Common faults and elimination of Heidelberg offset presses
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Fault 1: The paper arrives at the front gauge and the entire machine is shut down.
Analysis: This fault is mainly caused by the paper not getting good and the light hole not being adjusted.
Cause of failure 1: The paper is too early or too late.
Remedy: Jog the machine to move the paper to the front gauge. When viewing the front gauge return position and dropping to the lowest point, the distance between the paper and the front gauge is 4~5mm. If it is less than 5mm, the paper is too slow; otherwise, the paper is too fast. The two ¢13mm nuts of the operating surface can be loosened and adjusted to the standard position by means of the flange.
Cause 2: If the paper is not in place, it may be that the light control head of the front gauge is malfunctioning.
Remedy: After jogging the machine to the front gauge to the positioning position, put a square paper on the front gauge and gently push it to the front gauge. At this time, the two gauges of the light control head are placed at the front gauge. The photoelectric display light should be on. If one does not light, it means that one side is ahead, causing the illusion that it has not arrived. Turn the adjusting screw clockwise until the indicator light is on, then turn it into 1~2 turns.
Cause 3: If the two photoelectric display lights are not bright or dark when they are lit, there may be impurities such as paper hair on the light eye, which may cause photoelectric detection errors.
Remedy: Wipe clean with a soft cloth dipped in alcohol.
Cause 4: The swinging teeth are too small. You can click the machine to view it. When you find that the paper is bounced back when you swing the hem to the quick crepe paper, it is judged to be caused by the swinging teeth.
Remedy: Jog the machine to the position of the paper feeding paper to the paper feeding table. At this time, the 90° right angle gauge can be used to measure the position of the dental pad and the paperboard at 90°, and the shank with a mm13mm socket wrench Tooth nut (operating surface), use a 1mm screw to insert into the teeth, and then use a 3mm hex wrench to adjust the adjusting nut, the handle is slightly resisted when pulled out.
Cause 5: The paper is skewed or the paper is burred, causing downtime.
Remedy: At this time, the Feida and the paper feed lever can be adjusted to make the two sides fast and slow.
Fault 2: The paper side gauge is not in place
Cause 1: Because the second mobile phone is used for a long time, especially the wear of the pull bar is serious, causing the pull plate to withstand the lower plate and the pull ball can not touch the pull bar.
Remedy: At this time, loosen the two ¢5mm fastening nuts on the puller strip, remove the puller strip, and use 0.1mm steel sheet (depending on the degree of wear) to make the shape of the pull tab And fasten it under the original brace, add the right amount of oil to tighten, and the effect is good.
Cause 2: The traction plate is up and down on the mountain and is seriously worn, causing the paper to rise and fall not to be crisp, and it is easy to cause the paper to be out of place.
Remedy: The pull-down gauge plate can be removed, and the thickness of the original wear is 1mm, and it can be installed in the original position.
Cause 3: The side gauge tension spring pressure is too small.
Remedy: Tighten clockwise.
Cause 4: The eccentricity of the pull gauge ball is too high.
Remedy: Turn to adjust to fit.
Cause 5: When printing whiteboard paper, the pressure of 4 brush wheels is too heavy.
Remedy: Adjust the light or move it back to the appropriate position.
Fault 3: CPC shows a large amount of ink, but the actual amount of ink is relatively small.
Cause 1: The ink fountain film is used for a long time, and the leaked ink is agglomerated under the ink fountain sheet, causing the ink discharge amount to decrease.
Remedy: Clean the ink on the cylinder eccentric (32 total), and replace the dirty sponge strip with a new ink fountain (the ink fountain has a service life of 36 hours).
Cause 2: The motor screw that controls the amount of ink is accumulated on the screw, which makes the screw rotation inflexible or even stuck, resulting in no ink or uneven ink output.
Remedy: Disassemble the 32 blocks under the ink fountain (note: do not lose the hollow sleeve on the fastening screw), use the needle to remove the ink on the screw, and remove all the accumulated ink, and move the CPC to make each motor The flexibility can be achieved from the minimum amount of ink to the highest amount of ink, and the tank is filled with butter, which can maintain good ink discharge for a long time, and the effect is very good.
Fault 4: The ink transfer roller is not good.
Cause 1: Due to long-term use of the transfer roller, the surface is aged, the ink transfer performance is degraded, and the rubber on the surface of the ink roller is cracked or crystallized.
Remedy: If surface crystallization occurs, it can be repeatedly wiped with gasoline pumice powder to improve surface adsorption performance. The surface aging caused by cracks can only be replaced by the same size ink roller.
