01 Overview of Glass Tempering Furnaces
A glass tempering furnace, also known as a glass tempering unit, tempering equipment, or tempering system, is used to strengthen glass through a thermal process. These furnaces can be categorized as batch-type or continuous, vertical or horizontal, and electric or gas-heated.
To understand insulation requirements for a glass tempering furnace, it is essential to know how the process works. Glass tempering typically involves heating glass to near its softening point (approximately 650°C) followed by rapid air quenching. This process creates a compressive stress layer on the surface and tensile stress inside the glass. When external force is applied, the surface compression counteracts the tension, reducing the risk of breakage and enhancing the overall strength of the glass.
Standard flat glass tempering furnaces vary in size, with common lengths of 4 meters and 10 meters, depending on the dimensions of the glass being processed.
The operating temperature inside the glass tempering furnace reaches about 800°C, achieved using electric resistance heating elements.
02 Insulation Structure of the Glass Tempering Furnace
To prevent contamination of the glass during high-temperature processing, ceramic fiber blankets or modules are not used directly in contact with the glass.
The current standard lining structure for glass tempering furnaces consists of layered SUNTHERM ceramic fiber boards for the roof, walls, and floor. The total insulation thickness is typically 250mm.
03 Technical Advantages
During the heating process, temperature differences between the center and edges of the furnace can lead to uneven stress distribution. While stress patterns cannot be entirely eliminated, a well-designed tempering system can significantly reduce their visibility.
Ceramic fiber boards offer low weight, easy installation, and low thermal conductivity, providing excellent insulation performance. This helps minimize temperature variation, reduces the visibility of stress patterns, and improves the quality and yield of tempered glass products.
