Abstract:

Objective In order to improve the quality of yarn and textiles, this study tests and characterizes the fiber hook in chemical fier slivers, which is one of the most important internal performance indicators of fiber slivers, in order to explore the benefits to yarn producers in setting up production processes and optimizing spinning production parameters.

Method In this study, the cellulose fiber and polyester fiber were selected to be the research objects, and the tracer fiber method was used to evaluate the fiber hooks in the corresponding raw fiber slivers, head slivers, and end slivers. Firstly, the fluorescent fiber was made and mixed with the raw material for making the raw slivers. The specific forms of the hook fibers were defined, the state of various fibers in the sliver was observed, and the proportion of the hook fiber in each state was obtained according to the hook fiber definition.

Results In this study, the real state of fluorescent fibers in the viscose and polyester raw slivers, head draws and end draws was observed and analyzed, and various forms of fluorescent fibers were defined and classified. The fibers in the yarn sliver were divided into straightened fibers, broken fibers, zigzag fibers, 0-degree back/front hooking fibers, acute angle back/front hooking fibers, obtuse angle back/front hooking fibres, 2-end folding fibers, and 2-end acute angle hooking fibers. According to these 18 types of observed fluorescent fiber states, and the proportion of various forms of fibers was obtained, the results showed that the proportion of posterior hooking fibers in the green sliver was the largest, and more than 50% of the fibers were shown as posterior hooking fibers, and the proportion of front hooking fibers was about 10%, which was much lower than that of the back hooking. This was due to the configuration of the comb needle between cylinder and doffer and the relationship between specifications and carding, and therefore the probability of various fibers on the cylinder to be transformed to the upper back hook of the doffer was greater than that of the front hook, causing the directional problem of more back hooks in the green sliver. Due to the drafting effect, the straightened fibers in the head drawing were significantly increased, and when the back hooking fibers in the green sliver was transfered onto the cylinder and then led out to feed the head, they became the front hooking fiber. In this process, part of the hooked fibers were drawn and straightened, resulting in the reduction of the front hooking fibers in the head drawing compared with the amount of back hooking fibers in the green sliver. The hooked fibers in the end draw was straightened again, and the front hooking fibers in the head draw was encircled into the sliver and then led out to feed the second draw, hence forming the back hooking fibers.

Conclusion The tracer fiber method can not only accurately reflect the various stages of the fibers in the sliver, but also accurately calculate the proportion of fibers in various stages in the sliver produced by this process through the observation of a certain number of slivers. By making fluorescent fibers, the state and number of fibers in the sliver can be accurately recognized and measured by using tools such as fluorescent light boxes. This study reveals that the ratio of fluorescent fibers to raw materials was 1/1000 under the condition that the observation results were not affected, and a mixing method of "small batches and multiple batches" was established to allow the fluorescent fibers and raw materials to be mixed evenly. At the same time, the morphological characteristics of various hooking fibers in the yarn sliver are defined in detail, and the observed data results also provide a more detailed and comprehensive original data accumulation for the follow-up research on the final yarn quality and the relationship between the hook.

Key words: yarn quality, viscose fiber, polyester, fiber cook, tracer fiber method, fiber morphology in combing