Esfil Tehno AS
Esfil Tehno AS

Filtering polymeric fibrous materials FPP

Filtering Polymeric Fibrous Materials (FPP) are intended for thin clearing air and gases of the weighed particles (aerosols, dust, and fogs) and are used for the manufacturing of dustproof and light gas dustproof 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 to a filtration of fogs, acids, alkalis, and oils, provided that the quantity of the caught liquid does not exceed 20 g/m2 of filtering surface.

FPP represents a layer of ultra thin polymeric fibres from polyvinylchloride chlorinated (CPVC). The filtering layer of FPP is hydrophobic, resistant to strong acids and alkalis, spirits, paraffin hydrocarbons, glycerine, oils and mineral oil, sea and fresh water, is dissolved in aromatic and chlorinated hydrocarbons and complex ethers and ketones, and swells in plasticizers.

Fibres are put on a basic layer of gauze, textile or non-woven materials. The material also can be made without a basic layer.

The layer of fibres can be executed as:

  • A friable homogeneous layer;
  • A friable internal layer with the condensed external surface (external surfaces);
  • A condensed homogeneous layer;
  • Other structure - as agreed with the customer.

Materials are issued as sheets or rolls.

FPP has a high and stable electrostatic charge, providing high filtering properties, in the performance of conditions of storage and operation.

For specialists

FPP in issued in two basic types: FPP-70 and FPP-15, with fibres differing by an average diameter.

In turn, each type of a material is subdivided into some marks, distinguished by the thickness of the filtering layer and, accordingly, the efficiency in catching aerosols.

As agreed with the customer, the release of the materials consisting of layers of fibres of a different diameter or their combination, and also different structure is supposed. In this case, the characteristics of the material are defined on the basis of additions to specifications.

Filtering materials of the basic type (as a friable internal layer with a condensed external surface, placed on a basic layer of gauze or a non-woven material) should correspond to the norms specified in the table.

Designation of parameter Norm for the basic marks
FPP-70 FPP-15
0.2 0.3 0.5 0.6 0.8 1.5 3.0 4.5
Surface density of a fibrous layer, g/m2 20-30 25-35 30-40 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 8.0 17.5 35.0 45.0
Penetration on an oil fog with particles of average diameters 0.28-0.34 microns at a speed of 1 cm/s, %, at the most:
- at acceptance tests 4 3 0.5 0.5 0.3 0.01 0.005 0.0001
- During warranty period 10 10 1.0 3.0 3.0 0.1 0.01 0.005
Mechanical properties:
- Explosive loading, N, at least 2.0 2.2 3.0 0.5 0.6 1.2 2.0 3.0
- Relative lengthening at break, at least 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
The sizes of a sheets, mm:
- length 1480 - 1530
- width 850 - 900 või 670 - 690
The sizes of a roll:
- width, mm 680 - 720
- length, m 3 - 100 (as agreed with the consumer)


  • One cloth in the nominal size 1500 х 670 mm is accepted for 1 m2, one cloth in the nominal size 1500 х 880 mm accepted for 1.35 m2.
  • As agreed with the consumer, other sizes of cloths and rolls are supposed, thus commercial recalculation of the area is made.
  • In a roll of material, connections at the basic layer are supposed by the pasting, welding or sewing together of separate pieces in a length of no more than 10 m, in a quantity of no more than three per 100 m.

The material can be applied at temperatures from -200°С up to +60°С and relative humidity up to 98%. The recommended temperature range of operation is from -30 up to +60°С and relative humidity up to 80%. In excess of these limits, a decrease in filtering properties is probable, mechanical properties are maintained up to 75 °C, irrespective of humidity.

In the case of the extended operation of a material or its storage under the influence of atomic radiation, vapours of water and organic substances, the charge flows down and the filtering properties of the material decrease (penetration can increase by up to 100 times), mechanical properties do not change.

The manufacturer guarantees conformity of FPP to the requirements of the present specifications for a period of 5 years from the moment of manufacturing, in the case of the observance by the consumer of conditions for operation, transportation and storage, established in the specifications.