Abstract:

Objective To shorten the raw silk process and improve the existing silk reeling techniques onto bobbins, a novel type of silk reeling machine was developed based on the automatic silk reeling machine. The new type of silk reeling machine was equipped with a single thread-controlled winding device and an active overfeeding device with an electromechanical integrated and compact structure. This research was set to investigate the optimization of the process parameters of the novel silk reeling machine and the properties of the raw silk.
Method The process parameters were optimized using the orthogonal analysis method. We selected the winding speed, overfeeding ratio, drying temperature, and oil concentration as test factors, and the breaking strength, breaking elongation rate, and cohesion property of the raw silk prepared by the new silk reeling machine as test indexes. After the optimization, the differences between the raw silk on bobbins prepared by the new silk reeling technique onto bobbins, the raw silk on small reels prepared by the automatic silk reeling machine, and the traditional raw silk on bobbins prepared by processes such as re-reeling, finishing, foaming, winding were investigated.
Results In the optimization experiment of parameters, the winding speed showed a very significant effect on the breaking strength and breaking elongation rate of the raw silk. The overfeeding ratio and drying temperature have a significant or very significant effect on the breaking strength, breaking elongation rate, and cohesion property of the reeled raw silk. However, the oil concentration has no significant effect on the breaking strength and breaking elongation rate of the raw silk. It only has a very significant effect on the cohesion property of the raw silk. For the selected raw material cocoons, when the winding speed is 130 m/min, the overfeed ratio is 1.15, the drying temperature is 90 ℃, and the oiling concentration is 5%, that is, when they are used as the optimal process parameters, the raw silk on bobbins prepared by the new type of silk reeling machine has relatively good breaking strength, breaking elongation rate and cohesion property at the same time. In the comparative experiment of the three kinds of raw silk, the surface morphology of the raw silk on bobbins prepared by the new silk reeling technique onto bobbins is similar to that of the traditional raw silk on bobbins, better than that of the raw silk on small reels. The molecular composition, crystallinity, and other microstructures of the three kinds of raw silk are similar(Fig. 4, Fig. 5). The breaking elongation rate, softness, and other properties of the raw silk on bobbins prepared by the new silk reeling technique onto bobbins are similar to those of the traditional raw silk on bobbins, while the breaking strength and cohesion property of the raw silk on bobbins prepared by the new silk reeling technique onto bobbins are significantly better than those of the traditional raw silk on bobbins.
Conclusion The research provides a practical basis for the development of silk reeling techniques onto bobbins. The raw silk on bobbins prepared by the new silk reeling technology onto bobbins has similar properties to the traditional raw silk on bobbins, which can meet the subsequent weaving needs of raw silk. Moreover, the new silk reeling technique onto bobbins can reduce the raw silk processing process, such as rewinding, finishing, soaking, and other steps, improving production efficiency, reducing production costs, reducing energy consumption, and protecting the environment. Therefore, the new silk reeling technique onto bobbins has a good application prospect.

Key words: silk reeling technique onto bobbin, silk reeling equipment, raw silk, short process, process optimization, mechanical property