Table of fibers. Fiber. Formula. Properties. Application. Cotton (cotton fabric). Wool. -----------. Natural silk. -----------. Viscose. Acetate. Lavsan. Kapron. (CH6H10O5)n. (C6H10O5)n. OCOCH3 (C6H7)---- OCOCH3 OCOCH3. (-C-C6H4-C-CH2-CH2-O-)n. (-N-(CH2)5-C-)n. It is hygienic, has high strength, resistance to abrasion, washing, exposure to light, but does not have the necessary elasticity, i.e. it stretches and wrinkles a lot. Resistant to acids and alkalis. Manufacturing different kind clothes, towels, handkerchiefs, upholstery fabrics, curtains, as well as gauze, technical fabrics for various purposes, container and packaging fabrics, summer blankets, bedspreads and tablecloths. It has the properties of crimp, length, strength, extensibility, elasticity, rigidity, plasticity, elasticity, hygroscopicity, color, gloss. Not resistant to acids and alkalis. Production of various fabrics, knitwear, carpets, felt products, high-quality beaver, blankets, blankets. It has the properties of high hygroscopicity, easy make-up, pleasant moderate gloss. It has good mechanical properties. Not very resistant to alkalis, more resistant to mineral acids and organic solvents. To the action of light, the resistance of silk is low. Manufacture of dresses, shirts, linings, raincoats, suits, coats, ties, women's clothing, haberdashery, as well as scarves, tablecloths and bedspreads. High hygiene, hygroscopicity. High loss of wet strength, easy creasing, poor friction resistance and low modulus of elasticity, especially when wet. Not resistant to alkalis and acids, more resistant to organic solvents. Production of silk and staple fabrics, knitwear, fabrics for various purposes from mixtures of viscose fiber with cotton or wool, as well as other chemical fibers. High elasticity (low wrinkling), pleasant to the touch, soft, transparent to ultraviolet rays; tensile strength is low, thermal stability is low, abrasion resistance is low, and electrified is high. The fiber is not very resistant to the action of even dilute solutions of alkalis and acids; soluble in some organic solvents. Manufacture of consumer goods (outerwear, ladies' underwear, lining and dress fabrics). Acetate staple fiber is used to make fine cloths and some knitwear. High temperature resistance. It dissolves in phenols, partially (with destruction) in concentrated sulfuric and nitric acids; completely destroyed by boiling in concentrated alkalis. Resistant to acetone, carbon tetrachloride, dichloroethane and other solvents, microorganisms, moths, mold, carpet bugs. Low resistance to abrasion and resistance to repeated bending, higher impact strength. Strong electrification, tendency to pilling, rigidity of products. It is used in the manufacture of conveyor belts, drive belts, ropes, ropes, sails, fishing nets and trawls, petrol and oil resistant hoses, electrical insulating and filtered materials, as a tire cord. Used in medicine. Textile thread is used for the manufacture of knitwear, fabrics such as taffeta, crepes, etc. In pure or mixed form used for the manufacture of artificial fur, carpets. It has the properties of high temperature resistance, high tensile strength, excellent abrasion and impact resistance. Resistant to the action of many chemicals, well resists biochemical influences, stained with many dyes. It dissolves in concentrated mineral acids, phenol, cresol, trichloroethane, etc. It is poorly resistant to light, especially ultraviolet rays. Strongly electrified. It is used in the production of consumer goods, tire cord, rubber products, filter materials, fishing nets, bristles, ropes, etc. Textured (high-volume) nylon threads are widely used.

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fabrics

"Properties of chemical fibers" - World consumption of the main types of textile fibers (in million tons). According to the dry method, fibers are formed from cellulose acetate, copolymers of polyacrylonitrile and polyvinyl chloride. Classification of synthetic fibers from synthetic high molecular weight organic compounds. Stages of forming chemical fibers.

"Synthetic fiber" - In the production of fibers, there can be up to 40,000 holes in the spinneret. The jets flowing from the spinnerets solidify to form filaments. Raw materials for artificial fibers are obtained by isolation from substances formed in nature. Stretching and heat treatment of fibers. After stretching, the threads are heat-fixed.

