Three tips for packaging and printing machine registration

Familiar with the principle of various sets

The gravure printing set is achieved by changing the relative position of the material and the plate roller. The printing position is gradually developed from the initial manual adjustment to the automatic position; from changing the material position to changing the position of the plate roller. The accuracy of the sleeve is continuously improved, and the quality of the printed matter is continuously improved.

Different types of sets have different principles. In longitudinal registration, the position of the swing roller is that the plate roller maintains a stable position. The position of the swing roller is changed by the adjustment motor and the length of the material between the color groups is adjusted to move the position of the material to achieve registration. The registration of shaftless printing machine is to keep the material in a stable position, and the position of the plate roller is adjusted by a servo motor to achieve registration. Lateral registration is to keep the material in a stable position and adjust the position of the plate roller to achieve registration. The positive position device controls the edge position of the unwinding material. Because the printed material will stretch under the action of tension, it will directly affect the registration accuracy, so the stability of the material size is the basis of overprinting. Different materials require different pre-tensioning tensions. The closed loop tension control system maintains a stable tension to achieve a relatively stable material after pre-stretching.

Strengthen inspection of printed materials

Whether the printing material is good or not will have a certain effect on the precise set, and there are many factors that affect the material, such as the material is fleshy (lotus leaf), the stretching of the printing material, the identity of the plate roller, the order of the plate roller Increasing control, control of the concentricity of the plate roller, and correct installation of the plate roller will all have a certain impact on the use of printed materials.

Therefore, the inspection of the material should be strengthened, especially for the material that is suspected of being meaty (lotus leaf), 5 meters of raw material can be taken, and 2 people tighten it to see if there is a slack phenomenon. If the slack is serious, the raw material must not be used . At the same time, the plate roller must be strictly checked before use. The diameter of a set of plate rollers must be exactly the same. In order to overcome the effect of material stretching on the registration, the diameter of the plate roller increases in sequence, and the concentricity of the plate roller must be within the tolerance range Inside. Before installing the plate roller, the surface of the plug and the mounting hole of the plate roller must be carefully cleaned to prevent the inaccurate sleeve position caused by the plate roller jumping due to the presence of garbage.

Check equipment carefully before printing

Before starting to print, the equipment must be carefully checked to ensure that the equipment is not faulty and the accuracy is guaranteed. To confirm that the sleeve device is in the correct working state, the illumination of the scanning head must be sufficient to correctly identify the mark mark; the surface of the reflective plate is smooth and smooth without dirt; the distance between the reflective plate and the scanning head is correct, it can not touch the film, and can Generate enough reflected light.

To determine the appropriate air supply of the equipment, the material does not produce jitter; the appropriate drying temperature should ensure that the ink is dried without deforming the film; regarding the relationship between the air volume and temperature, ensure that the drying and no material jitter occur Under the premise, priority is given to increasing the air volume. The control of tension is also very important. It is necessary to ensure that the material is stretched without serious stretching; the diameter and circumference of the plate roller must be carefully confirmed and then input into the system to ensure identity. The pressure of the pressure roller must be appropriate, and the position of the film will not be changed, and at the same time, the film will not slide, which meets the requirements of the sleeve.

(Author: Shanghai Toppan Co., Ltd.)