1、High borosilicate glass is preferred
There are heat-resistant and non-heat-resistant glass pots on the market. The use temperature of non-heat-resistant glass is generally “-5 to 70℃”, and the use temperature of heat-resistant glass can be 400 to 500 degrees higher, and can withstand the instantaneous temperature difference of “-30 to 160℃”. As a tea making + boiling tool, high temperature resistant and light weight high borosilicate glass pot is preferred.
High borosilicate glass has a low coefficient of expansion and will not blow up in the event of a sudden change in temperature; high temperature resistance and acid resistance also make high borosilicate less likely to precipitate harmful substances in the daily use of drinking water.
The weight of high borosilicate glass tea set is much lighter than “raw glass” which contains a lot of heavy metal ions, and it looks different from ordinary glass in appearance, visually detaching it from the hard and brittle feeling of “raw glass”.
High quality high borosilicate glass thickness uniform, sunlight is very transparent, refractive effect is good, and the sound of knocking crisp.
2, the glass is not the thicker the better
Thick glass cups to hold cold food is appropriate, hot drinking glass thin than thick good.
Thick glass cups because of the mechanism, in the manufacturing process of “annealing treatment” (so that the tea set temperature slowly and naturally drop, completely eliminate stress) is not as good as blowing thin glass cups. Thick glass does not dissipate heat as fast as thin glass, and when boiling water is poured into it, the inside of the cup wall is heated first and expands rapidly, but the outside does not expand simultaneously, so it breaks. Thin glass cup into the boiling water, heat quickly spread, the cup evenly synchronized expansion, it is not easy to burst.
High borosilicate glass is also generally not made very thick, because many tea sets can be heated by open fire, the glass is too thick, insulation is too good, it will not be able to play well the effect of open fire heating insulation. Article Source.
However, impact resistance is also a very important indicator, you can not say that you can withstand high temperatures regardless of the impact resistance, too thin glass impact resistance is relatively weak. Therefore, the thickness of the heat-resistant glass tea set is developed after comprehensive professional consideration, too thin or too thick are not recommended for purchase.
Also, the most likely to occur in the various articulated parts of the internal stress is not eliminated is also a common reason for bursting. In the purchase should also pay attention to the handle, spout and other articulation is smooth and natural.
3, the tightness of the lid should be appropriate
When buying a glass pot, check the tightness of the lid and the neck of the pot. If the lid and the neck are too loose, they will easily fall off when you use them. And if it fits absolutely, it is also easy to jam, and also easy to cause damage.
Therefore, the lid and the body of the glass pot should maintain a certain degree of looseness, and the fact that the lid is not tight does not mean that it is of inferior quality.
Furthermore, glass teaware is not a pressure-resistant container that can withstand pressure, if the lid is too tight and too sealed, then when the internal temperature changes (whether it is naturally cooled or heated by an open fire), the air part will undergo thermal expansion and contraction, and the air pressure difference cannot be balanced, then the whole glassware becomes a pressure vessel, and an explosion will occur if the pressure-resistant load is exceeded.
Although the lid can not be completely covered tightly does not affect the normal use of the tea set, but in order to meet the psychology of people do not cover tightly do not worry, there are many glass tea sets on the market with the lid is a combination of bamboo lid + sealing ring, is not a very good choice.
4, pay attention to the cup mouth or cup bottom of the small lump
This lump, called “glass drop” in production terminology, is a feature of handmade glass products after fully forming, cutting off the end part of the excess glass solution, which is a feature of handmade glass before the furnace.
Leaving the closing at the mouth of the glass or pot can prevent the absolute absorption between the glass parts and avoid the situation described above where the high air pressure inside the pot cannot be released during the heating process, causing a burst. However, for aesthetic reasons, there are many handmade glass tea sets that deliberately leave the glass drops at the bottom of the cup.
This is a phenomenon unique to glass teaware using the industry’s centuries-old pre-furnace blowing process, which is normal and exists on all hand-blown glassware, and is an important feature of the naked eye to distinguish handmade glass from mechanism glassware.
5、Allows handmade traces or small bubbles
Quality glass teaware is made of pure materials, such as impure materials, the glass will produce lines, bubbles, sand defects. Ripple, refers to the surface of the glass appears stripes; bubble, refers to the glass appears small cavities; sand, refers to the glass contains no molten white silica sand. These defects will affect the expansion coefficient of the glass, which will easily make the glass cracking phenomenon, and may even occur due to the high temperature and automatic blowing up.
Of course, the number and size of bubbles is a reflection of the quality, but the probability of producing “no manual traces without any small bubbles” in a high-temperature processing environment is almost zero, and even the most expensive heat-resistant tea sets will have the same situation. However, as long as it does not affect the beauty and use, we should allow some unavoidable manual traces and small bubbles to exist.
Post time: Aug-06-2021