Amino acid based synthetic fibers. Synthetic

Fibers are long flexible and strong substances of limited length and small transverse dimensions, suitable for the manufacture of yarn and textiles. We talk about what natural and synthetic fiber is in the article.

Fiber classification

Fiber classification:

• natural – fibers plant origin(cotton, flax - polysaccharides (carbohydrates) having the composition (C 6 H 10 O 5)x) and animal origin (wool, silk - protein substances consisting of long polypeptide chains).
• chemical , which are divided into artificial fibers and synthetic fibers. Artificial fibers are obtained from chemical processing products of natural polymers (cellulose), for example, viscose, copper-ammonia, acetate fiber. Synthetic fibers are obtained by chemical processing of synthetic polymers. For example, nylon and nylon (polyamide fibers), lavsan (polyester fibers).

Synthetic fiber

Synthetic fibers include polyamide , polyester, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride, polypropylene, and many others. The former include substances such as nylon, anide, and enant. The main characteristics of these fibers are tensile strength and abrasion resistance. However, there are also disadvantages: low hygroscopicity, low heat resistance and high electrification. This fiber is used in the production knitwear, threads, lace, ropes and fishing nets.

Rice. 1. Polyamide fibers.

Polyamide fiber does not tolerate high temperatures. If it is heated to 160 degrees, the strength decreases sharply down to 50%.

TO polyester fibers include lavsan, dacron, terylene. Fiber has both advantages and disadvantages. Disadvantages include increased rigidity and strong electrification. Lavsan is often used to make fabric for household purposes.

Rice. 2. Polyester fibers.

TO polyacrylonitrile fibers include, for example, nitron, orlon. Nitron resembles wool in appearance. Nitron is very durable and elastic, and these properties are retained regardless of whether it is wet or dry. However, in terms of abrasion resistance, nitron is inferior to polyamide and polyester fibers.

TO polyvinyl chloride fibers include chlorine. Compared to other synthetic fibers, it is less durable, less resilient and less abrasion resistant.

Rice. 3. Polyvinyl chloride fibers.

Chlorine has the ability to accumulate electrostatic charges, which is why it is used for the production of medicinal linen

Polyvinyl alcohol fibers include, for example, vinol. A distinctive feature of this material is its high hygroscopicity; these fibers are easily dyed with dyes and are used for the production of knitwear, fabric and carpets.

What have we learned?

All existing fibers can be divided into 2 classes: chemical and natural. synthetic fibers are classified as chemical fibers. They are divided into polyester, polyamide, polyvinyl chloride and many others. The article also presents examples of synthetic fibers.

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Synthetic Fibers are fibers that produce the synthesis of simple molecules. Synthetic fibers include: lavsan, nitron, nylon, chlorine, vinol, polyethylene, polypropylene and other fibers. Depending on the raw material, the following polymers are obtained: polyamide, polyester, polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol, polyurethane. The peculiarity of the creation of chemical fiber is that the formation process is also its spinning.

Polyamide fibers. The most widely used polyamide nylon fibers. Feedstock to obtain nylon fiber is benzene And phenol(processed products coal). Processed in chemical plants into caprolactan. Capron resin is processed from capronolactan. This is a melt that is pressed through a slot from the die and comes out in the form of thin streams that solidify when blown with air. One machine can have 60 - 100 dies. Depending on the type of chemical fiber, the spinneret has a different number of holes various sizes. Fibers are drawn, twisted, processed hot water to fix the structure. Methods have also been developed for producing hollow nylon fiber, which is profiled and highly shrinkable. It is used for the manufacture of hosiery fabric, knitwear, sewing threads and technical purposes. Manufacturing processes anida And enanta similar to the production of nylon fiber.

Properties polyamide fibers: lightness, elasticity, high tensile strength, high chemical resistance, frost resistance, resistance to microorganisms and mold. The fibers dissolve in concentrated acids and phenol.

Burning fibers with a bluish flame forming a melted brown ball at the end.

Refers to polyamide silk- which is used for the manufacture of light dress and blouse fabrics and megalop- chemically modified fiber, hygroscopic, durable, abrasion-resistant, gives the fabric an increased shimmering shine. Polyamide profiled thread - trilobal used for silk-type fabrics similar in appearance to natural silk.

Polyester fibers. Lavsan produced from petroleum products. Does not change its properties when wet.

Properties lavsan fibers: light, elastic, moth-resistant, resistant to decay, destroyed by acids and alkalis, hygroscopicity is very low 0.4%. During wet heat treatment, the temperature is maintained at 140ºС. When brought into the flame, lavsan melts, then slowly burns with a yellow, smoky flame.

