i5, i6 have, for example, a titer of between 44dtex and 100 dtex, more particularly equal to 78 dtex.

The place yarns i3, i4, i5, i6 here include 68 filaments per end.

The reverse threads i7, i8, i9, i10 are, for example, made of polyester.

The given number of ends per reverse thread i7, i8, i9, i10 is more particularly equal to 1.

The reverse threads i7, i8, i9, i10 have, for example, a titer of between 300 dtex and 350 dtex, more particularly equal to 330 dtex.

The reverse threads i7, i8, i9, i10 here each include 576 filaments.

The weft threads are, for example, made of polyester.

The given number of ends per weft thread is more particularly equal to 2.

The weft threads have, for example, a count of between 300 dtex and 350 dtex, more particularly equal to 330 dtex.

The weft threads here comprise 48 filaments per end.

Advantageously, the threads forming the inner face of the filtering zone 18 are on average more hydrophobic than the threads forming the outer face 22 of the filtering zone 18 over the whole of the filtering zone 18.

In particular, this allows moisture to be transferred from the wearer's face to the outside by capillary action, thereby improving the comfort of wearing the mask.

The reverse yarns i7, i8, i9, i10 are, for example, strictly more hydrophobic than the right yarns i3, i4, i5, i6.

The binding yarns il, i2 have, for example, a hydrophobicity between that of the right yarns i3, i4, i5, i6 and that of the reverse yarns i7, i8, i9, M 0.

The filter zone 18 has a fabric weave with a pattern.

The fabric weave pattern is repeated over the entire filter area 18. The pattern is made on a given number of rows and warp threads.

Each row corresponds to one passage of a weft thread.

The pattern, especially the rows of the pattern, are repeated along the warp direction of the fabric.

The pattern, more particularly the warp threads of the pattern, are repeated along the weft direction of the fabric.

The or all of the right yarns of the pattern considered together i3, i4, i5, i6 includes at least one taken per row.

More specifically, the set of right side threads of the pattern taken together i3, i4, i5, i6 includes one taken for every second row and four taken for the other row out of two.

The or all of the reverse threads of the pattern considered together i7, i8, i9, i10 comprises at least one left per row, more particularly at least two left per row.

More particularly, the set of reverse threads of the pattern taken together i7, i8, i9, i10 includes two left for every second row and four left for the other row of two.

More particularly, for every second row said first type of row, the set of face threads of the pattern considered together i3, i4, i5, i6 comprises a take and the set of reverse threads of the pattern considered together i7 , i8, i9, i10 includes four left; and on the other row out of two called the second type of row, the set of face threads of the pattern considered together i3, i4, i5, i6 comprises four takes and the set of reverse threads of the pattern considered together i7 , i8, i9, i10 includes two left.

The rows of the first row type alternate with the rows of the second row type.

An example of a pattern according to the invention is shown in Figures 2 and 3.

The reinforcement pattern is made here over eight rows and ten warp threads il, i2, i3, i4, i5, Î6, Î7, Î8, Î9, il 0.

Each pattern here comprises a plurality of binding yarns il, i2 and / or, here and, a plurality of face yarns i3, i4, i5, i6 and / or, here and, a plurality of reverse yarns i7, i8, i9, i10.

More particularly, in the example shown, each pattern comprises, more particularly in this order, two binding yarns il, i2, four face yarns i3, i4, i5, i6 and four reverse yarns i7, i8, i9 , i10.

The weft threads are shown in section in Figure 3.

Each binding thread 11, i2 forms four taken and four left (or skipped) on the eight rows of the pattern. Each right yarn i3, i4, i5, i6 forms five takes and three left out of the eight rows of the pattern.

Each reverse thread i7, i8, i9, i10 forms two takes and six left in the eight rows of the pattern.

A first tying thread it forms taken on the second, fourth, fifth and eighth rows and left on the first, third, sixth and seventh rows.

A second binding thread i2 forms taken on the first, fourth, sixth and eighth rows and left on the second, third, fifth and seventh rows.

A first right yarn i3 forms grips on the second, fourth, sixth, seventh and eighth rows and leftovers on the first, third and fifth rows.

A second right yarn i4 forms catches on the second, third, fourth, sixth and eighth rows and leaves on the first, fifth and seventh rows.

A third right thread i5 forms grips on the second, fourth, fifth, sixth and eighth rows and leaves on the first, third and seventh rows.

A fourth right thread i6 forms grips on the first, second, fourth, sixth and eighth rows and leaves on the third, fifth and seventh rows.

A first reverse thread i7 forms grips on the second and fourth rows and leaves on the first, third, fifth, sixth, seventh and eighth rows.

