The present invention relates to the field of face mask and respirators for personal protection against pollutants, pathogens, and viral diseases
BACKGROUND OF INVENTION
Pandemic cause by COVID -19 has created a great concern over personal health and safety for human beings. COVID -19 spreads primarily via droplets containing the virus. The droplets may either transmit through air due to sneezing of an infected person in vicinity or due to surface contaminated by the infected droplets. It is determined that the COVID-19 virus remains active on different surfaces ranging from few hours to many days, before getting inactive.
The main reason for acquiring the infection is by entry of the virus from nose and mouth, at the same time the main reason of spread is also from expulsions from nose and mouth. To prevent the contamination or spread of disease, face mask or respirators have become the best method of prevention apart from frequent disinfection of hands.
Face masks, in case of medical professionals help in prevent spreading of virus during treatment of infected patient in proximity. Such face mask needs to be of better quality in terms of filtration efficiency and other functional properties and are governed by various compliance agencies like NIOSH, FDA etc.
Face mask used by general population does not require stringent compliance as the purpose in this case is to prevent spread of infection droplets in surrounding when a person talks, sneezes etc.
There are a variety of face mask available in market or even made at home. Apart from the compliant face mask there is a lot of variation in non-compliant face mask.

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Face mask is an important PPE and even though non-compliant to any standard need to be made with proper care so that it does not harm the user during use.
One of the concerns in face mask is a concern of infection or pathogen generation due to prolonged use or multiple use. This happens due to the humid and conducive environment created on the inner side of mask as the user breaths out. This also results in bad odour after certain usage of face mask. This results in a poor breathing condition and a tendency to discontinue or intermittent use of mask which can be harmful as it may result in infection spread.
One of the approaches to overcome this problem is to use an anti-microbial agent in face mask. This inhibits the growth of micro-organism and prevents generation of odour.
Various agents have been used as an anti-microbial agent to achieve desired result like use of Nano-silver (CN101946990A), various metals (US20110232653A1), anti-microbial property of bamboo (WO2016099417A1). In case of metal and metal salts the anti-microbial activity depends on the release of metal ions, which can enter user's body from mouth and nose. This can have harmful effect over a period of usage. An organic anti-microbial occurring in nature is a good alternative to overcome some of the mentioned issue. The invention proposes use of curcumin as an active anti-microbial agent. Curcumin is a naturally occurring curcuminoid which is main compositional element in turmeric. In India turmeric had been used since ages in food preparation, as a medicinal component and as a preservative in pickles. It has a proven record of being healthy to a human body even if ingested. A face mask with one of more of its layers treated with curcumin is proposed along with other naturally occurring ingredients like Aloe Vera, Peppermint, Lemon Oil, Eucalyptus Oil to impart a multiple wash durable anti-microbial activity, conditioning, moisturizing effect in face mask.

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SUMMARY OF INVENTION
A face mask which consist of multiple layers of fabric, of which one or more layers is having antimicrobial property. The antimicrobial property achieved herein is by treating one or all of the layer of face mask with Curcumin, Aloe Vera, Peppermint, Lemon Oil, Eucalyptus Oil alone or in combination in various proportion. Along with the natural antimicrobial agents, one of the layers may contain use of commercial antimicrobial finish. These naturally occurring antimicrobial agent helps to keep the microbial growth in face mask under control. They also provide a freshness experience in breathing, giving user a pleasant wear experience. One of the layers in the face mask may include a charged melt blown filter media. An outer layer may include a fluid repellent finish. The layers of fabric in the mask may be made of nonwoven, knitted and woven structure. The mask can be single use or can be used multiple times by washing.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A system, of the present disclosure, will now be described with reference to accompanying drawing, in which:
Figure 1 illustrates a schematic view of face mask (100) with one or more layers of fabric treated with proposed anti-microbial finish, having an ear loop/headband attachment and an optional exhalation valve
Figure 2 illustrates another model of the anti-microbial face mask with expandable pleated construction and an optional nose clip
Figure 3 illustrates a cut section view of the mask layers used to assemble the mask. A maximum of 5 layers are possible.
LIST OF REFERENCE NUMERALS

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100 - Face Mask Design Concept 1
101-Exhalation Valve
102-Ear loop
103 - Face Mask Design Concept 2
104-Nose Clip
105 - Pleats
106-Head band
107 - Mask layer assembly
108-First/Outer Layer
109 -Second Layer
110-Third Layer
111-Fourth Layer
112-Fifth/Inner Layer
DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.

