The double-layer glass cup is made of high borosilicate glass, which has high temperature resistance and corrosion resistance that traditional glass cups cannot match. It does not contain harmful lead to the human body, does not absorb odors, has good health and safety transparency, and is mainly used for insulation and thermal insulation functions, which is highly welcomed by everyone. But have you noticed that there is a vent at the bottom of each double layered glass cup? What is its purpose?

Originally, double-layer glass cups were usually hand blown, with an air vent at the bottom of the outer layer of the cup to release gas during the blowing process, preventing the cup from deforming and exploding. This process is similar to the inner liner of a thermos bottle, which serves as the closing point to eliminate air between the glasses during the production process. It can balance the pressure between the glass when filling hot and cold drinks, allowing air circulation and avoiding the infiltration of water vapor, effectively extending the service life of the glass cup and ensuring safe use. Its main function is to promote air circulation inside the cup and prevent cracking problems caused by pressure.

In summary, the reason why the bottom of a double layered glass cup is designed with air holes is that when the cup is filled with hot water and the air begins to expand, there will be a place to release the air. Otherwise, the cup will explode due to excessive pressure, causing injury to the user. That is to say, the air holes at the bottom of the double-layer glass cup are actually a protective device that can greatly ensure the safety of the glass cup. Therefore, when using the double-layer glass cup, we should try not to touch the air holes at the bottom of the cup casually to avoid damage to the air holes, which is not easy to repair.