Natural and synthetic fibers. Textile fibers and threads. Classification. Artificial fibers. Types and names of synthetic fabrics

Synthetic fibers are called fibers, upon receipt of which the synthesis of simple molecules occurs. Synthetic fibers include: lavsan, nitron, nylon, chlorin, vinol, polyethylene, polypropylene and other fibers. Depending on the raw material, the following polymers are obtained: polyamide, polyester, polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol, polyurethane. A feature of the creation of chemical fiber is that the formation process is at the same time its spinning.

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

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

Are burning fibers with a bluish flame, forming a melted brown ball at the end.

Polyamide includes 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 it is used for silk-type fabrics, similar in appearance to natural silk.

Polyester fibers. Lavsan is produced from oil refined products. Does not change its properties when wet.

Properties lavsan fibers: they are light, resilient, moth-resistant, resistant to decay, destroyed by acids and alkalis, hygroscopicity is very low 0.4%. With wet heat treatment, the temperature is maintained at 140 ° C. When introduced into a flame, lavsan melts, then slowly burns with a yellow smoky flame.

Polyurethane fibers... According to their physical and mechanical properties refers to elanomers, i.e. has high rates of elastic recovery. Breaking elongation 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, well-dyed. They are used for the manufacture of knitwear, ribbons in sports corsetry, and medical elastic products.

Polyacrylonitrine fibers(PAN). Nitron is produced from the products of processing of coal, oil and gas. They are softer and more silky to the touch than lavsan and nylon. 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-shielding 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, oxidants, does not decay, does not have a gloss.

By heat-shielding properties not inferior to wool. Strength in a wet state does not change, has a low resistance to light weather. Wet heat treatment - at 70%. The disadvantage is low heat resistance. Chlorine does not burn, does not support combustion, when introduced into the flame, the smell of dust is felt, it cakes. Chlorine is electrified, therefore it is used for medical linen, as well as for obtaining embossed silk fabrics, artificial fur and fabrics for workwear (fishermen, foresters, firefighters, etc.).

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

Obtained from non-naturally occurring polymers obtained by synthesis from natural low molecular weight compounds. A variety of raw materials and a variety of properties of the original synthetic polymers make it possible to obtain fibers with different predetermined characteristics.

The ability to preset the desired fabric properties is of great importance for the modern textile industry. New generation products are more adapted to the needs of the human body, possess multifunctional and comfortable properties.

Synthetic fibers are actively used for the production of workwear, clothing for extreme conditions and sports.

Currently, there are several thousand types of synthetic fibers, and their number is growing every year. The most common ones will be discussed below.

Polyurethane fibers

In terms of mechanical properties, polyurethane fibers are in many ways similar to rubber threads, because are capable of highly elastic reversible deformations. Such fibers impart high elasticity, abrasion resistance, resilience, dimensional stability, and crease resistance to textile materials. They are rarely used in their pure form. Their most common participation in the fabric is as skeletal threads around which other threads are wound. The disadvantage of such fibers is their low thermal stability. Already at 120 ° C, polyurethane fibers in a stretched state significantly lose their strength.

The main representatives of polyurethane fibers are trade names such as elastane, lycra, spandex, neolan, etc.

Polyamide fibers

A distinctive property of polyamide fibers is increased abrasion resistance, which is 10 times superior to cotton, 20 times to wool, and 50 times to viscose. They also have a high dimensional stability. Among the disadvantages, it should be noted low resistance to light and sweat. In the light, they turn yellow and become brittle. In addition, such fibers have low hygroscopicity and are susceptible to strong pilling. However, many of their disadvantages can be eliminated by introducing various stabilizers. Often polyamide fibers are added to mixed fabrics (with cotton, wool, viscose) in a portion not exceeding 10-15%, which practically does not impair the hygienic properties of products, but significantly improves the mechanical properties. Fibers are widely used in the production of hosiery and knitwear, for the production of sewing threads and haberdashery.

Main trade names: nylon, anid, nylon, tactel, meryl, etc.