"Types of fabrics" - The color of the skin can be natural and dyed. Faux fur is made on a knitted or woven basis. Warming materials. Ribbons: satin, jacquard, nylon, decorative. mechanical way. Knitting-stitching method. Interlining materials serve to stiffen the parts of a garment.

"Features of fabrics" - Defects of yarn. Research work. Plain weave. Fabric sizes. Geometric properties. The ability of a fabric to change moisture resistance. Penetration depends on the density of the fabric. Shine. Slip. Breathability. The ability to form. Round pleats. The ability to stretch the fabric under the iron.

1. Table of fibers;

• 1. Table of fibers;

• 2. Chemical fibers;

• 3. The concept of the technology of manufacturing chemical fibers;

• 4. Natural fibers;

• 5. Vegetable fibers;

• 6. Animal fibers;

• 7. Fibers of mineral origin;

• 8. Synthetic fibers;

• 9. Polyamide fibers;

• 10. Polyester fibers.

• Chemical fibers are divided into artificial and synthetic. Artificial fibers are made from natural macromolecular compounds, mainly from cellulose. Synthetic fibers are made from synthetic high molecular weight compounds.

Man-made fibers are made in the form of an endless thread, consisting of many individual fibers or a single fiber, or in the form of staple fiber - short pieces (staples) of untwisted fiber, the length of which corresponds to the length of a wool or cotton fiber. Staple fiber, like wool or cotton, serves as an intermediate for yarn production. Before spinning, the staple fiber can be mixed with wool or cotton.

• The first stage of the production process of any chemical fiber is the preparation of a spinning mass, which, depending on the physicochemical properties of the initial polymer, is obtained by dissolving it in a suitable solvent or transferring it to a molten state.

The resulting viscous liquid is thoroughly purified by repeated filtration and solid particles and air bubbles are removed. If necessary, the solution (or melt) is additionally processed - dyes are added, subjected to “ripening” (standing), etc. If atmospheric oxygen can oxidize a high molecular weight substance, then “ripening” is carried out in an inert gas atmosphere.

The second stage is the formation of the fiber. For formation, a solution or polymer melt is fed into a so-called spinneret using a special dosing device. The spinneret is a small vessel made of durable heat-resistant and chemically resistant material with a flat bottom, having big number(up to 25 thousand) small holes, the diameter of which can vary from 0.04 to 1.0 mm.

When forming a fiber from a polymer melt, thin streams of melt from the holes of the spinneret enter the space where they cool and solidify. If the fiber is formed from a polymer solution, then two methods can be applied: dry formation, when thin streams enter a heated shaft, where, under the action of circulating warm air, the solvent escapes and the streams harden into fibers; wet formation, when the streams of the polymer solution from the spinneret fall into the so-called precipitation bath, in which, under the action of various chemicals contained in it, the streams of the polymer harden into fibers.

In all cases, fiber formation is carried out under tension. This is done in order to orient (arrange) the linear molecules of a macromolecular substance along the axis of the fiber. If this is not done, then the fiber will be significantly less durable. To increase the strength of the fiber, it is usually further stretched after it has partially or completely solidified.

• After formation, the fibers are collected into bundles or bundles, consisting of many fine fibers. The resulting threads are washed, subjected to special treatment - soaping or oiling (to facilitate textile processing) or dried. Finished threads are wound on spools or spools.

• In the production of staple fibers, the filaments are cut into pieces (staples). Staple fiber is collected in bales.

Natural fibers are natural textile fibers that are formed under natural conditions, strong and flexible bodies of small transverse dimensions and limited length, suitable for the manufacture of yarn or directly textile products (for example, non-woven). Single fibers that do not divide in the longitudinal direction without destruction are called elementary (long fibers are called elementary filaments); several fibers, longitudinally fastened (for example, glued) together, are called technical. By origin, which determines the chemical composition of the fibers, there are fibers of plant, animal and mineral origin.

