Fiber table. Fiber. Formula. Properties. Application. Cotton (cotton fabric). Wool. -----------. Natural silk. -----------. Viscose. Acetate. Lavsan. Capron. (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, that is, it stretches and wrinkles strongly. Resistant to acids and alkalis. Manufacturing of various types of clothing, 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. Manufacturing of various fabrics, knitwear, carpets, felted products, high-quality beaver, blankets, blankets. Possesses the properties of high hygroscopicity, easy paintability, pleasant moderate gloss. It has good mechanical properties. Low resistance to alkalis, more resistant to mineral acids and organic solvents. Silk is not very resistant to light. Production of dresses, shirts, linings, raincoats, suits, coats, ties, items of women's dress, haberdashery, as well as scarves, tablecloths and bedspreads. High hygiene, hygroscopicity. High wet strength loss, slight crumpling, insufficient frictional resistance and low modulus of elasticity, especially when wet. Low resistance to alkalis and acids, more resistant to organic solvents. Production of silk and staple fabrics, knitwear, fabrics for various purposes from blends of viscose fiber with cotton or wool, as well as other chemical fibers. High elasticity (low crease), pleasant to the touch, soft, transmits ultraviolet rays; tensile strength is low, low thermal stability, low abrasion resistance and high electrification. The fiber is not resistant to the action of even dilute solutions of alkalis and acids; soluble in some organic solvents. Manufacturing of consumer goods (outerwear, ladies' underwear, lining and dress fabrics). Acetate staple fiber is used for the manufacture of fine cloth and some knitwear. High temperature resistance. 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 abrasion resistance 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, driving 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 to make knitwear, fabrics such as taffeta, crepes, etc. In pure or mixed form, it is used to make artificial fur, carpets. It has the properties of high temperature resistance, high tensile strength, excellent abrasion and shock resistance. It is resistant to the action of many chemical reagents, it resists well to biochemical influences, it is stained with many dyes. It dissolves in concentrated mineral acids, phenol, cresol, trichloroethane, etc. Poorly resistant to light, especially ultraviolet rays. Strongly electrified. It is used in the production of consumer goods, tire cord, industrial rubber goods, 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). By 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" - When making fibers, the die can have up to 40,000 holes. The trickle flowing out of the dies solidifies to form filaments. Raw materials for artificial fibers are obtained by isolation from naturally occurring substances. Pulling and heat treatment of the fiber. After stretching, the threads are heat-set.

"Types of fabrics" - The color of the skin can be natural and dyed. Artificial fur is made on a knitted or woven basis. Insulating materials. Ribbons: satin, jacquard, nylon, decorative. Mechanical method. Knitting and stitching method. Interlining materials are used to stiffen the details of the garment.

"Features of fabrics" - Yarn defects. Research. Plain weave. Fabric sizes. Geometric properties. The ability of a fabric to change moisture resistance. The cut through depends on the density of the fabric. Shine. Slip. Air permeability. The ability to form. Rounded folds. The ability to stretch the fabric under the iron.

1. Fiber table;

• 1. Fiber table;

• 2. Chemical fibers;

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

• 4. Natural fibers;

• 5. Fibers of plant origin;

• 6. Fibers of animal origin;

• 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 high-molecular compounds, mainly 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 from a single fiber, or in the form of staple fibers - short pieces (staples) of untwisted fiber, the length of which corresponds to the length of the wool or cotton fiber. Staple fiber, like wool or cotton, serves as an intermediate product for yarn production. Before spinning, staple fiber can be mixed with wool or cotton.

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

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

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

When the fibers are formed from the polymer melt, thin streams of melt from the holes of the die enter the space, where they are cooled and solidified. 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 evaporates and the streams solidify into fibers; wet formation, when trickles of polymer solution from the spinneret enter the so-called precipitation bath, in which the trickles of polymer are hardened into fibers under the influence of various chemicals contained in it.

In all cases, the fiber is formed under tension. This is done in order to orient (arrange) linear molecules of a high molecular weight substance along the fiber axis. If this is not done, the fiber will be much weaker. To increase the strength of the fiber, it is usually further stretched after it has partially or completely hardened.

