Spinning Processes of Man Made Fibers

Melt Spinning Process

{getToc} $title={Table of Contents}

Melt Spinning Process

1. Melt SPG is used for polymers that can be melted easily.
2. Polymer is converted to a liquid just by heating its chips or pellets of it.
3. The molten polymer is pumped through the spinneret and extruded as filaments or hardened into solid filaments.
4. Nylon, polyester, and polypropylene are melt-spun.
5. The molten fibers are cooled, solidified, and collected on a take-up wheel.
6. Stretching of fibers in both the molten and solid states provides an orientation of polymer chains along the fiber axis.
7. To reduce the molt decomposition, antioxidants are used.

Dry Spinning Process

Dry Spinning Process

1. The fiber-forming substance is dissolved in a solvent before the solution is extruded.
2. The solvent can be evaporated.
3. As the jet of a solution emerges from the spinneret, a stream of hot air causes the solvent to evaporate from the SPG solution.
4. Acetate, triacetate, and acrylic are dry spun.

Wet Spinning Process

Wet Spinning Process

1. It is used when the solvent cannot be evaporated and must be removed by chemical treatment.
2. The solution of fiber-forming material is extruded into a coagulating bath that causes the jets to harden as a result of chemical or physical change.
3. Viscose fiber is wet spun.
4. The solution of cellulose xanthate is extruded into an aqueous solution of acids and salts, in which the cellulose is regenerated to form regenerated solid filaments.

Electro Spinning Process

Electro Spinning Process

1. A solution of polymer is pumped at a constant rate through a very fine orifice at the tip of a syringe towards a conductive collector plate at an optimal distance (15-30 cm).
2. A high voltage of about (15-25 kV) is applied between the tip of the needle to form a continuously changed jet of fluid that emerges from the syringe.