Polyester fibers

The main property of polyester fibers is increased heat resistance, surpassing those of all natural and most chemical fibers. The production of such fibers currently occupies a leading position among chemical fibers due to their high physical and mechanical properties. They are highly resilient and highly resistant to abrasion. Fabrics made of such fibers keep their shape well, do not wrinkle, and have a low degree of shrinkage. The disadvantages are increased rigidity, tendency to peeling, strong electrification and low hygroscopicity. The disadvantages are eliminated by modifying the feedstock. From polyester fibers mixed with natural materials (cotton, wool, linen), as well as viscose, shirts, dress, suit and coat fabrics, as well as artificial fur are successfully produced. At the same time, such a disadvantage as creasing is eliminated, the abrasion resistance increases while maintaining hygienic properties.

Trade names: lavsan, polyester, terylene, etc.

Polyacrylonitrile fibers

Such fibers are called "artificial wool" due to the closeness of their mechanical properties. They have high lightfastness and heat resistance, sufficient strength, keep their shape well. Among the shortcomings, it is worth noting low hygroscopicity, a tendency to form pills, rigidity and electrification. However, all the disadvantages are eliminated by modification. In the sewing business, they are mainly used for sewing outerwear mixed with wool, artificial fur.

Trade names: nitron, acrylic, acrylane, cashmilon, etc.

Polyolefin fibers

A distinctive feature of polypropylene fibers is their low density. It is the lightest of all fiber types. In addition, their hygroscopicity is almost zero, so they do not sink in water. Such fibers have good thermal insulation properties. The disadvantage is low temperature resistance (115 C), which can be leveled by modification. It is optimal to create two-layer materials in which the lower layer is made of polyolefin fibers, and the upper one is made of hygroscopic cellulose fibers. This technology allows the bottom layer to stay dry, but wicks moisture away into the hygroscopic top layer. It is often used for sewing underwear, sportswear, as well as hosiery with increased hygiene characteristics.

Trade names: Herkulon, Ulstren, Found, Meraklon, etc.

Polyethylene fiber is mainly used for technical purposes. Trade names: spectrum, dinema, tekmilon.

PVC fiber

Polyvinyl chloride fibers have high chemical resistance, low electrical conductivity and very low heat resistance (break down at 100 C). When rubbed, the fiber acquires a high electrostatic charge, which gives the linen made from it medicinal properties in the treatment of diseases such as sciatica, arthritis. In addition, such fibers are characterized by a high degree of shrinkage after heat treatment. This property is used to obtain a beautiful embossed surface of the fabric. In addition, PVC fibers are used in the manufacture of carpet pile, artificial fur, artificial leather.

The 19th century was marked by important discoveries in science and technology. A sharp technical boom affected almost all spheres of production, many processes were automated and moved to a qualitatively new level. The technical revolution did not bypass the textile industry either - in 1890, fiber made using chemical reactions was first obtained in France. The history of chemical fibers began with this event.

Types, classification and properties of chemical fibers

According to the classification, all fibers are divided into two main groups: organic and inorganic. Organic fibers include artificial and synthetic fibers. The difference between them is that artificial ones are created from natural materials (polymers), but using chemical reactions. Synthetic fibers use synthetic polymers as raw materials, while the processes for obtaining fabrics do not fundamentally differ. Inorganic fibers include a group of mineral fibers that are obtained from inorganic raw materials.

As raw materials for artificial fibers, hydrated cellulose, cellulose acetate and protein polymers are used, for synthetic ones - carbo-chain and hetero-chain polymers.

Due to the fact that chemical processes are used in the production of chemical fibers, the properties of fibers, primarily mechanical, can be changed by using different parameters of the production process.

The main distinguishing properties of chemical fibers in comparison with natural ones are:

• high strength;
• the ability to stretch;
• tensile strength and long-term loads of different strength;
• resistance to light, moisture, bacteria;
• crease resistance.

Some special types are resistant to high temperatures and aggressive environments.

GOST chemical threads

According to the All-Russian GOST, the classification of chemical fibers is rather complicated.

Artificial fibers and threads, according to GOST, are divided into:

• artificial fibers;
• artificial threads for cord fabric;
• artificial threads for technical products;
• technical threads for twine;
• artificial textile threads.

Synthetic fibers and threads, in turn, consist of the following groups: synthetic fibers, synthetic threads for cord fabric, for technical products, film and textile synthetic threads.

Each group includes one or more subspecies. Each subspecies has its own code in the catalog.

