Unit 3: Characteristics of fabrics
Key Unit Competency
To be able to understand and explain the characteristics of different fabrics and conduct appropriate experiments with them.
Learning objectives
After studying this topic, I should be able to:
• Identify different fabrics.
• Classify different fabrics.
• Explain characteristics of fabrics.
• Experiment on fabric textures.
Introduction
Look at the pictures below. What kinds of clothes are they? Are they important or not?
What kind of material do you think each of them is made of? What is the source of that material? Based on your answers above, what do you think you will learn in this unit?
3.1 Classification of fabrics
We wear different types of clothes. The fabrics that make these clothes are made from different types of fibres. The fibres can either be natural or synthetic. The characteristics of the different fabrics are determined by the origin of the fibres it is made from.
Activity 3.1
Put the clothes or pieces of clothes provided by your teacher into different groups. How many groups did you come up with? What factors did you consider when coming up with the groups? Draw a fl ow-chart to show the groups that you came up with. Compare your chart with Fig 3.2 on page 57.
The facts
As we have already seen, the clothes we wear are made from different fabrics. These fabrics have different characteristics. These characteristics define the uses of the fabrics. Some fabrics are heavy as compared to others.Others have a soft feel, while others are warmer than others.
Fabrics are normally classified according to the origin of their fibres. There are those that are obtained from natural materials (natural fibres) and those that are made by human beings (artificial fibres).
Fill in the table below with the correct origin of the fabrics listed (i.e. artificially made, animal or plant).
• Natural fibres – these can be obtained from animal parts, natural proteins, minerals and various plant parts such as cellulose. Cellulose is the substance that forms the cellwalls of plants. Fibres made from cellulose are referred to as cellulosic fibres. The cellulosic fibres include cotton, linen and jute. Examples of fibres obtained from animals are wool and silk. Asbestos is an example of a mineral kind of fibre.
• Artificial fibres – these are manufactured from chemicals and other substances. Examples of artificial fibres are rayon, polyamide, polyester and acrylic. Artificial fibres can be further classified into regenerated fibres and synthetic fibres. Regenerated fibres are made from treating the natural materials with chemicals. They include viscose rayon and acetate rayon. Synthetic fibres are made from chemicals.
Examples are given below.
(i) Polyamides – such as nylon and polyester such as terylene.
(ii) Acrylonitrile – such as acrylic.
(iii) Elastofibres – such as lycra.
Quality check!
When buying clothes, check that it has clear directions on care and handling. This helps in ensuring that clothes last long and remain in good condition.
1. What fabrics are common in your household?
2. Differentiate between natural and artificially made fibres.
3. (a) Which is the best fibre for babies?
(b) Explain your answer in 3(a) above.
3.2 Characteristics of different fabrics
Do you think all fabrics are of the same type? If not, what makes them different?
Activity 3.2
In this activity, you will be required to use the same clothes you had used in Activity 3.1. Try to describe their:
(a) Appearance (how they look, arrangement of fi bres, e.t.c).
(b) Texture (how they feel to touch).
Go to the library or the internet and research from textbooks about the characteristics of fabrics. Write a report and present to the rest of the class.
The facts
Each of the different fabrics we have learnt about have their own unique characteristics. Examples of fabrics whose characteristics you will learn are:
• Cotton • Wool
• Silk • Linen
• Polyester • Rayon
• Nylon
In looking at the characteristics of these fabrics, we shall consider their appearance and texture. We will also find out their care requirements.
(a) Cotton
Cotton fibre is produced from the cotton plant. When the cotton plant grows and matures, it produces cotton balls. The cotton balls are then picked and processed into yarn. The yarn is what is spun into a cotton fabric.
Examples of cotton fabrics are lawn, calico, flannelette, drill, jinja, denim, gingham, muslin, organdie, cambric, hair cord, pique, poplin, khaki, corduroy, terry toweling and voile.