Polyurethane fibers. According to their own physical and mechanical properties refers to elanomers, i.e. It has high performance elastic recovery. Elongation at break 600% - 800%. When the load is removed, elasticity is immediately restored by 90%, and after a minute - 95%. These fibers are low hygroscopic - 1 - 1.5%, heat-resistant, abrasion-resistant, and dye well. They are used for the manufacture of knitwear, tapes in sports corsetry, and medical elastic products.

Polyacrylonitrine fibers(PAN). Nitron It is produced from the products of processing of coal, oil and gas. Softer and silkier to the touch than lavsan and nylon. The strength is more than half that of nylon and lavsan fibers. Elongation at break 16 - 22%, hygroscopicity 1.5%.

Nitron has a number of valuable properties: resistant to mineral acids, alkalis, organic solvents during dry cleaning, resistant to bacteria, mold, moths. In terms of heat-protective properties, nitron is superior to wool. At a temperature of 200 - 250 ° C, nitron softens. Burns with a bright, smoky flame with flashes.

Polyvinyl chloride fibers (PVC). Chlorine produced from ethylene or acetylene. It is resistant to water, acids, alkalis, oxidizing agents, does not rot, and has no shine.

According to heat-shielding properties not inferior to wool. Strength when wet does not change, and has low resistance to light weather. Wet heat treatment - at 70%. Disadvantage: low heat resistance. Chlorine does not burn, does not support combustion, and when added to the flame, a dusty smell is felt and it sinteres. Chlorine is electrified, therefore it is used for medical linen, as well as for producing embossed silk fabrics, artificial fur and workwear fabrics (fishermen, foresters, firefighters, etc.).

Resistance to aggressive environments, high mechanical strength, elasticity and other valuable qualities have made synthetic fibers indispensable for modern textile production.

These are chemical fibers obtained from synthetic polymers. Synthetic fibers are formed either from a polymer melt (polyamide, polyester, polyolefin) or from a polymer solution (polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol) using a dry or wet method.

They are produced in the form of textile and cord threads, monofilament, as well as staple fiber. The variety of properties of the original synthetic polymers makes it possible to obtain synthetic fibers with various properties, while the ability to vary the properties of artificial fibers is very limited, since they are formed from almost the same polymer (cellulose or its derivatives). Synthetic fibers are characterized by high strength, water resistance, wear resistance, elasticity and resistance to chemical reagents.

The production of synthetic fibers is developing at a faster pace than the production of man-made fibers. This is due to the availability of raw materials and rapid development raw material base, less labor intensive production processes and especially the variety of properties and high quality of synthetic fibers. Therefore, synthetic fibers are gradually replacing not only natural, but also artificial fibers in the production of some consumer goods and technical products.

Lit.: Technology of production of chemical fibers. M., 1965.

The most important groups of synthetic fibers found in the textile industry are are polyamides, polyesters, polyacrylics, polypropenes and chlorinated fibers. Common properties of synthetic fibers are lightness, strength, and wear resistance. They can be curled, compressed and given the desired stable shape under the influence of heat. Synthetic fibers absorb very little or no moisture, so products made from them are easy to wash and dry quickly. Due to their poor ability to absorb moisture, they are not as comfortable to wear on the body as natural fibers.

Prototype of the process for obtaining chemical threads served as the process of silkworm formation of thread when curling a cocoon. The hypothesis that existed in the 80s of the 19th century that the silkworm squeezes out the fiber-forming liquid through the silk glands and thus spins the thread formed the basis of the technological processes for the formation of chemical threads.

Literary sources for this article:
Great Soviet Encyclopedia;
Kalmykova E.A., Lobatskaya O.V. Materials science of clothing production: Textbook. Allowance, Mn.: Higher. school, 2001412s.
Maltseva E.P., Materials science of clothing production, - 2nd ed., revised. and additional M.: Light and food industry, 1983,232.
Buzov B.A., Modestova T.A., Alymenkova N.D. Materials science of clothing production: Textbook. for universities, 4th ed., revised and enlarged, M., Legprombytizdat, 1986 – 424.

From the history of synthetics

The production of synthetic fibers began with the release of polyvinyl chloride fiber (Germany) in 1932. In 1940, the most famous synthetic fiber, polyamide (USA), was produced on an industrial scale. Industrial scale production of polyester, polyacrylonitrile and polyolefin synthetic fibers was carried out in 1954-60.

