introduction
Type, chemical composition and structural characteristics of glass Electric light source glass is one of the main materials for manufacturing light source equipment and electrical components. Since Edison invented electric lights, incandescent lamps, fluorescent lamps, and the like have been widely used. With the rapid development of the light source industry, the glass material industry for electric light sources has also been rapidly developed for the main materials of light sources, and various types of light source glass types have been continuously introduced. Since the electric light source uses lead glass, it is easy to cause pollution. Due to environmental pressures, the glass industry is facing the need to update production processes. The world's three major lighting products manufacturing companies: Philips, Osrom (a wholly-owned subsidiary of Siemens), GE and many of China's large light source glass production plants are also constantly developing new glass brands to meet the needs of the international market. Saving energy, protecting the environment, and meeting people's demands for higher and higher lighting quality are the tenets of green lighting. However, with the advent of various new types of energy-saving electric light sources, the environmental pollution caused by harmful substances in the process of production and use should also attract people's attention.
1 Type, chemical composition and structural characteristics of glass
Glass is usually classified by chemical composition or use. According to the chemical composition of glass, glass can be divided into soda glass, potassium glass, lead glass, borosilicate glass, quartz glass, aluminosilicate glass, microcrystalline glass, imitation cloisonne glass, light color glass, and gold star glass. Sodium soda glass is commonly referred to as ordinary glass. Among the main components, SiO accounts for 72% and Na O accounts for 15%. Its mechanical strength, thermal stability, and chemical stability are poor, but it is easy to melt and process, and its price is low. It is widely used in the manufacture of general window glass, packaging bottles and low-grade daily-use utensils.
1.1 Characteristics of common glass
Potassium glass, also known as hard glass, differs from sodium silicate in that it replaces Na O with Ka O and increases the SiO content. It has better hardness and gloss, and its strength, heat resistance and chemical stability are better than that of soda glass. It is mostly used in the production of chemical instruments and exquisite daily utensils. Lead glass is also called optical glass and crystal glass. Among its main components, SiO accounts for about 68%, and PbO accounts for 15% to 35%. Lead glass can block X-rays, has strong refractive index and gloss, low hardness, easy processing, and can make a pleasant metal sound when struck. Lead glass is best suited for the production of optical instruments, art and high-end utensils.
(3) borosilicate glass
In borosilicate glass, SiO accounts for 80% and BO accounts for 14%. It has high heat resistance and chemical stability (such as good resistance to cold and heat, no pollution and acid and alkali resistance), has good strength, gloss and insulation, and is suitable for the production of high quality physical and chemical laboratory equipment. Cooking utensils (such as heat-resistant glass boilers), electrical appliances (such as electric light source and glass for electronics industry), medicinal glass packaging containers, thermos flasks, thermometers, and chemical anti-corrosion pipes and equipment.
(4) Quartz glass
Quartz glass is known as the “glass king†and its composition is almost SiO. Quartz glass is transparent and opaque. Transparent is made of crystal, and opaque is made of pure quartz sand. It has extremely high heat resistance, chemical stability and high strength, wear resistance and insulation. It can withstand ultraviolet rays, withstand high temperatures of 200 °C, and has a rapid thermal temperature difference of up to 1000 °C. Quartz glass is mainly used to make high temperature resistant devices and special instruments, such as medical ultraviolet germicidal lamps.
(5) Aluminosilicate glass
The primary components of aluminosilicate glass are SiO and Al O . It has high heat resistance, chemical stability and strength, and is often used to make cooking vessels that are heated directly by flame.
(6) Glass ceramics
In addition to the above, the sapphire glass is made of ordinary glass as the basic component, and the glass obtained by adding an appropriate amount of copper oxide and cobalt oxide is used for making decorations such as vases and craft candle holders. The photochromic glass contains a silver halide colloidal photosensitizer, which has the characteristics of being darkened or colored after being irradiated with light, and is commonly used for producing color-changing glasses, optical switches, holograms, and decorative materials. There are two kinds of gold star glass: chrome gold star glass and copper gold star glass. They contain crystals with high refractive index such as chromium oxide and cuprous oxide. They have the characteristics of flashing gold stars and are often used to make decorations and crafts.