Presentation on the production of modern chemical fibers. Presentation - artificial and synthetic fibers
The raw material for the production of artificial fibers is cellulose obtained from spruce wood and cotton waste. The raw material for the production of artificial fibers is cellulose obtained from spruce wood and cotton waste. The raw materials for the production of synthetic fibers are gases - products of the processing of coal and oil. The raw materials for the production of synthetic fibers are gases - products of the processing of coal and oil.
The production of chemical fibers is divided into three stages: 1. Preparation of the spinning solution. All chemical fibers, except mineral ones, are produced from viscous solutions or melts, which are called spinning. 1. Obtaining a spinning solution. All chemical fibers, except mineral ones, are produced from viscous solutions or melts, which are called spinning.
2. Fiber forming. The viscous spinning solution is passed through dies - caps with tiny holes. The number of holes ranges from 24 to 36 thousand. Streams of solution flowing from the dies harden, forming solid thin threads. Next, the threads from one spinneret are combined into one common thread on spinning machines, pulled out and wound onto a bobbin. 2. Fiber forming. The viscous spinning solution is passed through dies - caps with tiny holes. The number of holes ranges from 24 to 36 thousand. Streams of solution flowing from the dies harden, forming solid thin threads. Next, the threads from one spinneret are combined into one common thread on spinning machines, pulled out and wound onto a bobbin.
3. Fiber finishing. The resulting threads undergo washing, twisting, and heat treatment (to fix the twist). Some fibers are bleached, dyed and treated with a soap solution to make them soft. 3. Fiber finishing. The resulting threads undergo washing, twisting, and heat treatment (to fix the twist). Some fibers are bleached, dyed and treated with a soap solution to make them soft.
Viscose fiber is pure cellulose obtained from spruce wood without any impurities. Depending on its purpose, viscose can have a shiny or matte surface. By changing the shine, thickness and crimp of the fibers, viscose fabric can be given the appearance of silk, cotton or wool. By using thickened viscose threads, you can achieve an imitation of linen. Viscose fiber is pure cellulose obtained from spruce wood without any impurities. Depending on its purpose, viscose can have a shiny or matte surface. By changing the shine, thickness and crimp of the fibers, viscose fabric can be given the appearance of silk, cotton or wool. By using thickened viscose threads, you can achieve an imitation of linen.
Viscose fabrics are inferior in strength to natural silk, although super-strong viscose fabrics are also produced. When wet, their strength decreases significantly - by 50-60%. Viscose absorbs moisture better than cotton, but is inferior in wear resistance. Viscose fabrics are inferior in strength to natural silk, although super-strong viscose fabrics are also produced. When wet, their strength decreases significantly - by 50-60%. Viscose absorbs moisture better than cotton, but is inferior in wear resistance. Viscose fibers burn in the same way as linen and cotton fibers: quickly, evenly, with a bright flame, smell of burnt paper, and leave easily crumbling light gray ash. Viscose fibers, unlike plant fibers, are sensitive to the action of alkalis and acids. Viscose fibers burn in the same way as linen and cotton fibers: quickly, evenly, with a bright flame, smell of burnt paper, and leave easily crumbling light gray ash. Viscose fibers, unlike plant fibers, are sensitive to the action of alkalis and acids.
The raw material for acetate fiber is cotton wood waste. Silk fabrics made from acetate fiber are very similar in appearance to natural silk and have a shiny surface. The raw material for acetate fiber is cotton wood waste. Silk fabrics made from acetate fiber are very similar in appearance to natural silk and have a shiny surface. Fabrics made from acetate fiber do not absorb moisture well, but dry quickly; They have less strength than viscose, but greater elasticity, so they hardly wrinkle and retain their shape well. Acetate does not tolerate strong heat and melts at a temperature of 210 degrees. Fabrics made from acetate fiber do not absorb moisture well, but dry quickly; They have less strength than viscose, but greater elasticity, so they hardly wrinkle and retain their shape well. Acetate does not tolerate strong heat and melts at a temperature of 210 degrees.