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The present disclosure envisages a face mask with an anti-microbial property. The anti-microbial property is imparted to the face mask (100,103) by treating one of more of the constituent layer of the mask (108 to 112) with Curcumin, Aloe Vera, Peppermint, Lemon Oil, Eucalyptus Oil alone or in combination in various proportion.
One of such the treatment system involved dipping a non-woven fabric made from cotton, cotton-polyester blend, cotton-polypropylene blend, which is cotton rich, in a mixture of aforementioned anti-microbial, anti-odour and moisturizing agent.
Similarly, a woven or a knit fabric with is made from cotton fibre or cotton fibre rich blend can be used for treatment of as one of the layers in the assembly of mask
The outer layer (108) is made of a fabric which can be non-woven, woven or knitted and is treated with a water repellent finish. This layer can be made from polypropylene or polyester fibres. This layer acts as a course filtration layer. The layer can weight from 30 - 50 gsm for a non-woven or 80 - 250 gsm for a woven or knitted fabric. The outer layer is dyed with a suitable yellow dye to give a visual appearance resembling that coming from treatment from turmeric.
The second layer (109) will be a filtration media, made up of melt blown or spun bond polypropylene material. This layer is not treated with an antimicrobial finish. This layer may not be present in a 2-layer mask system. This layer is made from polypropylene fibre with 25-35 GSM. In a 2-layer mask design this specific filtration layer is not present.
The third layer (110) again consist of either non-woven, woven or knit fabric, the third layer is treated with the proposed anti-microbial formulation and can also act a filtering layer. In a two-layer mask design, this layer will also act as the inner layer, the one in touch with the skin, thus providing a soothing skin care effect to the user.

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microbial finish. This layer is made of a 100% cotton to cotton rich bends with synthetic fibres weighing from 35-70 gsm in non-woven form and from 80-250 gsm in a woven of knitted form. If the layer is made from a cotton fibre or high melting point fibre then the mask assembly will be done using sewing process, else a ultrasonic welding may be used.
An optional fourth layer (111) is used as an additional layer treated with commercially available anti-microbial agent to enhance the overall anti-microbial performance of the mask. This layer may instead be treated with an aroma finish to provide a fresh breathing effect to user. This layer is made up of a cotton, cotton -polyester blended or polypropylene non-woven fabric weighing from 25 - 40 gsm.
The fifth or inner layer (112) is an enveloping layer providing support to the layers in between the outer (108) and inner (112) layer. This layer is treated with a hydrophilic finish to ensure sweat wieking off the skin. In another design this layer will be treated with moisturizing formulation based on Aloe Vera and other antioxidants to provide soothing effect to user's skin. This layer will be made of polypropylene spun bond nonwoven when used as a support and a cotton blended non-woven when acting as a soothing layer. The weight in both the cased will be between 35 to 45 gsm.
The anti-microbial, antioxidant, and moisturizing formulation is made by dissolving commercially available Curcumin and Aloe Vera in hot distilled water. The cotton rich substrate on which the treatment must be applied need to be bleached using hydrogen peroxide, this will enable better pickup and retention of agents.
A 1:100 ML ratio is used for padding bath and the pH is maintained at 5 by use of acetic acid. 5 gram per liter (gpl) of Curcumin can be used for application on the fabric. To increase the anti-microbial, antioxidative and moisturizing effect, 5 gpl Aloe Vera is also added to the padding bath. The bath temperature is maintained at

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90 degree Celsius. Fabric is maintained in the bath for 20 to 25 minutes for proper pickup and then rinsed in cold water.
The treated fabric is then dried in stenter or sun dried. An addon from 4 - 7 % is considered good in imparting the necessary anti-microbial property.

WE CLAIM
1. A face mask with multi-layer construction having anti-microbial property:
The anti-microbial effect is achieved by naturally occurring curcumin and aloe vera which are effective yet harmless to human ingestion.
2. A face mask claimed in claim 1 which is made from assembly of 2 to 5 layers
of fabric including a combination or non-woven, woven and knitted structure.
having an ear loop or head band to firmly hold the mask
having an exhalation valve
having a nose clip for good seal near nose
3. A face mask claimed in claim 2 having an outer layer treated with water repent finish and colored with a yellow pigment
4. A face mask claimed in claim 2 having a filter media layer with a particle filtration efficiency ranging from 90 to 99 %
5. A face mask claimed in claim 2 having a 100% cotton or cotton rich blended layer, treated with antimicrobial agent as per claim 1
6. A face mask claimed in claim 2 having and additional layer treated with commercial anti-microbial or fragrance finish
7. A face mask claimed in claim 2 with an inner layer having cotton rich composition treated with aloe vera for a soothing feel on the skin, optionally the inner layer made of hydrophobic fibers be treated with hydrophilic finish.

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8. A face mask claimed in claim 2 made up of two layers of woven or knitted fabric with inner layer treated with anti-microbial finish proposed in claim 1.