Numerical Simulation Of The Annealing Process Of TFT-LCD Substrate Glass Produced By Float Process

With the development of digital display industry,the production of large screen,high resolution display panel is the main trend.Using traditional floatation process to produce advanced generation TFT-LCD substrate glass for display is the main approach to reduce production cost and improve product quality.In order to produce substrate glass with high imaging quality and good mechanical properties,precise annealing control is needed.In this study,FLUENT software was used to simulate the thermal environment in zone A and zone B of the glass annealing furnace with the thickness of 0.4mm,0.5mm and 0.7mm.The temperature distribution of glass plate surface,cross section's temperature distribution and flow characteristics of different position of kiln are obtained.Under the condition of maintaining the same electrical heating power and the matching ways of zone A,the temperature changes of different thick glass plates and annealing furnace' space thermal environment with three heating modes(electric heating closing,side heating and uniform heating)in zone B were simulated.The results show that when the electric heating in zone B is turned on,the temperature of glass in the annealing process can be guaranteed to be in the viscoelastic temperature range.When using the side heating type,as the thickness of the glass plate increases,the surface temperature at the exit of zone B gradually decreases.In the case of uniform heating,the 0.5mm glass plate has the highest surface temperature at the exit of zone B,and the cooling process in zone B presents a linear trend.When the space heat transfer process of annealing furnace was completed,using postprocessing software to extract the glass surface temperature and write it as a temperature load with APDL.Using Workbench transient thermal and transient structure module,analysis the surface temperature field,end face temperature field and surface stress of different thick(0.4mm,0.5mm and 0.7mm)glass strip model under three heating modes.The results show that when the electric heating in zone B is turned on,the temperature difference between the end face core layer and the surface layer of the glass plate decreases as the thickness increases.When the electric heating is closed,the temperature difference between the end face core layer and the surface layer increases as the thickness increases.The maximum tensile stress and maximum compressive stress decrease with the increase of the thickness.Research on the relationship between thermal environment control of annealing furnace and glass plate stress based on the simulation results.