Fabrics made from synthetic fibers Synthetic fabrics are made from fibers obtained as a result of complex chemical reactions. They differ from each other in chemical composition, properties, and combustion character. Synthetic fabrics are made from fibers obtained through complex chemical reactions. They differ from each other in chemical composition, properties, and combustion character. In different countries, these fibers are called differently, so we will focus only on the most common fibers and fabrics made from them. In different countries, these fibers are called differently, so we will focus only on the most common fibers and fabrics made from them.
Fabrics made from polyester, lavsan, crimplene are soft and flexible, but very durable. They practically do not wrinkle, hold their shape well when heated, hold folds and pleats, do not fade in the sun, and are not affected by moths and microorganisms. Their disadvantage is low hygroscopicity. Fabrics made from polyester, lavsan, crimplene are soft and flexible, but very durable. They practically do not wrinkle, hold their shape well when heated, hold folds and pleats, do not fade in the sun, and are not affected by moths and microorganisms. Their disadvantage is low hygroscopicity. Nylon, nylon, dederon are the strongest of all synthetic fibers. Fabrics made from these fibers are harsh to the touch, have a smooth surface, are tear-resistant, abrasion-resistant, do not fade and wrinkle a little, and are not affected by moths and microorganisms. Disadvantages include poor hygroscopicity and sensitivity to high temperatures. Nylon, nylon, dederon are the strongest of all synthetic fibers. Fabrics made from these fibers are harsh to the touch, have a smooth surface, are tear-resistant, abrasion-resistant, do not fade and wrinkle a little, and are not affected by moths and microorganisms. Disadvantages include poor hygroscopicity and sensitivity to high temperatures.
Acrylic and nitron have the appearance of voluminous crimped fibers, so fabrics made from them are very reminiscent of wool. They have the same properties as polyester fabrics; they are very sensitive to high temperatures: they quickly melt, turning brown, then burn with a smoky flame. Acrylic and nitron have the appearance of voluminous crimped fibers, so fabrics made from them are very reminiscent of wool. They have the same properties as polyester fabrics; they are very sensitive to high temperatures: they quickly melt, turning brown, then burn with a smoky flame. Elastane (Lycra) is most often used in a mixture with other fibers. Elastane fibers are very elastic when stretched, capable of increasing their length seven times and then shrinking back to their original size. Elastane (Lycra) is most often used in a mixture with other fibers. Elastane fibers are very elastic when stretched, capable of increasing their length seven times and then shrinking back to their original size.
Fabrics with elastane are used in the manufacture of tight-fitting clothing: trousers, jeans, knitwear, hosiery. Such clothes fit close to the figure and do not restrict movement. Products with elastane stretch well, wrinkle little and are durable. Fabrics with elastane are used in the manufacture of tight-fitting clothing: trousers, jeans, knitwear, hosiery. Such clothes fit close to the figure and do not restrict movement. Products with elastane stretch well, wrinkle little and are durable. A comparative description of the properties of fabrics made from various fibers is presented in the table below. Fabrics are listed in descending order of properties. A comparative description of the properties of fabrics made from various fibers is presented in the table below. Fabrics are listed in descending order of properties.
Properties StrengthShrinkability Hygroscopicity Elasticity Washability NylonPolyesterLinenSilkCottonAcrylicViscoseAcetateWoolElastaneWoolCottonLinenSilkAcetateCottonLinenSilkViscoseWoolAcetateNylonAcrylicPolyesterElastaneElastaneNylonWoolSilkPolyesterAcry lViscoseCottonElastanePolyesterNylonAcrylicSilkAcetateLinenCottonViscoseWool
natural polymers (man-made fibers) or synthetic polymers (synthetic fibers). Polymers (from poly... and Greek meros share, part), substances whose molecules (macromolecules) consist of a large number of repeating units; The molecular weight of polymers can vary from several thousand to many millions. Based on their origin, polymers are divided into natural or biopolymers (for example, proteins, nucleic acids, natural rubber), and synthetic (for example, polyethylene, polyamides, epoxy resins), obtained by polymerization and polycondensation methods. Based on the shape of the molecules, linear, branched and network polymers are distinguished; organic, organoelement, and inorganic polymers are by nature. Linear and branched polymers are characterized by a set of specific properties, for example, the ability to form anisotropic fibers and films, as well as exist in a highly elastic state. Polymers are the basis of plastics, chemical fibers, rubber, paints and varnishes, adhesives, ion exchangers. The cells of all living organisms are built from biopolymers.
