Numerical Simulation And Experimental Verification On The Disc Type Electrostatic Spinning

Electrostatic spinning is a new type of spinning built on the electric field force.In concrete terms,By applying high voltage to the polymer solution,it produces a large electric field between the spinneret and the receiver.When the electric field forc e is large enough,the polymer solution conquers the surface tension,and then it causes wave and forms jet flow.In the process of injection,the polymer solution is evaporated and solidif ied,eventually forming nanofiber.Because of the low efficiency of the traditional single needle spinning method,it's difficult to realize industrialization of mass production.Therefore,this article puts forward a disc slit type electrostatic spinning method.Because the polymer solution at edge of each layer of the spinneret with the maximum curvature has the highest electric intensity,it can produce multiple jets at the same time,this will greatly improve production efficiency.The polymer solution adopted by electrostatic spinning is a kind of incompressible visc ous fluid,and the jet's movement is the complex.In order to analysis the formation and movement of the electrostatic spinning jet,it involves much relative knowledge of fluid mechanics and electromagnetism.Through setting up the electrostatic spinning mechanical model,the Navier-Stokes equation is used to analysis the mechanism of electrostatic spinning.the relationship between the jet radius and the distance from the spinneret to jet is carried out,at the same time the relationship between the jet velocity and the tensile force is carried out.Also,after mechanics analyzing on the stable and unstable per iod of the jet,the relationship between the jet radius and the related distance is carried out.This article presents a disc slit type electrostatic spinning spinneret's design.The electric field distribution of the spinneret is the crux of the formation and trajectory of jets.The computational software Ansoft Maxwell 12 is adopted to simulate the electric field distribution of the spinneret,then the influence of electric field intensity to the jets can be analysed simply.After calculation and s imulation of electric field,results show that the whole round cambered surface of the spinning solution at edge of each layer of the spinneret with the maximum curvature has the highest electric intensity.And through the simulation of the electric field distribution of different spinneret parameters such as layer,the height of the spinneret.After comparative analysis,the influences of various parameters on the electrostatic spinning fiber are obtained.Because the electrostatic spinning jet's movement is complex,the experiment is difficult.The computational software Fluent2.3.26 is adopted to simulate the electrostatic spinning jet's movement,then the influence of the drafting force to the formation of the fibers can be analysed simply and intuitively.The physical model of the free surface electrostatic spinning on the disc slit type spinneret was established.After calculation and simulation of the jets,results show that with the decrease of the drafting force,the jets is eas ier to bend and stretch more fully,so the formed fiber is also better.In order to verify the conclusions of theoretical analys is and numerical s imulation,the real electrostatic spinning experiments are taken finally.Putting PAN water solution on the disc slit type electrostatic spinning spinneret,and then the experiment can be done on the electrostatic spinning machine.By changing the parameters such as solution concentration and voltage size,comparative analysis can be done in the process of the jet's formation.Also,microscopic observation of the nanofibers can be taken to analyze the f iber number,formability and other parameters.Finally,this article has done some verification among the theoretical analysis,numerical simulation and experimental research conclusions.