Production method of ceramic fiber

Production method of ceramic fiber

Ceramic fibers can be divided into glass (amorphous) fibers and polycrystalline (crystalline) fibers according to their composition.

1. Production method of glass fiber

The production method of glassy ceramic fiber is to melt the raw material in the resistance furnace, and the high-temperature melt stream flows out from the discharge port to the high-speed spinning spinning roller of the multi-roller centrifuge. The centrifugal force of the spinning roller will swing the high-temperature melt into fibrous material. High-temperature melt stream can also be blown into fibrous materials by sudden cooling under the action of high-speed air jet force.

2. Production method of polycrystalline fiber

There are two production methods of polycrystalline ceramic fiber: gel method and precursor method.

Colloid method: soluble aluminum salt, silicon salt, etc. are made into colloidal solution with certain viscosity, and the solution stream is converted into fiber by compressed air injection method or centrifugal disc spinning method, and then it is transformed into aluminosilicate crystal fiber by high temperature heat treatment.

Precursor method: make soluble aluminum salt and silicon salt into colloidal solution with certain viscosity, absorb the colloidal solution evenly with the precursor (expanded organic fiber), and then heat treat it to form aluminosilicate crystal fiber.

3. Service temperature of ceramic fiber

The maximum service temperature of ceramic fiber refers to the limit temperature that ceramic fiber can withstand in a short time, which is used to characterize the heat resistance of ceramic fiber products. The allowable long-term use temperature of ceramic fiber products is generally about 200 ℃ lower than the maximum use temperature. For example, the long-term use temperature of 1260 ℃ fiber products is about 1000 ℃.

In the world, ceramic fiber products are divided into four grades according to temperature, namely, 1000 ℃, 1260 ℃, 1400 ℃ and 1600 ℃. In China, ceramic fiber composition and maximum service temperature are also subdivided to meet the selection requirements of different grades of thermal insulation.