Definition
Man-made fibers are chemical fibers made from natural polymers through chemical treatment and mechanical processing. Man-made fibers generally have properties similar to those of natural fibers, with good moisture absorption, air permeability, and dyeability, soft touch, and luster, and are an important type of textile material.
Discovery
In 1884, the famous French chemist Chardonnay put nitrocellulose in alcohol and ether to make slender and beautiful rayon. Mass production began in 1891.
In 1890, the Germans Brenner and Fremei used the method of dissolving cellulose in a cupra solution to make cupra rayon and obtained a patent for invention.
In 1891, the British Cruise and Bevan decomposed the cellulose with strong alkali and carbon disulfide, and then made viscose rayon by spinning the spinning box under the action of centrifugal force. . It is safe and cheap, quickly became popular, and is the most widely used method of producing man-made fibers.
News report: "Ice Silk" is not so magical. Its raw material comes from our most common man-made fiber-viscose fiber. Simply put, viscose fiber is made from various natural fibers, such as cotton, wood, etc., after reprocessing, and belongs to man-made natural fibers.
Classification and fiber characteristics
Man-made fibers can be divided into three categories according to their chemical composition: regenerated cellulose fiber, cellulose ester fiber, and regenerated protein fiber. Regenerated cellulose fiber is made from cellulose-containing agricultural and forestry products, such as wood, cotton linters, etc. The chemical composition of the fiber is the same as that of the raw material, but the physical structure is changed. Cellulose ester fiber also uses cellulose as the raw material, and the fiber is obtained by spinning after esterification. The chemical composition of the fiber is different from that of the raw material. The raw materials of regenerated protein fiber are proteins such as corn, soybeans, peanuts and tallow. Here are some main man-made fibers.
(1) Viscose fiber
Viscose fiber began industrial production in 1905 and is the earliest developed variety of chemical fibers. Due to the easy availability of raw materials, low cost and wide application, it still occupies a very important position in the production of chemical fibers.
Viscose fiber is made of wood, cotton linters, bagasse, and reed as raw materials, and is made by wet spinning. The basic chemical composition of viscose fiber is the same as that of cotton fiber, so some properties are similar to cotton, such as moisture absorption and air permeability, dyeability, and textile T-addition. However, because viscose fiber has a lower degree of polymerization of macromolecular chains than cotton fiber, the degree of molecular orientation is smaller, and the arrangement of molecular chains is not as tight as cotton fiber, so some properties are worse than cotton fiber, such as dry strength closer to cotton fiber , And the wet strength is much lower than cotton fiber. In addition, the shrinkage rate of viscose fiber is relatively large, which can be as high as 10%. At the same time, because the viscose fiber swells after absorbing water, the viscose fiber fabric becomes hard in the water. In addition, viscose fiber has poor elasticity, abrasion resistance, and alkali resistance.
Viscose fiber can be spun purely or blended with natural fiber or other chemical fibers. Viscose fiber is widely used. Viscose fiber filament, also known as rayon, can be woven into various smooth and soft silk fabrics. Wool-type staple fiber is commonly known as artificial wool and is an indispensable raw material for wool spinning mills. Cotton-type viscose staple fiber is commonly known as rayon, which can be woven into a variety of colorful rayon cloth, which is suitable for making underwear, outerwear and various decorative fabrics.
The new type of viscose fiber developed in recent years-high wet modulus viscose fiber is called rich and strong fiber in my country. The macromolecules have high orientation and uniform structure. It is closer to high-quality cotton in terms of fastness, washing resistance, wrinkle resistance and shape stability. Viscose super yarn has high strength and is suitable for tire cord.
(2) Acetate fiber
Acetate fiber, also known as cellulose acetate fiber, is a man-made fiber made by spinning cellulose acetate as a raw material. Cellulose acetate is made from refined cotton linters, and is esterified with acetic anhydride to obtain cellulose triacetate (degree of esterification is 280-300). The cellulose triacetate is partially hydrolyzed with dilute acetic acid solution to obtain cellulose diacetate (degree of esterification is 200-260). Therefore, cellulose acetate is classified into two types of diacetate fiber and triacetate fiber according to the degree of esterification of the raw material cellulose acetate. Usually acetate fiber refers to diacetate fiber.
(3) Copper ammonium fiber
Copper ammonium fiber is a regenerated cellulose fiber made by spinning purified cellulose in a cupric ammonium solution. Same as viscose fiber, generally the purified "pulp" with high content of α-cellulose is used as raw material, dissolved in a cupro ammonia solution to make a spinning solution with a high concentration, and the solution is used for spinning. The fine mouth of the spinneret is pressed into a coagulation bath of pure water or dilute acid, and it is gradually solidified to form fibers while being highly stretched (about 400 times). Very fine monofilament can be produced.
Copperammonium fiber is very similar to silk in terms of appearance, feel and softness. It has great flexibility, elasticity and excellent drape. Other properties are similar to viscose fiber. The cross-section of the fiber is circular. Generally, cuproammonium fibers are spun into long fibers, which are particularly suitable for making deformed slub yarns, which are spun into thick-knotted yarns that resemble silk. Copper ammonium fiber is suitable for weaving into thin fabrics and knitted underwear, and it is comfortable to wear.
(4) Regenerated protein fiber
Regenerated protein fiber is abbreviated as protein fiber, which is made from animal or plant protein. The main varieties are casein fiber, soybean protein fiber, corn protein fiber and peanut protein fiber. Its physical and chemical properties are similar to wool, and its dyeing performance is very good. However, the general strength is lower and the wet strength is worse, so it is not widely used. Usually cut into short fibers. It can be spun purely or blended with wool, viscose fiber and nylon staple fiber.
Curing method
Artificial silk, artificial cotton, and artificial wool are all made of viscose fiber. The material is bright in color, soft in texture, but poor in abrasion resistance. If it is properly maintained, its service life can be prolonged.
1. The shrinkage rate of rayon is large, so it needs to shrink before making clothes;
2. Use fine needles for sewing needles, and fine thread for sutures;
3. Do not use washboards and high-power washing machines when washing;
4. Dry in a cool and ventilated place, and do not expose to the sun;
5. Iron when it is wet and semi-dry, and the temperature should not be high.