碳纤维Carbon Fiber,2,Abstract of Content ：,一、The structure and properties of carbon fiber 二、Preparation of carbon fiber 三、The use, present situation and development prospectof carbon fiber,Carbon fiber belong to polymerization of carbon, it is the opposite of organic solidshould be converted to 3 d carbon compounds, carbonization process is different, theproduct structure formation is different also. Carbon fiber and graphite fiber in the strengthand elastic modulus have very big difference, this is mainly due to the different structure. Carbon fiber is of small a layer of graphite crystal of polycrystalline, carbon content about75-95%; Graphite fiber structure and graphite similar, carbon content of up to 98-99%, impurities, quite a few. The carbon content of carbon fiber and manufacturing process of fiber carbonization and graphitization process related.,carbon fiber structure,4,carbon fiber carbonization process,Organic compounds in an inert gas heating to 1000 in a 1500 degrees, all the carbon atoms (nitrogen and hydrogen, oxygen, etc) will gradually be deported, carbon content gradually to increase, as the carbon atoms excluded, and solid alternate with in a seriesof dehydrogenation, cyclization, hand in chains and polycondensation,chemicalreaction,form carbon fiber.,5,carbon fiber graphitization process,Temperature to 2000 a 3000 degree, traces of the carbon atoms to continue to ruleout, further reaction formation fang ring plane gradually to increase, the arrangement isneat, sexual orientation significantly increased, and the 2 d a layer of graphite structureto 3 d conversion orderly structure, form of graphite fiber, the elastic chess is greatlyimproved.,6,The carbon fiber three-dimensional structure schematic drawing.,7,Carbon fiber material performance,First,carbon fiber materials electric conversion efficiency, save electric energy.Carbon fiber electrothermal body is a full blackbody materials, electric heat efficiencyof conversion 30% higher than metal fever, electric heat efficiencyabout 100%.,8,Second, carbon fiber materials conductive energy-saving performance is good,no impact on the current. Metal fever in the start or closed cable, because of themetal itself to material, can produce a moment when the most high power, can achieve maximum power rating of more than two times. At the same time in thestart, in a certain time in the not to rated condition, its power will be constant andcontinuous growth, until to rated state, would restore rated power. Carbon fiber heating cable with no impact current, in the start off to keep rated power, wont produce the moment of maximum power, so the energy saving effect than metalcable.,9,Third, carbon fiber materials with long service life. Carbon fiber fever by non-metallicmaterials for cable carbon raw materials, they can ensure the life span of the heatingelement for one thousand, the protective layer outer insulation of silicone rubber and glass QianWeiSi selection, tin plating copper wire multilayer weaves and become, the life can guarantee in more than 50 years. Under the same conditions, the service life ofcarbon fiber heating cable than metal cable much longer,10,Fourth, carbon fiber materials by good insulation. Carbon fiber heating cableinsulation is extremely strong, its insulation far outweigh the rating. In laboratorytests insulation, heating cable in 80 under normal temperature dipped into the0.8% salt water for electricity, insulation resistance for 8550 M (standard notless than 500 M , insulation intensity experiment: in the 4500 V (AC) 1 min, frequency 50 Hz compression, no flash, leakage current breakdown than 0.002 ma (standard is 0.25 ma), more of the very good security.,The preparation of Carbon Fiber,12,Generally speaking ,organic fiber are used to as a raw material to the manufacturing process of carbon fiber ：,Organic fiber,Preoxidation processing,High temperature carbonization,precursor,The conditions of choosing the precursor：High strength，less impurities，the fiber number well-distributed。Commonly used to as carbon fiber precursor ：Polyacrylonitrile fibers 、Viscose fiber 、pitch fiber,13,Viscose fiber,Pitch,PAN,difficult,complex,Low rate,abundant,High rate,easy,14,The preparation of PAN-CF,acrylonitrile comonomer initiator,polymerization,PAN,spinning,PAN fiber,Preoxidation Air medium 200-300,CarbonizationInert atmosphere1200-1500 ,GraphitizationInert atmosphere 2000-3000,15,preoxidation 200300 PAN fiber Six membered ringoxygen,16,Carbonization process of the transverse cross-linking reaction,400600 Removing the hydrogen,600130 Removing thenitrogen,17,The requirements of Graphitization,2500-3000,1,tension,2,Protective gases （Ar or He ）,3,Sealing device （water or mercury ）,4,18,The purpose of graphitization :,A messy layer of graphite structure,Similar to the graphite layered crystal structure,19,The preparation technology of viscose carbon,Sodium hydroxide,