Production technology properties of chemical fibers. Chemical fibers Chemical fiber production technology

These are fibers obtained from organic natural and synthetic polymers. Depending on the type of raw material, chemical fibers are divided into synthetic (from synthetic polymers) and artificial (from natural polymers). Sometimes chemical fibers also include fibers obtained from inorganic compounds (glass, metal, basalt, quartz). Chemical fibers are produced industrially in the form of:

1) monofilament (single fiber of long length);

2) staple fiber (short pieces of thin fibers);

3) filament threads (a bundle consisting of a large number of thin and very long fibers connected by twisting); filament threads, depending on their purpose, are divided into textile and technical, or cord threads (thicker threads of increased strength and twist).

Chemical fibers are fibers (threads) produced by industrial methods in a factory.

Chemical fibers, depending on the feedstock, are divided into main groups:

man-made fibers are obtained from natural organic polymers (for example, cellulose, casein, proteins) by extracting polymers from natural substances and chemically affecting them

synthetic fibers are produced from synthetic organic polymers obtained by synthesis reactions (polymerization and polycondensation) from low molecular weight compounds (monomers), the raw materials for which are petroleum and coal processing products

mineral fibers are fibers obtained from inorganic compounds.

Historical information.

The possibility of obtaining chemical fibers from various substances (glue, resins) was predicted back in the 17th and 18th centuries, but only in 1853 the Englishman Oudemars first proposed spinning endless thin threads from a solution of nitrocellulose in a mixture of alcohol and ether, and in 1891 the French engineer I. de Chardonnay was the first to organize the production of such threads on a production scale. From that time on, the rapid development of chemical fiber production began. In 1896, the production of copper-ammonia fiber from cellulose solutions in a mixture of aqueous ammonia and copper hydroxide was mastered. In 1893, the Englishmen Cross, Beaven and Beadle proposed a method for producing viscose fibers from aqueous-alkaline solutions of cellulose xanthate, carried out on an industrial scale in 1905. In 1918-20, a method was developed for the production of acetate fiber from a solution of partially saponified cellulose acetate in acetone, and in 1935 production was organized protein fibers from milk casein.

In the photo below on the right - not chemical fiber, of course, but cotton fabric.

The production of synthetic fibers began with the release of polyvinyl chloride fiber in 1932 (Germany). In 1940, the most famous synthetic fiber, polyamide (USA), was produced on an industrial scale. Industrial scale production of polyester, polyacrylonitrile and polyolefin synthetic fibers was carried out in 1954-60. Properties. Chemical fibers often have high tensile strength [up to 1200 MN/m2 (120 kgf/mm2)], significant elongation at break, good dimensional stability, crease resistance, high resistance to repeated and alternating loads, resistance to light, moisture, mold, bacteria, chemicals heat resistance.

The physicomechanical and physicochemical properties of chemical fibers can be changed in the processes of spinning, drawing, finishing and heat treatment, as well as by modifying both the feedstock (polymer) and the fiber itself. This makes it possible to create chemical fibers with a variety of textile and other properties even from one initial fiber-forming polymer (Table). Chemical fibers can be used in mixtures with natural fibers in the manufacture of new ranges of textile products, significantly improving the quality and appearance the latter. Production. To produce chemical fibers from a large number of existing polymers, only those are used that consist of flexible and long macromolecules, linear or slightly branched, have a sufficiently high molecular weight and have the ability to melt without decomposition or dissolve in available solvents.

Such polymers are commonly called fiber-forming polymers. The process consists of the following operations: 1) preparation of spinning solutions or melts; 2) fiber spinning; 3) finishing of the molded fiber. The preparation of spinning solutions (melts) begins with the transfer of the original polymer into a viscous-flow state (solution or melt). Then the solution (melt) is cleaned of mechanical impurities and air bubbles and various additives are added to it for thermal or light stabilization of the fibers, their matting, etc. The solution or melt prepared in this way is fed to the spinning machine for spinning the fibers. Fiber spinning involves forcing the spinning solution (melt) through the fine holes of a spinneret into a medium that causes the polymer to solidify into fine fibers.

