Fudan University: Developing high-efficiency UV LED light curing system

With only one-fifth of the energy consumption, you can achieve half the speed of fiber production – efficient by the optical fiber drawing tower developed by Zhang Shanduan, deputy director of the Institute of Electric Light Sources at Fudan University, and the team of the School of Information Science and Engineering. The UV LED light curing system has completed a technological innovation breakthrough. This UV LED light curing system will be unveiled at the 18th China International Industry Fair. Most of the photocurable inks are cured by the system in just a few seconds. Such innovative technologies with high power density and low energy consumption will enable the manufacturing of the optical fiber industry to leap forward.

Beyond tradition, one-fifth of the energy consumption is achieved by half the irradiance

The most prominent advantage of UV LED curing systems is their low energy consumption. Compared with the traditional microwave medium-pressure mercury lamp, the high-energy consumption of more than 6000 watts, the line source composed of ultraviolet LED only consumes 1200 watts, saving 80% energy consumption.

Microwave medium pressure mercury lamps are the curing devices commonly used in fiber drawing towers in the past. In the process of manufacturing an optical fiber, when the optical fiber is drawn into a filament, it is required to apply a protective ink material to the surface and cure it, which is to say that the coating changes from a liquid to a solid. Production in the printing, automotive, electronics, furniture and other industries is indispensable. UV curing is the most common rapid curing process, and UV-sensitive coatings can be cured by exposure to the appropriate light source.

However, the traditional medium light source of microwave medium pressure mercury lamp has many drawbacks, which not only consumes a lot of energy, but also generates a large amount of heat during the operation of the microwave magnetron, and the radiation efficiency is also low. According to the spectrum, the ultraviolet light used for the curing of the medium-pressure mercury lamp is only about 10%, the visible light is 20%, and the heat is 70%. Its curing efficiency is difficult to meet the growing production needs of the fiber industry, and it is contrary to the current concept of promoting economic and environmental protection.

For this reason, Zhang Shanduan developed a more efficient UV curing system using UV LED light source. In addition to reducing energy consumption, the traditional equipment has a life of only 6000 hours. This system extends the service life to 30,000 hours. After more than one year of continuous operation, there is almost no light decay, and the photoelectric parameters remain in the factory state. According to the spectrum, the UV LED is very concentrated in the 365 to 385 nm band for fiber ink curing, and is more advantageous for curing than the medium pressure mercury lamp. Zhang Shanduan said: "The new UV LED light curing system requires only one-fifth of the energy consumption of the traditional one, and can achieve twice the irradiance than the conventional one. The drawing speed is increased by half and the work is longer."

Leading the world in LED power density ranking first in the world

According to reports, this UV LED light curing system can not only completely replace the traditional microwave medium pressure mercury lamp, but also achieves technical breakthroughs and innovations in many aspects compared with the existing similar products.

The system consists of a fiber curing oven, a driving power supply and a cooling system. The fiber curing oven is the core of the technology, and the LED light source is the most critical part of the whole system. At the Industrial Fair three years ago, the UV LED curing system developed by Zhang Shanduan team made its debut. At that time, the UV LED light source could achieve a power density of 200 watts per square centimeter, which has reached the world's leading level. This year's UV LED curing system for fiber-optic draw towers has increased the maximum package power density to 700 watts per square centimeter, solidifying the world's number one technology position.

The industry's most common UV LED chips can only withstand a current density of 1 ampere per square millimeter. The specially designed LED chip by Zhang Shanduan can increase this tolerance to 4.5 amps per square millimeter, thanks to its innovative packaging. technology.

Another major technological innovation is the efficient UV refraction and reflection system. The optical system consists of well-designed lenses and reflectors that converge the ultraviolet light from the source to the cylindrical axis, enhance the radiance of the shaft, reduce optical losses, and increase the speed of wire drawing.

Helping the future of production is expected to drive more industry changes

At present, the system has declared 6 invention patents, and the outstanding technical performance has also produced significant economic and social benefits.

With the help of the system, maintaining the same system input power, the drawing speed of the fiber drawing tower can be increased by nearly 50%, reaching an astonishing speed of 3,000 meters per minute. Nowadays, only two drawing towers can get the output of the original three drawing towers, which saves investment and increases production while reducing energy consumption.

The data shows that after several small-scale use of the system, several international fiber optic giants have added a total output value of 1.84 billion yuan in the past three years, with a new profit of 300 million yuan, and saved 4.02 million kWh of electricity. Yuan, reducing carbon dioxide emissions by 0.4 million tons. Therefore, the UV LED light curing system of this fiber drawing tower is a major breakthrough for the manufacturing of the optical fiber industry, which will vigorously promote the innovation of light curing equipment. Zhang Shanduan is confident that the upgrade of domestic enterprise fiber curing oven technology will be realized within three years. In the future, the technology is expected to be applied to more areas related to light curing, such as printing, wood flooring, home, flooring and other industries. For light curing such as paint, wood, printing, etc., the technology can also boost energy savings to 90%.