tailieunhanh - Materials Handbook 15th ed - G. Brady_ H. Clauser_ J. Vaccari (McGraw-Hill_ 2002) Episode 6

Tham khảo tài liệu 'materials handbook 15th ed - g. brady_ h. clauser_ j. vaccari (mcgraw-hill_ 2002) episode 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 400 FLUOROPLASTICS There are three major classes of fluoroplastics. In order of decreasing fluorine replacement of hydrogen they are fluorocarbons chlorotrifluoroethylene and fluorohydrocarbons. There are two fluorocarbon types tetrafluoroethylene PTFE or TFE and fluorinated ethylene propylene FEP . PTFE is the most widely used fluoroplastic. It has the highest useful service temperature 500 F 260 C and chemical resistance. FEP s chief advantage is its low-melt viscosity which permits it to be conventionally molded. Zymaxx composite of Du Pont is a carbon-fiber-reinforced PTFE produced in stock shapes and custom-machined parts for applications in the chemical glass and petroleum processing industries. The material combines resistance to chemicals compressive creep and wear with toughness and dimensional stability. Teflon of Du Pont is a tetrafluoroethylene of specific gravity up to . It was discovered by Du Pont scientist Dr. Roy J. Plunkett in 1938 and has since become a household word primarily because of its nonstick surface. The tensile strength is up to 3 500 lb in2 MPa elongation 250 to 350 dielectric strength 1 000 V mil X 106 V m and melting point 594 F 312 C . It is water-resistant and highly chemical-resistant. Teflon S is a liquid resin of 22 solids sprayed by conventional methods and curable at low temperatures. It gives a hard abrasion-resistant coating for such uses as conveyors and chutes. Its temperature service range is up to 400 F 204 C . Frelon is a Teflon compound used to line aluminum bearings. Teflon fiber is the plastic in extruded monofilament down to in cm in diameter oriented to give high strength. It is used for heat-and chemical-resistant filters. Teflon tubing is also made in fine sizes down to in cm in diameter with wall thickness of in cm . Teflon 41-X is a collodial water dispersion of negatively charged particles of Teflon used for coating metal parts by electrodeposition. Teflon FEP is .