Visualisation and Determination of the Geometrical Parameters of Slub Yarn

This paper presents an analytical method of determining slub yarn geometrical parameters based on a 2D visualisation image of a slub yarn. The method can be used to adjust the slub yarn mechanism by comparing experimental results with the setting used. Geometrical size data of slub yarn are acquired by DAQ (Data Acquisition Card), and expressed as voltage signals. The dynamic threshold method is used to separate the base and slub parts, and the geometrical parameters of each part can be acquired through analysis of the new curve. The slub length can be plotted against the distance between slubs to give a 2D visualisation of any pattern in the periodicity. Characteristic lengths and spacing can be estimated from the plot. According to the experimental results, the slub length is longer and the slub distance shorter than the values set for the mechanism of the spinning frame.