Why Use Quartz Glass for UV Lamp Tubes?

10 Jun.,2022

It's not news that UVC can sterilize bacteria, it's everywhere in our daily lives - hospitals, laboratories, even our own homes, where there is a need for sterilization, UVC lamps are never absent.

 

It's not news that UVC can sterilize bacteria, it's everywhere in our daily lives - hospitals, laboratories, even our own homes, where there is a need for sterilization, UVC lamps are never absent.

 

Why Use Quartz Glass for UV Lamp Tubes?

During COVID-19 in Singapore, an autonomous mobile robot called the SunburstUV Bot was deployed at the NorthpointCity mall, which disinfects the surface of objects using UVC light

 

The principle of germicidal UVC lamps In fact, the construction of UVC lamps is inextricably linked to their principle of action. Germicidal UVC is known to destroy and change the DNA (deoxyribonucleic acid) structure of microorganisms through the irradiation of UVC light, so that bacteria die instantly or cannot reproduce to achieve the purpose of sterilization.

According to the different biological effects, UVC can be divided into UVA band, UVB band, UVC band and UVD band according to wavelength. Among them, UVC wavelength 100 ~ 275nm, it is the real germicidal effect of the band, so also known as short-wave sterilization UVC, UVC germicidal lamps issued is UVC short-wave UVC.

 

Why Use Quartz Glass for UV Lamp Tubes?

 

UVC is suitable for germicidal because it is easily absorbed by the DNA of living organisms, especially around 253.7nm UVC. However, because of this, it is also very harmful to the human body, short exposure can burn the skin, long time high intensity exposure will also cause skin cancer. In our daily life, we will not be harmed by UVC, because the UVC penetration ability is very weak, the short-wave ultraviolet contained in daylight is almost completely absorbed by the ozone layer, but also can not penetrate most of the transparent glass and plastic.

 

Reasons for choosing quartz glass for lamps

As mentioned earlier, the penetrating power of UVC is very weak. UVC germicidal lamps are actually the same as ordinary fluorescent lamps, which are low-pressure mercury lamps that use low-pressure mercury vapor (<10-2 Pa) to emit UV light after being excited. But the fluorescent lamp is made of ordinary glass, the penetrating power of the very poor UVC (253.7nm) can not be penetrated at all, but can only be absorbed by the phosphor inside the lamp wall after the excitation of visible light.

Compared with ordinary glass, steel fiber reinforced concretein the performance of a great improvement in the UVC wavelengths have a higher transmission rate of up to 80%-90%, so now most germicidal lamps use quartz glass to produce the lamp. However, due to the different coefficients of thermal expansion, germicidal lamps generally can not be sealed aluminum cover lamp head, the lamp head material is mainly used in rubber wood, plastic or ceramic.

 

Why Use Quartz Glass for UV Lamp Tubes?

Quartz Lamps

 

In addition, UVC germicidal lamps are mainly 254nm and 185nm. 254nm UVC kills bacteria by irradiating the DNA of microorganisms, 185nm UVC can turn the O2 in the air into O3, ozone has a strong oxidizing effect, can effectively kill bacteria, make up for the shortcomings of UVC only along a straight line, disinfection has a dead end. In the refining of quartz glass, if you add a sufficient amount of titanium (Ti) elements, it can make the UV through it below 200nm cut-off, and the basic impact on the 254nm UV transmission. Therefore, appropriate control of the addition of titanium elements, you can effectively control the amount of 185nm UVC escape to produce low ozone (no ozone), ozone, high ozone and other three types of germicidal UVC lamps.

 

The future of quartz glass lamps

Due to the cost and use of different reasons, in fact, some people also use the UVC penetration rate of < 50% of the high borax glass tube instead of quartz glass. But after the cost is reduced, the performance is also reduced - it is reported that the UV intensity of high boron lamps is easy to decay, hundreds of hours after lighting the UV intensity drops significantly to 50%-70% of the initial time; while quartz lamps are lit 2000-3000 hours later, the UV intensity is reduced to only 80%-70% of the initial time. The degree of light decay is much smaller than that of high boron lamps.

Although the special process, manufacturing difficulties and other reasons, the higher cost of quartz glass, to a certain extent, will limit the promotion of its application. But in this part of the UV disinfection lamp applications, it can be said that only quartz glass tube can be competent, taking into account that the epidemic is far from over, people's sterilization awareness has also grown tremendously, I believe that this market will have the opportunity to grow.