FILTERING MATERIAL FOR PROTECTION AGAINST AIR SUSPENDED PARTICLES Russian patent published in 2020 - IPC B01D39/16 A62B7/10 A62B23/02 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of filtration materials, preferably used for cleaning air from aerosol particles and which can be used as main material and/or in a set of protective materials for making light filtering half-masks, corrugated filters and air-permeable screens for protection against dust particles, aerosol combustion products, microorganisms and pollen of plants. Filter material for protection against air suspended suspensions comprises nanomembrane formed by means of an adhesive layer on the frame layer, formed by electroforming from a spinning solution, and applied on the opposite side of nanomembrane outer layer. Nanomembrane layer is formed from a spinning solution containing a copolymer of vinylidene fluoride and tetrafluoroethylene, polyacrylonitrile and dimethylformamide with concentration of copolymer in 6.0–7.5 wt% solution, at concentration of polyacrylonitrile in solution 6.0–7.5 wt % and dimethylformamide – the rest. Adhesive layer is an aqueous dispersion of polyacrylate particles. Frame layer is made of woven fabric consisting of polypropylene, polyester or kapron threads. Nanomembrane has a surface density of not more than 0.5 g/m², fiber diameter is 50–500 nm.

EFFECT: creation of effective filtering material with protective properties, resistant to moisture and draining of electric charge, obtaining filtering material having aerodynamic resistance of not more than 25 Pa at air flow rate of 8_34 cm/s, filtration efficiency of not less than 95 % with respect to aerosol particles with size of 0_1–0_4 mcm at air flow rate of 5 cm/s.

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