Carbon felt

When evaluating carbon felt, the most critical factors are thermal conductivity, purity (ash content), and density. For high-temperature vacuum furnaces, ensure the ash content is below 100ppm to prevent contamination. The operating temperature should be verified; standard carbon felt handles up to 1000°C in vacuum, while graphite felt can withstand up to 3000°C. Additionally, check the tensile strength to ensure it can be wrapped or installed without tearing.

PAN-based carbon felt is generally more cost-effective and offers higher mechanical strength, making it ideal for general insulation and battery electrodes (like Vanadium Redox Flow Batteries). Rayon-based carbon felt provides a softer texture, lower thermal conductivity, and better surface area characteristics, which is preferred for high-end vacuum furnace insulation where maximum thermal efficiency is required.

Suppliers should ideally hold ISO 9001:2015 certification to ensure consistent manufacturing processes. For specific applications like energy storage, request RoHS and REACH compliance reports to ensure the absence of hazardous substances. If the felt is used in aerospace or specialized electronics, verify if the supplier follows ASTM international standards for carbon material testing.

Carbon felt is primarily used as thermal insulation in vacuum and inert gas furnaces, as electrode materials in flow batteries and fuel cells, and as a filtering medium for corrosive liquids or high-temperature gases. It is also increasingly used in electromagnetic shielding and as a base material for C/C composites in the automotive and aerospace industries.

The main risk is moisture absorption during sea transit, which can degrade the material's insulation properties. Ensure the supplier uses vacuum-sealed plastic packaging and sturdy wooden crates. Another risk is specification mismatch; always request a pre-shipment sample or a third-party inspection report from agencies like SGS to verify the density and carbon content before the final balance payment.

Carbon felt pricing is often tied to the raw material costs of PAN or Rayon. For bulk orders, aim for a 10-15% discount by committing to an annual volume. On Made-in-China.com, look for 'Diamond Members' who offer flexible MOQs (e.g., 5-10kg for samples) to allow for technical validation before scaling to full container loads.

Carbon felt is lightweight but bulky, meaning you will likely be charged based on volumetric weight. To optimize shipping costs, ask the supplier to compress the felt if the application allows, or use LCL (Less than Container Load) shipping. Ensure the HS Code (typically 6815.10) is correctly declared to avoid customs delays or incorrect duty applications in your destination country.

Utilize the Secured Trading Service on Made-in-China.com to protect your payment. Never transfer funds to personal bank accounts; always use the company’s registered corporate account. Conduct a factory audit (either virtual or via a third party) to confirm the supplier has the actual production capacity and is not just a middleman.