WO2021224773A1

WO2021224773A1 - Face mask for filtering microbial loads and suspended particles

Info

Publication number: WO2021224773A1
Application number: PCT/IB2021/053706
Authority: WO
Inventors: Maurizio FASOLO; Valentino Scalco
Original assignee: Be-Brand S.R.L.; Ambra Elettronica S.R.L.
Priority date: 2020-05-05
Filing date: 2021-05-04
Publication date: 2021-11-11
Also published as: IT202000009958A1

Abstract

Face mask (1) for filtering microbial loads and suspended particles comprising a thinned support (2), which is provided with an external face (3) and with an internal face (4) and is intended to cover a part of the face of a user, and a filtering device (5) fixed to the thinned support (2). The filtering device (5) comprises: a support body (6), which delimits an air passage channel (7) which is extended along an extension axis (X) between a first opening (8) thereof lying on the internal face (3) and at least one second opening (9) lying on the external face (4); a filter (10) placed transverse to the extension axis (X) in order to intercept the air which flows in the air passage channel (7); an ultraviolet light source (11) housed in the air passage channel (7) and directed towards the filter (10); and power supply means (12) electrically connected to the ultraviolet light source (11) in order to power supply it. The filtering device (5) also comprises heating means (13) mechanically fixed to the support body (10), electrically connected to the power supply means (12) and associated with the filter (10) in order to transmit heat thereto.

Description

FACE MASK FOR FILTERING MICROBIAL LOADS AND SUSPENDED PARTICLES

DESCRIPTION Field of application

The present invention regards a face mask for filtering microbial loads and suspended particles, according to the preamble of the independent claim 1.

The present face mask has particular application in the field of production of individual protection devices and of surgical medical aids.

The present face mask is advantageously intended to be worn by a user to cover his/her own airways, i.e. nose and mouth, in order to prevent the user himself/herself from inhaling, during the inspiration respiratory phase, microbial loads, such as for example viruses, bacteria or fungi, and suspended particles, such as for example dusts that form the atmospheric particulate.

Alternatively or additionally, the present filtering mask prevents the user, if for example he/she is suffering from a contagious pathology of respiratory type, from infecting other people with whom the user can come into contact, retaining microbial loads emitted by the user during the exhaling respiratory phase.

State of the art

In the field of production of individual protection devices and surgical medical aids, face masks have for some time been known that are intended to be worn by a user in order to cover his/her own airways, in order to prevent the user from inhaling microbial loads and suspended particles and/or, in the event in which for example the user himself/herself is suffering from a respiratory pathology, the emission of microbial loads which could infect other people with whom the user possibly comes into contact.

Known from the Australian patent AU 2020100228 is a face mask, which comprises a thinned support, provided with an external face and with an internal face and intended to cover at least one part of the face of a user at the nose and mouth, and a filtering device fixed to the thinned support.

The filtering device comprises a support body, which delimits two air passage channels placed to traverse the thinned support and each extended along an extension axis thereof between a first opening lying on the internal face of the thinned support and a second opening lying on the external face of the thinned support.

Within each air passage channel, a filter is positioned which is placed transverse to the extension axis of the corresponding air passage channel in order to intercept the air which flows at its interior.

In particular, a filter is arranged in order to retain the microbial loads carried by the air inhaled by the user, in order to prevent them from coming into contact with the airways of the user himself/herself, and the other filter is arranged in order to retain the microbial loads carried by the air exhaled by the user in order to prevent them from being spread into the environment and infecting people who may possibly come into contact with the user himself/herself who wears the face mask.

The air passage channels allow the user to breathe while he/she wears the face mask, since they are traversed by the air inhaled by the user and, in opposite sense, by the air exhaled by the user, while the filters placed to intercept the aforesaid channels retain the microbial loads and the suspended particles transported by the air. In particular, during the inhalation the air that passes into the passage channel traverses the filter which blocks, on its surface, the pathogenic agents that thus remain outside the airways.

The filters of known type are generally divided into three categories, i.e. PI, P2 and P3, based on the size of the suspended particles and of the microbial loads that they are capable of retaining. The filters of category PI and P2 are only capable of retaining suspended particles, formed in particular by dusts, and are easily traversed by microbial loads having smaller dimensions. The fdters of category P3 are instead capable of also retaining the microbial loads, since they can retain foreign bodies with dimensions even smaller than a micrometer. The fdters of category P3, nevertheless, even after a few hours of use, lose their capacity to retain the microbial loads and therefore they must be disposed of as waste.

