Common Fault Analysis and Solutions in CTP Equipment Plate-Making Process

Contrary to the dominance of offset printing in the publishing and commercial printing markets, the packaging printing and label printing markets can be said to have the greatest degree of compatibility with various printing methods, especially in the label printing market, flexo printing, offset printing, embossing, Gravure printing, screen printing, and digital printing are all leading the way. Among them, flexo printing, offset printing, and letterpress printing have become the three major printing methods for self-adhesive label printing. Therefore, both offset printing plates and embossing resins can be output. The three-in-one CTP equipment of printing plate and flexo printing plate has gained a high degree of attention in the field of self-adhesive label printing.

Plate-making common problems and solutions

1. Some outlets are uneven

If after plate making or printing on the machine, it is found that there are thin lines and uneven dots on the part of the printing plate, or there are no problems within a circle, it is likely that there is dust and residual glue on the surface of the plate mounting cylinder (the tape for pasting the end of the plate) The degumming is very serious, and the residual glue is left on the surface of the cylinder) and other impurity particles, resulting in the inability of the flexo printing plate to be completely bonded to the cylinder, and quality problems will occur on the printing plate corresponding to the place where there are impurity particles.

This kind of problem stems from the lack of daily maintenance and the problem of the operating habits of the plate-making workers. First of all, wipe the cylinder regularly. Before loading the plate, you should also use a clean, lint-free, and non-lint-free silk cloth dipped in a little neutral detergent to wipe the surface of the cylinder and the back of the plate; There are no impurity particles on the plate to prevent impurities from sticking to the back of the plate. In short, the above problems can be avoided by doing daily maintenance and careful operation.

2. There is a virtual border at the beginning or end of the page

The imaginary edges at the head and tail of the printing plate (offset printing plate) may be due to the looseness of the head clamp and the tail clamp of the printing plate, or the lack of vacuuming force.

First of all, it is necessary to check whether the clamp can complete the clamping action up and down and whether the clamping is reliable. If the plate clamping factor is ruled out and it is confirmed that the vacuum is not compact, turn on the vacuum to check whether the air extraction pipe is leaking, whether the interface is loose, whether the nozzle is blocked, whether the air extraction hole on the roller is blocked, etc. To prevent such problems, daily maintenance must also be strengthened.

3. CTP device communication is abnormal

The abnormal communication of CTP equipment is mainly manifested in that the software page on the screen turns gray, the communication port cannot be connected, the transmission of graphic files is blocked, and the network cannot be connected, etc. Most of the problems come from insufficient network speed or loose transmission lines.

In case of this problem, first, check whether the emergency stop switch is reset; pull up the emergency stop switch, and then check whether the network cable and communication cable is tightly connected and whether the contact is firm; other faults should be removed by professional maintenance personnel.

When the equipment is installed, the network cable and the communication cable are protected by the wire groove, which can prevent people from walking, stepping on it, causing wear, or tripping it. In addition, placing the main chassis in a suitable position can also reduce the chance of network cables and communication cables being pulled off.

4. The vertical thin lines on the printed matter have the jagged feeling

This kind of situation is more common on the black version, which is caused by the screen angle. The solution is to replace the color version with a screen angle of 45°. For example, the problematic black version is 75°, while the magenta version is 45°, you can exchange the screening angles of the black version and the magenta version. 45° is the most familiar and best observation angle for human eyes. The thin lines observed at this angle will appear straight and will not produce jaggedness.

There is a default allocation method for the screening angle of each color plate in the software, but users are allowed to set new templates according to the characteristics of the most frequently printed products of their own enterprises, so as to facilitate calling.

Basic maintenance of equipment
The basic maintenance of equipment mainly revolves around the equipment cover, roller surface, ball screw and linear guide, equipment interior, electrical components, and optical lens. The maintenance cycle of these parts is not static and can be adjusted according to the actual situation. For example, the tape used to stick the end of the plate is very sticky in summer, and the degumming is very serious. It is easy to leave residual glue on the roller. Cleaning needs to be more frequent, and it must be wiped thoroughly with a lint-free and powder-free cloth dipped in alcohol.

In short, whether the daily maintenance is done well or not will directly affect the quality and efficiency of plate making, etc., as the saying goes, "If a worker wants to do a good job, he must first sharpen his tools." The service life of the equipment is also closely related to daily maintenance, which cannot be sloppy.


Huida Print-All Technology company is an advanced and professional manufacturer of producing printing plates, mainly selling CTP, CTCP, and PS plates as well as offering ODM/OEMs, especially for the offset. For more information, please click the official website link here: