As we know, lead is harmful to the human body. Thus when we buy a glass cup, we are all concerned about whether the glass contains lead or not. How can we identify lead-containing glass and lead-free glass? We need to distinguish them from the material part.
First of all, there are kinds of materials for making glass. Normal glass is made of soda-lime glass material, which is composed of silicon dioxide. High-grade glass manufacturers generally use high borosilicate. Glass cups, such as French bow and arrow glasses. They are widely used in solar energy, pharmaceutical chemicals, food and beverage appliances, etc. They have good performance in heat resistance, wear resistance, and drop resistance. There is also a crystal glass cup mainly made of crystal glass.
The glass cup contains lead glass, which is called lead crystal. The Glass material contains 24% lead or more, was called Full lead crystal while the lead crystal contains lead below 24%. The benefits of adding lead to glass are heavier, textured, more transparent, clear and bright. The glass material has a high refractive index, looks more like crystal-clear. It has metallic sound when struck, which is beautiful and pleasant. This kind of glass material is also more expensive, and it is generally used in crafts gifts.
High borosilicate glass (also known as hard glass), which has coefficients of thermal expansion of the line (3.3 ± 0.1) × 10-6 / K, is also known as "borosilicate glass 3.3". It is a special glass material with low expansion rate, high-temperature resistance, high strength, high hardness, high light transmittance, and high chemical stability. This material is first of all non-toxic, healthy and resistant to severe temperature difference Injecting hot water or ice water to rupture.
Getting to know well for the material of the glass, however, how do we distinguish between various materials when purchasing glasses?
The price is first.
Since the price of borosilicate glass and crystal glass is relatively expensive, comparing the price when choosing the glasses.
Read the product introduction.
The high-end glass cups manufacturers will definitely indicate the main components of their products in their product descriptions so that they can distinguish which crystal glass and which are high borosilicate glass.
In fact, we also can distinguish between crystal glass and ordinary glass in terms of sound, feel and gloss.
1. Sound. tap the glass cup with your fingers. The crystal glass can make a metal sound and it sounds more pleasant than ordinary glass.
2, Feel. crystal glass is thicker and heavier, compared with ordinary glass, there are obviously different.
3, Tongue. crystal glass even in the summer with the tip of the tongue will have a cold and cool feeling and vice versa.
4, luster. crystal glass's refractive index is particularly good and can absorb the gloss, put the glass in the sun, no matter which angle you will release beautiful brilliance.