In addition, the filtering device of the face mask also comprises two ultraviolet light sources mechanically fixed to the support body, each housed in the corresponding air passage channel, directed towards the extension axis of the corresponding air passage channel and arranged for sterilizing the air that traverses the channel itself.

Nevertheless, the filtering mask of known type described briefly up to now has in practice demonstrated that it does not lack drawbacks.

The main drawback lies in the fact that the filter becomes a point of accumulation of the particles to be filtered and it is therefore necessary to provide for a regular cleaning thereof or substitution so that the protective effectiveness of the mask is not compromised over time.

A further drawback is due to the fact that the ultraviolet light sources must remain permanently on during the use of the mask in order to sterilize the air, therefore involving the use of bulky batteries in order to electrically power supply the ultraviolet light source.

Presentation of the invention

In this situation, the problem underlying the present invention is therefore that of eliminating the abovementioned prior art, by providing a face mask, which is capable of operating in an efficient manner for long periods without the user having to clean or substitute the filter.

A further object of the present invention is to provide a face mask, which allows minimizing the impact of disposal and waste of materials.

A further object of the present invention is to provide a face mask, which is capable of operating with a limited energy consumption by the electrical components, in particular avoiding the use of batteries with bulky dimensions.

A further object of the present invention is to provide a face mask, which is easy and simple for a user to put on.

A further object of the present invention is to provide a face mask, which is operatively efficient and entirely reliable.

Brief description of the drawings

The technical characteristics of the invention, according to the aforesaid objects, are clearly visible from the contents of the below-reported claims and the advantages thereof will be more evident in the following detailed description, made with reference to the enclosed drawings, which represent a merely exemplifying and non-limiting embodiment of the invention in which:

- figure 1 shows a front view of the face mask according to the present invention; figure 2 shows a side sectional view of the face mask of figure 1, made along the trace II- II.

Detailed description of a preferred embodiment With reference to the enclosed figures, reference number 1 overall indicates a face mask for filtering microbial loads and suspended particles according to the present invention.

The present face mask 1 has particular application in the industrial field of production of surgical medical aids and individual protection devices.

The present face mask 1 is in fact intended to be worn by a user to cover his/her own airways, i.e. nose and mouth, so as to filter the air that is sucked in and/or out by such user, retaining microbial loads, such as for example viruses, bacteria, fungi or other pathogenic agents, and suspended particles.

The face mask 1 according to the invention comprises a thinned support 2, which is provided with an external face 3 and with an internal face 4 and is intended to cover at least one part of the face of a user, in particular at the airways of the nose and of the mouth.

The face mask 1 also comprises at least one filtering device 5 fixed to the thinned support 2 and arranged for selectively retaining the pathogenic or pollutant agents present in the air. More in detail, the filtering device 5 comprises a support body 6, which delimits an air passage channel 7 placed to traverse the thinned support 2 and extended along an extension axis X between at least one first opening 8 thereof lying on the internal face 4 of the thinned support 2 and at least one second opening 9 lying on the external face 3 of the thinned support 2

In particular, the thinned support 2 is provided with a through hole in which is placed the support body 6 of the filtering device 5, possibly extended projectingly with respect to the external face 3 and/or to the internal face 4 of the thinned support 2.

Suitably, the support body 6 of the filtering device 5 is fixed to the thinned support 2, in particular along the edge of the through hole of the latter, by means of attachment means of per se known type, such as gluing, hot melt, stapling, etc.

The filtering device 5 also comprises at least one filter 10 mechanically connected to the support body 6 and placed transverse to the extension axis X of the air passage channel 7 in order to intercept the air which flows in the air passage channel 7.

The filtering device 5 also comprises at least one ultraviolet light source 11 mechanically fixed to the support body 10, housed in the air passage channel 7 and directed towards the filter 10 in order to emit, on the latter, UV electromagnetic radiations (in particular UVC). Preferably, the ultraviolet light source 11 is arranged for emitting an ultraviolet light beam having wavelength comprised between 100 and 300 nanometers.

