Computer direct plate-making technology is another major technological revolution in the printing industry after laser phototypesetting technology. It is an automatic production system integrating precision machinery and optical technology, electronic technology, color digital image technology, computer and software technology, new printing plate and material technology, automation technology and network technology.
The application of CTP plate-making technology has greatly shortened the pre-press plate-making time, and reduced the registration error caused by manual imposition and printing. Its dot reproducibility is good, and the ink and ink balance can be quickly reached after the printing plate is set on the machine, but in actual application operations, many practical problems will also arise.
Failure caused by unstable working environment of CTP system
The working environment of the CTP system requires a temperature of 23 ± 2 ° C and a relative humidity of 50 ± 10%. This requires the CTP working environment to be equipped with an independent air conditioning system and a pure evaporative humidifier with white powder removal function. After the CTP plate is taken out from the warehouse, it needs to be left in the working environment for about 24 hours before it can be used.
If the temperature is too low, the rotating motor of the CTP plate-making machine will be damaged. In winter, the optical mirror surface will encounter condensed water mist, which will cause the dots to become virtual and uneven, and the printing resistance will decrease. If the temperature is too high, the laser head of the CTP platesetter will accelerate aging. If the temperature of the developing solution of the processor is too high, the condenser of the processor will be frequently started, so that the developing solution is easily oxidized, which will cause the CTP system to alarm or shut down in severe cases.
If the humidity is too low, it will breed dust. If the CTP platemaking machine is not dustproof, the dust will cause the optical mirror surface to be contaminated, and it is also easy to generate static electricity and damage the mainboard circuit of the platemaking machine. If the humidity is too high, the optical mirror surface will form water mist, which makes the dots become false, and the printing resistance decreases. In severe cases, it will cause the destruction of the OC layer of the CTP plate, the dots will shrink and the value will be unstable.
Common failures in mechanical movement of CTP plate-making machine
During the manipulator's gripping and advancing strokes, there will be a phenomenon of half-cutting. After the plastic suction nozzle sucks the plate, there is a movement of separating the interleaf liner with a few shakes. If the plastic nozzle is aging, the suction power is weakened, and it is easy to drop out when shaking. At this time, it is necessary to check whether the plastic nozzle is leaking due to cracks or aging. If it is damaged, it needs to be replaced in time.
When the platform enters the version, there will be slanted version, positioning failure or version reversion. At this time, you need to check whether the rubber of the universal wheel on the walking platform is seriously worn, whether the height of the universal wheel is moderate, and the positioning pin on the platform is black Check whether there is any missing cap and whether the plate is smooth, so as to eliminate the fault.
When the platform is adjusted up and down, sometimes the sensor will not sense the specified plate box. At this time, check whether the gas spring of the hydraulic rod under the platform is damaged.
Common faults in the exposure process of CTP platesetter
The core content of the plate is shifted. When this problem occurs, it is necessary to check whether the rubber of the universal wheel is seriously worn, whether the pressing speed parameter of the platen roller is correct, whether the speed of the rear positioning wheel is too fast, causing rebound, whether the parameter setting of the rotating speed of the positioning wheel is correct, and whether the gripping distance of the mechanical arm is appropriate .
The grating pulse is unstable. This problem usually occurs because the optical mirror surface is contaminated with dust, and it is necessary to wipe the optical mirror surface with professional lens cleaning paper.
The rotation motor cannot be locked at the set rotation speed. If this problem occurs, please ask professional maintenance personnel to use the oscilloscope to detect and adjust the red laser waveform, and repair the rotating motor and motor drive board.
The graphics on the printing plate are partially lost or severely misaligned. Such problems need to be thoroughly investigated: check the power supply stability, network transmission stability, whether the main board component of the plate-making machine is loose, whether the laser head is working properly, etc.
Common picture and text quality problems of CTP printing plate
The outlet level is lost and deformed seriously. For different brand versions, regular inspection and adjustment of the linearization curve of the plate material and the printing anti-compensation curve are required. The pattern in the D or E circle on the AGFA digital control strip is required to melt into one piece with the back view. If A or B or C are compatible with the background, it means overexposure. You need to reduce the exposure value or filter value. If F is miscible with the background, it means underexposure, and the exposure value or filter value needs to be increased. In the end, 1% of the outlets are not lost, and 98% of the outlets are not lost.
Relatively fixed "bee claw" scratches. This kind of scratch is different from the scratches caused by carelessly hurting the plate in the plate-making operation. It has the characteristics of being curved, dense, disordered, short, fixed in relative position and under the emulsion coating, like "hook" "The traces are mostly produced in the non-graphic area of ​​the middle edge of the short edge of the CTP printing plate. Through comparative experimental research, the author found that the root cause of the "bee-claw-like" scratches is that there may be "bee-claw-like" fine scratches in the surface treatment of the aluminum plate. After coating the photosensitive emulsion layer, no potential failures can be found. Quality issues. Only when the printing factory finishes printing the plate, the scratch will "surface" in the non-graphic blank area. Because it cannot be avoided in advance, it can only be cleaned in advance with the cleaning paste in the mutual inspection of the layout.
The increase in national environmental protection efforts will definitely lead the development of CTP plate-making technology towards low-consumption, low-emissions, and low-pollution CTP plate-making. It is expected that the CTP-free process will be promoted and popularized in newspaper printing as soon as possible.
(The author is Xinhua Newspaper Media Group)
When the dog wears the collar, be careful not to be too tight, because if the collar is too tight when running and excited suddenly, it will cause damage to the dog. A suitable Pet Cooling Collar should be worn by the dog, and there should be room for the owner to put two fingers . As the dog gets older, the lung function will become weaker and weaker, and the chest-back leash is a good choice for older dogs. If the dog suddenly leans over something during a walk, it is likely to sniff or pick up such a thing. At this time, the owner should tighten the leash and shout the dog's name to let the dog Shift your attention from that thing to the owner. When the dog's attention is shifted from the ground to the owner, just like when you are just learning to walk, remember to keep the dog on your left side, and then give him some food as a reward. The owner should know that only by establishing a good relationship of trust with the dog can it be possible for the dog to obey your commands when there is a problem with the walk.We are a supplier and manufacturer of Leash For Dogs,Pet Cooling Collar in China, providing low-cost,Walking Pet Harness , etc.
Pet Collars And Leashes,Leash For Dogs,Pet Cooling Collar,Walking Pet Harness
Mianyang Crossing Cross-Border E-Commerce Co., Ltd. , https://www.wycypets.com