Filtering non-woven materials FNM
Filtering non-woven materials (FNM) are intended for thin clearing air and gases of the weighed particles (aerosols, dust, and fogs) and are used for the manufacturing of dust-proof and light gas dust-proof personnel protective equipment for respiratory organs.
Materials can be applied to equipment of other types of aerosol filters and for manufacturing filters of complex clearing air with dust content up to 1mg/m3.
Materials can be applied in the filtration of fogs, acids, alkalis, oils, provided that the quantity of the caught liquid does not exceed 20 g/m2 of filtering surface.
FNM and the manner of their manufacture are protected by Republic of Estonia patents EE03752В1 and EE03779В1 and by Euro patent ЕР0829293В1.
As a filtering layer, FNM is hydrophobic, in relation to strong acids and alkalis, spirits, paraffin hydrocarbons, glycerin, oils and mineral oil, sea and fresh water; dissolves in aromatic both chlorinated hydrocarbons and complex ethers, ketones, is swelled in softeners.
Fibres are put on a basic layer of gauze, textile or non-woven materials.
The material also can be made without a basic layer.
Materials are issued as sheets or rolls.
FNM has a high and stable electrostatic charge, providing high filtering properties in the performance of conditions of storage and operation.
FNM are issued in several basic types, distinguished by their structure. In turn, each type of a material can be subdivided into different types, distinguished by the thickness of the filtering layer and, accordingly, efficiency in catching aerosols.
As agreed upon with the customer, the release of the materials consisting of layers of fibres of a different diameter or a combination thereof, and also a different structure, is supposed.
Under the arrangement with the customer, the release of materials with other characteristics, determined on the basis of additions to specifications, included in the contract on delivery of a material, is supposed.
FNM can be applied at temperatures from - 200°С up to + 60°С and at a relative humidity of up to 98%. The recommended temperature range of operation is from -30°С up to +60°С and relative humidity is up to 80%. In excess of these limits, a probable decrease in filtering properties occurs, while mechanical properties are maintained up to 75°C, irrespective of the level of humidity.
In the case of the extended operation of materials or their storage under the influence of atomic radiation, vapours of water and organic substances, the charge flows down and the filtering properties of the materials decrease (penetration can increase by a factor of 100 times), mechanical properties do not change.
Conformity of FNM to technical requirements within 5 years from the moment of manufacturing is guaranteed in the event that the consumer observes the conditions of operation, transportation and storage established in the specifications.
|Parameter||Norm for marks|
|Superficial density of a fibrous layer, g/m2||20-30||25-35||40-55||22-28||12-18||15-25||25-35||40-60||60-80|
|Resistance to air flow at the speed of filtration is 1 cm/s, Pа, at most||3.0||4.0||6.0||6.0||6.0||8.0||17.5||35.0||45.0|
|Penetration on an oil fog with average particle diameters of 0.28-0.34 μm at a speed of 1 cm/s, %, not more||10||10||1.0||2.0||3.0||3.0||0.1||0.01||0.005|
|- explosive loading, N, not less||2.0||2.2||3.0||1.0||0.5||0.6||1.2||2.0||3.0|
|- relative lengthening at break, not less||0.5||0.5||0.5||0.5||0.5||0.5||0.5||0.5||0.5|
|The sizes of a sheet, mm:|
|- length||1500 (+30/-20)|
|- width||900 (+20/-30) or 670 (+30/-20)|
|The sizes of a roll:|
|- width, mm||700 (±20)|
|- length, m||3 - 100 (as agreed with the consumer)|