Since 1931, apart from butadiene rubber, there were no synthetic fibers or polymers, and the only materials known at that time based on a natural polymer, cellulose, were used to make fibers.

Revolutionary changes came in the early 60s, when, after the announcement of the well-known chemicalization program National economy The industry of our country began to master the production of fibers based on polycaproamide, polyesters, polyethylene, polyacrylonitrile, polypropylene and other polymers.

At that time, polymers were considered only cheap substitutes for scarce natural raw materials - cotton, silk, wool. But soon it became clear that polymers and fibers based on them are sometimes better than those traditionally used. natural materials- they are lighter, stronger, more heat-resistant, and capable of working in aggressive environments. Therefore, chemists and technologists have focused all their efforts on creating new polymers with high performance characteristics and methods for their processing. And we achieved results in this matter that sometimes exceeded the results of similar activities of well-known foreign companies.

In the early 70s, Kevlar (USA) fibers, amazingly strong in their strength, appeared abroad, a little later - Twaron (Netherlands), Technora (Japan) and others made from aromatic polymers, collectively called aramids. Based on such fibers, various composite materials were created, which were successfully used for the manufacture of critical parts of aircraft and missiles, as well as tire cord, body armor, fire-retardant clothing, ropes, drive belts, conveyor belts and many other products.

Modern synthetics

Polyamide

The oldest synthetic fiber is nylon, the production method of which was patented in 1938 in the USA. Due to its strength and resistance to friction, polyamide is used to produce threads that are needed, for example, for darning. Polyamide is usually used in a mixture with wool or polyacrylic, and its proportion is approximately 20-30%. In this case, the wear resistance of a product knitted from such a mixture is four times higher than a product knitted from 100 percent wool.

Trade names: Nylon, Antron, Enkalon.

Polyester

A durable, wrinkle-resistant, light-resistant fiber, used mainly in the manufacture of ready-made clothing, drapery fabrics and artificial wadding.

Trade names: Dacron, Diolen, Crimplene, Terylene, Trevira.

Polyacrylic

A soft, lightweight, warm fiber that has great importance in the production of yarn for needlework. Products made from polyacrylic are soft and appear “woolen”. They are warm because the fluffy material is able to bind a lot of air. Polyacrylic fibers are relatively cheap, so they are often used together with wool.

Trade names: Dralon, Courtelle, Orion, Acrilan.

Polypropylene

Previously, the fiber was used only to produce drapery fabrics, but in last years The area of ​​application has expanded to the production of tights and sportswear, as well as yarn for needlework. Polypropene fiber is wear-resistant, easy to care for, it does not absorb moisture and directs heat-generated moisture into the outer layers of clothing, leaving a constant feeling of dryness. Therefore polypropene the best way Suitable for making sportswear.

Trade name: Meraklon.

Chloride fibers

Chloride fiber contracts strongly when exposed to heat. This property is used in the manufacture of yarn for needlework. 3-5% chloride fiber is added to the yarn, and after spinning, when the yarn is treated with hot steam, the chloride fiber contracts more than other fibers and tightens the yarn, making it fluffy. Their chloride fiber is produced so-called. underwear against rheumatism, since the static charge of the fiber has been proven to have an analgesic effect.

Trade names: Rhovyl, Thermovyl.

From solutions or melts of polymers the following is formed:

• monofilament - single threads
• complex threads, consisting of a limited number of elementary threads (from 3 to 200), are used for the production of fabrics and knitted products
• bundles consisting of very large quantity elementary threads (hundreds of thousands), are used to obtain staple fibers of a certain length (from 30 to 200 mm), from which yarn is produced
• film materials
• stamped products (parts of clothing, shoes)

Obtaining raw materials for the production of synthetics

Raw materials for artificial fibers obtained by isolating substances formed in nature: (for example: cellulose is isolated from wood, casein is isolated from milk, etc.). Pre-treatment of raw materials consists of cleaning them from mechanical impurities and sometimes chemical treatment to convert the natural polymer into a new polymer compound.

To obtain viscose fiber, wood is crushed at pulp and paper mills and boiled in an alkaline solution. The result is a gray pulp that is bleached and pressed into sheets of cardboard. Cardboard is sent to chemical fiber plants for further processing and fiber production.

Raw materials for synthetic fibers are obtained by synthesis reactions (polymerization and polycondensation) of polymers from simple substances (monomers) at enterprises chemical industry. This raw material does not require pre-treatment.

