Patent ID: 6606901
Filing Date: 2003-08-19
Classification: G01N

Abstract:
A process for producing fibers having a minimum amount of adhering acid or base comprising:extruding a fiber-forming polymer through the orifices of a spinneret to form a fiber, preparing a washing solution, including determining an acidity of the washing solution by carrying out a combination of at least two different analytical methods, at least one of which is selected from the group consisting of density measurements, conductivity measurements, ultrasonic sound measurements, and refractive index measurements, and correcting the acidity of the washing solution to a necessary acidity value following the determining step if the acidity determined is different from the necessary acidity value, thereby deriving the washing solution having the acidity value necessary for yielding the fiber having a minimum amount of adhering acid or base following washing of the fiber with the washing solution, and washing the fiber with the washing solution to remove adhering acid or base from the fiber.