Production of chemical fibers brief message. Abstract: Chemical fiber production technology

21.11.202327.05.2017

You are already familiar with materials made from natural fibers - cotton, linen, wool, silk. But in the modern world, more and more fabrics are made from artificial fiber. Already in the 17th century. Englishman Robert Hooke suggested the possibility of producing artificial fiber. However, artificial fiber for making fabrics was produced industrially only at the end of the 19th century. In Russia, the first plant for the production of artificial silk was built in 1913 in the town of Mytishchi near Moscow.

In the wardrobe of a modern person it is rare to find something made from natural fiber. Today, almost all natural fabrics contain additives that improve their properties.

When purchasing fabrics, textiles and knitwear, you cannot focus only on their appearance. In order to properly care for an item, it is very important to know the raw material composition and properties of this material.

Chemical fiber production technology

Chemical textile fibers are produced by processing raw materials of different origins. On this basis they are divided into artificial and synthetic. The raw material for the production of artificial fibers is cellulose obtained from spruce wood and cotton waste. The raw materials for the production of synthetic fibers are gases - products of the processing of coal and oil.

The production of chemical fibers is divided into three stages:

Obtaining a spinning solution. All chemical fibers, except mineral ones, are produced from viscous solutions or melts, which are called spinning. For example, artificial fibers are obtained from cellulose mass dissolved in alkali, and synthetic fibers are obtained by combining chemical reactions of various substances.
Fiber forming. The viscous spinning solution is passed through dies - caps with tiny holes. The number of holes in the die ranges from 24 to 36 thousand. Streams of solution flowing out of the dies harden, forming solid thin threads. Next, the threads from one spinneret are combined into one common thread on spinning machines, pulled out and wound onto a bobbin.
Fiber finishing. The resulting threads undergo washing, drying, twisting, and heat treatment (to fix the twist). Some fibers are bleached, dyed and treated with a soap solution to make them soft.

New concepts

Chemical fibers: artificial, synthetic; cellulose.

Control questions

1. What is the production technology of chemical textile fibers? 2. What are the raw materials for the production of chemical fibers?

Development of a technology lesson.

Designed by technology teacher

"Comprehensive school No. 2 of the Akimat of Shakhtinsk"

Karaganda region of the Republic of Kazakhstan

Sultangareeva Luiza Makhmutovna

Class 7

Chapter: Getting to know fabrics.

Duration: 1 hour

Topic: Chemical fibers, their properties. Technology for the production of chemical fibers.

Ecological influence of tissues on the human body.

create conditions for generalizing, systematizing and expanding students’ knowledge about textile fibers, their properties, and fabric production processes;

contribute to the formation of knowledge about the technology of production of fabrics from chemical fibers and their range;

help identify gaps in students’ knowledge and correct them;

promote the development of the ability to analyze information, observation and attentiveness, thinking;

contribute to the development of positive motivation for the subject, activity in work in the classroom, accuracy, as well as a culture of behavior.

- Clarification and consolidation of knowledge about natural fibers.
- Introduction to the technology of producing chemical fibers.
- Nonwoven materials made from chemical fibers.
- Assortment of fabrics.

Visibility and equipment:

Collections of fabric samples from chemical and natural fibers;

Power Point presentation “Production of fabrics from chemical fibers”;

Information materials “Properties of fabrics made from chemical fibers”

DURING THE CLASSES.

Organizing time.

a) greeting;

b) identification of absent students;

c) organizing students’ attention.

Pay attention to the board on which fabric samples are placed (including non-woven ones - batting, padding polyester).

Introductory part of the lesson.

1. Report the topic of the lesson. Introduction to the topic of the lesson.

Look at your clothes. What is it made of?

Do you know what materials these fabrics are made of?

Are these materials natural or man-made?

Take a look at the window curtains. What can you say about this fabric? What are its undoubted advantages? What about the disadvantages?

Is it possible to make clothes from this fabric? Why?

Today in the lesson we will talk about chemical fibers, their production technology and the properties of fabrics made from these fibers.

2. Formulation of educational goals of the lesson together with students:

What are we going to study today?

study the features of the production of chemical fibers;

find out where it is advisable to use fabrics made from chemical fibers (in accordance with their properties).

