Tension Reduction In Automatic Silk Reeling Process And Its Effect On The Raw Silk

Production of high-grade raw silk is the foundation for increasing raw silk export andproducing high-end silk products. Due to the extensively applied automatic reelingmachine featured with high reeling rate and high reeling tension, the breaking elongationrate of the raw silk is difficult to meet the requirements of the high-end raw silk.Smoothness of the raw silk is difficult to meet the requirements of high-end raw silk. Forsuch a purpose, this paper aims at research on reducing the reeling tension by improvingthe crossed winding process. Based on our newly developed theory and instrument, weexpect to decrease the reeling tension without changing the reeling rate and increase thebreaking elongation to enhance the grade of raw silk as well.In the automatic cross winding process, the cross winding ceramic stand drives the rawsilk to vibrate transversely and form the coiled thread of silks. The governing force of thesliding friction exists between the wet raw silk and the cross winding ceramic stand.Tension difference of the raw silk before and after the cross winding ceramic stand is over3cN, which indicate that the reduction of reeling tension still has the large space to beimproved. In accordance with the basic principle of the rope and the static pulley, wehypothesize that the cross winding ceramic stand were changed into cross winding tubwheel, which might significantly reduce the tension of the raw silk passing through the tubwheel. By analyzing the analytic friction relation between the raw silk and the tub wheel,we concludes the certain rules to principle to be complied with, which means theselection of light weight materials, shape design, smaller diameter, and lubrication shouldbe adopted in the process of machining to reduce the friction coefficient between themandrel and mandrel support piece. Complied with the fabrication principle of the tub wheel, stainless steel mandrel andABS resin are used to fabricate a real tub wheel. During the experiments, the Schmidtdigital tension meter (DTMX-200made in Germany) is used to measure the quantitativetension values for raw silk tension by using the cross winding ceramic stand and crosswinding tub wheel. The results indicate that, the increases of the tension value are0.73cNand0.78cN respectively at the still and transverse movement period, while the increasedtension of the raw silk increasing value by using the cross winding ceramic stand is3.08cNand5.49cN. The above results demonstrate t effectiveness of the cross winding tub wheelfor lowering the raw silk tension.The cross winding tub wheel is installed on the reeling machine. The electronicmachine with model YG020A is used to measure the breaking strength and elongation rateof the raw silks reeled by the cross winding ceramic stand and cross winding tub wheelrespectively. The results show that the breaking strength is almost same, while the breakingelongation of the raw silk reeled by the cross winding ceramic stand is21.336%and that ofthe raw silk reeled by cross winding tub wheel is18.441%. The latter elongation rate isdecreased by2.895%, which is inconsistent with our purpose of the design of the crosswinding tub wheel. The reason of such problem is due to the defective design of the tubwheel, which causes the silk jumping or tub wheel sticking in the real reeling process.Therefore, a new design of V-shaped tub wheel is proposed in the end of this thesis.Apart from above works, a system consisting of the raw silk transmitter, photoelectricsensor, data acquisition card and software based on LabVIEW is designed to study theroundness of raw silks reeled by the cross winding ceramic stand and cross winding tubwheel. The measuring results show that average roundness of raw silk wound by crosswinding ceramic stand is0.7401and average roundness of raw silk wound by crosswinding tub wheel is0.7706. It indicates the roundness of the raw silk is improved after theusage of the cross winding tub wheel.Three main innovations in this paper are listed as follows. (1) we proposed that the cross winding ceramic stand were changed into crosswinding tub wheel in the automatic reeling process, which significantly reduce the tensionof the raw silk passing through the tub wheel and improve the silk roundness.(2) A kind of tub wheel and its attachments were invented and were used in automaticreeling process. The experimental results show that the intended purpose was achieved.(3) A system was developed to evaluate the silk roundness, which also can be used toevaluate the silk evenness. It has an important value to the evaluation of the silk qualityindicators.