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Electrographite brush panels

Electrographite brush materials have been produced in Carbon Electrode Plants – ZEW in Racibórz in the 70s of the last century. In later years their production was transferred to SZEW in Nowy Sącz. SGL CARBON GROUP S.A. company decided to end the production and to hand over all the related rights to CARBO-GRAF Sp. o.o. Thus, at the beginning of 2016 the production of electrographite materials, including E28, E28S, E30, E35 was back in Racibórz. On the basis of our decades of experience in the field of production of graphite products, using our production lines and a fixed base of raw materials from reputable suppliers, apart from other products, we currently produce electro-graphite brush material under previous names, E28 E28S, E30, E35 in accordance with current technology.

Electrographite material is characterized by stable quality, what is confirmed by the research of physical-mechanical parameters.

The production process of electrohraphite is also covered by Quality Management System, introduced, certified and audited annually by TÜV Rheinland.

1. Characteristics and application

Electrographite brush materials are widely used in the commutator electric machines of direct and alternating current. E.g. In generators, electric and exhaust traction machines. Electrographite brush materials are characterized by very good electrical conductivity and thermal conductivity. They have excellent commutator parameters, burn resistant and short-circuit current resistant.

2. Technology and the production process.

The basic raw materials for the production of electrographite materials are: pitch coke, lamp black and pitch tar binder. Additions in the form of natural graphite or electrographite are used in order to improve physical and mechanical parameters, particularly the coefficient of friction, both during the production process and usage in electric machines.

The production process is long and requires the use of many devices and processes, such as:

  • Grinding and sifting of loose materials

  • Mixing of loose materials with binder while hot

  • Grinding the mixture

  • Sifting

  • Block pressing:

  • Firing in gas furnaces

  • Graphitizing in electric resistance furnaces

  • Vacuum saturation and thermal hardening

Carbograf Sp. z o.o. has developed and implemented into production an innovative way to graphitize electrographite brush panels by using a process of induction heating. The advantage of this process is achieving repeated parameters of brush panels. The applied system of induction heating up to the temperature of 2600 – 28000C allows for accurate control of the graphitizing process. As a result obtaining a homogeneous product.

3. Standard dimensions of produced brush panels.

The panels are produced in the following dimensions:

- 93x93x39 mm

- 107x107x39 mm
Dimensional tolerances +/- 2 mm

4. Physical-mechanical parameters
5. Commutator parameters