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Home / News / Industry News / What is the production process of Heat soaked glass? How does it reduce the risk of spontaneous rupture?
The production process of heat-soaked glass involves subjecting tempered glass panels to an additional heat treatment process to reduce the risk of spontaneous rupture caused by nickel sulfide (NiS) inclusions. The goal is to detect and eliminate glass panels with potential defects before they are installed, thereby enhancing the safety and reliability of the glass in architectural and structural applications. Here's how the production process of heat-soaked glass works and how it reduces the risk of spontaneous rupture:
Production Process of Heat-Soaked Glass:
1. Tempering: The production process begins with the fabrication of regular annealed glass sheets. These sheets are then subjected to a tempering process, during which they are heated to a high temperature and rapidly cooled. This process creates tempered glass, which is stronger and more impact-resistant than regular annealed glass.
2. Inspection and Selection: After the tempering process, the glass sheets are carefully inspected for any visual defects or imperfections. The sheets that pass inspection are then selected for heat soaking.
3. Loading and Heating: The selected tempered glass panels are loaded onto racks or trolleys, which are placed inside a heat-soaking furnace. The furnace is heated to a specific temperature, typically around 290-300°C (554-572°F).
4. Dwell Time: The glass panels are held at the elevated temperature for a certain period, typically a few hours. During this dwell time, any nickel sulfide inclusions present within the glass may expand.
5. Stress Relaxation: If a glass panel contains a nickel sulfide inclusion that is of a critical size or position, it can create internal stress within the glass. The heat soaking process accelerates the expansion of these inclusions and increases the chances of stress-related breakage.
6. Potential Breakage: Glass panels that contain nickel sulfide inclusions and are at risk of spontaneous rupture due to stress may fracture during the heat soaking process.
7. Cooling and Inspection: After the dwell time, the furnace is gradually cooled down. The glass panels are then carefully inspected. Any panels that have broken during the heat soaking process are removed and discarded.
How Heat-Soaked Glass Reduces the Risk of Spontaneous Rupture:
The primary mechanism behind the reduction of the risk of spontaneous rupture in heat-soaked glass is the accelerated expansion of nickel sulfide inclusions. These inclusions, which are tiny impurities within the glass, have the potential to slowly expand over time due to temperature changes, leading to fractures.
During the heat soaking process, the elevated temperature causes any nickel sulfide inclusions present within the glass to expand at an accelerated rate. If an inclusion is of a critical size or position, it can create internal stress within the glass. Glass panels that contain inclusions susceptible to spontaneous rupture are more likely to break during the heat soaking process itself.
By conducting the heat soaking process, glass panels with potential defects, including nickel sulfide inclusions, are detected and eliminated before they are installed. This significantly reduces the risk of spontaneous rupture and enhances the safety and reliability of heat-soaked glass in architectural and structural applications.
