UV LED system for ink drying in packaging printing industry
The system, researched and manufactured by a team of authors from Ho Chi Minh City University of Technology and Education, can dry ink on non-absorbent printing materials, with a cost of only 1/5 of similar imported products.
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Fully assembled UV LED chip on aluminum block. Photo: NNC
In the printing industry, the drying stage of printing ink is quite important, helping to increase quality and productivity. Film, plastic, metal are materials that do not absorb ink, must use chemical drying method, to help the ink curing process fastest.
Currently, most printing factories use self-drying ink, which takes about 5-6 hours to dry. This slows order fulfillment time by waiting for the ink to dry completely. Sometimes, some orders need a fast delivery time, but the business cannot respond in time. The method used to dry the ink faster is to use ultraviolet light (UV LED lamp), due to many advantages, such as saving electricity, lamp life and high safety, and etc.
However, only a few large enterprises have invested in ink drying systems using UV LED lamps. The cost of the UV LED system to dry imported ink is up to several hundred thousand USD.
Stemming from practical requirements, the author group of Ho Chi Minh City University of Technology and Education has carried out the project "Research, design and manufacture UV LED system to dry printing ink in packaging printing industry."
After 18 months of research, the authors have built a UV LED drying system for printing ink, used for offset printers 52x72cm, with specifications, such as 396nm wavelength, 18W optical power, drying speed reach 7,300 sheets/hour, maximum drying area 720mm (72cm).
In particular, the drying lamp assembly uses UV LED chips (Japan) including 286 LED chips, designed with 3 rows and 4 columns to facilitate maintenance. This UV LED system can dry the ink on non-absorbent printing materials, such as plastic, PVC decal, metalized film. At the same time, the team also manufactured a cooling system for the lamp and synchronous control assembly. With printer, can measure, control UV radiation energy, measure, warn current through LED chip, monitor, warn error on HMI screen. The UV LED system can be controlled manually by manipulating the HMI screen or automatically following the printer's signal. In addition, the UV radiant energy is measured by the sensor and the power supply output current is also measured to control the radiated energy of the UV LED assembly. This helps to avoid errors that affect printed product quality.
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The UV LED lamp cluster is equipped and operated on a 5-color offset printing machine at Truc My Company. Photo: NNC
The UV LED system tested at a 5-color offset printing machine of Truc My Printing Company (HCMC) shows that it can meet the drying speed from 6,400 -7,200 sheets/hour, for non-absorbent materials, such as plastic, metalized, decal. The quality of printed products meets the requirements of dryness and can be transferred to the finished product stage right after printing, helping businesses to deliver goods quickly.
The research project of the group of authors has been accepted by the Department of Science and Technology of Ho Chi Minh City. With the price of about 1 billion VND (equivalent to 1/5 of the price of similar products in the US), the research results can transfer technology and commercialize the product.
ctngoc