The causes and solutions of pitting defects in tempering furnace operation

Different from the irregular pitting which caused by insufficient cleanliness, pitting defects cause from poor equipment conditions which have obvious regular charateristics, mostly presenting dot like or linear marks related to equipment's operation trajectory. The condition of equipment components that are in direct contact with glass directly affects the formation of pitting.

The core problem usually lies in the roller system that carries the glass. Over time, the surface of the rollers may experience wear, oxidation, or slight pits due to high temperatures and friction. In addition, special attention should be paid to equipment damage caused by improper process parameters. When an excessive amount of the process gas sulfur dioxide is introduced, it will form raised spots on the roller surface, which in turn leave corresponding pitting on the surface of the tempered glass.

Therefore, establishing a preventive equipment maintenance system is crucial. The primary task is to implement a regular inspection and maintenance plan for the roller system, using professional measuring tools to detect the flatness and concentricity of the rollers, and promptly replacing or polishing rollers that are excessively worn or severely damaged on the surface. Secondly, it is necessary to accurately control and monitor the injection volume and uniformity of sulfur dioxide, strictly limiting it within the range required by the process to avoid damage to the rollers.