The most popular ink anti-counterfeiting technolog

Ink anti-counterfeiting technology in ticket printing (Part I)

tickets cover a wide range, and to a certain extent, they all have the nature and function of money. In order to prevent the order of economic activities from being destroyed, anti-counterfeiting measures should be taken when printing these securities, so that people can easily distinguish their authenticity when using them, and outlaws cannot forge them

ticket printing is a special industrial department in the printing industry. The products produced are mainly special commodities in social circulation - banknotes, stamps, various bonds, promissory notes, cheques and various commercial bills

under the condition of market economy, the quality of ticket printing and the popularity of ticket use represent the level of market economic development. Generally speaking, all kinds of ticket printing are divided into valuable tickets and general tickets according to their different purposes; According to the different application fields and forms, it is divided into bank tickets, postal tickets, business forms, and electromagnetic tickets

the development of economy and technology has put forward high requirements for the anti-counterfeiting of tickets, and the anti-counterfeiting technology is also relatively complex: there are design, paper, ink and printing technology. In the anti-counterfeiting technology of ticket printing, if you want to reduce the cost of anti-counterfeiting technology and make full use of the current printing process, you generally consider starting with ink anti-counterfeiting. In addition to the normal expression of the corresponding hue, various anti-counterfeiting inks also have special changes under the action of external light, heat, reagents or magnetic fields, which the public takes as a means of identification

the application of ink technology to anti-counterfeiting is achieved by changing the formula of ink or adding some special sensitive materials, such as photosensitive materials, thermal materials, magnetic materials, etc. Ink anti-counterfeiting technology is currently the most rapidly developing high-tech. Because the main step of developing this kind of test mold ink is difficult, the import price is high, and it is difficult to buy in the market, which enhances the objective safety of using this kind of ink. Anti counterfeiting ink is the same as ordinary ink in terms of use. It is suitable for all kinds of printing machines, so it has good versatility. The following introduces several kinds of anti-counterfeiting inks currently used

I. magnetic ink

magnetic ink printing belongs to the category of magnetic recording technology. The magnetic recording body is made by printing, so that it has the required special properties. At present, magnetic inks are used in many fields, such as banknotes, invoices, cheques, etc. This kind of ink has been used on the 100 yuan banknote of the 1990 edition in China. Under the detection of special tools, this ink can display the information contained in it or send out information to show its authenticity

1. Most of the countries along the line of magnetic ink are underdeveloped countries. The basic composition of magnetic ink is the same as that of general ink, that is, it is composed of pigments, binders, fillers and additives. But the pigment used in magnetic ink is not pigment, but strong magnetic material. Magnetic materials have the ability to retain magnetism after magnetic field treatment. Of course, there are many factors that affect magnetism, such as the magnetism of pigments, the content of magnetic pigments in ink, the thickness of ink film after printing, etc

the main component of magnetic ink is magnetic pigment, and the best magnetic pigments are iron oxide black (Fe3O4) and iron oxide brown (fe2o310 learned from the Ministry of industry and information technology on 19). Most of these pigments are less than 1 μ M needle crystals, they are easy to be evenly arranged in the magnetic field, so as to obtain relatively high residual magnetism: the disadvantage is that the oil absorption is relatively large, and the transmission performance is not very satisfactory. Therefore, sometimes some granular or cubic iron oxides are used to improve its printing performance, but the amount should not be too much

the key to obtain excellent magnetic printing materials is to understand the basic characteristics of strong magnetic materials, reasonably select strong magnetic materials, and correctly determine the formula of magnetic ink. Iron oxide black pigment has high oil absorption and poor stability, especially the stability of dry pigment powder, so it has high magnetism. CrO2 is a black ferromagnetic oxide with very good conductivity. It is a promising magnetic material with mature and strong skills. (to be continued)