• Vegetable fibers form on the surface of seeds

• (cotton), in plant stems (thin stem fibers - flax, ramie; coarse

- jute, hemp hemp, kenaf, etc.) and in leaves (hard leaf fibers, for example, manila hemp (abaca), sisal). The common name for stem and leaf fibers is bast. Plant fibers are single cells with a channel in the central part. During their formation, first, the outer layer (primary wall) is formed, inside which several dozen layers of synthesized cellulose are gradually deposited.

• (secondary wall). This structure of the fibers determines the features of their properties - relatively high strength, low elongation, significant moisture capacity, as well as good dyeability due to high porosity (30% or more).

• The most important textile fiber is cotton. Yarn from this fiber is used

• (sometimes mixed with other natural or chemical fibers) for the production of household and technical fabrics, knitwear

• (mainly linen and hosiery), curtain-tulle products, ropes, ropes, sewing threads, etc. Non-woven and wadded products are made directly from cotton fiber.

• Bast fibers are isolated from plants mainly in the form of technical fibers.

• Coarse-stemmed fibers are processed into thick yarn for bag and container fabrics, as well as for ropes, ropes, twine.

Animal fibers include wool and silk. Wool - hair fibers of sheep (almost 97% of the total wool production), goats, camels and other animals. The following types of fibers are found in wool: 1) fluff - the thinnest and most elastic fiber with an inner ("cortical") layer, composed of spindle-shaped cells, and an outer scaly layer; 2) awn - a thicker fiber, which also has a loose core layer, which consists of sparsely spaced plates perpendicular to the fiber axis; 3) transitional hair, in which the core layer is discontinuously located along the length of the fiber (occupies an intermediate value in thickness between down and awn); 4) "dead" hair - coarse, very thick, hard and brittle fiber with a highly developed core layer. Sheep wool, consisting of fibers of the first or second type, is called homogeneous, consisting of fibers of all types - heterogeneous.

• Wool fiber is characterized by low strength, high elasticity and hygroscopicity, low thermal conductivity. It is processed (in its pure form or mixed with chemical fibers) into yarn, from which fabrics, knitwear, as well as filters, gaskets, etc. are made.

• Silk is a product of the excretion of the silk-secreting glands of insects, of which the silkworm has the main industrial importance.

The fibers of mineral origin include asbestos (the most widely used is chrysolite-asbestos), which are split into technical fibers. They are processed (usually in a mixture with 15-20% cotton or chemical fibers) into yarn, from which fire-retardant and chemical-resistant fabrics, filters, etc. are made. Non-spun short asbestos fiber is used in the production of composites (asboplastics), cardboards, etc.

• Synthetic fibers include: polyamide, polyacrylonitrile, polyester, perchlorovinyl, polyolefin fibers.

• Polyamide fibers, in many respects superior in quality to all natural and artificial fibers, are gaining more and more recognition. The most common polyamide fibers produced by the industry include capron and nylon. Relatively recently, the enant polyamide fiber has been obtained.

• Kapron is a polyamide fiber obtained from polycaproamide, which is formed during the polymerization of caprolactam (lactam aminocaproic acid):

• The original caprolactam is practically obtained in two ways:

• 1. From phenol:

• Further, the oxime of cyclohexane in an acid medium (oleum) undergoes the Beckmann rearrangement, which is characteristic of the oximes of many ketones. As a result of such a rearrangement, the carbon-carbon bond is broken and the cycle is expanded; while the nitrogen atom enters the cycle:

• 2. From benzene:

• The oxidation of cyclohexane is carried out with air oxygen in the liquid phase at 130-

• 140oC and 15-20 kgf/cm2 in the presence of a catalyst – manganese stearate.

• In this case, cyclohexanone and cyclohexanol are formed in a ratio of 1:1.

• Cyclohexanol degenerates to cyclohexanone, and the latter is converted to caprotam in the manner described above.

• During the construction of new and expansion of existing caprolactam production facilities, the second scheme for its production will be used mainly. In this case, the oxidation of cyclohexanone with air will be intensified by increasing the reaction temperature to 190-2000C, which will significantly reduce the reaction time.

• The polymerization of caprolactam is carried out at those factories that produce synthetic fiber. Caprolactam is melted before polymerization. To prevent the oxidation of lactam, the polymerization process proceeds at 15-16 kgf/cm2 at a temperature of about 2600C, and is carried out in a nitrogen atmosphere.

