WO2021198737A1

WO2021198737A1 - Washable protective mask, method for its production, method for washing the mask and for the restoration of its barrier properties

Info

Publication number: WO2021198737A1
Application number: PCT/IB2020/053188
Authority: WO
Inventors: Giorgio RIZZATO
Original assignee: Master 3 Srl
Priority date: 2020-04-01
Filing date: 2020-04-03
Publication date: 2021-10-07
Also published as: IT202000006811A1

Abstract

A protective mask (10) that is washable and reusable after the restoration of its barrier and biocidal properties. The patent also regards the method of constructing the mask and the method of washing and restoring its properties.

Description

WASHABLE PROTECTIVE MASK, METHOD FOR ITS PRODUCTION, METHOD FOR WASHING THE MASK AND FOR THE RESTORATION OF ITS

BARRIER PROPERTIES DESCRIPTION

The present patent relates to protective masks and in particular concerns a new washable protective mask, the method for its production, and a new method for washing a protective mask and restoring its barrier properties.

Protective masks are known in the prior art and are commonly used as a protective device in numerous sectors, including in the health and hygiene field as a barrier for possible bacterial and viral infections.

In particular, the prior art comprises masks made of sheets of fabric or other materials which are applied in front of a user's mouth and nose to prevent the passage of microorganisms, such as bacteria and viruses.

So-called "surgical" masks are well-known and widely used. They are normally made of two or three layers of non-woven fabric, for example polyester or polypropylene fibers, which filter the outgoing air and protect against splashes of liquid, such as the saliva emitted with coughing or sneezing which can carry viruses and bacteria.

The sheets of non-woven fabric are sewn together and are applied to the user's head by means of ties and/or elastic.

These masks are relatively inexpensive and are of the disposable type, since any washing operations would deprive them of their waterproof properties, voiding or in any case limiting the barrier effect.

Furthermore, if a pathogen were to land on the mask, the latter would be irreparably contaminated. For this reason, these masks, once used, require particular caution during their transfer to waste and subsequent treatment.

Masks which are reusable a certain number of times, as they can be sanitized after each use with suitable sanitizing sprays, are also known in the prior art. Such masks are generally more expensive and are normally reserved for healthcare professionals. More sophisticated and even more expensive masks are also known, equipped with interchangeable filters, the use of which is recommended only for expert personnel since improper and careless use could even void the effectiveness of the mask.

The object of this patent is a new washable and reusable protective mask, the method for its production, and the method of washing and restoring the barrier properties of the mask.

The main object of the new mask is to block up to 99% of pathogens, while being structurally simple and inexpensive, and also to be washable and reusable, after restoring its barrier properties.

The new mask can in fact be washed and treated by applying a stabilized alcoholic biocide gel which restores the barrier properties and reduces the pathogenic load after each use.

Another object of the present invention is to be light and usable by anyone, therefore intended for mass consumption.

These and other objects, direct and complementary, are achieved by the new washable and reusable protective mask, the method for its production, and the method of washing and restoring the barrier properties of the mask.

The new protective mask includes in its main parts a flexible sheet, of at least sufficient size to cover part of a user's face and in particular nose and mouth, where said sheet in turn comprises: a first layer, made of a washable material, for example and preferably made of cotton fabric, intended to be in contact with the user's skin; a second layer with a predominant physical barrier function, preferably made of washable material, such as and preferably non-woven fabric, with high external barrier resistance, constrained to said first layer; a third protective layer placed above the second breathable layer, with microporosity characteristics, such as, for example, a very thin sheet of cotton fabric, also already attached to the external surface of the second layer, that is, applied on said second layer on the opposite side from said first layer; a fourth layer applied at least on the surface of said third layer facing outwards, that is, on the side opposite the user's face, and where said last layer is in whole or in part made of a substance with a biocidal function; said last layer is in particular formed by a stabilized hydroalcoholic gel, which will be adequately sprayed and which will penetrate the microporosities of the previous layer; the spray will completely humidify the external surface, causing it to appear "translucent".

