Blades for pumps

These are live elements, placed in the slots of the vacuum pump rotor. The centrifugal force pushes them out of the slots, so that their edges adhere to the surface of the pump cylinder, thus creating chambers of variable volume. The blades are made of a carbon-graphite material bound by thermosetting resins – the material symbol is EG1K.

They are featured by the following physical and chemical properties:

- apparent density - above 1.75 g/cm3
- absorbability in water - below 1%
- Shore hardness "D": above 70 oSh
- thermal expansion within the range of 20-180oC - below 16.0 x 10 -6/K
- bending strength - 50 - 65 MPa
- friction factor - below 0.15

Recommended working conditions:

- linear speed – up to 12 m/s
- differential pressure – up to 3-5 bar

The range of dimensions of manufactured blades:

L - length – up to 250 mm
B - width – up to 65 mm
G - thickness – between 2 and 9 mm;

Depending on the type of pump (wet, dry) the blades are made of different materials, namely:

• carbon-graphite materials based on thermo-setting resins, e.g. epoxides - symbol of material EG1 – for dry pumps;

• thermo-setting resins or a material based on glass fibre and epoxide /symbol of material Isoval TM/ - for wet pumps.