A second reverse thread i8 forms picks on the second and eighth rows and leaves on the first, third, fourth, fifth, sixth and seventh rows.

A third reverse thread i9 forms prizes on the sixth and eighth rows and leaves on the first, second, third, fourth, fifth and seventh rows.

A fourth reverse thread i10 forms picks on the fourth and sixth rows and leaves on the first, second, third, fifth, seventh and eighth rows.

The fabric has, for example, a surface mass strictly greater than 400 g / m ² , more particularly between 400 g / m ² and 600 g / m ² , more particularly between 450 g / m ² and 550 g / m 2. In the case of a fabric as described above and dimensionally stabilized as described below, in particular made with the yarns described and having a weave pattern according to Figures 2 and 3, the following values were measured for a single fabric layer:

- air permeability for a depression of 100 pascals: 154 liters per square meter per second,

- retention of projections for particles having a size of 3 μm: 98%, and

- retention of projections for particles having a size of 1 μm: 93%.

These values were measured according to the corresponding protocol described in the guide to minimum requirements, test methods, manufacture and use for barrier masks by AFNOR under the reference AFNOR SPEC S76-001, version 1.10 of April 27. 2020.

The retention values of the projections were measured for a flow from the inside to the outside, that is to say corresponding to a flow from a wearer towards its external environment.

These values are in line with the expected values, in particular as regards the air permeability for a depression of 100 pascals and the retention of projections for particles having a size of 3 μm, for masks of the "barrier" type.

Thus, the filtering zone formed by a layer of said fabric offers a level of filtration in accordance with the values expected for "barrier" type masks.

Consider a maintenance cycle consisting of washing at a temperature of 60 ° C during a 60 minute wash cycle, drying in a mechanical dryer at 70 ° C during a 60 minute drying cycle and ironing with steam.

After 30 maintenance cycles, the following values were measured for a single layer of the same fabric as before:

- air permeability for a depression of 100 pascals: 102 liters per square meter per second,

- retention of projections for particles having a size of 3 μm: 100%, and

- retention of projections for particles having a size of 1 μm: 100%.

After 45 maintenance cycles, the following values were measured for a single layer of the same fabric as before:

- air permeability for a depression of 100 pascals: 105 liters per square meter per second,

- retention of projections for particles having a size of 3 μm: 99%, and

- retention of projections for particles having a size of 1 μm: 99%. The fabric therefore maintains satisfactory levels of air permeability and spatter retention.

A mask whose filtering zone is produced by a layer of said fabric is washable at least 45 times at 60 ° C. Such a temperature eliminates many infectious agents.

The mask is therefore reusable.

In addition, with a single layer of fabric, comparable or even better filtration performance is obtained than textiles comprising several layers of fabric, while offering lower inspiratory resistance.

The upper part 20 has a tubular zone delimiting a tube.

The upper part 20 is, for example, woven adjacent to the upper edge of the filter zone 18, in the form of a tube with a tubular fabric.

Alternatively, the tubular zone of the upper part 20 is produced by a flap of the fabric on itself in the upper part 20.

The tube has a main direction of extension in the transverse direction.

A nasal bar 30 is arranged in the tube.

The nose bar 30 is arranged in the main direction of extension of the tube.

The nasal bar 30 is intended to extend transversely over the nose of a wearer of the mask.

The nasal bar 30 is malleable so as to form and maintain a desired shape.

This makes it possible in particular to give the mask a given shape at its upper part, so as to conform to the relief formed by the nose, and thus limit the risk of leakage around the filtering zone 18.

The nasal bar 30 is, for example, metallic.

The at least one retainer 14, 16 is provided to hold the main body 12 to the face of a wearer.

The at least one retainer 14, 16 allows for easy placement and removal of the main body 12 on the face.

The at least one retaining element 14, 16 comprises at least one link, for example an elastic strap, connecting a first transverse side and a second transverse side of the main body, said link being adapted to surround the back of the head of the body. 'an user.

In the example shown, the at least one retaining element comprises an upper link 14 and a lower link 16, each connecting the first transverse side and the second transverse side of the main body, each link being intended to surround the rear of the body. the head of a user. Alternatively, the at least one retaining element 14, 16 comprises, for example, elastic straps extending from each transverse side of the main body 12, each elastic strap being intended to surround an ear of the wearer.

A method of manufacturing a mask according to an embodiment of the invention will now be described.

The manufacturing process comprises a step of weaving at least one layer of fabric, more particularly a single layer of fabric, intended to form the filtering zone 18.

The fabric is, for example, woven as described above.

The fabric is made on a loom.

The loom here has a pick of between 7 and 15 picks per centimeter, more particularly equal to 14.5 picks per centimeter.

