SUBJECT: HOME ECONOMICS
CLASS: JSS 3
TERM: 1st TERM
TOPIC: CLASSES AND MANUFACTURE OF FABRICS
CLASSIFICATION OF FIBRES
Fibres are classified into two. These are:
- Natural fibres : These are from natural source either plant and animals
- Man-made fibres: These are man-made fibres either cellulose based or non-cellulose based.
The table below show clear classification of fibres
Natural fibres Man-made fibres
Aninmals Vegetable Cellulose Non-cellulose
fibres fibres fibres fibres
wool cotton rayon nylon
silk Linen Acetate Polyesters
IDENTIFICATION AND PROPERTIES OF FABRICS
Cotton is a vegetable fibre. It is made from cotton balls (bolls) of the cotton plant. Cotton grows in Northern parts of Nigeria, China, India, Asia, Egypt and America.
Properties or characteristics of cotton
- It absorbs moisture quickly.
- It is strong and durable.
- It washes easily.
- It is cool and comfortable for wear.
- It can withstand friction or rubbing.
- It can withstand hot water.
- It does not fray easily
- It is easy to sew.
- Cotton burns easily in flame.
- It shrinks when washed.
Linen: Linen is vegetable fibre. It is got from the stem or flax plant. The flax plant grows fast in France, Russia, and Belgium.
Properties or characteristics of Linen
- It is strong than cotton.
- It is absorbent and cool to wear.
- It dries slowly.
- It is good conduct of heat.
- It crease badly
- It washes well
- It fray badly and easily
- It burns readily
- It can withstand high temperature
- It has natural luster.
Wool: Wool is an animal fibre. It is got from the hair or fleece of sheep. The hair if a camel, Angora rabbit or goat.
Properties or characteristics of wool
- It has scaly appearance.
- It is elastic and sparingly to touch.
- It makes a very absorbent fabric.
- It is stronger when dry than wet.
- It has large number of air spaces between fibres.
- It is attacked by clothes and other insects.
- It gives smell of burning feathers when burns.
- It felt or shrinks easily when treated with hot water.
Silk: Silk is an animal fibre. It is produced by silk worm .Silk is produced chiefly in France, Italy, China and Japan.
Properties or characteristics of Silk
- It is very strong fibre.
- It is smooth and fine.
- It is springy or elastic
- It is crease-resistant.
- It is warm to touch.
- It absorbs moisture easily.
- It is easily.
- It is an expensive fibre.
- It is weak when wet.
- It gives a smell of burning feather when burnt.
Man-made or synthetic fibres: Man-made fibres are divided into two. These are
- Cellulose based fibres: Man from cellulose which is obtained from cotton linters or wood pulp .e.g. viscose rayon and acetates.
- Non-cellulose man-made fibres: Made entirely from mineral substance such as coal and petroleum. e.g. Nylon, polyester, acrylics.
Viscose rayon: Viscose rayon is made by treating wood pulp or cotton linters with certain chemicals.
Properties or characteristics of viscose rayon
- It is absorbent.
- It is soft and draper well.
- It is not very strong especially when wet.
- It is cool to wear.
- It has smooth surface.
- It dyes well.
- It is not easily attacked by mildew.
Acetate: This also is regenerated cellulose fibre. It is made from wood pulp or cotton linters.
Properties or characteristics of Acetate
- It has silk –like rich soft attractive appearance
- It is soft and drapes well.
- It is moderately elastic.
- It covers well from creasing.
- It dries quickly.
- It can be dyed in rich colours.
- It dissolves in acetone and nail polish remover.
- It is not very absorbent.
- It loose strength when wet.
Nylon: Nylon is the family name for all synthetic polyamides.
Properties or characteristics of nylon
- It resists abrasion well.
- It does not absorb much water.
- It has smooth surface.
- It is light in weight.
- It is durable
- It does not shrink
- It is often blended with wool or cotton.
- It requires no ironing.
- It is easy to wash
Polyesters: Polyesters are also product of complex series of chemical processes using petroleum products and other chemicals.
Properties or characteristics of polyesters
- They are very strong.
- They are resistant to abrasion.
- They do not strength very well.
- They are easily to wash.
- They are not harmed by heat.
- They do not dye easily.
- They are used to add strength to wool or cotton.
- They are generally warm to wear.
MANUFACTURING PROCESSES OF DIFFERENT FABRICS AND FIBRES
Manufacture of fabrics
Manufacturing process of cotton fibres
Cotton fabrics are processed from the bolls by the following processes.
- Ginning: This is the process of separating or removing cotton fibres from the seeds.
- Baling: The ginned cotton is pressed into bales before send to factory mill.
- Cleaning: This is the process of removing impurities from cotton in the mill.
- Carding: At the stage, many shorter fibres are removed to formed thick rope called silvers.
- Combing: This is the process of removing more short fibres.
- Drawing: This is the process of twisting the ropes and making them ready for spinning.
- Spinning: This is the process of making the twisted fibres into yarn or thread.
- Dying: The yarn can be bleached or dyed into different colours and woven into fabrics.
- Weaving: The yarns are used to produce fabrics.
Manufacturing process of Linen
Linen is processed from the stem of flax plant by the following processes.
- Retting: This is the process of soften the flax stems by letting the rot in ponds to separate fibres from the stem.
- Braking and scotching: These are mechanical treatments that break and removed the woody mater and impurities from fibres.
- Combing: This is the process of passing the fribres through combs to separate long fibres from short ones.
- Spinning: This is the process of drawing the fibres into silvers and twisting them for strength.
- Scotching: The process of washing the fibres in soapy alkaline water to remove dirt and grease.
- Carbonizing: The process of removing all vegetable matter from the fibres by treating them with acid heat and pressure.
- Carding : This process separate the matted fibres
- Spinning: This is the process of twisting the fibres into worsted or woolen yarns.
- Weaving: The process of making the wool fabrics from the yarn.
Manufacturing process of Silk
- Throwing: This is process of twisting silk fibres to form a strong yarn.
- De-gumming: This is the process of removing the silk gum from the yarn by boiling in soapy water.
- Weaving: This is the process of constructing the yarn into silk fabric.
Manufacturing processes of rayon
- The cellulose is first purified.
- The cellulose is then treated with the right chemicals .It is then changed into a thick liquid.
- The liquid is then forced through a nozzle containing many fine holes called spinner.
- The filaments are spun into yarn .The yarns are woven into fabric
Manufacturing process of acetate
- The cellulose is purified
- It is treated with acetic acid and acetic anhydride.
- Cellulose acetate is dissolved into acetone to form a thick liquid.
- The liquid is spun into filament or fibres.
Manufacturing process of nylon
Nylon is made through a complex series of chemical processes, using coal or petroleum, water and air .It can be made into continuous filaments or short length (staple yarn)