• The polymer formed as a result of the polymerization of caprolactam solidifies into a white horn-like mass, which is then crushed and treated with water at an elevated temperature to grind the unreacted monomer and the resulting dimers and trimers.

To form a nylon fiber, the dried polymer is loaded into closed steel apparatus equipped with grates, on which it is melted at 260-2700C in a nitrogen atmosphere. The pressure-filtered alloy enters the die. The fibers formed after leaving the spinneret are cooled in the shaft and wound on bobbins. Immediately from the bobbins, a bundle of fibers is sent to the hood, twisting, washing and drying.

• Capron fiber in appearance resembles natural silk; in terms of strength, it significantly exceeds it, but is somewhat less hygroscopic. This fiber is widely used for the manufacture of high-strength cord, fabrics, hosiery and knitwear, ropes, nets, etc.

• Nylon fiber (anid). It is obtained from polyamide, a polycondensation product of the so-called AG salt (hexamethylenediamine adipate).

• Salt AG is obtained by the interaction of adipic acid with hexamethylenediamine in methanol:

• Polycondensation is carried out in an autoclave at 275-2800C in a nitrogen atmosphere:

• The polyamide obtained as a result of the polycondensation of the AG salt is forced in molten form through an alkaline hole into a bath of cold water. The solidified resin is dried, crushed, melted, and a fiber is formed from the melt.

• Recently, Russian chemists have created a new polyamide fiber enant, which is distinguished by elasticity, light resistance and strength.

• Enanth is obtained by polycondensation of α-aminoenanthic acid. Technological processes for producing nylon and enanth fibers are similar to each other.

• Of the polyester fibers, the most important is lavsan fiber, produced in various countries under the name "terylene", "dacron", etc.

• Lavsan is a synthetic fiber obtained from polyethylene terephthalate.

• The feedstock for the production of polyethylene terephthalate is dimethyl terephthalate (dimethyl ester of terephthalic acid) or terephthalic acid.

• The dimethyl terephthalate is first heated at 170-280°C, with an excess of ethylene glycol. In this case, transesterification occurs and diethylol terephthalate is obtained:

• Diethylol terephthalate undergoes polycondensation in vacuum (residual pressure 1-3 mmHg) at 275-280oC in the presence of catalysts (alkali metal alcoholates, PbO, etc.):

• The use of dimethyl terephthalate rather than free terephthalic acid for the production of polyester is explained by the fact that the purity of terephthalic acid is of decisive importance for the last polycondensation reaction.

• Since obtaining pure acid is a very difficult task, all previously developed technological processes for obtaining lavsan were based on the use of dimethyl terephthalate as the initial monomer.

• Currently, the largest foreign firms use not dimethyl terephthalate, but highly purified terephthalic acid as the starting monomer, which makes it possible to exclude the cumbersome stage of transesterification from the technological process and, in connection with this, significantly reduce the cost of the entire technological process.

• The resulting polyester is poured from the reactor in the form of a ribbon into a spinning bath with water or a drum, where it solidifies. Then it is crushed, dried and formed on machines similar to those used in the production of capron.

• Lavsan fiber is very strong, resilient, heat and light resistant, resistant to weathering, chemicals and abrasion. Being similar in appearance and a number of properties to wool, it surpasses it in wear and is much less wrinkled.

• Lavsan fiber is added to wool for the manufacture of high-quality fabrics and knitwear that do not wrinkle. Lavsan is also used for conveyor belts, belts, sails, curtains, etc.

Depending on the origin, textile fibers are divided into natural and chemical (Fig. 1).

Natural fibers include fibers created by nature itself, without human intervention. They can be of vegetable, animal or mineral origin.

Natural fibers of plant origin are obtained from the surface of seeds (cotton), from stems (flax, hemp, etc.), from leaves (sisal, etc.), from fruit shells (coir).

Natural fibers of animal origin are represented by wool fibers of various animals and cocoon silk of mulberry and oak silkworm.

The listed natural fibers consist of substances that belong to natural polymers. These are cellulose in plant fibers and proteins in animal fibers.

