Home page

Why does the glass from the Foshan glass source factory need to be tempered? Do you know the principle of tempering?

Release time:

Dec 10,2024

　　The mean value treatment of glass (or homogenization treatment) mainly targets specific types of glass products such as tempered glass. Its principle and purpose are as follows:

　　1. Principle

　　Mean value treatment, also known as homogenization treatment or thermal immersion treatment, primarily involves specific heat treatment of tempered glass to improve the internal composition and structural uniformity. Specifically, this treatment involves heating tempered glass to a certain temperature (usually 290℃±10℃) and maintaining it for a period (generally several hours), allowing impurities or stress regions such as nickel sulfide (NiS) within the glass to undergo phase transformation or expansion, thereby causing defective glass to break prematurely in the factory, preventing spontaneous breakage during installation and use.

　　2. Purpose

　　Reduce spontaneous breakage rate: During the production of tempered glass, impurities such as sulfur and nickel may be mixed in, which can generate nickel sulfide at high temperatures. Since nickel sulfide has different crystalline forms at high and low temperatures, rapid cooling during the tempering process may lead to incomplete phase transformation, resulting in spontaneous breakage during subsequent use. Mean value treatment promotes the complete transformation of nickel sulfide into a low-temperature stable phase, effectively reducing the spontaneous breakage rate of tempered glass.

　　Enhance safety: Tempered glass that has undergone mean value treatment has eliminated internal defects and stress concentration areas, significantly improving its safety. Even when subjected to adverse factors such as external impact or temperature changes during use, it can maintain high stability and durability.

　　Optimize performance: In addition to reducing the spontaneous breakage rate, mean value treatment can also optimize other performance parameters of tempered glass to some extent, such as thermal stability and mechanical strength. These performance enhancements allow tempered glass to exhibit better overall performance in various application scenarios.

　　3. Process

　　The process of mean value treatment generally includes three stages: heating, holding, and cooling.

　　Heating stage: Place the tempered glass in a homogenization furnace and gradually heat it to the target temperature (290℃±10℃) at a certain heating rate (usually not exceeding 1.5℃/min). During the heating process, it is necessary to ensure that the surface temperature of the glass does not exceed the allowable range (e.g., 320℃) and to minimize the time the glass surface exceeds 300℃ to avoid unnecessary thermal damage.

　　Holding stage: Once all the glass reaches the target temperature, the holding stage is initiated and maintained for a period (usually several hours). The purpose of holding is to ensure that impurities such as nickel sulfide within the glass have sufficient time to complete the phase transformation or expansion process.

　　Cooling stage: After the holding is completed, the cooling stage begins, allowing the glass to gradually cool to room temperature. During the cooling process, the cooling rate needs to be controlled to avoid generating excessive stress or cracks within the glass.

　　In summary, the principle of mean value treatment of glass is to improve the internal composition and structural uniformity through a specific heat treatment process, thereby reducing the spontaneous breakage rate, enhancing safety, and optimizing performance. This process is of significant importance in the production of specific types of glass products such as tempered glass.

What is the status of Foshan craft glass high-end glass decoration design in the field of design?

What is the price for custom processing of craft glass in Guangzhou? Is the light transmittance of Tiffany glass good?