[edit]Definition of ultraviolet lamps
Ultraviolet that is Ultraviolet, referred to as UV, ultraviolet lamps referred to as UV lamps, which according to the different bands, respectively, UV-A, UV-B, UV-C each with different uses.
1, low-pressure UV lamps that germicidal lamps are mainly used for sterilization, in addition to UV-B is also mainly used for ultraviolet testing, medical treatment.
UV germicidal lamps 2, strong UV high-pressure UV lamps made of high-quality pure quartz tubing, so that the UV can be a high degree and a large number of penetration, its arc length / light-emitting length can be from 5 centimeters to 300 centimeters ranging from the common power of 30W to 200W per centimeter, ultra-high-power UV lamps are generally operated in the 200W per centimeter or more, the light spectrum of the effective range in the Between 350-450nm, the main wave peak of 365nm, there are more than 700 varieties, the power from 100w-25kw.
The life of the UV lamp generally refers to its ability to maintain sufficient energy for the operation of the time, during which the energy gradually declined until it is below the acceptable range until the general situation of the standard UV lamps can radiate sufficient UV energy up to 800 hours, the UV lamps imported from Korea by Tianjin Risentech, the UV lamps imported from Korea by Tianjin Risentech. The UV lamps imported from Korea by Tianjin Risentech can reach more than 1500 hours.
UV UV curing is widely used in bamboo and wood flooring, furniture, decorative materials, printing, printing iron canning, plastic coating, signage, circuit boards, CD-ROM and other industries; UV lamps are also semiconductors, electronic components, liquid crystals, such as bonding curing of the ideal light source.
[edit]Classification of UV lamps
Can be classified according to the energy per centimeter lamp (W/CM), commercial UV lamps are divided into 80, 100, 120, 150 and 240W/CM. UV output and curing speed is often not a linear relationship between. The relationship between the two depends on a variety of factors, such as the coating, substrate, reflector geometry, and the total efficiency number of the lamp. The sensitivity of the pigment material to heat, the pigment, and the thickness of the coating film all affect the effectiveness of the UV light source.
The UV band covers the range of 100-400NM, but since UV-curable coatings are generally active at 200-450NM, commercial UV-curable luminaires are designed around this range to produce high UV light intensity in this region.
Currently, commonly used UV curing light sources mainly include mercury vapor lamps, metal halide lamps, induction lamps and xenon lamps and other types. From the lamp structure, the lamps can be divided into two different types of UV lamp systems: electrode lamps (arc lamps) and electrode-free lamps (induction lamps).
1, mercury vapor pressure lamp
At present, the most commonly used UV light source is mercury vapor lamps, mercury vapor lamps can be divided into three types: low-pressure mercury lamps (10-100 Pa), medium-pressure mercury lamps (~ 100,000 Pa) and high-pressure mercury lamps (100,000 Pa). It should be noted that high, medium and low pressure mercury lamps are defined in accordance with international common standards and differ from the domestic designation. Early UV curing processes used low pressure to cure polyesters containing styrene. Due to the small output power of this lamp source, it was soon replaced by medium-pressure mercury lamps. Domestically, the above medium-pressure mercury lamps are generally referred to as high-pressure mercury lamps. The mercury vapor pressure lamp is a sealed transparent quartz tube of varying length (up to 120 meters) filled with mercury. The electrodes are generally made of tungsten, located at both ends, when the current is passed between the two poles will arc.
UV Solid-State Lamps (Mercury) All mercury vapor lamps used for UV polymerization reactions are made of quartz, even though quartz is more expensive. The main reason for this is that quartz has three important properties well suited for making UV lamps: (1) it is transparent to UV light and absorbs no or very little UV; (2) it is a poor conductor of heat; and (3) it has a low coefficient of thermal expansion, and the purity of the quartz and the presence of other trace compounds affects the emission characteristics of the lamp. The lamp is a fused quartz tube with a wall thickness of about 1MM and an outer diameter of 20~25MM, with a total arc lamp length of 2M, and a complex electrode layout (electron emitter, base, conductor, etc.) sealed at both ends of the quartz tube, which contains mercury for the emission of energy as well as a starting gas, usually argon.
When the luminaire is energized, an arc is created between the two electrodes. As the voltage between the electrodes increases, the temperature of the gas rises, causing the mercury to vaporize, producing a mercury vapor arc and emitting a characteristic ultraviolet light. When operated at full power, the lamp also emits visible light as well as some infrared (IR) light. Low Power Germicidal Lamps (for Consumer Products)
Arc lamps require several minutes of warm-up time (ranging from 2 to 10 minutes) to reach full spectral output, because the mercury must be completely vaporized inside the quartz tube. At the beginning of the warm-up period, more of the input power is consumed in preheating the electrode parts of the lamp, which eventually vaporizes all the mercury present in the tube. Therefore, the long induction period is one of the disadvantages of this lamp. In addition, if the power supply is suddenly interrupted during operation, the mercury condenses rapidly, making it difficult to restart immediately. The heavier thermal load also requires a cooling time. Usually a cooling period (15-20 MIN) is required after shutdown before the lamp can be restarted again. For this reason, arc lamps are fitted with mechanical or electronic photogates to prevent the high intensity IR from burning the medium, while also minimizing the heat and energy consumption of the lamp. Capillary Mercury Lamps (for PCB industry)
A chemical reaction occurs between the electrodes and the filler in the lamp, which gradually reduces the UV output over time. In addition, every time the lamp is switched on and off, the filler may be deposited on the quartz tube, shortening the life of the lamp. The average lamp life is 1000-1500 hours.
2, metal halide lamp
In order to change and adjust the output spectrum, to get more suitable for a particular purpose of the lamp, the lamp can be added to other materials. Metal halides such as aluminum, germanium, magnesium, thallium and other metal iodides are added to the mercury, the wavelength of the emission will be shifted in the direction of long wavelengths. For example, when magnesium iodide is used, the magnesium outputs spectral lines of 280 NM, 310 NM, and 385, which can increase the cure rate.
Metal Halide LampsTianjin Ruisent production of high-pressure mercury lamps filled with ferrous iodide, due to the filling of the lamp with different amounts of ferrous iodide, to get a more ideal spectral distribution, the iron spectral lines (358NM, 372NM, 37.37NM, 374.5NM, 382NM, etc.) to enhance the vitality of the ultraviolet region of the radiant energy, is the high-pressure mercury lamp energy output of 3-4 times. The energy output of the lamp is 3-4 times higher than that of a high-pressure mercury lamp. The lamp is based on the strong UV high-pressure mercury lamps to add metal halide to make it in the effective spectrum between 350nm-450nm radiation enhancement. Metal halide lamps are suitable for dry film, wet film, green solder resist exposure and UV ink curing, the lamp's most important feature is the high UV intensity.
3, xenon lamp
Xenon lamps were originally developed for photographic applications, but in recent years, people have shifted their attention to the field of UV curing applications. Xenon is a gas, so it can be used as a continuous light source, but also as a pulsed light source. As a continuous light source its xenon arc is essentially continuous, with a low UV output and a high infrared region. In pulsed xenon flash lamps, the UV output is increased due to higher gas pressure and higher temperature in the plasma zone. The temperature in the plasma region is proportional to the square root of the current density and lamp diameter.