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

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

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

• Vegetable fibers form on the seed surface

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

- jute, hemp hemp, kenaf, etc.) and in leaves (hard leafy 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. When they are formed, first the outer layer (primary wall) is formed, inside which several tens of 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 paintability 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 fabrics for household and technical purposes, knitwear

• (mainly underwear 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.

• Rough-stem fibers are processed into thick yarn for sacking and container fabrics, as well as for ropes, ropes, twines.

Animal fibers include wool and silk. Wool - fibers of the hair of sheep (almost 97% of the total wool production), goats, camels and other animals. Fibers of the following types are found in wool: 1) down - the thinnest and most elastic fiber with an inner ("cortical") layer composed of fusiform cells and an outer scaly layer; 2) awn - a thicker fiber that also has a loose core layer, which consists of sparsely located plates perpendicular to the fiber axis; 3) transitional hair, in which the core layer is discontinuous along the length of the fiber (occupies an intermediate value in thickness between down and awn); 4) "dead" hair - coarse, very thick, tough 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.

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

• Silk is a product of the secretion of the silk glands of insects, of which the silkworm has the main industrial value.

The fibers of mineral origin include asbestos (the most widely used is chrysolite-asbestos), which are split into technical fibers. They are processed (usually mixed with 15-20% cotton or chemical fibers) into yarn, from which fire-retardant and chemically resistant fabrics, filters, etc. are made. Indirect short asbestos fiber is used in the production of composites (asboplastics), cardboard, 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 industrial polyamide fibers are nylon and nylon. Enant polyamide fiber has been obtained relatively recently.

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

• The original caprolactam is practically obtained in two ways:

• 1. From phenol:

• Further, the cyclohexane oxime in an acidic medium (oleum) undergoes a Beckmann rearrangement, which is characteristic of many ketone oximes. As a result of this rearrangement, the carbon-carbon bond breaks and the cycle expands; while the nitrogen atom enters the cycle:

• 2. From benzene:

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

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

• This produces cyclohexanone and cyclohexanol in a 1: 1 ratio.

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

• During the construction of new and expansion of existing caprolactam production facilities, the second scheme of 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 duration of the reaction.

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

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

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

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

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

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

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

• Enant is obtained by polycondensation of β-aminoenanthic acid. Technological processes for producing nylon and enant fibers are similar to each other.

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

• Lavsan is a synthetic fiber made from polyethylene terephthalate.

• The starting material for the production of polyethylene terephthalate is dimethyl terephthalate (dimethyl ether 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, re-etherification occurs and diethylol terephthalate is obtained:

• Diethylol terephthalate undergoes polycondensation in vacuum (residual pressure 1-3 mm Hg) at 275-280 ° C 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 latter polycondensation reaction.

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

• At present, the largest foreign companies use as the initial monomer not dimethyl terephthalate, but highly purified terephthalic acid, which makes it possible to exclude the cumbersome step of transesterification from the technological process and, therefore, significantly reduce the cost of the entire technological process.

• The resulting polyester is poured from the reactor in the form of a tape into a precipitation 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 nylon.

• 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 significantly less wrinkled.

• Lavsan fiber is added to wool to make 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 plant, 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 silkworms.

The listed natural fibers are composed of substances that belong to natural polymers. It is cellulose in vegetable fibers and proteins in animal fibers.

Chemical fibers are subdivided into artificial and synthetic.

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

Synthetic fibers are produced by chemical synthesis of polymers, i.e. creation of substances with a complex molecular structure from simpler ones, most often from oil and coal refined products. 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 refers to the fibers that cover the seeds of the annual cotton plant. Cotton is a thermophilic plant that consumes a lot 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 matures in 130-140 days from the moment of sowing, yields fiber 25-35 mm long.

Fine staple cotton has a longer ripening period, lower yields, but gives a longer (35-45 mm), thinner and stronger fiber, which is used to make high quality yarns.

Linear density cotton fiber 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 capsules, seeds are formed, on the surface of which fibers appear - thin-walled tubes. At 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. Ripening of bolls occurs sequentially, starting from the lower branches of the bush. Therefore, cotton picking is carried out in several stages: first, the lower boxes are collected, and then the higher ones.