3. Updating students' knowledge. Conversation.

What are the stages of fabric production?

Name the groups of fibers based on their origin.

4. Summarizing answers. Summing up the conversation.

III. Main part of the lesson

1. Teacher's story “Production of chemical fibers” using Presentation materials.

Receiving technology chemical fibers of both groups are the same: raw materials (organic substances) + chemical solvents, a liquid viscous mass is obtained. This mass is pressed through filters (dies), thereby forming threads. These threads are then immersed in a bath of hardeners and, after processing and washing, wound onto bobbins to form continuous threads.

Advances in modern chemistry make it possible to create chemical fibers from natural materials, mainly cellulose obtained from wood, straw, and cotton waste. This fiber is called artificial, and from synthetic polymers, products of processing of coal and oil. This fiber is syntheticslogical(write in a notebook in the form of a diagram).

It is very difficult to list the many chemical fibers that are used to produce fabrics. And more and more types of them are synthesized in laboratories.

Independent work of students

Problem. Research "Reasons and features of the creation of chemical fibers."

Working with the information material “Properties of fabrics made from chemical fibers”» by subgroups.

Presentation of the studied material. Carousel method. One of the team members goes to the other team and tells the content of their material.
Discussion.

- Reasons for creating chemical fibers (Cost. Dependence on natural and weather conditions. etc.).
- Stages of creation.
- Properties of chemical fibers. (Special, original properties:

The strongest fiber;

Fiber with high hygienic properties;

Fabrics with high thread spread, etc.

Analysis of student responses. Addition and clarification.
Working with a collection of fabric samples.

- name the numbers of samples of fabrics made from chemical fiber
- determine the areas of application of this fabric in everyday life.

Students' work in notebooks " Recording the main stages of chemical fiber production»

IV. The final part of the lesson.

Consolidation of what has been learned. Oral dictation.

If you agree with the statement, clap your hands. Express your disagreement with silence.

Statements:

1. Chemical fibers are divided into two groups: artificial and synthetic.

2. The raw materials for producing artificial fibers are minerals: oil, coal, gas.

3. The raw materials for producing synthetic fibers are: spruce chips, waste from cotton processing.

4. The technology for producing chemical fiber threads is uniform and simple:

Raw materials + solvents = viscous mass.

Formation of threads through filters.

Treatment of threads with hardener, washing.

Rewinding into bobbins.

5. Chemical fibers are light, beautiful, and dry quickly.

6. Less money and time are spent on producing chemical fibers - they are more economical.

7. Synthetic fibers have very high hygienic properties: hygroscopicity.

8. When producing fabrics, it is undesirable to combine chemical fibers with natural ones, since they are incompatible.

9. Fabrics made from chemical fibers have low strength.

10. Are chemical fibers mixed with natural ones (to improve the properties of fabrics).

Reflection: conversation.

What new and interesting (unexpected) did you learn in class?

How will this knowledge be useful to you in life?

Summing up the lesson.

Analysis of student responses. Giving grades for work in class.

Issuing homework.

Complete the creative task “Using fabrics made from chemical fibers in everyday life” (making a craft - a model “Ball Gown”; curtains; panels, etc.)

Draw the attention of students to the special properties of fabrics made from chemical fabrics: fluffiness, rigidity of the fabric, waterproofness, transparency. Demonstration of samples from the Teacher’s Methodological Fund (work of previous years’ students).

Annex 1

Information material 1

“Chemical fibers, their properties. Chemical fiber production technology"

In the modern world, more and more fabrics are made from chemical fiber. It is rare to find an item made only from natural fiber in the wardrobe of a modern person. Nowadays, almost all natural fabrics contain additives that improve their physical and mechanical properties. They were man-made chemical fibers. However, it should be noted that there is a decrease in hygienic properties.

Chemical textile fibers are obtained by processing miscellaneous according to the origin of raw materials.

On this basis they are divided into two groups:

Artificial (viscose, acetate, copper-ammonia);

Synthetic (polyester, polyamide, polyacrylonitrile, elastane).

Stages of obtaining chemical fiber.

Stage I: Obtaining a spinning solution.

For artificial fiber: Dissolving cellulose mass in alkali.

