An Optimizing Modeling Research Of The Molten Tin In Ultra-Thin Glass Process

Ultra-thin float glass mainly used as FPD glass substrate and the glass cover of instruments is becoming the new economic growth point in glass industry. Surface waviness is one of major factors affecting the quality of ultra-thin glass products. If waviness is not up to standard, the glass covered TCO conductive film will make transparent electrodes contact undesirably and lower the quality of image or touch due to ups and downs on the surface.Waviness may also make the display appear phenomenon of rainbow and make products to be scrapped. The flow and temperature of molten tin are important for the quality of surface because glass is floating on the molten tin in the forming process. The space of tin bath is closed and high temperature, producer can’t predict the flow of tin under production by traditional methods in advance. In this paper, we simulate the flow form of tin under producing 1.3mm glass, with and without adjustment measures by Fluent and improve the forming quality of ultra-thin float glass.Through the analysis of velocity field and temperature field of tin under producing 1.3mm glass, we verify the feasibility of using Fluent to simulate the flow form of tin in forming process of ultra-thin float glass by comparing with production records.Normal flow of tin in the tin bath is forward flow by the glass and backflow at the edge and bottom of tin bath, but backflow at the bottom is not throughout the length of tin bath. The backflow flow into the middle part from edge of tin bath in the slow cooling district and form a spiral vortex in the forming zone.The backflow with lower temperature can persist in the deeper of transitional zone and the upper tin with higher temperature take part in backflow in the stepped tin bath. At the same time, it can reduce the amount of back flow and vortex in the forming area. Barriers can reduce the flux of forward flow at the middle part and back flow at the edge of forming zone. Part of return tin could across the barrier and flow forward. The temperature is more uniform in forming area and the temperature of cooling area is lower in the stepped tin bath with barriers. It’s advantageous to form and cool for glass.Forming area is divided into several regions by baffles and make the side and central tin get full exchange. Most of backflow turn forward flow in transition section and a small part of it can bypass the baffles and flow to the front end of tin bath. Transverse temperature of tin covered by glass strip become uniform and the temperature difference significantly reduce at the forming area. It is advantageous to reduce the difference of thickness and improve the forming quality...