Depending on the purpose and thickness of the fiber being formed, the number of holes in the die and their diameter may vary. When spinning chemical fibers from a polymer melt (for example, polyamide fibers), the medium causing the polymer to harden is cold air. If spinning is carried out from a solution of a polymer in a volatile solvent (for example, for acetate fibers), this medium is hot air in which the solvent evaporates (the so-called “dry” spinning method). When spinning fibers from a polymer solution in a non-volatile solvent (for example, viscose fiber), the threads harden, falling after the spinneret into a special solution containing various reagents, the so-called precipitation bath (“wet” spinning method). The spinning speed depends on the thickness and purpose of the fibers, as well as the spinning method.

When molding from a melt, the speed reaches 600-1200 m/min, from a solution using the “dry” method - 300-600 m/min, using the “wet” method - 30-130 m/min. The spinning solution (melt), in the process of transforming streams of viscous liquid into thin fibers, is simultaneously drawn out (spun-bonded drawing). In some cases, the fiber is additionally drawn directly after leaving the spinning machine (plasticization drawing), which leads to an increase in the strength of the fiber. and improving their textile properties. Chemical finishing of fibers involves treating freshly formed fibers with various reagents. The nature of finishing operations depends on the spinning conditions and the type of fiber.

In this case, low-molecular compounds are removed from the fibers (for example, from polyamide fibers), solvents (for example, from polyacrylonitrile fibers), acids, salts and other substances carried away by the fibers from the precipitation bath (for example, viscose fibers) are washed off. To impart properties to the fibers such as softness, increased slip, surface adhesion of single fibers, etc., after washing and cleaning, they are subjected to special treatment or oiling. The fibers are then dried on drying rollers, cylinders or drying chambers. After finishing and drying, some chemical fibers are subjected to additional heat treatment - heat setting (usually in a tense state at 100-180°C), as a result of which the shape of the yarn is stabilized, and the subsequent shrinkage of both the fibers themselves and products made from them during drying is reduced. and wet treatments at elevated temperatures.

Lit.:

Characteristics of chemical fibers. Directory. M., 1966; Rogovin Z.A., Fundamentals of chemistry and technology for the production of chemical fibers. 3rd ed., vol. 1-2, M.-L., 1964; Technology for the production of chemical fibers. M., 1965. V.V. Yurkevich.

as well as other sources:

Great Soviet Encyclopedia;

Kalmykova E.A., Lobatskaya O.V. Materials science of clothing production: Textbook. Allowance, Mn.: Higher. school, 2001412s.

Maltseva E.P., Materials science of clothing production, - 2nd ed., revised. and additional M.: Light and food industry, 1983,232.

Buzov B.A., Modestova T.A., Alymenkova N.D. Materials science of clothing production: Textbook. for universities, 4th ed., revised and enlarged, M., Legprombytizdat, 1986 – 424.

By chemical composition fibers are divided on organic and inorganic fibers.

Organic fibers are formed from polymers containing carbon atoms directly connected to each other, or including atoms of other elements along with carbon.

Inorganic fibers are formed from inorganic compounds (compounds from chemical elements other than carbon compounds).

To produce chemical fibers from a large number of existing polymers, only fiber-forming polymers are used. Fiber-forming polymers They consist of flexible and long macromolecules, linear or slightly branched, have a fairly high molecular weight and have the ability to melt without decomposition or dissolve in available solvents.

Materials Science

Completed by technology teacher

Kirchikova A.N.

Lesson objectives:

Educational:

give an idea of ​​the types of chemical fibers, introduce them to the methods of their production, properties and use in the surrounding life;

summarize and systematize students’ knowledge about the classification of fibers;

teach to determine the type of fiber by external signs, by touch and by the nature of combustion

Educational:

development of logical thinking

Educational:

Contribute to the formation of aesthetic taste and practicality

Contribute to the formation of cognitive interest in the subject

Promote the development of friendly relationships in the team

Do you like to dress beautifully? Where do you think the creation of clothes begins? What do you usually look for when buying fabric?

• Why do you need to know all this?
• To learn to understand fabrics, you need to know their properties, then you will learn how to properly care for your things and will always be the most fashionable, beautiful and practical.
• In 5th and 6th grade you were introduced to plant and animal tissues.
• Let's remember what kind of fabric these are.

Chemical fibers.

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 technology for the production of chemical fibers is divided into three stages:

• Obtaining a spinning solution. (All chemical fibers are produced from viscous solutions or melts).
• Fiber forming. (The viscous spinning solution is passed through spinneret caps with tiny holes. The number of holes in the spinneret ranges from 24 to 36 thousand. Streams of the solution flowing out of the spinnerets solidify, forming solid thin threads. Next, the threads from one spinneret on spinning machines are combined into one common the thread is 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).

