Glass can be divided into water cup, wine cup and tea cup according to function. According to different categories, glass can be divided into high borosilicate heat-resistant glass, crystal cup and double-layer glass. Because the performance and quality of these cups sold on the market are different, their quality directly affects our health. What kind of glass is good? How can you tell whether a glass is good or bad?
1. The thickness should be consistent: when selecting, observe the cup against the light. If the light feeling is consistent and integrated, it indicates that the thickness is consistent; If the difference between light and shade is too large, the thickness is inconsistent. If the shoulder of the cup is too thin, it is generally not easy to find, but if you observe the light, you will find that the too thin place is too bright.
2. Beautiful and practical appearance: the surface should be smooth, the cup gloss should be good, the geometry should be flat, and the cup cover should not be too loose or too tight.
3. The quality of materials should be pure: if the quality of glass materials is not pure, there will be lines, bubbles or sand.
(1) Lines: there are stripes and coarse lines on the glass surface, which can be felt by hand, and the fine lines can be seen only when facing the light.
(2) Bubble: a small cavity formed by wrapping air in the glass. The bubble looks like a small circle from the outside in the deep part of the glass.
(3) Sand: white granular silica sand embedded in the glass without melting, also refers to other granular impurities.