Magical and sacred glassware - heat-resistant glass tableware and cookware

With the gradual improvement of consumers' awareness of health and safety and their deepening understanding of the characteristics of glass products such as health, safety, environmental protection, hygiene, convenience, transparency, beauty and easy cleaning, a large number of tableware and cookware made of heat-resistant glass have entered hotels, restaurants and the daily life of ordinary people. Its heat resistance, product diversification, serialization and aesthetic appearance have improved people's quality of life and enriched their lives.

What is heat-resistant glass?

Heat-resistant glass is a type of glass that has a strong ability to withstand thermal shock caused by sudden heating and cooling (with a small coefficient of thermal expansion) and a high service temperature (high strain temperature and softening temperature). It is also known as hard glass.

Generally speaking, heat-resistant glass is also another name for high borosilicate glass, but microcrystalline glass, high alumina glass and some special glasses are also classified as heat-resistant glass due to their good heat resistance.

The characteristics of heat-resistant glass

The main property of heat-resistant glass is its thermal shock resistance. It can be used normally in a high-temperature environment of 550℃. Its unique physical and chemical properties determine that this glass is a truly all-round and widely used material. The main features are:

(1) It has excellent thermal properties, good thermal shock resistance and a small coefficient of expansion.
(2) It has a high light transmittance and surface flatness;
(3) It has a relatively high surface hardness and can prevent scratches. Its density is about 12% lower than that of ordinary sodium-calcium-silica glass, generally 2.3g/cm ³. When used as building glass, especially for high-rise buildings, it will significantly reduce the overall weight of the building.
(4) It has good acid and alkali resistance; It also has excellent water resistance and will not cause crack expansion due to the action of water molecules in humid air, which is two grades higher than ordinary sodium-calcium-silica glass.

The application fields of heat-resistant glass

Heat-resistant glass can be widely applied in various fields based on different properties such as glass types, uses, and heat resistance temperatures: it is mainly used to manufacture heat-resistant glassware, burners, and measuring vessels for laboratories. It can also be used to manufacture industrial reaction tanks, reaction kettles, complete sets of chemical equipment and conveying pipelines, etc. In civilian applications, it is used to manufacture baking trays, soup POTS, various tableware for dining, etc.

Heat-resistant glass tableware and cookware

Heat-resistant glass tableware and cookware refer to tableware and cookware made of heat-resistant glass used on dining tables and in kitchens, including glass containers and LIDS.

Heat-resistant glass tableware and cookware are made of high borosilicate glass, microcrystalline glass or aluminosilicate glass, with an expansion coefficient of less than 65×10-7/K (0-300℃).
Heat-resistant glass tableware and cookware are further classified into heat-resistant and super-heat-resistant types based on their heat resistance temperature differences. Those with a heat resistance temperature difference between 120℃ and 400℃ are heat-resistant, while those with a temperature difference above 400℃ are super-heat-resistant.
Heat-resistant glass tableware and cookware can be classified into open flame utensils, hidden flame utensils and hot water utensils.
Glassware for open flames: (1) Mainly composed of ultra-low expansion microcrystalline glass, with a thermal shock strength of over 400℃, it is mainly used for direct open flame heating, cooking, and situations where it is subjected to rapid heating and cooling. For example, frozen food can be directly heated and cooked together with the container using an open flame, a closed flame, or an electric stove.
(2) It has a thermal shock strength of over 150℃ and is mainly used in situations where direct open flame heating or cooking is required.
Glass products for dark flames: With a thermal shock strength of over 120℃, they are mainly used in heating and cooking scenarios where there is no direct open flame. For example: used in microwaves, ovens, etc.

Note: It is also common to see glassware marked with the words "tempered heat-resistant glass or heat-resistant tempered glass" on the market. Tempered glass is a type of strengthened glass that has its mechanical strength and thermal shock strength enhanced through methods such as air cooling and ion exchange after the formation of soda-lime glass. According to the definition of heat-resistant glass, tempered glass does not essentially belong to the category of heat-resistant glass. In Appendix A of the tempered glass standard (GB15763.2), there is such a description: "Due to the presence of tiny nickel sulfide stones in the glass, after heat treatment, some of the stones will undergo crystalline changes over time, increasing in volume and causing microcracks inside the glass, which may lead to self-explosion of the tempered glass." There have also been reports of tempered glassware exploding and injuring people when used in microwave ovens both at home and abroad. Therefore, it is not recommended that consumers purchase tempered glassware for use in microwave ovens or ovens.