Printing ink knowledge

Photochromic ink

Photochromic inks, also called photochromic inks, are photochromic or photoactive compounds that are added to the ink. In the sun, the ink can change from colorless to colored, or from orange to black, etc., and can generally be divided into common type and UV type. . Ordinary type means that under the effect of ordinary daylight and strong light, the color of the ink will change, and it will return to its original shape after leaving the light source. It looks like it is discolored under the sun, and it is essentially changed by ultraviolet radiation. The color changing wavelength is 400~800nm. The application of this kind of ink in packaging and decoration not only can improve the grade of goods, increase interest, but also highlight the anti-counterfeiting effect. UV type ink is colorless or does not change color under the irradiation of ordinary light sources, but it will show bright red, orange, yellow, green and green fluorescence under UV light (UV light) irradiation. Most large denomination banknotes are printed using this kind of ink, and authenticity can be revealed under the effect of a counterfeit money detector.

In screen printing, thermochromic and photochromic inks can be transferred to different substrates, such as paper, cloth, nylon, plastic, metal, glass, ceramics, etc., by screen printing. It has the characteristics of sensitive to external conditions, obvious changes and rapid recovery. It is the ideal material for anti-counterfeiting technology and interesting gifts. It has broad development and application value.

5. Fluorescent ink

The fluorescent ink is made of a fluorescent material dissolved in the corresponding resin. Fluorescent pigments are generally coarser particles, and the types of binders are also more. Different binders will produce different fluorescence. When using fluorescent inks, it should be ensured that it has sufficient concentration, and the ink layer on the prints is a little thicker. Satisfactory fluorescence effect is guaranteed. Fluorescent inks are printed brightly after screen printing, and the decorating effect is very good. Under the action of visible light and ultraviolet rays, it can give off glittering fluorescence. Fluorescent ink can be self-aligned, different formulations can get different fluorescence effects, and its anti-counterfeiting effect is better. However, fluorescent inks have poor light resistance, and prints used outdoors are not effective.

6. Storage and Phosphorescent Inks

The light-storing pigments are prepared using certain zinc sulfide/copper phosphors, calcium sulfide/germanium phosphors, etc. having a phosphorescent effect in inorganic phosphors. Inorganic fluorescent substances are generated by crystals. If the crystals are broken due to pressurization, resulting in reduced luminosity, screen printing is generally suitable. Ink carriers and fluorescent substances are mixed during use. Phosphorescent inks are characterized by the ability to absorb light and emit light at a certain wavelength within a certain period of time. The pigment of this ink is a zinc sulfide containing a small amount of impurities (such as cadmium zinc sulfide), which is afraid of acid and alkali, and therefore requires neutral resins such as cyclohexanone resin, cellulose ester and ether. In addition, heavy metals, desiccants, and drying oils should not be added to the ink to avoid damaging the pigment material. The link material used requires transparency and UV light transmission. This type of ink is mainly used for printing advertisements, signage, etc. However, if phosphorescent inks and fluorescent inks are used in anti-counterfeit packaging printing, they can receive very good packaging decoration and anti-counterfeiting effects.

7. Printing ink

The printing ink is mainly composed of pigments, fillers, binders, etc. The choice of pigments is an important step in determining the hue and vividness of printed products. Many manufacturers and ink manufacturers have customized special inks for printing of each product. Its formula is kept confidential by the ink factory. For example, the “China” and “Peony” cigarettes produced by the Shanghai Cigarette Factory are printed with special inks that are specially customized at the Shanghai ink factory. This type of ink does not know that the detailed formula is difficult to tune, and therefore has a better anti-counterfeit effect.

8. Composite ink

After mixing two or more anti-counterfeit inks in a certain proportion, composite inks with new properties can be developed. If the ink formulations are not fully understood, it will be difficult to imitate them.

9. Other security screen printing ink

Plastic security ink. Applicable to PP, PVC, PE, PS, ABS, PC and other plastic products, with 150 ~ 200 mesh polyester net, each kilogram of ink can be printed 20 ~ 30m. , Dry naturally or at 130 °C for 3 minutes.

Metal, glass, ceramic security ink. Suitable for printing on metal temperature signs, color-changing glass ware, color changing milk cups and ceramic tea sets, etc., with 70 to 100 mesh polyester mesh, 10 to 20 square meters per kilogram of ink, and drying conditions of 25, 48, or 120 degrees Celsius. 45min.

Glass, ceramic decal transfer paper security special ink. Applicable to the printing of glass and ceramic decals, with a 150 to 200 mesh polyester web, and the drying conditions are 200°C and 20 minutes after water transfer.

Water-based security inks and printing pastes. Applicable to printing on paper, cotton, knitted fabrics, T-shirts, sportswear, etc., with 80 ~ 150 mesh polyester net, each kilogram of ink can be printed about 20m2 (cotton fabric will be less than this number), drying conditions for 130 °C, 3min.