For synthetic fiber: the addition of chemical reactions of various substances.

Stage II: Fiber formation.

Passing the solution through dies.

The number of holes in the die is 24-36 thousand.
The solution hardens to form hard, thin threads.

Stage III: Fiber finishing.

The threads are washed, dried, twisted, and treated with high temperature.

Bleached, dyed, treated with soap solution.

Characteristics of the properties of fabrics made from chemical fibers

Properties of fabrics	Indicators of fabric properties
Properties of fabrics	viscose	acetate	nylon	lavsan	nitrone
Physical and mechanical:
Strength	decreases when wet	Less than viscose, decreases when wet	Very high
Wrinkleability		Small	Small
Drapability
Hygienic:
Hygroscopicity
Breathability			Minor
Water permeability
Heat protection	Short	Less than viscose			Very high
Technological:
		Small
Sliding the threads			Significant
Shatterability			Significant		Minor
Wear resistance

Appendix 2

Information material 2

Benefits of chemical fibers

Benefit name	Description
Wide raw material base.
High profitability of production	Cotton fiber, for example, grows by only 3-4 cm in three months, while chemical fibers are produced at a speed of hundreds of meters per minute. The following figures indicate the greater efficiency of the production of such fibers: it takes 200 working days to obtain a ton of cotton, 400 working days to obtain a ton of flax, and only 50 working days to obtain a ton of viscose fiber.
Independence from climatic conditions.	To get a lot of wool, you need huge pastures for sheep. To grow cotton, flax, etc., fertile soils are required. To obtain natural silk, mulberry tree plantations are needed. In all these cases, the harvest of products is highly dependent on drought and rain, late or early spring, and the timing of autumn and frost. The production of synthetic fibers can be organized in almost any area, and is not affected by weather conditions.
Many chemical fibers also have the best mechanical properties.	Fabrics made from these fibers have high strength, elasticity, wear resistance and less wrinkleability. This is why blended fabrics appeared: natural fibers are combined with chemical fibers to improve the properties of the fabrics.
Availability new properties, impossible for natural fibers.	In the 60-70s. chemical fibers have been created from polymers with specific properties, for example: heat-resistant fibers (from aromatic polyamides, polyimides, etc.) that can withstand long-term operation at 200-300° C; heat-resistant carbon fibers, chemical fibers obtained by carbonization and having high heat resistance (in oxygen-free conditions up to 2000 ° C, in oxygen-containing environments up to 350-400 ° C); fluorine fibers (from fluorine-containing carbon-chain polymers), resistant in aggressive environments, physiologically harmless, with good anti-friction and electrical insulating properties. Some of these fibers are also characterized by higher strength, modulus, greater elongation, etc. than conventional chemical fibers. However: the disadvantage of some chemical fibers, for example polyacrylonitrile, polyester, is low hygroscopicity.

Man-made fibers are fibers created artificially through physical and chemical processes.

The production of chemical fibers has a great influence on the development of the textile industry - the range of fabrics is significantly expanded, their properties are improved, new types of fabrics are created through a mixture of different fibers, etc. There is a constant increase in the production of fabrics from chemical fibers.

This is because:

Many chemical fibers are not inferior to natural ones in their physical, mechanical and hygienic properties, and often surpass them;
fibers can be obtained with desired properties;
The costs of producing chemical fibers are significantly lower than those of natural fibers.

Depending on the type of raw material, chemical fibers can be artificial or synthetic.

Man-made fibers

Artificial fibers are produced from wood and cotton cellulose. The fiber production process consists of preparing cellulose (drying, treating with a solution of sodium hydroxide, in which it swells, while soluble impurities are removed), obtaining a spinning solution (dissolving the mass in alkali and obtaining a viscous solution), spinning and finishing the fiber.

Fiber forming

The viscous solution is fed through pipeline 1 to the spinning machine.

1 - pipeline;
2 - piston pump;
3 - filter;
4 - die;
5—precipitation bath;
6,7 - spinning discs;
8 - funnel;
9 - centrifuge.