Cause 2: When replacing the transfer roller, the size of the machine is not enough, which may cause the size of the replaced ink roller to be too large or too small. If the ink fountain roller is continuously slipped during the adjustment, the corner angle is sharply increased, which is caused by the large size of the ink roller, and the ink transfer roller does not disengage from the ink fountain roller when the ink is transferred to the ink roller.
Remedy: If this situation is found, it should be stopped decisively and replaced with the standard size ink roller. Generally, the diameter error of the ink roller should be controlled within ±0.5mm.
Cause 3: Due to long-term use, the ink of the ink fountain roller is greatly vibrated when the ink is transferred. In addition, improper adjustment of the ink transfer roller causes the hollow pins at both ends of the ink transfer roller to bend, causing the ends of the ink roller to be different. Generally, when the transfer roller is in operation, one end is in good contact with the ink fountain roller, and the other end is not in contact with or in contact with the transfer roller. If the pressure of the end and the ink fountain roller is increased, the slippage of the entire transfer roller will occur, causing the vibration of the machine to be increased and the ink to be darker and the printing cannot be performed at all.
Remedy: The shells on both sides can be removed, the back of the two ends of the ink fountain can be removed, and the hollow pins at both ends of the transfer roller (¢ 8 mm) can be taken out and replaced with new ones.
Note: A hollow pin with a diameter of 6mm should be inserted into the new ¢8mm hollow pin to ensure that it does not deform for a long time.
Fault reason 4: The transfer roller controls the gas valve fixing screw to break, resulting in no ink transfer or more wear on the back of the transfer roller, so that the transfer roller will also hit the ink fountain roller when the ink stops.
Remedy: Open the cover on the side of the machine operating surface and check whether the valve fixing screw is intact. If it breaks or falls off, reinstall it. After installation, press the transfer roller switch to check whether the valve is working properly. If it is not normal, it should be removed and repaired. If the backing is more serious, loosen the 3mm head screw on the back of the mountain, adjust it to the proper position, and then lock the head screw.
Fault 5: The printing plate is easy to paste and greasy when printing
Cause 1: The ink additive or varnish in the ink fountain is added too much, so that the ink is too thin, and the mouth of the mouth is greasy.
Remedy: First increase the amount of water in the entire layout, or clear it. Shut down again, scrub with moisturizing powder, hundreds of sheets before printing, and then repeated. Considering that Heidelberg high-speed machine has only one version of the rubber water roller, its water-carrying capacity and cleaning ability have no effect on the water roller with water-containing velvet sleeve. At this time, it should be printed with original ink, and special products need to be added with auxiliary materials. Be sure to be moderate. When it is found that the oil is dirty due to too thin ink, the original ink should be added to the ink fountain or the ink should be replaced.
Cause 2: The pressure of the plate water roller and the water roller are biased or light.
Remedy: If the pressure is heavy, the water on the plate water roller will be squeezed out by the water roller to cause the paste; and the pressure is too light, the ink on the ink roller can not be removed when it is printed. Observed below the water bucket, you can see traces of ink on the water roller, which also caused the paste. At this time, the metering roller can be removed, and the pressure is re-flattened with a 0.1 mm steel sheet. The width of the ink bar between the plate water roller and the water roller can also be checked. Generally, it is preferably adjusted to 3 to 4 mm.
Cause 3: The pressure between the metering roller and the plate water roller is too heavy or too light.
Remedy: If the pressure is too heavy, then when the machine is running, when the water roller is lowered, the water roller seat valve can be clearly seen to jump. When you see this phenomenon, you should stop immediately and re-adjust the pressure. Do not print it too much to avoid damage to the valve and damage to the water roller bearing and needle roller bearing. Generally, a white paper can be inserted between the metering roller and the water roller, and the water roller seat valve can be manually dropped. After lifting, the paper strip is taken out to view the width of the ink bar, and the width is adjusted to 5 to 6 mm.
Cause 4: The pressure between the plate roller and the plate is too heavy or too light.
Remedy: Excessive pressure between the plate water roller and the plate will also cause the water roller seat valve to jump. The specific adjustments are screaming and screaming, 6mm is appropriate. Each time you replace the new version of the water roller, the pressure should be re-adjusted, the pressure of the new water roller can be adjusted lightly, the water roller can be slightly increased after a long time, However, the water roller seat valve does not jump to the maximum.
Cause 5: It is caused by the unadjusted roller.