Technology of obtaining, production of chemical fibers

The production of man-made fibers has great advantages over natural fibers:

• firstly, their production does not depend on the season;
• secondly, the production process itself, although rather complicated, is much less laborious;
• thirdly, it is possible to obtain fiber with preset parameters.

From a technological point of view, these processes are complex and always consist of several stages. First, the starting material is obtained, then it is converted into a special spinning solution, then the fibers are formed and finished.

Various techniques are used to form fibers:

• using a wet, dry or dry-wet solution;
• the use of cutting with metal foil;
• stretching from the melt or dispersion;
• drawing;
• flattening;
• gel molding.

Application of chemical fibers

Man-made fibers are widely used in many industries. Their main advantage is their relatively low cost and long service life. Fabrics made of chemical fibers are actively used for sewing special clothing, in the automotive industry - for strengthening tires. In technology of various kinds, non-woven materials made of synthetic or mineral fibers are often used.

Textile chemical fibers

As a raw material for the production of textile fibers of chemical origin (in particular, for the production of synthetic fibers), gaseous products of oil and coal processing are used. Thus, fibers are synthesized, which differ in composition, properties and combustion method.

Among the most popular:

• polyester fibers (lavsan, crimplen);
• polyamide fibers (nylon, nylon);
• polyacrylonitrile fibers (nitron, acrylic);
• elastane fiber (lycra, dorlastan).

Among artificial fibers, the most common are viscose and acetate. Viscose fibers are obtained from cellulose - mainly spruce. Through chemical processes, this fiber can be given a visual resemblance to natural silk, wool or cotton. Acetate is made from cotton waste, so it absorbs moisture well.

Man-made nonwovens

Nonwovens can be made from both natural and man-made fibers. Often nonwovens are made from recyclable materials and waste from other industries.

The fibrous base, prepared by mechanical, aerodynamic, hydraulic, electrostatic or fiberising methods, is bonded.

The main stage in the production of nonwoven materials is the stage of bonding the fibrous base, obtained in one of the following ways:

1. Chemical or adhesive (adhesive)- the formed web is impregnated, coated or sprayed with a binder in the form of an aqueous solution, the application of which can be continuous or fragmented.
2. Thermal- this method uses the thermoplastic properties of some synthetic fibers. Sometimes, the fibers that make up the nonwoven fabric are used, but in most cases, a small amount of low melting point fibers (bicomponent) is deliberately added to the nonwoven fabric at the spinning stage.

Chemical fiber industry facilities

Since chemical production covers several areas of industry, all chemical industry facilities are divided into 5 classes depending on raw materials and field of application:

• organic matter;
• inorganic substances;
• organic synthesis materials;
• pure substances and chemicals;
• pharmaceutical and medical group.

According to the type of purpose, chemical fiber industry facilities are divided into main, plant-wide and auxiliary.

Synthetic fibers

chemical fibers obtained from synthetic polymers. Synthetic fibers are spun either from a polymer melt ( polyamide, polyester, polyolefin), or from a polymer solution ( polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol) by dry or wet method. Synthetic fibers are produced in the form of textile and cord threads, monofilament, as well as staple fiber... The variety of properties of the initial synthetic polymers makes it possible to obtain synthetic fibers with different properties, while the possibilities to vary the properties of artificial fibers are very limited, since they are formed practically from one polymer ( cellulose or its derivatives). Synthetic fibers are characterized by high strength, water resistance, wear resistance, elasticity and resistance to chemical reagents.

Since 1931, apart from butadiene rubber, there were no synthetic fibers and polymers yet, and for the manufacture of fibers, the only materials known at that time based on a natural polymer - cellulose - were used.

Revolutionary changes took place in the early 60s, when, after the announcement of a well-known program for the chemicalization of the 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 the understanding came that polymers and fibers based on them are sometimes better than the traditionally used natural materials - they are lighter, stronger, more heat-resistant, capable of working in aggressive environments. Therefore, chemists and technologists have directed all their efforts to the creation of new polymers with high performance characteristics and methods of their processing. And they achieved results in this business, sometimes exceeding the results of similar activities of well-known foreign firms.

