3 Common Printing Malfunctions Analysis and Solutions! Contains techniques!

In the process of map printing, problems such as broken lines, missing colors, scratches from hard objects, and inconsistent color stacking of image maps often occur, greatly affecting the quality and production efficiency of map printing. The author has continuously summarized and explored the causes and solutions of faults in the map printing process through years of production practice, and shares them with colleagues here.
Wire breakage issue
01
Root cause analysis
There are two main reasons for wire breakage during the printing process:
One is that the layout is sticky and dirty;
The second is that the original data is missing during plate making or lost during exposure and development.
When there is a wire breakage problem, the first thing to determine is whether it is caused by sticking (sticking the plate). You can use a damp cloth dipped in a small amount of cleaning paste to wrap it on the ink shovel without stopping the machine, and wipe the corresponding water bucket roller according to the position where the plate is dirty. The cleaning paste on the water bucket roller is transferred to the plate through the chrome plated roller and the dampening roller, and the floating dirt on the plate can be removed;
If the above method fails to remove the dirt, it is necessary to consider whether the text and text at the broken line are lost during plate making. After stopping the machine, use a damp cloth dipped in plate cleaning paste to wipe off the dirt on the plate, then wipe it again with a clean damp cloth, and carefully inspect the broken line on the plate to clearly identify the cause.
02
solution

If it is due to dirty layout, you can use a damp cloth to clean the printing plate during the process of finding the cause to solve the problem.
If it is due to the loss of layout graphics and text, it can be resolved in two situations.
One is that there is a problem of broken lines when printing at the beginning. Usually, a touch up pen is used to repair the photocopy, but the touch up pen is thicker. If the line at the broken line is thinner, this method cannot be used.
Through long-term exploration, the author usually uses the top needle puncture method to solve such problems, which connects the acupuncture points into a dotted line to achieve the purpose of filling the gaps.
During the needling process, it is necessary to ensure that the needling line is absolutely consistent with the broken line. The thickness of the broken line is expressed by the depth of the needling. If the line is fine, the needling should be shallow, and if the line is thick, the needling should be deep. The gap between the needling points should be evenly controlled at 0.5mm. During the needling process, the sample should be compared in real time, and after the needling is completed, the needling area should be filled with ink of this color group.
The second is when the issue of broken lines is discovered only after some or all of the printing production tasks have been completed. Usually, all printed products are scrapped, corrected or remade, and then reprinted.
solution
The author's solution to this type of problem is to re plate only the broken lines and corner lines, and overlay them on the printed sheets with broken lines. When the broken lines can be accurately overlaid, the corner lines are trimmed off and only the broken lines are printed.
Lack of color and inconsistent color stacking issues
01
Root cause analysis
The problem of color deficiency and inconsistent color stacking mainly refers to the phenomenon where the yellow, magenta, cyan, and black colors are overlapped during the map printing process and do not meet the requirements of the sample. There are two main reasons for this:

One is that the ink density is inconsistent;
The second reason is that the rubber blanket cushion is damaged, and the cause can be found according to the following methods.
Firstly, check the ink density. Experienced operators can visually detect the depth of ink and adjust the ink in a timely manner to meet the standard ink color requirements. Inexperienced operators can use a reflection density meter to measure the density of each color. A higher density indicates a darker ink color, while a lower density indicates a lighter ink color. Ink can be adjusted according to the actual situation.
Secondly, check if the rubber blanket cushion is damaged. When there is a problem, stop the machine in a timely manner. For areas with obvious uneven ink color, touch the rubber blanket with your hand. If you feel that the rubber blanket has a depression, it means that the air cushion here is damaged.
02
solution
When there is a lack of color or inconsistent color stacking due to uneven ink density, the operator can make appropriate adjustments to a certain ink area or the entire ink area where the ink color is inconsistent.
When color loss or inconsistent color stacking occurs due to damage to the rubber blanket air cushion, operators can use xylene to compress and expand the rubber blanket air cushion and repair the damaged area. If the air cushion is severely damaged, the lining paper at the damaged area should be thickened accordingly to ensure the printing effect.
Excessive graphic and textual issues
01
Root cause analysis
There are three main reasons for the occurrence of redundant text and images:
One is sticky dirt;
Secondly, there may be excess raw data or impurities on the exposed lens during plate making;
Thirdly, if the layout is scratched by a hard object, the following methods can be used to investigate the cause.
After stopping the machine, clean the printing plate with a damp cloth and carefully inspect the excess graphic and textual parts on the plate. If it is due to dirt, wipe it clean with a damp cloth; If there is excess raw data or impurities on the exposed lens during plate making, they can be clearly seen after wiping the plate; If the layout is scratched by a hard object, touching the surface of the printing plate with your hand will give a prickly feel.

02

solution
If it is due to sticking, cleaning the printing plate with a damp cloth can solve the problem.
If it is due to excessive text and images on the printing plate, and at the beginning of printing, a correction pen is usually used to correct the photocopy, but the correction pen is relatively thick. If the excess text and images exist in the contour lines or in the middle of the text, it will be difficult to use a correction pen to repair them.
The author's solution to this type of problem is to use a toothpick to stick repair paste on it for repair. During the repair, a damp cloth can be placed under the palm as a support point to fix the arm and prevent it from shaking. After repairing, quickly wipe it clean with a damp cloth.
If it is due to scratches caused by hard objects on the printing plate, the solution is to use a clean damp cloth dipped in repair paste, then dipped in a small amount of wetting powder, and gently wipe the scratched area of the printing plate a few times. When starting to print, first fill the printing plate with water and let it run for a few times before applying the ink roller. Generally, the scratches will disappear. When the scratches are severe, it is necessary to gently polish the scratched area of the printing plate with a corrosion rod, and then wipe it clean with a damp cloth.
When some or all of the printing production tasks are completed before discovering the problem of excess graphics and text, if the finished products are treated as waste, it will cause great waste, and manual processing methods can be used to remedy it.
Specifically, remove the finished product with excess graphics and text from the printing machine, let it sit for a period of time, wait for the ink to dry, and use a single-sided blade to scrape off the excess graphics and text. Pay attention to the gentle movement when scraping, as it is beneficial to scrape the paper surface without pilling. After scraping, gently wipe the scraped area with a rubber.