The filtering device 5 is provided with power supply means 12 electrically connected to the ultraviolet light source 11 in order to power supply the latter with the electrical energy necessary for the operation thereof. According to the idea underlying the present invention, the fdtering device 5 also comprises heating means 13 mechanically fixed to the support body 10, electrically connected to the power supply means 12 and associated with the filter 10 in order to transmit heat thereto. During use, when the face mask 1 is worn by a user, the air that is inhaled and exhaled is mainly forced to traverse the air passage channel 7 in order to be intercepted by the filter 10, which is arranged in order to retain the pathogenic or pollutant agents which are carried by the air itself. In particular, the filter 10 prevents microbial loads from coming from the outside environment and transported by the air inhaled by the user to come into direct contact with the airways of the user himself/herself, or, in the event in which for example the user suffers from a contagious pathology, prevents the microbial loads expelled through the air exhaled from the user from being spread into the outside environment and infecting other people.

During the use of the face mask 1, the filter 10 continues to accumulate microbial loads. In order to prevent such microbial loads from negatively affecting the capacity of the filter 10 to filter the air, the latter is subjected to a sterilization executed by means of a synergistic action carried out by the heating means 13 and from the ultraviolet light source 11.

The heating means 13 are in fact arranged in order to transmit heat to the filter 10 in order to increase the temperature thereof and the ultraviolet light source 11 is arranged for emitting a UV ray beam (in particular UVC) which hits the aforesaid filter 10 in order to deactivate the microbial loads present thereon. In particular, the heat transmitted by the heating means 13 to the filter 10 renders the microbial loads particularly vulnerable to the UV rays emitted by the ultraviolet light sources 11, such that such UV rays can effectively and quickly deactivate the microbial loads, sterilizing the filter 10.

Following the aforesaid sterilization, the capacity of the filter 10 to retain further microbial loads is at least partially restored and the user can then use the filtering mask 1 without having to frequently substitute the filter 10. The heating means 13 are preferably arranged for transferring heat to the filter 10, increasing the temperature thereof in an interval comprised between 60 and 90°C. In particular, such temperature interval ensures a suitable action on the microbial loads, without requiring high consumption of energy by the heating means 13 and without creating disturbances for the user.

In order to allow the inhaled or exhaled air to pass only through the air passage channel 7 and thus prevent it from passing through possible slits formed between the face of the user and the internal face 4 of the thinned support 2 without it being intercepted by the filter 10, the thinned support 2 itself is preferably provided with a seal placed to delimit the internal face 4 and intended to adhere to the face of the user.

Optionally, the face mask 1 comprises a protective covering (not illustrated in the enclosed figures), which is removably placed on the internal face 4 of the thinned support 2, in particular by means of suitable coupling means, for example comprising Velcro strips. Such protective covering is attained for example with a sheet of breathable material that allows the passage of the air and is placed to protect the thinned support 2 and the filtering device 5 from contact with the skin of the user.

Preferably, the thinned support 2 is provided with two lateral ends 22, at which attachment means 23 are mechanically connected in order to maintain the thinned support 2 itself on the face of the user.

The attachment means 23, in an entirely conventional manner, comprise two elastic laces 24, which are each extended between a first end 25 and a second end 26 and are fixed to one of the two lateral ends 22 of the thinned support 2 in order to define a retention portion 27 shaped substantially with “U” form and intended to enclose the rear portion of one of the two ears of the user. Otherwise, the attachment means 23 comprise a band extended between a first end fixed to one of the two lateral ends 22 of the thinned support 2 and an opposite second end fixed to the other of the two lateral ends 22 in order to define a retention portion substantially shaped with “U” form and intended to enclose the nape of the user.

Preferably, the thinned support 2 of the face mask 1 comprises a sheet-like body, advantageously made of a flexible material, such that it can be easily adapted to the shape of the face of the user and hence make the present face mask 1 comfortable to wear. Otherwise, the thinned support 2 can also be made of a rigid or semi-rigid material, as a function of the specific use destinations.

Suitably, the thinned support 2 has concave form (pre-molded or via deformation on the face of the user) on its internal surface 4, in order to ensure an optimal wearability on the face of the user.

Advantageously, the filtering device 5 comprises a logic control unit 14 fixed to the support body 6, electrically connected to the power supply means 13 and susceptible of activating the ultraviolet light source 11 and/or the heating means 13 according to programmed operating modes.

The support body 6 of the filtering device 5 is advantageously provided with a seat 15 in which the filter 10 is removably housed.

