Carbon Felt in Induction Heating Furnace - part 2

IV. High Purity and Low Pollution Characteristics

Induction heating systems are commonly used in the preparation of high-purity materials, such as semiconductor wafers and high-purity metals. The high purity (carbon content >90%, reaching 98-99%) and low ash content (<0.3%) of viscose-based carbon fiber feltmean it releases almost no volatile substances at high temperatures, avoiding contamination of the heated materials.

The purity advantage of viscose-based carbon fiber felt stems from its manufacturing process. During pyrolysis, elements such as H, N, and O volatilize in gaseous form (e.g., CO, CO₂, H₂O), ultimately yielding fibers with high carbon content. In contrast, PAN-based or pitch-based carbon fibers may contain high levels of residual metal catalysts; these impurities may migrate or volatilize at high temperatures, contaminating the process environment. Viscose-based carbon fiber, with its extremely low alkali metal and ash content, avoids this problem.

Furthermore, viscose-based carbon fiber does not produce harmful gases or particulate matter at high temperatures, which is crucial for induction heating systems that require a pollution-free environment (such as single-crystal silicon growth and high-purity metal smelting). Its high purity also ensures it does not interfere with the electromagnetic field in induction heating systems, as metallic impurities can cause electromagnetic interference or uneven heating.

V. Lightweight and Processable Formability

Viscose-based carbon fiber felt has a density of approximately 1.4 g/cm³, significantly lower than metal or ceramic insulation materials. This characteristic allows it to significantly reduce heat capacity and improve heating efficiency in induction heating systems, while also facilitating installation and maintenance.

More importantly, viscose-based carbon fiber possesses excellent processability. It can be made into various forms such as fabrics, felts, tapes, and paper. Through vacuum-assisted molding (VaRTM) and resin impregnation techniques, it can be combined with ceramic or graphite matrices to form complex-shaped insulation structures. For example, in the aerospace field, viscose-based carbon fiber reinforced phenolic resin composites are used in the thermal insulation layers of strategic weapons, and their performance directly affects the accuracy of missiles.

In industrial equipment such as monocrystalline silicon furnaces, insulation cylinders and heat insulation panels made of viscose-based carbon fiber can precisely conform to the complex shapes of induction coils or crucibles, achieving efficient heat preservation. Its flexibility and machinability also allow for further optimization of structural design through techniques such as 3D weaving and stitching (e.g., graphite yarn stitching), meeting the specific needs of different induction heating systems.

Semicorex offers high-quality carbon felt products. If you have any inquiries or need additional details, please don't hesitate to get in touch with us.