Tempered chipping

Dear All,

May I ask your assistance with regards to our tempered glass? We found out that our tempered glass was chipped off (shell type chippings) on the edge. Instead of having a spontaneous breakage, the glass stood still.

We want to know the reason why it does not break and your recommendations if there is a need to improve on this process. Hoping for your reply. Thank you.

Guest User
Sun, 01/12/2013 - 11:25

Hi, Without a close inspection of your glass I can only surmise what the problem might be but suspect that the glass edge is being fractured during the pre-process work, or (less likely) possibly during the heating. I would look closely at the following:
1. Glass quality – check the stress levels present in the raw glass received at the factory (incorrectly annealed glass will not cut or breakout cleanly, leaving fractures in the glass edge which may not be removed by the edge working process).
2. Glass cutting – wheel pressure, wheel angle versus glass thickness, and wheel condition.
3. Edge working – ensure not too fast or too much pressure (overheating the edge of the glass) and check for correct grit size (120 grit is a good general purpose size).
4. Good ride inside the furnace during heating – severe warping can cause chipping/fracturing of the edges of the glass which will fly off during the quenching.
Hope this helps.
Jonathan Barr

Guest User
Tue, 18/02/2014 - 01:30

Your furnace is radiation or convection? Radiation furnace heating not equal in the whole furnace. Convection furnace would be much better.

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