ARTIFICIAL FIBERS

Viscose fiber is cellulose obtained from spruce wood, without any impurities. Depending on its purpose, viscose can have a shiny or matte surface. By changing the shine, thickness, and crimp of the fibers, viscose fabric can be given the appearance of linen, silk, cotton or wool.

Acetate does not tolerate strong heat and melts at a temperature of 210 degrees. Triacetate has greater heat resistance, its melting point is 300 degrees.

Acetate and triacetate fibers burn quickly and curl into small brown balls that smell like vinegar. If

set on fire

take out the thread

from the flames

stops.

SYNTHETIC FIBERS

• These are chemical fibers obtained from synthetic polymers. Synthetic fibers are formed either from a polymer melt (polyamide, polyester, polyolefin) or from a polymer solution (polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol) using a dry or wet method.

NONWOVEN MATERIALS FROM CHEMICAL FIBERS

THERMO-ADHESIVE INVASION FABRICS

Thermal padding - a corsage is designed to strengthen the waistband of trousers or skirts so that during use it cannot stretch, curl and take on an untidy appearance.

Questions for control

• A) nettle
• B) flax
• B) wool
• D) cotton
• D) silk
• A) changes its length
• B) does not change its length
• A) spinning
• B) weaving
• B) finishing
• A) strength
• B) wetness
• B) drapability
• D) breathability
• D) Dust capacity

• A) strength
• B) drapability
• B) spreading of threads in seams
• D) shrinkage
• D) crumbling
• B) chemical
• D) synthetic
• D) artificial

Questions for control

• 1.Fiber plant origin get from:
• A) nettle
• B) flax
• B) wool
• D) cotton
• D) silk
• 2. Lobe thread when stretched:
• A) changes its length
• B) does not change its length
• 3. The process of producing fabric from threads by weaving them is called:
• A) spinning
• B) weaving
• B) finishing
• 4.The hygienic properties of fabrics include:
• A) strength
• B) wetness
• B) drapability
• D) breathability
• D) Dust capacity

• 5.The natural color of wool fibers is:
• A) white B) black C) orange D) brown E) gray
• 6. Technological properties of fabrics include:
• A) strength
• B) drapability
• B) spreading of threads in seams
• D) shrinkage
• D) crumbling
• 7. Textile fibers are divided into natural and:
• A) vegetable B) mineral
• B) chemical
• D) synthetic
• D) artificial

Natural and chemical fibers………………………………………………………...….3

Areas of application of chemical fibers……………….………………………..5

Classification of chemical fibers………………………………………………………..…..7

Quality management of chemical fibers…………………….…………...…9

Technological process for producing chemical fibers……………...…..10

Production flexibility……………………………………………………………...………..14

List of references………………………………………………………...15

Natural and chemical fibers

All types of fibers, depending on their origin, are divided into two groups - natural and chemical. Natural fibers include organic (cotton, flax, hemp, wool, natural silk) and inorganic (asbestos) fibers.

The development of the chemical fiber industry is directly dependent on the availability and accessibility of main types of raw materials. Wood, oil, coal, natural gas and oil refining gases, which are the raw materials for the production of chemical fibers, are available in our country in sufficient quantities.

Chemical fibers have long ceased to be only substitutes for silk and other natural fibers (cotton, wool). At this time they form completely new class fibers, which has its own significance. Chemical fibers can be used to make beautiful, durable and widely available consumer goods, as well as high-quality technical products that are not inferior in quality to products made from natural fibers, and in many cases superior to them in a number of important indicators.

In the textile and knitting industry, chemical fibers are used both in pure form and in mixtures with other fibers. They are used to produce clothing, dress, lining, linen, decorative and upholstery fabrics; artificial furs, carpets, stockings, underwear, dresses, outerwear, knitwear and other products.

The rapid development of chemical fiber production is stimulated by a number of objective reasons:

a) the production of chemical fibers requires less capital investment to produce a unit of product than the production of any type of natural fiber;

b) the labor costs required for the production of chemical fibers are significantly lower than in the production of any type of natural fibers;

c) chemical fibers have a variety of properties, which ensures high quality products. In addition, the use of chemical fibers makes it possible to expand the range of textile products. No less important is the fact that the properties of natural fibers can be changed only within very narrow limits, while the properties of chemical fibers can be targeted over a very wide range by varying the conditions of spinning or subsequent processing.

