Saturday, October 26, 2019

Carbon Fiber :: essays research papers

Carbon fiber Carbon fibers are produced by using heat to chemically change rayon or acrylic fibers. Carbonization occurs at temperatures of 1000 ° C to 2500 ° C in an inert atmosphere. Carbon fibers are converted to graphite at temperatures above 2500 ° C. Carbon and graphite fibers can also be made from pitch, a residual petroleum product. Products that use carbon fibers include heat-shielding materials, aircraft fuselages and wings, spacecraft structures, and sports equipment. You can golf, ride, sail, tennis, drive, cycle, fish, decorate or even fly Carbon Fiber! Carbon fibers are derived from one of two precursor materials Pitch and Pan. Pitch is based carbon fibers have lower mechanical properties and are therefore rarely used in critical structural applications. Pan based carbon fibers are under continual development and are used in composites to make materials of great strength and lightness. The raw material of Pan, acrylonitrile, is a product of the chemical industry and can be manufactured as follows: Acrylonitrile is used as a raw material in acrylic fibers, ABS resin, AS resin, synthetic rubber, acrylamide and other materials. Global production capacity is 4.67 million tons, approximately 60% of which is consumed for acrylic fibers. In the early manufacturing processes acetylene and hydrogen cyanide were used as a raw material, whereas today nearly all AN is manufactured using what is called the Sohio process, whereby an ammoxidation reaction are applied from inexpensive propylene and ammonia. Technological advances, particularly surrounding research into improved catalysts for the   Ã‚  Ã‚  Ã‚  Ã‚  Sohio process, are proceeding, promoted by a concern for energy conservation and lessening the environmental loading. The research aims include improved productivity, reduced byproducts, and lesser wastewater and waste gas. The Sohio process was perfected in 1960 by The Standard Oil Co. of Ohio, owing to the development of an epoch-making catalyst that synthesizes AN in a single- stage reaction using propylene and ammonia. The reaction took place using the fluid-bed od. The P-Mo-Bi group is used as the catalyst and favorable fluidized conditions are maintained by adjusting the physical properties of the catalyst. The reaction gas contains not only AN, but also acetonitrile, hydrogen cyanide and other byproduct gasses, so AN products are obtained by having the reaction gas absorbed into water, then using evaporation separation. The Sohio process was epoch-making at the time it was developed, but improvements have been made in response to the following conditions: The AN yield of approximately 60% was not very high; The process circulated and used large amounts of water, requiring a lot of

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