Board printing machine: Faults and effective solutions in using

When we use the board printing machines, some machine failures often occur, so how to solve this kind of problem?

1.Paper break fault
Paper break is a very headache, mainly due to the following reasons:
(1) The edges are cracked, crimped, bruised or glued on the sides. When glue is stuck to the tight edges or sides of the paper roll, the paper tape is fragile, which affects the normal paper supply. It is found that this kind of phenomenon can be used to wet the curled edge or the side with glue with water brush, and the fault will be eliminated.
(2) The core of the paper roll itself is not round. The operator can judge whether the eccentricity of the core is too large based on experience, and change the paper in time or notify the machine manager to reduce the speed to avoid it according to the situation.
(3) The lifting speed is too fast or the tension is too large. The paper has a tension limit. When increasing the tension, try to stay away from the limit tension. At high speeds, a very small change will also produce a very large stress, which will lead to paper breaks.
(4) The core shaft of the paper guide roller is loose, the levelness and parallelism are inaccurate, and the core shaft or bearing is worn out. Enough attention should be paid to machines that have been used for a certain number of years. Maintenance personnel and operators should check the working conditions of the paper guide rollers in time.
(5) Too much ink deposits on the paper guide roller. After the machine is turned on for a long time, the deposit of ink dirt increases the radius of each roller, which increases the tension. When the tension reaches the limit value, the paper breaker will cut the paper protectively. Therefore, the ink dirt deposited on the paper guide roller should be removed in time.
2.Water filling, inking and imprinting faults
(1) Water supply part
Water supply devices can generally be divided into indirect water supply and direct water supply. No matter which method is used for water supply, the purpose is to fully wet the printing plate and maintain the balance of ink and water. The specific manifestations of various failures are: excessive water volume will cause the ink to lose its luster, gray and dull, the ink is not full, and ink emulsification will occur in severe cases; if the water volume is too small, the printing plate will not be fully wetted, resulting in distortion of graphics and text. Phenomena such as ambiguity. The specific elimination method can be adjusted according to the structure of the water supply mechanism and the function of each component.
If you can check the working condition of the water bucket baffle motor or the nozzle solenoid valve, whether the pressure between the water transfer roller, the water string roller, the plate roller and the plate cylinder is normal to eliminate the fault, you should pay attention to the pressure at both ends of the water roller. To be adjusted to a balanced position. Normally, the water roller and the nozzle of the water bucket should be cleaned in time, and the pressure between the water rollers should be checked.
(2) Ink supply part
The ink supply mechanism is composed of an ink fountain roller, an ink transfer roller, an ink string roller, and a plate ink roller. The common faults are: insufficient ink supply, large ink supply, unstable ink supply, etc. The above faults can be eliminated by checking the working conditions of the ink fountain roller and the ink nails and whether the pressure between the ink rollers is normal. When adjusting the ink roller, it is necessary to adjust and test whether the left and right balance of each rubber roller is consistent. At the same time, it is necessary to ensure that the pressure of the ink roller against the plate is moderate. Avoid the inconsistency of the inconsistency between the front and back of the ink color of the printed product, and carefully check whether the surface of the rubber roller is smooth and clean, and whether there are big hard scratches such as indentation, scratches or poor adjustment of the ink, which may cause local conjunctiva and crystallization. . Due to the large temperature difference between winter and summer, the pressure can be appropriately increased in winter and reduced in summer.
(3) Imprinting part
The imprinting part is the core part of the printing unit and the most precise part of the design and manufacturing. Generally, manufacturers do not allow users to adjust pressure and other mechanical parts. Printing pressure is an important factor for the completion of ink transfer and transfer during the printing process. Moderate printing pressure is a reliable guarantee for the printed product layout, text, and pattern to be clear and clean, the text is not deformed, and the ink color is uniform. The main faults are weak ink color, unclear dots, and text deformation. The reason is insufficient ink transfer, which is caused by the loss of elasticity of the blanket or the lining is too small. Just replace the blanket or increase the thickness of the lining appropriately. You can troubleshoot the problem.

Now, for the use of the cardboard printing machine, what problems have you encountered?