The method of manufacturing polytetrafluoroethylene fibers, and polytetrafluoroethylene fibers

The present invention provides a method for producing a PTFE fiber that makes it possible, unlike the emulsion spinning process, to obtain a polytetrafluoroethylene (PTFE) fiber, particularly a long PTFE fiber, without using a matrix material, is more productive than conventional production methods such as a slit yarn process, and is capable of enhancing mechanical properties and the degree of freedom in diameter of the obtained fiber. The method for producing the PTFE fiber of the present invention includes the step of reducing a diameter of a string-shape PTFE-containing solid material (a first solid material) by drawing the first solid material at a temperature equal to or higher than a melting point of PTFE. The first solid material can be obtained from a PTFE-containing solid material (a second solid material) containing water and a surfactant, by reducing an amount of the water contained in the second solid material.