Polymerization is the process of producing polymers by sequentially attaching molecules of a low molecular weight substance (monomer) to the active center at the end of the growing chain. The monomer molecule, being part of the chain, forms its monomer grain. The number of such units in a macromolecule is called the degree of polymerization.

Polycondensation is the process of producing polymers from bi- or polyfunctional compounds (monomers), accompanied by the release of a low-molecular-weight by-product (water, alcohol, hydrogen halide, etc.).

Spinning solution

The solution or melt of the polymer from which the filaments are formed is called spinning solution.

When producing chemical fibers, it is necessary to obtain long thin threads with longitudinal orientation of macromolecules from the initial solid polymer, i.e. it is necessary to reorient the polymer macromolecules. To do this, the original polymer is transferred to a viscous-flow state (solution or melt). In a liquid (solution) or softened (melt) state, intermolecular interaction is disrupted, the distance between molecules increases and it becomes possible for them to move freely relative to each other.

Polymer dissolution is carried out for polymers having a cheap and readily available solvent. Solutions are used for artificial and some synthetic (polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride) fibers.

Polymer melting is used for polymers with a melting point below the decomposition temperature. Melts are prepared for polyamide, polyester and polyolefin fibers.

To prepare the spinning solution, the following operations are also performed:

Mixing polymers from different batches. This is done to increase the homogeneity of the solution in order to obtain fibers that are uniform in their properties throughout. Mixing is possible both after obtaining the solution and in dry form before dissolving (melting) the polymer.

Filtration of the solution. It consists of removing mechanical impurities and undissolved polymer particles by repeatedly passing the solution through filters. Filtration is necessary to prevent clogging of the spinnerets and improve the quality of the threads.

Deaeration of the solution. It is performed to remove air bubbles, which, when entering the holes of the dies, break off the resulting fibers. Deairing is carried out by keeping the solution in a vacuum. The melt is not subjected to deairing, since there is practically no air in the molten mass.

Introduction of various additives. The addition of a small amount of low molecular weight substances with specific properties allows you to change the properties of the resulting fibers. For example, to increase the degree of whiteness, optical brighteners are introduced, and titanium dioxide is added to achieve haze. The introduction of additives can give the fibers bactericidal, fire-resistant and other properties. Additives, without entering into chemical interaction with the polymer, are located between its molecules.

Fiber forming

The fiber spinning process consists of the following steps:

• pressing the spinning solution through the holes of the spinnerets,
• hardening of the flowing streams,
• winding the resulting threads onto receiving devices.

The spinning solution is fed to the spinning machine to spin the fibers. The working bodies that directly carry out the process of spinning chemical fibers on spinning machines are spinnerets. Dies are made from refractory metals– platinum, of stainless steel etc. - in the form of a cylindrical cap or disk with holes.

Depending on the purpose and properties of the fiber being molded, the number of holes in the die, their diameter and shape can be different (round, square, in the form of stars, triangles, etc.). When using spinnerets with holes of a shaped cross-section, profiled threads with different configurations are obtained cross section or with internal channels. To form bicomponent (from two or more polymers) threads, the holes of the spinnerets are divided by a partition into several (two or more) parts, each of which is supplied with its own spinning solution.

When forming complex threads, spinnerets with a small number of holes are used: from 12 to 100. Elementary threads formed from one spinneret are combined into one complex (filament) thread and wound onto a bobbin. When producing staple fibers, spinnerets with a number of holes of several tens of thousands are used. Collected together from several spinnerets, the threads form a bundle, which is then cut into staple fibers of a certain length.

The spinning solution is forced in measured doses through the holes of the spinnerets. The flowing streams enter a medium that causes the polymer to harden into thin fibers. Depending on the environment in which the polymer hardens, wet and dry molding methods are distinguished.

When spinning fibers from a polymer solution in a non-volatile solvent (for example, viscose, copper-ammonium, polyvinyl alcohol fibers), the threads harden when they enter a precipitation bath, where they undergo chemical or physicochemical interaction with a special solution containing various reagents. This is a “wet” molding method (Fig. 2a).

If the spinning is carried out from a solution of the polymer in a volatile solvent (for example, for acetate and triacetate fibers), the solidification medium is hot air in which the solvent evaporates. This is a “dry” molding method (Fig. 2b).

When melt spinning a polymer (for example, polyamide, polyester, polyolefin fibers), the medium that causes the polymer to solidify is cold air or an inert gas (Figure 2c).

The spinning speed depends on the thickness and purpose of the fibers, as well as the spinning method.

In the process of turning streams of viscous liquid into thin fibers, the spinning solution is simultaneously drawn, this process is called spinning.

