Experimental study of capillary flow in yarns

Capillary flow is studied in polyester and polyamide yarns and glass fibers using a technique based on the analysis of CCD images taken during the cap illary rise of colored liquid in yarns. The transition from dry yam to wet yam is not abrupt. Experiments analyze the causes of this gradually rising liquid front and the results an explained. As expected, the kinetics of cap illary rise always follows the Lucas-Washburn equation, but the great dispe rsion of the experimental results along the yarns is attributed to the yam heterogeneity of the interfilament space.