Hairiness measurement of textile yarns using crossed polarizers

Some of the fibers making a textile yarn are not contained in the yarn body and these fibers represent the hairiness of the yarn surface. Hairiness measurement of textile yarns is very important from the point of view of the textile industry. It is necessary to have sensitive, accurate, and fast methods to measure hairiness. In this article, a method developed to measure hairiness of textile yarns is discussed. When a yarn is illuminated by a plane polarized light beam, a portion of the incident beam is scattered from the yarn body and the protruding fibers. The light beam after the yarn will contain polarized and depolarized components. An analyzer with its plane of polarization perpendicular to that of incident light will allow only the depolarized portion, which contains the information about the hairiness, to pass through. By calibrating the technique using textile yarns having known hairiness, the setup can be used to determine hairiness very accurately.