Introduction to the main varieties and performance of anti-counterfeit products 1. Invisible colorless fluorescent security ink This is a kind of anti-counterfeiting ink with mature technology and convenient use. Normally, it is white or colorless, printed on paper or plastic film with inconspicuous colors, and different colors will show different colors under the detector or ultraviolet light. It is applicable to the anti-counterfeit packaging of official brands, marketable securities, certificates, and all kinds of high-grade cigarettes, wines, medicines, and cosmetics.
Second, colored fluorescent security ink This anti-counterfeit ink in the detector or ultraviolet light can display the same color as the original ink, mainly used for bills or other anti-counterfeiting requirements of the print, there are different colors available to the user select.
Third, thermal color ink, also known as thermal ink, temperature change ink or temperature ink. This type of ink is divided into three categories: at room temperature, the specific color is displayed, and after heating, the color fades or becomes another color, and immediately after cooling, it returns to its original color or displays white; The color displayed after the temperature does not disappear after cooling, because the color change process is irreversible, is called "irreversible thermal color (hair color) ink"; the third type is called "reversible thermal transfer ink" †That is, the ink changes from one color to another color after warming up and returns to its original color after cooling.
The use of anti-counterfeit products and technical requirements First, the use of invisible colorless fluorescent anti-counterfeit ink colorless fluorescent ink is the same as the use of similar ordinary ink. It is used directly under normal circumstances. The user may also add some solvents or additives according to actual needs, such as:
1. Offset printing: mineral oil, varnish, coarse wax, desiccant, slow drying agent, etc. 2. Screen printing: 783 thinner, anti-blocking agent, defoamer, cyclohexanone, etc. 3. Gravure printing: Diluent Dry, neutral, quick-drying, users can self-distribution:
A. Slow drying: xylene, butyl acetate, cyclohexanone weight ratio 1:1:1
B. Neutral: Toluene (or xylene), butyl acetate, butanone weight ratio 1:1:1
C. Fast drying: weight ratio of toluene, butyl acetate, acetone 1:1:1
Colorless fluorescent inks can be mixed with similar four-color inks to form a variety of colored fluorescent inks, but the light color and brightness will be changed due to the difference in the color and the amount of added inks. Inadequate deployment will also affect the ink properties. The user should Under the guidance of the ink manufacturer, be prepared, or use a special spot color ink.
Users should pay attention to the following points when using offset or gravure colorless fluorescent inks:
1. The need to clean the transfer roller and printing plate, the use of a new ink roller is more ideal, otherwise, a very small amount of colored ink may also bring colorless fluorescent ink with color, affect the quality of printed products.
2. Different papers have different effects on the colorless fluorescent color. Since most paper surfaces are subjected to fluorescent whitening agent whitening, fluorescent whitening agents emit blue-white light under ultraviolet light, so there are no brightener papers (security paper, etc.) and papers containing brighteners ( On plain paper, there are certain differences in the color rendering effect of colorless fluorescent inks. It is worth mentioning that for this reason, colorless fluorescent blue inks are not very suitable for papers containing strong optical brighteners. Otherwise, the blue fluorescence will "flood" in the blue of the brightener.
3. This type of ink can be printed on the non-patterned part of the print or it can be printed on the pattern. To highlight the fluorescent effect, it is usually printed on the outermost layer of the pattern.
Second, thermal color ink This kind of ink due to the temperature change of the temperature of the material is relatively low, it is best used for ink thicker screen printing and gravure printing, and screen printing is better than gravure printing. Users must follow these precautions:
1. The number of screen meshes used for screen printing can be used up to 500 mesh (below 300 mesh, the printing effect will be better). In gravure printing, the pattern must be particularly deepened; the solvent used for gravure printing is cyclohexanone, xylene, etc.
2. Screen users can add some 783 thinner, anti-blocking agent and so on according to the mesh size and the ambient temperature. For gravure printing, solvents such as xylene and butyl acetate can be added, but alcohols and acetone solvents cannot be added to prevent damage to the microcapsules.
3. The color temperature turns red → ↠black and the temperature turns yellow → ↠red. Because they react with the iron, these two inks cannot be stored in the iron container. After printing, the remaining ink should be removed from the printer in time.
4. Temperature change black and temperature change blue can be used to cover other colors. For example, first use a regular ink to print a pattern or text, and then use a temperature change black or blue printed on top to cover it. When heated, the top color disappears to show the bottom pattern or text; after cooling, it is covered again. (Shanghai Wanqi Printing Technology Co., Ltd.)