UV printing is a printing process that dries and cures inks by ultraviolet light, which requires the ink containing photosensitizer to be matched with UV curing lamps. The application of UV printing is one of the important processes in the printing industry.
1) Process introduction.
UV ink has covered offset printing, silk screen, inkjet, pad printing and other fields, the traditional printing industry generally refers to the UV is the printing effect process, that is, on a print you want to print the pattern you want to wrap a layer of varnish (there is bright, matte, inlaid crystals, glitter powder, etc.), mainly to increase the brightness and artistic effect of the product, protect the surface of the product, its high hardness, corrosion and friction resistance, not easy to scratch, etc., some laminating products are now changed to UV, It can meet the requirements of environmental protection, but UV products are not easy to bond, and some can only be solved by local UV or sanding.
UV is the abbreviation of ultraviolet ray, and the spectral range of industrial UV light source is 200nm-450nm, which is divided into the following bands
uv a：320-400nm
uv b：290-320nm
uv c：200-290nm
UV V: 390nm or more.
(2) Process application
The application of UV printing is one of the important contents of the printing industry.
There is no doubt that the deep processing of packaging products such as: hot stamping, lamination, embossing and a variety of glazing applications have been common, among which special effect glazing has become a trend. The rise of various glazing technologies is largely due to the development of technology and the configuration of printing presses. In the folding carton printing of cosmetics and cigarette packs, sheet-fed offset printing machines occupy an excellent advantage. For those special parts that are difficult to be offset printing, they can be achieved by silk screen printing or single gravure printing.
The multi-unit glazing unit has become the basic component of the sheet-fed offset printing machine, through which it can easily complete the glazing of special effects, and some special materials are often used in cosmetics packaging. Metal cardboard, composite cardboard and aluminum-sprayed paper, as well as varnished cardboard, are more and more widely used in the field of cosmetic packaging, showing a momentum of sustained and steady growth. New transparent composites are also already being used in plastic box packaging. Since these substrates cannot be printed by ordinary means, but must be achieved by UV technology, not only are more and more UV varnishes being used, but the use of UV printing inks is also becoming more common.
In line with this trend, UV printing will become the standard equipment in the future, and it will no longer be a matter of luck to complete printing jobs with stable quality as in the past. The powerful delivery curing system is only the basic configuration, and the intermediate unit curing is no longer a luxury equipment, these devices provide a broad application space for printing enterprises, which can fully meet the various special requirements of the cosmetics industry. UV printing process mainly refers to the use of special UV ink on the UV printing machine to achieve partial or overall UV printing effect, he is mainly suitable for the printing of non-absorbent materials, such as: gold cardboard, silver cardboard, pearlescent paper, transparent self-adhesive, plastic, PVC, PE, grating, etc.
Compared with traditional offset printing, UV printing has the characteristics of bright colors, special printing materials, novel products, broad market prospects, etc., and is suitable for high-end business card boutique packaging, advanced commercial albums, special desk calendars, special label printing and other product fields.
(3) Process introduction
The growth of UV printing is driven by its value-added printing attributes, which can highlight several advantages in the publishing printing, commercial printing, packaging printing and label market applications. The reason for this can be seen in the increasing demand from users:
Not only paper and cardboard can be used, but a wide variety of substrates can be used, including low-absorbent or non-absorbent materials (plastics, foils, metals, and heat-sensitive materials).
A very high-gloss effect, and sometimes a combined effect of scratch and scratch resistance.
Varnishing of a variety of special functional, tactile and special graphic surface treatments.
It has a high surface resistance (resistance to rubbing and scratching), especially for packaging and publication covers.
Speed up the completion of jobs, especially short runs, as UV printing can be done immediately in many cases.
The key business advantage of the UV process is the flexibility of the application, which allows for a wide range of product functions and special applications on a wide range of substrates and finishes. This provides a creative opportunity for print buyers to differentiate their products and add functionality to their products. UV printing can provide value-added services to existing customers and attract new business. In some cases, UV printing and varnishing reduce overall production costs compared to other processes;On the other hand, higher sales** of UV products increase ROI even in the context of higher UV production costs.
UV printing is a highly reliable process. UV inks can be considered environmentally friendly because they do not produce volatile organic components (VOCs) solvent volatilization problems, for example, in the United States, some traditional sheet-fed ink fractions are classified as volatile organic components (VOCs), which are controlled by law and are within the scope of restrictions In these areas, UV is usually classified as "the best available process". In the European Union, the fraction of ink used in sheet-fed printing is also not classified as a volatile organic component hazard.
4) Process characteristics.
The amount of UV printing ink used is comparable to that of the traditional four-color process: UV ink is less wasteful.
Widely disseminated European experience has shown that the average production output should be similar to the traditional approach with good practices (configuration of UV solid equipment, chemical properties of inks and varnishes, and correct handling techniques). The overall energy cost of UV production in Shanghai is similar to that of the same press configuration fitted with infrared and hot air drying. The test results show that the power consumption of UV luminaires is 30% lower than that of infrared hot air drying (calculated using German Energy**). UV luminaires require more energy to start than IR emitters that do not have to trigger start, and UV luminaires typically have a higher KW rate than IR emitters.