WEEK 2
CLASSES AND PROPERTIES OF FIBRES
Fibres are classified into two main classes. Namely;

  1. The natural fibres; which are gotten from either plant e.g cotton and linen; or from animals e.g wool and silk.
  2. The man-made fibres; which are gotten from cellulose based fibres e.g viscose rayon and acetate or from non-cellulose based e.g nylon, polyester and acrylics.

PROPERTIES OF FIBRES
A. COTTON: Cotton is a vegetable fibre. It is made from cotton balls of the cotton plant. The cotton fibres surround the seeds of the cotton plant.
PROPERTIES OF COTTON

  1. It absorbs moisture quickly
  2. It is reasonably strong and durable
  3. It washes well
  4. It can be dyed easily
  5. It is cool and comfortable to wear.

B. LINEN: Is a vegetable fibre. It is gotten from the stem of flax plant. The flax plant grows in countries such as France, Russia, it is not produced in Nigeria.
PROPERTIES

  1. It is stronger than cotton
  2. It is absorbent and cool to wear
  3. It dries slowly
  4. It washes well
  5. It is a good conductor of heat.

C. WOOL; is an animal fibre. It is gotten from the hair of fleece f sheep. The hair of camel, Angora, rabbit or angora goat can also be used. It is commonly produced in Britain, Australia e.t.c.
PROPERTIES

  1. A wool fibre has a scaly appearance
  2. It is stronger when dry than when wet.
  3. It gives the smell of burning feather when burnt.
  4. It makes a very absorbent fabrics
  5. It is readily affected by bleach

D. SILK; is an animal fibre. It is produced by silk worm. Silk is produced chiefly in France, Italy, China and Japan.
PROPERTIES

  1. It is a very strong fibre
  2. It is smooth and fine
  3. It is warm to touch
  4. It absorbs moisture easily
  5. It is an expensive fibre

E. VISCOSE RAYON; is made by treating wood pulp or cotton linters with certain chemicals
PROPERTIES

  1. It is not very strong especially when wet
  2. 2. it has smooth surface
  3. 3. resemble sink in appearance only

F. ACETATE; it is made from wood pulp or cotton linters treated with acetic and acid acetic anhydride
PROPERTIES

  1. it dries quickly
  2. it looses strength when wet

 G. NYLON; is the family name for all synthetic polyamides
PROPERTIES
1.It is very strong
2. It is light in weight
3. It requires no ironing
4. It is durable.
MANUFACTURING PROCESS OF FIBRES
A COTTON; are processed from bolls by the following steps;

  1. Ginning
  2. Baling
  3. Clearing
  4. Carding
  5. Combing
  6. Drawing
  7. Spinning
  8. Dyeing
  9. Weaving

B. LINEN; Is produced from the stem of flax plant by the following steps

  1. Retting
  2. Breaking and scotching
  3. Combing
  4. Spinning

C. WOOL; wool fibres are produced into two forms

  1. Worsted yarn; this is made from long fibres
  2. Woollen yarn; this is made from short fibres

The major steps for the manufacturing of both forms are;

  1. Clipping
  2. Sorting
  3. Scouring
  4. Carbonizing
  5. Carding
  6. Spinning
  7. Weaving

D. RAYON

  1. The cellulose (wood pulp or cotton linters) is first purified
  2. The cellulose is then treated with the right chemicals. It is then changed into a thin liquid.
  3. The liquid is then forced through a nozzle containing many fine holes called a spinneret. The rayon filaments or fibres are produced
  4. The filaments are spun into yarns. The yarns are woven into fabric

Assignment
Outline the manufacturing process of the following

  1. Silk
  2. Nylon
  3. Acetate.

 EXPERIMENT AND TEST ON DIFFERENT FIBRES

FIBRESAPPEARANCE TESTMICROSCOPIC TESTBURNING TEST
COTTONIt is cool to feel and fairly firm
It has a dull appearance
Fibre is flat
Has a twist characteristics
Resembles a twisted ribbon
Burns in and out of flame
Smells like burning paper
Leaves very little grey or white powdery ash
LINENIt has a cool crisp handle
Dull appearance
fibre is round and smooth with swellings or nodes at intervalSimilar to cotton
WOOLHas a projecting fibre
Rough and dull appearance
Warm to handle
Wool fibre is covered with scales that overlap and point towards the top of the fibreDoes not burn but smoulders(i.e it burns slowly
producing smoke but not flames
Gives smell of burning hair or feathers
SILKHas a smooth and rich lustrous appearance
Soft, smooth and resilient to harm
De-gummed fibre is very fine and has a smooth surface
Raw silk fibres are seen as double filamentss
Similar to wool
VISCOSE RAYONhas a smooth fairly soft handle
A smooth lustrous appearance
It may resemble silk
Fibre is rounded with groves running length-wise
It looks like transparent rods streaked with wavy line
Similar to cotton
ACETATEIs silk-like and it drapes well
Has smooth and soft handle
Maybe dull or lustrous
Fibre is rounded with one or more surface ridges which look like thickened linesBurns like cotton and gives a smell of
acetic acid or vinegar
Smell like boiling celery
NYLONFabric is very smooth and slipperyFilament looks like a smooth glass rodShrinks like flame and melts into hard white or
grey or bead.

 

Leave a Reply

Your email address will not be published. Required fields are marked *