On the development and characteristics of UV curab

2022-08-08
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Brief introduction: the development and characteristics of UV curable ink

in 1969, UV curable ink was first used in paperboard (carton) printing in the United States, which took the first step of practicality. Japan began to apply it in metal printing and label printing in 1971, two years later. After that, the rapid curing, solvent-free, powder free and other characteristics of UV ink have been brought into play. The advantages of UV ink in the printing site (improvement of working environment, short delivery period, reduction of inventory, space saving, etc.) have been recognized, and its use has expanded rapidly

1. Development of LED ink

in 1969, UV curing ink was first used in cardboard (carton) printing in the United States, marking the first step towards practicality. Japan began to apply it in metal printing and label printing in 1971, two years later. After that, the rapid curing, solvent-free, powder free and other characteristics of UV ink have been brought into play. The advantages of UV ink in the printing site (improvement of working environment, short delivery period, reduction of inventory, space saving, etc.) have been recognized, and its use has expanded rapidly

however, in the past, UV light sources used in the printing industry generally used high-pressure mercury lamps and metal halogen lamps, Due to the large-scale of lamps and power supply devices, "relevant national departments take the lead in formulating relevant standards, laws and regulations, which make users worry about the damage of printing machines and substrates caused by large power consumption and heat generation, as well as the generation of ozone during use. However, in recent years, a light-emitting diode (LED) capable of emitting ultraviolet light has been developed, which is matched with a special offset printing ink (fdled Series) that solidifies instantly under led ultraviolet light." It was developed by Toyo Ink Manufacturing Co., Ltd

this paper compares the differences between traditional lamp light source and LED light source from the environment of UV curing ink, and introduces the principle and characteristics of LED curing ink

2. Environmental coordination of UV inks

1) non VOCs inks

the so-called VOCs is the strategy of volatileorganiccompounds, that is, the general term of volatile organic compounds. VOCs diffused in the atmosphere has a stronger greenhouse effect than carbon dioxide, the material of global warming listed in the article. In addition, VOCs can react in the sun and become oxidants (the cause of photochemical smoke). Therefore, countries around the world, led by developed countries, have formulated strict regulations on their emissions around the world

general offset printing inks are divided into thermosetting rubber wheel inks and sheet fed offset printing inks, both of which contain petroleum solvents. Drying process of sheet fed offset printing ink: when the ink is transferred to the paper, the solvent separates from the paper and separates out the resin components. At the same time, the vegetable oil components in the ink react with oxygen in the air to form a hardened ink film. Drying process of rubber wheel ink: after printing, after heating, the solvent in the ink evaporates, and resin components are separated out, thereby forming an ink film

about VOCs emissions. Sheet fed offset printing ink has the advantage that it does not need to consume energy when drying, aiming at the common technical difficulties in the utilization of graphene based heavy-duty coatings. However, due to the need for a long drying time, strictly speaking, in this drying process, the VOCs components in the ink are either left on the substrate or gradually released to the atmosphere. The rotary offset printing ink releases VOCs components after heating, evaporation and drying. These VOCs gases are tested by constant speed loading, constant speed deformation and constant speed displacement in the drying oven, and then decomposed into water and carbon dioxide after treatment in the reburning chamber. Therefore, from the perspective of VOCs, there are countermeasures

on the other hand, UV curable inks activate the photopolymerization initiator through UV irradiation, which then promotes the combination of monomers and oligomers (low molecular components) contained in the ink through chemical reaction to form a hardened ink film. Since there is no solvent producing VOCs in UV ink, of course, VOCs will not be discharged into the atmosphere, so UV ink is an environment-friendly ink system

2) earth ring warming

carbon dioxide has just been mentioned. Here is an example from the perspective of its becoming one of the substances that cause earth ring warming. In the drying project of rubber wheel printing, carbon dioxide will be produced due to the combustion of gaseous fuel, especially as the cost of not letting VOCs in the ink be discharged into the atmosphere, it is necessary to use a device such as a reburning chamber to burn the volatile VOCs, and then carbon dioxide will be produced

uv curable inks do not contain solvents, so it is unnecessary to configure the above-mentioned hot air drying device. The energy efficiency ratio required for ink curing can be said to be more than 5 times that of rubber wheel printing. Therefore, the total amount of carbon dioxide generated when using UV inks is less. From the point of view of global warming, it can also be said to be a system beneficial to the environment

3) powder spraying

sheet fed offset printing in order to prevent the back from sticking dirty, corn flour and other materials are sprayed evenly on the printing sheet by powder spraying. The result of powder spraying leads to printing, but this is also a field where the manufacturer of hard thermal insulation materials has established a reputation or lost reputation. The dirt of brushes and printing materials also pollutes the surrounding environment of printing, causing trouble to field operators

uv printing does not need powder spraying because it is instant curing. From the perspective of working environment, UV ink is a better ink system than sheet fed offset oily ink

as mentioned above, UV ink printing system has the advantages of saving energy consumption, space and short curing time compared with the printing system using traditional sheet fed oily ink and rotary offset ink, and its use has expanded rapidly in recent years

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