Flexible graphite materials are non-fibrous materials. The flexible graphite is made into a sheet and then molded into a sealing packing for use. Flexible graphite is also called expanded graphite, which removes impurities in natural flake graphite. After being treated with strong oxidizing mixed acid, it becomes graphite oxide. The graphite oxide is heated to liberate carbon dioxide, and its volume expands sharply, turning into a loose, soft and flexible graphite. The main features are:
1. Excellent heat resistance and cold resistance. Flexible graphite has almost no change in its physical properties from an ultra-low temperature of -270 degrees to a high temperature of 3650 degrees (in non-oxidizing gas), and it can also be used up to 600 degrees in the air;
2. Excellent chemical resistance. In addition to strong oxidizing media such as nitric acid and concentrated sulfuric acid, flexible graphite has almost no corrosion in other acids, alkalis and solvents;
3. Good self-lubricity. Flexible graphite, like natural graphite, is prone to sliding between the layers under the action of external force, so it has lubricity, good anti-wear properties, and low friction coefficient;
4. High rebound rate. When the shaft or sleeve has radial circle runout due to eccentricity in manufacturing, installation, etc., it has sufficient floating performance. Even if the graphite cracks, it can be tightly sealed to ensure a tight fit and prevent leakage.