Dryspun

Dryspun refers to fibers produced by the dry spinning process, in which a polymer solution is extruded from a spinneret into air and the solvent rapidly evaporates to form solid filaments. The filaments then travel through a drying or air-gap chamber before being wound. This method is contrasted with wet spinning, where the dope enters a coagulation bath, and with melt spinning, which uses molten polymer without a solvent.

In a typical dry-spinning setup, a dope containing a soluble polymer and a volatile solvent is prepared and filtered, then pumped through spinnerets. The extruded fibers pass through an air gap or drying chamber where solvent loss solidifies the filaments. The resulting fibers are wound onto take-up spools or further processed into tow, texturing, or blending operations. Dry spinning is suitable for polymers that dissolve in volatile, easily removable solvents and that retain fibrous integrity as the solvent evaporates.

Common materials used in dry spinning include cellulose acetate and certain other synthetic polymers that form continuous filaments from solution. The method enables fine-diameter fibers with smooth surfaces and is applicable to textiles, filtration media, and specialty fibers. However, dry spinning involves handling volatile organic solvents, requiring solvent recovery, proper ventilation, and safety controls. Economic and environmental considerations, as well as solvent selection, influence the feasibility of dry spinning for a given polymer.

Historically, dry spinning became prominent in the production of acetate fibers in the early to mid-20th century and remains in use for specific polymers and niche applications, where solvent-based fiber formation offers advantages over alternative methods.