Methods for the manufacture of chemical fibers

Nature is full of fibers and fibrous materials, and it has been consistently recognized that the science and technology of fibers were learnt from silkworms and spiders, since their fiber-producing processes are good examples of biosynthetic and biospinning techniques in which they convert nonfiber foods by enzymes into proteins in the body and then spin fibers as a cocoon or net. 

The first commercial-scale production of a manufactured fiber was achieved by a French chemist, Count Hilaire de Chardonnet. In 1884 his fabrics made of artificial silk caused a sensation at the Paris Exhibition. Two years later he built the first commercial rayon plant at Besangon, France, and secured his fame as the father of the rayon industry. However, the artificial silk invented by Chardonnet was based on cellulose nitrate, and its flammability limited its applications. In 1892 the viscose rayon process was invented by Charles F. Cross, Edward J. Bevan, and Clayton Beadle in England, and became the basis for the regenerated cellulose fiber industry. 

Technically, chemical fibers are conunonly made by extruding a thick, viscous liquid through a spinneret to form continuous filaments. In this process, the fiber-forming polymers are initially in a solid state and must be converted into a fluid state prior to extrusion. This is usually achieved by melting, if the polymers are thermoplastic, or by dissolving them in a suitable solvent if they are nonthermoplastic. If they cannot be dissolved or melted directly, they must be chemically treated to form soluble or thermoplastic derivatives. 

Melt spinning is a manufacturing process used to produce synthetic fibers. This method can be used to create fibers for fabrics or to spin glass into fine threads for fiberglass 

In this process, as the filaments exit the spinneret they immediately pass in front of a cold air blower, which rapidly cools and solidifies the strands. Then they travel down to a series of advancing rollers, which guide the filaments through various processes, such as stretching, crimping, heat setting, etc., before they are wound up as rolls of continuous filaments or cut into short staple fibers. 

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