Practical ways of identifying cotton
Activity 3.3
Your teacher will give you a sample of cotton. Do the following1. Touch the cotton between your fingers. How does it feel?2. Burn the sample of cotton. What happens? Is there any smell produced?3. View the sample of cotton using a microscope. Draw what you can see.4. Put the cotton sample in hydrochloric and nitric acids. What happens?i) Appearance and handle– Cotton feels strong (the fibres do not break easily).– It lacks luster.(ii) Burning testWhen burnt, cotton flares up with a yellow flame. It smells like burnt paper leaving behind grey ash-resembling wood ash.(iii) View under the microscopeWhen observed under the microscope, cotton appears like twisted threads. These twists are what make cotton fibre very strong.(iv) Solubility testCotton dissolves in hydrochloric and nitric acids.Discussion corner
Talk to your friend about the various special characteristics of clothes made of cotton. Discuss also how these clothes can be cared for.Care for cotton fabrics
Characteristics of cotton fabricWhat should we do to ensure cotton fabrics last for long?1. Avoid storing them when wet. This will cause development of mildew stains.2. Avoid exposing cotton to sunlight for too long. This causes it to degrade.3. Since it creases easily, cotton should be ironed when not completely dry.4. Cotton becomes weak when wet, hence it should not be soaked for long.The facts
• It is highly absorbent and soft to touch. Therefore, clothes made from cotton have a very high affinity to water.• It is also because of its highly absorbent nature that it readily takes in dyes. Due to this, it can be available in a wide range of colours.• It is resistant to high temperatures. This is because of its strength. Dirty clothes made out of cotton can be boiled to be sterilised.• Cotton can withstand mild alkalis, washing detergents and all kinds of stain-removing agents. Cotton clothes can hence be very easily laundered.• Cotton makes strong fibres. Hence the fabrics are strong too.• It is resistant to attacks from moths and other destructive insects.• Cotton does not generate and hold static electricity.• It is a good conductor of heat.• It catches dirt very easily.• It is not resistant to mildew. It can therefore easily get damaged if kept under damp conditions.• It lacks natural brightness (luster).• It is easily weakened by strong acids.• Cotton creases easily because of its low ability to spring back after being stretched.• It burns readily when exposed to flames.• It weakens when it is exposed to sunlight for too long.(b) Wool
Wool is obtained from the fleece of sheep. The common sheep which produces wool is the merino sheep. We can also get wool from special types of goats and rabbits.Wool is a protein fibre.Examples of woolen fabrics are tweed, mohair, gabardine, whipcord, serge, jersey, felt, woolen clothes and worsteds.Practical ways of identifying wool
Activity 3.4
Your teacher will give you a sample of wool. Do the following.1. Touch the wool between you fi ngers. How does it feel?2. Burn the sample of wool. What happens? Is there any smell produced?3. View the sample of wool using a microscope. Draw what you can see.4. Put the wool in hot caustic soda solution and sodium hypochloride bleach. What happens?The facts
(i) Appearance and handle– Wool feels hairy.– It lacks luster.(ii) Burning testWool does not burn. It smolders with a strong smell of burnt hair or feathers.(iii) View under the microscopeWhen observed under the microscope, wool has a rough and fuzzy surface.(iv) Solubility testWool dissolves in hot caustic solution and sodium hypochloride bleach.Discussion corner
Do you know about any characteristics of clothes made of wool? How should we care for them? Discuss these with your friend.The facts
Characteristics of wool• It has natural crimp hence warm.• It is highly elastic and resilient making it resistant to wrinkle.• It does not burn easily.• It is highly absorbent.• It can be attacked by moths when stored for long.• Wool easily shrinks.• Wool felts easily.• Long exposure to direct sunlight turns wool yellow.• Wool can easily stretch out of shape.• Wool is easily damaged by alkalis which is found in most laundry soaps.Care for woolWhat should we do to ensure that woolen fabrics last for long?1. Wool stretches out of shape and should not be soaked.2. It is destroyed by alkalis and so mild detergents should be used.3. It is affected by high temperatures hence care should be taken during washing and finishing.4. Should be stored well as it is affected by moths.(c) Silk