At the end of the ripening period, the fibers on the seeds take the form of twisted (convoluted) 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. In 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 colored. They are not suitable for textile production.

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

Under a microscope, immature fibers are flat, ribbon-like with thin walls and a wide channel inside (see Fig. 2, c). As it matures, the fiber wall thickness grows and the channel narrows. Mature fibers are flattened tubes with a characteristic spiral crimp and a channel running inside the fiber (see Fig. 2, b). Overripe fibers have a cylindrical shape, thick walls and a narrow channel (see Fig. 2, and).

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

The maturity of cotton fibers affects their strength and elongation. The proportion of plastic deformation in the total elongation of a mature cotton fiber is 50%, therefore, 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 their strength, a slight yellowness appears on them, followed by darkening, and at a temperature of 250 ° C, the fibers become carbonized. Cotton fibers burn with a yellow flame, producing gray ash and smelling burnt paper.

Cotton fiber is processed into yarn, from which fabrics, knitted and non-woven fabrics are made, sewing thread etc. Fine-staple cotton is processed into thin and smooth combed yarn, intended for the finest and highest quality fabrics - cambric, marquise. Medium-staple cotton is intended for »medium-thick fluffy yarn, from which chintz, calico, satin are made. From cotton fluff (short fibers unsuitable for spinning production), cellulose ethers are obtained, which are used for the production of artificial fibers (acetate, triacetate), as well as cellulose for the production of films, plastics, etc. In addition, fibers unsuitable for spinning are used for the production of nonwoven fabrics.

Flax fibers belong to the so-called bast fibers, that is, 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 flax is harvested during this period, the highest yield of good quality fiber is obtained.

Elementary flax fibers 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 hexagonal polygon with a channel trace in the center (Fig. 3, a). Under the microscope, an elementary flax fiber in the longitudinal view is a cylinder with knee-like shifts and thickenings (Fig. 3, b).

The bundles of elementary fibers released from the flax stem during its processing form a technical fiber. Elementary fibers are held in this bundle due to the successive wedging of the pointed ends of some fibers in the spaces between others. The technical fibers separated from the stems for use in spinning are 250-400 mm long.

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 fabrics.

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

When heated, dry flax fibers withstand more high temperaturethan cotton.

Flax's resistance to light weather is also slightly higher than that of cotton.

Flax burns with the same symptoms as cotton.

7th grade

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

Goals and objectives:
Educational

To give an idea of \u200b\u200bthe types of chemical fibers, to acquaint with the methods of their production, properties and processing technology and application in the surrounding life.

Developing

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

Develop abilities for analysis and comparison, observation and attention.

Educational

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

Equipment :

Collection of fabrics, handouts, cards, safety instructions, “Classification of textile fibers” scheme, computers, multimedia installation, computer presentation

Lesson type: a lesson in the study and primary consolidation of new knowledge

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

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

During the classes.

I. Organizational moment.

Checking readiness for the lesson.

Preparing students for lesson perception.

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

Questions:

Blitz survey:

(Slide 2,3)

1.Finish the sentences:

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

2. Fibers of animal origin include (wool and silk)

2. Make a sequential chain fabric making:

Plant - Fiber - Yarn - Fabric

3. Insert the missing words.

Finest fiber (silk)
Smoothest fiber (flax)
Shortest fiber (cotton)
Fluffiest fiber (wool)

4. They have significant hygroscopicity. (all natural fiber fabrics)

5. They have high dust holding capacity. (woolen fabrics)

6. Draped better than others (silk fabrics)

3. Learning new material.

Motivation of educational activities of students
Introduction by the teacher:

- Have you ever wondered whypeople began to look for raw materials from which it would be possible in a cheap way to get fabric as warm as wool, light and beautiful as silk, practical as 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. For a long time, for the production of fabrics, people used the fibers that nature gave them. At first, these were the fibers of wild plants, then the fibers of hemp, flax, and animal hair. With the development of agriculture, people began to grow cotton, which yields a very strong fiber.

But natural raw materials have their disadvantages, 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 as wool, light and beautiful as silk, practical as cotton.

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

Now in laboratories more and more new types of chemical fibers are being synthesized, and no specialist can enumerate their immense variety. Scientists have even succeeded in replacing woolen fiber - it is callednitron .

