Controlling residual stress in float glass may start in the annealing lehr, however, monitoring the profile of the temporary and permanent stresses in the ribbon before it reaches the cutter is just as important. Many float glass plants use manually operated visual devices, such as a polariscope equipped with a Babinet compensator, to measure stress at several points across the glass at the cold end. Generally, these methods lack consistency, precision and speed, all of which are essential to "closing the loop" by making timely upstream process control adjustments. The new SCA-1500T from Strainoptics can be used on virtually any float glass thickness and features a specially designed, high-intensity light source that enables accurate stress profiling on very dark glass, without rotating components or expensive laser optics.
