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What Is The Magic Of Odorless LED-UV Ink? Printing Companies Are Rushing

Aug 20 , 2020

Due to the limitation of the spectral width of the semiconductor materials in the LED components, the ultraviolet light emitted by the LED-UV light source has an extremely narrow wavelength distribution, and a single wavelength has strong energy. Therefore, traditional UV inks cannot be cured under the LED-UV light source.

For this reason, odorless LED-UV inks with extremely high reactivity at specific wavelengths came into being. If the odorless LED-UV ink is to be fully cured under the LED-UV light source, the raw materials must be strictly screened during the development of the odorless LED-UV ink. The Odorless LED-UV Ink Manufacturer tells us that it is mainly due to the following two factors.

1. Photoinitiator

For ordinary UV inks cured under wide-band high-pressure mercury lamps and metal halide lamps, a wide range of photoinitiators can be selected, and combined photoinitiators have a good absorption response to ultraviolet light of different wavelengths, and LED- There are few photoinitiators that react with the ultraviolet light emitted by the UV light source, so it is necessary to select photoinitiators with excellent reaction performance.

The photoinitiator of the odorless LED-UV ink not only needs to have strong absorption of the narrow-band ultraviolet light emitted by the LED-UV light source, but also must achieve simultaneous curing on the surface and inside of the ink layer. Therefore, when choosing the photoinitiator for the odorless LED-UV ink, the photoinitiator should have the best absorption characteristics at the specific wavelength of the LED-UV light source, and the photoinitiator combination with the best ratio should be developed. , In order to absorb the limited ultraviolet light energy as much as possible. Especially for transparent varnishes, it is necessary to find a photoinitiator that can balance the yellowing property and curability of the varnish within a limited range of photoinitiators.

Odorless LED-UV Ink

Odorless LED-UV Ink

2. Pigment

Offset printing usually adopts the color sequence of "black→cyan→magenta→yellow" for overprinting. The black ink printed first can only be cured by the weakened ultraviolet light after passing through the cyan, magenta, and yellow inks. The pigment in the ink film easily absorbs ultraviolet light, so it is usually difficult for ultraviolet light to reach the inside of the ink layer, resulting in incomplete curing of the ink. For ordinary UV light sources, because the spectrum contains short-wave ultraviolet light, the deep curing of the ink layer is ideal; for LED-UV light sources, because it emits only long-wave ultraviolet light and a single wavelength, if the pigment in the ink If the absorption wavelength coincides with it, the curing performance of the ink will deteriorate.

Therefore, compared with ordinary UV inks, odorless LED-UV inks must use pigments that have the best penetration (least absorption) for the specific wavelength of the LED-UV light source used. This is one of the key factors in the development of odorless LED-UV inks. At the same time, using pigments with better coloring ability to increase the color density of the ink and reduce the amount of printing ink (so as not to affect the curing effect due to the thick ink layer) is also an effective means to improve the curing performance of the odorless LED-UV ink.

Through strict screening of the above-mentioned raw materials, even if the output power of the LED-UV light source is small, the odorless LED-UV ink can be fully cured.

In addition, it should be noted that since the odorless LED-UV ink can be cured by visible light with a relatively close wavelength range, strict filter treatment is required in the workshop during the production process. At the same time, when grinding and dispersing raw materials, it is necessary to strictly control the temperature of the workshop to prevent excessive temperature from affecting the ink performance.

Odorless LED UV Ink Supplier also said that LED-UV curing technology is green, environmentally friendly, and has broad development prospects. Although there are still some obstacles to its promotion, I believe that with the joint efforts of the industry, it is odorless LED-UV inks are bound to usher in a climax of development.