More in detail, the filter 10 is removable with respect to the seat 15 of the support body 6 so as to be able to remove it, dispose of it as waste and substitute it with a new filter 10. Such substitution can be due to the fact that, notwithstanding the action of sterilization of the heating means 13 and of the ultraviolet light source 11, the filter 10 is also susceptible of retaining suspended particles (such as for example dusts that form the atmospheric particulate) which, after various uses of the face mask 1 by the user, obstruct the filter 10.

The filter 10 advantageously comprises a rigid frame 16 and a flexible separator 17 supported perimetrically by the rigid frame 16. More in detail, the rigid frame 16 is housable within the seat 15 with the flexible separator 17 placed transverse to the extension axis X of the air passage channel 7.

In particular, the rigid frame 16 facilitates the removal or the insertion of the filter 10 in the seat 15, since it allows the user to firmly grasp the filter 10 itself and handle it. Advantageously, the heating means 13 are mechanically fixed to the support body 6, in a position opposite the filter 10.

Preferably, the heating means 13 comprise at least one electrical resistor intended to be traversed by electric current, which is supplied by the aforesaid power supply means 12, in order to generate heat by means of Joule effect and transfer it to the filter 10.

In particular, the electrical resistor comprises one or more wires made of electrically conductive material, which are shaped substantially as a “coil” or they are placed to form a grid, so as to not obstruct the traversing of the air within the air passage channel 7. Optionally, the electrical resistor can be made by means of an electrically conductive fabric.

In accordance with the preferred embodiment illustrated in the enclosed figures, the heating means 13 have substantially planar extension on a lying plane a placed substantially perpendicular to the extension axis X of the air passage channel 7 and parallel to the flexible separator 17 of the filter 10, which is in turn placed substantially perpendicular to the extension axis X. In this manner, the space occupied by the heating means 13 and by the filter 10 along the extension axis X itself is particularly reduced and consequently the support body 6 can be provided, between the first and the second opening 8, 9 of the air passage channel 7, with a limited thickness.

Suitably, the heating means 13 are arranged in order to transmit the heat to the filter 10 via irradiation and/or via conduction, in particular able to be placed in contact or not in contact with the filter 10 itself.

In accordance with an embodiment variant not illustrated in the enclosed figures, the heating means 13 comprise LED sources of infrared rays directed towards the filter 10, and placed on the same side or on the opposite side of the latter with respect to the ultraviolet light source 11

Advantageously, the support body 6 of the fdtering device 5 comprises support means 18 projecting within the air passage channel 7 and carrying fixed thereto the ultraviolet light source 11 in a position opposite the filter 10.

In addition, the support means 18 advantageously delimit, with the filter 10, a sterilization chamber 19.

Preferably, the support means 18 comprise at least one support arm 28 extended along a longitudinal axis Y, which is substantially perpendicular to the extension axis X of the air passage channel 7, between a first end 29 connected to the support body 6 and a second end 30 placed across from the filter 10, in particular at the extension axis X itself.

The ultraviolet light source 11, in a position opposite the filter 10, is preferably fixed to the support arm 28 at the second end 30 thereof. In this manner, the ultraviolet light source 11 is positioned substantially centrally with respect to the air passage channel 7, so as to completely illuminate the filter 10 in a substantially uniform manner.

In accordance with the preferred embodiment illustrated in the enclosed figures, the filter 10 is interposed between the heating means 13 and the ultraviolet light source 11, in a manner such that the ultraviolet light source 11 can completely illuminate one face of the flexible separator 17 without the heating means 13 even partially covering it.

Suitably, the flexible separator 17 of the fdter 10 is provided with a first face 31, directed towards the first opening 8 of the air passage channel 7 (placed on the internal face 4 of the thinned support 2), and with an opposite second face 32, directed towards the second opening 9 of the air passage channel 7 (placed on the external face 3 of the thinned support 2). Advantageously, the ultraviolet light source 11 faces one of the two faces 31, 32 of the flexible separator 17, for example, with reference to the example of figure 2, the second face 32, with the heating means 13 preferably placed on the first face 31.

