What is spot UV printing ?
Modern books often use partial UV on their covers, and it has also been widely used in gifts, packaging bag, advertising, calendars, and plastic products.
It is not limited to flat surfaces, but also touches every corner of life. From the cover of creative books to the packaging of everyday items, every design incorporates a touch of art and technology through the addition of localized UV, enhancing the added value and user experience of the product. This is partial UV, the innovation and refinement in printing art, bringing endless surprises and possibilities to the visual world.
The benefit of Spot UV printing
UV printing has good printability for most substrates. UV printed products have clear dot patterns, good tone reproduction, bright and glossy ink colors, and high printing consistency. At the same time, because the UV curing process is a photochemical reaction process, both the ink layer and the varnish layer have the advantages of strong adhesion, durability, water resistance, chemical corrosion resistance, wear resistance, aging resistance, etc.
Drying is carried out through photopolymerization, which does not require a heat source, does not contain solvents, and has a very short curing time. General UV processes can achieve a line speed of 400 meters per minute, greatly improving production efficiency. After printing with UV ink, it is processed by a UV polishing machine to obtain printed products with high glossiness and a smooth, uniform and consistent surface. After the machine is connected for polishing, packaging processing techniques such as die-cutting, indentation, gluing, and hot stamping can be immediately completed, which is very beneficial for the development of high-speed printing. High speed means that it can reduce the storage costs and financial pressure of raw materials and finished products. At the same time, due to the low energy consumption of UV curing, the operating costs are greatly reduced.
The entire curing system of UV printing is a solvent-free system, which means a 100% solvent-free formula and does not contain VOCs, which precisely meets today's environmental requirements. This is another important feature of UV cured ink, as the solid content of UV ink after curing is close to 100%, almost free of VOCs (organic volatile compounds), which means that volatile organic compounds are not or rarely emitted during the curing process, causing no harmful environmental pollution. It also saves energy and does not have to worry about handling harmful flammable and explosive materials. It is an environmentally friendly ink.
The chemical substances in UV ink form a high molecular weight three-dimensional network polymer through cross-linking reaction. Therefore, using UV ink can make the ink layer of the printed product strong, fast drying, and cross-linked. Such ink layers have high abrasion resistance and chemical resistance. Many printed products printed on copperplate paper using UV ink for direct mailing can withstand multiple folds and strong radiation during laser printing, making UV ink suitable for outer packaging printing that requires wear resistance.
UV ink only dries under the irradiation of ultraviolet light. Even if the ink is stored in the ink hopper for a long time, its performance can remain stable and there will be no skin formation on the ink roller. Once exposed to ultraviolet radiation, the ink can be instantly dried, and generally only takes 1/10 of a second to completely dry and fix on the surface of the substrate. Traditional thermosetting ink and single sheet offset printing ink may take several minutes or even days to completely dry, so using UV curable ink to print movable parts has a short delivery time and can be comparable to flexographic and gravure printing, greatly improving the production efficiency of printing.
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