Study On A New-type Spinning Technique That Is To Reduce The Hairiness Of Flax/cotton Blended Yarn

In traditional flax/cotton blended spinning, a large amount of hairiness is produced on the surface of yarn because of the high initial modulus, big rigidity and poor inner-fiber cohesion force of flax fiber. In general, the enterprises solve the problem by using negative compact spinning technique or RoCoS compact spinning technique, however, there exist some problems utilizing them. As for the former, the factories have to pay a large sum of money for purchasing the equipment, consuming plenty of energy and maintaining the machines; the cost of RoCoS compact spinning devices is also expensive. As the limit of compacting aisle, the effect of reducing hairiness of RoCoS compact spinning is not as good as that of negative compact spinning. What's more, it deteriorates the yarn evenness. To solve all the problems mentioned above, a new-type spinning technique which concentrates on reducing the hairiness of flax/cotton blended yarn is proposed in this dissertation, it has some advantages, such as low cost, no energy consumption and easy operation.Based on the theory and practice of compacting spinning, a new-style spinning technique, aiming to reduce the hairiness of flax/cotton blended yarn, was summarized in this project. The theory of it is that the fiber strand is leveled by gathering in main drafting zone in advance; a new twisting triangle zone is built in front of front roller nip and gathered by the specialized devices, which is the main part of gathering process. The experimental equipment is designed based on the new theory, including rotatable gathering devices(grooved cylinder), fixing holders, support shafts and positioned columns. After assembling, the designed devices were applied to experiment and the data indicates that the brand new spinning technique can decrease 15% of the hairiness than original yarn, and no changes happen to yarn tension. From the experiment, it was found that the parameters of gathering groove(V-groove) had significant influence on experiment result, so the width and depth of V-groove, the diameter of arc in the bottom of groove and positioned column were studied, the results tell that the devices could cut down 25% of hairiness when the width range and depth of V-groove a;re 2.0-2.5mm and 0.8mm, the diameter of arc in the bottom of groove and positioned column are 0.3mm and 7mm respectively. To improve the experiment effect, the parameters and form of gathering groove were adjusted, by analyzing the data, it is clear that the V-groove can reduce 35% of yarn hairiness at most, the width and depth of groove and the diameter of arc are 2.0mm, 1.8mm and 0.4mm separately, while the tension and evenness of yarn does not change compared with original yarn. Y-groove was used to eliminate the influence of spinning guider movement on reducing hairiness, it ensures similar proportions of decreasing yarn hairiness during the whole spinning process, in the same time, the evenness and tension of yarn are still almost equal to those of original yarn. An important conclusion is drawn from the further study on the compacting theory, increasing the compacting distance and time and improving the compacting stability can reduce more hairiness. According to that, an extra grooved cylinder was integrated to the gathering apparatuses, and it is known that the creative double Y-groove cylinders can decrease as much as 50% of yarn hairiness, meanwhile, it can be summarized that the innovative spinning method has no effect on yarn tension and evenness. At last, this kind of spinning method was compared with negative compact spinning, the results demonstrate that the breakage ratio and diagram per one hundred meters of the yarn spun by the former are better than those of negative compact spun yarn, while the yarn hairiness and tension are worse than those of the latter.