High temperature furnaces as below:
Vacuum Heat treatment furnaces
Vacuum Metal Sintering furnaces
Vacuum Ceramic Sintering Furnaces
Vacuum Graphitizing furnaces
CVD furnaces
others
All no-oxygen high temperature furnaces, the heating insulation of graphite materials is the best chocie.
Detail seems:
PAN BASED GRAPHITE FELT
RIGID GRAPHITE BOARDS
RAYON BASED GRAPHITE FELT