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Not all the glass is heat resistant.

  • Author:Fanyumaoyi
  • Source:Chinamirenufacturer. com
  • Release on :2017-06-26
  Glass as a food packaging utensils, more and more used in people's daily life. With the increasing of consumers ' awareness and demands on food safety, their safety can be paid more and more attention.
  Recently, the Shanghai Municipal Bureau of Quality Supervision organization of relevant quality inspection agencies of the city sales of food contact with glass products conducted a special supervision spot checks. This is a total of 35 batches of products, unqualified 11 batches of products, of which the surface temperature unqualified 5 batches, capacity unqualified 1 batches, outside the surface temperature and capacity are unqualified 2 batches, heat-resistant shock and fragmentation of the performance and the status of the unqualified 1 batches, heat-resistant impact temperature and water resistance of the internal surface is unqualified 2 batches.
  This test examines the following items of glass products for food contact: lead precipitation, arsenic precipitation, antimony precipitation, cadmium precipitation, heat shock temperature, internal stress, birefringence light path difference, the inner surface water resistance, external surface temperature, capacity, heat shock resistance, debris status, thermal impact temperature and so on.
  Heat-resistant impact temperature is the basic index of heat-resistant glassware, because the heat-resistant glass is mostly borosilicate glass series, the thermal expansion coefficient of borosilicate glass is small, and has good high-temperature and temperature-resistant quenching and heat change characteristics. The project is not qualified generally because of the problem of glass materials, heat-resistant glass products good thermal stability, heat-resistant temperature high and difficult to produce high, its manufacturing costs than ordinary materials glass 2 to 3 times times higher. The failure of the project may cause harm to the user.
  The performance of temperature-resistant and the fragmentation of the two indicators are very important to the tempered glass containers safety indicators. Heat-resistant products with poor performance will cause the temperature of the tempered glass containers burst, easy to cause human injury. The failure of these two indicators is mainly due to the fact that the tempering is not completely or basically not tempered. The two unqualified products are basically not tempered, the ordinary glass products as tempered glass products to sell, there is a suspicion of cheating consumers.
  Water resistance of the inner surface is a safety index, the project reflects the physical and chemical properties of glass, good or bad, the inner surface of poor water resistance products easy to precipitate alkali metal ions, affecting the quality of the food. The project is not qualified generally because of glass material problems, heat-resistant glass products chemical stability is good, only the use of poor glass raw materials will produce such unqualified.
  Shanghai Quality Supervision Bureau to remind consumers, when purchasing should pay attention to the current national and industry standards, glassware is divided into ordinary glassware, heat-resisting glassware and tempered glass utensils according to different manufacturing processes, applicable standards are not the same, heat-resistant glassware applicable to GB17762 "heat-resistant glass utensils safety and hygiene requirements", toughened glass utensils applicable to Cb T4064 "dining with tempered glass utensils." Consumers in the purchase of different glassware, pay attention to observe the implementation of product labeling standards.
  Different glassware have different characteristics,GlassGood impact resistance, but not heat, generally can not be used for open flame, in Japan and other countries have made it clear that tempered glass can not be used in microwave ovens and ovens; heat-resistant glasses have good temperature and temperature-resistant hot and cold heat change characteristics, suitable as food processing containers in the kitchen, can be directly placed in microwave ovens and ovens. Consumers can choose according to their own needs of glassware, tempered glass containers marked with standard on the label map, there are "tempered glass utensils" and "Tempered" words. At present, the concept of "heat-resistant glass tableware cooker" is still not clear, China's laws and regulations do not require businesses to label goods, therefore, in the purchase of heat-resistant glassware, we should pay attention to products Express product materials, use of the environment and safety precautions. Heat-resistant glass products manufacturing costs relative to other products to be high, consumers in the purchase if they find the nominal heat-resistant glass but the price is very low, to consider its authenticity.
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