Hot stamping or texting

During hot stamping, there is a pattern or a hot stamp on the bottom of the picture. The general reason is that the hot stamping temperature is too low, the pressure is too low, and the underlying ink layer is crystallized.

(1) The hot stamping temperature is too low. 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 the graphic text, the exposed bottom, or the hot stamping. on. 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 electrodeposited aluminum foil is too light, the galvanic aluminum foil cannot be transferred smoothly and the hot stamping graphic is incomplete. Found that this situation should first analyze whether it belongs to the hot stamping pressure, and observe the severity of imprint marks, such as the hot stamping pressure is small, the 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 printing the background color, 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 appropriately. Once the crystallization phenomenon is found, the stamping pressure can be increased appropriately. When the amount of printing is small, degreasing and roughening are performed on the crystallized surface of the ink layer.

(4) The type of galvanized aluminum foil is incorrect or of poor quality. When the type of galvanized aluminum foil is wrong or its quality is not good, it also causes problems in the quality of hot stamping. At this time, it should replace the type of aluminum foil with good quality, good adhesion and strong adhesion. Stamping larger area of ​​the substrate, can be hot stamping twice, you can avoid hair, exposed bottom and hot stamping is not on.

The hot stamping of the picture is made

During the hot stamping process, it was found that the images and texts were faint and dizzy. The main reasons were as follows:

(1) Hot stamping temperature is too high. The hot stamping temperature of the printing plate is too high, so that the electric aluminum foil exceeds the limit that can be tolerated. When the stamping is performed, the electricized aluminum foil expands around, causing halo and hair voicing. If this fault is found, the temperature must be set according to the characteristics of the electric aluminum foil. Adjust to a suitable range.

(2) Electrochemical aluminum foil coking. If the machine is shut down too long during the hot stamping process, a certain part of the electro-aluminum foil will come into contact with the electrothermal high-temperature printing plate and the phenomenon of heat coking will occur, and the graphic will be dizzy after hot stamping. During the production process, in case of shutdown, the temperature should be lowered, or the electro-aluminum foil should be removed. A thick paper can also be placed in front of the higher-temperature plate to isolate the electro-aluminum foil from the plate.

Graphical prints are not uniform

When electro-aluminum hot stamping occurs, flashing occurs around the graphic imprint and affects the quality of printing.

(1) The plate pressure is uneven. When loading the plate, if the layout is uneven, resulting in uneven pressure, some places have too much pressure, some places have too little pressure, and the graphics are not evenly distributed, so that the surface of the electrodeposited aluminum foil is not clean and the parts are bonded to the substrate. The force is not the same, causing the print to be uneven. Hot stamping electroformed aluminum foil printing plate, must be flat and solid, ensure uniform stamping pressure.

(2) Printing plate pressure is too high. When hot stamping, the pressure of the printing plate is too large, and it can also cause the graphic printing to be uneven. During the hot stamping process, the hot stamping pressure should be adjusted to an appropriate level.

(3) Impression accuracy of embossing mechanism. The embossing pad of the embossing mechanism should be accurately fitted according to the area of ​​the pattern, without shifting and moving. When hot stamping, the graphic and pad overlays are consistent, and the facial prints will not grow hairy.

(4) Hot stamping temperature is too high. When the hot stamping of the aluminum foil is performed, the high stamping temperature is also the reason why the imprinting of the images is not uniform. According to the characteristics of the electro-aluminum foil, the stamping temperature of the printing plate is reasonably controlled, and the graphic and the four sides are guaranteed to be smooth and free from hairiness.

Paste version

Hot stamping temperature is too high is the main reason for paste version. During the hot stamping process of the aluminum foil, if the printing plate temperature is too high, the film base layer and other film layers will transfer and stick, resulting in paste plate. Hot stamping should be based on the temperature of the application of aluminum foil, the appropriate reduction in stamping temperature.

Graphic imprinting is incomplete

The incompleteness of the graphic imprinting is mainly caused by the reasons such as the delivery of electro-aluminum foil, plates, and the like.

(1) Electrochemical aluminum foil cutting and conveying deviation. When the electro-aluminum foil is cut horizontally, the edge is too small or the skew occurs when the skew is unwound and conveyed. As a result, the electro-aluminum foil does not coincide with the plate and text, and part of the picture is exposed and 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.

(2) Electro-aluminum foil conveying speed and tightness. Electro-aluminum foil unwinding (feeding) and rewinding (pickling) device loose movement, or between the electro-aluminum foil winding core and the reel, the unwinding speed changes, the degree of tightness of the electro-aluminum foil changes, and the graphic and text stamping The deviation occurred in the position, resulting in the incomplete picture. At this time, adjust the winding and unwinding device to ensure proper speed and tightness of the electro-aluminum foil.

(3) Plate shift or pad shift. The printing plate moves and falls in the position of the bottom plate, and the pad of the embossing mechanism is displaced, so that the normal hot stamping pressure changes and is uneven, resulting in incomplete image printing. During the electro-aluminum hot stamping process, the quality of hot stamping should be checked frequently, quality problems should be immediately analyzed, and plates and underlays checked. 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.

(4) The printing plate is damaged or deformed. Printing plate damage is one of the important reasons for the incompleteness of the graphic print. If the plate is found to be damaged, the plate should be repaired or replaced immediately. The plate is deformed so that the plate cannot withstand the applied stamping pressure, the plate should be replaced or the pressure adjusted.

Pull back

Due to the pulling force when the galvanized aluminum foil is separated, the galvanized aluminum foil is not completely attached to the surface of the base ink layer during hot stamping, but some of the affixed aluminum foil still adheres to the base of the base layer, and the base ink layer is also pulled away. The difference between back-drawing and hot-stamping is that: After the hot-stamping phenomenon, the traces of ink are left on the base of the electro-aluminum sheet. To solve the anti-pull phenomenon should use good quality aluminum foil, the background ink must be fully dry, and can not be crystallized, to grasp the background color printing and electro-aluminum hot stamping interval, control the proportion of good dry oil.