Effect of processing on electrical resistivity of textile fibers

Most test methods used to evaluate the electrostatic properties of textile materials are based, in one way or another, on the measurement of electrical resistance. Many and various methods have been devised to measure electrical resistance of textile assemblies and a diversity of parameters are used to define it. Generally speaking, it is very difficult to match results of different methods. In this paper we use, for measuring electrical resistivity of textile assemblies, a multiple-step method, which takes compressional properties of the assembly into consideration and defines a new parameter to describe electrical resistivity of textile assemblies. The new definition used for the resistivity of the textile assembly is similar to the volume resistivity of a rigid homogeneous material, being so an inherent characteristic reflecting electrical properties of fiber material, independent of sample form (fabric, yarn, fiber), dimensions of measuring cell and amount of the sample. This method made possible, for the first time, a measurement of the evolution of electrical resistivity of cotton and wool fibers during the spinning process. The results enabled the evolution of electrostatic properties of fibers to be determined as the they passed from one processing machine to the other. Thus, the intensity of processing and need for treatment with antistatic lubricants could be assessed.