Method of preparing hard carbon felt

Abstract

The invention discloses a method of preparing hard carbon felt. The method includes the following steps that S1, a mesh blank prepared from short-cut pre-oxidized fiber by carding and air-laying is adopted; S2, phenolic resin with a high carbon residue rate is adopted as a precursor; S3, anhydrous ethanol is adopted as a solvent; S4, a PAN pre-oxidized fiber mesh blank is subjected to lamination and relay needle punching on a needle punching machine to the required thickness according to the process design. According to the method of preparing the hard carbon felt, the pre-oxidized fiber is adopted as a raw material, overall pre-oxidized fiber felt is obtained after relay needle punching and severs as a preform, and overall hard thermal-insulating carbon fiber felt is prepared through carbonization, impregnation, curing, graphitization and other processes; because the density of a material has large impact on the mechanical and thermal properties of the material, the density of the overall hard carbon fiber felt prepared by the method is only 0.16 g/cm<3>, the thermal conductivity of the overall hard carbon fiber felt at 1500 DEG C is 0.25 w/(m.k.), and both of the density and thethermal conductivity of the overall hard carbon fiber felt are lower than that of traditional solidified felt formed by bonding soft carbon felt and an interlayer, it is indicated that the main properties of the overall hard carbon fiber felt are better than those of the traditional carbon felt.

Description

technical field [0001] The invention relates to the technical field of hard carbon felt production, in particular to a preparation method of hard carbon felt. Background technique [0002] With the development of the photovoltaic industry, the demand for crystalline silicon is increasing day by day, and the demand for heat shields, one of the consumables for crystalline silicon ingot furnaces, is also increasing. Due to its low operating temperature (<1800°C), traditional heat insulation materials are highly polluting, and it is difficult to make a thin heat insulation layer, which increases the volume of the furnace body, thus limiting its application in crystal growth furnaces. The carbon felt, a new type of carbon insulation material, has become a popular choice due to its excellent properties such as small thermal conductivity, low heat capacity, low density, small linear expansion coefficient, high temperature resistance, strong thermal shock resistance, strong chemi...

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Problems solved by technology

It has a broad spectrum of adsorption and a large capacity. The adsorption capacity of organic vapors such as gasoline, aldehydes, phenols, alcohols, and olefins is several to dozens of times larger than that of activated carbon. It has good adsorption for inorganic gases. Carbon felt It usually requires a certain thickness and strength when used as a thermal insulation material. The traditional preparation method is to impregnate a thin layer of carbon felt with a thermosetting resin solution, and after curing, use an adhesive to bond the multi-layer thin felt to the required thickness. However, this method A large amount of binder is used in the prepared heat insulation material, which is easy to cause the density of the material to be too high, and there are obvious boundaries between the layers of thin felt, resulting in problems such as thermal field instability and high temperature cracking. For this reason, we propose A kind of preparation method of hard carbon felt is proposed to solve the above problems

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