Be wary of the kitchen killer using glassware to distinguish the material

Glass products have the advantages of transparency, easy cleaning, firmness and corrosion resistance. More and more people are used as daily necessities and food containers, which are loved by consumers. With the advancement of glass manufacturing technology and craftsmanship, the types and ranges of glass products have become wider and wider, and some glass products can be directly used as cookware. At the same time, some consumers have suffered glass burst injuries due to lack of understanding of the specific materials and scope of use of glass products.
At present, the glassware that consumers often come into contact with in their home life mainly include ordinary glass, tempered glass and heat-resistant glass. Most consumers of ordinary glass know that it cannot be used for high temperature heating (oven, microwave oven), but many consumers do not understand the difference between tempered glass and heat-resistant glass. They mistakenly used tempered glass containers for cooking purposes and even caused incidents of tempered glassware after bursting. Tempered glass is an improved product that is tempered and improved on ordinary soda-lime glass to improve mechanical shock resistance, and its thermal shock resistance is limited. Most of the heat-resistant glass belongs to the borosilicate glass series, including glass-ceramics and other varieties. because different
chemical compositions, the structure is also different from ordinary glass or tempered glass. Borosilicate glass has a small coefficient of thermal expansion, good resistance to high temperature and temperature, rapid cooling and rapid changes. It is suitable for use as a food processing container in the kitchen and can be directly used in microwave ovens and ovens. Kitchen heat-resistant glass products mainly include heat-resistant tableware, heat-resistant crisperware and cooking utensils, which can be divided into open fire and dark fire. Heat-resistant glass with ultra-low expansion coefficient, such as glass-ceramic, has a thermal shock strength of more than 400 ° C. It is mainly used for direct open flame heating, cooking and subjected to rapid heating and cooling. The glassware for dark fire has a thermal impact strength of 120 ° C or higher. It is mainly used for heating cooking occasions such as ovens and microwave ovens that are not directly open fire. It is also a common heat-resistant glass product currently on the market, such as borosilicate glass.
According to a survey by the China Consumers Association, there have been many reports of injuries caused by self-explosion of tempered glass in the media at home and abroad. Countries such as Japan have clearly stated that tempered glass cannot be used in microwave ovens and ovens. With the changes in the diet structure and cooking style of consumers in China, consumers have begun to accept glass cookware, and the number has increased rapidly. However, the labeling of glass products on the market is not clear at present. Some operators also intend to confuse the concept, and expand the functions of ordinary tempered glass and even ordinary glass, making it extremely easy for consumers to buy and misuse. Here, the China Consumers Association reminds consumers to pay attention to:
First, ordinary glass can not be used to heat the cooking environment, such as can not be used in the oven, microwave oven, non-homogeneous treated tempered glass, such as in the oven, microwave oven has the risk of self-destruction injury (currently "homogeneous" treatment of tempered glass Mainly used for industrial purposes, such as automotive glass, building doors and windows, furniture, etc.).
Second, at present, there is no such thing as heat-resistant tempered glass products or tempered heat-resistant glass products in the domestic market. Consumers should not be misled when purchasing.
Third, the heat-resistant glass products should be marked with corresponding signs, indicating the use temperature, the scope of use, etc., consumers should pay attention to the above information when purchasing and using. At present, among the heat-resistant glass, borosilicate glass is mostly used, and the heat resistance of the glass ceramic is better.
Fourth, the heat-resistant glass products are obtained by annealing and cooling, and have good thermal stability, high heat-resistant and rapid temperature, high production difficulty, and high manufacturing cost. Consumers who consider the use of nominally heat-resistant glass at a low price are considered for their authenticity.
In addition, glass cookware (tableware) production and management companies are also obliged to make clear the product material, the use environment and safety precautions. It is also necessary for the corresponding appliance manufacturing enterprises such as ovens and microwave ovens to indicate the specific functional requirements and scope of use of the matching heating containers in the instruction manual. Catering companies should also provide consumers with glassware that meets safety requirements.
background knowledge:
Causes of tempered glass self-explosion
The reason why tempered glass is easy to bleed is because in the process of manufacturing, it often becomes a mixture of nickel sulfide component (NiS) that cannot be found by the naked eye. This kind of nickel sulphide will cause tempered glass to occur under the change of ambient temperature and glass. Matching the larger expansion, that is, breaking the balance between many stresses inside the glass, the glass may crack, causing the phenomenon of glass self-explosive flying. The flat-plate tempered glass has strong mechanical impact resistance, but after the tempering treatment of the shaped vessels such as cookware (tableware), the self-explosion rate is high and the safety is poor due to the complicated shape and uneven stress during external heating. Although it is possible to increase the process of "homogeneous" treatment of tempered glass and reduce the self-explosion rate, the current "homogeneous" treatment of tempered glass is mainly used in industrial fields, such as automobile glass, building doors and windows, furniture accessories, and the like.
Regulations on the management of glass cookware (tableware) in countries around the world
Some countries in the United States, Japan, and Europe started using glassware as the main kitchen utensils very early. The problem has arisen more and earlier. To this end, some countries have issued regulations on the production, classification and use of glassware, clearly defining what is heat-resistant glass and its key performance parameters. Some have imposed restrictions on the scope of use of tempered glass. For example, the "Glass Food Maker Quality Mark" was formulated by the Japanese government in 2001.