Synthetic fibers. Synthetic polyamide fiber
The 19th century was marked by important discoveries in science and technology. A sharp technical boom affected almost all areas of production; many processes were automated and moved to a qualitatively new level. The technical revolution did not bypass textile production - in 1890, for the first time in France, fiber made using chemical reactions. 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, but the processes for producing fabrics are not fundamentally different. Inorganic fibers include a group of mineral fibers that are obtained from inorganic raw materials.
Cellulose hydrate, cellulose acetate and protein polymers are used as raw materials for artificial fibers, and carbon-chain and heterochain polymers are used for synthetic fibers.
Due to the fact that chemical processes are used in the production of chemical fibers, the properties of the fibers, primarily mechanical, can be changed if different parameters of the production process are used.
Main distinctive properties chemical fibers, compared to natural ones, are:
- high strength;
- ability to stretch;
- tensile strength and long-term loads of varying 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 quite complex.
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 is assigned its own code in the catalog.
Technology for obtaining and producing chemical fibers
The production of chemical fibers has great benefits compared to natural fibers:
- firstly, their production does not depend on the season;
- secondly, the production process itself, although quite complex, is much less labor-intensive;
- thirdly, it is possible to obtain fiber with pre-established parameters.
From a technological point of view, these processes are complex and always consist of several stages. First, the raw material is obtained, then it is converted into a special spinning solution, then the formation of fibers and their finishing occurs.
Various techniques are used to form fibers:
- use of wet, dry or dry-wet solution;
- use of metal foil cutting;
- drawing from a melt or dispersion;
- drawing;
- flattening;
- gel molding.
Application of chemical fibers
Chemical fibers have very wide application in many industries. Their main advantage is their relatively low cost and long service life. Fabrics made from chemical fibers are actively used for sewing special clothing, in the automotive industry - to strengthen tires. In various types of technology, non-woven materials made of synthetic or mineral fiber are more often used.
Textile chemical fibers
As raw materials for the production of textile fibers of chemical origin (in particular, for the production of synthetic fiber), gaseous products of petroleum and coal. Thus, fibers are synthesized that 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 from spruce trees. Using chemical processes, this fiber can be given a visual similarity to natural silk, wool or cotton. Acetate fiber is made from waste from cotton production, so it absorbs moisture well.
Nonwovens made from chemical fibers
Nonwoven materials can be obtained from both natural and chemical fibers. Nonwoven materials are often produced from recycled materials and waste from other industries.
The fibrous base, prepared by mechanical, aerodynamic, hydraulic, electrostatic or fiber-forming methods, is bonded.
The main stage in the production of nonwoven materials is the bonding stage fibrous base obtained in one of the following ways:
- Chemical or adhesive (adhesive)- the formed web is impregnated, coated or irrigated with a binder component in the form of an aqueous solution, the application of which can be continuous or fragmented.
- Thermal- This method takes advantage of the thermoplastic properties of some synthetic fibers. Sometimes the fibers that make up the non-woven material, but in most cases, a small amount of fibers with a low melting point (bicomponent) is specially added to the nonwoven material at the molding stage.
Chemical fiber industry facilities
Since chemical production covers several areas of industry, all facilities chemical industry are divided into 5 classes depending on the raw material and application:
- organic matter;
- inorganic substances;
- organic synthesis materials;
- pure substances and chemicals;
- pharmaceutical and medical group.
By type of purpose, chemical fiber industry facilities are divided into main, general plant and auxiliary.
Synthetic fibers are chemical fibers formed from synthetic polymers obtained through polymerization or polycondensation reactions from low molecular weight compounds (monomers).
Synthetic fibers, compared to artificial ones, have high wear resistance, low creasing and shrinkage, -. but are characterized by low hygienic properties.
A new promising direction in the development of synthetic fibers is the development of technology for the production of ultra-thin
fibers (microfibers). It is with them that textile workers associate the possibility of producing comfortable fabrics and knitwear. The use of microfibers makes it possible to obtain materials with improved hygienic properties, fabrics that are soft, elastic, drapeable, waterproof, and have good hygienic properties.
