What Is The Reason for Tempered Glass Chipping? Reasons And Solutions for Corner Dropping

Various problems may occur during the operation of the glass tempering furnace, but one problem that troubles many people is the chipping of tempered glass. When tempered glass is formed outside the furnace, the corners fall off as soon as they are touched. The previous process was normal, so what is the reason for tempered glass falling off corners?

1. The Reasons for Corner Falling in Tempered Glass

1.1. Insufficient heating time, low temperature inside the furnace, and low power of the tempering furnace.

1.2. The upper and lower furnace wires are broken.

1.3. Thermocouple temperature detection error, solid-state relay damaged, fuse burned out, circuit problem.

1.4. The glass collided inside the furnace.

1.5. The glass spacing is too small, and the furnace discharge speed is not appropriate, resulting in collision.

1.6. The glass air box has a sudden and high cold air pressure.

1.7. The original glass has bubbles or stones, but in this case, the glass usually breaks during the heating stage.

1.8. Excessive glass grinding or uneven distribution, resulting in excessively fast wafer production speed.

1.9. No hidden cracks were found on the glass edges or openings.

After reading the above content, I believe everyone is clear about what causes corner dropping in glass tempering furnaces. Below, I will explain the solutions to corner dropping in glass tempering furnaces.

2. Solution to Corner Falling in Tempered Glass

2.1. The process parameters of tempered glass are related to heating temperature, heating time, cooling air pressure time, and tempering cooling time. By adjusting the values of each parameter and cooperating with each other, the occurrence of corner dropping in the glass tempering furnace can be reduced. For example, the higher the tempering heating temperature, the shorter the heating time. Generally, the heating time is 40 seconds per millimeter of glass thickness. However, when tempering large plate glass, an additional 10% heating time is required, and when drilling or digging corners, an additional 10% heating time is also required. Therefore, flexibly controlling the heating time and temperature can effectively reduce the occurrence of tempered glass corner dropping events.

2.2. Before entering the tempering furnace, glass is first ground to ensure its appearance and reduce the occurrence of glass breakage, thereby improving the yield of tempered glass. However, during the grinding process, it is also easy to experience edge breakage and corner loss. At this time, the uniform grinding amount and water addition should be adjusted, and the grinding speed should be appropriately reduced.

2.3. Glass is actually a cube, and the heating on its upper and lower surfaces is relatively slow. When tempering large plate glass, the middle of the glass often experiences slow heating. To ensure even heating of the large glass layout, set the temperature of the furnace to a heating curve where the temperature in the middle is 10 degrees higher than the set temperature and the temperature at the edges is 10 degrees lower than the set temperature. The tempered glass in this way is both complete and uniform in particle size.

After understanding how tempered glass falls off corners, we have also mastered the corresponding solutions. The control level of various parameters during the use of glass tempering furnaces is also crucial to maintaining the quality of tempered glass.