Difference between natural and man made fibres

Objective:

Differentiate between natural and man-made fibres.  

The Theory:

There are numerous variety of clothing material or fabric available such as, cotton, silk, wool and polyester. These fabrics are made from thin strands of thread known as yarns, which in turn are made from still thinner strands called fibres. There are mainly two types of fibres: Natural fibres and synthetic or man-made fibres.

Natural fibres:

  • The fibres that are obtained from nature are called natural fibre.  
  • Based on their source of origin, the natural fibre can be plant based (cotton, jute, linen, hemp) or animal based (silk, wool, cashmere).  
  • They generally have less strength and durability than synthetic fibres.  
  • Natural fibre are biodegradable.  
  • They provide greater breathability than man made or synthetic fibres. 
  • The fabric made from natural fibre is comfortable and good for health. 
  • Natural fibres in general are expensive.  

Man-made or artificial fibres:

  • The fibres which are developed by man are called man-made fibre. They are produced either purely chemically or by modifying natural fibres by chemical means in the industry.  
  • They are also known as artificial or synthetic fibres.  
  • For example: Polyester, acrylic, rayon, nylon and acetate.  
  • These fibres show more strength and durability.  
  • Manmade fibres are favorable for finishing. 
  • It is cheaper. 
  • The uses of synthetic fibres span from the production of numerous domestic items like ropes, buckets, furniture, containers, etc. to highly specialised uses in aircraft, ships, spacecraft, and other industries like healthcare. Parachutes are made from synthetic fibres, particularly nylon, as it is very strong and light in weight.  

Sometimes the fabric available in the market are blend of two or more fibres as such they will show characteristics of each of them. The burning test is a simple way to identify and distinguish natural and artificial fibres. The fibres which are converted into ash on burning are natural fibres and those which melt and form a bead before burning are man-made fibres. Listed below are some of the characteristic feature shown by few fibres.

Cotton:

  • Natural cellulose fibre. 
  • Burns, doesn’t melt. 
  • You will have to extinguish the flame. 
  • Burns with a bright yellow flame. 
  • We can see the afterglow. 
  • Catches fire easily. 
  • Smells like burning paper or wood. 
  • Residue: Fine gray ash. 

Rayon:

  • Artificial cellulose fibre. 
  • Burns, doesn’t melt. 
  • Burns with a bright yellow flame. 
  • Catches fire easily. 
  • Smells like burning wood or paper. 
  • Residue: Fine grey ash feels soft on touch. 

Linen:

  • Natural fibre made from flax plant. 
  • Similar to cotton (same source) only difference visually. 
  • Maintains shape on burning fine ash when touched. 

Wool:

  • Natural protein fibre. 
  • Burns, doesn’t melt. 
  • Does not catch fire easily. 
  • Stops burning when removed from fire. They are self-extinguishing materials.  
  • Smells like burning hair. 
  • Residue: Black hollow bead that can be crushed to black powder. 

Silk:

  • Natural protein fibre. 
  • Burns, doesn’t melt. 
  • Does not catch fire easily. 
  • Stops burning when removed from fire. 
  • Residue: Black hollow bead that can be crushed to black powder. 

Nylon:

  • Artificial fibre. 
  • Shrinks from heat, melts, burns, can drip. 
  • Black smoke. 
  • Smells chemical, sweet. 
  • Residue: Hard cream or black coloured bead that cannot be crushed. 

Acrylic:

  • Artificial fibre.  
  • Substitute for wool.  
  • Shrinks from heat, melts and burns (molten substance can drop).
  • Acrid smell.  
  • Sputters when burning.  
  • Residue: Hard black coloured bead that can be partially crushed.  

Acetate:

  • Artificial fibre. 
  • Shrinks from heat, melts and burns. 
  • Smells like burning cellulosic fibre with a bit of vinegar. 
  • Residue: Hard black bead that can be partially crushed.

Learning Outcomes:

  1. Students learn about the different types of fibres. 
  2. Students learn to distinguish between natural and man-made fibres.