CS218705B1 - Carbon sliding material bonded with phenol formaldehyde resin - Google Patents

Abstract

The invention relates to a carbon sliding material bonded with phenol-formaldehyde resin, the filler of which is composed of 78% petroleum coke, 10% graphite, 8% microasbestos and 4% molybdenum silicate, with at least 50% of the petroleum coke content being heat-treated at a temperature of 2400 to 2800 °C, thereby achieving low wear of the sealing elements of rotary seals and other oil-free machine parts made from it, e.g. used in gas meters

Description

(54) Carbon sliding material bonded with phenol-formaldehyde resin

FIELD OF THE INVENTION The present invention relates to a carbon sliding material bonded with phenol-formaldehyde resin, the filler of which is composed of 78% petroleum coke, 10% graphite, 8% micro-asbestos and 4% molybdenum silicon, at least 50% of the petroleum coke content being heat treated at 2400 to 2800 ° C, thereby achieving low wear of the sealing elements of the rotary seals and other non-lubricating machine parts produced therefrom, for example the gas meters used.

SUMMARY OF THE INVENTION The present invention provides a material composition of a carbon sliding material bonded with phenol-formaldehyde resin for machine parts requiring low friction coefficient and low wear. For example: sealing elements of rotating seals, bearings, gas meter parts and the like.

Phenol-formaldehyde materials are known in which some of these materials are used as fillers, e.g. textile fibers, wood flour, ground slate, graphite. The disadvantage of sliding machine parts made of these materials is the high coefficient of friction and high wear. The specific values of the coefficient of friction and service life depend on the quality of the counterpart and the medium in which they operate, such as different liquids, air, gas, as well as their temperature, etc. hardness, resulting in higher wear.

The present invention relates to a carbon glidant bonded with phenol-formaldehyde resin, wherein the filler is composed of 78% petroleum coke finer than 0.04 mm, 10% finer graphite; it as 0.01 mm, 8% micro-asbestos finer than 0.7 mm and 4% molybdenum disulphide; not more than 0.01 mm, characterized in that 50% of the kerosene coke present is present; in the filler it is heat treated at a temperature of 2400 to 2800 ° C. The filler components affect the properties of the final product as follows: =

Coke heat treated to a temperature of 2400-2800 ° C gives the product hardness and sliding properties, micro-asbestos increases fracture strength and improves; is the material properties during processing, graphite and molybdenum silicon improves the sliding properties under dry friction even at temperatures above 100 ° C.

The material prepared according to the present invention exhibits mechanical properties similar to those of phenol-formaldehyde materials filled with textile fibers, ground slate, wood flour, graphite and good sliding properties as well. they have classic carbon materials, while their lifetime exceeds the two compared materials.

Sealing ring made of material according to the invention, in dry friction on a steel counter-ring with a hard metal deposit at a pressure of 0.12 MPa and a peripheral speed of 1.25 m / s; has a wear of 0.05 mm after 200 hours of operation.

The ring made of phenol-formaldehyde resin filled with wood meal has a wear of 0.35 mm under the mentioned conditions. Other advantages of the new material are also reflected in the economic area. The cost of producing the proposed material is at the level of conventional filled phenol-formaldehyde materials, but is up to 20 times lower than conventional carbon materials.

An example of use of the present invention is the manufacture of a gland packing ring.

218705-

When preparing the filler, the mixer is placed in a mixer heated to 120 ° C weigh the following raw materials: grain' Ground petroleum coke jemn. than (mm) composition % at 2600 ° C 0.04 39 Ground petroleum coke 0.04 39 Graphite, netol powder 0.01 10 Microazbest 0.7 8 Molybdenum disulphide 0.01 4

The filler is agitated for 1 hour at 110-120 ° C for complete homogenization as well as evaporation of moisture and sieved on a vibrating screen with a mesh size of 0.7 mm to break up any clumps.

When preparing the press mixture, the following shall be weighed into the mixer:

Prepared filler 50 parts

Phenol-novolak resin 70 ° C ground to a grain size of max. 2 mm 43 parts

Hexamethylenetetramine 3 parts

Stearin 2 parts

Magnesium oxide 2 parts

The mixture is homogenized for one hour and calendered on a fractional calender having a roller speed ratio of 1: 1.2. Slower roller temperature 100-110 ° C. The calendering time of a single batch is 10 minutes.

After cooling, the mixture is crushed on a jaw crusher, ground on a pin disintegrator and sieved through a 2 mm mesh sieve and the larger portion is ground again. The mixture is tableted to tablets having a thickness of 8 to 10 mm and a specific pressure of 20-30 MPa.

When pressing the O 36/26 x 8 mm O-rings, the granulated mixture is weighed into a press. machine and cured under a pressure of 60 MPa at 160 ° C for 8 minutes. After cooling, the product is deburred and the functional area is snapped to a roughness of Ra Ra 0.8.

Achieved physical properties:

Bulk density (g / cm ³ ) 1.53

Compressive strength (MPa)

Hardness HR _b 5/20 75

Dry wear (mm) 0.05 on a counter ring with hard metal deposit at pressure

0.12 MPa, peripheral speed 1.25 m / s in 200 h.

Claims (1)

SUBJECT Carbon lubricant bonded by phenol-formaldehyde resin, whose filler consists of 78% petroleum coke finer than 0,04 mm, 10% graphite finer than 0,01 mm, 8% micro-asbestos finer than 0,7 mm and 4% INVENTION molybdenum disulphide finer than 0.01 mm, characterized in that at least 50% of the kerosene coke present in the filler is heat treated at 2400 to 2800 ° C.