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Artificial and synthetic fibers
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Fibers are polymers with a linear structure that are suitable for the manufacture of threads, tows, yarns and textile materials. They are divided into: - natural - chemical.
FIBER CLASSIFICATION
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Natural fibers include fibers of natural (plant, animal, mineral) origin: cotton, linen, wool and silk. Chemical fibers are fibers manufactured in factories. In this case, chemical fibers are divided into artificial and synthetic. Artificial fibers are obtained from natural high-molecular compounds that are formed during the development and growth of fibers (cellulose, fibroin, keratin). Fabrics made from artificial fibers include: acetate, viscose, staple, modal. These fabrics are highly breathable, remain dry for a very long time and are pleasant to the touch. Today, all these fabrics are actively used by manufacturers of hosiery products, and, thanks to the latest technologies, they can replace natural ones. Synthetic fibers are obtained by synthesis from natural low-molecular compounds (phenol, ethylene, acetylene, methane, etc.) as a result of polymerization or polycondensation reactions, mainly from products of oil, coal and natural gases.
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Cotton
Cotton fiber is a thin-walled tube with a channel inside. The fiber is somewhat twisted around its axis. Its cross section has a very diverse shape and depends on the maturity of the fiber. Cotton is characterized by relatively high strength, heat resistance (130-140 ° C), average hygroscopicity (18-20%) and a small proportion of elastic deformation, as a result of which cotton products are strongly wrinkled. Cotton is highly resistant to alkalis. Cotton's abrasion resistance is low.
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Natural fibers of plant origin
Flax fiber
Flax fiber is obtained from the stem of a herbaceous plant - flax. To obtain fiber, flax stems are soaked to separate the bast bunches from each other and from adjacent tissues of the stem by destroying pectin (adhesive) substances by microorganisms that develop when the stem is wet, and then crushed to soften the woody part of the stem. As a result of this processing, raw flax, or crumpled flax, is obtained, which is subjected to scuffing and carding, after which technical flax fiber (crumpled flax) is obtained.
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Wool
Wool is the hair of sheep, goats, camels and other animals. The bulk of wool (94-96%) for textile industry enterprises is supplied by sheep farming.
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Natural fibers of animal origin
Silk
Silk is the name given to thin long threads produced by the silk glands of the silkworm (silkworm) and wound around the cocoon. Cocoon thread consists of two elementary threads (mulberries) glued together with sericin, a natural adhesive produced by silkworms. Silk is especially sensitive to ultraviolet rays, so the service life of natural silk products in sunlight is sharply reduced. Natural silk is widely used in the production of sewing threads.
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Man-made fibers
Artificial fibers are obtained from natural high-molecular compounds - cellulose, proteins, metals, their alloys, silicate glasses. The most common artificial fiber is viscose, produced from cellulose. For the production of viscose fiber, wood pulp, mainly spruce pulp, is usually used. The wood is split, treated with chemicals, and turned into a spinning solution - viscose.
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Viscose fibers are produced in the form of complex threads and fibres, their application varies. Viscose fiber is hygienic, has high hygroscopicity (11-12%), products made from viscose absorb moisture well; it is resistant to alkalis; The heat resistance of viscose fiber is high. But viscose fiber has disadvantages: - due to low elasticity, it wrinkles greatly; - high fiber shrinkage (6-8%); - when wet, it loses strength (up to 50-60%). It is not recommended to rub or twist the products. Other artificial fibers used include acetate and triacetate fibers.
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Polynose fibers are modified viscose fibers obtained from high-quality raw materials (cellulose and chemicals) through special formation and greater stretching. In their structure and properties, polynose fibers are close to cotton and can replace more expensive and valuable fine-fiber cotton. Polinose fibers have a smoother surface than viscose fibers, so they become less dirty and wash better.
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Copper-ammonia fiber is obtained from cotton fluff and refined wood pulp. Cellulose is dissolved in a copper-ammonia solution and pressed through dies. The fiber is formed using the wet method, in solutions. In terms of physical and mechanical properties, copper-ammonia fibers are superior to viscose. The fiber is even, smooth, with a soft, pleasant shine, dyes well, in a dry state it is stronger than viscose, more resilient and elastic. Copper-ammonia fiber is used in the production of knitwear, and when mixed with wool, it is used to make fabrics and carpets.