An upper part 20 is arranged at an upper edge of the filtering zone 18, more particularly is woven from the upper edge of the filtering zone 18, so as to define a tubular zone.

Alternatively, the fabric is folded in the upper part 20 to form a tubular zone

The manufacturing process includes a step of making the mask from at least one layer of fabric.

The filtering zone 18 consists of at least one layer of fabric, more particularly of the single layer of fabric.

The upper part 20 is arranged at the level of the upper edge of the filtering zone

18.

The production step here comprises a sub-step of shaping the at least one layer of fabric.

The at least one layer of fabric is, for example, shaped to present the so-called duckbill shape.

The at least one layer of fabric is, for example, folded over at a fold 28 delimiting an upper portion 24 and a lower portion 26.

The fold 28 is here substantially parallel to the upper edge of the filtering zone.

The side edges of the at least one layer of fabric of the lower portion 26 and of the upper portion 24 are secured, for example over their entire length, for example by sewing, so as to close the duckbill shape on the sides. sides.

The production step further comprises, for example, a sub-step of adding at least one holding element 14, 16 and / or a nasal bar 30. The at least one retaining element 14, 16 is added to the main body 12 as described above with regard to the mask 10.

The nasal bar 30 is inserted into the tube formed in the upper part 20.

The manufacturing process advantageously comprises a step of stabilizing the fabric after weaving.

More particularly, at least one layer of fabric forming the filtering zone 18 and possibly the upper part 20 has undergone (ssen) the stabilization step.

The stabilization step involves passing the fabric through water vapor.

The passage of the fabric in the water vapor has a duration greater than or equal to one minute, more particularly equal to one minute.

The water does not contain any impregnation product or auxiliary treatment product.

The passage of the fabric through the water vapor is, for example, carried out on a continuous treatment line.

The stabilization step is, for example, carried out before the step of making the mask from at least one layer of fabric.

The stabilization operation makes it possible in particular to stabilize the fabric dimensionally, that is to say that the fabric does not deform subsequently, especially when washing. In particular, this allows the mask to maintain compliant filtration capacities and respiratory resistance.

In an alternative embodiment not shown, the mask has a so-called three-ply shape. During the shaping substep, at least one layer of fabric is, for example, shaped into a three-ply shape. For example, the side edges of the at least one layer of fabric are sewn so as to form folds, for example three folds but possibly two or more than three, capable of opening to adapt to the face of a person. carrier.

The filtering zone of the mask according to the invention makes it possible to filter the air between the outside and the zone of the mouth and the nose of a wearer of the mask, so as to reduce the risk of an infectious agent among a group of people who wear the mask.

The production of a fabric having a weave forming three grids makes it possible to obtain, with a single layer of fabric, compliant filtration performance, in particular unlike the fabrics used in artisanal masks which require a plurality of layers to obtain satisfactory filtration performance. .

The use of a single layer of this fabric to make a mask makes it possible in particular to reduce the thickness of the filtering zone compared to a mask made with starting from several layers of fabric and obtaining a lower breathing resistance, which makes wearing the mask less inconvenient for the user.

This allows in particular that the user does not remove or give up wearing his mask out of discomfort and contributes to the good protection of a group of people wearing the mask according to the invention.

Claims

1. Mask (10) comprising a main body (12) comprising a filtering zone (18), the filtering zone (18) being adapted to cover the mouth and nostrils of a user, the filtering zone (18) consisting of 'at least one layer of fabric, the fabric comprising weft threads and warp threads (il, i2, i3, i4, i5, i6, i7, i8, i9, il 0), characterized in that the threads of warp (il, i2, i3, i4, i5, i6, i7, i8, i9, il 0) include binding yarns (il, i2), face yarns (i3, i4, i5, i6) and reverse threads (i7, i8, i9, M 0), the binding threads (il, i2) forming together with the weft threads a central grid of the fabric, the face threads (i3, i4, i5, i6 ) forming with the weft threads a face grid extending from a first side of the central grid, the reverse threads (i7, i8, i9, M 0) forming with the weft threads a grid of backing extending from a second side of the central grille, the first side and the second side of the central grille being opposites according to a thickness of the fabric.

2. Mask according to claim 1, wherein the filtering zone (18) comprises an interior face intended to be worn facing a user and an exterior face (22) intended to be oriented towards an exterior environment, the exterior face (22). being formed by the face threads (i3, i4, i5, i6) and the binding threads (il, i2), the face threads (i3, i4, i5, i6) representing at least 50% of the face outer (22), the inner face being formed by the reverse yarns (i7, i8, i9, M 0) and the binding yarns (il, i2), the reverse yarns (i7, i8, i9, il 0) representing at least 50% of the inner face.