Polyester fibers (polyethylene terephthalate - PET, lavsan, polyester)- synthetic fibers formed from complex heterochain polymers. Polyethylene terephthalate fibers are formed from a melt of polyester terephthalic acid and ethylene glycol.
In the global production of synthetic fibers, these fibers occupy first place. Lavsan fiber is characterized by crease resistance, which is superior in this indicator to all textile fibers, including wool. Thus, products made from lavsan fibers wrinkle 2-3 times less than wool products. In cellulose-based materials, to reduce their creasing, 45-55% lavsan fibers are added to the mixture.
Mylar fiber has very good resistance to light and weathering, second only to nitron fiber in this indicator. For this reason, it is advisable to use it in curtain-tulle, awning, and tent products. Mylar fiber is one of the heat-resistant fibers. It is thermoplastic, thanks to which the products retain the pleated and corrugated effects well. In terms of resistance to abrasion and bending, lavsan fiber is somewhat inferior to nylon fiber. The fiber has high strength, the breaking load of the fiber is 49-50 cN/tex, the thread - 29-39 cN/tex, and good deformability (relative elongation at break is 35^0 and 17-35%, respectively). The fiber is resistant to dilute acids and alkalis, but is destroyed when exposed to concentrated sulfuric acid and hot alkali. Dacron burns with a yellow, smoky flame, forming a black, indestructible ball at the end.
However, lavsan fiber has low hygroscopicity (up to 1%), poor dyeability, increased rigidity,
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electrification and pillability. Moreover, pills remain on the surface of products for a long time.
Polyamide fibers (nylon, dederon, nylon)- a type of synthetic fibers formed from a melt of polyamides - heterochain, polymers containing amide groups (- CO - MH 2) in the main chain and obtained by polymerization methods (for example, from e-caprolactam) or polycondensation dicarboxylic acids(or their esters) and diamines. The most widely used are nylon fibers formed from poly-e-caproamide, which is a product of the polymerization of e-caproamide.
The positive properties of nylon fiber include: high strength and deformation properties: the breaking load of the fiber is 32-35 cN/tex, the thread is 36-44 cN/tex and elongation at break is 60-70 and 20-45%, respectively, as well as the highest made of textile fibers, resistant to abrasion and bending. These valuable properties of nylon fiber are used when it is mixed with other fibers to obtain more wear-resistant materials.
Thus, the introduction of 5-10% nylon fiber into wool fabric increases its abrasion resistance by 1.5-2 times. Nylon fiber also has low creasing and shrinkage, and is resistant to microorganisms.
At a temperature of 170 °C, nylon softens, and at 210 °C it melts. When introduced into the flame, nylon melts, ignites with difficulty, and burns with a bluish flame. If the molten mass begins to drip, the combustion stops, a melted brown ball forms at the end, and the smell of sealing wax is felt.
However, nylon fiber is relatively low in hygroscopicity (3.5-4%), so the hygienic properties of products made from such fibers are low. In addition, nylon fiber has sufficient rigidity, is highly electrified, is unstable to light, alkalis, mineral acids, and has low heat resistance. On the surface of products made from nylon fibers, pills are formed, which, due to the high strength of the fibers, are retained in the product and do not disappear during wear.
Polyacrylonitrile fibers (PAN, acrylic, nitron, or-lon, curtel)- synthetic fibers obtained from polyacrylonitrile or copolymers containing more than 85% acrylonitrile. Paul and acrylic nitrile are obtained by radical polymerization of acrylonitrile. Fibers made from copolymers containing 40-85% acrylonitrile are usually called modacrylic.
Nitron - the softest, silkiest and warmest synthetic fiber. It surpasses wool in heat-protective properties, but is inferior even to cotton in terms of abrasion resistance. The strength of nitron is half that of nylon, and its hygroscopicity is very low (1.5%). Nitron is acid-resistant, resistant to all organic solvents and microorganisms, but is destroyed by alkalis.