Advantageously, the ultraviolet light source 11 is provided with an emission axis oriented towards the filter 10, in a manner such that the filter 10 (and in particular one of the faces 31, 32 of the flexible separator 17) is intercepted by the emission axis itself, in substance ensuring that part of the UV radiation emitted by the ultraviolet light source 11 hits the filter 10 itself. For example, the emission axis of the light source 11 is placed aligned with the extension axis X of the air passage channel.

Preferably, the ultraviolet light source 11 comprises one or more LEDs electrically connected to the power supply means 12.

In accordance with the example illustrated in figure 2, the LED of the ultraviolet light source 11 is frontally directed towards the filter 10, in a manner such that the optical axis of the LED defines the emission axis of the ultraviolet light source 11 and the UY radiation emitted by the LED directly reaches the filter 10 itself.

In accordance with a different embodiment not illustrated in the enclosed figures, the ultraviolet light source 11 is provided with an optical transmission system (e.g. a system of reflection mirrors or an optical guide), which is arranged in order to transmit the UV radiation from the LED towards the filter 10 according to a predetermined optical path which defines, at its end, the emission axis of the ultraviolet light source 11. In such case, for example, the LED can be placed laterally with respect to the filter 10 (also outside the air passage channel 7) with its optical axis which is not directed towards the filter 10 and is intercepted by the optical transmission system in order to direct the UV radiation towards the filter 10 itself. Conventionally, the filter 10 can be arranged in order to function in a first operating sense for filtering the air inhaled by the user (in order to protect the user), or in a second operating sense for filtering the air exhaled by the user (in order to protect the people around the user). Suitably, the filter 10 is arranged in order to be positioned in the air passage channel, in a selectable manner, in one of the two aforesaid operating senses, as a function of the particular situations of use of the face mask 1.

Of course, without departing from the protective object of the present patent, the filtering device 5 (and in particular the filter 10) can be arranged for operating, simultaneously, in both operating senses. For example, the filtering device 5 can be provided with two air passage channels, each intercepted by the corresponding filter 10, of which a filter 10 is placed in the first operating sense and the other filter 10 is arranged in the second operating sense. Advantageously, the power supply means 12 comprise a battery 20 mounted on the support body 6 of the filtering device 5.

In this manner, it is possible to power supply the heating means 13 and the ultraviolet light source 11 also during use by the user of the present face mask. The user can therefore wear the face mask 1 for several consecutive hours without the filter 10 losing its capacity to retain the microbial loads, the heating means 13 and the ultraviolet light source 11 being power supplied by the battery 20, which is directly integrated in the filtering device 5.

Preferably, the power supply means 12 comprise a switch placed on the containment body 6 in order to enable and disable the electrical power supply provided by the battery 20 to the heating means 13 and to the ultraviolet light source 11, and advantageously to the logic control unit 14.

In accordance with a different embodiment, the power supply means 12 comprise a battery positionable in a position distal from the thinned support 2 of the face mask 1 and electrical connection means for electrically connecting the battery to the ultraviolet light source 11 and to the heating means 13. For example, the battery is housed in an auxiliary containment body and the electrical connection means comprise a power supply cable placed to join the aforesaid containment body and the filtering device 5. In this manner, the battery employed in order to power supply the heating means 13 and the ultraviolet light source 11 can have size and weight greater than the case in which it is directly integrated in the filtering device 5 and, therefore, also greater duration.

Advantageously, the logic control unit 14 comprises an electronic circuit board 21 fixed to the support body 6 and connected to the battery 20.

Advantageously, the logic control unit 14 is programmed in order to power supply the ultraviolet light source 11 and the heating means 13 in a discontinuous manner, in particular in a cyclic manner.

In particular, the logic control unit 14 is programmed for alternatively operating, preferably in a cyclic manner, between:

- a first operating state, in which the logic control unit 14 enables the power supply means 12 to power supply the ultraviolet light source 11 and/or the heating means 13;

- a second operating state, in which the logic control unit 14 disables the power supply of the ultraviolet light source 11 and of the heating means 13.

Advantageously, the actuation of the ultraviolet light source 11 and/or of the heating means 13 is driven by the logic control unit 14 at iteration intervals that can vary substantially between 1 minute and multiple tens of minutes (30 minutes or more), in particular as a function of the operating and energy specifications to be met.

Suitably, the logic control unit 14 is arranged for operating in the first operating state for a specific power supply interval (with duration for example from several fractions of seconds to several tens of seconds), and subsequently for operating in the second operating state for a suspension interval (with duration for example from several tens of seconds to multiple tens of minutes), in a manner such that, preferably, the sum of the power supply interval of the suspension interval is equal to the aforesaid iteration interval.

