Study On Spinning Technology And Yarn Structure Of Ramie Compact Yarn

The compact spinning technology based on the ring spinning technology is widely used for its excellent yarn quality. However, the researching work on the spinning mechanism of compact spinning technology and its yarn structure is very little for its short developing history, we mainly focused on the area of cotton manufacturing. This paper will systematically study the compact spinning technology of ramie manufacturing, and then with the actual results on hand, analysing and exploring the relations between yarn structure of ramie compact spinning and the relevant technological parameters, analysing the relations of yarn structure and properties. Based on which this research pay more attention to the practicability of ramie compact spinning technology, and will supplied as the data reference for the scale production of compact spinning technology in ramie field.The experimental studies carried out in this article are as follows:1. By comparing and analysing the compact spinning technologies at home and abroad, this thesis adopts the method of air current compact spinning and does the tests on the wool spinning frame TB01B, and the compact spinning devices are installed on it.2. The raw material is the combing ramie roving, linear density of roving is 4.39g/10m. The trial test are as followings, spinning the 36Nm ramie yarn by utilizing the compact spinning technology, exploring the technologies parameters which influenced the yarn properties, then choose the spindle speed, the underpressure, drafting times in back-zone field and twist factors as the key factors of this article, and then exploring the relations between technology parameters and yarn performance, the number of hairiness in the range of 3-9mm, Uster evenness CV values, thin and thick nodes, twists and other index of quality are selected as the index points for evaluating the quality of ramie yarn.3. In order to seek for the influence of the four key factors to ramie compact spinning, that is the underpressure in gathering area, the spindle speed, twist factors and drafting times in back-zone field. Single factorial design experimental is carried out in this experimental conditions. By using quadratic general rotation design method to design the experiments and establishing multi-objective mathematical pattern, and then optimize the technological parameters, and then do the verification experimental.4. We select Uster evenness, breaking tenacity, twists, fineness of yarn and so on as the criteria of evaluation of yarn structure and yarn quality, and then compare the differences of compact spinning ramie yam and ring spinning ramie yarn.Theoretical analysis and experimental study show that:1.It is practicable to do the experimental on the wool spinning frame TB01B, and the compact spinning devices are installed on it. By doing the single factorial experiments on the underpressure, spindle speed, drafting times in back-zone field and twist factors, the ranges of these four single-factors are preliminary determined respectively. Conclusion can be drawn from spinning experiments and ramie compact yarn with better quality can be obtained with the following conditions, the spindle speed is between 6000r/min-7000r/min, the twist factors is between 95-100, drafting times in back-zone is near 1.1, underpressure is between 250H2O-350mmH2O.2.By using quadratic general rotation design method to design the experiments and establishing multi-objective mathematical pattern, and then optimize the technological parameters, and then do the verification experimental. The optimal parameters for spinning 36Nm ramie compact yarn are:the twist factor,97.4; the drafting times in back-zone field,1.08; the spindle speed,6233.3.By doing the verification experiment with the optimized parameters and comparing the results, we could ge the conclusion that the optimum values of drafting times in back-zone field, twist factors and the spindle speed should be smaller setting. By comparing the yarn quality and yarn structure of the same number of compact spinning ramie yarn and ring spinning ramie yarn, we find that the fiber arrangement of the compact yarn are more tight than the ring spinning yarn, the appearance are more bright and clean, less hairiness, and higher fiber density. Also,the diameter of the compact yarn are smaller than the ring spinning yarn, and the breaking tenacity are higher too.