Several commonly used spinning methods for chemical fibers Melt spinning: the polymer is heated to the appropriate temperature above the melting point to prepare the melt, the melt is pressed out of the spinneret hole by the screw extruder, so that it forms a fine flow into the air, and becomes a thin strip by condensation. Solution spinning: Select the appropriate solvent, dissolve the fiber forming polymer into spinning solution, or first make the polymer into a soluble intermediate, and then dissolve into spinning solution, and then spin. Viscose, vinylon and acrylic are mostly used in this method. Solution spinning can be divided into wet spinning and dry spinning according to different solidification conditions. Dry spinning: The use of volatile solvents to dissolve high polymer to make a viscous liquid suitable for spinning. The spinning mucus is pressed out from the spinneret to form a filament flow, and the solvent in the filament flow is quickly evaporated and solidified through the hot air sleeve, and the filament is formed by drawing. (PVC, Acrylic, Vinylon, acetate) Wet spinning method: the fiber forming polymer is dissolved in solvent to make spinning solution, and the spinning solution is ejected by the spinneret into the coagulation bath. Due to the diffusion of solvent in the viscous filament stream and the penetration of coagulant into the viscous filament stream, the filament stream solidifies into filament strips. Wet spinning is characterized by a large number of spinneret holes, but the spinning speed is slow, which is suitable for spinning short fibers, while dry spinning is suitable for spinning filament. Usually the same variety of chemical fibers are more homogeneous in structure and better in quality when spun by dry spinning than by wet spinning.