Introduction of Carbon Fiber Manufacturing Process -- Electromagnetic Heating Roller
作者：管理员 时间：2020-06-04 09:07 来源：未知
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Carbon fiber is the carbon content of 90% or more of the carbon fibrous material, because the carbon fiber has good tensile strength and elastic modulus, good strength, modulus, dense mansion, corrosion resistance, fatigue resistance and so on characteristics, its composite materials in the military, aerospace, rail transportation, medical equipment, industrial equipment, and other fields has been widely used, became one of the hottest composite materials.
Because the carbonization yield of PAN based carbon fiber can reach 45%, higher than other raw materials, and the industrial process is simple and easy to operate, conditions are easy to control, the cost is relatively low, especially its mechanical properties, such as mild tensile resistance, elastic modulus is very good, has become the most widely used carbon fiber production.
PAN - based carbon fiber production process
1. Spinning: 15% spinning solution of polyacrylonitrile is prepared with aqueous solvent, usually sodium thiocyanate or nitric acid, dimethyl sulfoxide, etc. PAN precursor can be prepared by wet spinning or dry spraying spinning. The prepared PAN filament is woven into cloth in weft loom and then sent to pre-oxidation processor for pre-oxidation treatment.
2. Pre-oxidation treatment: the pre-oxidation treatment is carried out in two stages. Firstly, under the condition of the presence of catalyst at 200~220°C and the tension state, the polystyrene is oxidized with air (or oxidation) for 10~30min. The waste gas generated in the pre-oxidation treatment is discharged from the treatment device, and the treated fiber is sent to the carbonization processor for carbonization treatment.
3. Carbonization treatment: the carbonization process is carried out under the protection of pure argon flow (or vacuum), and the carbon fiber with disordered layer structure is transformed into carbon fiber by low-temperature carbonization (300~1000°C) and high-temperature carbonization (1000~1800C). The argon-hydrogen decomposition gas and carbonized decomposition gas produced in the carbonization process are successively discharged from the carbonized treatment device, and the carbonized fiber is sent to the graphite processor for processing.
4. Graphitization: carbon tube furnace is used for batch production during graphitization. Electric current can also be used to pass through the fiber, and heat is generated by the conductive property of the fiber itself for continuous treatment. The graphitization process is carried out under the protection of an inert gas (argon) at high heat treatment temperatures of 2000~3000°C.
The carbon fiber obtained by graphenization has been tested for non-damage and then treated with epoxy resin in a bath with dilute epoxy resin. The treated weft - free cloth enters the solvent dryer to evaporate the solvent, and then passes the damage - free test to obtain the finished carbon fiber.
The production process of raw silk mainly includes polymerization, defoaming, metering, spinning, traction, washing, oiling, drying and drawing. The carbonization process mainly includes wire release, pre-oxidation, low temperature carbonization, high temperature carbonization, surface treatment, sizing drying, winding and other processes. Drying is an important link in the spinning process, drum dryer is one of the important equipment, the equipment and drafting and heating as a whole, after the tow after washing, the moisture content of the silk is large, so to remove the moisture of the tow, eliminate internal stress, improve the stability of the fiber. In order to ensure the quality of carbon fiber precursor, need to use thermal stability and roll surface temperature uniformity of electromagnetic heating roller (electromagnetic induction heating roller) to dry.