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Acetate fibers are esters of cellulose and acetic acid. The raw material for producing these fibers is treated wood or cotton fluff. Cellulose is dissolved in a mixture of acetic anhydride, acetic and sulfuric acid. The resulting triacetate is partially saponified, dissolved in a mixture of acetone and alcohol and pressed through filters. The fiber is formed using a dry method (in a stream of hot air).
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PROPERTIES OF ARTIFICIAL FIBERS
They absorb moisture worse than cotton. Not susceptible to bacteria and mold fungi.
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Synthetic fibers
First of all, synthetic fabrics quickly absorb moisture and dry very quickly. Wearing a cotton item in the heat is always uncomfortable: the clothes are almost always wet, but not so with synthetics! In addition, synthetic fabrics are strong, durable, pleasant to the body, lightweight and almost do not wrinkle. We must, of course, make a reservation that you may be allergic to them, so when you always buy an unnatural thing made from polymers, you need to remember this, maybe it just won’t suit you. Synthetics are widely used not only in the production of ordinary things, but also in sewing workwear. It is inexpensive and durable, withstands various unpleasant influences well, lightweight, and comfortable to wear in production.
Properties
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Varieties
There are two main types of synthetics: carbon chain and heterochain.
Carbon-chain polymers are polymers whose main chain of macromolecules is built only from carbon atoms.
Heterochain polymers are polymers whose macromolecules contain dissimilar atoms in the main chain.
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Synthetic fibers
Synthetic fibers are obtained from natural, low-molecular substances (monomers), which are converted into high-molecular substances (polymers) through chemical synthesis. Polyamide (nylon) fibers are obtained from caprolactam polymer, a low-molecular crystalline substance produced from coal or oil. Polyester fibers The presence of valuable consumer properties of polyester fibers has led to their widespread use in textile, knitting, and artificial fur production. Polyacrylonitrile fibers (acrylic, nitron) Nitron fiber in its properties and appearance resembles wool. Fibers in their pure form and mixed with wool are used to produce dress and suit fabrics, artificial fur, various knitwear, and curtains and tulle products.
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PROPERTIES OF SYNTHETIC FIBERS
Highly durable Elastic Abrasion resistant Poorly absorbs moisture Afraid of high temperatures Accumulates static electricity
Goals and objectives: Educational: To familiarize students with the technological process of producing chemical fibers. To familiarize students with the properties of fabrics made from artificial and synthetic fibers. Developmental: Contribute to the formation and development of students’ cognitive interest in the subject. Contribute to the formation and development of intellectual qualities of the individual. Develop logical thinking. Educational: To foster practicality and promote the development of aesthetic taste.
Production of chemical fibers Stage I: Obtaining a spinning solution. For artificial fiber: Dissolving cellulose mass in alkali. For synthetic fiber: the addition of chemical reactions of various substances. Stage II: Fiber formation. Passing the solution through dies. The number of holes in the die is thousands. The solution hardens to form hard, thin threads. Stage III: Fiber finishing. The threads are washed, dried, twisted, and treated with high temperature. Bleached, dyed, treated with soap solution.
Fabrics of synthetic origin polyester fibers polyamide fibers polyacrylonitrile fibers elastane fiber lavsan crimplen dederon nylon acrylic nitron dorlastan lycra Raw materials - gas. As a result of complex chemical reactions, fibers are obtained
Laboratory work: Determination of the composition of fabrics by their properties Properties of fabrics of a fabric sample Gloss Smoothness Softness Wrinkling Shedding Strength Dry Wet Combustion
Determination of the fibrous composition of fabric Materials, tools, devices: samples of fabrics made of artificial and synthetic fibers, a needle, a vessel with water, crucibles for igniting threads. Work order 1. Examine fabric samples. Determine which ones have a shiny surface and which ones have a matte surface. 2. Determine by touch the degree of smoothness and softness of the samples. 3. Determine the wrinkling properties of the samples by holding them in your fist for 30 seconds and then straightening them out. 4. Remove two threads from each sample. Wet one of them. First break the dry thread, then the wet one. Determine how the strength of the thread has changed. 5. Remove one thread at a time from the samples and set fire to the crucible. Analyze the type of flame, smell and combustion residue. 6. Complete the report table and determine the fiber composition of each fabric sample.