Under the pressure created by the piston pump 2, the solution passes through the filter 3 and is forced through the die 4 into the precipitation bath 5 containing an aqueous solution of sulfuric acid. The die is a cap made of anti-corrosion metal with 24 - 36 holes with a diameter of 0.07 - 0.08 mm. When a viscous solution interacts with sulfuric acid, cellulose is reduced, its streams harden, forming solid thin threads.

On centrifugal spinning machines, the elementary threads are combined into one complex thread, which passes through a system of spinning disks 6 and 7, is pulled out, and enters through a funnel 8 into a rotating centrifuge 9. The thread is wound onto a bobbin.

Finishing

Finishing consists of a number of operations: washing (to remove sulfuric acid), bleaching, treatment with a soap solution to make the fibers soft and friable, etc.

Artificial fibers are obtained in the form of filament threads and. A feature of the production of staple fiber is the use of larger dies, with a number of holes from 1600 to 12,000. The threads from each spinneret are combined into a common bundle, which, after finishing operations, is fed to a cutting machine, where it is cut into short pieces.

“Service labor”, S.I. Stolyarova, L.V. Domnenkova

Fabrics made from artificial and synthetic fibers are widely used both in everyday life and in industry. Viscose threads are used to make lining fabrics (twill, satin lining), dress fabrics (crepe marocquin, taffeta), shirt fabrics (tartan, pique), linen fabrics (canvas), as well as decorative and raincoat fabrics. Mixed with cotton, chemical fibers are used to produce knitwear and sportswear. Acetate fibers go...

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1. Main stages of chemical fiber production

2. High-strength, heat-resistant and non-flammable fibers and threads (phenylone, vnivlon, oxalon, armid, carbon and graphic): composition, structure, preparation, properties and application

3. Determine the type of fiber and draw a drawing of its cross and longitudinal sections; if it burns slowly, it emits the smell of burnt horn or feather. This forms a black ball that is easily ground into powder. The fiber dissolves when boiled in a 65% nitric acid solution, as well as in concentrated nitric acid and 5 and 40% sodium hydroxide solutions and does not dissolve in organic solvents

Bibliography

1. Main stagesproduction of chemical fibers

Chemical fibers include those created in a factory by forming them from organic natural or synthetic polymers or inorganic substances. Artificial fibers are obtained from high-molecular compounds found in finished form (cellulose, proteins). Synthetic fibers are made from high molecular weight compounds synthesized from low molecular weight compounds. They are divided into heterochain and carbon chain fibers. Heterochain fibers are formed from polymers whose main molecular chain contains atoms of other elements in addition to carbon atoms. Carbon chain fibers are fibers that are obtained from polymers that have only carbon atoms in the main chain of molecules.

The prototype for the process of obtaining chemical threads was the process of formation of threads by silkworms when curling a cocoon. Existed in the 80s. XIX century The not entirely correct hypothesis that the silkworm squeezes out the fiber-forming liquid through the silk glands and thus spins the thread formed the basis of the technological processes for the formation of chemical threads. Modern methods of forming threads also involve pressing initial solutions or polymer melts through the thinnest holes of spinnerets.

The production of man-made fibers consists of five main stages: receipt and pre-processing of raw materials, preparation of the spinning solution or melt, formation of threads, finishing and textile processing. Artificial fibers are obtained from various natural raw materials - wood, cotton waste, metals, which, during the pre-processing process, are purified or converted into new high-molecular compounds.

To obtain synthetic fibers, the starting materials are gases, oil, coal, the processing products of which are used for the synthesis of fiber-forming polymers.

The production and pre-processing of raw materials for artificial fibers and threads consists of their purification or chemical transformation into new polymer compounds. Raw materials for synthetic fibers and threads are obtained by synthesizing polymers from simple substances at chemical industry enterprises. These raw materials are not pre-processed.

Preparation of a spinning solution or melt. In the manufacture of chemical fibers and threads, it is necessary to obtain long thin textile threads with longitudinal orientation of macromolecules from a solid initial polymer, i.e. it is necessary to reorient the polymer macromolecules. To do this, the polymer must be transferred to a liquid (solution) or softened (melt) state, in which intermolecular interaction is disrupted, the distance between macromolecules increases and it becomes possible for them to move freely relative to each other. Solutions are used in the production of artificial and some types of synthetic threads (polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride). From the melts, heterochain (polyamide, polyester) and some carbon chain (polyolefin) fibers and threads are formed.

