Comparative study of ring yarn properties spun with static and rotary grooved contact surfaces

Abstract

Spinning with a static contact surface is an energy-saving method to reduce spun yarn hairiness; however, the spun yarn irregularity and tensile properties are deteriorated. To prohibit the deteriorations, this paper introduces a rotary grooved surface contacting ring spinning strand within the yarn formation zone. In theory, the modeling analysis of spinning with contact surface is conducted to reveal the prohibition mechanism of yarn irregularity and tensile property deteriorations for a rotary grooved surface. Theoretical analysis results indicated that groove-yarn surface friction could wrap the concentrated hairs onto yarn stem while block inflowing twists to the spinning strangle zone; the rotary grooved surface could reduce twist blockage and hair wrapping concentrations to better the situation after a comparison with the static grooved surface. Then, two kinds of specially-designed grooved cylinders (one was rotatable while the other was static) were used to validate the theoretical analysis. The experimental results showed that, unlike the static grooved cylinder which significantly deteriorated the original yarn unevenness CVm, the rotary achieved significant hairiness reduction without any significant deterioration of other yarn properties. This might be due to the decreased friction and twist propagation for the rotary grooved cylinder contacting the spinning strand. In this case, spinning with a rotary grooved cylinder was preferably applied in the first step to control ring spun yarn hairiness.

Investigation on the processability, structure and properties of micro-/nano-fiber composite yarns produced by trans-scale spinning

“…In the spinning triangle, peripheral fibers with inadequate tension under limited twisting are difficult to be fully embedded into the yarn and the part of single fibers are inclined to be free on surface of yarn body, forming into yarn hairiness (Figure 2). Thus, yarn hairiness is closely correlated with fiber movement and migration in spinning triangle and the characteristics of microfibers [38,39]. Yarn unevenness reflects the uniformity of yarn along its axis.…”

Controlling the Fiber Stress Distribution with Variable-Frequency Step Roll for Tunable Spun Yarn Structures

“…Novel spinning methods [9][10][11][12], such as compact spinning, Nu-torque spinning and groove spinning, have been developed to regulate the fiber stress distribution during yarn formation, thereby adjusting yarn structure as well as improving yarn quality. In compact spinning, a fiber control device is installed in front of the yarn-forming triangle area, which applies a balanced stress on the fiber strands to reduce their width, controlled by airflow, resulting in a ring-spun yarn with tight, clean surface structure and high breaking strength [13,14].…”

Enhancing the Spun Yarn Properties by Controlling Fiber Stress Distribution in the Spinning Triangle with Rotary Heterogeneous Contact Surfaces

“…To overcame the shortcomings of the spinning methods described above, various contact surface apparatuses [ 20 ] were designed to control the fiber motion and spinning tension distribution with the application of multidimensional frictional forces in the yarn formation area, which is considered an easily operated technology with low energy consumption. For instance, an energy-saving apparatus with a static contact surface [ 21 ] was installed in front of the front nip to trap and re-wrap the protruded hairs onto the yarn surface by the force of friction, effectively reducing harmful hairs. However, the irregularity and deterioration of the yarn constituted a drawback of these surface-contacting approaches, resulting from the emergence of fibers accumulation caused by irregular fiber wrapping due to excessive friction.…”