White haze can appear in the center of tempered glass during the glass tempering process for several reasons:

1. The heating parameters of the tempering furnace are set unreasonably, causing the glass to be heated unevenly in the furnace and warp.

2. The synchronous accuracy of the ceramic roller in the heating furnace does not meet the standard, or its TIR is too large.

3. The self-aligning bearing of the ceramic roller is not properly adjusted.

4. The commutation acceleration and deceleration time of the furnace drive motor is too short, causing the glass to slip.

5. The setting of the oscillation speed of the glass in the furnace is unreasonable, reduce the oscillation speed of the glass in the tempering furnace.

6. The thermal balance setting of the heating furnace is unreasonable; appropriately increase the pressure or opening time of the thermal balance.

7. The convection gear position and timing settings of the heating furnace are unreasonable, causing uneven heating of the glass.

8. The horizontal precision of the ceramic roller conveyor in the tempering furnace is not up to standard.

9. Faults in heating elements or thermocouples, causing uneven heating.