Chemical fibers and threads directly after spinning cannot be used for the production of textile materials. They require additional processing.

During the spinning process, the primary structure of the thread is formed. In a solution or melt, macromolecules have a highly curved shape. Since during spinning the degree of stretching of the thread is small, the macromolecules in the thread are located with a small degree of straightening and orientation along the axis of the thread. To straighten and reorient macromolecules in the axial direction of the thread, plasticization stretching is performed, as a result of which intermolecular bonds are weakened and a more ordered structure of the thread is formed. Pull leads to increased strength and improved textile properties of the thread.

But as a result of greater straightening of the macromolecules, the threads become less extensible. Such fibers and products made from them are subject to subsequent shrinkage during dry and wet processing at elevated temperatures. Therefore, it becomes necessary to subject the threads heat setting heat treatment in a tense state. As a result of thermal fixation, partial shrinkage of the threads occurs due to the macromolecules acquiring a curved shape while maintaining their orientation. The shape of the yarn is stabilized, and subsequent shrinkage of both the fibers themselves and products made from them during WTO is reduced.

Fiber finishing

The nature of the finish depends on the molding conditions and the type of fiber.

• Removal of impurities and contaminants is necessary when obtaining threads using the wet method. The operation is carried out by washing the threads in water or various solutions.
• Bleaching of threads or fibers is carried out by treatment with optical brighteners* to subsequently dye the fibers into light and bright colors.
• Surface treatment (vivage, finishing, oiling) is necessary to make the threads suitable for subsequent textile processing. With this treatment, slip and softness, surface adhesion of elementary threads increase and their breakage decreases, electrification decreases, etc.
• Drying of threads after wet spinning and processing with various liquids is carried out in special dryers.
• Textile recycling includes the following processes:
  Twisting and fixing twist - to connect threads and increase their strength.
  Rewinding – to increase the volume of thread packages.
  Sorting – to assess the quality of threads.

Optical brighteners

Optical brighteners are fluorescent brighteners, colorless or slightly colored organic compounds, capable of absorbing ultra-violet rays in the region of 300-400 mmk and convert them into blue or violet light with a wavelength of 400-500 mmk, which compensates for the lack of blue rays in the light reflected by the material. Colorless materials acquire in this case high degree whiteness, and painted ones - brightness and contrast.

General information about textile fibers and threads.

Textile fibers are divided into two main groups: natural and chemical.

Natural – high molecular weight compounds of plant and animal origin

Chemical fibers are divided into artificial and synthetic.

Raw materials for artificial fibers:

These are natural high-molecular compounds - wood cellulose (spruce and pine chips); alginic acid from seaweed; milk, wheat, soy proteins; remnants of cotton fluff.

Raw materials for synthetic fibers:

These are products of the processing of oil, gas, and coal through synthesis, when one complex substance is obtained from several simple substances. (synthesis is a connection, this is where the name of the fibers comes from)

Fibers can be:

A) elementary– do not divide in the longitudinal direction without destruction (cotton, wool); elementary fibers of great length (tens and hundreds of meters) are called filaments

B) complex– fastened (twisted, entangled or glued together) in the longitudinal direction (flax, hemp); complex threads consist of elementary threads

In addition to natural silk, all filament threads are chemical

Short pieces of artificial or synthetic threads, 35-150 mm long, are called “staples” or staple fibers. In the production of viscose, it is known that these are threads of arbitrary length with a sharp shine, very smooth. But if a viscose strand is cut into staples and then twisted into a thread, then it loses its shine and smoothness, but also loses strength. This is how staple fiber was obtained, which became widespread in Russia after the war. Until 1970, viscose was called a staple

Textured threads– these are threads of modified structures, i.e. the complex thread is specially greatly deformed:

a) curled by twisting it and then fixing this curl by heating - get elastic a thread;

b) twist threads with different shrinkage and moisten; in this case, one thread shortens in length, while the other does not shrink; it is deformed and forms curls protruding on the surface in the form of loops. That's how they get it high-volume yarn.

c) reinforced yarn (thread) has a core and an outer sheath; another fiber (cotton, viscose) is wound (braided) onto a core of polyamide (nylon) thread; get reinforced yarn high mechanical strength, softness, fluffiness.

