Melt spun fluoropolymeric fibers and process for producing them

A fluoropolymer fiber exhibiting a tensile strength of at least 190 MPa and a linear shrinkage of less than 15% at a temperature in the range of 40-60 centigrade degrees below the melting point of the copolymer produced by the process comprising melting and extruding a perfluorinated thermoplastic copolymer of TFE and a comonomer selected from the group consisting of perfluoro-olefins having at least three carbon atoms, perfluoro(alkyl vinyl) ethers, and mixtures thereof, having a melt flow rate of about 1 to about 30 g/10 min., through an aperture to form one or more strands, directing the thus extruded strand or strands through a quench zone, accelerating the linear rate of progression of the strand or strands to at least 1000 times greater than the linear rate of extrusion thereof, and allowing the extrudate to solidify in transit between the extrusion aperture and a means for imposing said acceleration.

A fluoropolymer fiber exhibiting a tensile strength of at least 190 MPa and a linear shrinkage of less than 15% at a temperature in the range of 40-60 centigrade degrees below the melting point of the copolymer produced by the process comprising melting and extruding a perfluorinated thermoplastic copolymer of tetrafluoroethylene and a comonomer selected from the group consisting of perfluoro-olefins having at least three carbon atoms, perfluoro(alkyl vinyl) ethers, and mixtures thereof, having a melt flow rate of about 1 to about 6 g/10 min., through an aperture, to form one or more strands, directing the thus extruded strand or strands through a quench zone while accelerating the linear rate of progression of the strand or strands to at least 500 times greater than the linear rate of extrusion thereof, allowing the extrudate to solidify in transit between the extrusion aperture and a means for imposing said acceleration.