With good sterilization and disinfection capabilities, ultraviolet lamps have been widely used in daily life and industrial fields. At present, the common materials of ultraviolet lamp tubes on the market mainly include ordinary glass materials, high borax glass tube materials and quartz glass tube materials. Among the three materials, the performance of ultraviolet germicidal lamps made of quartz glass tubes is more outstanding.
At present, the lamp tubes of general ultraviolet disinfection lamps on the market are made of quartz glass. Quartz glass has a high transmittance to ultraviolet rays in various bands, and generally can reach 80%-90%. Although quartz is relatively expensive, all used Mercury vapor lamps for ultraviolet polymerization are all made of quartz, and the material of the lamp head is mostly bakelite, plastic or ceramics. It can be said that quartz glass tubes are the best material for ultraviolet disinfection lamps.
Compared with ordinary glass material, the ultraviolet transmittance is slightly lower, and the light attenuation is still greater than that of quartz germicidal lamps, and it cannot produce ozone. Compared with ordinary glass tubes, quartz glass tubes have obvious advantages in manufacturing ultraviolet germicidal lamps. First of all, the thermal expansion coefficient of quartz is low, and the purity of quartz and the presence of other trace compounds will affect the emission characteristics of the lamp; secondly, quartz is transparent to ultraviolet rays and does not absorb or seldom absorbs UV.
The quartz tube is known to contain mercury for the emitted energy and an initiating gas, usually argon. When the lamp is energized, an arc is generated between the two poles. As the voltage across the electrodes increases, the temperature of the gas rises, vaporizing the mercury, creating a mercury vapor arc and emitting characteristic ultraviolet light. When operating at full power, the lamp also emits visible light and some infrared light.
In terms of UV pass rate, high borax glass tube is lower than ordinary glass tube, basically less than 50%. However, due to the cost relationship or different uses, there are also high borax glass tubes with a UV transmittance of less than 50% instead of quartz glass. The ultraviolet light intensity of high boron lamps is easy to attenuate, and the ultraviolet intensity will drop to 50%-70% of the initial value after hundreds of hours of lighting. After the quartz lamp is lit for 2000-3000 hours, the ultraviolet intensity only reaches 80%-70% of the initial period of the ultraviolet weather resistance test chamber, and the degree of light decay is far less than that of the high boron lamp. The production process of high boron glass is the same as that of energy-saving lamps, so the cost is very low, but its performance is far inferior to that of ultraviolet germicidal lamps made of quartz glass tubes, and its sterilization effect is quite different.
To sum up, there are three main materials used to make ultraviolet lamps. In terms of effect, quartz glass is the best material, followed by ordinary glass material, and high borax glass tube has the worst effect but the lowest cost. Good UV transmittance and ultra-low thermal expansion coefficient determine that quartz glass is the best material for making UV germicidal lamps.