Obtaining artificial fiber:

Preparation of the solution:

1. The remains of spruce or pine chips are dried
2. Treat with caustic soda until swelling
3. The mass dissolves, a viscous solution is obtained
4. The fiber is formed: under pressure, the solution flows through a pipeline, is forced through dies into a sedimentary bath with aqueous solution sulfuric acid. (The die is a cap with very small holes with a diameter of 0.07-0.08 mm.)
5. When the solution interacts with sulfuric acid, hard, very long and very thin filaments are formed
6. Several elementary threads are connected into one complex thread by rotation, and, pulling it out, it is wound onto a bobbin

Thread finishing:

1. Wash - remove sulfuric acid.
2. Bleaching
3. Wash with soap to make it soft and crumbly

Synthetic threads are produced using this principle.

Chemical synthetic fibers.

Synthetic fibers have a great influence on the development of the textile industry - the range of fabrics is significantly expanded, some of their properties are improved, new types of fabrics are created through the use of mixed fibers, fabrics with specified properties can be obtained, production costs are significantly lower than natural ones.

Synthetic fibers include: nylon, lavsan, nitron.

Capron– polyamide fiber, obtained by synthesis (connection, composition, combination)– from several simple substances one complex substance is obtained from oil and coal processing products (from synthetic high molecular weight substances).

Industrial production was first undertaken in 1932 in Germany.

In Russia in 1939, the release of this fiber played a huge role in the Great Patriotic War: They were used to make aircraft tires for heavy bombers; without these tires, planes could not take off, since rubber tires could not withstand friction during acceleration, burned out, and were destroyed.

If there were no nylon, there would be no heavy bombers.

Receipt. When receiving the nylon substance, the liquid flows out of the dies in a stream, in the form of molten resin, is blown with cold air and hardens. To prevent shrinkage, the threads are pulled and treated with hot steam.

Characteristic.

A common negative property of all synthetic fibers is the absence of a unified system of pores and holes, which negatively affects their hygienic properties. This is the strongest fiber in the world, 10 times stronger than cotton, 20 times stronger than wool, 50 times stronger than viscose, although strength is lost when wet, so nylon and elastic (a type of nylon) cannot be rubbed or twisted when washing.

Nylon thread can be turned into a crimped thread - elastic, which can endlessly stretch and shrink without changing its qualities (the fiber is 100 times more resistant to bending than viscose, 10 times cotton, 20 times wool, 50 times viscose)

The big disadvantage of nylon fiber is electrification, accumulation of electrical charges, sharp shine, high surface smoothness, which causes poor adhesion to threads, which causes loops on stockings and knitwear to slip. When wearing products made from mixed fabrics, nylon fibers come out to the surface, forming pills, disrupting the structure and appearance of the products, and since nylon is strong, the pills do not disappear during wear.

Application. Nylon is used to produce thin lightweight fabrics for brides' covers, ribbons, fishing nets, parachutes, ropes, cords, fishing line, bristles, hosiery, cords for airplane and car tires, fine linen, tulle, lace, dress and costume fabrics, etc. Fibers are widely used as an additive to other fibers. (for mixed fabrics).

Currently, they will begin to produce hosiery products from micromolecular compounds, using nylon fiber nanotechnology, which will make it possible to restore a tear in tights in 15 minutes, just connect their torn edges.

Lavsan– polyester fiber.

Diolene - Germany, Terylene - England, Dacron USA, Tergal - France

In 1967, a red flag was hoisted on the flagpole of the Ostankino Tower.

Ordinary matter at such a height cannot withstand strong gusts of wind. It was decided that the flag would be made of lavsan. Fibers were first obtained in England in 1941 from petroleum and coal tar products.

The production and receipt of threads is the same as nylon.

Currently produced in many countries under different names. In our country it is produced under the name “lavsan” - an abbreviated name for the Laboratory of Macromolecular Compounds of the Academy of Sciences. developed under the guidance of Professor V.V. Kormash.

Characteristic. Mylar fiber resembles wool in appearance, is soft, warm, voluminous to the touch, is 3 times cheaper than wool, and is resistant to damage. sun rays, does not fade, it is elastic, light, very durable, very elastic, because of this the fabrics do not require ironing, the products do not wrinkle (3 times more wrinkleability than wool), and are resistant to mold, acids and alkalis. Lavsan is used in its pure form, but is mainly added to wool, viscose, and cotton. to improve their properties and reduce prices.

Products with the addition of lavsan do not wrinkle, their strength increases, and they acquire a beautiful appearance.

The disadvantages include low hygienic qualities and their ability during operation to form pilling on the surface, the ends of broken fibers rolled into balls, which gives the products an untidy appearance.

Application. Dacron is used to make fibers for carpets, fur, fabric for curtains, dresses, swimwear, knitwear, tulle; from monofilaments - mesh and bristles.

