GH-CF17 is a high-performance carbon felt designed for high-temperature insulation. Often referred to as “hard felt”, this short-fiber viscose-based material is widely used in optical fiber manufacturing, silicon carbide crystal growth, high-temperature industrial furnaces, and semiconductor/sapphire growth applications. Its performance is equivalent to SGL’s MFA series.

Depending on the application, the product formability of carbon felt is categorized into four types:

1.Untreated carbon felt – suitable for mid-to low-end high-temperature thermal fields, with performance significantly exceeding comparable products.

2.Purified-only carbon felt – used in mid-to high-end high-temperature thermal applications, offering relatively low cost while approaching internationally leading standards.

3.Purified + coated carbon felt – designed for high-end high-temperature thermal fields, featuring high surface protection, long service life, and corrosion resistance.

4.Purified + graphitized carbon felt – intended for premium high-temperature thermal environments, offering high surface protection, long service life, corrosion resistance, and excellent thermal emissivity.

Typical Applications

GH-CF17 carbon felt insulation is widely applied in the following high-temperature insulation scenarios:

GH-CF17 carbon felt insulation offers stable physical and thermal properties suitable for demanding industrial applications.

The production process of GH-CF17 carbon felt is divided into three stages: raw material mixing & molding, high-temperature heat treatment, and post-treatment purification. The entire cycle takes approximately 5 to 7 weeks. For a detailed description and process flow chart, please refer to the following section.

1. Raw Material Mixing and Forming (3–4 weeks)

・Material preparation: Various fiber raw materials and binders are prepared.

・Mixing: Different fibers and binders are thoroughly mixed to form a homogeneous blend.

・Pressing and forming: The blended material is pressed into a felt blank with a specific shape and density.

2. High-Temperature Heat Treatment

・Carbonization: The felt blank is heated to 800–1000℃, causing non-carbon elements (e.g., hydrogen, oxygen, nitrogen) to escape as gases, yielding a pre-carbonized felt with high carbon content.

・Graphitization: The pre-carbonized felt is further heated above 2000℃, allowing carbon atoms to rearrange into a graphite crystal structure, resulting in graphite felt with enhanced thermal and electrical conductivity.

3. Post-Treatment and Purification (2–3 weeks)

・Machining/Coating: The graphite felt is cut, ground, or coated to meet specific dimensional and surface requirements.

・Purification: Further treatment at 2200℃ removes residual impurities, yielding a high-purity finished carbon felt.