Recently, large and thin glass substrates are transported by air film conveyors to reduce surface damage. On the production line, the glass substrates are desired to be transported flatly on the conveyor to ensure the quality inspection. A method by feedbacking film pressure to the theoretical model is proposed for estimation of the deformation of the glass sheet, and the validity of the method is theoretically and experimentally verified. First, a theoretical model including the flow behavior through a porous-walled gap is established, and the film pressure distribution can be predicted by solving the model. Then, an experimental setup that can simultaneously measure the film pressure and the flatness of the glass sheet is established, and, the validity of the model is verified experimentally. Next, with the pressure points at the grooves as the boundary and the pressure points at the flange area as the feedback, an algorithm is applied to shape the one-dimensional deformation at the centerlines in accordance with a quadratic curve. Furthermore, two-dimensional deformation of the glass sheet can then be estimated by an interpolation operation. Comparisons of the calculated results with the experimental data verify the effectiveness of the estimating method.
Fabrication of ultra-thin glass sheet by weight-controlled load-assisted precise thermal stretching