In the early 70s, Kevlar fibers (USA), striking the imagination with their strength, appeared abroad, a little later - Twaron (Netherlands), Technora (Japan) and others, made from aromatic polymers, collectively called aramids. On the basis of 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 protective clothing, ropes, drive belts, conveyor belts and many other products.

These fibers have been widely advertised in the world press. However, only a narrow circle of specialists know that in the same years Russian chemists and technologists independently created terlon aramid fiber, which is not inferior in its properties to foreign analogues. And then here were developed methods for producing SVM and armos fibers, the strength of which exceeds the strength of Kevlar by one and a half times, and the specific strength (that is, the strength per unit weight) exceeds the strength of high-alloy steel by 10-13 times! And if the tensile strength of steel is 160-220 kg / mm2, now work is underway to create a polymer fiber with a strength of up to 600 kg / mm2.

Another class of polymers suitable for the production of high-strength fibers are liquid crystal aromatic polyesters, that is, polymers with crystal properties in a liquid state. Fibers based on them are characterized not only by the advantages of aramid fibers, but also by high radiation resistance, as well as resistance to the effects of inorganic acids and various organic solvents. It is an ideal material for rubber reinforcement and highly filled composites; on its basis, samples of optical fibers have been created, the quality of which corresponds to the highest world level. And the immediate task is to create so-called molecular composites, that is, composite materials in which the molecules of liquid crystal polymers themselves serve as reinforcing components.

Molecules of ordinary polymers contain, in addition to carbon, also atoms of other elements - hydrogen, oxygen, nitrogen. But now methods have been developed for producing fibers, which are, in fact, pure polymer carbon. Such fibers have record strength (over 700 kg / mm2) and stiffness, as well as extremely low thermal expansion coefficients, high wear and corrosion resistance, high temperatures and radiation. This allows them to be successfully used for the manufacture of composite materials - carbon plastics, used in the most critical structural units of high-speed aircraft, rockets and spacecraft.

The use of CFRP turns out to be economically very profitable. Per unit weight of a product made from it, you need to spend 3 times less energy than a product made of steel, and 20 times less than that of titanium. A ton of CFRP can replace 10-20 tons of high alloy steel. A pump turbine made of carbon fiber and suitable for pumping mineral acids at temperatures up to 150 ° C is half the price and lasts six times longer. The complexity of manufacturing parts of complex configuration is also reduced.

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

In 1968 the world production of synthetic fibers was 3760.3 thousand. T(about 51.6% of the total production of chemical fibers). For the first time, the production of synthetic fibers on an industrial scale was organized in the mid-30s. 20th century in the USA and Germany.

Nylon

Fiber from polyamide resins in our country is called nylon and anid, their quality is almost the same as each other.

Nylon or nylon fiber is a white-transparent, very strong substance. The elasticity of nylon is much higher than silk. Capron belongs to polyamide fibers. Capron is made synthetically in our factories and from our materials. The feedstock is derived from amino acids. Capron can be considered as a product of the intramolecular interaction of the carboxyl group and the amino group of the 6-aminohexanoic acid molecule:

Simplified conversion of caprolactam into polymer, from which nylon fiber is produced, can be represented as follows:

Caprolactam in the presence of water is converted into 6-aminohexanoic acid, the molecules of which react with each other. As a result of this reaction, a high molecular weight substance is formed, the macromolecules of which have a linear structure. Individual polymer units are 6-aminohexanoic acid residues. The polymer is a resin. To obtain fibers, it is melted and passed through spinnerets. The polymer jets are cooled by a flow of cold air and turn into filaments, which, when twisted, form filaments.

After that, nylon is subjected to additional chemical treatment. The strength of the nylon depends on the technology and the thoroughness of the production. The finally finished nylon is white-transparent and very durable material. Even a nylon thread with a diameter of 0.1 millimeter can withstand 0.55 kilograms.

Abroad, synthetic fiber of the nylon type is called perlon and nylon. Capron is produced in several varieties; crystal-transparent nylon is more durable than opaque with a cloudy yellowish or milky shade.

Along with high strength, nylon fibers are characterized by resistance to abrasion and repeated deformation (bending).

Nylon fibers do not absorb moisture, therefore they do not lose strength when wet. But nylon fiber also has disadvantages. It is unstable to the action of acids; nylon macromolecules undergo hydrolysis at the site of the amide bonds. The heat resistance of nylon is also comparatively low. when heated, its strength decreases; at 2150C, melting occurs.

