Carbon / the process of graphite materials impregnated with PTFE impregnated with phenolic resin, epoxy resin, furan resin and metal process similar, but due to using impregnated materials of different process conditions is also slightly different.
The process is as follows:
Graphite billet cleaning, canning, vacuum, input PTFE dispersion, pressure relief, remove the blank, drying, sintering, cooling furnace.
PTFE impregnated carbon / graphite materials development began in the early 1950s. At that time, British Morgan carbon company, Union Carbide Corporation figure, France Roland carbon company, SGL company, the former Soviet Union Moscow electric pole factory has both the Teflon impregnated carbon graphite materials technology research and development and the technical application in motor with brush, mechanical sealed with parts and chemical used for thermal equipment of carbon core and material production, the various kinds of industrial equipment can be used in the harsh working conditions.
PTFE impregnated carbon / graphite material permeability is not high reason is in many aspects. The first is the solid PTFE along the particle size and the problem containing water. Polytetrafluoroethylene (PTFE) size must be less than carbon graphite pore, so to the infiltration of carbon / graphite pore, scattered liquid poly tetrafluoroethylene concentration should be control of in a proper range, because the PTFE content is too high, the dispersion of unstable, prone to condensation, difficult for dipping, and content is too low, water is too much, dip stains on the effect is not good, in order to avoid suspension condensed metamorphic, dispersion liquid stirring frequently, and stored in between 10 to 30 DEG C environment.
In addition, impregnation products in the sintering process due to the expansion and contraction of PTFE and graphite expansion and contraction coefficient is different, may also lead to the impermeability of the final product.