Acrylic yarn has excellent performance. Because its properties are close to wool, it is called “synthetic wool”.
The History Of The Development Of Acrylic Fiber
At the end of the 19th century, French chemist C. Moureau synthesized polyacrylonitrile (PAN).
In 1942, German H. Rein and American GH Latham discovered dimethylformamide solvent almost simultaneously, and successfully obtained polyacrylonitrile fiber.
1950 DuPont industrialized the production of PAN fiber, Orlon, with filament.
In 1954, the Farben Bayer Company of the Federal Republic of Germany made fibers from a copolymer of methyl acrylate and acrylonitrile, which improved fiber performance, improved practicability, and promoted the development of polyacrylonitrile fibers.
In the 1960s and 1970s, acrylic fiber developed rapidly all over the world.
In the late 1980s, due to the impact of environmental pollution, some countries and regions have discontinued or resold the original production equipment.
In 2000, China became the largest producer of acrylic yarn.
2005 Solutia Company of the United States withdrew from the production of acrylic yarn.
2006 Mexico exits the production of acrylic yarn.
Characteristics Of Acrylic Yarn
Acrylic yarn is fluffy and soft. It is called “synthetic wool”. It is lighter than wool yarn and has good warmth retention. It is easy to wash and dry, and is not afraid of moth and mildew. It is suitable for knitting sweaters, wool, blankets, and can also be processed into adults. Faux fur etc.
The morphology of acrylic fibers varies with solvents and spinning methods. There are a few grooves on the longitudinal surface of the acrylic fiber, the cross-section of the dry-spun fiber is dumbbell-shaped, and the wet-spun fiber (NaSCN is the solvent) is round.
2 Stretch And Elasticity
Comparison of Tenacity and Elasticity of Acrylic Yarn, Polyester Yarn and Nylon Yarn
Elongation at break (%)
Acrylic yarn is fluffy, curly and soft, and has good elasticity, but the residual deformation after repeated stretching is relatively large, so the cuffs and necklines of acrylic fabrics are easily deformed. Its elasticity is better, second only to polyester yarn, about 2 times higher than nylon yarn, and has better shape retention.
Although the strength of acrylic yarn is not as good as that of polyester yarn and nylon yarn, compared with wool yarn, it is more than 10% lighter in weight, but its strength is more than twice as strong. The rebound elasticity of acrylic yarn is about equal to that of wool yarn when the elongation is small; when the elongation is 2%, the rebound rate of acrylic yarn is 92%~99%, while that of wool yarn is 99%. In the process of wearing, the resilience of wool fabric is higher than that of acrylic fabric.
3 Hygroscopicity And Dyeability
The hygroscopicity of acrylic yarn is low, and the moisture regain rate under general atmospheric conditions is 1.2%~2.0%. The dyeability of acrylic yarn is not good, but it has been improved after introducing the second monomer and the third monomer.
4 Acid And Alkali Resistance
Acrylic fibers are resistant to acids, oxidants and general organic solvents, but not to alkalis.
5 Light Fastness
The light resistance and weather resistance of acrylic yarn are particularly good, which is the best among all synthetic fiber yarns. After one year of exposure to the open air, its strength only drops by 20%. , the resistance to sunlight is also twice that of wool yarn and 10 times that of cotton yarn. Therefore, acrylic yarn is suitable for making curtains, curtains, tents, sails and other outdoor fabrics.
6 Heat Resistance
The softening temperature of acrylic fiber is 190°C to 230°C, second only to polyester among synthetic fibers.
7 Wear Resistance
Acrylic yarn has poor abrasion resistance, and its abrasion resistance is poor among synthetic fiber yarns. Its ability to deform under a small load is greater than that of polyester yarn but less than that of nylon yarn.
The Use Of Acrylic Yarn
The finished product of acrylic yarn has good bulkiness, good warmth retention, soft hand feeling, good weather resistance, mildew resistance and moth resistance. The warmth retention of acrylic yarn is about 15% higher than that of wool yarn. Acrylic fiber can be made into blended yarn with wool, and the products are mostly used for civil purposes, such as wool, blankets, knitted sportswear, tarpaulins, curtains, artificial fur, plush, etc. Acrylic fiber is also a raw material for high-tech products – carbon fiber.
The excellent properties of acrylic fiber make it widely used in the three major fields of clothing, apparel and industry. Polyacrylonitrile fibers can be purely spun or blended with natural fibers according to the requirements of different uses, and can be blended with wool to make blankets, carpets, etc., and can also be blended with cotton, artificial fibers, and other synthetic fibers. into a variety of clothing and interior items.
Production Of Acrylic Yarn
Acrylic yarn began to be produced industrially in 1950, and its output accounts for the third place among synthetic fibers. Since its industrial production in 1950, it has been greatly developed. In 1996, the total output of acrylic fiber in the world was 2.52 million tons, and the output in China was 297,000 tons. Since then, China has vigorously developed acrylic fiber production. Although acrylic fibers are usually called polyacrylonitrile fibers, acrylonitrile (customarily called the first monomer) only accounts for 90% to 94%, the second monomer accounts for 5% to 8%, and the third monomer accounts for 0.3% to 2.0%. %. This is due to the lack of flexibility, brittleness and difficulty in dyeing of fibers made from a single acrylonitrile polymer. In order to overcome these shortcomings of polyacrylonitrile, people use the method of adding the second monomer to make the fiber soft; adding the third monomer to improve the dyeing ability.
The raw material of acrylic yarn is cheap propylene which is a by-product of petroleum cracking: when the polyacrylonitrile copolymer is heated above 230°C, it only decomposes but does not melt, so it cannot be melt-spun like polyester and nylon fibers. Solution spinning method. Spinning can be done dry or wet. The dry spinning speed is high, which is suitable for spinning imitation silk fabrics. Wet spinning is suitable for making short fibers, which are fluffy and soft, and suitable for making wool-like fabrics.