Silk is produced from the secretions of silkworms. The silkworms feed on mulberry trees. The worms secrete the silk thread.The threads are then harvested and put in hot water. The hot water helps to unwind the thread. The threads are then twisted to form yarn.Examples of silk fabrics aretaffeta, chiffon, brocade, velvet, satin, crepe de-Chine, faille, georgette, organza and silk jersey.Practical ways of identifying silk
Activity 3.5
Your teacher will give you a sample of silk fabric. Do the following:1. Touch the silk between you fi ngers. How does it feel?2. Burn the sample of silk fabric. What happens? Is there any smell produced?3. View the sample of silk fabric using a microscope. Draw what you can see.4. Put the silk fabric in sodium hypochloride bleach, hydrochloric acid, sulphuric acid and in caustic soda. What happens?The facts
(i) Appearance and handleSilk feels smooth and soft.(ii) Burning testWhen burnt, it curls and eventually burns giving off a smell of burnt hair.(ii)View under the microscopeWhen observed under a microscope, silk appears like a smooth rod-like surface with some triangular points on its length.(iv) Solubility testSilk dissolves in sodium hypochloride bleach, hydrochloric acid, sulphuric acid and in caustic soda.Discussion corner
Do you know about any characteristics of clothes made of silk? How should we care for them? Discuss these with your friend.The facts
Characteristics of silk fabric• Silk has strong fibres.• It is not flammable.• It is very lustrous (shiny and bright).• It is resistant to creasing because it has some degree of elasticity.• It has a good drape.• It has a high affinity for dyestuffs.• It makes warm fabrics.• It is resistant to mildew, fungi and moth attacks.• It is absorbent.• It is damaged by high temperatures.• Long exposure to sunlight weakens the fibre.• It is easily damaged by alkalis and acids.Care for silk
What should we do to ensure that silk fabrics last for long?1. It should be protected from high temperatures.2. It should not be bleached. Bleaching weakens silk.3. Use mild detergents.(d) Linen
Linen fibre is obtained from the stem of fl ax plants. It is a cellulosic fbre. It is from the fibres that yarn is made. The yarn is eventually used for making linen fabrics.Examples of linen fabrics are damask, crash, toweling dress and suiting fabrics, linen/polyester canvas, cambric and huckaback.Practical ways of identifying linen
Activity 3.6
Your teacher will give you a sample of linen fabric. Do the following:1. Touch the linen fabric between you fingers. How does it feel?2. Burn the sample of linen fabric. What happens? Is there any smell produced?3. View the sample of linen fabric using a microscope. Draw what you can see.4. Put the line fabric in concentrated sulphuric acid, hydrochloric acid and nitric acid. What happens?The facts
(i) Appearance and handleLinen feels rough and lustrous.(ii) Burning testLinen like cotton, fl ares up with a yellow fl ame. It smells like burnt paper, leaving behind grey ash resembling wood ash.(iii)View under the microscopeWhen observed under the microscope, linen appears like a smooth lustrous rod with nodes at intervals.(iv) Solubility testLinen dissolves in concentrated sulphuric acid, hydrochloric acid and nitric acid.Characteristics of linen
Discussion corner
Do you know about any characteristics of clothes made of linen. How do they behave under various circumstances? Discuss these with your friend. Also give ways of caring for linen clothes.The facts
The characteristics of linen are similar to those of cotton. Linen, is however much stronger than cotton. It is more lustrous, it frays more readily has crisp and is very expensive. Linen is also more resistant to damage through long exposure to sunlight.Care for linen1. Linen frays badly therefore it should be finished well.2. It should be well dried before storage to avoid formation of mildew.3. Linen is highly flammable. It should therefore be kept away from fire.(e) Nylon
This is a synthetic fibre from the polyamide family.Practical ways of identifying nylon
Activity 3.7
Your teacher will give you a sample of nylon fabric. Do the following1. Touch the nylon fabric between you fingers. How does it feel?2. Burn the sample of nylon fabric. What happens? Is there any smell produced?3. View the sample of nylon fabric using a microscope. Draw what you can see.4. Put the nylon fabric in formic acid. What happens?The facts