The biocidal substance is understood to be, for example, a preparation based on ethyl and/or isopropyl alcohol, for example comprising: ethyl and/or isopropyl alcohol, glycerol, 3% hydrogen peroxide, distilled water, with the addition of a stabilizer and thickener.

The mask therefore ensures a high reduction of the bacterial load thanks to a combined action of the physical barrier and biocidal barrier, the latter exercised by said third and fourth layer.

Said first layer has a thickness preferably between 0.5 and 0.6 mm, sufficient to ensure adequate support and resistance, as well as an initial barrier effect.

Said second layer has a thickness preferably between 0.6 and 0.8 mm, sufficient to ensure an adequate barrier effect.

Said third layer, which may already be attached as the external wall of the previous layer, will have a minimum thickness, predictably between 0.1 and 0.3 mm.

Said last layer has a thickness preferably between 0.1 and 0.2 mm, sufficient to ensure its biocidal action.

The overall thickness of the mask is therefore between 1.2 and 1.9 mm. The mask is therefore very light and comfortable and can be worn by anyone.

The mask also includes means for being correctly positioned and constrained in front of the user's nose and mouth, such as, for example, in a very simple and inexpensive embodiment, ties, elastic or non-elastic, to be tied behind the user's head or to be constrained to the user's ears, or to be positioned directly over a washable elastic cotton band, which will form said first layer.

Said second layer is suitably constrained to said first layer by any known method, for example by molding, gluing, heat-sealing or more preferably by sewing.

Said third layer is suitably constrained to said first layer by any known method, for example by molding, gluing, heat-sealing or more preferably by sewing.

Said last layer is applied on said third layer by spreading or spraying or another suitable system to soak the layer.

The method for making the new protective and washable mask which is the object of this patent includes the steps of: assembly of said first and second layers; application of said third layer on said second layer application of said last layer on third layer.

Said last layer is suitably colored or in any case has a different color or sheen from said third layer, so as to make its correct and complete application visible to the user. The method of washing and restoring the barrier functions of said mask includes the following steps:

- washing with at least one sanitizing agent; said sanitizing agent is for example a common oxygen-release sanitizing agent, widely available and widely used also in the home; it is preferable that the washing takes place at a low temperature, that is, that it takes place with washing liquid or water at a temperature generally not higher than 30°C; this washing phase sanitizes the mask, causes the last layer to wash away but does not compromise the other mechanical and physical characteristics of the mask; application of said fourth layer on said third layer, by spreading or spraying or generally applying a coat of said stabilized hydroalcoholic gel directly on said third layer.

This method restores the functionality of the mask in a simple and immediate way, without requiring specialized treatments and without using dangerous substances. Therefore this method can be applied by anyone, even and above all by non-expert people.

This method can be repeated multiple times without compromising the effectiveness of the mask.

The method may also include a further sterilization step, for example by using ultraviolet germicidal irradiation and ozone sterilization. The latter procedure is cold and sterilizes the mask, but obviously it does not clean it.

The characteristics of the new protective and washable mask will be better clarified by the following description with reference to the drawing, attached by way of a non limiting example.

Figure 1 schematically shows a plan view of the mask (10) in a simple and inexpensive embodiment thereof, particularly showing the ties (2) and the central part or sheet (1) intended to cover the user's face, that is, at least the mouth and nose.

Said ties (2) are for example obtained directly from the first layer making up said sheet (1).

Figure 2 shows a section of a schematic diagram of said sheet (1), showing the four layers (3, 4, 5, 6) that comprise it.

The new protective mask (10) comprises a flexible sheet (1), of a sufficient size to cover part of a user's face and in particular the nose and mouth.

In a very simple embodiment, by way of example, said sheet (1) has for example a substantially rectangular or square shape with a horizontal side (11), which is intended to be placed horizontally with respect to a user's face, and which for example may have a width equal to 160 mm and a vertical side (12) with a height of for example, 140 mm.

Said sheet (1) is preferably made up of at least four layers (3, 4, 5, 6).

