Polyester Fibres Indtroduction: Polyester are polymers made by a condensation reaction taking place between small molecules, in which the linkage of the molecules occurs through the formation of estes groups. Polyesters are commonly made by interaction of a dibasic acid with a dihydric alcohol: HOOC-X-COOH+HO-Y-OH OC-X-COO-Y-OCO-X-COO-Y-OCO The formation of polyester was studied by Wallace H. Carothers of du Point during the investigation of polyesters which lead eventually to the discovery of nylon. Development of the polyesters was overshadowed, however, by the polyamide research, and it was not until 1941 that a valuable polyester fibre was discovered. in that year, J. T. Dickson and J. R. Winfield of the Calico Printers' …show more content…
Types and Sizes: The fibres are available in bright, semi-dull and dull lustres. The properties of the fibre may be modified over a range which is limited by the inherent characteristics of the polymer, each manufacturer controlling his process to produce fibres that will meet specific requirements. In general, commercial PET polyester fibres fall into two main classes, a. Regalr tenacity b. High tenacity. PET polyester fibres are produced commonly in round crosssection, but fibres of special cross-section are now available from a number of manufacturers. PET polyester fibres are thermoplastic, and lend themselves well to physical modificationc associated with this property. Crimped and textured yarns of all familiar types are available. Production: Polyethylene terephthalate is made by the condensation of terephthalic acid, or a derivative such as dimethyl terephthalate, with ethylene glycol. Reaction a. Ethylene Glycol: It is made by the catalytic oxidation of ethylene, which is obtained from petroleum craching. Ethylene oxide is produced . Hydration of this yields ethylene glycol