Preparation Method Of Chemical Fiber

The preparation of chemical fibers is usually first to make a natural or synthetic polymer substance or inorganic substance into a spinning melt or solution, and then filter and measure, and then extrude it from a spinneret (plate) into a liquid stream, and then solidified into fibers. The fibers at this time are called primary fibers, which have poor mechanical properties and must go through a series of post-processing procedures to meet the requirements of textile processing and use. Post-processing is mainly aimed at stretching and heat-setting the fibers to improve the mechanical properties and dimensional stability of the fibers. Stretching is to orient the macromolecules or structural units in the nascent fiber along the fiber axis; heat setting is mainly to relax the internal stress in the fiber. The post-processing of wet-spun fibers also includes processes such as washing, oiling, and drying. When spinning filament, it can be wound into a tube after the above process; when spinning short fiber, processes such as crimping, cutting and packing must be added. Among the raw materials used to produce textiles, cotton, hemp, silk and wool (wool) have the longest history. However, natural resources are limited after all. The output of cotton is about 50 kilograms per hectare. Mulberry trees must be planted for silkworm breeding, and animal husbandry must be developed to increase wool production. Therefore, chemists began to study the use of cheaper and more abundant raw materials to spin and woven fabrics, which are chemical fibers.