Chemical fibers are divided into artificial and synthetic.

Artificial fibers are obtained by chemical processing of natural polymers of plant and animal origin, from pulp production and food industry waste. The raw materials for them are wood, seeds, milk, etc. Most widely used in the garment industry textile materials based on artificial cellulose fibers, such as viscose, polynose, copper-ammonia, triacetate, acetate.

Synthetic fibers are obtained by chemical synthesis of polymers, i.e. creating substances with a complex molecular structure from simpler ones, most often from products of oil and coal processing. These are polyamide, polyester, polyurethane fibers, as well as polyacrylonitrile (PAN), polyvinyl chloride (PVC), polyvinyl alcohol, polyolefin.

Fiber classification

1. The main properties of fibers and their dimensional characteristics:

NATURAL FIBERS

A. Natural fibers of plant origin

cotton fiber

Cotton is the name given to the fibers that cover the seeds of the annual cotton plant. Cotton is a heat-loving plant that consumes a large amount of moisture. Grows in hot areas.

Many types of cotton are known, but mainly two types are of industrial importance: medium-fiber and fine-fiber.

Medium-fiber cotton ripens in 130-140 days from the moment of sowing, gives a fiber 25-35 mm long.

Fine-staple cotton has a longer maturation period, lower yields, but gives a longer (35-45 mm), thin and strong fiber, which is used to produce high-quality yarn.

Line Density cotton fibers ranges from 0.17-0.2 tex.

In the first two months, a cotton bush is formed, then, after a short flowering, the development of its fruit-boxes begins. Inside the developing boxes, seeds are formed, on the surface of which fibers appear - thin-walled tubes. First, the fibers grow in length, and in the last month they mature - a gradual layer-by-layer deposition of cellulose on the walls of the fibers. The ripening of the boxes occurs sequentially, starting from the lower branches of the bush. Therefore, cotton is harvested in several steps: first, the lower bolls are harvested, and then those growing higher.

The fibers on the seeds at the end of the ripening period take the form of twisted (crimped) flattened ribbons with walls of a certain thickness and a channel inside. The wall thickness and the degree of crimp characterize the maturity of the fiber, which in turn determines its quality. According to the degree of maturity, cotton fibers are divided into 11 groups. On fig. 2 gives examples of standards used to assess the maturity of cotton by the comparative method.

Immature thin-walled fibers have low strength, low elasticity and are poorly dyed. They are not suitable for textile production.

Overripe fibers have thick walls, increased strength, but their rigidity increases significantly. These fibers are also not suitable for textile processing.

Under the microscope, immature fibers are flat, ribbon-like with thin walls and a wide channel inside (see Fig. 2c). As the fiber matures, the fiber wall thickness increases and the channel becomes narrow. Mature fibers are flattened tubules with characteristic helical tortuosity and a channel running inside the fiber (see Fig. 2b). Overripe fibers have a cylindrical shape, thick walls and a narrow channel (see Fig. 2, a).

Mature cotton fiber contains more than 95% cellulose, the rest is related substances.

The degree of maturity of cotton fibers affects their strength and elongation. The proportion of plastic deformation in the full elongation of the mature cotton fiber is 50%, so cotton fabrics are strongly wrinkled.

Under the influence of light weather, cotton, like all organic fibers, loses its strength.

With a significant increase in temperature, dry fibers lose strength, a slight yellowness appears on them, followed by darkening, and at a temperature of 250 ° C, the fibers are charred. Cotton fibers burn with a yellow flame, producing a gray ash and smelling of burnt paper.

Cotton fiber is processed into yarn, from which fabrics, knitted and non-woven fabrics are made, sewing thread and others. Fine-fibered cotton is processed into fine and smooth combed yarn, intended for the thinnest and highest quality fabrics - batiste, voile. Medium-staple cotton is intended for fluffy yarn of medium thickness, from which chintz, calico, and satin are produced. From cotton fluff (short fibers unsuitable for spinning), cellulose ethers are used to produce artificial fibers (acetate, triacetate), as well as cellulose for the production of films, plastics, etc. In addition, fibers unsuitable for spinning production are used for the production of non-woven fabrics.

