Research On Key Technologies Of Chitosan Continuous Filament Preparation

Chitosan fiber has good hygroscopic behavior, air permeability, antibacterial property, adsorption property, biocompatibility and biodegradability, and it is a kind of biomass material without poisonousness, harm and secondary pollution and it is used in medical textiles, health care clothing, food industry, chemical industry and other fields widely.Currently, the preparation of chitosan staple fiber and tow has been very mature, but there were many problems in the preparation of chitosan continuous filament, and these increased difficulty for achieving industrialization. There are two reasons, on one hand, the solid content of chitosan spinning solution is low, splitting washing and drying method not only effect the performance of fiber, but also limit continuous production and application of chitosan fiber greatly. On the other hand, although the continuous winding have been achieved in the process of the preparation of chitosan filament at present, after wound to a certain length, it needs to be cut off for washing and drying, and it is difficult to realize continuous spinning. Therefore, how to realize continuous winding and dewatering of chitosan fiber have become a key technical problem as for chitosan filament. The subject combined theory with practice to prepare chitosan continuous filament.Firstly, the paper studied the critical processes of solidification, stretching, washing, dehydration of chitosan wet-spinning, and analyzed the affect of process parameters including coagulation bath components, coagulation time, draw ratio, washing time, types of dehydrating agent on crystalline and orientation, mechanical properties and appearance shape of chitosan fiber, and optimized the process parameters.Secondly, the subject designed high efficiency circulating dehydration system according to the key technology including winding and dewatering for the preparation of chitosan filament, and this system can realize the recycle of absolute alcohol. The three-dimensional model of winding and dewatering device were designed using CATIA software, and these were manufactured successfully, and then the paper used GAMBIT and FLUENT of fluid dynamics software to simulate dehydration process of chitosan filament, and the distribution of flow field was obtained including velocity, pressure and turbulent kinetic energy, and analyzed the simulation results. This approach reduced test cost and improved the traditional dehydration methods, and provided practical guidance significance for preparing chitosan continuous filament.Finally, the paper determined the process parameters of chitosan filament combining simulation results, and analyzed its morphology and performance in order to guide production and application of chitosan continuous filament. In addition, the paper put forward future research direction and prospect.The results of this study showed that the experiment could obtain chitosan filament with excellent performance in the light of optimized spinning process parameters and dehydration process with cartridge winder and dewatering tank. The results had a guiding significance in regard to the preparation of chitosan continuous filament.