UV technology will become the first choice for more and more label printing companies

UV technology will become the first choice for more and more label printing companies

The demand for UV printing is rising all over the world, especially in Europe, the United States and Latin America. According to equipment manufacturers in Europe, the annual growth rate of UV models will reach 7%, the annual growth rate of UV drying devices will be 10%, and the growth rate of UV inks and varnishes will be the fastest, reaching 14%. According to the largest growth rate in the United States According to the statistics of ink manufacturers, the consumption of UV inks and varnishes in the local market has increased by about 15% every year, which is almost 10 times the annual growth rate of ink consumables in the traditional offset printing market.

The application fields of UV technology are also expanding, such as label, plastic, multi-functional sheet-fed and tape printing, etc. Especially in the field of label printing, UV printing reflects an unprecedented growth trend, high-speed flexo printing labels, shrink sleeves UV technology is being used in packaging, thermoforming package special effect label printing and more. This article will focus on the great promotion of UV technology to label printing from four aspects: high-speed curing, low thermal effect, wide substrate, and high solid content.

1. High speed curing

It has only been less than 20 years since the flexographic printing process was introduced into China, and the time for domestic printing companies to use flexographic printing to print labels is relatively short. Even today in the 21st century, domestic label printing still mostly adopts letterpress printing, and the adoption of flexo printing is still in the preliminary stage. However, for developed countries such as Europe and the United States, their label printing market is very mature, and more than 90% of labels are printed in China using flexographic printing. Although the flexo printing process is still young in label printing, this kind of label flex The printing method has a strong stamina. According to industry statistics, the current Chinese label market is rapidly rising at a rate of about 30% every year. While the label market is expanding, it has also contributed to the rise of the label printing industry.

There are two main reasons why flexo printing has become the mainstream process of label printing: First, as a relatively environmentally friendly printing method, flexographic printing is non-toxic and tasteless, and meets international environmental protection requirements. At present, many large multinational companies are increasingly strict on product packaging, and basically have used flexo printing to print product packaging. Domestically, pharmaceutical and food companies have become the main source of customers for label flexo printing in my country; second, flexo printing has more advantages in label printing than other printing methods, such as higher color saturation, which is very suitable for label printing. Standardization, outstanding spot color performance, easier to achieve combined printing, etc.

However, the printing speed of flexographic printing machines can usually be maintained above 100m/min, which is 2-3 times that of the most commonly used letterpress printing machines in label printing in my country. In such a high-speed printing environment, the efficiency of UV curing becomes The key to the success or failure of printing. The ordinary infrared drying process is far from meeting the requirements. The huge baking equipment and the lengthy baking tunnel are the nightmare of printing enterprises. Using UV drying and curing process, the ink can be cured within a few seconds after printing, which significantly improves the production efficiency, and can also omit the baking and drying process, and the drying equipment is simple and space-saving, which is completely suitable for the production of high-speed flexo labels.

2. Low thermal effect

Heat shrinkable film label is a film label printed on plastic film or plastic tube with special ink. During the labeling process, when heated (about 70°C), the shrinkable label will quickly follow the outer contour of the container. Shrinkable, close to the surface of the container, heat shrinkable film labels mainly include shrink sleeve labels and shrink wrap labels. The shrink sleeve label is a cylindrical label made of heat-shrinkable film as the base material after printing. It has the characteristics of convenient use and is very suitable for special-shaped containers.

The heat shrinkable film label is a part of the label market, which is currently in rapid growth, and its market share is expanding. It has become a bright spot in the label printing industry. It is predicted that the domestic heat shrinkable film market will grow at a rate of more than 20% in the next five years.

The production of heat shrinkable film labels has high technical requirements, especially when printing heat shrinkable films, how to control the drying temperature is very important. For ordinary water-based and solvent-based inks, the drying temperature is too high If the temperature is too low, the ink will not dry completely, resulting in problems such as sticking and dirtying on the back. Therefore, the process is quite complicated and the rejection rate is high. For UV curing drying technology, under the action of ultraviolet energy, the ink makes the polymer substance form a network crosslink in an instant, and the ink solidifies rapidly, which has no effect on the temperature of the printing material. The unique cold curing system is very suitable for heat-sensitive material labels. Production.