Products made of nylon, and in combination with nylon, have already become common in our life. Clothes are made of nylon threads, which are much cheaper than clothes made from natural materials. Fishing nets, fishing line, filter materials, cord fabric are made of nylon. Carcasses of auto and air tires are made of cord fabric. Tires with nylon cord are more wear-resistant than tires with rayon and cotton cord. Nylon resin is used to obtain plastics, from which various machine parts, gears, bearing shells, etc. are made. The Russian industry produces artificial fibers that are even more durable than nylon, for example, ultra-strong acetate silk, which surpasses steel wire in its strength. This silk can hold 126 kg per square millimeter, and steel wire 110 kg.

Lavsan

Lavsan (polyethylene terephthalate) representative of polyesters. It is a polycondensation product of the dihydric alcohol of ethylene glycol HO-CH2CH2-OH and the diacid terephthalic (1,4-benzenedicarboxylic) acid HOOC-C6H4-COOH (usually not terephthalic acid itself is used, but its dimethyl ester). The polymer belongs to linear polyesters and is obtained in the form of a resin. The presence of polar O-CO- groups regularly located along the macromolecule chain leads to intensification of intermolecular interactions, imparting rigidity to the polymer. Macromolecules in it are arranged randomly, in

Synthetic fibers began to be produced commercially in 1938. At the moment, there are already several dozen types of them. All of them have in common that the starting material is low molecular weight compounds that are converted into polymers through chemical synthesis. By dissolving or melting the obtained polymers, a spinning or spinning solution is prepared. They are molded from a solution or melt, and then they are finished.

Varieties

Depending on the features that characterize the structure of macromolecules, synthetic fibers are usually subdivided into hetero-chain and carbon-chain. The first include those obtained from polymers, in whose macromolecules, in addition to carbon, there are other elements - nitrogen, sulfur, oxygen and others. This includes polyester, polyurethane, polyamide and polyurea. Carbon-chain synthetic fibers are characterized by the fact that their main chain is built of carbon atoms. This group includes polyvinyl chloride, polyacrylonitrile, polyolefin, polyvinyl alcohol and fluorine.

Polymers serving as the basis for the production of heterochain fibers are obtained by polycondensation, and the product is molded from melts. Carbochains are obtained by chain polymerization, and the formation usually occurs from solutions, in rare cases from melts. You can consider any one synthetic polyamide fiber, which is called siblon.

Creation and application

A word like siblon is completely unfamiliar to many, but earlier on the labels of clothes one could see the abbreviation BBM, under which high-modulus viscose fiber was hidden. Then the manufacturers thought that such a name would look prettier than the siblon, which could be associated with nylon and nylon. The production of synthetic fibers of this type is carried out from a Christmas tree, no matter how fabulous it looks.

Peculiarities

The siblon appeared in the early 70s of the last century. It is an advanced viscose rayon. At the first stage, cellulose is obtained from wood; it is isolated in its pure form. The largest amount of it is contained in cotton - about 98%, but excellent threads are obtained from cotton fibers even without it. Therefore, wood is often used for the production of cellulose, in particular coniferous, where it contains 40-50%, and the rest is unnecessary components. They are required to be disposed of in synthetic fibers.

Process of creation

Synthetic fibers are produced in stages. At the first stage, the cooking process is carried out, during which all excess substances from the wood chips are transferred into the solution, and long polymer chains are also broken into separate fragments. Naturally, hot water is not enough here, additives of various reagents are made: natrons and others. Only cooking with the addition of sulfates produces pulp that is suitable for the production of siblon, since less impurities remain in it.

When the cellulose is already boiled down, it is sent for bleaching, drying and pressing, and then transferred to where it is needed - this is the production of paper, cellophane, cardboard and fibers, that is, what happens to it next?

Post-processing

If you want to get synthetic and then you first need to prepare a spinning solution. Cellulose is a solid that is not easy to dissolve. Therefore, it is usually converted into a water-soluble dithiocarbonate ester. The transformation process into this substance is rather long. First, the cellulose is treated with hot alkali, followed by squeezing, while unnecessary elements pass into the solution. After pressing, the mass is crushed, and then placed in special chambers, where pre-ripening begins - the cellulose molecules are shortened by almost half due to oxidative destruction. Further, the reaction of alkaline cellulose with carbon disulfide occurs, which makes it possible to obtain xanthate. It is a mass of orange color, similar to dough, an ester of dithiocarbonic acid and the original substance. This solution is called "viscose" for its viscosity.