Advantageously, the electronic control unit 14 is arranged for enabling the ultraviolet light source 11 to irradiate the fdter 10, providing an overall quantity of energy per cycle comprised substantially from 20 mJ to 200 mJ.

Advantageously, the logic control unit 14 is programmed in order to sequentially power supply heating means 13 first and then the ultraviolet light source 11.

In this manner, when the ultraviolet light source 11 is power supplied for sterilizing the filter 10 against the microbial loads retained thereby, the heating means 13 have already transferred heat to the filter 10 itself in order to increase the temperature thereof and thus render the action of the ultraviolet light source 11 more efficient.

In particular, with the expression “sequentially” it must be intended hereinbelow that the logic control unit 14 can power supply the ultraviolet light source 11 both with the heating means 13 still power-supplied, and with the heating means 13 that have just been disabled. Advantageously, the power supply of the ultraviolet light source 11 following the disabling heating means 13 allows distributing the consumption of electrical energy by the filtering device 5 over a wider time interval and thus prevent electrical energy consumption peaks which more greatly tend to reduce the duration of the battery 20.

For example, the logic control unit, in the first operating state, is programmed for enabling the power supply of the heating means 13 for a first power supply sub-interval and for enabling the power supply of the ultraviolet light source 11 for a second power supply sub-interval.

In particular, the first and the second power supply sub-intervals are completely distinct from each other in order to allow the heating means 13 to function only when the ultraviolet light source 11 is turned off, and vice versa. Otherwise, the first and the second power supply sub interval can be partially superimposed, in a manner such to simultaneously operate the heating means 13 and the ultraviolet light source 11 for a specific time interval.

Of course, without departing from the protective scope of the present patent, the logic control unit 14 is programmable for enabling the heating means 13 and the ultraviolet light source 11 to operate simultaneously for the entire duration of the power supply interval. In operation, when the user wears the face mask 1 and turns on the filtering device 5, the logic control unit 14 power supplies, in particular according to the operating modes discussed above, the ultraviolet light source 11 and the heating means 13 in order to execute, in particular cyclically, the sterilization of the filter 10, so as to prevent the filter 10 from losing its capacity to retain the microbial loads.

Preferably, as discussed, the logic control unit 14 is programmed in order to power supply the heating means 13 in a first pre-established power supply sub-interval and in order to power supply the ultraviolet light source 11 for a second pre-established time sub-interval.

In particular, the first time sub-interval is calibrated as a function of a standard use temperature of the face mask 1, such that the heating means 13, at the end of the aforesaid first power supply sub-interval, has brought the filter 10 to a pre-established target temperature (advantageously comprised between 60°C and 90°C), and the second power supply sub-interval is calibrated in order to allow the ultraviolet light source 11 to sterilize the filter 10 in an optimal manner at the target temperature.

Nevertheless, in the event in which the sterilization of the filter 10 is executed at an ambient temperature which is different from the standard use temperature of the face mask 1, at the end of the first time interval, the heating means 13 bring the filter 10 to a temperature which is in turn different from the target temperature, thus limiting the effectiveness of the ultraviolet light source 11 in the sterilization of the filter 10.

In accordance with an optional embodiment, the filtering device 5 comprises a temperature sensor 33, which is functionally associated with the filter 10 in order to detect temperature measurements associated with the latter, and is electrically connected to the electronic control unit 14 in order to send, to the latter, measurement signals indicative of the temperature of the filter 10 itself. For example, the temperature sensor 33 is mechanically fixed to the support body 6, is housed in the air passage channel 7, preferably in the sterilization chamber 19 in proximity to the filter 10, is electrically connected to the electronic control unit 14 and is arranged for measuring the temperature within the air passage channel 7 and sending corresponding measurement signals to the electronic control unit 14. The latter is programmed in order to power supply the heating means 13 as a function of the measurement signals received by the temperature sensor 33, in particular in order to disable the heating means 13 upon reaching the pre-established target temperature. This embodiment, in particular, allows ensuring to bring the filter 10 to the target temperature even in the event in which the face mask 1 is employed at different temperatures, quite different from the ambient temperature. The finding thus conceived therefore attains the pre-established objects.

