What is wet spinning?
Wet spinning is known to be one of the oldest spinning processes which is also the most expensive and complex spinning process. This process can be used to produce both staple and filament types of fibers. Those polymers which do not melt and are only soluble in non-volatile or thermal unstable solvents use the wet spinning method for yarn formation.
To convert the raw material into a solution, a non-volatile liquid is used. Then the solution is forced through the spinneret by simply washing it or through a chemical reaction between the polymer solution and a reagent in the spinning bath. Since the polymer solution is directly extruded into the precipitating liquid, hence this method is called the wet spinning method because of the ‘wet’ bath used. Since the polymer solution is extruded into a solvent-non solvent mixture which is called as coagulant hence due to the mutual diffusion of solvent and non-solvent, the polymer solution coagulates to form fibers.
After which from the liquid coagulation medium, the solvent is removed and the filament yarns are wound onto bobbins or treated further to achieve desired characteristics. This process is used for manufacturing filament yarns of aramid, lyocell, PVC, vinyon (PVA), viscose rayon, spandex, acrylic, and modacrylic fibers.