Has low creasing and shrinkage. It is superior to all textile fibers in light resistance. At a temperature of 200-250 °C, nitron softens. Nitron burns with a yellow, smoky flame with flashes, forming a solid ball at the end.
The fiber is fragile, does not dye well, is highly electrified and pilled, but pills, due to their low strength properties, disappear during wear.
To eliminate the shortcomings - low hygroscopicity and poor dyeability, a wide range of modified PAN fibers - modacrylic fibers - has been created.
Polyvinyl chloride fibers. Produced from polyvinyl chloride - PVC fiber and from perchlorovinyl - chlorine. The fibers are highly chemical resistance, low thermal conductivity, very low hygroscopicity (0.1-0.15%), the ability to accumulate electrostatic charges during friction against human skin, which have a therapeutic effect for joint diseases. The disadvantages are low heat resistance (products can be used at temperatures no higher than 70 ° C) and instability to light and weather conditions.
Polyvinyl alcohol fibers (vinol) obtained from polyvinyl alcohol. Vinol has average hygroscopicity (5%), the degree of swelling in water is 150-200%, and has high stability.
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resistance to abrasion, second only to polyamide fibers, and dyes well.
Polyolefin fibers obtained from melts of polyethylene and polypropylene. These are the lightest textile fibers, products made from them do not sink in water. They are resistant to abrasion, chemical agents, and have high tensile strength. The disadvantages are low light fastness and low heat resistance.
Polyurethane fibers (spandex, lycra, elastin) belong to elastomers, because they have exceptionally high elasticity (extensibility up to 800%). They are light, soft, resistant to light, washing, and sweat. Disadvantages include low hygroscopicity (1-1.5%), low strength, low heat resistance.
In table 2.1 shows the symbols of types of textile fibers.
Table 2.1Symbols for types of textile fibers
| Symbol | Decoding | ||
| Russia | UK | Germany | |
| ^O | Wool | Shoo! | Nooo!e |
| ShR | Alpaca | A1race | A1cancer |
| \YL | Lama | Eat | bate |
| \UK | Camel hair | Sate! | Kate! |
| Ш8 | Cashmere | Casbette | Kazsbggpge |
| ^M | Mohair | Moba1r | Mopa1g |
| T | Angora | Ap§oga | Ap§oga |
| \US | Vigunya | Uyuipa | Uishgua |
| That | Guanaco | Oiapaso | Siapabe |
| 8E | Silk | 81Ш | Zen|e |
| CO | Cotton | Soyop | Wait\uoo1e |
| 1l | Flax | btep | btane |
| Sh | Jute | Meh | 1i1e |
End of table. 2.1
Synthetic fibers include polyamide, polyester, polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol, polypropylene, etc.
Polyamide fibers(nylon, anide, enanth). The fibers are cylindrical in shape, their cross section depends on the shape of the die hole through which the polymers are pressed (Fig. 9, A).
Polyamide fibers are distinguished by high tensile strength (40-70 cN/tex), resistant to abrasion, repeated bending, have high chemical resistance, frost resistance, and resistance to microorganisms. Their main disadvantages are low hygroscopicity (3.5-5%) and light resistance, high electrification and low heat resistance; when heated to 160°C, their strength decreases by almost 50%. As a result of rapid “aging”, they turn yellow in the light, become brittle and hard. The fibers burn with a bluish flame, forming a brown solid ball at the end.
Polyamide fibers and threads are widely used in the production of hosiery and knitwear, sewing threads, haberdashery products (braids, ribbons), lace, ropes, fishing nets, conveyor belts, cord, technical fabrics, as well as in the production of household fabrics in mixtures with other fibers and threads. Adding 10–20% polyamide staple fibers to natural ones dramatically increases the wear resistance of products.
