基于微三角区的纳米纤维定向集聚连续成纱机理及批量制备

At present, most of the electrospinning fibers are collected by the non-woven fabrics in the form of disordered wire mesh, because the continuous and stable high orientation yarns forming difficulties, resulting in nanofibers in the fabric of woven fabrics,knitted fabrics and other aspects of application is severely limited.The existing nanofiber yarn twist triangle zone is too large, resulting in frequent yarn breakage and difficult to batch preparation. In this study,a multi-jets non-blocking umbrella nozzle is used to replace the traditional needles,the nanofibers are prepared for the width of the nozzle.The magnetic field-assisted large dust cage with a spiral groove is used as the batch-oriented fiber collection device,and the large dust cage is equipped with negative pressure flow field,so that the fiber orientation aggregated to the micro triangular zone, with the double dust cage friction spinning twist to achieve low draft, weak tension continuous yarns.This study will built the following two models,including the two - phase flow model formed by nanofibers oriented fibers / electromagnetic under electro - magnetic coupling field and the two - phase flow model and numerical calculation of the concentrated fiber bundle / fluid under the negative pressure flow field in the large dust cage.At the same time, a complete mechanical analysis of the nanofiber yarns in the micro triangule zone under the negative pressure flow field of double-cage friction spinning system will also be built.Moreover,a two-dimensional quasi-static model will be establish to determine the twisted point and the perfect three-dimensional nonlinear oscillation equation will also be establish to control the stability of yarn in micro triangle zone.ANSYS will be use to simulate the oriented fibers in the electromagnetic field and the twisted yarn in the negative pressure flow field to verify the theoretical accuracy.Design advanced elecrospun nanofibers machines to product continuous nanofiber yarns in batches with independent property.

目前大多数静电纺纤维采用非织造布的无序纤网方式收集，原因是连续稳定的高取向纱线成型困难，造成纳米纤维在机织物针织物等方面应用严重受限。现有纳米纤维成纱加捻三角区过大，造成纱线频繁断头难以批量制备。本研究将采用多射流无阻塞伞状喷头替代传统针头，针对该喷头宽幅制备纳米纤维，拟采用磁场辅助螺旋凹槽式大尘笼作为批量取向纤维收集装置，尘笼内配备负压流场，使纤维定向分条聚集至微三角区，配合双尘笼摩擦纺加捻实现低牵伸、弱张力连续成纱。本项目将构建取向纳米纤维/电-磁耦合场两相流模型和大尘笼负压流场定向集聚纤维束/流体两相流模型并数值计算。对微三角区双尘笼摩擦纺负压流场连续成纱进行完整力学分析，建立二维准静力学模型确定微三角区加捻点位置，完善纱线三维非线性振动方程控制微三角区成纱稳定性。采用ANSYS对电磁场取向纤维、负压场定向集聚及加捻纱线进行模拟验证。形成有自主产权的连续纳米纤维纱线批量制备能力。

静电纺纳米纤维通常以非织造纤网形态收集，仅适用于过滤材料、膜材料等领域。将静电纺纳米纤维制备成束状纱线，进而制成机织、针织等纺织品可大幅度拓展应用。针对纳米纤维成纱难题，本项目设计开发了系列多射流伞状静电纺丝喷头，并采用磁场辅助螺旋凹槽式大尘笼作为批量取向纤维收集装置，尘笼内配备负压流场，使纤维定向分条聚集至微三角区，配合双尘笼摩擦纺加捻，由此形成微三角区保证纤维在加捻过程中完全受控，实现了低牵伸、弱张力连续成纱。构建了取向纳米纤维/电-磁耦合场两相流模型和大尘笼负压流场定向集聚纤维束/流体两相流模型，阐明了电磁场变化率、磁场强度变化对纤维取向的影响，为预测和控制纤维取向成型提供了依据。对微三角区双尘笼摩擦纺负压流场连续成纱进行完整力学分析，建立了二维准静力学模型，确定了微三角区加捻点位置，并结合模拟结果，修正上述电磁场、加捻区流场模型。最终建立了具有自主产权的吸湿排汗等功能纳米纤维纱线批量化制备生产线。