Research and development on the low carbon content graphite sheet is one area of graphite sealing material. Actually,to some instruments such as farm equipment , extensive chemical machinery,it’s no need to use the high carbon content flexible graphite sheet.it’s enough that If the sealing property could be better than the asbestine,and under this situation,it could reduce costs and selling price,and it also could promote the replace of flexible graphite sheet.
As per the process flow:
Expandable graphite > High temperature expansion > Pre press > Thermal treatment > molded press > Further repression,the expandable graphite could be process to the graphite sheet.
According to the study showing that,the appropriate reduction of the carbon content could totally satisfied to the seal requirements of general industrial seals. Mainly from the following aspects to characterize:
1) The infulance to the mechanical property of carbon content and impurity.
Demonstrated by the experiment,the intensity and purity of graphite sheet are proportional,under the situation of low carbon content,the tensile strength is inversely proportional to carbon content,apparently,the impurity has an important influence to the mechanical property.
2) The infulance to the air tightness of carbon content and impurity.
Use the gaskets made of the flexible graphite sheet to do the air tightness test,and the results showed that the leakage rate has little relationship with the carbon content,with the increase of the carbon content,the change of the sealing properity is not obvious,and all the testing samples could meet the German flexible graphite gasket gas tightness requirements,in addition,the impurity also has a little influence with the leakage rate.
The influence of the carbon content is not obvious,and still could maintain the good sealing property,however,the price will be fall by 50%.