A first support layer (3) is intended to be placed in contact with the user. Said first layer (3) is made of washable material, for example and preferably made of cotton fabric, perhaps also of stretch cotton, and preferably suitable for use in contact with the skin. Said first layer, if made of cotton, is preferably made of Egyptian cotton with 30-40 mm fibers, with a thickness between 0.5 and 0.6 mm.

The mask (10) also comprises ties (2) to secure the mask (10) to the user's face.

In the example in Figure 1, said ties (2) are obtained from said first layer (3) or are sewn or otherwise constrained along the two opposite horizontal sides (11) of said sheet (1).

This configuration has the advantage of being particularly simple to manufacture.

A second layer (4) is in any case constrained to the surface (32) of said first layer (3) opposite the surface (31) intended to be in contact with the user's face. For example, said second layer (4) is sewn to said first layer (3) or is constrained or in any case bonded to said first layer (3).

Said second layer (4) is preferably made of washable non-woven fabric or another similar material currently used for air filters, with a thickness between 0.6 and 0.8 mm.

A third layer (5) is applied at least on the surface (41) of said second layer (4) facing outwards, that is, opposite the side in contact with the user's face. It is made of a microporous fabric to facilitate the proper adhesion of the stabilized hydroalcoholic gel making up the last layer (6). Said last layer has a thickness preferably between 0.1 and 0.2 mm, sufficient to ensure its biocidal action.

Therefore, with reference to the preceding description and the attached drawings the following claims are made.

Claims

1. Protective mask (10) comprising a flexible sheet (1), of a sufficient size to cover part of a user's face and in particular at least the nose and mouth, and means (2) for positioning and constraining said sheet (1) on said face of the user, characterized in that said sheet (1) in turn comprises: a first layer (3) of washable material, with a first surface (31) intended to be in contact with the face of the user; a second layer (4) of washable material, constrained to a second surface (32) of said first layer (3) opposite said first surface (31); a third layer (5) of porous and washable material, applied on the external surface of said second layer (4), that is, on the opposite side of said first layer (3); and wherein said third layer (5) is wholly or partly soaked with at least one biocidal substance.

2. Protective mask (10) according to claim 1, characterized in that it comprises a last layer (6) applied at least on the surface of said third layer (5) facing outwards, that is, on the opposite side from the user's face, and where said last layer (6) comprises said biocidal substance.

3. Protective mask (10) according to claim 1, characterized in that said biocidal substance is made up of a stabilized hydroalcoholic gel.

4. Protective mask (10) according to claim 2, characterized in that said last layer (6) is directly applied on said third layer (5) by glazing or spraying or spreading or molding said stabilized hydroalcoholic gel.

5. Protective mask (10) according to claim 1, characterized in that said first layer (3) is wholly or partly made of cotton fabric.

6. Protective mask (10) according to claim 1, characterized in that said first layer (3) has a thickness between 0.5 and 0.6 mm.

7. Protective mask (10) according to claim 1, characterized in that said second layer (4) is wholly or partly made of non-woven fabric or other similar material currently used for air filters.

8. Protective mask (10) according to claim 1, characterized in that said second layer (4) has a thickness between 0.6 and 0.8 mm.

9. Protective mask (10) according to claim 1, characterized in that said third layer has a thickness between 0.1 and 0.3 mm.

10. Protective mask (10) according to claim 1, characterized in that said last layer has a thickness between 0.1 and 0.2 mm.

11. Method for making a protective mask (10) according to one or more of the preceding claims, characterized in that it comprises the following steps: assembly of said first, second and third layers (3, 4, 5); - application of said last layer (6) on said third layer (5), so that said biocidal substance soaks at least part of said third layer (5) and/or covers at least part of its external surface.

12. Method for washing and restoring the barrier function of said mask (10) according to any one of claims 1 to 8, characterized in that it comprises the following steps:

- washing of said mask (10) with at least one sanitizing agent;

- application of said last layer (6) on said third layer (5).