Second, the overview of the flexible packaging market in Asia The trend of future flexographic printing in Asia When a country reaches a prosperous living standard, it will inevitably improve its packaging materials and its internal products. By that time, Asian supermarkets will become very influential. Printing and processing industry workers are also beginning to face new pressures. This is like a Western version. As the number of production becomes less and the printed materials have become more diverse, especially the use of PE films, these will stimulate new developments in flexographic printing.

At present, CI flexo printing machines for printing plastic films are closely related to the development of high-quality PE films. At present, many Asian packaging and printing industry believe that they do not need flexographic printing, because there is not a lot of PE film packaging, they have not yet encountered the need for short version, the pressure of rapid replacement of print jobs, and they like gravure Better than the interest in flexo printing. However, in the long run, investing in flexo printing is more worth considering than reinvestment in the future. Opportunity is to favor those who are ready for printing and processing.

Will Asia's packaging and printing industry use flexible printing to reach 60% or 80%? Our view is that flexo prints will appear in more supermarket shelves, but it will not necessarily reach the European proportion. The reason lies in the different modes of thinking, such as the preference for food. In the long run, this difference also lies in the fact that changes in consumption habits do not happen overnight.

We believe that the future of flexographic printing in the wide-format packaging industry will shine in Asia. The main reason is that Asian printers will acquire advanced high-quality CI machines from Europe and the United States, and will Establishing partnerships with printer manufacturers and consumers has enabled them to produce high-quality print products in a very short time.

The traditional thinking of buying machinery is about to disappear, and now buying a machine requires a complete analysis. The main determinants are no longer price, but cost recovery and profitability. Flexographic printing can be compared with gravure printing. Modern consumption habits and current sales channels have promoted the universality of TQM/JIT: while TQM/JIT has promoted the trend of a small number of orders, that is, everyone likes to adopt a printing method with a short print preparation time, and therefore likes flexographic printing to win. For gravure printing.

Another important reason is that the quality of flexographic printing is rapidly increasing, and there are many technologies that can make flexographic printing quality more effective, such as CTP (computer-to-plate), CTS (direct output sleeve plate-making), and the latest laser engraving. Produced more sharp ceramic anilox roller, uV, IR, EB ink and other coating glazing, printing plate FM screening technology.

We believe that the share of flexographic printing in Asia will increase significantly in 2005, Japan will reach a 7% share, and other Asian countries will reach 15%.

Third, as long as you go to the local supermarket and stroll around, you will find some very interesting phenomenon, what is the local people's buying habits? The total shelf space of a product and its sales is about what ratio?

When a country's economy develops to an affluent level, it will inevitably improve the packaging materials and their internal products. By that time, supermarkets will become very influential. Printing and processing industry will also start to face new pressures. This is also Western. Reprint.

Currently in Europe, about 60% of flexible packaging uses flexographic printing, and in North America it is as high as 80%. However, in Asia, flexo printing is only used in corrugated box printing, as well as some narrow-width packaging printing such as trademarks, labels, folding cartons, etc. High-quality wide-format flexographic printing machines (plastic film printers) only have about a dozen or so color flexible packaging; and high-quality intaglio printing machines have hundreds of units even if there are not thousands of them.

Differences between East and West Consumers Westerners are often surprised that they found that the demand for print quality in Asian consumers was so high that they even exceeded Western consumers. This should be the habit of Japan. Most of the general users in Asia know about flexographic printing. They still remain in the past understanding and impression. They believe that the quality of flexographic printing is too poor. Only the quality of gravure printing plastic film is known to be acceptable.

In recent years, the progress of flexographic printing has been amazing, and it has now reached the quality that Asian users want. Technological advances, such as thin-stencil technology, laser-engraved anilox rollers, elastic sleeves, and newly developed water-based inks, are key drivers of high-quality printing of flexographic printing, such as those that used offset or embossing in the past. Businesses such as trademarks, labels, folding cartons, etc., can now be changed to narrow or medium flexo printing.

Although most packaging consumers in Asia do not seem to be willing to adopt new trials, some multinational corporations in Asia have introduced their flexographic printings that have been matured in other parts of the world to Asia and have already processed packaging for Asian markets. Manufacturers provided a reference, and its guiding role has been to encourage Asian printing companies to invest in flexo printing.

In most western countries, the majority of foods are sold in supermarkets. Supermarkets are bound to become very powerful mentors in the packaging industry and teach them how to calculate their own costs. Most markets require a small but fast delivery (J1T) to meet the limited space on the shelf. The food industry's promotion methods are also frequently launched, which has accelerated the transformation of multi-pack design.

Printing and processing industry people like to apply the advantages of flexographic printing to cope with the market's rapid transformation and demand. The important thing is that flexo plate making is much faster than gravure plate making, and it is extremely cheap. Flexographic printing can quickly change substrates of any material. Even films like PE can be replaced immediately and can be produced at full speed (300 meters/inch). Minute). European printers use flexo printing of PE or PET to achieve the required high quality, rapid replacement and high-speed production.

In Asia, supermarkets can attract ordinary citizens, but housewives still like traditional markets. Supermarkets do not have the advantage of food suppliers, so the development of flexible printing has been slower.

Reprinted from: Design Momentum