From the end of the 20th century rainbow laser materials in the market, in the past 20 years its application has been widely used in the field of packaging and printing, laser holographic film because of the overall light effect, anti-counterfeiting performance, there are obvious advantages, laser film in tobacco and alcohol, cosmetics, high-grade food and other fields become standard packaging. And in the laser film packaging market, technology and materials have been introduced, such as coated laser film technology, laser transfer printing to laser positioning printing and other developments, the material is also from plate seam laser film to plate seam laser film. Although the technology and materials are constantly updated, but the laser film in the production process is still inseparable from the following several processes: laser molding plate, laser printing, coating, cutting, transfer, curing and other processes. After finishing the film, several key steps are introduced.
Make laser mold plate(Hologram master)
System of laser molded version is one of the core of the laser film production, pressure version of casting level determines the quality of the laser film, laser casting moulding edition and printing process of plate making completely different, have different requirements, is made of special metal chips after laser molded version of electroforming, and plate with strong hardness and flexibility, not deformation under high temperature baking, And under the magnifying glass observation can not see any minor defects in the layout. Therefore, laser molding version of the casting quality requirements are very demanding. Plate material is also very expensive, so use very careful, in the wipe, maintenance can not have any small collision, can not have oil, water splash onto the laser mold plate, responsible for the product scrap.
Coating process
General laser film has two kinds of materials, the distribution of BOPP and BOPET. BOPP can be directly pressed on the laser graphics, but BOPET can not, if you want to press the laser graphics on the BOPET base film, you must first coat the PET base film with a very thin special paint, and then press the laser graphics. In the process of coating special coatings, not only to ensure the appropriate viscosity, but also the coating environment has higher requirements, such as sealing, dust-free, constant temperature, constant humidity, etc.
Pressure laser graphics
The principle of pressing the laser image and text is to press the laser mold plate directly on the film substrate or special coating at high temperature, forming uneven and different sizes of light refraction points, after illumination, the diffuse reflection of different wavelengths of light will make the laser film present rainbow light.
Pressure laser graphics, to master the temperature, speed, tension three elements, if the three elements of control is not accurate enough, there will be serious color, black spots, white spots, water lines, wrinkles, cloud flowers, pitting and other problems, sometimes there will be laser graphics and light column deformation and tension instability and other quality defects. These defects will bring great trouble to the later printing, and even make the laser film unable to be put into printing production.
Vacuum plating
After finishing pressing laser pictures, if you want to achieve the metal effect, you need to spray a layer of metal foil on the pressing laser pictures, mainly using vacuum aluminum plating machine will be different wire atomization through strong current in the vacuum container, covered in the pressing laser film. Plating link can be aluminum, chromium, nickel, copper, iron, etc., can be plated matte surface, light mirror effect, vacuum plating effect depends on the metal material used.
Vacuum plating process is very difficult to operate, take vacuum aluminum plating as an example, due to voltage, current, vacuum, material purity and other factors, the process of aluminum plating may produce aluminum discoloration. Splash, aluminum, black spots, spots, bubbles and other quality defects, will affect the final laser film quality, easy to cause poor transfer and a large number of aluminum phenomenon.
After the vacuum plating process, the surface treatment of the foil must be carried out to improve the printability in order to ensure the smooth processing. There are two main treatment methods: coated varnish (paint) and corona treatment, which can be selected according to the different surface properties of the metal foil.
In addition to the ordinary laser pressure membrane technology, laser holographic anti-counterfeiting positioning laser moulding technology is relatively new high-tech membrane technology, different from ordinary laser film production process, at the time of pressure positioning of laser film, need to calculate well in front of the plate making holographic anti-counterfeiting laser printing position, planted anti-fake pattern in a specific location of laser molded version, and then laser location and moulding, In this way, when transferring the laser holographic positioning film, the anti-counterfeit laser pattern can be transferred to the same position on the printed surface.