At present, among all kinds of cups and POTS, the glass is the healthiest and safest cup, and it has become the most widely used cup. There are so many glasses on the market that some are shoddily made. How can I judge the quality of a glass?
1. Look at purity
If the glass material is not pure, streaks, small bubbles and impurities will appear on the glass drinking set.
2. Check whether the thickness of the cup is even.
Look at the cup against the light. If the light feels the same, it blends everywhere, and the thickness is the same. If the shade difference is too big, the thickness is inconsistent. If the cup is too thick, it will heat slowly and crack easily. The cup is too thin, weak and weak.
3. See the material
Generally including ordinary sodium calcium glass, high borosilicate glass, crystal glass and other materials. The temperature resistance of sodium calcium glass is more general, and the heat resistance range must be confirmed before use. High borosilicate glass is pure and transparent, the thermal expansion coefficient is only one third of ordinary glass, can withstand sudden temperature difference, is recognized as a safety glass material. Glass is mostly used in tall glasses, divided into lead crystal glass and lead - free crystal glass. The former is harmful to human health. The latter flicks the cup to produce a pleasant sound and is bright and transparent in color.