[China Glass Net] Thermal cracking of architectural glass is a multi-factor problem. It can be divided into main influencing factors and non-main influencing factors on a general basis, depending on the performance of the glass itself and the external environmental conditions and complexities. Non-primary factors may also play a major role, which is to be specifically analyzed for the application conditions. There are three types of causes of thermal cracking in the glass itself: solar radiation, applied loads, and design factors. In addition to these three reasons, the glass and the frame as a whole have structural and manufacturing effects. The thermal cracking of building glass is a comprehensive problem. It is necessary to comprehensively consider the role of various factors, and to exclude the secondary factors from the actual elimination of the project and control the main factors. In general, there are three main factors that restrict glass thermal cracking: Men'S Wear,Men'S Tee Shirts,Men'S Short Sleeve Tee Shirts,Men'S Brief Shorts SHAOXING SOYONG TRADING CO., LTD. , https://www.cn-soyong.com
1. The heat absorption rate of glass The mechanism of thermal explosion is that the glass absorbs infrared radiation in the sunlight, its temperature rises, and a temperature gradient is formed between the cold end of the edge, causing non-uniform expansion or restraint to form thermal stress. Further, crack propagation occurs in the weak portion. Therefore, the absorption rate of infrared light by glass itself is a key factor. Since the heat absorbing glass has been widely used, the problem of thermal cracking has been highlighted. Generally, the heat absorption rate of the heat absorbing glass is between 20 and 40%. When using the design of the heat absorbing glass, it is necessary to make a comprehensive evaluation of the use environment, such as the orientation of the glass, the temperature of the environment, the frame and the wall. The heat conduction situation, etc., should pay special attention to the thermal burst caused by the temperature difference. The glass absorbs heat energy, and its own temperature rises. The greater the temperature difference from the lower temperature frame and wall, the greater the risk of thermal cracking. Experience tells us that thermal cracking usually does not occur in the tropics, but in the southeastern glass of the cold zone or temperate zone, and the thermal burst in the morning and morning is more, because the ambient temperature is low, and the glass absorbs infrared radiation and is easy to be edged. The part forms a large temperature gradient. In the above case, the heat absorbing glass is used to calculate the heat absorption rate and the surface size.
2. The surface of the glass The larger the surface of the glass, the greater the deformation after thermal expansion, and the greater the restraining reaction force, which in turn causes greater thermal stress and increases the probability of thermal cracking. At the same time, the larger the surface size, the more susceptible to the larger additive effect of other loads. Therefore, in the pursuit of the decorative effect of the large panel glass, comprehensive consideration should be given to the comprehensive effects of wind load, thermal stress, frame deformation, self-weight and assembly stress. After the surface of the heat absorbing glass exceeds 2m2, the corresponding improvement measures should be proposed for the frame constraint.
3. The processing quality of the glass edge indicates in the thermal stress analysis that the cracking generally starts from the edge of the glass, the tensile stress at the edge is larger, and the processing defects at the edge are more serious. Therefore, improving the processing quality of the edge is to improve the architectural glass. One of the key factors in resistance to thermal bursting. When there is a defect in the edge of the glass, the tensile strength of the glass is greatly reduced, and the edge of the glass is preferably finely ground during processing and installation, and the glass with severe defects is removed.