Fastening the material Option 1 1. Artificial silk fiber is a fiber: a) acetate; b) polyester. 2. Artificial fibers include: a) viscose; b) polyamide; c) acetate; d) polyester; 3. Fabrics made from artificial silk fibers have the following properties: a) do not wrinkle; b) shiny; c) hard; d) have good heat-shielding properties; e) do not slip when cutting; e) they crumble a little. 4. Shedding of sections is stronger in fabrics: a) made of wool fiber; b) nylon threads; c) cotton fiber. Option 2 1. Synthetic fibers are obtained: a) from wood; b) oil; c) plants. 2.You can determine the fibrous composition of a fabric: a) by the color of the fabric; b) combustion test; c) appearance; d) to the touch. 3. When synthetic fiber fabric burns, the following is formed: a) gray ash; b) hard dark ball; c) a crumbling black ball. 4. Hygienic properties are better for fabrics: a) made of cotton fiber; b) viscose fiber; c) polyacrylonitrile fiber.
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The main source material for the production of textile products is fiber. They can be divided into several groups. Natural fibers or natural fibers are divided into textile fibers of plant (e.g. cotton, flax, hemp), animal (wool, natural silk) and mineral (asbestos) origin, suitable for making yarn. Chemical fibers are obtained from chemical processing products of natural polymers (artificial fiber) or from synthetic polymers (synthetic fiber). The production of chemical fibers usually involves forcing a solution or melt of polymer through the openings of a spinneret into a medium that causes the resulting fine fibers to solidify. Such a medium when molding from melts is cold air, from solutions hot air (“dry” method) or a special solution - a precipitation bath (“wet” method). Available in the form of monofilament, staple fiber or a bundle of many thin threads connected by twisting.
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Natural fibers of plant origin can be divided into two groups: cotton or cotton fibers and bast fibers. Cotton commonly refers to the fibers that cover the seeds of the cotton plant. Bast fibers are the fibers contained in the stems, leaves and shells of the fruits of various plants. The most common types of bast fibers are: flax, hemp (hemp fiber), jute, etc.
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Cotton
COTTON - fibers covering cotton seeds. When it ripens, the fruits (bolls) open and raw cotton (fiber with unseparated seeds) is collected from them. The boll contains seeds covered with cellulose fibers, which can be long or short. Therefore, cotton is called long-staple or short-staple. The quality of materials produced from cotton depends on this. During processing, cotton fiber (fibers more than 20 mm long), fluff (less than 20 mm) and down (less than 5 mm) are separated from the seeds. Cotton is used to produce fabrics, knitwear, threads, cotton wool, etc. Cotton fluff and lint are used in the chemical industry as raw materials for the production of artificial fibers and threads, films, varnishes, etc. Cotton is resistant to alkalis, but decomposes under the influence of acids .
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WOOL is the fiber obtained by shearing sheep, goats, camels and other animals. The quality of wool depends on the cross-sectional thickness and length of the wool fibers. The bulk of wool processed in industry is sheep. Types of wool fibers: fluff - the most valuable thin, soft crimped fiber; transitional hair, that is, thicker, stiffer and less crimped than fluff; “dead hair” is a low-strength and hard fiber. Wool is used to produce yarn, fabrics, knitwear, felting products, etc. Wool is sensitive to the action of alkalis, which make it brittle, but on the contrary, it is resistant to acids. The chemical composition of wool is a protein substance. When wool burns, it releases the characteristic smell of burnt feathers.
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FLAX is a genus of annual and perennial herbs and shrubs of the flax family, a spinning and oilseed crop. Cultivated mainly are fiber flax in stems with 20-28% fiber, and oil flax, or curly flax, in seeds 35-52% linseed oil. Flax fibers are obtained from the bast stalk of flax. This is the first fiber that man learned to produce already in the Stone Age. Long flax fibers are made of cellulose. Linen is the strongest natural fiber. Therefore, it is used in the production of strong threads, fabrics for sails, and due to its good hygienic properties, linen fabrics are used to make linen.