Due to the noted negative properties, it is often used in a mixture with natural and chemical fibers.

Currently, 100% lavsan - padding polyester, which is used in the production of toys, jackets, warm coats, and blankets, is widely used. A variety of padding polyester is padding polyester, halafiber, tensulate - insulation for military and flight jackets, pillow fillers. In the 60s of the 20th century, crimplene was extremely popular, which did not wrinkle at all, did not require ironing, had a beautiful texture, very bright color, but did not allow air to pass through, and did not absorb moisture well. Used crimplene on men's and women's suits

Complex lavsan threads are twisted and treated with hot air, which makes them soft and fluffy. They are used to make fabrics for knitted sports suits and towels. swimwear.

Nitron– polyacrylonitrile fibers.

Orlan. acrilan-USA, cashmilon-Japan, kurtel-England, dralon-Germany

They began producing in our country in 1963

The fiber is formed from polyacrylonitrile copolymers using a dry or wet method.

The fiber is pressed through dies, drawn and subjected to heat treatment, (spray with hot steam), fixing the arrangement of macromolecules.

Produced in the form of fibers. To give them crimp, they are corrugated in special machines. Crimped nitron fiber is similar in appearance to fine wool fiber. Nitron is a wool substitute, the “warmest” chemical thread in the world.

Characteristic. Nitron fiber has high heat-shielding properties, the warmest of all chemical fibers, with very little creasing and shrinkage, does not fade at all, dyes well, relatively high strength, abrasion resistance: 5-10 times less than nylon and lavsan; products retain 80% of their original strength for one and a half years of operation.

The fiber is fragile, electrified and pilled, but the fibers disappear during wear.

Products made from nitron can be easily washed in warm water and soap; any stains quickly disappear. Products can be cleaned with gasoline or acetone. The fiber is low hygroscopic, therefore its hygienic properties are poor. but the thermal insulation is very high

Application. In terms of light resistance, nitron fibers are superior to all textile fibers, which is why curtains, tulle, awnings and other products are made from it. In appearance and some properties it resembles wool, is produced in the form of fibers and is used similarly to wool: for the production of dress and costume fabrics, faux fur carpets, various knitwear, hats, scarves, blankets, gloves. From threads - curtains and tulle products, fishing tackle.

The combination of wool and nitron provides excellent blended fibers for beautiful, thin, warm knitted suits

Characteristics of synthetic fibers

Man-made fibers - viscose, acetate, triacetate.

Viscose - (viscous, sticky) is a concentrated solution of natural compounds - hydrated cellulose fibers

The fiber was obtained in the 80s of the 19th century by the botanist Negeli, who established that cotton fiber consists of cellulose. This discovery led to the idea that it was possible to produce a fiber similar to cotton, but from cheaper cellulosic raw materials - wood residues. Attempts to obtain such fiber were crowned with success in 1892, when the Americans Cross, Beaven, and Beadle patented the viscose method, which was improved and modernized.

Receipt. The remains of spruce chips and cotton fluff are treated with an alkali solution (sodium hydroxide), alkaline cellulose is obtained, which is then treated with carbon disulfide and the resulting raster is pressed through dies - plates with tiny holes - streams of material are obtained, which harden and form elementary threads.

Russian scientists foresaw a brilliant future for viscose fiber. DI. Mendeleev wrote in 1900: “Russia abounds in all kinds of plant products...

Fiber does not deplete the soil and is not suitable for nutrition... if we turned waste into viscose products, we would get richer than from all our trade.”

Characteristic. Viscose fiber is the most versatile of chemical fibers; it is close to cotton. The fiber has a loose structure, resembles silk in appearance, and has excellent hygienic properties. (“breathes”), has increased hygroscopicity, great strength, iron well.

The disadvantage is the sharp shine, but if the fibers of the viscose tow are cut into pieces (staples), and then pulled out and twisted into yarn, then this staple fiber loses its luster and strength decreases slightly, while maintaining the remaining properties of viscose. Products shrink a lot when washed (to 10 %), when wet, they lose up to 60% strength, so they cannot be rubbed or twisted too much.

Application. In pure form and in combination with other fibers or threads, they produce lining, dress, shirting, underwear, decorative fabrics, outerwear, linen knitwear, hosiery, textile and haberdashery products (ribbons, braid, ties), cellophane. If you stretch a viscose thread strongly, the top layer of the thread will stretch more, and the inner layer less, as a result the fiber becomes crimped; carpets are made from these threads. If we mix air into the viscose spinning solution, we get chemical reaction with highlighting carbon dioxide, voids are formed in the fiber, these hollow viscose fibers are used to produce non-sinking life suits. An improved viscose fiber is siblon, which wrinkles little, shrinks little, is durable and shiny. It is made from high quality cellulose.

