Man made fibre and their production process

Man made fibre production and their chemical structure

1. Man-Made Fibres All fibre forming process involves following principles: Formation of polymer either by (a) Regeneration from the natural sources in case of regenerated fibres, by extraction and purification or (b) Polymerization from the monomer in case of synthetic fibres. Formation of the fibre from the polymer. (a) For example, the wood from the spruce tree is cut and send to the mills. It contains cellulose and other impurities. So to get a pure cellulose it is purified. (b) Monomer → Polymer (Polymerization) (i) Synthesis of monomers → mono – one & mer – unit. The starting material for synthetic fibres are called monomers. The chemical/hydrocarbons extracted from petroleum, natural gas or coal tar are used as raw materials for conversion into monomers.

2. (ii) Formation Of Polymers(many + units) (Polymerization): The formation of polymers from monomers can be done by joining them together by some bonds. This process is known as polymerization. Condensation or addition polymerization according to requirement.

3. Formation of Man-Made Fibre The formation of fibres from polymers involves the following principles: (i) Reduction: of the fibre forming polymeric material to a liquid state by melting or by dissolving in a solvent or in some solubilizing agent.. (ii) Extrusion: of the liquid under pressure through fine holes or orifices in a spinerette. (iii) Rapid and continuous solidification of the extruded fine stream of liquid. The main method for fibre formation i.e., spinning are determined by the physical and chemical properties of the polymer. Owing to this, spinning can be of two types i.e., melt and solution spinning.

4. However, due to differences in solidification process , solution spinning can be further sub-divided into two types i.e., dry and wet spinning. So in general spinning can be of three types i.e., Melt Spinning Dry Spinning Wet Spinning Melt spinning can be applied to the production of filament when the polymer on melting will give a viscous liquid without decomposition. (Cool Air) Dry Spinning is applied to the polymers which do not melt and dissolve in volatile solvents.(Hot air(inert gas) drying) Wet Spinning is applied to the polymers which do not melt and dissolve only in non-volatile solvents .(Chemical bath)