Industrial production, the most widely used carbon graphite material impregnant, asphalt, resin, synthetic resin, metal and metal alloys, organic lubricant, and halogen lubricant.
How to choose impregnation agent should obey some basic requirements. Select impregnating agent is an extremely important task, dipping agent determines the performance of products: chemical stability, thermal stability resistance, mechanical strength and so on.
For dipping should have the following basic requirements:
1. There are approximately graphite high chemical stability;
2. With easy-flowing pieces immersed porous graphite;
3. Can maximize the mechanical strength of graphite.
4. Good adsorption after graphite and graphite good dip impervious;
When the Baptist phenolic resin, using the following system: will be filled with resin and mounted dip products into the dipping tank immersion tank, dipping tank temperature vacuum degree (9.9 ~ 10) x 104 Pa, keep 30-35 minutes, after which, In the dipping tank pressurized to 0.4 to 0.5 MPa gauge pressure, and then held for 30 to 35 minutes. Products rapidly removed after dipping 5% alkali solution treatment, then washed. The need for such a treatment is to clear the surface of the resin products. After the water will wash products, placed in dry air for several hours, the amount of graphite inhalation resin, depending on the porosity of varying sizes, about products, about 10% by weight to 20% per surface to a depth of 15-20 mm impregnated .
To prevent the article due to the temperature rise in the use of leaving the possible outflow of the resin, the resin should be converted to the irreversible solid state. Even cured at high temperature and add the appropriate catalyst. The duration of this process takes roughly 10 hours, eight hours before the internal gauge pressure of 0.4-0.5 MPa and a temperature of heat treatment is performed at 50-SOT conditions, 1.0 ^ / h speed gradually warming; After two hours at atmospheric pressure heat treatment is performed under 1401 - 130.
When using other resins, process parameters can be changed.