Flax fibers belong to the so-called bast fibers, i.e. fibers obtained from plant stems. Flax fibers are the most valuable of all bast fibers due to their high strength, flexibility and good sorption properties.

To obtain flax fiber, one of the types of flax is used - fiber flax. It has a straight, unbranched stem up to 90 cm long. 12 weeks after sowing the seeds, the formation of fiber bundles in the flax stem ends. When harvesting flax during this period, the highest yield of fiber of good quality is obtained.

The elementary fibers of flax are spindle-shaped with thick walls, a narrow channel and closed pointed ends. The length of these fibers ranges from 15 to 20 mm. Elementary fibers, collected in bundles of 15-20, are evenly distributed around the circumference of the stem under its integumentary tissue. The cross section of the fiber has the form of a five- or six-sided polygon with a channel trace in the center (Fig. 3a). Under the microscope, the elementary fiber of flax in the longitudinal form is a cylinder with knee-shaped shifts and thickenings (Fig. 3, b).

The bundles of elementary fibers released from the flax stem during its processing form an industrial fiber. Elementary fibers are held in this bundle due to the successive wedging of the pointed ends of some fibers into the gaps between others. Technical fibers isolated from the stems for use in spinning have a length of 250-400 mm.

The strength of flax fibers is several times higher than the strength of cotton, and their extensibility, on the contrary, is less. Therefore, linen fabrics retain their shape better than cotton ones.

The proportion of plastic deformation in the total elongation of flax fiber is greater than that of cotton, and is 60-65%. This explains the even greater wrinkling of linen fabrics compared to cotton.

When heated, dry flax fibers can withstand more high temperature than cotton.

The resistance of flax to light weather is also slightly higher than that of cotton.

Linen burns with the same symptoms as cotton.

7th grade

Topic: "Properties of chemical fibers and fabrics from them."

Targets and goals:
educational

To give an idea about the types of chemical fibers, to acquaint with the methods of their production, properties and processing technology and application in the surrounding life.

Educational

Learn to understand the properties of tissues and apply this knowledge in life.

Develop the ability to analyze and compare, observation and attention.

Educational

Education of activity, accuracy, ability to work in a group.

Equipment :

Fabric collection, handout, cards, safety instructions, Textile Fiber Classification chart, computers, multimedia installation, computer presentation

Lesson type: lesson of studying and primary consolidation of new knowledge

Methods: problem-search, information-developing, reproductive, creative-reproductive.

Work in teams (3 teams - according to the number of rows in the office).

During the classes.

I. Organizational moment.

Check readiness for the lesson.

Preparing students for learning.

2 . Knowledge update according to the previous learning material. (Work in teams).For each correct answer, the team gets a bonus / at the end of the lesson - grades /.

Questions:

Blitz Poll:

(Slide 2.3)

1. Complete the sentences:

1. Cotton and linen are fibers (of plant origin)

2. Animal fibers include (wool and silk)

2. Make a daisy chain fabric making:

Plant - fiber - yarn - fabric

3. Fill in the missing words.

The thinnest fiber (silk)
Smoothest fiber (linen)
The shortest fiber (cotton)
The fluffiest fiber (wool)

4. Significant hygroscopicity (all fabrics from natural fibers)

5. Have a large dust capacity (woolen fabrics)

6. They drape better than others (silk fabrics)

3. Learning new material.

Motivation of educational activity of students
Introductory speech of the teacher:

- Have you ever wondered whypeople began to look for raw materials from which it would be possible to obtain fabric in a cheap way, warm like wool, light and beautiful like silk, practical like cotton?

Today I will tell you and at the end of the lesson you will answer the problematic question:

1. Verbal and illustrative story (Slide 4).

Teacher. Since ancient times, for the production of fabrics, people used those fibers that nature gave them. At first, these were fibers of wild plants, then fibers of hemp, flax, and also animal hair. With the development of agriculture, people began to grow cotton, which gives a very durable fiber.

But natural raw materials have their drawbacks, natural fibers are too short and require complex technological processing. And, people began to look for raw materials from which it would be possible to obtain fabric in a cheap way, warm like wool, light and beautiful like silk, practical like cotton.

