According to LandGlass, when processing curved glass in a glass tempering furnace, cracks on the curved edge of the tempered glass can have a few causes
- When the glass is tempered in the bending chiller, if the process parameter of the quenching wind pressure is set too high, it will cause cracks on the curved edge of the tempered glass. In this case, we should reduce the wind pressure parameter settings according to the actual situation.
- The cracks on the curved edge of the bent glass may also occur if the edges are not sufficiently heated in the heating chamber and the temperature of the edges are too low when exiting the furnace. To solve the issue, we should increase the set temperature for the glass edge so that the edges can be fully and effectively heated.
- If the bending speed of the lower chiller is too fast, it will also cause cracks on the curved edge of the tempered glass. In this case, we should change the arcing speed parameter of the bending chiller in the tempering process parameter page of the control software to appropriately reduce the arcing speed of the bending chiller.
- In the quenching process, if the waiting time before blowing in the process parameters is set too long, it will cause cracks on the curved edge of the glass. An effective solution is to change the process control parameters and appropriately shorten the waiting time before blowing.
- If the pre-treatment of the glass edge is not done properly in the cold processing stage, it will lead to cracks on the curved edge of the glass during tempering. Therefore, we should not allow glass that does not meet the process requirements to enter the furnace.
- If the valve of the wind pipe is not closed tightly, the resulting air leakage will cause low air pressure of the bending chiller, which in turn will cause cracks on the curved glass edges. In this case, we should check for air leakage and seal it properly.