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SILK - natural textile thread of animal origin; a product secreted by the glands of silkworm caterpillars. By unwinding several cocoons together, raw silk is obtained, from which twisted silk is produced, used for the manufacture of fabrics, knitwear, and sewing threads. The waste is processed into yarn for technical and other fabrics. In terms of its chemical composition, silk is a protein substance. Soft, shiny, beautiful-looking silk products, however, have low wear resistance and high cost.
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Chemical fibers are obtained from chemical processing products of natural polymers (artificial fibers) or from synthetic polymers (synthetic fibers). Polymers (from poly... and Greek meros share, part), substances whose molecules (macromolecules) consist of a large number of repeating units; The molecular weight of polymers can vary from several thousand to many millions. Based on their origin, polymers are divided into natural or biopolymers (for example, proteins, nucleic acids, natural rubber), and synthetic (for example, polyethylene, polyamides, epoxy resins), obtained by polymerization and polycondensation methods. Based on the shape of the molecules, linear, branched and network polymers are distinguished; organic, organoelement, and inorganic polymers are by nature. Linear and branched polymers are characterized by a set of specific properties, for example, the ability to form anisotropic fibers and films, as well as exist in a highly elastic state. Polymers are the basis of plastics, chemical fibers, rubber, paints and varnishes, adhesives, ion exchangers. The cells of all living organisms are built from biopolymers.
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Over the years, natural fibers have ceased to fully satisfy humans, so scientists around the world have worked to find a replacement for them. More than three hundred years ago (in 1655), the outstanding English physicist Robert Hooke published a treatise in which there was the following statement: “It is possible, apparently, to find ways to artificially obtain a sticky mass, similar to how it is formed by a silkworm... If such a mass will be found, then, apparently, an easier task will be to find a way to stretch this mass into thin threads...” But only in 1884, a student of Louis Pasteur, the French inventor Hilaire de Chardonnay, managed to obtain artificial fibers. The most common types of artificial fibers are obtained by processing cellulose. Chardonnay was the first to decide to convert cellulose into a solution using a solvent and obtain a new fiber from this solution. To do this, he pressed the resulting liquid mass through thin holes. To obtain fibers, a polymer solution or melt is forced through the finest holes of a spinning die. The resulting fibers are spun into threads used to make textiles.
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When processing waste wood and sawdust, cellulose is released. In the process of producing viscose fiber, cellulose is treated with reagents (NaOH and CS2). Viscose fiber is an artificial fiber formed from viscose; consists of hydrated cellulose. Easy to paint, hygroscopic; Disadvantages: large loss of strength when wet, easy creasing, low wear resistance can be eliminated by modifying the viscose fiber. Due to the availability of raw materials and the low cost of reagents, the production of viscose fiber is highly economical. It is used (sometimes mixed with other fibers) for the production of clothing fabrics, knitwear, and cord. In the process of producing acetate fibers, cellulose is treated with acetic anhydride, the resulting cellulose acetate is dissolved in acetone and pressed through dies.
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Acetate fibers are artificial fibers formed from solutions of cellulose triacetate (triacetate fiber) and the product of its partial saponification (acetate fibers themselves). Soft, elastic, wrinkles little, transmits ultraviolet rays; disadvantages: low strength, low thermal and wear resistance, significant electrification. They are used mainly in the production of consumer products, such as linen. World production is about 610 thousand tons.
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Polyamide fiber is a synthetic fiber formed from melts or solutions of polyamides. Durable, elastic, resistant to abrasion, repeated bending and the action of many chemical reagents; disadvantages: low hygroscopicity, increased electrification, low heat and light resistance. It is used in the production of fabrics, knitwear, tire cord, filter materials, etc. Main trade names: from polycaproamide, nylon, nylon-6, perlon, dederon, amylan, stilon; from polyhexamethylene adipinamide anide, nylon-6,6, rodianylon, nylon.
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Polyester fiber is a synthetic fiber spun from a melt of polyethylene terephthalate or its derivatives. Advantages: slight creasing, excellent light and weather resistance, high strength, good resistance to abrasion and organic solvents; Disadvantages: difficulty in dyeing, strong electrification, hardness can be eliminated by chemical modification. It is used, for example, in the production of various fabrics, artificial fur, ropes, and for reinforcing tires. Main trade names: lavsan, terylene, dacron, tetheron, elana, tergal, tesil.