Polyester fibers(lavsan, terylene, dacron). In cross section, lavsan has the shape of a circle (Fig. 9, b The tensile strength of lavsan is slightly lower than that of polyamide fibers (40-50 cN/tex), the elongation at break is within 20-25%, and strength is not lost when wet. Unlike nylon, lavsan is destroyed when exposed to acids and alkalis; its hygroscopicity is lower than nylon (0.4%). When brought into the flame, lavsan melts and slowly burns with a yellow, smoky flame. The fiber is heat-resistant, has low thermal conductivity and high elasticity, which makes it possible to obtain products from it that retain their shape well; have low shrinkage. The disadvantages of the fiber are its increased rigidity, the ability to form pilling on the surface of products and strong electrification.
Lavsan is widely used in the production of household fabrics in a mixture with wool, cotton, linen and viscose fiber, which gives the products increased abrasion resistance and elasticity
Rice. 9. Longitudinal view and cross section of synthetic fibers:
a) nylon; b) lavsan; c) nitron; d) chlorine
and crease resistance. It is also successfully used in the production of non-woven fabrics, sewing threads, curtains and tulle products, technical fabrics and cord. Complex lavsan threads are subjected to texturing, as a result of which they better absorb moisture and retain heat.
Polyacrylonitrile fibers (nitron, orlon). In appearance, nitron resembles wool. Its surface is smooth (Fig. 9, V) with an irregular cross-sectional shape with jagged edges (dumbbell-shaped and close to it).
Nitron is distinguished by high strength (32-39cN/tex), which does not change when wet, and elasticity. Products made from it retain their shape quite well after washing. Nitron is not damaged by moths and microorganisms and is highly resistant to nuclear radiation. In terms of abrasion resistance, nitron is inferior to polyamide and polyester fibers. In addition, it is characterized by low hygroscopicity (1.5%), which limits its use in the production of linen fabrics with strong electrification. Nitron fiber also has the best light resistance, low thermal conductivity, that is, good heat-shielding properties and is therefore often used in mixtures with wool and in pure form for suit and coat materials.
Nitron burns in flashes, emitting a haze of black soot. After combustion ends, a dark, easily crushed lump is formed. Nitron is used in the production of outer knitwear, dress fabrics, as well as fur on a knitted and fabric base, carpets, blankets and fabrics for technical purposes.
Polyvinyl chloride fibers(chlorine) (Fig. 9, G). Compared to other synthetic fibers and cotton, it is less durable (12-14 cN/tex), less elastic, less abrasion resistant, has low hygroscopicity (0.1%), low resistance to light weather, low heat resistance (70 °C). It is characterized by high chemical resistance, nonflammability, and nonflammability.
Chlorine, when brought to a flame, chars, but does not burn, releasing the smell of chlorine.
Chlorine has the ability to accumulate electrostatic charges, which is why it is used to make medicinal underwear. Chlorine is also used in the manufacture of fabrics for workwear, as it is resistant to water and microorganisms.
PVC fiber, like chlorine, belongs to polyvinyl chloride fibers, but unlike chlorine it is the strongest (26-36cN/tex), more elastic and light-resistant. It is used in the production of knitted and curtain-tulle products, blankets, decorative fabrics, batting, carpets, rugs, rugs and other products.
Polyvinyl alcohol fibers and threads. The threads are formed from a solution using the wet method. Moreover, depending on the spinning conditions and subsequent acetylation, threads with to varying degrees strength and water resistance: from water-soluble to hydrophobic.
Insoluble polyvinyl alcohol fibers produced in our country are called vinol. They have many positive properties: strength, high resistance to abrasion, light weather, chemical reagents, and repeated deformation. Vinol is quite elastic and characterized by high heat resistance. The temperature of softening and the beginning of fiber decomposition is 220°C. Vinol burns with a yellowish flame; after the burning stops, a solid lump of light brown color is formed.