The spinning solution or melt is prepared in several stages.

The polymer is dissolved or melted in order to obtain a solution or melt of the desired viscosity and concentration.

Mixing polymers from different batches is carried out to increase the homogeneity of solutions or melts in order to obtain fibers with uniform properties throughout their entire length.

Filtration is necessary to remove mechanical impurities and undissolved polymer particles from a solution or melt in order to prevent clogging of dies and improve the properties of the fiber; by repeatedly passing a solution or melt through filters.

Deaeration consists of removing air bubbles from the solution, which, falling into the holes of the dies, are cut off by a stream of solution and prevent the formation of fibers; carried out by keeping the solution under vacuum for several hours. The melt is not deaerated, since there is practically no air in the molten mass of polymer.

Formation of threads. It consists of dosed pressing of the spinning solution or melt through the holes of the spinnerets, solidification of the flowing streams and winding of the resulting threads onto receiving devices. Streams are formed into elementary filaments from solution. When forming streams of filaments from the melt, flowing from the spinneret, they are cooled in the blowing shaft by a stream of air or inert gas. When formed from a solution using the dry method, streams of polymer are treated with a stream of hot air, as a result of which the solvent evaporates and the polymer hardens. In the case of formation from a solution using the wet method, a stream of threads from the spinnerets enters the solution of the precipitation bath, where the physicochemical processes of releasing the polymer from the solution and sometimes chemical changes in the composition of the original polymer occur. In the latter case, one or two baths are used to form the thread.

When formed, either complex threads are obtained, consisting of several long elementary threads, or staple fibers - sections of threads of a certain length. To obtain complex textile threads, the number of holes in the filter can be from 12 to 100. The formed threads from one spinneret are connected, drawn and wound.

Chemical fibers and threads immediately after formation cannot be used for the production of textile materials. They require additional finishing, which includes a number of operations.

Removing impurities and contaminants is necessary when producing viscose, protein and some types of synthetic threads formed by the wet method. This operation is carried out by washing the threads in water or various solutions. Whitening of threads or fibers, which are subsequently dyed in light and bright colors, is carried out by treating them with optical brighteners.

Drawing and heat treatment of synthetic threads are necessary to rebuild their primary structure. As a result, the threads become stronger, but less stretchable. Therefore, after drawing, heat treatment is carried out to relax internal stresses and partially shrink the threads. Surface treatment (air coating, finishing, oiling) is necessary to make the threads suitable for subsequent textile processing. With this treatment, slip and softness increases, surface gluing of elementary threads and their breakage decreases, electrification decreases, etc.

Drying of threads after wet formation and processing with various liquids is carried out in special dryers.

Textile recycling. This process is intended to connect threads and increase their strength (twisting and fixing the twist), increasing the volume of thread rolls (rewinding), and assessing the quality of the resulting threads (sorting).

One of the main directions for expanding and improving the range of chemical fibers is the modification of existing ones to give them new predetermined properties

2. High-strength, heat-resistant and non-flammable fibers and threads (phenylone, vnivlon, oxalon, armid, carbon and graphic): composition, structure, p Preparation, properties and application

Fibers with special properties include fibers with specific properties: heat- and heat-resistant, fibers that can withstand elevated, high and very high temperatures (from 250 to 3000 0 C), semi-permeable hollow fibers for membrane separation of liquid and gas mixtures, etc. The creation of fibers with special properties has made it possible to dramatically expand the boundaries of the use of chemical fibers.

Heat resistant fibers designed for operation at temperatures of 250-400 0 C, i.e. above the decomposition area of conventional chemical fibers for mass use. The production of such fibers requires the solution of complex scientific and technical problems associated with the synthesis of polymers and their processing into fiber. Polymers for heat-resistant fibers must satisfy a number of requirements, the most important of which are: high melting and glass transition temperatures and thermal stability. These requirements are met by aromatic, heterocyclic and ladder polymers, for the synthesis of which bi- and tetrafunctional aromatic compounds are used. The formation of heterocycles in the polar chain leads to an increase in the thermal resistance of fibers.