Remedy: This situation is mostly caused by the pressure of the latter two ink-receiving rollers being light, but the pressure is too large, and the hydrophilic layer of the printing plate is easily destroyed prematurely, and the printing plate is bright and the oil is dirty. The machine can be stopped to the appropriate position, manually lowered and pressed by the plate roller, and the width of the ink bar of the four ink rollers is observed. Generally, it is suitable to adjust to 3 to 5 mm.
Cause 6: The water from the bucket roller is uneven or the hose roller fastening screw is loose or broken.
Remedy: If the surface of the bucket roller is aging, replace it with a new bucket roller. In the usual cleaning of the water bucket roller, the rag that is clamped in will also cause partial depression, resulting in a large amount of water in the area, which increases the pressure between the entire metering roller and the water bucket roller, resulting in edge paste. If the injury is light, use a reducing agent to wipe it back. If it is not well adjusted, only replace the new water roller. However, if the metering roller and the plate water roller fastening screw are loose or broken, the paste or the plate may be caused by poor water supply, and special attention should be paid during the adjustment process.
Cause 7: The water tank is not working properly. Remedy:
(1) The water tank refrigeration device is damaged, causing the water temperature to be too high, so that the alcohol volatilization rate is too fast, the surface tension of the water is decreased, the dampening solution cleaning capacity is insufficient, resulting in a paste, so the refrigeration device is essential. Generally, the water temperature should be controlled between 3 and 5 °C.
(2) The alcohol concentration is too high or too low. Generally, it should be adjusted according to the amount of ink printed. The alcohol concentration should be controlled between 15% and 25%, and should not exceed 30%. Otherwise, the hydrophilic layer of the printing plate will be damaged due to excessive alcohol concentration.
Fault 6: Imprinted ink color is uneven
Cause 1: This group caused ink emulsification due to large water and ink, and deinked.
Remedy: Check whether the ink color on the ink roller is dark, whether the particles are coarse, whether there is waterless ink in the ink fountain tank or whether the ink is emulsified; if the ink is emulsified seriously, use the shovel method to wash the ink roller and replace the ink in the ink fountain tank. The amount of water should be strictly controlled when printing ink.
Cause 2: The pressure between the platen roller and the squeegee roller is light or not leaning, causing the ink to accumulate on the ink roller from time to time.
Remedy: The ink roller can be removed, and the pressure between the two rollers is re-flated with a 0.1 mm steel sheet.
Cause 3: The intermediate roller is not properly adjusted.
Remedy: The pressure between the intermediate roller and the plate water roller or the first roller roller is too light or even in place, which will cause the ink to accumulate in the place. Stop the machine and open the rear cover with 0.1mm. The steel sheet is equal to the pressure between the intermediate roller and the water roller and the ink roller. Pay attention to the flat pressure when the hand feels when pulling out, generally there is a little resistance when pulling out. If the intermediate roller and the ink roller are too heavy, it will also cause extrusion of the ink, especially when printing gold or silver ink.
In addition, the intermediate roller does not collide or even bite and does not rotate, which may cause the ink to accumulate on the intermediate roller. It can be removed or clicked on the machine for observation. Generally caused by bearing damage or fueling is not timely.
Fault 7: Printed image on dirty
Cause 1: The pressure of one of the ink roller and the ink roller is light, causing the unilateral or the entire layout to be darker when the printer is stopped after printing, and it is normal after printing hundreds of sheets.
Remedy: Re-adjust the pressure to the right.
Cause 2: The momentum of the ink roller is too small or does not cause the surface of the printed product to be a deep and light (longitudinal). Sometimes the position of the dark color corresponds to the position of the motor.
Remedy: If the amount of ink is too small, the drive surface cover can be removed (just loosen the two ¢19mm nuts), and jog the machine to the highest position of the ejector pin to release ¢ The 19mm fastening nut can increase the amount of ink. The amount of ink can be adjusted according to the disparity between the product surface and the amount of ink. The amount of ink with a large amount of ink can be adjusted larger, but it should be noted that the ink accumulated at both ends of the ink roller should be cleaned up when the amount of ink is suddenly increased. Anti-seize. The maximum ink quantity of the Heidelberg high speed machine can be adjusted to 35mm. If it is found that the ink roller does not work, it is likely that the rocker arm on the top of the ink roller is bitten or the other ink is partially bitten. It needs to be carefully checked and then printed.
Cause 3: The fastening nut of the plate roller is not locked.
Remedy: The general performance is that the two sides of the network cable are different in depth, sometimes accompanied by a slight network cable overlap (double shadow). In the normal startup state, it can be seen that the roller core of the ink roller is moving in series, and it needs to be fastened, or the roller core may not be pushed into place. The roller core should be flush with the seat, and the symptoms can be eliminated by generally adjusting to the normal working position.