3. Mask according to claim 2, wherein the reverse threads (i7, i8, i9, il 0) are on average more hydrophobic than the face threads (i3, i4, i5, i6).

4. Mask according to any one of claims 1 to 3, wherein the weft son and the warp son (il, i2, i3, i4, i5, i6, i7, i8, i9, il 0) are son synthetic multifilaments each comprising at least twenty-three filaments.

5. Mask according to any one of claims 1 to 4, wherein each of the weft threads and the warp threads (il, i2, i3, i4, i5, i6, i7, i8, i9, il 0) has a elasticity strictly less than 20%.

6. Mask according to any one of claims 1 to 5, wherein the filtering zone (18) consists of a single layer of fabric.

7. Mask according to any one of claims 1 to 6, wherein the fabric has a weave having a pattern comprising a given number of rows, each row corresponding to one passage of a weft yarn, the pattern comprising at least one of the binding yarns (il, i2), at least one of the reverse yarns (i7, i8, i9, M 0) and at least one of the right-hand yarns (i3, i4, i5, i6), the right-side yarn (s) of the pattern considered together (i3, i4, i5, i6) comprising at least one taken per row, the yarn (s) of reverse side of the pattern considered together (i7, i8, i9, il 0) comprising at least one left per row, more particularly at least two left per row.

8. Mask according to claim 7, wherein the pattern comprises a plurality of reverse threads (i7, i8, i9, M 0) and a plurality of face threads (i3, i4, i5, i6), more particularly four reverse threads (i7, i8, i9, M 0) and four right side threads (i3, i4, i5, i6), the pattern comprising a first type of row and a second type of row, the rows of the first row type alternating with rows of the second row type, a row of the first type comprising four takes formed by the right side threads (i3, i4, i5, i6) and two left formed by the reverse threads (i7, i8, i9, M 0) on the pattern, a row of the second type comprising a take formed by the right side threads (i3, i4, i5, i6) and four left formed by the reverse threads (i7, i8, i9, il 0) on the pattern.

9. Mask according to claim 7 or 8, wherein the fabric frame pattern has eight rows and comprises:

- a first binding thread (it) forming a catch on each of the second, fourth, fifth and eighth rows and one left on each of the first, third, sixth and seventh rows,

- a second binding thread (i2) forming a catch on each of the first, fourth, sixth and eighth rows and one left on each of the second, third, fifth and seventh rows,

- a first right thread (i3) forming a catch on each of the second, fourth, sixth, seventh and eighth rows and one left on each of the first, third and fifth rows,

- a second right thread (i4) forming a catch on each of the second, third, fourth, sixth and eighth rows and one left on each of the first, fifth and seventh rows,

- a third right thread (i5) forming a catch on each of the second, fourth, fifth, sixth and eighth rows and one left on each of the first, third and seventh rows,

- a fourth place thread (i6) forming a catch on each of the first, second, fourth, sixth and eighth rows and one left on each of the third, fifth and seventh rows, - a first reverse thread (i7) forming a catch on each of the second and fourth rows and one left on each of the first, third, fifth, sixth, seventh and eighth rows,

- a second reverse thread (i8) forming a catch on each of the second and eighth rows and one left on each of the first, third, fourth, fifth, sixth and seventh rows,

- a third reverse thread (i9) forming a catch on each of the sixth and eighth rows and one left on each of the first, second, third, fourth, fifth and seventh rows, and

- a fourth reverse thread (i10) forming a take on each of the fourth and sixth rows and one left on each of the first, second, third, fifth, seventh and eighth rows.

10. A method of manufacturing a mask (10) according to any one of claims 1 to 9, comprising the following steps:

- weaving of at least one layer of fabric, the fabric comprising weft threads and warp threads (il, i2, i3, i4, i5, i6, i7, i8, i9, il 0), warp threads (il, i2, i3, i4, i5, i6, i7, i8, i9, il 0) including binding yarns (il, i2), face yarns (i3, i4, i5, i6) and yarns reverse (i7, i8, i9, il 0), the binding threads (il, i2) together with the weft threads forming a central grid of the fabric, the face threads (i3, i4, i5, i6) forming with the weft threads a face grid extending from a first side of the central grid, the reverse threads (i7, i8, i9, il 0) forming with the weft threads a reverse grid extending from a second side of the central grid, the first side and the second side of the central grid being opposed according to a thickness of the filtering zone, and

- production of a mask (10) comprising a main body (12) comprising a filtering zone (18), the filtering zone (18) being adapted to cover the mouth and the nostrils of a user, the filtering zone (18) consisting of the at least one layer of fabric.

11. The manufacturing method according to claim 10, comprising a step of stabilizing at least one layer of fabric after weaving, the stabilization step comprising passing the fabric through water vapor.