Abstract: This invention relates to processes for the production of mono- and multifilaments and also staple fibers of multifilaments based on polyarylene sulfides, preferably substantially linear polyarylene sulfides and, more preferably, substantially linear poly-p-phenylene sulfide by melt spinning, multistage stretching and optionally crimping and setting.As a result of the treatment by blowing of air onto the stabilized spun filaments in the first stretching stages at temperatures .ltoreq.100.degree. C. (preferably in stretching baths, more particularly in boiling water), the chain molecules are oriented; the orientation and crystallinity required for high strengths is achieved by afterstretching (in hot air) at elevated temperature.

Abstract: Processes for the production of mono- and multifilaments and also staple fibers of multifilaments based on polyarylene sulfides by melt spinning, multistage stretching and setting. As a result of the treatment by blowing of air onto the stabilized spun filaments in the first stretching stages at temperatures .ltoreq.100.degree. C., the chain molecules are oriented; the orientation and crystallinity required for high strengths is achieved by afterstretching at elevated temperature. The residence times in the first stage required for effective stretching can only be varied within relatively narrow limits in order subsequently to achieve the calculated orientations and effects. Overly long residence times at temperatures above 100.degree. C. result in elongation of the material with no additional orientation and hence with an inadequate increase in strength.