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

1. Receiving and preliminary processing of raw materials.
2. Preparation of a dope or melt.
3. Forming of threads.
4. Finishing.
5. Textile processing. Cotton and bast fibers contain cellulose. Several methods have been developed to obtain a cellulose solution, forcing it through a narrow hole (die) and removing the solvent, after which filaments similar to silk were obtained. Acetic acid, an alkaline solution of copper hydroxide, caustic soda, and carbon disulfide were used as solvents. The resulting threads are called, respectively: acetate, copper-ammonia, viscose.

When molded from a solutionwet In this way, the trickles fall into the solution of the precipitation bath, where the polymer is released in the idea of \u200b\u200bthe finest threads.

The large group of filaments exiting the spinnerets is pulled, twisted together, and wound as a filament around a chuck. The number of holes in the spinneret in the production of complex textile yarns can be from 12 to 100.

When producing staple fibers, the die 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 squeezing and drying, is cut into bundles of fibers of any given length. Staple fibers are processed into yarns in pure form or mixed with natural fibers.

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

Performance by groups with pre-prepared information:

1st group:

By changing the composition of the feedstock and methods of its processing, synthetic fibers can be imparted unique propertiesthat natural fibers lack. Synthetic fibers are mainly produced from a melt, for example, fibers from polyester, polyamide, pressed through dies.

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 harder the trickle is pulled at the moment it leaves the die, the stronger the fiber is. Sometimes man-made fibers are even superior to steel wires of the same thickness.

Group 2:

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

Since 1972, the production of aramid fibers has been launched, which are divided into two groups. Aramid fibers of the same group (nomex, konex, phenylone) are used where flame and thermal resistance is required. The second group (kevlar, terlon) has a high mechanical strength combined with a low weight.

Group 3:

Ceramic fibers, the main type of which consists of a mixture of silicon oxide and aluminum oxide, have high mechanical strength and good resistance to chemical reagents. Ceramic fibers can be used at about 1250oC. They are distinguished by high chemical resistance, and their resistance to radiation allows their use in astronautics.

Familiarization with different properties textile fibers

(Slide 8 *)

Table "Classification of fabrics by fibrous composition" (It can be printed by the number of students and distributed 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 the lesson during laboratory work you will see in practice what properties of fabrics made of chemical fibers and how to properly care for products from such fabrics.

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

(Slide 10).

"Table of properties of chemical fibers"

Work progress (Slide 11).

Consider the appearance of the fabric samples. Determine which ones have a shiny surface and which ones are matte.

Feel the smoothness and softness of each sample.

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

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

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

Enter the results of the experiments in the table.

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

5. Consolidation of the studied material.

1. Control of students' knowledge. (Slide12).

In order to consolidate new knowledge, girls respond totest

1. Large shedding of threads in fabrics:

A) cotton
B) woolen
B) synthetic

2. Heat-shielding properties are higher for:

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

Grading, their argumentation.

2. Competition between teams.

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

sort them into two groups:

1. made of natural fibers;

2. made of chemical fibers.

V. Summing up.

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

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

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

The teacher congratulates the brigade with the most bonuses.6 .Homework.

Create a collection of fabrics.

For the creative team: compose a crossword puzzle.

7 . Cleaning of workplaces .

Fibrous materials

General information about fibers

Fiber classification

Chemical composition fibers

Basic properties of fibers

Natural fibers (cotton, linen, wool, silk)

Man-made fibers (artificial and synthetic fibers)

1. General information about fibers

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

Textile called fibers that are used to make yarn, threads, fabrics, knitwear, nonwovens, etc. Single fibers that do not divide in the longitudinal direction without destruction are called elemental (cotton, wool). Fibers consisting of longitudinally bonded elementary fibers are called technical fibers (flax, hemp, jute, etc.).

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

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 those that are found in nature, chemical fibers are those obtained in a factory.

Natural fibers include plant fibers (cellulose - cotton, flax, 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 (connection) of relatively simple molecules is performed. Synthetic fibers include nylon 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 terms of chemical composition. These are various natural or chemically obtained high molecular weight compounds (IUDs).

Mineral fibers are based on inorganic substances.

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

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

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