In recent years, with the improvement of the appearance and quality requirements of commodity packaging, printing technology and packaging technology have made great progress, post-press processing technology has been vigorously developed, and electroplated aluminum hot stamping has been used as an imprint. As part of the post-processing, the changes in the past few years have even been even greater. The combination of new technologies, new processes and various technologies has resulted in good results in gloss, three-dimensional, metal and anti-counterfeiting properties of printed prints after hot stamping, especially at present. A wide range of three-dimensional hot stamping technology makes the packaging of the goods look high-end, exquisite and full of personality. Currently, the technology is mainly used for greeting cards, bookmarks, trademarks, tobacco and alcohol packaging and various high-end packaging boxes. Dongguan Bit Packing is one of the few companies in China that can apply the blanching process to bags.
3D bronzing process requirements:
The first is electrochemical aluminum foil
The electrochemical aluminum foil is usually composed of 4 to 5 layers of different materials, such as a base film layer (polyester film), a release layer, a colored layer (silver anodized aluminum without a colored layer), an aluminum plating layer, and an adhesive layer.
The main functions of each layer are:
The 1 base film layer is mainly used to support other layers.
The function of the 2 peeling layer is to separate the electrochemical aluminum foil layer from the base layer, which determines the transferability of the electrochemical aluminum layer.
3 The main role of the colored layer is to display the color of the anodized aluminum and protect the underlayer. Common colors are: gold, silver, brown, light blue, black, red, green, etc., of which gold and silver are the two most commonly used colors.
4 The role of the aluminized layer is to present a metallic luster.
5 The role of the adhesive layer is to bond the hot stamping material.
The adhesive materials constituting the adhesive layer are different and the adhesiveness is also different. In order to accommodate the different surface properties of different hot stamping materials, electrochemical aluminum will use different bonding layers to form different types of anodized aluminum.
The hot stamping speed and quality are mainly affected by the peeling layer and the adhesive layer. If these coatings are not sensitive to heat, the hot stamping speed will be reduced accordingly. In the past, due to the limitation of heat transfer rate, the flat stamping speed was lower, less than 5,000 sheets per hour. However, some of the world's leading suppliers of anodized alumina have enabled the production of anodized aluminum to meet the needs of the industry. Printing speed requirements, the Swiss Bobst hot stamping machine achieved a hot stamping speed of 7,500 sheets / hour. Since the three-dimensional bronzing forms an embossed pattern, the control of temperature, speed and pressure is different from the control of ordinary bronzing. Therefore, the requirements for hot stamping foil are also different from ordinary hot stamping. Stereo hot stamping should be used when using hot stamping foil. Hot stamping foil, but you can not use ordinary hot stamping foil as a three-dimensional hot stamping, otherwise it will produce poor quality or other accidents.
Second, temperature, pressure, speed
Temperature, pressure and speed are the three main elements of hot stamping technology. The quality of hot stamping can only be controlled by controlling the relationship between the three. Since the three-dimensional bronzing is bronzing and embossing at one time, the temperature requirement is high, the ordinary bronzing temperature is only 70 ° C ~ 90 ° C, and the three-dimensional bronzing can be completed at about 150 ° C. If the temperature is too low, the electrochemical aluminum adhesive layer and the release layer may not completely melt, and the electroformed aluminum foil may not completely transfer during hot stamping, resulting in hot stamping or exposure. If the temperature is too high, the paper will be excessively deformed, the image will be confusing, the writing will be unclear, and even the electrochemical aluminum discoloration will occur. At the same time, hot stamped sheets may expand too much due to high temperatures, but not precisely to the bottom. The molds are combined to create a poor stamping phenomenon. Therefore, temperature control is the first of three major factors.
Hot stamping pressure refers to the pressure on the hot stamping plate. During hot stamping, the molten anodized aluminum binder layer is pressed to complete the transfer of anodized aluminum, so the magnitude and uniformity of the pressure directly affects