Aluminum foil hot stamping fault reason and elimination

Common hot stamping quality faults are analyzed as follows:

1. Hot stamping is not strong.

There are many reasons why hot stamping is not strong, and the processing methods are also different. To sum up, there are mainly the following three kinds.

1 When the hot stamping temperature is low or the pressure is light, the hot stamping temperature and pressure can be readjusted when the hot stamping is not secure.

2 In the printing process, the dry oil added to the ink is too much, which causes the surface of the ink layer to dry and crystallize too quickly, so that the printing foil cannot be hot stamped. The solution is to prevent crystallization from occurring as much as possible during printing. Secondly, after the crystallization is completed, the stamping foil can be removed. After the heating, the printed product is air-compressed and the crystallized layer is destroyed first. India.

3 Adding an appropriate amount of a wax-containing lightening agent, anti-sticking agent, or non-sticky oily substance to the ink may also result in poorly stamped. The solution is to first apply a layer of highly absorbent paper on the printing plate to press it once again, adsorb the wax and non-drying oil on the ink layer, and then perform the hot stamping operation.

2. The hot stamping image is faint and dizzy.

During the hot stamping process, it was found that the failure of the picture and text was faint and dizzy, which was mainly caused by the high stamping temperature and the coking aluminum foil. If the hot stamping temperature of the printing plate is too high, so that the galvanized aluminum foil exceeds the limit that can be tolerated, at this time the hot stamping, the galvanized aluminum foil will expand around, resulting in fainting, hair false phenomenon, must be adjusted according to the characteristics of the aluminum foil The range.

For galvanized aluminum foil coking, the main reason is that the shutdown during the hot stamping process is too long, so that a certain part of the galvanized aluminum foil comes into contact with the electrothermal high-temperature printing plate for a period of time and the phenomenon of heat coking occurs, and the graphic and text will become dizzy after hot stamping. Therefore, in case of shutdown in the production process, the temperature should be reduced or the electro-aluminum foil should be removed. Alternatively, a thick paper can be placed in front of the higher-temperature plate to isolate the electro-aluminum foil from the plate.

3. The writing is vague and pastes.

The main reasons for this failure are the high stamping temperature, the excessive thickness of the electro-aluminum aluminizing layer, the excessive embossing force, and the looseness of the electro-aluminum installation. According to the specific circumstances to take appropriate measures to resolve. Excessive hot stamping temperature is the main cause of illegible writing and stencil. During the hot stamping process of aluminum foil, if the printing plate temperature is too high, the film base layer and other film layers will transfer and stick, resulting in illegible writing and stencil. Hot stamping should be based on the temperature of the application of aluminum foil, the appropriate reduction in the stamping temperature. In addition, we should choose a thin aluminum aluminized layer, adjust the appropriate pressure, and properly adjust the pressure of the pressure roller and the winding roller tension.

4. The edges of the picture are uneven and unclear.

When electro-aluminum hot stamping, flashing occurs at the edges of the graphic and affects the printing quality. The main reasons for this phenomenon are: uneven pressure in the printing plate, which is mainly due to uneven layout during plate loading, causing uneven pressure on various areas of the plate, some pressure is too large, and some are too small, thus making the graphic Uneven stress, the surface of the stamping foil is not smooth, and the adhesion of the various parts and the substrate is not the same, resulting in uneven printing. Therefore, the printing plate of the electro-foiled aluminum foil must be filled with a flat pad to ensure that the pressure of the hot stamping is even, so as to avoid unclear graphics.

If the pressure of the printing plate is too large during hot stamping, it may cause the image printing to be uneven. At this time, it is necessary to adjust the stamping pressure to an appropriate level. It is necessary to ensure that the pad of the embossing mechanism should be accurately fitted according to the area of ​​the pattern, without shifting or moving. In this way, it can be ensured that the graphic and pad overlays are matched during hot stamping and the hair around the graphic is avoided. Also, the pressure of the same plate after stamping is not uniform. This is because the size of the picture area is very different. The pressure of the large area of ​​the picture should be increased. The pressure of the area can be corrected and adjusted by the pad method to make it equal. Finally, if the temperature is too high during hot stamping, the image imprinting will be uneven. Therefore, according to the characteristics of the aluminum foil, reasonable control of the printing temperature of the printing plate, in order to ensure that the four sides of the picture is smooth, smooth, not hairy.

