Analysis of Blend Irregularities and Fiber Migration Index of Wool/Acrylic Blended Worsted Yarns by Using an Image-analysis Technique

Abstract

Fiber-blending irregularities and fiber distribution in blended-yarn cross-sections are particularly important in determining the mechanical, functional, and aesthetic properties of textile products. In the work reported in this paper, wool/acrylic blended worsted yams with a linear density of 32 tex (31 Nm), twist level of 414 tpm and with different blend ratios (75/25, 50/50 and 25/75) were produced. The digital images of yarn cross-sections with pre-dyed fibers were prepared using an optical microscope and a digital image capturing system. By applying a mathematical technique on bitmap data, the Index of Blend Irregularities, sizes of fiber clusters and preferential fiber migration were measured. The experimental results indicated a good correlation between the proposed image processing technique and that of the visual method. The index of blend irregularities and sizes of fiber clusters for wool/acrylic blended yarns were shown to range from 1.97 to 2.2 and from 3.87 to 4.88, respectively. In addition, the acrylic fibers in blended yarns were preferentially positioned in outer layers of the yarn cross-section.