Evaluation of a Digital Image-signal Approach on the Automatic Measurement of Cotton Yarn Snarls

This paper is the second part of a series reporting the recent development of a computerized method for the automatic measurement and recognition of yarn wet snarls from an image of snarled yarn samples captured in a water bath. In our earlier work, a digital image-signal approach for fully computerized yarn-snarl measurement was developed and the effects of various influencing factors on the recognition algorithms were numerically examined. In this paper, the feasibility and accuracy of the fully computerized method on the measurement of actual yarn wet snarls are evaluated through laboratory experiments. One hundred percent cotton ring spun single yarns of 7, 10, 16, and 20 Ne are prepared and used for the evaluation. In addition to the number of snarl turns per unit length, the snarl height and width of the yarn samples are also objectively measured by using the computerized method. The measurement results obtained by the computerized method are analyzed and compared with those measured manually by using a twist tester and an interactive computer method.