Study Of Melt Flow In The Composite Spinning Components And Numerical Simulation Of Fiber Forming Process

Multi-component fiber and profiled fiber is two kinds of key technologies in differential fibers. Compared to America, Japan and other developed countries, chemical fiber industry in China faces many problems such as large quantity with lower quality and lower differential rate. At present, in our country the new fiber product development mainly is by the imitation of new products abroad. Be lack of theoretic guide of effective spinning process conditions, the fiber forming process is mainly depending on experience and experiment, increased research costs and cycle. So, my research is mainly about study of melt flow in the composite spinning components and numerical simulation of fiber forming process.Firstly, analyse the overview of the multi-component fiber and composite spinning components, then based on Knowledge of polymer rheology, study the melt flow process in the composite spinning components, last establish a mathematical model of melt flow in the spinneret, and derived melt holes in the spinneret when the steady flow velocity and shear rate distribution mathematical model. With the establishment of Gambit on the skin-core type of multi-component physical model of spinneret hole and mesh, using Polyflow simulate the spinning movement of spinning melt in micropores, and its speed, pressure and temperature, by analyzing the affection to melt join at different ratio flow, make a conclusion about the situation in micropore, and make it visual, which will provide the foundation for actual production.Secondly, it detailedly analyzes the forming process of melt extrusion. The Arrhenius model, differential viscoelastic model-PPT model and flow-induced crystallization model are applied to describe the spinning melt extrusion stretch forming, which makes the melt spinning model more accurate and more practical. The establishment of circular fibers 2D numerical model to simulate the distribution of flow parameters such as speed, temperature, crystallinity, etc. It emphasize the there physical phenomenon(Extrudate swell, necking, crystallization) in high-speed spinning process. Compared with the melt spinning results, the simulation results is full compliance. After that, by the establishment of multi-component co-extrusion of the numerical model, it pays more attention to simulation and discussion of the affection to co-extrusion forming process of the skin-core fiber changing the flow field parameters,such as:entry flow ratio, temperature, velocity, and make a useful conclusion.Finally, establish a three-dimensional numerical model of cross fibers, mainly profiled fiber forming process for the deformation of fibers to study the physical phenomena and find the key reasons. Comparing numerical simulations of the cross section shape and fiber spinning experiment results, it proves the exactness of simulation.