A large number of different types of heat-resistant fibers are known. Of these, the most widespread are fibers based on aromatic polyamides nomex (phenylone), polyimide, polyoxadiazole, polybenzimidazole and ladder fibers.

Heat-resistant and non-flammable fibers: vnivlon - super high-modulus SVM fiber; Oxalone, aramid T, Kevlar, Nomex, phenylone - contain a benzene ring in their structure. For example, Nomex fiber (form. 2.1):

Phenylone is a trade name adopted in the USSR for a linear aromatic polyamide - poly- m-phenylene isophthalamide, (in the USA it is known as “Nomex”). (form.2.2)

[- HMC 6 H 4 NHOCC 6 H 4 CO -] n(2.2)

Phenylone is produced by the polycondensation of isophthalic acid dichloroanhydride and m-phenylenediamine in an emulsion or solution. Phenylone is a white polymer, t glass 270 °C; when heated to 340-360 °C it crystallizes, t pl 430°C; molar mass 20,000-120,000. Dissolves in concentrated sulfuric acid, dimethylacetamide and dimethylformamide containing additives, such as LiCl or CaCl 2; does not burn, is chemically resistant to boiling water, to the action of fuels, oils, some mineral and organic acids, alkalis, resistant to radiation, and mold damage.

Products made from phenylone are characterized by high strength (in compression and bending 240 MN/m2 , or 2409 kgf/cm 2) and dielectric properties (dielectric loss tangent 0.01) in the temperature range from -70 to 250 °C. Phenylone is used to produce fiber, electrical insulating paper, varnish and films, and also as a structural and anti-friction material in the electrical, radio engineering and mechanical engineering industries. Phenylone fibers and films. are obtained by molding from solutions, products - by pressing and press casting at 320-340°C.

Normex fiber is used to make protective clothing against exposure to heat and light for work in hot shops, as well as for firefighters and racing drivers. All heat-resistant fibers are non-flammable or low-flammable, so they can be used as decorative and upholstery textile materials in aircraft, ships, hospitals, hospitals, schools and other public buildings.

Vnivlon is a heat-resistant, high-strength polymer synthetic fiber. It was developed in the USSR, but has analogues in other countries. The fiber is characterized by increased resistance to abrasion, deformation, high temperatures, and chemical attack. Vnivlon fibers are used for the production of technical threads and fabrics, from which thermal protective and chemical protective suits, various workwear, and body armor are sewn. The fabric can be duplicated. PVA polyvinyl alcohol fiber (form. 2.3):

(-CH 2 -CH(OH) -) n (2.3)

Oxalon is a highly heat-resistant, high-modulus fiber. It can be produced in a modified form and be non-flammable and highly chemical resistant. Fabrics from oxalone for covering ironing presses, as well as workwear. It is assumed that oxalone will also find application as high-temperature electrical and thermal insulation.

Fiber Oxalone is resistant to dilute acids and alkalis, and in the structure of dense fabric does not ignite in a flame.

Note that the sulfone and oxalone has relatively high temperature strength; fiberglass has high temperature and chemical resistance, but low bending and abrasion strength; Polyphene is characterized by exceptionally high chemical strength, but it is easy to flow.

In recent years, the production of synthetic fabrics has been organized that are more heat-resistant than nitron and lavsan, namely Teflon, Filteron, sulfone, oxalone. The heat resistance of these materials is respectively 230; 270; 260 and 250 C. Teflon fabrics are used to clean chlorine gas from dust.

All heat-resistant fibers are formed from melts, since the melting point of heat-resistant polymers lies in the region of their thermal decomposition and it is impossible to obtain melts.

Due to the poor solubility of aromatic polymers, only organic aprotic solvents (dimethylformamide, dimethylacetamide, etc.) and concentrated acids (sulfuric, oleum, polyphosphoric) are used as solvents.

TO non-flammable fibers refer to fibers that do not ignite and do not spread flame. Synthetic fibers such as polyamide, polyester, polyolefin melt at elevated temperatures. Before melting, synthetic fabrics shrink greatly. Therefore, if clothing made of synthetic materials catches fire, severe shrinkage can cause closer contact of the released material, which can lead to severe burns. Non-flammable chemical fibers include polyvinyl chloride, chlorine, fluorolone, polytetrafluoroethylene fiber and heat-resistant fibers based on aromatic polyamides and polyesters, heterocyclic and ladder polymers.