A distinctive feature of polyvinyl alcohol fibers, which sets them apart from all synthetic fibers, is their high hygroscopicity, due to the presence of a large number of hydroxyl groups in the polymer macromolecules. In terms of hygroscopicity, polyvinyl alcohol fibers are close to cotton, which makes it possible to use it in the production of materials for underwear and costume and dress products. These fibers are easily dyed with cellulose fiber dyes. They are used in a mixture with cotton and wool for the production of fabrics, knitwear, carpets, etc.
A water-soluble variety of polyvinyl alcohol fibers is used in the textile industry as an auxiliary (removable) fiber in the production of openwork products, thin fabrics, materials with porous fibrous structures, as well as in the production of guipure (instead of natural silk). Polyvinyl alcohol threads are used in medicine for temporary fastening of surgical sutures.
The presence of hydroxyl groups allows for chemical modification of these fibers, especially by the synthesis of graft copolymers, due to which it is possible to create fibers and threads with specific properties: fire-resistant, bactericidal, ion-exchange, etc.
Polyolefin fibers and threads. From the group of polyolefins, polypropylene is used for the production of fibers [– CH 2 –SNSN 3 –] n and polyethylene [– CH 2 –CH 2 –] n medium and low pressure.
Polyolefin fibers can be spun from polymer melts or solutions, followed by drawing and heat setting.
Polypropylene and polyethylene threads have fairly high strength and tensile elongation values. Polyolefin fibers and threads are characterized by high resistance to acids and alkalis, and are not inferior in terms of chemical resistance to chlorine. Their resistance to abrasion is lower than that of polyamide threads, especially polypropylene.
The heat resistance of polyolefin threads is low. At a temperature of 80°C, polyethylene thread loses about 80% of its original strength. The hygroscopicity of the threads is almost zero, so dyeing them is possible only with the introduction of pigment into the polymer before molding. Low hygroscopicity is also associated with significant electrification of these threads. The density of polyethylene and polypropylene threads is very low, so products made from them do not sink in water.
Polyolefin fibers are used mainly for technical purposes, as well as in a mixture with hydrophilic fibers (cotton, wool, viscose, etc.) in the production of materials for outerwear, shoes, decorative fabrics.
Polyurethane threads. There are currently enough large assortment materials using polyurethane (elastane) threads (spandex, lycra, etc.). The threads are cylindrical in shape with a round cross section, amorphous. A feature of all polyurethane threads is their high elasticity: their elongation at break is 800%, the proportion of elastic and elastic deformation is 92-98%. Therefore, materials containing polyurethane threads have good elastic properties and wrinkle little. It was this feature that determined the area of their use. Spandex is used mainly in the manufacture of elastic products. These threads are used to produce fabrics and knitted fabrics for household use, for sportswear, as well as hosiery. Polyurethane threads have insufficient strength (6–7 cN/tex) and heat resistance. When exposed to temperatures above 100°C, threads lose their elastic properties. Therefore, they are produced mainly with a braid that protects them. Polyurethane threads also have very low hygroscopicity (0.8–0.9%), which also limits their use in pure form.
To specifically change the properties of chemical fibers, they are chemically modified. in various ways. In order to expand the use of chemical fibers and threads in various fields of technology, high-strength, high-modulus (low-stretch), heat-resistant, non-flammable, light-resistant and other types of fibers with special properties have been created. Thus, by introducing aromatic units (benzene rings) into the chain polyamide molecule, high-strength and heat-resistant fibers such as phenylon, vnivlon (or SHM - ultra-high modulus), oxalone, arimid T, Kevlar, etc. were obtained. By special processing of polyacrylonitrile and viscose fibers, high-strength, chemical-resistant, heat-resistant fibers were obtained carbon They have unique properties. Under conditions of prolonged heating (at temperatures of 400°C or more) they retain their mechanical properties and are non-flammable. Used in various fields of technology (cosmonautics, aviation and chemical engineering, etc.)
More detailed information about the production and structure of chemical fibers is given in the textbook.
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Some natural cellulose fibers are processed and processed for specific purposes. Well-known fibers such as viscose, acetate, etc. are obtained by processing various natural polymers.
