How to choose high-quality glass teapots

 1. High borosilicate glass is the first choice
There are heat-resistant and heat-insensitive glass pots on the market. The use temperature of heat-resistant glass is generally "-5 to 70°C", and the use temperature of heat-resistant glass can be 400 to 500 degrees higher, and it can withstand an instantaneous temperature difference of "-30 to 160°C". As a tea-making + tea-making tool, a high-temperature resistant and light borosilicate glass pot is the first choice.
The high borosilicate glass has a low expansion coefficient and will not explode in the case of sudden temperature changes. The high temperature resistance and acid resistance also make it difficult for the high borosilicate glass to precipitate harmful substances in the daily drinking water.
The weight of high borosilicate glass tea set is much lighter than "green glass" which contains a lot of heavy metal ions, and it looks different from ordinary glass in appearance, and it is visually separated from the hard and brittle feeling of "green glass".
The high-quality borosilicate glass has uniform thickness, is very transparent under sunlight, has good refraction effect, and the percussion sound is clear.
2. The thicker the glass, the better
Thick glasses are suitable for cold food and beverages, and hot drinking glasses are thinner than thicker.
Because thick glasses are machine-made, the "annealing" in the manufacturing process (allowing the temperature of the tea set to slowly drop naturally and completely eliminating stress) is not as good as blowing thin glasses. The heat dissipation speed of thick glass is not as fast as thin glass. When boiling water is poured in, the inside of the cup wall is heated first and expands rapidly, but the outer surface does not expand at the same time, so it breaks. When a thin glass is poured into boiling water, the heat is quickly dissipated, and the body of the cup expands evenly and synchronously, so it is not easy to burst.
Borosilicate glass is generally not made very thick, because many tea sets can be heated by an open flame. If the glass is too thick and the heat insulation is too good, it will not be able to achieve the effect of heating and heat preservation by an open flame. Article Source:
However, impact resistance is also a very important indicator. It cannot be said that it can withstand high temperature regardless of impact resistance. The impact resistance of glass that is too thin is relatively weak. Therefore, the thickness of the heat-resistant glass tea set is determined after comprehensive professional consideration, and it is not recommended to buy it if it is too thin or too thick.
In addition, failure to eliminate the internal stress that is most likely to occur in each connecting part is also a common cause of bursting. When purchasing, you should also pay attention to whether the handles, spouts and other joints are smooth and natural.
3. The tightness of the lid should be appropriate
When buying a glass jug, check the tightness of the lid and the neck of the jug. If the lid and neck are too loose, they will easily fall off during use. And if it is absolutely consistent, it is easy to jam and cause damage.
Therefore, the lid and the body of the glass jug must be tight. The tightness of the lid does not mean poor quality.
Furthermore, glass tea sets are not pressure-resistant containers that can withstand pressure. If the lid is too tight and sealed, then when the internal temperature changes (whether it is natural cooling or open flame heating), the air part will expand and contract. If the air pressure difference cannot be balanced, the entire glassware becomes a pressure vessel, and if the pressure load exceeds the pressure load, it will explode.
Although the pot lid cannot be completely closed does not affect the normal use of the tea set, but in order to satisfy everyone's mentality of not being tight, there are many glass tea sets on the market that use a combination of a bamboo lid + a sealing ring, which is a very good one. select.
4. Pay attention to small bumps on the mouth or bottom of the cup
This lump is called "droplets" in production technical terms. It is the final part of the hand-made glass product after it is completely formed, and the excess glass solution is cut off. It is a feature of the hand-made glass in front of the furnace.
Leaving the mouth in the mouth of the cup or the mouth of the pot can prevent the absolute suction between the glass fittings, and avoid the above-mentioned situation that the high air pressure in the pot cannot be released during the heating process and cause bursting. However, for the sake of beauty, there are also many handmade glass tea sets that deliberately leave the glass drops at the bottom of the cup.
This is a unique phenomenon that glass tea sets use the furnace front blowing process that has been passed down for hundreds of years in the industry. It is normal and exists on all hand-blown glassware. It is also an important feature that distinguishes hand-made glass from machine-made glassware with the naked eye.
5. Allow manual traces or small bubbles
High-quality glass tea sets are made of pure materials. If the material is not pure, the glass will have lines, bubbles, and sand defects. Grain refers to the appearance of streaks on the surface of the glass; bubble refers to the appearance of small cavities in the glass; sand refers to the white silica sand that is not melted in the glass. These blemishes will affect the expansion coefficient of the glass, easily cause the glass to crack, and may even automatically explode due to excessive temperature.
Of course, the number and size of bubbles are one of the manifestations of quality, but the probability of producing "no traces of handwork and no small bubbles" under high-temperature processing environments is almost zero. This is also the case for expensive heat-resistant tea sets. But as long as it does not affect the appearance and use, we should allow some unavoidable manual traces and small bubbles to exist.