<< Chapter < Page Chapter >> Page >

Technology

Grade 7

Processing: textiles

Module 17

The textile industry

  1. The history of the textile industry

The textile industry came into existence when people discovered that the cover of hair from some animals (e.g. the sheep) could be used without slaughtering the animal. A method for using these fibres was then developed, through spinning them together to make yarn. The fibrous nature of some plants, like the flax plant, also made it possible to spin threads which could be woven into fabric.

Today, most fabrics are knitted or woven. Fibres that are used may be natural and may be obtained from plants or animals.

Fibres may also be synthetic (produced artificially). Such textiles are produced from minerals like coal and petroleum. Examples of artificial fibres are nylon, acrylic and polyester fibres. Sometimes artificial fibres are combined with natural fibres. In this way we, for example, obtain polyester cotton.

See how many garment labels that indicate that polyester-cotton was used for the manufacture of the fabric you can find.

  1. Qualities of fibres

The length, density, strength, fineness and elasticity, as well as resistance to chemicals and moisture, determine the quality of the textile that is manufactured from a fibre. In this way, the qualities of the different types of fibres will determine the qualities of the fabrics that are made from them. The way in which fibres are knitted or woven also plays a role.

That is why a garment should have a label to describe the textile from which it is made, as well as give guidelines about how the garment should be taken care of or washed.

Study the following examples of such labels and talk about them in your groups:

  1. Doing research on the different clothing fabrics

Assignment 1:

[lo 1.1]

  • Study the labels from 3 garments and complete the table that follows:
Garment Description of textile Washing instructions Texture of fabric Fabric mass Elasticity of fabric
E.g.: T-shirt 100% cotton Cold wash hand wash Soft Light Not much

Because different types of fabric have different qualities, people choose different types of textiles for specific purposes. Soft fabrics are usually selected for garments that will be worn against the body, while other fabrics are needed for warm jerseys and jackets.

  • The following table presents a summary of the qualities of different types of fibres and also indicates how articles made from these fibres should be taken care of.
Fibre Qualities Care
Cotton CoolCan absorb moistureLittle elasticityCreases easilyVery flammableSoft/coarse, depending on weave Machine or hand wash / LukewarmRinse thoroughlyHang up to dry or spin dry. Coloured cotton is faded by the sunIron with warm ironWhites may be bleached
Wool Keeps in warmthElasticWeak when wetCan shrink Does not crease easily Dry clean / Hand washDry in shade / Lay down flatAvoid ironing, or cool iron
Artificial fibres StrongDo not absorb moistureDry easilyCrease resistantDo nor shrink or stretch (Lycra is an exception)Melts at high temperatures Warm wash- machine or handHang up or spin dryDoes not need ironing
  • Make use of the information you have gathered to select a suitable fabric for:
  • a school shirt
  • a winter jacket
  • long trousers for a boy
  • Fabric qualities:

Follow the instructions and draw up a table to record your observations.

  1. Durability :

Choose three different types of fabric. You need to be reasonably sure that you know what fibres were used during the manufacturing process.

  • Stretch the fabric over the open end of a tin and secure it in position with an elastic band.
  • Rub a stone against the fabric, using even movements until a hole is formed.
  • Compare the strength of the different fibres.
  • Flammability :

Take the same pieces of fabric and hold them close to a flame. What do you observe?

  1. Absorption of moisture :

Place the fabrics in water to see which one absorbs water most easily.

Place the wet fabric outside to see which one dries the fastest.

Fabric 1. 2. 3.
Fibres
Durability
Flammability
Absorption of moisture

Assessment

LO 2
TECHNOLOGICAL KNOWLEDGE AND UNDERSTANDINGThe learner will be able to understand and apply relevant technological knowledge ethically and responsibly.
Assessment Standards(ASs)
We know this when the learner:
Structures :2.1 demonstrates knowledge and understanding of structures.

Questions & Answers

how does the planets on our solar system orbit
cheten Reply
how many Messier objects are there in space
satish Reply
did you g8ve certificate
Richard Reply
what are astronomy
Issan Reply
Astronomy (from Ancient Greek ἀστρονομία (astronomía) 'science that studies the laws of the stars') is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution.
Rafael
vjuvu
Elgoog
what is big bang theory?
Rosemary
what type of activity astronomer do?
Rosemary
No
Richard
the big bang theory is a theory which states that all matter was compressed together in one place the matter got so unstable it exploded releasing All its contents in the form of hydrogen
Roaul
I want to be an astronomer. That's my dream
Astrit
Who named the the whole galaxy?
Shola Reply
solar Univers
GPOWER
what is space
Richard
what is the dark matter
Richard
what are the factors upon which the atmosphere is stratified
Nicholas Reply
is the big bang the sun
Folakemi Reply
no
Sokak
bigbang is the beginning of the universe
Sokak
but thats just a theory
Sokak
nothing will happen, don't worry brother.
Vansh
what does comet means
GANGAIN Reply
these are Rocky substances between mars and jupiter
GANGAIN
Comets are cosmic snowballs of frozen gases , rock and dust that orbit the sun. They are mostly found between the orbits of Venus and Mercury.
Aarya
hllo
John
hi
John
qt rrt
John
r u there
John
hey can anyone guide me abt international astronomy olympiad
sahil
how can we learn right and true ?
Govinda Reply
why the moon is always appear in an elliptical shape
Gatjuol Reply
Because when astroid hit the Earth then a piece of elliptical shape of the earth was separated which is now called moon.
Hemen
what's see level?
lidiya Reply
Did you mean eye sight or sea level
Minal
oh sorry it's sea level
lidiya
according to the theory of astronomers why the moon is always appear in an elliptical orbit?
Gatjuol
hi !!! I am new in astronomy.... I have so many questions in mind .... all of scientists of the word they just give opinion only. but they never think true or false ... i respect all of them... I believes whole universe depending on true ...থিউরি
Govinda
hello
Jackson
hi
Elyana
we're all stars and galaxies a part of sun. how can science prove thx with respect old ancient times picture or books..or anything with respect to present time .but we r a part of that universe
w astronomy and cosmology!
Michele
another theory of universe except big ban
Albash Reply
how was universe born
Asmit Reply
there many theory to born universe but what is the reality of big bang theory to born universe
Asmit
what is the exact value of π?
Nagalakshmi
by big bang
universal
there are many theories regarding this it's on you believe any theory that you think is true ex. eternal inflation theory, oscillation model theory, multiple universe theory the big bang theory etc.
Aarya
I think after Big Bang!
Michele
from where on earth could u observe all the stars during the during the course of an year
Karuna Reply
I think it couldn't possible on earth
Nagalakshmi
in this time i don't Know
Michele
is that so. the question was in the end of this chapter
Karuna
in theory, you could see them all from the equator (though over the course of a year, not at pne time). stars are measured in "declination", which is how far N or S of the equator (90* to -90*). Polaris is the North star, and is ALMOST 90* (+89*). So it would just barely creep over the horizon.
Christopher
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Technology grade 7. OpenStax CNX. Sep 10, 2009 Download for free at http://cnx.org/content/col11032/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Technology grade 7' conversation and receive update notifications?

Ask