Types of glass

Crystal glass

Crystal glass is made by boiling and dissolving silicon and lead oxide together. Due to its high permeability, it can be made into all kinds of handicrafts and is very popular. According to EU standards, crystal glasses are divided into three categories: lead-free, medium lead (lead oxide content of 24%) and high lead (lead oxide content of 36%).

However, scientific research shows that long-term contact between metal lead and acidic substances will produce chemicals harmful to human body. Therefore, the relevant departments of the European Union have banned the production of lead crystal glasses since 2000.

Now, we use the high-quality potassium carbonate purified from oak ashes, and melt it into quartz sand glass solution to form another kind of crystal glass, namely potassium glass, also known as "forest glass", and surpass the lead crystal glass to become the best crystal glass in the world.

Crystal glass belongs to low expansion coefficient material, which is not resistant to high temperature and sudden cold and heat.

Colored glass

When melting glass, a small amount of glass colorant can be added to make all kinds of colored glass.

Copper oxide or chromium oxide produces green;

Cobalt oxide produces blue;

Manganese dioxide produces purple;

Tin dioxide or calcium fluoride produce milky white;

Uranium compounds produce yellow green fluorescence;

Colloidal selenium produces red jade color;

Colloidal gold produces red, purple or blue;

Cuprous oxide produces red, green or blue;

Ferrous compounds produce green color and black color when they are abundant;

Iron compounds produce yellow.

The glass will react with acid and alkali, and the color in the glass will react with it. The components in the color need special attention.

Reminder:

Do not use colored glassware to contain vinegar and vegetables, not to mention alkaline cleaning.

High borosilicate glass

High borosilicate glass (also known as hard glass) is a kind of glass with sodium oxide, boron oxide and silicon dioxide as the basic components, in which boron content is 12.5-13.5% and silicon content is 78-80%. It belongs to the high temperature resistant glass in borosilicate glass. The high borosilicate glass has a very low coefficient of thermal expansion, which is (3.3 ± 0.1) × 10-6 / K, about one third of the ordinary glass, and can withstand 200 degree temperature change. Even if it is broken due to the rapid or uneven temperature change, the cracks of high borosilicate glass tend to be larger rather than crushed. 

Compared with ordinary glass, high borosilicate glass has no toxic side effects. Its main performance indexes have reached the international ISO standards: acid resistance, alkali resistance, water resistance, superior corrosion resistance, good thermal stability, chemical stability and electrical performance, so it has the characteristics of chemical corrosion resistance, thermal shock resistance, good mechanical performance, high temperature resistance, etc. Its good performance has been widely recognized by all walks of life in the world, and developed countries such as Germany and the United States have carried out more extensive promotion.

High borosilicate glass is widely used in various fields such as solar energy, chemical industry, aerospace, military, pharmaceutical packaging, electric light source, technological ornaments, etc. it can be made into lamps, telescope pieces, stage light reflecting cups, roller washing machine observation windows, microwave ovens, heat-resistant tea sets, dining utensils, solar energy collector tubes, etc.

Reminder:

If you want to buy glass dining utensils, please consult with the merchants to see if they are resistant to sudden cold and heat, and if they can be used in microwave ovens, refrigerators, dishwashers and disinfecting cabinets.

Toughened glass

Toughened glass is obtained by cutting ordinary annealed glass into required size, heating it to about 700 degrees near the softening point, and then cooling it quickly and evenly.

Feature 1: Safety

When the glass is damaged by external force, the fragments will become small blunt angle broken particles similar to honeycomb, which is not easy to cause serious injury to human body, so it is called "safety glass".

Feature 2: high strength

The impact strength of toughened glass with the same thickness is 3-5 times that of ordinary glass, and the bending strength is 3-5 times that of ordinary glass. However, toughened glass has the possibility of self explosion (self rupture). According to industry experience, the self explosion rate of ordinary toughened glass is 1-3 ‰.

Feature 3: thermal stability

Toughened glass has good thermal stability. It can bear three times of the temperature difference of ordinary glass and can bear 300 ℃ temperature difference.

Toughened glass is often used in building decoration industry (doors and windows, etc.), furniture manufacturing industry (glass tea table), home appliance manufacturing industry (color TV, etc.), electronic instrument industry (mobile phone, etc.), automobile manufacturing industry (windshield), daily products industry (glass kitchen board, etc.), special industry (military glass).