Choose a reasonable heating temperature and effectively control the temperature in the furnace. Glass cutter, radiation and convection. The electric furnace load mentioned here does not refer to the area occupied by the glass in the electric furnace, but refers to the relationship between the glass thickness, the heating temperature and the heating time. At present, the heating section of tempered electric furnaces used by most manufacturers can generally be divided into many very small heating zones. Under normal circumstances, in the heating area of the central heating element of the electric furnace, there is always glass that absorbs heat. There is glass, which is regional, and the heating effect is also regional. If the heat consumption of a certain area in the electric furnace exceeds the heating effect, the temperature in this area begins to fall. This is the overload phenomenon. The success of glass tempering is Whether it mainly depends on the place where the temperature of the glass plate is the lowest, once the electric furnace is overloaded, the temperature of the electric furnace will drop, causing the glass to break when it is cooled in the cooling section.
Second, choose a reasonable heating time. The heating power of the tempering furnace is fixed. Generally, the heating time is about 35 to 40 seconds per millimeter of glass, for example: the heating time of 6mm glass is about: glass cutting machine, when the thickness of the glass is 12 to 19mm The basic calculation method of heating time is about 40 ~ 45 seconds per 1mm thickness of glass.
Third, to achieve uniform heating, the placement of the glass on the wafer stage is also very important. The reasonable arrangement of the film placement is mainly to ensure the uniformity of the longitudinal and lateral loads in the electric furnace, that is to say, the placement of the glass placement of each furnace and the gap time of each furnace should be uniform.
Secondly, the glass should be cooled at the fastest cooling rate possible. The cooling rate depends on the thickness of the glass and other properties of the glass. The cooling of the front and back sides of the glass should be balanced; the ideal cooling medium in the cooling stage of the tempering process is dry cold air, unit The approximate cooling capacity of the area is determined, so the cooling capacity required for 5mm glass is more than twice that of 6mm glass.
Finally, the glass must keep moving during the tempering process, and there should be no traces of scratches and deformation on the glass surface. This movement includes the hot pendulum movement of the glass in the heating furnace. The hot pendulum movement is to make the heating of all parts of the glass surface uniform; at the same time, it also includes the cold pendulum movement of the glass in the air cooling section to ensure the uniformity of the glass fragments. The original glass must not have scratches, bubbles, etc. These conditions can cause the glass to break.