A process for dispersion spinning non-melt-processible fluoropolymer fiber
in which a mixture of an aqueous dispersion of non-melt-processible
polytetrafluoroethylene or modified polytetrafluoroethylene fluoropolymer
particles and an aqueous solution of matrix polymer is formed. The non
melt-processible particles have an SSG of less than about 2.40. The
aqueous dispersion contains an aliphatic alcohol ethoxylate nonionic
surfactant having a 20% residuals temperature determined by
thermogravimetric analysis (TGA) of less than about 290.degree. C. and is
essentially free of surfactants containing aromatic groups. The
dispersion has a fluorinated surfactant content of less than about 300
ppm. The mixture is extruded into a coagulation bath containing a
concentration of ions which coagulate the matrix polymer to form an
intermediate fiber structure. The intermediate fiber structure is
sintered to decompose the matrix polymer and coalesce. The present
invention also provides a spinning composition useful for the dispersion
spinning of non-melt-processible fluoropolymer fiber.