Today, all textile fibers can be represented in the form of the following diagram (Slide 5).

Now more and more new types of chemical fibers are being synthesized in laboratories, and not a single specialist can enumerate their vast multitude. Scientists managed to replace even wool fiber - it is callednitron .

The production of chemical fibers includes 5 stages: (Slide 6.7)

1. Receiving and pre-treatment of raw materials.
2. Preparation of spinning solution or melt.
3. Thread forming.
4. Finishing.
5. Textile processing. Cotton and bast fibers contain cellulose. Several methods were developed to obtain a solution of cellulose, forcing it through a narrow hole (die) and removing the solvent, after which threads similar to silk were obtained. Used as solvents acetic acid, alkaline solution of copper hydroxide, sodium hydroxide and carbon disulfide. The resulting threads are called, respectively: acetate, copper-ammonia, viscose.

When molded from solutionwet In this way, the jets enter the solution of the precipitation bath, where the polymer is released in the idea of ​​the thinnest threads.

The large group of filaments emerging from the spinnerets is drawn, twisted together, and wound as a complex filament onto a cartridge. The number of holes in the spinneret in the production of complex textile yarns can be from 12 to 100.

In the production of staple fibers, the spinneret can have up to 15,000 holes. A flagellum of fibers is obtained from each spinneret. The tows are connected into a tape, which, after pressing and drying, is cut into bundles of fibers of any given length. Staple fibers are processed into yarn in their pure form or mixed with natural fibers.

Synthetic fibers are made from polymeric materials. Fiber-forming polymers are synthesized from oil refining products: benzene, phenol. ammonia, etc.

Presentation of groups with pre-prepared information:

1 group:

By changing the composition of the feedstock and the methods of its processing, synthetic fibers can be given unique properties that natural fibers do not have. Synthetic fibers are obtained mainly from the melt, for example, fibers from polyester, polyamide, pressed through spinnerets.

Depending on the type of chemical raw material and the conditions of its formation, it is possible to produce fibers with a variety of predetermined properties. For example, the stronger you pull the jet at the moment it exits the spinneret, the stronger the fiber is. Sometimes chemical fibers even outperform steel wire of the same thickness.

2 group:

Among the new fibers that have already appeared, one can note fibers - chameleons, the properties of which change in accordance with changes in environment. Hollow fibers have been developed into which a liquid containing colored magnets is poured. Using a magnetic pointer, you can change the pattern of a fabric made from such fibers.

Since 1972, the production of aramid fibers has been launched, which are divided into two groups. Aramid fibers of one group (nomex, conex, phenylone) are used where resistance to flame and thermal effects is required. The second group (Kevlar, Terlon) has high mechanical strength combined with low weight.

3rd group:

High mechanical strength and good resistance to chemicals are ceramic fibers, the main form of which consists of a mixture of silicon oxide and aluminum oxide. Ceramic fibers can be used at temperatures around 1250oC. They are distinguished by high chemical resistance, and resistance to radiation allows them to be used in astronautics.

Familiarization with various properties textile fibers

(Slide 8*)

Table "Classification of fabrics by fibrous composition" (It can be printed out by the number of students and handed out to strengthen it in a notebook, in order to save time).

4.Laboratory - practical work.

“Determination of the raw material composition of materials and the study of their properties” (Work in teams). (Slide 9)

In class during laboratory work you will see in practice what properties fabrics made of chemical fibers have and how to properly care for products made from such fabrics.

Tools and materials: samples of fabrics made of artificial and synthetic fibers, wool, cotton; needle; a vessel with water; crucibles for ignition of threads.

(Slide 10).

"Table of properties of chemical fibers"

Progress (Slide 11).

Consider the appearance of the fabric samples. Determine which of them have a shiny surface, and which have a matte surface.

Determine by touch the degree of smoothness and softness of each sample.

Determine the wrinkle of the samples: hold the sample in your fist for 30 seconds, and then open your palm.

Remove 2 threads from each sample and wet one of them. Break the dry thread and then the wet thread. Determine how the strength of the thread changes in this case.

