Flexible Carbon & Graphite Felt Products—Rayon Precursor

Carbon and graphite felts are designed for use as high temperature insulation in resistance or induction heated vacuum furnaces and inert gas furnaces. Made of carbon or graphite fibers, these materials have low thermal conductivity and vapor pressure. They are used
in oxidizing atmospheres up to 350°C (662°F) and in protective atmosphere or vacuum up to 3000°C (5432°F).

Carbon and graphite felts are considerably less expensive and more effective than metallic radiation shields and may be used to replace them, with power savings of up to 75%. The low specific heat and low density permit rapid heating and cooling of furnaces. Although carbon and graphite felts are slight electrical conductors, in a inductive field under 12 kilohertz, they do not couple and heat up. At higher frequencies, the tendency to couple can be reached by placing longitudal slits in the felt. Carbon and graphite felts are used as backing strips for soldering and welding. Carbon and graphite felts are easy to cut using scissors or knife and have small bending radii. The felts have high purity levels with low sulfur content and have virtually no outgassing and are not wetted by most molten metals.

They are available in a variety of thicknesses and widths. Carbon Felt is premium quality carbon felt exhibiting greatly reduced gas evolution and higher oxidation resistance than standard carbon grades. It is not equal to graphite in these respects, but it is a lower cost solution for applications of lower temperatures where chemical purity is not as critical. Carbon Felt is processed to a minimum temperature of 1400°C. Graphite Felt is preferred for vacuum service because of its negligible gas evolution when heated to 3,000°C. It also exhibits the greatest oxidation resistance in the presence of trace oxidizing elements in the atmosphere. Shrinkage and water absorption are negligible. Graphite Felt has been processed to a minimum temperature of 2,500°C.