(i) Appearance and handle- Nylon is very smooth, soft and elastic.- It is lustrous in appearance.(ii) Burning testNylon runs away from flame and melts into a hard, uncrushable bead.(iii) View under the microscopeWhen observed under the microscope, nylon appears like a smooth glass rod.(iv) Solubility TestNylon dissolves in formic acid.Characteristics of nylon
Discussion corner
Do you know about any characteristics of clothes made of nylon. How do they behave in various circumstances? Discuss these with your friend. State also how such clothes can be cared for.The facts
• It is extremely strong, light and elastic.• It is not absorbent.• It neither shrinks nor stretches.• It is thermoplastic i.e it can be permanently pleated.• It is resistant to moth and mildew attack.• It requires little or no ironing. It is therefore an easy-care fabric.• It is crease-resistant. It can hence be blended with other fibres to improve their quality.• Nylon is a poor conductor of heat.• It is resistant to abrasion.• Pilling is common in fabrics made of spun nylon yarns.• It is versatile. Nylon fabrics can be produced in a variety of textures, thickness and finishes for various uses.• Nylon rots with long exposure to sunlight. It is therefore not suitable for making curtains.Care for nylon
How can we ensure that our nylon fabrics last for long?1. It should not be exposed to sunlight for a long time. This may cause rotting.2. It should be protected from activities that cause friction to avoid pilling.(f) Polyester
This is a man-made fibre derived from coal, air, water and petroleum. When they are mixed with other chemicals, they form polyester. It resembles nylon fabric.Examples of polyester fabrics are jersey, terylene, lawn, suiting, polyester/woolen blends, polyester/cotton blends and trevira.Practical way of identifying polyester
Activity 3.8
Your teacher will give you a sample of polyester fabric. Do the following:1. Touch the polyester fabric between you fi ngers. How does it fell?2. Burn the sample of polyester fabric. What happens? Is there any smell produced?3. View the sample of wool using a microscope. Draw what you can see.4. Put the polyester fabric in concentrated sulphuric acid. What happens?The facts
(i) Appearance and handle- Polyester is very smooth and soft. It is elastic to handle. - It is lustrous in appearance.(ii) Burning test– Polyester burns in the flame and produces an aromatic smell. – It leaves behind a hard bead.(iii) View under the microscopeLong smooth continuous fibre (similar to silk).(iv) Solubility testPolyester dissolves in concentrated sulphuric acid.Characteristics of polyester
Discussion corner
Do you know about any characteristics of clothes made of polyester? How do they behave in various circumstances? Discuss these with your friend. You should also state how clothes made of polyester can be cared for.The facts
• It is a very strong fibre both when dry and also when wet.• It is resistant to bleaches and acids.• It has a high affinity for dyes.• It can be blended with other fabrics and crimped to produce more desirable fabrics.• It is thermoplastic and can therefore be permanently pleated.• It is flame and crease resistant.• It is resistant to attacks by moths, mildew, fungi and bacteria.• It is not destroyed by strong exposure to sunlight hence, it is suitable for making curtains.• It is not absorbent. It therefore does not take up dyes easily.• Polyester is resistant to abrasion.• Stains and dirt are easily removed.• It is resistant to shrinking, creasing and stretching.Care for polyester
1. Avoid too much heat so that it does not stretch.2. Do not bleach. This weakens the fabrics.g) Rayon
There are two types of rayon; viscose rayon and acetate rayon.(i) Viscose rayonViscose rayon fabric is made from treated wood pulp. The pulp is processed into fi bre which is then spun into yarns. The yarn is then what makes the fabric.Examples of viscose rayon materials include: damask, satin and velvet, flannel, lace, taffeta, gabardine.Identification of viscose rayon
Activity 3.9
