The quality of fluorescent products is not only related to the production process and technical equipment, but also closely related to raw materials. The fluorescent lamp is a low-pressure mercury vapor discharge lamp which is sealed by a phosphor coated glass tube and a cathode-mounted core post. After evacuation, mercury is placed and filled with an inert gas such as argon or helium. The glass tube and the stem of the fluorescent lamp made of glass material constitute a sealed container for discharge. Among them, the glass tube of the straight tube type fluorescent lamp for general illumination uses a soda lime glass tube, and the core column is processed by a lead glass tube. The quality of these two glass tubes directly affects the quality of the fluorescent lamp products; while the uniformity of the glass tube dimensions is closely related to the qualification rate of the automatic production line. There are many varieties of fluorescent lamps, and different types of fluorescent lamps use different glass tubes. This paper only deals with the most common fluorescent lamps for general illumination, analyzes the production technology and product quality of the soda-lime glass tubes and lead glass tubes used, and puts forward some suggestions on this basis. I. Current Situation of Glass Tubes for Fluorescent Lamps Glass is a very important material for electric light source products. There are many types of glass, and a large number of glass applications include: soda lime glass, lead glass, borosilicate glass, aluminosilicate glass, quartz glass, and the like. Since different glasses have different physical and chemical properties, different types of electric light sources should be made of different glass materials. Among them, soda lime glass is used as the glass bulb material of ordinary incandescent lamps, fluorescent lamps and low-power gas discharge lamps; lead glass is used as the core material of the lamp; the glass bulb of the high-power discharge lamp with higher working temperature needs boron Silicate glass; a single-ended tungsten halogen lamp requiring a higher operating temperature uses an aluminosilicate glass; and quartz glass is used as an arc tube material of a metal halide lamp having a large volume. There are two kinds of glass tubes for fluorescent lamps: one is a fluorescent glass tube. Different types of fluorescent glass tubes have different shapes. Among them, the glass tube of the straight tube type fluorescent lamp is relatively simple, and the soda lime glass material is often used; the glass tube of the circular fluorescent lamp and the compact fluorescent lamp is relatively complicated, so the processing performance of the glass is required to be good, and the lead glass material is often used. The second is the core column. The stem consists of a horn and an exhaust pipe. Because of the need for processing and molding, lead glass materials are used, and lead glass having different lead contents is selected depending on the degree of automation of the production line for manufacturing fluorescent lamps. In recent years, all countries in the world have attached great importance to the protection of the environment, and have introduced regulations to limit the content of heavy metals such as lead, and even do not allow lead. The lead content of lead glass for fluorescent lamps is also decreasing year by year, and lead-free glass tubes have also been developed and used for lamp making. Fluorescent lamps have developed rapidly in recent years due to their many advantages such as energy saving. In 1996, the output of fluorescent lamps in China was only 410 million, and the ratio with incandescent lamps was 1:8. By 2003, the output of fluorescent lamps in China increased to 1.85 billion, and the ratio with incandescent lamps rose to 1:2.2. Its variety structure is also developing towards energy saving: compact fluorescent lamps and energy-saving thin-tube fluorescent lamps are increasing year by year, while thick-tube fluorescent lamps are decreasing. The rapid development of fluorescent lamps has led to the development of glass tubes for fluorescent lamps. The sodium-calcium glass tubes and lead glass tubes used in the production of domestic fluorescent lamps are all supplied by domestic glass tube production plants. Synchronized with the development of fluorescent lamps, in 2003, China's fluorescent lamps used about 220,000 tons of various glass tubes, of which the output of soda-lime glass tubes exceeded 120,000 tons, about 650 million; the output of lead glass tubes exceeded 100,000 tons, which is used for compact fluorescent lamps. The low lead glass tube exceeds 50,000 tons. 1. Production technology of glass tubes The two glass tubes used in fluorescent lamps are produced in the same manner. The raw materials are firstly melted in a large pool furnace, and then formed by Danner method or Vello method, and then cut into the required length, and the cut port is rounded and tested. The packaging is shipped. The first fluorescent lamp in China was manufactured by Nanjing Huadong Electronic Tube Factory. At that time, fluorescent glass tubes were manually drawn. The worker holds a hollow high temperature resistant rod and picks out the molten glass frit from the glass furnace and fixes it on a fixture. Then, while receding, while blowing, pull into a glass tube. In the mid-1950s, following the Beijing Bulb Factory, China introduced a production line for automatic drawing of fluorescent glass tubes from Hungary, which changed the backward condition of artificial tubes. Since the 1980s, domestic companies have introduced more than ten automatic pipe production lines from Italy, the United Kingdom, the United States, Japan and other countries. For example, the Dana process line with an annual output of 1100-1600 million soda-lime glass tubes imported from Japan NEG and Toshiba; the 20-million-year-old Verofa production line imported from Corning, Inc.; GB company introduced the annual output of 2,000 tons of lead glass tube Danafa production line and so on. In the late 1980s and early 1990s, domestic companies purchased the technology of NEG in Japan and began to imitate the medium-speed automatic production line. After being used by many enterprises and improved many times, the domestically produced automatic drawing tube production line has gradually matured and has been widely adopted by domestic manufacturers. At present, most enterprises use domestic equipment, and a few are introducing equipment.
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