Stamping Materials and Their Selection (3)

(5) Electrochemical aluminum foil processing in hot stamping process. Electrochemical aluminum foil varieties, manufacturing process, batch, performance vary, in addition to the correct selection should also pay attention to the processing of processing. Because the stamping materials are generally very intuitive, the hot stamping effect directly affects the quality of the book. The hot stamping in the bookbinding process is the main part of the whole process.

1 Before stamping a new processed product or a new type of galvanized aluminum foil, a simple visual inspection of the galvanized aluminum foil should be carried out. The method is to see if the model is correct; open the rewindered galvanized aluminum and observe the surface of the film. Whether there are scratches, sand holes, wrinkles, and whether the handle feels smooth; observe whether the brightness of the aluminum is in conformity with the requirements, and the quality of the reflective aluminum should be strong and shiny. If you use the instrument to measure, you can get accurate and reliable data, the light reflectance of the galvanized aluminum foil should reach about 85% evenly. If unconditionally available visually determined.

2 Stamping Electroformed aluminum plates are generally available in copper plated, zinc plated, and copper plated zinc plates. The use of copperplate is preferred because the copperplate has strong heat resistance and certain elasticity. It is more durable than other plates and has a good hot stamping effect. If you are printing sheet-fed or small-batch work pieces, you can use the zinc plate (the price is cheaper than the copper plate), and use the copper plate for the book cover and large quantities of work. The texture of the zinc plate is too soft and can not withstand the processing of too many stampings or high pressure. The plate is easily deformed and the hot stamping effect is poor. The thickness of hot stamping plate is generally 1.5-2.5mm. According to the specific conditions of the material to be scorched, different thickness, select the appropriate thickness of the plate. If the hot stamping version is too thin, there will be phenomena such as blurred hair and dirty printing after the hot stamping. If it is too thick, it will cause waste.

The hot stamping printing plate used in hot stamping is generally processed externally. Before use, it is necessary to check whether the layout has burr, uneven edges and corners, and unclear graphics and other ills. Corruption is performed on the unqualified place and hot stamping is performed on the plate.

3 After the inspection of the electrified aluminum foil is completed, the hot stamping plate shall be hot-tested, and the aluminum foil shall be cut to an appropriate width according to the size of the hot stamping area. Then the temperature of the stamping plate shall be adjusted and the stamping time must be mastered. Pressure can start hot stamping. Hot stamping process to remove the correct stamping material, the most important is the temperature, time, pressure control, these three points is the main part of the hot stamping process.

a. Mastering pressure. The size of the stamping pressure should be determined according to the nature of the material to be pressed, the thickness and the hot stamping form. The pressure is so large that the paste is not paste and the mark is clear and bright; the pressure is not strong enough to fall off, and it is not appropriate to make flowers. If the same version of the plate, hot stamping two kinds of size and size of the bead of the graphics, to grasp the unit area pressure equal, the greater the hot stamping area, the hot stamping pressure should be greater, and vice versa is small.

There are two ways to adjust the pressure of the stamping machine. One is automatic and the other is manual. Automatically can be adjusted according to the thickness and nature of the material to be heated; the manual one mainly grasps the pressure after the material is touched. This is very important in operation. Automatic hot stamping adjustment hot stamping pressure, is controlled by the data, more convenient, but encountered in the thickness of the material is not equal, there will be quality problems; while the manual is cumbersome, but the pressure can be freely controlled, not subject to be hot With thin effects.

b. Mastering of stamping time and temperature. Hot stamping time and temperature are determined according to the texture of the material to be heated and the hot stamping form. Hot stamping time is too long, the temperature is too high, there will be paste version, the picture is not clear and other ills, otherwise there will be hot stamping, hot after the fall off, dull, hair and other ills, otherwise there will be hot stamping Not on the hot, off, dull, hair and other ills. Both time and temperature can be fine-tuned during operation. If the temperature is slightly higher, the time can be shortened. When the temperature is slightly lower, the time can be longer. The gap between the two adjustments should not be excessive and should be controlled within a certain range.

Some hot stamping machines are relatively free from temperature and wetness, and operators rely on their senses to grasp, such as the method of dripping water, and the method of touching the hands to test the temperature. The modern production uses data control, which is both economical and scientific. Therefore, it is necessary to increase the temperature display device and strive for scientific production. Stamping time and temperature are listed in Table 2-6.

Table 2-6 Hot Stamping Temperature and Time Reference Table