Spinning

Spinning: Spinning is three types. These are:
1.     Melt spinning.
2.     Dry spinning.
3.     Wet spinning.
Melt Spinning: The process of spinning by which fiber or filament is produced from melted polymer chips by extruding though spinning continuous filament produced here.

melt spinning process

Requirements:
1.     The polymer should not be volatile.
2.     The melting point of polymer should be 30ÂșC less than its decomposition temperature.
Advantage:
1.     Can be used for both staple and continuous filament.
2.     Direct and simple process.
3.     No environment pollution.
4.     High production speed (2500-3000) ft/min.
5.     Low investment cost.
Disadvantage:
1.     Required more proper maintained of machine.
2.     Heat of input is high.
Dry spinning: In dry spinning the fiber forming polymer dissolved in a volatile solvent is introduced into a heated chamber where the solvent is evaporated and solid fiber is obtained through spinneret.
dry spinning process

Dry spinning solvent:
Fiber
Solvent
Cellulose
acetone+(2-6)%water
Triacetate
Methylene chloride40%+methyl formide10%
Poly
di-methyl formamide or di-methyl acctamide
Spandex
DMF, DMAC
Modacryloic
Acetone
Properties of solvent:
1.     It should be volatile
2.     It should be organic
3.     It should have low boiling temp
4.     It should have comparatively cheap
5.     It should be non-toxic
Wet spinning process:
wet spinning process

Advantage:
1.     suitable for staple fiber
2.     Low temp required
3.     Both organic & inorganic solvent can be used
Disadvantage:
1.     Slow production (150-200ft/min) speed                                     
2.     washing of fiber are needed
3.     Toxic

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