Research On Dynamic Characteristics Of Circumferential Micro-grooved Idle Roller In Roll-to-roll Manufacturing System

In recent years,flexible electronics have attracted wide attention.Roll-to-roll manufacturing technology can realize the manufacture of flexible electronics and other new thin film products on a large scale with high efficiency and low cost.In the roll-to-roll manufacturing process,the web is supported,guided and transmitted by a large number of idle rollers.The dynamic characteristics of the idle roller play an important role in the stable transmission of the web.In this dissertation,the circumferential micro-grooved idle roller and the moving web at the idle roller are seen as the research object.The flow field characteristics of the air entrainment between the web and idle roller are researched.With air entrainment,the traction characteristics and follow-up property of the micro-grooved idle roller are researched,which provide a theoretical basis for improving the quality and efficiency of the manufacture of flexible electronic and other high precision thin film products.The main research contents of this dissertation are as follows:(1)The flow field characteristics of air entrainment between the web and the circumferential micro-grooved idle roller are researched.The web deflection equation is established by analyzing the force and moment of the web element at the idle roller based the elastic thin shell bending theory.The Reynolds equation of air entrainment between web and idle roller is established based on the Navier-Stokes Equations(N-S equations)and the mass conservation equation.The air film thickness equation of air entrainment is given.On the basis of theoretical modeling,the effects and variations of web transmission velocity,web tension,web width,friction coefficient,the radius of idle roller and micro-grooved parameters(groove width,groove depth,groove number and groove section shape)on air film thickness are analyzed by numerical calculation(2)The traction characteristics of the circumferential micro-grooved idle roller are researched.Considering the air entrainment,the traction force model of the circumferential micro-grooved idle roller is established based on the mechanical analysis of the web element The traction model in this dissertation is verified by comparing with other scholars.The effects and variations of web transmission velocity,web tension,the radius of idle roller and micro-grooved parameters on the traction characteristics of circumferential micro-grooved idle roller are analyzed(3)The follow-up property of the circumferential micro-grooved idle roller is researched Based on the mechanics theory,the follow-up time model of the circumferential micro-grooved idle roller is established by analyzing the mechanics of the idle roller considering the effect of air entrainment.The effects and variations of the wrap angle between the web and the idle roller,friction coefficient,equivalent roughness,web tension,web width,web velocity,the radius of idle roller and micro-grooved parameters on the follow-up property of circumferential micro-grooved idle roller are analyzed.The critical slip velocity model is established and the effects of web tension,web width and micro-grooved parameters on the critical slip velocity are analyzed.