There are no universal methods for fire protection of textile materials, since the combustion process of fibers occurs through various mechanisms and depends mainly on the chemical nature of the polymer and the nature of the products released during thermal-oxidative decomposition.

To give chemical fibers increased resistance to fire, various methods are used: surface treatment of fabrics; adding additives to the polymer before molding; chemical modification of fibers or products made from them.

The simplest technologically is the surface finishing of fabrics, which includes the following stages: impregnation of the fabric with an aqueous solution of appropriate substances, drying and heat treatment. Nitrogen-, phosphorus-, sulfur- and halogen-containing products are used to treat fabrics. The amount of sizing applied is 15-100% and depends on the nature of the original fiber and the purpose of the fabric. In order to prevent these products from being washed out during subsequent washes, the fabrics are subjected to heat treatment under certain conditions, resulting in chemical transformations of the substances used. This leads to the formation of an insoluble product on the surface of the fabric, which includes phosphorus, nitrogen or halogens, and partially to its chemical attachment to the fiber. However, in most cases, fire-retardant fibers or fabrics applied to the surface, coatings that are not resistant to water treatments, are gradually washed out of the fabric. When applying a large amount of the drug, tissue stiffness increases greatly. chemical fiber thread carbon

A rather promising method is the modification of fibers or parts of them by chemically adding an antiprien to the polymer. Chemical modification makes it possible to obtain fiber with high and stable fire-retardant properties. To reduce the flammability of textile materials by chemical modification, reactions of polymer-analogous transformations and graft polymerization are used. This method has proven to be particularly effective in producing non-flammable polyamide fibers. A very significant method is the fact that non-flammable polyamide fibers obtained by this method lose their fusibility.

Despite the large number of means proposed for the fire protection of chemical fibers and numerous studies in this direction, it can be considered that only the problem of obtaining fire-resistant cellulose materials has been satisfactorily solved. The ability of most traditional synthetic fibers to melt makes it difficult to develop sufficiently effective and technologically simple methods for imparting fire resistance to them.

Inorganic chemical fibers- obtained by high-temperature processing of natural substances: sand, chalk, alumina, dolomite, kaolin. These include fiberglass, silica, aluminosilicate, and quartz. These fibers are mainly used for technical purposes.

Carbon fiber is a material consisting of thin threads with a diameter of 5 to 15 microns, formed primarily by carbon atoms. The carbon atoms are arranged into microscopic crystals aligned parallel to each other. The alignment of the crystals gives the fiber greater tensile strength. Carbon fibers are characterized by high tensile strength, low specific gravity, low coefficient of thermal expansion and chemical inertness.

Carbon fiber is usually produced by heat treating chemical or natural organic fibers, which leaves primarily carbon atoms in the fiber material. Temperature treatment consists of several stages. The first of them is the oxidation of the original (polyacrylonitrile, viscose) fiber in air at a temperature of 250 °C for 24 hours. As a result of oxidation, ladder structures are formed. After oxidation, the carbonization stage follows - heating the fiber in nitrogen or argon at temperatures from 800 to 1500 °C. As a result of carbonization, graphite-like structures are formed. The heat treatment process ends with graphitization at a temperature of 1600-3000 °C, which also takes place in an inert environment. As a result of graphitization, the amount of carbon in the fiber is increased to 99%. In addition to ordinary organic fibers (most often viscose and polyacrylonitrile), special fibers from phenolic resins, lignin, coal and petroleum tars can be used to produce carbon fiber.

Carbon fiber has exceptionally high heat resistance: when exposed to heat up to 1600-2000 °C in the absence of oxygen, the mechanical properties of the fiber do not change. Their maximum operating temperature in air is 300--350°C. Applying a thin layer of carbides, in particular SiC, or boron nitride, to carbon fiber can significantly eliminate this drawback. Due to its high chemical resistance, carbon fiber is used for filtering aggressive media, purifying gases, making protective suits, etc. By changing the heat treatment conditions, it is possible to obtain carbon fiber with different electrical properties (volumetric electrical resistivity from 2·10?3 to 106 ohm/cm) and use them as electric heating elements for various purposes, for the manufacture of thermocouples, etc.