Your teacher will give you a sample of viscose rayon. Do the following1. Touch the viscose rayon between you fingers. How does it fell?2. Burn the sample of viscose rayon. What happens? Is there any smell produced?3. View the sample of viscose rayon using a microscope. Draw what you can see.4. Put the viscose rayon in acetone but it does not dissolve. What happens?i) Appearance and handle– Viscose rayon is smooth and soft.– It is lustrous in appearance.(ii) Burning testViscose rayon burns with a yellow flame leaving behind ash. It also resembles cotton.(iii) View under the microscopeWhen observed under the microscope, viscose rayon appears like wavy lines of glass.(iv) Solubility testViscose rayon dissolves in caustic soda, hot sulphuric acid and hydrochloric acid.Characteristics of viscose rayon
• It is reasonably strong.• It is absorbent and hence takes up dyes well.• It is fairly crease resistant.• Viscose is moth-proof and fairly resistant to mildew stains compared to cotton.• Yellows and rots when exposed to light for a long time.• It is weaker when wet than when it is dry. It should therefore be handled with care when being laundered.Care for viscose rayon
• Viscose is a strong fibre. It can therefore be laundered by use of a washing machine or by hand.• It is resistant to alkalis. It is therefore not damaged by detergents.Acetate rayon
Acetate rayon is made by treating cotton linters with chemicals.Practical ways of identifying acetate rayon
The facts
Activity 3.10
Your teacher will give you a sample of acetate rayon. Do the following1. Touch the acetate rayon fabric between you fingers. How does it feel?2. Burn the sample of acetate rayon fabric . What happens? Is there any smell produced?3. View the sample of acetate rayon fabric using a microscope. Draw what you can see.4. Put the acetate rayon fabric in acetone but it does not dissolve. What happens?(i) Appearance and handle– Acetate is smooth and soft to handle.– It is lustrous in appearance.(ii) Burning testBurns like viscose rayon.(iii) View under the microscopeWhen observed under the microscope, acetate rayon appears like a rounded structure-less fibre.(iv) Solubility testAcetate rayon swells in acetone but it does not dissolve. It dissolves in methylated chloride.Characteristics of acetate rayon
• It is lustrous and hence it gets to have a rich appearance.• It has a good drape.• It is soft to handle.• It can be treated to become water repellent.• It is weaker when wet than when dry.• It is resistant to moth attack and mildew. This makes its storage easy.• It cannot withstand high heat. It is therefore best for permanent pleating.• It is less absorbent than viscose rayon. It hence dries very easily.• Acetate rayon is resistant to shrinking, creasing and stretching.• It is easily damaged by strong alkalis – they weaken its luster.• It develops and holds static electricity. It hence cannot be used for making under garments.• It is soluble in acetone as it is one of its components.Care for acetate rayon
What should we do to ensure that acetate rayon lasts for long?1. Use mild detergents when washing to avoid weakening it.2. Fabric softeners should be used when rinsing water to control development of static electricity.3. Avoid subjecting it to acetone.Activity 3.11Collect various pieces of fabrics, get a microsope, sulphuric acid, hydrochloric acid, acetone and methylated chloride. Carry out these tests on the pieces of fabric:a) Microscopic testb) Solubility testc) Burning testd) Touch testFrom the tests above, group the fabrics based on the type of material they are made of. Discuss your results with other class members.1. Discuss the characteristics of natural fibres.2. Explain why wool is not commonly used in making school uniforms.3. Explain why polyester is a popular fibre in the cloth making industry.4. Discuss the properties of polyester which differentiates it from nylon and cotton.5. What are the advantages of blending various fibres together?6. Which fabrics would be most appropriate for making curtains of a house?My environment, my life!Some fabrics, especially the artificial ones, are non-biodegradable. They should therefore be disposed of properly. Let us protect our environment in order to have it tomorrow.Remember the facts!• A fibre is a long thin hair-like substance which is spun into yarns. Yarns are then used for making fabrics.• Textile fibres are classified as either natural or artificial.• Natural fibres are obtained from animal and plant parts. They include silk, wool and cellulosic or plant fibres.• Artificial fibres are mostly synthetic. They are usually regenerated in factories. Examples include viscose rayon and acetate rayon.• Synthetic fibres include polyester and nylon.• Fibres can be identified by burning, using the solubility test, observing under the microscope, by touching and also by observing the appearance.Test your competence 3
