Hot stamping process of carton
The carton adopts the hot stamping process for two purposes, one is to use it to increase the added value of the packaged product, and the second is to give the packaged product a higher security, while hot stamping can show the personalization of the product packaging and it is safe and environmentally friendly . There are many factors that affect the hot stamping effect of the carton, such as hot stamping equipment, hot stamping plates, hot stamping materials, hot stamping temperature, hot stamping pressure, hot stamping speed, etc.
Hot stamping equipment
In the hot stamping process of the carton, the choice of hot stamping equipment is the key factor to determine the hot stamping effect. At present, the more common hot stamping machine is divided into three types from the working principle: flat pressing, round pressing and round pressing.
In the flat pressing hot stamping process, the anodized aluminum foil and the hot stamping plate surface are in contact with the stamping at the same time, so the larger the hot stamping plate surface, the more likely to be hot or hot stamping and other phenomena. Therefore, when hot stamping a large plate, it is best to use a hot stamping device with a round or round flattening structure. During the hot stamping process, the anodized aluminum and the hot stamping plate are in line contact, rather than separating and transferring a large area in an instant. This is conducive to the uniform separation and transfer of the layer of anodized aluminum foil to the printed product, which can better avoid problems such as flowering and hot stamping. Therefore, in the carton hot stamping process, the appropriate hot stamping equipment should be selected according to the actual situation.
Hot stamping materials
Hot stamping materials generally include anodized aluminum hot stamping foil, pigment foil, ordinary hot stamping foil, laser hot stamping foil, tipping paper hot stamping foil, etc. The more commonly used is anodized aluminum hot stamping foil, which is the main material for hot stamping Its thickness is generally 6 ~ 35μm, commonly used is 12μm. Generally speaking, the graphic information of thin anodized aluminum hot stamping foil is relatively clear, and the thick anodized aluminum hot stamping foil tends to cause undesirable phenomena such as blurring of graphic information during hot stamping.
The primary influencing factor of the carton hot stamping effect is the hot stamping plate. Only when a high-quality hot stamping plate is guaranteed can a good carton hot stamping effect be achieved. The hot stamping plate is mainly made by the photo-etching process and the electronic engraving technology. The hot stamping plate is usually made of copper plate zinc plate and silicone plate. The copper plate material is exquisite, and the surface finish and heat transfer effect are superior to the zinc plate. The use of excellent copper hot stamping plates can improve the gloss and contour clarity of hot stamping graphics. The hot stamping and embossed copper plate is made by a new process of pre-coated copper plate. The graphics are clear and heat-resistant, pressure-resistant, and the pattern is perfect. The laser refraction effect can be fully exerted. It is the first choice for high-end packaging cartons. The traditional photo-etching technology for making hot stamping plates is simple and low cost, and is mainly used for hot stamping of text, thick lines and general images. The electro-engraving technology is required for hot stamping plates with finer and uneven thickness.
Hot stamping temperature
The hot stamping temperature is an important guarantee for the hot stamping effect of the carton. The most suitable temperature in the hot stamping operation is to transfer the hot stamping foil with the lowest and clear and complete standard. The hot stamping temperature of the flat pressing hot stamping machine is about 110 ℃, and the hot stamping temperature of the flat pressing round or circular pressing hot stamping machine is 140 ～ 150 ℃. Usually, the most suitable temperature needs to be found by the test method. If the temperature is too high Will cause damage to the hot stamped product and make the stamped text blurred. If the hot stamping temperature is too low, the adhesive layer of the anodized aluminum foil is not melted enough, and there will be a problem that the hot stamping is not strong or the handwriting is not even hot. If hot stamping and embossing are carried out together, because the hot stamping and embossing are completed in one operation, the hot stamping temperature at this time is higher than the temperature during hot stamping alone, and the temperature is generally controlled at about 150 ° C.
Hot stamping pressure
In the carton hot stamping process, the hot stamping pressure is the basic element to achieve the hot stamping of the carton and is also an important factor affecting the carton hot stamping effect. Therefore, the appropriate hot stamping pressure is an important basis to ensure the smooth transfer of the aluminum foil layer. If the hot stamping pressure is too large, there will be faults such as paste, burrs, bumps or thickening of the print; on the contrary, it will cause poor affinity between the electrochemical aluminum foil and the printed product, and even the hot stamping foil and the paper cannot be adhered to the hot stamping foil. Cut the hot stamping area. In general, the stamping pressure should be appropriately larger to ensure that the force is sufficient and uniform, so as to ensure the complete transfer of the electrochemical aluminum foil layer. However, if the hot stamping and embossing are completed at one time, the pressure needs to be readjusted when starting the hot stamping and embossing operation. The hot stamping pressure on the entire hot stamping plate is required to be uniform on the upper, lower, left, and right sides. With a clear level of unevenness, you can start the normal hot stamping and press the unevenness. Because the hot stamping and embossed plate are corroded once, the concave surface is relatively uneven during the corrosion. In hot stamping, an elastic liner such as a plastic film can be appropriately cushioned according to the situation to reduce the unevenness and cause anodization The disadvantages of hot stamping.
Hot stamping speed
The hot stamping speed often reflects the contact time between the paper and the anodized aluminum hot stamping foil during hot stamping. The hot stamping speed depends on the size of the hot stamping area and the temperature of the hot stamping machine, because it directly affects the firmness of the hot stamping. An important factor affecting the effect of hot stamping. If the hot stamping speed is too fast, then the contact time between the electrochemical aluminum foil and the paper surface will be reduced accordingly. Then the separation and transfer speed of the electrochemical aluminum foil layer will be slow, and there will be problems such as hot stamping or imprinting; on the contrary, it will affect the quality and production efficiency of hot stamping. The speed of hot stamping is also closely related to hot stamping equipment, hot stamping materials, environment, and types of substrates.