New anti-counterfeiting high-value-added laser pattern imprint transfer line

With the development of society and improvement of living standards, people are increasingly demanding the packaging of various articles, especially cigarettes, wine, food, medicine, cosmetics and other printing and packaging, in the direction of beautifying the appearance, anti-counterfeiting, and adapting to environmental protection. . To cater to the development trend of the market, Shantou Jinlan Packing Machinery Factory has painstakingly researched and tested repeatedly, and developed a new type of environmental protection and anti-counterfeiting printing equipment for the laser pattern imprint transfer production line. The production line aims at the insufficiency of the original laser pattern used on the packaging and adopts a more advanced technology to achieve the effect of beautifying the appearance of the printed matter and protecting the environment.

I. The lack of original laser anti-counterfeiting patterns on the packaging

The original common way to set up a laser anti-counterfeiting pattern on the packaging is: laser marking, composite laser film, and laser pattern positioning stamping.
The first method is to make laser anti-counterfeiting designs into self-adhesive labels, which are attached to the appearance of packaged goods and are commonly found on book covers or on the packaging of medicines and cosmetics. This method is relatively simple, but the laser icon can not be integrated with the box, can not beautify the appearance of the package, while the icon is easy to fall off, the production process is simple, thus affecting the effectiveness of anti-counterfeiting.

The second method is to compound the ordinary laser film directly on the paper. This method can make the laser pattern and the paper tightly combined, but the process is simple and can be completed by laminating machine, so imitation is easy and does not meet the environmental protection. And this method can only be applied to the entire layout, it is difficult to use on the local pattern.

The third method is to transfer the laser pattern to the printed matter by using a positioning stamping method. This process can be seen on some high-end cigarette packs. Using this technology, laser patterns can be printed on the packaging, the patterns are exquisite, the grade of the packaging is improved, and the anti-counterfeiting effect is also good. However, the cost of adopting this kind of technology is relatively high, and the price of laser bronzing film and positioning bronzing equipment is relatively high. Moreover, the process is more suitable for the local pattern of gold foil, if you want to make a larger laser pattern, and even the full version of the laser pattern is difficult to achieve.

II. Advancement in Laser Pattern Imprint Transfer Production Line Process

For the deficiencies of the above several processes, the laser pattern imprint transfer line adopts a more advanced process method. The process method breaks the conventional practice of directly laminating the laser film on the printed matter. Instead, it adopts an imprint transfer method and can exhibit the same pattern as the laser film on the product, and the effect is better than the direct composite laser film. The transparent laser pattern printed on the print can set off the original color pattern of the printed material, showing glitter and bright, dazzling effects. The advanced nature of this process is mainly reflected in the following points:

1. Meet the requirements of environmental protection. Because there is no composite plastic film on the package, the discarded package can be degraded in the natural environment. As the white pollution in the world is becoming more and more serious, the issue of environmental protection has received more and more attention. Many countries are taking measures to limit the use of non-degradable plastic products. At the same time, the solvent-based laminating process has solvent residues on the packaging of foods, medicines and beverages, which may cause pollution to people and food, medicines, and drinks, etc. The relevant state departments have stipulated that the solvent-based laminating film production process. With this process, the above problems can be avoided.

2. Anti-counterfeiting effect is high. Since the imprint transfer technology is novel, the patterns on the laser film can be customized according to their own requirements, so that the general counterfeiters cannot imitate.

3 can be a partial or comprehensive laser pattern printing. According to the need, different sizes and shapes of laser patterns can be designed on the packaging paper to achieve anti-counterfeiting and at the same time, the appearance of the package can be beautified, and the grade of packaging can be improved.

4. Effectively reduce printing costs. With this process, the laser film can be repeatedly used. If the operation is skillful, the laser film can be reused more than ten times, thereby greatly reducing the cost of the printed product.

III. Technical difficulties and solutions

At present, the process is mostly used for the packaging and printing of high-end products, such as cigarette packs, wine boxes, and medicine boxes. Because these prints generally have high requirements for printing quality, and because of the characteristics of the process itself, there are technical difficulties in the production line.

1. Since the local laser pattern is generally applied to the original printing pattern as a set off effect, the printed laser pattern must be strictly registered with the original printed pattern. In order to control the accuracy of overprinting, the oiling part adopts a flexographic printing press and a cheek bite paper structure, which can control the error of registration to within ±0.1 mm.

2. The thickness of the oil must be controlled. If the oil is too little, there will be partial lack of oil, and it cannot print a complete laser pattern. If the oil is too thick, it causes waste on the one hand, and on the other hand excess oil will flow under pressure during the imprinting process, affecting the registration. According to different papers, choose the right amount of oil.

3. The curing temperature after brushing must be strictly controlled within a suitable range. If the temperature is too high, it will cause deformation of the paper and the laser film, which will affect the effect of the imprinted laser pattern. In order to control the temperature of the UV lamp, domestic counterparts mostly use air-cooled or water-cooled. The effect of air cooling is general and can only be used in applications where the temperature is not high. Water cooling can effectively control the surface temperature of the printed product, but it greatly reduces the effective power of the lamp (the utilization of the lamp is only about one-third). In order to overcome the above shortcomings, the production line adopts a UV lamp shade cooling system with independent intellectual property rights. The cooling system adopts a cooling air cooling method, which greatly improves the utilization of UV lamp tubes. Therefore, using two UV lamps with a power density of 56 W/cm, the printing speed can reach 5000 sheets per hour. If water cooling is used, the power density of the UV lamp must reach 160W/cm. At the same time the system uses thermocouples, temperature control module, through the PLC to control the surface temperature of the printed product to maintain a constant. The surface temperature of the print must be controlled within the appropriate range when imprinting. Different printing speeds, full or partial pattern printing, different UV oils and other factors determine the difference in temperature. After determining the optimum temperature during production, the temperature should be kept constant and the temperature range should not exceed ±2oC.

4. The pressure adjustment of the imprinting process must be appropriate and uniform. Embossing pressure can be adjusted according to the thickness of different paper to make appropriate adjustments. The pressure must be uniform to make the printed pattern clear and consistent. The entire contact surface must be evenly contacted. If a certain point is not well pressed, no pattern will be printed or small bubbles will appear on the printed pattern, which will affect the effect of imprinting. At the same time, the hardness of the embossing roller is also critical. If the hardness is not suitable, "pinholes" will appear on the printed pattern.

5. In order to ensure that the laser film can be used repeatedly, it must be ensured that the laser film must maintain proper tension during operation. Excessive tension will cause the film to stretch and deform. Too little tension will make the film roll loose. In order to solve this problem, a tension automatic control system was adopted. During the operation, it must also ensure that the laser film is aligned in the edge during operation and cannot be deflected. The film feeding device adopts a correcting device to effectively control the alignment of the film edge line.

IV. Summary

Laser pattern imprint transfer production line has advanced technology and advanced technology. Because of its environmental protection and anti-counterfeiting technology, the safety has reached the requirements of international environmental protection and anti-counterfeiting products. At the same time, it can beautify the appearance and increase the added value of packaging products, thus causing concern in the packaging printing industry. There are already several large-scale printing companies in China that use this equipment for production. The process will also be more and more widely used.