1. Explain the best fabric we should choose for making the following articles. Give reasons for your choice.a) An apron _________________ d) Curtains _____________________b) An offi cial shirt ____________ e) Chair back cover ______________c) Bed sheets ________________ f) Medical theatre clothes _________2. Fill the gaps in the following sentences.a) Cotton, linen, wool and silk are ______ fibres.b) Viscose and acetate rayon are _____ fibres.c) Nylon, polyester and acrylic are ______ fibres.3. Which fabrics are most suitable for making baby clothes?4. Why is a blanket mostly used when extinguishing fire?5. Give the advantages of synthetic fibres over natural fibres.6. Find and circle six types of fabrics from the grid below.7. Write True or False.a) Silk is smooth and shinny than cotton. _______________b) Viscose rayon is more absorbent than nylon. _______________c) Water forms stains on silk which are diffi cult to remove. _______________d) Wool is warmer than acrylics. _______________e) Polyester is warmer than nylon. _______________f) Acetate rayon dissolves in acetone. _______________8. Your sister wants to do tie and dye. Which materials would you recommend to her for use?9. A Senior 2 student had kept his pair of shorts in the wardrobe for two months without wearing it. When the time came for him to wear it, he found it with strange white markings.a) What were the white markings?b) What fabric was the short made of?10. Match the fabrics with their correct characteristics using a line.11. Which fabrics are negatively affected by bleaching?12. Which one of the following fabrics is not easily affected by burning?A. CottonB. LinenC. WoolD. Nylon13. State the effect of each of the following activities on the fabrica) Prolonged exposure of wool to the sun. _______________b) Acetone pouring on acetate rayon. _______________c) Prolonged rubbing of nylon. _______________d) Storing linen when dump. _______________e) Prolonged exposure of viscose rayon to the sun. _______________14. Which one of the following is not a characteristic of silk fibre?A. It is warm.B. It is highly lustrous.C. Easily gets water-mark stains.D. Dissolves in acetone.15. Which one of the following is not a characteristic of nylon?A. Highly absorbent.B. Appears fuzzy on the surface.C. It is strong.D. It shrinks badly.16. Choose the Odd one out.A. Nylon, polyester, acrylic.B. Cotton, wool, silk.C. Viscose rayon, acetate rayon linen.D. Cotton, nylon, wool.17. State the disadvantages of synthetic fibres.18. Collect a vaiety of old pieces of clothes. Perform various tests on them to establish which ones they are. Come up with a table on the various fabrics and their identities. Which tests did you use? How did you make your conclusion?Glossary
Abrasive: This is a term that refers to a substance that can grind or polish a hard or metallic surface by scrubbing. It is often associated with having a rough surface.Chiffon: This is a fine almost transparent fabric in plain weave of silk, wool or artificial fibres.Crepe: This term refers to light weight fabric in plain weave. It can be silk, viscose acetate, cotton, wool or polyester.Damask: This is a firm-textured fabric with a raised pattern.Denim: This term refers to a twill-woven fabric from cotton or cotton blends mainly used to make jeans.Flannel: This term refers to an all-wollen fabric made from either wooven or twisted yarns.Flannelette: A soft cloth in plain or twill weave usually made from cotton.Gingham: This is a light-weight to medium-weight fabric woven in plain weave. It may be cotton or linen.Jinja: This is plain woven cotton fabric in light-weight and medium-weight. The name originated from Jinja town in Uganda where the fabric was first produced.Lawn: Lawn refers to fine, light and crisp fabric in plain weave usually from cotton or linen. Organza: It is a thin transparent stiff fabric of cotton, viscose or silk.Sateen: This is cotton fabric or spun yarns from artificially produced fabrics with fl oats running on weft.Satin: This is silk or rayon fabric with a smooth glossy finish.Taffeta: This is a crisp, plain woven lustrious fabric of either silk or rayon fabric.Velvet: This is a cotton, silk or nylon fabric with a soft thick pile and a plain under side.