Recently, Mimaki has released the desktop UVLED inkjet printer-UJF-3042. This product completely uses UVLED to dry the printing ink. Pure UV drying hardly generates any heat, and it is even suitable for printing on thermal media such as acrylic plastics.

3 Wide range of substrates

In recent years, the total amount of cultural paper printing in the world has been declining, but label packaging printing is still growing, and label supplies are ubiquitous in life. With the wide application of labels, more and more printing materials such as polyethylene (PE) are used. Film, polyvinyl chloride (PVC) film, polypropylene (PP) film, metal foil and non-absorbent special materials, etc. The surface of these materials is dense and does not absorb ink. If ordinary solvent-based ink is used for printing, a certain drying time is required, and powder spraying, drying rack device or other additives are usually added to the ink, and UV ink is completely No such trouble. For example, Agfa's Abona UV inkjet printer claims that, in addition to air and water, as long as the material to be printed can be put into the UV inkjet printer, it can be directly printed. Applicable printed materials such as: paper, film, PE, PET, PP, OPP, BOPP, PVC, acrylic glass, wood, ceramic tile, etc.

4 High solid content

The solid content of the general solvent-based ink is about 40%, while the solid content of the UV ink after curing is close to that of the general ink, which is 100% of that of the general ink. The printing ink layer is thick and colorful, which is very suitable for label printing. Thickness can also achieve grating effect, relief effect.

The latest domestic UV three-dimensional grating ink UV-1278N is used to print the three-dimensional grating film by using the high solid content of the ink. The ink is colorless and transparent, quickly cured by ultraviolet light, the cured film is not yellowed, and the adhesion fastness is good. , good toughness. Different from the traditional hot-pressing process for preparing the three-dimensional grating, the new process adopts the screen printing method to print the ink on the transparent film of the packaging machine to directly form the columnar grating pattern; the three-dimensional grating ink can also be directly printed. On the printed matter, a three-dimensional pattern is formed, and the pattern can be selectively printed to make the part three-dimensional. The three-dimensional effect of the printed pattern is obvious, which is comparable to that of a hot-pressed grating plate, which opens up a new method for three-dimensional printing. Using the ink to print the lenticular film can greatly reduce the production cost and improve the production efficiency. The printing substrate can be a transparent plastic film, such as PVC, PC, PET, or paper, metal, glass, ceramics, etc.

The VersaUVLED launched by Roland is the world's first UV inkjet printer using safe low-heat LED lamps. It can not only print yellow, blue, black and white, and 5 colors and varnishes, but also has outstanding printing quality. The machine is mainly suitable for one-off packaging printing and short-run label printing, and can perfectly show "very rich special effects", whether it is high-gloss effect or texture effect, and can even reproduce artificial leather and crocodile leather. difference in texture.

In addition, UV technology is also favored in the printing of self-adhesive labels. At present, UV glazing technology has been widely used in the label industry to replace surface lamination. The glazing of self-adhesive labels is carried out on a rotary labeling machine. That is, a layer of UV varnish is evenly coated on the surface of the graphic immediately after printing. For flexographic prints using water-based inks, the glazing process is an indispensable process. Compared with traditional drying equipment, on equipment without UV drying, ordinary inks need to be stamped first and then printed. The disadvantage is that printing Pattern design is restricted. On the equipment with UV drying device, it can be printed first and then hot stamped, and the ink is quickly dried and then hot stamped on the ink.

5 Summary

In short, UV technology does not require a heat source, is pure ultraviolet cold curing, and is suitable for the production of heat-sensitive labels; and can cure quickly (curing time can be less than 1 second), high productivity and high process output can reduce the storage of raw materials and finished products ; The whole curing system of UV technology is a solvent-free system, 100% solvent-free formula, suitable for the production of special effects labels, and no VOC volatile organic substances, fully adapting to the requirements of environmental pollution regulations. It is believed that in the near future, technology will become the first choice for more and more label manufacturers.

https://www.minongpackaging.com/adhesive-sticker/self-adhesive-postage-labels.html