Next, filtration takes place to remove the last impurities. Dissolved air is released by "boiling" the ether in a vacuum. All these operations lead to the fact that xanthate becomes similar to young honey - yellow and viscous. This completes the spinning dope.

Fiber production

The solution is forced through dies. the fibers are not simply spun in the traditional way. This operation is difficult to compare with a simple textile operation; it would be more correct to say that this is a chemical process that allows millions of streams of liquid viscose to become solid fibers. On the territory of Russia, viscose and siblon are obtained from cellulose. The second type of fiber is one and a half times stronger than the first, is characterized by greater resistance to alkalis, fabrics made from it are distinguished by hygroscopicity, a lower degree of shrinkage and creasing. And the differences in the production processes of viscose and siblon appear at the moment when newly "born" synthetic fibers appear in the precipitation bath after the spinnerets.

Chemistry to help

To obtain viscose, sulfuric acid is poured into the bath. It is designed to break down the ether, resulting in pure cellulosic fibers. If it is necessary to obtain a siblon, an ester that partially interferes with hydrolysis is added to the bath, therefore, residual xanthate will be contained in the threads. And what does it give? Further, the fibers are stretched and formed. When there are residues of xanthate in the polymer fibers, it turns out to stretch the polymer cellulose chains along the fiber axis, and not arrange them randomly, which is typical for ordinary viscose. After drawing, the rope of fibers is cut into spatulas 2-10 millimeters long. After several more procedures, the fibers are pressed into bales. A ton of wood is enough to produce 500 kilograms of pulp, from which 400 kilograms of siblon fiber will be produced. Spinning of cellulose takes about two days.

What's next with the siblon?

In the eighties, these synthetic fibers were used as additives to cotton to make the yarns spin better and not break. Siblon was used to make substrates for artificial leather, and it was also used in the production of asbestos products. Then the technologists were not interested in creating something new, as much fiber as possible was required to implement the plan.

And in the West, in those days, high-modulus viscose fibers were used to produce fabrics that were cheaper and stronger than cotton, but at the same time absorbed moisture well and breathed. Now Russia does not have its own cotton regions, so great hopes are pinned on the siblon. Only the demand for it is not yet particularly great, since now almost no one buys fabrics and clothes of domestic production.

Polymer fibers

They are usually subdivided into natural, synthetic and artificial. Natural fibers are those fibers, the formation of which is carried out in natural conditions. They are usually classified according to their origin, which determines their chemical composition, into animals and plants. The former are made up of protein, namely carotene. This is silk and wool. The latter are composed of cellulose, lignin and hemicellulose.

Artificial synthetic fibers are produced by chemical processing of naturally occurring polymers. It is customary to refer to them as acetate, viscose, alginate and protein fibers. Sulphate or sulphite wood pulp are used as raw materials for their production. Artificial fibers are produced in the form of textile and cord threads, as well as in the form of staple fibers, which are processed together with other fibers in the production of various fabrics.

Synthetic polyamide fiber is obtained from artificially derived polymers. As a raw material in this process, polymer fibers are used, formed from flexible macromolecules with a weakly branched or linear structure, having a significant mass - more than 15,000 atomic mass units, as well as a very narrow molecular weight distribution. Depending on the type, synthetic fibers are capable of having a high degree of strength, a significant value in relation to elongation, elasticity, resistance to multiple loads, low permanent deformations and fast recovery after removal of the load. That is why, in addition to being used in textiles, they were used as reinforcing elements during the manufacture of composites, and all this made it possible to make the special properties of synthetic fibers.

Conclusion

In the past few years, one can observe a very steady increase in the number of advances in the development of new polymer fibers, in particular, para-aramid, polyethylene, heat-resistant, combined, the structure of which is a core-shell, heterocyclic polymers, which include various particles, for example, silver or other metals. Now nylon is no longer the height of engineering, as now there is a huge amount of new fibers.