Abstract:

Objective As a combination of segment color yarn and slub yarn, segment colored slub yarn has multi-component changes in shape, structure and color, which gives textile and garment a stronger sense of color hierarchy and mechanism fullness, and provides new impetus for fabric design. At present, the methods of spinning segment colored slub yarn mainly focus on the ring spinning machine, but few reports on the rotor spinning segment colored slub yarn are known. In this paper, how to spin segment colored slub yarn with shape, structure and color timing changes by three-channel CNC rotor spinning is studied.

Method Firstly, the linear density, twist, blending ratio, thick and thin knot and color of segment colored slub yarn were parametrically characterized and the corresponding mathematical model was established. Then, combined with the principle of yarn formation by three-channel CNC rotor spinning and the mechanism of yarn morphology regulation, the formation mechanism of thick and thin knot and segment color of segment colored slub yarn with spinning timing distribution was constructed based on the three-channel CNC rotor spinning machine. On this basis, eight different styles of segment colored slub yarn with timing distribution of thick knots and their fabrics were prepared, and the mechanical properties of the yarns were tested.

Results In this study, eight types of segment-colored slub yarns were designed, comprising four with short slub segments (125.6 mm length) and four with long slub segments (1 420 mm length). Among the four short-segment slub yarns, two types were blended from two colored fibers, while the other two incorporated three colored fibers. Compared to the two-color slub segments, the three-color variants demonstrated richer color expression and enhanced three-dimensional effects on fabric surfaces. Similarly, among the four long-segment slub yarns, two types were blended from three colored fibers, while the remaining two used two colored fibers. Each long-segment slub yarn featured two distinct color combination patterns, exhibiting greater color variability and more pronounced color transitions compared to the former. The mechanical property tests performed with the XL-2 yarn strength tester showed that the yarn strength follows this order from lowest to highest: the base yarn segment is less than the base-slub transition segment is less than the slub segment. All test results met the first-grade requirements of FZ/T 12001―2015 ‘Cotton Rotor Spun Grey Yarn’.

Conclusion Based on the principle of three-channel CNC rotor spinning, this paper extends the yarn forming principle of three-channel CNC rotor spinning machine for spinning segment colored slub yarn, and establishes the formation mechanism and timing model of base yarn, thick and thin knot and color of segment colored slub yarn. The eight kinds of segment colored slub yarn fabrics have the characteristics of bright color, unique pattern, changeable style and strong three-dimensional sense, which provides a new idea for the design of clothing fabrics. However, due to the limitation of the mechanical structure (rotor circumference) of the rotor spinning machine, the shortest length of the slub segment of the spun segment colored slub yarn has to be greater than or equal to the rotor circumference, which is also the core issue to be faced in the future.

Key words: segment colored slub yarn, three channel rotor spinning, spinning process, time series, thick and thin knot, mechanical property