Search

A method based on analysis of angular diagrams of light backscattering is proposed for the determination of the direction of yarn twist. The efficiency of this method is proved by the example of the study of yarns with various fibre compositions and with various twist counts.

This paper proposes a noninstrumental method of monitoring the angular distribution of the fibers in fiber-containing materials (FCMs) such as paper, semifinished textile products, and similar materials, based on a computer calculation of the Fraunhofer diffraction pattern using computer microimaging of the surface of the FCM, corrected for illumination by a laser light beam. An algorithm is proposed for the computer processing of the diffraction pattern thus constructed, with output to an angular light-scattering diagram, from which the angular distribution of the fibers in the material can be judged. Our experiments on semifinished textile products and paper showed that the proposed method is workable and that it has an advantage over an analog method of monitoring, using the angular diagram of the backscattering of light.

An optical method is proposed for monitoring the angular distribution of fibers in fiber-containing materials (FCMs) such as paper, nonwoven materials, collagen casing, semifinished textile products, etc. The method is based on the illumination of the FCM of interest by plane-polarized light with a light beam whose plane of polarization is rotating with frequency ω with respect to the axis. The angular backscattering pattern is subsequently analyzed by means of a linear photodetector that is mounted at a constant angle relative to the optical axis and records the amplitude of the ac signal at frequency 2ω. Using samples of various FCMs, it is shown that the method is promising for on-line monitoring of the anisotropy of the angular distribution of fibers in FCMs, regardless of the nature of the fiber material.