Not all glass is heat resistant, do you know that?
[China Glass Network] Glass, as a packaging material for food, is increasingly used in people's daily lives. As consumers' awareness and requirements for food safety gradually increase, their safety performance is also receiving increasing attention. Recently, the Shanghai Municipal Quality Supervision Bureau organized relevant quality inspection agencies to conduct special supervision and spot checks on the glass products for food contact sold in the city. This time, a total of 35 batches of products were inspected, and 11 batches of products were not qualified. Among them, 5 batches of unqualified external surface temperature, 1 batch of unqualified capacity, 2 batches of external surface temperature and capacity were unqualified, and heat-resistant rapid change performance and The batch state was unqualified for 1 batch, and the thermal shock resistance temperature and the inner surface water resistance were not qualified for 2 batches. This spot check examined the following items for food contact glass products: lead precipitation, arsenic precipitation, strontium precipitation, cadmium precipitation, thermal shock resistance temperature, internal stress, birefringence optical path difference, inner surface water resistance , outer surface temperature, capacity, heat-resistant rapid change performance, chip state, heat shock resistance temperature, and the like. The thermal shock resistance temperature is a basic index of heat-resistant glassware, because most of the heat-resistant glass belongs to the borosilicate glass series, and the borosilicate glass has a small thermal expansion coefficient, and has good characteristics of high temperature resistance and temperature-resistant rapid cooling and rapid change. The unqualified item is generally due to the problem of glass material. The heat-resistant glass product has good thermal stability, high heat-resistant temperature and high production difficulty, and its manufacturing cost is 2 to 3 times higher than that of ordinary material glass. Failure of this item may result in injury to the user. The two indicators of temperature resistance and fragmentation are important safety indicators for tempered glassware. Products with poor heat-resistance and rapid-change performance may cause tempered glassware to burst due to rapid temperature changes, which may cause human injury. The failure of these two indicators is mainly due to incomplete or substantially no tempering. In this spot check, these two unqualified products are basically not tempered, and ordinary glass products are sold as tempered glass products, and there is a suspicion of deceiving consumers. The water resistance of the inner surface is a safety indicator. The project reflects the physical and chemical properties of the glass. The products with poor water resistance on the inner surface are easy to precipitate alkali metal ions when used, which affects the quality of the food. The failure of the project is generally due to the problem of the glass material, the chemical stability of the heat-resistant glass products is good, and such unqualified conditions can only be produced by using poor glass materials. The Shanghai Quality Supervision Bureau reminds consumers that when purchasing, it should be noted that according to the current national and industrial standards, glassware is divided into ordinary glassware, heat-resistant glassware and tempered glassware according to different manufacturing processes. The applicable standards are also different. The heat-resistant glassware is suitable for GB17762 "Safety and Hygienic Requirements for Heat-Resistant Glassware". The tempered glassware is suitable for QB/T4064 "Tempered Glassware for Catering". When consumers purchase different glassware, pay attention to the implementation standards of the product labeling. Different glassware has different characteristics. Tempered glass has good impact resistance, but it is not heat-resistant. Generally, it cannot be used for open flame. It has been clearly stipulated in Japan and other countries that tempered glass cannot be used in microwave ovens and ovens; heat-resistant glass has good It is suitable for use as a food processing container in the kitchen and can be directly used in microwave ovens and ovens. Consumers can choose glassware according to their own needs. The tempered glassware package is marked with the standard logo on the standard, with the words "tempered glassware" and "TEMPERED". At present, the concept of "heat-resistant glass tableware cookware" is still unclear. China's regulations do not require merchants to mark on the goods. Therefore, when purchasing heat-resistant glassware, pay attention to the product material, use environment and safety attention. Matters, etc. The manufacturing cost of heat-resistant glass products is higher than other products. Consumers should consider the authenticity if they find the nominal heat-resistant glass at the time of purchase but the price is very low. Kids Slipper Socks,Kids Home Socks,Kids Indoor Socks,Slipper Socks For Kids Jingjiang Pingdong Import&Export Co.,Ltd , https://www.jjpdsocks.com