What is gel spinning?
Gel spinning is also called semi-melt spinning. In gel spinning method, those fibers are produced which have higher strength and high elastic properties. Gel spinning methods also increase the fiber’s molecular weight, degree of orientation, crystallinity and fibre.
The polymers are not converted into true liquid state when they are put into spinneret. When the polymer solution or plasticised gel are extruded from the spinneret, the filaments are cooled in water or solvent.
After this, they are stretched using ultra high extension and are converted into gel fibers. Due to this strong inter-chain forces are produced in the resulting filaments, this helps to increase the tensile strength of the fibers. During extrusion, the liquid crystals in polymers are aligned along the fiber axis, due to this the fibers have a relatively higher degree of orientation relative to each other, this increases the strength of the resultant filament. Since the filaments are first passed through air and then they are cooled by a liquid medium, hence sometimes this method is also called dry-wet spinning. Fibers like high-strength polyethylene and aramid fibers are usually produced using gel spinning methods.