Claims

1. Face mask (1) for filtering microbial loads and suspended particles, which comprises:

- a thinned support (2) provided with an external face (3) and with an internal face (4), intended to cover at least one part of the face of a user, in particular at the airways of the nose and of the mouth;

- at least one filtering device (5) fixed to the thinned support (2) and comprising:

- a support body (6), which delimits an air passage channel (7) placed to traverse said thinned support (2) and is extended along an extension axis (X) between at least one first opening (8) thereof lying on the internal face (4) of said thinned support (2) and at least one second opening (9) lying on the external face (3) of said thinned support (2);

- at least one filter (10) mechanically connected to said support body (6), which is placed transverse to the extension axis (X) of said air passage channel (7) in order to intercept the air which flows in said air passage channel (7);

- at least one ultraviolet light source (11) mechanically fixed to said support body (10), housed in said air passage channel (7) and directed towards said filter (10);

- power supply means (12) electrically connected to said ultraviolet light source (11) in order to power supply said ultraviolet light source (11); said face mask (1) being characterized in that said filtering device (5) also comprises heating means (13) mechanically fixed to said support body (10), electrically connected to said power supply means (12) and associated with said filter (10) in order to transmit heat thereto.

2. Face mask (1) for filtering microbial loads and suspended particles, according to claim 1, characterized in that said filtering device (5) comprises a logic control unit (14) fixed to said support body (6), electrically connected to said power supply means (13) and susceptible of activating said ultraviolet light source (11) and/or said heating means (13) according to programmed operating modes.

3. Face mask (1) for fdtering microbial loads and suspended particles, according to claim 1 or 2, characterized in that the support body (6) of said fdtering device (5) is provided with a seat (15) in which said fdter (10) is removably housed.

4. Face mask (1) for fdtering microbial loads and suspended particles, according to claim 3, characterized in that said fdter (10) comprises a rigid frame (16) and a flexible separator (17) supported perimetrically by said rigid frame (16); said rigid frame (16) being able to be housed within said seat (15) with said flexible separator (17) placed transverse to the extension axis (X) of said air passage channel (7).

5. Face mask (1) for fdtering microbial loads and suspended particles, according to any one of the preceding claims, characterized in that heating means (13) are mechanically fixed to said support body (6), in a position opposite said fdter (10).

6. Face mask (1) for fdtering microbial loads and suspended particles, according to any one of the preceding claims, characterized in that the support body (6) of said fdtering device (5) comprises support means (18) projecting within said air passage channel (7) and carrying fixed thereto said ultraviolet light source (11) in a position opposite said filter (10).

7. Face mask (1) for fdtering microbial loads and suspended particles, according to claim 6, characterized in that said support means (18) delimit, with said filter (10), a sterilization chamber (19).

8. Face mask (1) for fdtering microbial loads and suspended particles, according to any one of the preceding claims, characterized in that said power supply means (12) comprise a battery

(20) mounted on the support body (6) of said fdtering device (5).

9. Face mask (1) for filtering microbial loads and suspended particles, according to claims 2 and 8, characterized in that said logic control unit (14) comprises an electronic circuit board

(21) fixed to said support body (6) and connected to said battery (20). 10. Face mask (1) for filtering microbial loads and suspended particles, according to any one of the preceding claims, characterized in that said power supply means (12) comprise a battery positionable in a position distal from the thinned support (2) of said face mask (1) and electrical connection means for electrically connecting said battery to said ultraviolet light source (11) and to said heating means (13).

11. Face mask (1) for filtering microbial loads and suspended particles, according to claim 2, characterized in that said logic control unit (14) is programmed for power supplying said ultraviolet light source (11) and said heating means (13) in a discontinuous manner.

12. Face mask (1) for filtering microbial loads and suspended particles, according to claim 2, characterized in that said logic control unit (14) is programmed for sequentially power supplying said heating means (13) first and then said ultraviolet light source (11).

13. Face mask (1) for filtering microbial loads and suspended particles, according to claim 2, characterized in that said filtering device (5) comprises at least one temperature sensor (33), which is functionally associated with said filter (10), is electrically connected to said logic control unit (14), and is arranged in order to detect temperature measurements associated with said filter (10) and send corresponding measurement signals to said logic control unit (14), which is programmed for power supplying said heating means (13) as a function of said measurement signals.