The first man-made fibers that were developed and manufactured used polymers of natural origin, more precisely cellulose, which is a raw material available in large quantities in flora.
Cellulose is a natural polymer that makes up the living cells of all vegetation. It is the material at the center of the carbon cycle and the most abundant and renewable biopolymer on the planet.
Cotton sheets and wood pulp, rayon, copper-ammonia silk, cellulose acetate (recycled and triacetate), polynose, high wet modulus (HVM) fiber.
- Cellulose is one of many polymers found in nature.
- Wood, paper and cotton contain cellulose. Cellulose is an excellent fiber.
- Cellulose is made up of repeating units of monomeric glucose.
- The three types of regenerated cellulose fibers are rayon, acetate and triacetate, which are derived from cell walls short cotton fibers called linters.
- Paper, for example, is almost pure cellulose
Viscose
Originally, the word "viscose" was applied to any fiber made from cellulose and therefore containing cellulose acetate fibers. However, the definition of viscose was described in 1951 and now includes textile fibers and fibers consisting of regenerated cellulose, excluding acetate.
- Viscose is a regenerated cellulose fiber.
- This is the first man-made fiber.
- It has a jagged circular shape with a smooth surface.
- When wet, viscose loses 30-50% of its strength.
- Viscose is formed from natural polymers and is therefore not a synthetic fiber, but a man-made regenerated cellulose fiber.
- The fiber is sold as rayon.
- There are two main types of viscose fiber, namely viscose and copper-ammonia.
Acetate
A derived fiber in which the fiber-forming substance is cellulose acetate. Acetate is produced from cellulose by the reaction of refining wood pulp with acetic acid and acetic anhydride in the presence of sulfuric acid.
Characteristics of acetate fiber:
- Luxurious feel and appearance
- Wide range of colors and glosses
- Excellent drape and softness
- Relatively fast drying
- Resistant to shrinkage, moths and powdery mildew
Special dyes have been developed for acetate because it does not accept the dyes typically used on cotton and rayon.
Acetate fibers are manufactured fibers in which the fiber-forming substance is cellulose acetate. The cellulose ethers triacetate and acetate are formed by the acetylation of cotton linters or wood cellulose using acetic anhydride and an acid catalyst in acetic acid.
Acetate and triacetate fibers are very similar in appearance to permanent tenacity rayon. Elements and triacetates are moderately stiff fibers and have good flexural and deformation elasticity, especially after heat treatment.
The abrasion resistance of acetate and triacetate is poor, and these fibers cannot be used in applications requiring high abrasion and wear resistance; however, the abrasion resistance of these fibers is excellent. Although acetate and triacetate are moderately absorbent, their absorption cannot match that of pure cellulose fibers. Acetate fabrics feel slightly softer and more flexible than triacetate. The fabrics of both fibers have excellent characteristics drapery. Acetate and triacetate fabrics have a pleasing appearance and a high degree of shine, but the sheen of these fabrics can be modified by adding a matting agent.
Both acetate and triacetate are susceptible to attack by a number of household chemicals. Acetate and triacetate are exposed to strong acids and bases and oxidizing bleaches. Acetate has only slight resistance to sunlight, whereas the solar resistance of triacetate is higher. Both fibers have good heat resistance below their melting points.
Acetate and triacetate cannot be dyed with the dyes used for cellulose fibers. These fibers can be satisfactorily dyed with disperse dyes at moderate to high temperatures to produce crisp, vibrant shades. Acetate and triacetate dry quickly and can be dry cleaned.
Synthetic fibers have a number of properties that natural fibers do not have: high mechanical strength, elasticity, resistance to action chemicals, 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.
– The negative properties of synthetic fibers are reduced hygroscopicity, low breathability, high electrification when worn, therefore it is not recommended to wear clothes made from these fabrics for children and people with increased sensitivity to synthetic fibers.
The most common synthetic fibers are:
Polyester fibers (polyester, lavsan, crimplen, 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, 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
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Properties of artificial fibers