How to to avoid the kevlar rope mark on the tempered glass

For glass tempering furnace, you know, for the cooling section, the transmission roller is steel roller covered by kevlar rope. 

During tempered glass processing, But after tempering, some time, you can find there is some kevlar rope mark on the glass surface

If you meet this problem, we suggest you to check below reason:

1. The glass is over heated inside the heating furnace, or the heating temperature is over high, or heating time is over long.

2. The oscillation speed of the cooling section is slow,

 3.The kevlar rope is broken, worn, or has dust on it.