Graphite and non-graphitized types of carbon differ in their properties. Graphite is superior to carbon in electrical properties and thermal conductivity. Technical graphite is a polycrystalline heat-resistant material obtained by mixing a filler (burnt petroleum coke) and a binder - coal tar pitch. This mixture is shaped and fired in an inert atmosphere. To accelerate crystal growth, the material is then heated to 1927-3038 C. The technical product often contains a significant amount of graphite with a defective crystal lattice, as well as with intergranular interfaces and voids. However, the insufficient surface chemical resistance of artificial graphite prevents its use at high temperatures. And the use of artificial graphite in conditions of high temperatures and erosion limits oxidation. However, recent research in the field of graphite coatings indicates that a partial solution to this problem may be possible in the near future. Soviet and other researchers found that oxidative destruction of carbon materials and graphite at 1200 °C for 100 hours can be prevented using glass silicide coatings. The creation of artificial graphite in the form of elastic fibers and fabrics by Union Carbide Corporation has already made it possible to use graphite in many new fields of technology, in particular in rocket science

3. Determine the type of fiber and make a drawing of its cross and longitudinal sections; if it burns slowly, it emits the smell of burnt horn or feather. This forms a black ball that is easily ground into powder. The fiber dissolves when boiled in a 65% solution of nitric acid, as well as in concentrated nitric acid and 5 and 40% solutions of sodium hydroxide and does not dissolve in organic solvents

According to the combustion characteristics, this fiber can be wool or silk because it emits the smell of burnt horn or feather, and a black ball is formed that is easily ground into powder.

According to the action of the reagents, this fiber is wool because the fiber dissolves when boiled in a 65% nitric acid solution, as well as in concentrated nitric acid and 5 and 40% sodium hydroxide solutions and does not dissolve in organic solvents. Wool fiber consists of three layers: scaly, cortical and core (Fig. 3.1).

Rice. 3.1. The structure of wool. 1- scaly layer; 2- cortical layer; 3- core layer. Longitudinal view and cross section of wool fiber: a) - fluff; b) - transitional hair; c) - spine; d) - dead hair.

Used Books

1. Buzov B.A. Materials science in the production of light industry products (garment production) / B.A. Buzov, N.D. Alymenkova; edited by B.A. Buzova. - M.: Publishing center "Academy", 2008. - 448 p.

2. Buzov B.A. Materials science of clothing production / B.A. Buzov, T.A. Modestova, N.D. Alymenkova; edited by B.A. Buzova. - M.: Light Industry Publishing Center, 1978. - 480 p.

3.Suvorova O.V. Materials science of clothing production. Tutorial. Rostov N/A: “Phoenix”, 2001-416 p.

4. Zazalina Z.A., Druzhinina T.V., Konkin A.A. Fundamentals of chemical fiber technology: M.: Khimiya, 1985-304 p.

5.Veselov.V.V., Kolotilova G.V.Chemization of technological processes in clothing production.-M.: Legprombytizdat, 1985.-128 p.

6. Structure, properties and technology for producing carbon fibers: Sat. scientific article/Auth.-comp., translated by S.A. Podkopaev. Chelyabinsk. Chelyab. State University, 2006, 217 p.

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Fiber	Shine	Tortuosity	Strength	Wrinkleability	Combustion
viscose					burns well, gray ash, smell of burnt paper.
acetate			decreases when wet	less than viscose	burns quickly with a yellow flame, leaving a melted ball
				very small	melts to form a solid ball
				very small	burns slowly, forms a hard dark ball
				very small	burns with flashes, a dark influx is formed

Fabric sign	Sample No. 1	Sample No. 2

Smoothness
Softness
Wrinkleability
Shatterability
Wet strength
Raw material composition

Lesson activities
Learning new material
Independent work


Evaluation criteria		“5”-18-21 “4”-14-17 “3”-10-13 “2”-less than 10

Chemical fiber production technology

New concepts

Control questions

Man-made fibers

Fiber forming

Finishing

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