The glass toughening industry is undergoing continuous transformation, and the market demand has posed unprecedented challenges to this industry. Glass heat treatment has experienced many significant developments, including the evolution from vertical hanging tempering to horizontal roller hearth furnace, from continuous furnace to reciprocating furnace, the introduction of fused silica ceramic rollers, and the development of hot air assisted heating furnace and Forced convection furnace. This change is always driven by the market, in order to meet the requirements of improving production capacity, flexibility, and glass quality. Today, these market demands continue to be more challenging, including energy-saving glass, updated reflective coated glass, conductive coating, hydrophilic and non hydrophilic glass, ultra-thin glass, ultra-white glass, and complex curved glass. Various specifications and specifications will also become more stringent.
Manufacturing high-quality and deformation free glass requires good process control and internal management. On the basis of ensuring this principle, in order to continue the development of architectural glass and Car glass, it is also necessary to have a thorough understanding of the basic principles and dynamic theory of processing technology. Along with the development of glass products, the tempering process is also developing. This includes improving the efficiency of the tempering furnace, ensuring accurate straightness of the rollers at working temperature, and paying more attention to the cleanliness and operation of the factory building.
Wave shaped deformation caused by ceramic rollers and roller tracks
With the increasing strictness of glass specifications and the implementation of new regulations, especially regarding wave deformation, the interaction between glass and rollers is receiving increasing attention. There are several possibilities that can cause glass deformation: the glass becomes soft due to overheating and sags between rollers; Uneven roller surface in the furnace causes deformation of glass in the furnace; The relationship between glass heating temperature and roller spacing; And roller table eccentricity, etc. The eccentricity of the roller table may be caused by insufficient accuracy of the ceramic roller shaft head, looseness of the shaft head during production, or excessive thermal runout caused by ceramic quality issues.
Roller table collimation TIR
The TIR (total runout) of the roller table is very important, and there are strict requirements for full runout under hot conditions to avoid causing wavy deformation of the glass. Ceramic materials must be homogeneous and amorphous. If the ceramic roller mechanism is uneven or has too much quartz, the ceramic roller is likely to bend or twist at operating temperature. Having good cold full runout does not guarantee good hot full runout. It is very important to know how to measure full runout and how to distinguish whether there are deformed ceramic rollers in the tempering furnace.
Connection method and selection of shaft head
The connection of the shaft head is crucial for maintaining the overall alignment of the roller table. There needs to be a precise fit between the ceramic roller and the shaft head to avoid shaking due to loose fit, but this fit should not be too tight, otherwise excessive stress will break the ceramic roller from the shaft head assembly. When assembled well, the silicone bonded shaft head can work effectively at low temperatures (the shaft head extends out of the furnace at approximately 100 ℃). The design of some ceramic rollers requires an additional Mechanical bond at the shaft head. These keys are backup measures for silicone failure that may occur due to high temperatures. The selection of shaft head structure depends on the structure of the tempering furnace and its application environment.
High precision roller table production of high-quality glass
The glass tempering furnace is designed for