Application areas of chemical fibers

Depending on the purpose, chemical fibers are produced in the form of monofilaments, multifilaments, staple fibers and tows.

Monofilaments are single threads of long length, not dividing in the longitudinal direction and suitable for the direct production of textile and technical products. Monofilament is most often used in the form of fishing line, as well as for making fishing nets and flour sieves. Sometimes monofilaments are also used in various measuring instruments.

Complex threads - consist of two or more elementary threads connected to each other by twisting, gluing, and are suitable for the direct manufacture of products. Complex threads, in turn, are divided into two groups: textile and technical. Textile threads include thin threads intended primarily for the manufacture of consumer goods. Technical threads include threads with high linear density, used for the manufacture of technical and cord products (car and aircraft tires, conveyor belts, drive belts).

Recently, complex threads with high tensile strength and minimal deformation under loading (high-modulus) have begun to be widely used for reinforcing plastics, and high-strength threads with special properties have been used for the manufacture of road surfaces.

Staple fiber, consisting of filaments of various cutting lengths, was until recently used only for the production of yarn on cotton, wool and flax spinning machines. Currently, fibers with a round cross-section are widely used for the manufacture of wall and floor carpets and the top layer of interfloor ceilings. Fibers 2–3 mm long (fibrids) are used for the manufacture of synthetic paper.

A tow, consisting of a large number of longitudinally folded filaments, is used to make yarn on textile machines.

For products of a certain range (outer knitwear, hosiery, etc.), textured threads are produced, which through additional processing are given increased volume, crimp or extensibility.

All currently produced chemical fibers can be divided into two groups based on production volume - large-tonnage and low-tonnage. Large-tonnage fibers and threads are intended for mass production of consumer goods and technical products. Such fibers are produced in large volumes based on a small number of initial polymers (GC, LC, PA, PET, PAN, PO).

Low-tonnage fibers or, as they are also called, fibers special purpose, due to their specific properties, are produced in small quantities. They are used in technology, medicine and a number of sectors of the national economy. These include thermo- and heat-resistant, bactericidal, fire-resistant, chemisorption and other fibers. Depending on the nature of the original fiber-forming polymer, chemical fibers are divided into artificial and synthetic.

Depending on the nature of the initial fiber-forming polymer, chemical fibers are divided into artificial and synthetic.

Classification of chemical fibers

Artificial fibers are produced on the basis of natural polymers and are divided into hydrated cellulose, acetate and protein. The most large-tonnage fibers are hydrated cellulose fibers produced by viscose or copper-ammonia methods.

Acetate fibers are produced on the basis of acetic acid esters (acetates) of cellulose with different contents of acetate groups (VAC and TAC fibers).

Fibers based on proteins of plant and animal origin are produced in very limited quantities due to their low quality and use for their production of food raw materials.

Synthetic fibers are produced from polymers synthesized industrially from simple substances (caprolactam, acrylonitrile, propylene, etc.). Depending on chemical structure macromolecules of the original fiber-forming polymer, they are divided into two groups: carbon-chain and heterochain.

Carbon-chain fibers include fibers obtained from a polymer, the main macromolecular chain of which is built only from carbon atoms connected to each other. The most widely used of this group of fibers are polyacrylonitrile and polyolefin fibers. To a lesser extent, but still in relatively large quantities, fibers based on polyvinyl chloride and polyvinyl alcohol are produced. Fluorine-containing fibers are produced in limited quantities.

Heterochain fibers include fibers obtained from polymers, the main macromolecular chains of which, in addition to carbon nitrogen, contain atoms of oxygen, nitrogen or other elements. Fibers of this group - polyethylene terephthalate and polyamide - are the largest in volume of all chemical fibers. Polyurethane fibers are produced in relatively small volumes.

Particularly noteworthy is the group of high-strength, high-modulus fibers for technical purposes - carbon, obtained from graphitized or charred polymers, glass, metal, or fibers obtained from metal nitrides or carbides. These fibers are used primarily for making reinforced plastics and other structural materials.

Chemical fiber quality management

Chemical fibers often have high tensile strength [up to 1200 MN/m2 (120 kgf/mm2)], which means elongation at break, good dimensional stability, crease resistance, high resistance to repeated and alternating loads, resistance to light, moisture, mold, bacteria, chemical and heat resistance. The physicomechanical and physicochemical properties of chemical fibers can be changed in the processes of spinning, drawing, finishing and heat treatment, as well as by modifying both the feedstock (polymer) and the fiber itself. This makes it possible to create chemical fibers with a variety of textile and other properties even from one initial fiber-forming polymer. Man-made fibers can be used in blends with natural fibers in the manufacture of new ranges of textiles, significantly improving the quality and appearance of the latter.

