METHOD OF PRODUCTION OF A FILTERING MATERIAL AND A FILTERING FIBROUS MATERIAL Russian patent published in 2006 - IPC B01D39/16 B32B5/26 D04H1/56 

FIELD: methods of production of filtering materials.

SUBSTANCE: the invention is pertaining to the methods of production of filtering materials, in particular, to the method of production of the filtering fibrous materials, which may be used in a means of individual protection. The filtering fibrous material is produced by an electrostatic formation of a non-woven fibrous material from a working polymeric fiber-forming solution with dynamic viscosity of 1-30P, electrical conduction of 10^-4-10^-7 ohm^-1 cm^-1 in an electrostatic field at a potential difference from 10 up to 150 kV. The solution contains in the capacity of the polymer from 8.9 up to 24.6 mass % of styrene copolymer with 5.2-30.4 mass of acrylonitrile or triple styrene copolymer with 5.2-30.4 mass of acrylonitrile and 3.7-42.1 mass % of methyl methacrylate. As a dissolvent they use ethyl acetate, or butyl acetate either their mixture. The solution in addition contains high-molecular polymethyl methacrylate, a distilled water, the lowest alcohol taken from the group ethyl alcohol, methyl alcohol or isopropyl alcohol, at the following contents of ingredients of the polymeric fiber-forming solution, in mass %: polymeric compound - 8.9-24.6; high-molecular polymethyl methacrylate - 0.011-0.02; distilled water - 0.01-0.1; the lowest alcohol - 17-28; dissolvent - the rest. The efflux of the working polymeric fiber-forming solution is exercised at the volumetric speed of 0.1 up to 6 cm³ /minute. Feeding of the working polymeric fiber-forming solution is conducted from the space interval of 12-42 cm beginning from the point of its coming out from the batching device up to the settling surface. The produced filtering fibrous material contains a technological and a working layers made out of the polymeric fibrous material produced by the above described method. The technological layer material has the surface density of 1-3 g/m² and is made out of fibers of 3-5 microns diameter. The working layer material is made out of fibers of 1.5-3 microns diameter. The double-layer material has the surface density of 32-38 g/m², the standard resistance of 0.8-1.2 mm of the water column and the skip coefficient of no less than 95 %. The invention ensures an improved quality of the filtering material due to an increase of efficiency of penetration of fragments with a diameter of 0.3 microns at the standard resistance of 1.0 mm of the water column.

EFFECT: the invention ensures an improved quality of the filtering material, an increased efficiency of penetration of fragments with a diameter of parts of microns at the standard resistance of 1 mm of the water column.

4 cl, 2 ex