Remove one more thread from each sample and light it in the crucible. Analyze the type of flame, smell and remaining ash after burning.

Record the results of the experiments in the table.

Based on the obtained data and the table of properties of chemical fibers, determine the raw composition of each sample.

5. Consolidation of the studied material.

1. Control of students' knowledge. (Slide 12).

In order to consolidate new knowledge, the girls respond totest

1. High shedding of threads in fabrics:

A) cotton
B) woolen
B) synthetic

2. Heat-shielding properties are higher at:

A) flax
B) silk
B) nitron

3. What fabrics are highly hygroscopic and breathable?

A) natural
B) artificial

4. What fabrics lose strength when wet?

A) natural
B) synthetic

Evaluation, their reasoning.

2.Competition between teams.

The teams were given envelopes with tissue samples, it is necessary

sort them into two groups:

1.made from natural fibers;

2. made of chemical fibers.

V. Summing up.

Conclusion: the ability to determine the nature of the raw material of the fabric is necessary for subsequent work with the fabric at all stages of the manufacture of the product.

So, our lesson has come to an end, let's remember what we learned in the lesson? Who will answer the problem?What fabrics are in high demand and why? The responses of the teams are discussed and analyzed.

The teacher sums up the lesson, the bonuses earned in the lesson are calculated, marks are given.

The teacher congratulates the team with the most points.6 .Homework.

Make a collection of fabrics.

For the creative group: make a crossword puzzle.

7 .Cleaning jobs .

Fiber materials

General information about fibers

Fiber classification

Chemical composition fibers

Main properties of fibers

Natural fibers (cotton, linen, wool, silk)

Chemical fibers (artificial and synthetic fibers)

1. General information about fibers

fibers flexible, thin and strong bodies are called, the length of which is many times greater than their transverse dimensions.

Textile called fibers that are used to make yarn, thread, fabrics, knitwear, non-woven materials, etc. Single fibers that do not divide in the longitudinal direction without destruction are called elementary (cotton, wool). Fibers consisting of longitudinally fastened elementary fibers are called technical (flax, hemp, jute, etc.).

Fibers, the length of which is tens and hundreds of meters, are called threads (threads of natural silk, artificial and synthetic threads). Threads are divided into elementary and complex. A filament is a single filament that does not divide in the longitudinal direction without destruction and is used in combination with similar filaments. An elementary thread suitable for the manufacture of products directly from it is called monofilament. Complex threads consist of longitudinally arranged elementary threads twisted or glued together. Short artificial and synthetic fibers are called staple.

2. Classification of fibers

The classification of fibers is based on their origin and chemical composition.

All fibers are divided into two classes: natural (natural) and chemical. Natural fibers are called fibers that are found in nature, chemical - fibers obtained in the factory.

Natural fibers include fibers of plant origin (cellulose - cotton, linen, hemp, jute, etc.). Animal origin (protein - wool, natural silk) and mineral origin (asbestos).

Chemical fibers are divided into artificial and synthetic. Artificial fibers are obtained from raw materials of plant, animal and mineral origin. They are divided into cellulose (viscose, acetate, triacetate, etc.), protein (casein, etc.), mineral (glass and metal).

Synthetic fibers are called fibers, upon receipt of which the synthesis (combination) of relatively simple molecules is performed. Synthetic fibers include kapron fibers, lavsan, nitron, chlorin, vinol, polyethylene, polypropylene and other fibers.

3. Chemical composition of fibers

All fibers, except for mineral fibers, are organic substances in chemical composition. These are various natural or chemically obtained macromolecular compounds (HMCs).

Mineral fibers contain in their basis inorganic substances.

All plant fibers are based on a complex organic compound - cellulose, that is, fiber containing elements such as carbon, oxygen and hydrogen.

All animal fibers are based on even more complex organic compounds - proteins, which consist of amino acids. The composition of the protein, in addition to carbon, oxygen and hydrogen, includes nitrogen. Keratin, a protein compound that forms wool, also contains sulfur. Natural silk, i.e. cocoon thread, has two proteins in its composition: fibroin and sericin.

Synthetic fibers are based on complex organic compounds - polymers consisting of long, flexible, slightly branched macromolecules.