Technological process for producing chemical fibers

The technological process for the production of chemical fibers usually includes three stages. The only exception is the production of polyamide, polyethylene terephthalate and some other fibers, where process begins with the synthesis of a fiber-forming polymer.

The first stage of the process is the production of a spinning solution or melt. At this stage, the initial polymer is transferred to a viscous-flow state by dissolution or melting. In some cases (preparation of PVA fibers), the transfer of the polymer into a viscous-flow state also occurs as a result of plasticization. The resulting spinning solution or melt is mixed and purified (filtration, deairing). At this stage, to impart certain properties to the fibers, various additives (thermal stabilizers, dyes, matting substances, etc.) are sometimes introduced into the spinning solution or melt.

"Production of chemical fibers. Properties of chemical fibers"

Goals and objectives:

1. Give an idea of ​​the types of chemical fibers and the production of fabrics from them.

2. Teach to understand the properties of fabrics and apply this knowledge in life.

3. Foster practicality and promote the development of aesthetic taste.

Lesson type: learning new material.

I. Organizational moment.

Checking readiness for the lesson.

Preparing students to perceive the lesson.

Lesson topic message.

II. Learning new material.
Verbal and illustrative story.
Today we will get acquainted with chemical fibers, their production and classification, the properties of fabrics made from chemical fibers and the method of using such fabrics.

You are already familiar with materials made from natural fibers - cotton, linen, wool, silk.
In the production of fabric, people for many centuries used the fibers that nature gave them - plant fibers, animal wool. With the development of agriculture, people began to grow cotton and flax, which provide good and durable fiber. But natural fibers are not strong enough and require complex technological processing. And people began to look for cheaper raw materials to make fabric.
In the modern world, more and more fabrics are made from chemical fiber. Rarely in the wardrobe modern man you can find something made only from natural fiber. Nowadays almost everything natural fabrics contain additives that improve their properties. Chemical textile fibers are obtained by processing raw materials of different origins.

On this basis they are divided into two groups:

Artificial (viscose, acetate, copper-ammonia);

Synthetic (polyester, polyamide, polyacrylonitrile, elastane).

The production of chemical fibers is divided into three stages

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.

The picture shows a centrifugal spinning machine, where

1- centrifuge,
2 - die.

And the die itself schematically looks like this:

1 - spinning solution,
2 - die,
3 - fibers.

When molded from a solution according to wet In this method, the streams enter the solution of the precipitation bath, where the polymer is released into the thinnest threads.

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

(video video)

III. Determination of the composition of fabrics by their properties.

"Table of properties of chemical fibers"

Work progress

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

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

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

Take 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.

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.

V. Lesson summary

Consolidation of the studied material.

Test

1. Artificial silk fiber is a fiber:

a) chemical;

b) synthetic.

2. Artificial fibers include the following fibers:

a) viscose;

b) polyamide;

c) acetate;

d) polyester;

3. Synthetic fibers are obtained:

a) made of wood;

b) oil;

c) plants.

4. You can determine the fibrous composition of the fabric:

a) by the color of the fabric;

b) combustion test;

c) appearance;

d) to the touch.

5. When synthetic fiber fabric burns, the following is formed:

a) gray ash;

b) a hard dark ball;

c) a crumbling black ball.

6. The hygienic properties of fabrics are better:

a) made of cotton fiber;

b) viscose fiber;

c) polyacrylonitrile fiber.

7. Which fabrics are highly hygroscopic and breathable?

a) natural

b) artificial

Keys

4-a,c,d

F. And _______________________________________________________ class_______

Found out ________________________________________________________________________________________________________________________________________________________________

I want to know ________________________________________________________________________________________________________________________________________________________________

F. And _______________________________________________________ class_______

Found out ________________________________________________________________________________________________________________________________________________________________

I want to know ________________________________________________________________________________________________________________________________________________________________

F. And _______________________________________________________ class_______

Found out ________________________________________________________________________________________________________________________________________________________________

I want to know ________________________________________________________________________________________________________________________________________________________________

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:

1. 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.
2. 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 connected on spinning machines into one common thread, pulled out and wound onto a bobbin.
3. 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.

Security questions

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