Acetate fiber (cellulose acetate)

It first appeared on the world market in 1921, as a result of the work of American scientists and technologists under the leadership of Dreyfus.

Obtaining is relatively harmless and simple technological process and availability of supporting materials.

Receipt. The raw material for producing acetate fiber is the remains of cotton fluff or refined wood cellulose, treated with acetic anhydrite and acetic acid: loose flakes of primary acetate are obtained. (“vinegar” is “acetum” in Latin, which is where the name “acetate” comes from)

To obtain secondary acetate, the primary acetate is saponified - a certain amount of water is added; The resulting white flakes are squeezed out, treated in a mixture of acetone and alcohol, pressed through dies, and the mixture is evaporated using warm air, causing the threads to harden. Acetate fabric is woven from these shiny threads. In combination with other threads, the fiber is used with silk, viscose, wool and other mixed fabrics.

Characteristic. Acetate fiber is slightly hygroscopic, absorbs little moisture, soft, light, thin, elastic, shiny, but at temperatures above 85 degrees it loses its shine, becomes highly electrified, loses very little strength when wet, but has a tendency to form creases when wet, is afraid high temperatures and at 140 degrees is destroyed, not susceptible to mold, crumbles a lot, wrinkles a little, dries quickly (water drains), lightfast.

Products are ironed damp on the wrong side to avoid the formation of lasses;

cannot be cleaned with acetone, you can dissolve the fabric

Application. Currently, the production of acetate fibers and threads has sharply decreased due to low consumer demand

In the 60s of the twentieth century, fabrics were used for women's dresses, blouses. summer suits

Triacetate fiber.

Obtained from primary acetate by exposing it to a chemical composition.

Fiber formation occurs in the same way as acetate, but with low temperatures, which leads to some differences in their properties: it is characterized by low hygroscopicity, whiter, high melting and ironing temperature, it can be bleached and easier to dye,

does not require ironing, holds pleated and corrugated folds well even after washing, which improves the process of operation; crumbles a lot.

Application: They make fabrics for ties (due to low strength), tulle, bedspreads, lace, ruffled and pleated skirts, shirts

Characteristics of artificial fibers

Literature:

1. T.D. Balashova. N.E.Bushueva, I.V.Popikov. Finishing of silk fabrics; ed. “Light Industry”., 1986, Leningrad.
2. L.M. Mikhalovskaya. Textile goods. Ed.
3. Economy.; 1990, Moscow. L.V. Orlenko. Terminological dictionary
4. clothes, Legpromizdat; 1996, Moscow
5. S.I. Stolyarova, L.D. Domnenkova. Service work. Enlightenment, 1985.

Edited by I.N. Fedorova. Classes on service labor in grades 1U–UH. Moscow, Education, 1975. Synthetic fibers have a number of properties that natural fibers do not have: high mechanical strength, elasticity, resistance to action chemical substances

– , low creasing, poor flowability, poor shrinkage. All these properties are positive, so synthetic fibers are added to natural ones to obtain fabrics of improved quality. Negative properties

synthetic fibers have reduced hygroscopicity, low breathability, and high electrification when worn, so it is not recommended to wear clothes made from these fabrics for children and people with hypersensitivity to synthetic fibers.

Polyester fibers (polyester, lavsan, crimplene, etc.).

Polyamide fibers (nylon, nylon).

Polyacrylonitrile fibers (nitron, acrylic).

Elastane fiber (lycra, dorlastan).

Polyester fibers - polyester, lavsan, crimplen. Their fabrics 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. When burned, polyester fibers melt odorlessly, forming a solid ball.

Polyamide fibers- 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 absorption and sensitivity to high temperatures. Polyamide fiber, like polyester, does not burn, but melts odorlessly, forming a soft ball.

Polyacrylonitrile fibers- acrylic, nitron- have the appearance of voluminous crimped fibers, so the fabrics made from them are very reminiscent of wool. They have the same properties as polyester fiber fabrics and are very sensitive to high temperature: melt quickly, acquiring Brown color, then burn with a smoky flame to form a solid ball.

Elastane fiber- lycra, elastane, spandex - 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.

Caring for synthetic fabrics- machine washing at 40°C is recommended. Does not tolerate hot irons (may melt!)

Signs for identifying artificial and synthetic fabrics

Properties of artificial fibers