Single Cotton Fiber Diameter Determination by Using Fraunhofer Diffraction

An optical approach based on the principle of Fraunhofer diffraction is developed to measure the diameter of single cotton fibers.  Various cotton fiber quality parameters such as short fiber content, fiber breakage, fineness, and micronaire are correlated to the diameter of the single fibers measured.  The objective of this work is to conduct a fundamental study of the optical properties (diffraction, light scattering) of individual cotton fibers with the interaction of a 0.8mW polarized He-Ne laser beam with a nominal wavelength of 633nm.  Diffraction patterns produced are captured by a line CCD and are analyzed to determine the diameter of the single cotton fibers. A correlation is made between the measured diameter and the aforementioned cotton fiber quality parameters.  This approach can be used as a calibration method for existing cotton fiber measurements systems such as AFIS and HVI to provide a better characterization of cotton fiber quality.