The development of hot stamping technologies
Recently, with the improvement of hot stamping materials and process ability, and the use of new machine equipment, inland hot stamping has made much progress. High speed hot stamping, three-dimensional hot stamping, holographic orientation hot stamping and printing after hot stamping have been using extensively into cigarette.
Three-dimensional hot stamping is an complex technology that combined hot stamping with concave-convex press technology. By using corrosion and grave, it makes hot stamping and concave-convex pattern a negative concave and positive convex, realizing the hot stamping and concave-convex press for one time. This process reduces wastes and improves producing efficiency and products quality.
Because the products made by three-dimensional hot stamping are three-dimensional, it is unable to print on them, so we must use the design of hot stamping after printing. At the same time, it is unable to use cold stamping to produce due to its requirements of high-precision and high quality. Three-dimensional hot stamping equipment usually has flat and round types.
Flat three-dimensional hot stamping equipment includes Boast equipment, which is developing for high speed, high precision, using convenience. It is the main equipment in three-dimensional hot stamping. Boast hot stamping machine has reached the speed of 7500strech per hour, the precision can be remained between 0.1 and 4 mm, and is one of the most advanced hot stamping machines.
Round hot stamping is usually used in processing volume paper. Because it is connected with wire, we can avoid the bubble that may have in flat hot stamping. It is high speed and high quality. But hot stamping edition and substrate convex are all round, process is more difficult and the cost is much more high. The impact of heat transfer is not very good. So it is often used in the big output and high quality goods such as cigarette box, wine box and health care products.
Because high grade cigarette is popular with soft packaging, more and more technology is using this method to package. The convex print and orientation hot stamping of soft paper complete the hot stamping and convex press at one time. The products are elegant and beautiful and have no crooked convex press. But this technology is more difficult, and has high requirements of hot stamping edition, holographic film, hot stamping machine. Each operation is strict. But because of this feature, it is very difficult to imitate.
Holographic pattern hot stamping: light holographic pattern uses the theory of light interfere, and is made by using the way of space frequency coding. Because the light holographic pattern has the features of beautiful color, pattern reality, good light changing impacts, high information technology content, it is using into the field of preventing illegal.
The newly light changing pattern has been obviously distinguished from HOLOGRAM holographic pattern. Some holographic pattern now has the function of identification. The theory of holographic hot stamping is that heating and melting glue and release coating by using hot stamping printing model. Under proper press, separating the holographic stripe and PET substrate, and then bonding the aluminum and products.
Holographic hot stamping mainly has normal stamping and orientation stamping. The special holographic hot stamping is becoming more and more popular recently. It means that hot stamping the special aluminum on the special cigarette by using imitation identification. The technology of holographic hot stamping is very difficult, not only does it require the high performance and high precision of special holographic machine, but it also requires the high qualified aluminum. Good cigarette products can be made when the process is controlled seriously.
Cold stamping is a technology which is first used in America printing industry. It completes the aluminum transfer under cold conditions. The special aluminum used in cold stamping needs no glue on its side, we just need to glue on the special fields when printing. Under the performance of glue, aluminum can adhere to the products when transferring.
Cold stamping prints UV oil firstly. After drying, printing special UV glue on the space of oil surface which is needed to be hot stamped. Then evaporating the water in glue and forming a high glued level. Then under the performance of expansion cylinder, we connect aluminum with glue. Because the performance of glue is very good, the parts will be placed on the product surface. The other parts of aluminum will rank waste like other normal shot stamping. The aluminum pattern transferred into the surface of products, so the adhesion is not very good. We must protect aluminum pattern by using light and membrane on the products.
Comparing with national hot stamping, cold stamping has high speed and can save sources. The material can be used in many fields. We can do sold stamping on the paper which is sensitive to heat and some films. Replaced the expensive metal expansion cylinder by normal soft edition, so it reduces the producing costs and times, and it also reduces the pollution in metal corrosion process.
Cold stamping is limited by the condition of glue and metal foil, and it has its disadvantages. For example: products must use lights and films to protect patterns after cold stamping. So it increases costs and the complex of producing. It is not suitable for materials with shrinkage character, such as PVC and PE film. Because the leveling property of UV glue is bad, the surface smooth is bad after drying, which will result in bad shining features, diffuse reflection and bad effects. The key of cold stamping is UV glue and special metal foil. It really has broad developing prospects.
Printing after hot stamping: in order to extrude the pattern and identification on the cigarette box, some printing industry now have made a new technology, which prints patterns after hot stamping aluminum. The new technology makes the theme of cigarette more vivid and active.
Printing after hot stamping is a new creation in the cigarette design industry. The technology has high requirements to aluminum. The key is that aluminum stamping must has good adhesion and the aluminum should not be counter pulled by the printing oil. Counter pull affects the quality of cigarette box and aluminum will pile up on the rubber blanket. To some extent, it will result in losing pattern branch and printing difficulty. With machine turning round, the aluminum powder will transmit into the ink roller system, which will abrade the ink roller quickly. So we should use proper aluminum to protect aluminum adhere to paper according to printing paper.
Besides the requirements of stamping accuracy, smooth and slight surface, balancing and equality press, no bubble and filling in, the edge of the hot stamping patterns should not have obvious impress, and the aluminum should have good adhesion performance, and have no obvious scratch phenomenon. As we all know, the process of hot stamping means heating and pressing on paper. To glass card, we should pay much attention to protect semi-finished products. We should also reduce the possibility of distorted paper. This all will benefit to hot stamping process and will increase the pass percent of products.
The embossing process is to emboss lines needed on the aluminum patterns with micro pressure version. The products have shot stamping and embossing impacts and also have good metal performance.