5. The graphic prints are incomplete and lack of strokes.

This failure is mainly caused by the delivery of electro-aluminum foil, printing plates and other reasons. For example, the printing plate is damaged or deformed, which is one of the important reasons for the incompleteness of the graphic print. Therefore, if the plate is found to be damaged, the plate should be repaired or replaced immediately. The deformation of the printing plate does not allow the printing plate to withstand the applied stamping pressure, and the printing plate should be replaced and the pressure adjusted. If the electro-aluminum foil cutting and conveying deviation, when the electro-aluminum foil is cut horizontally when the margin is too small or when the skew occurs when the skew is unrolled and conveyed, the electro-aluminum foil will not coincide with the plate and the graphic and text will be partially exposed. incomplete. In order to prevent such problems, it should be neat and tidy when cutting electro-aluminum foil, and the margin size should be appropriately increased. Improper speed and tightness of the electro-aluminum foil can also cause such failure.

The galvanized aluminum foil feeding and receiving device is loosely displaced, or the galvanized aluminum foil core is loosened from the winding shaft, the unwinding speed is changed, the degree of tightness of the electro-aluminum foil is changed, the position of the hot stamping position is deviated, and the image is incomplete. . At this time, the winding and unwinding device should be adjusted. However, if the hot stamping foil is too tight, the pressure of the pressure roller and the tension of the winding roller should be properly adjusted to ensure the proper speed and tightness of the galvanized aluminum foil. Hot stamping materials and hot stamping material is not suitable or when spraying too much dust will also appear this kind of failure, should pay attention to adjust. In addition, the position of the printing plate at the bottom plate moves and falls, and the pad of the embossing mechanism shifts, so that the normal hot stamping pressure changes and unevenness results in incomplete image printing. Therefore, during the electro-aluminum hot stamping process, the quality of the stamping should be checked frequently, and the quality department should be immediately analyzed to check the printing plate and the backing material. Found that the printing plate moves or the pad shifts, adjusts in time, puts the printing plate and the padding back in place to fix.

6. Hot stamping or texting.

During hot stamping, there are no visible or hot stamps in the graphic text. The main reasons are:

1 The hot stamping temperature is too low, and the hot stamping temperature of the printing plate is too low to reach the minimum temperature required for the galvanized aluminum foil to separate from the substrate and transfer to the substrate. When the stamping is performed, the galvanized aluminum foil is not completely transferred, resulting in a graphic transmission. Flowers, open bottom or hot stamping are not available. When this quality problem is discovered, the temperature of the hot plate must be adjusted properly in time until it is printed.

2 Small hot stamping pressure. During the hot stamping process, if the platen stamping pressure is too small and the pressure applied to the galvanic aluminum foil is too light, the galvanic aluminum foil cannot be transferred smoothly and the hot stamping artwork is incomplete. At this time, the hot stamping pressure should be increased.

3 The background color is excessively dry and the surface is crystallized. The underlying ink layer on the surface of the substrate is too thick and excessively dry, and crystallization will occur, so that the galvanized aluminum foil will not be hot stamped. When hot stamping, the dryness of the background color is printed immediately within the printable range. When the background color is printed, the ink layer should not be too thick. When the printing volume is large, it is necessary to print in batches and shorten the production cycle. Once the crystallization phenomenon is found, the printing should be stopped immediately.

4 The type of the galvanized aluminum foil is incorrect or of poor quality. This will also cause problems with the quality of hot stamping. Should replace the type of suitable, good quality, strong adhesive power of aluminum foil. Stamping larger area of ​​the substrate, can be hot stamped twice in order to avoid hair, exposed bottom and hot stamping is not on.

7. The pattern is hot and matte.

Most of this is because the hot stamping temperature is too high, and the temperature of the hot plate should be properly reduced. In addition, it is necessary to minimize the number of empty cars and reduce unnecessary parking because empty cars and parking will increase the temperature of the hot plate.

8. The stamping quality is unstable.

Use the same material, but the quality of stamping is good or bad. The main reasons are unstable material quality, temperature control of the electric heating plate, or loose pressure adjustment nut. The material can be replaced first. If the failure persists, it may be a problem of temperature or pressure. The temperature and pressure should be adjusted.

9. Leaking the bottom after hot stamping.

The main reason is that the pattern of the object to be heated is too deep, and the pattern of the material to be heated is replaced; the pressure is too low and the temperature is too low to increase the pressure and raise the temperature. All in all, the appearance of hot stamping failures in electro-aluminum is due to many factors. In addition to the hot stamping temperature and pressure speed, we must also pay attention to printing materials or replacement of anodized aluminum. We should carefully analyze them in order to prescribe the right medicine and eliminate them. malfunction.