Gravure printing machine common eight kinds of mechanical failure and elimination methods

Published on:



Gravure printing machine common eight kinds of mechanical failure and elimination methods

The structure of gravure printing machine is more complex and the maintenance is professional. In addition to the normal operation and maintenance, the adjustment and repair of the equipment should be entrusted to professional technicians. When a fault occurs the technician should be able to carry out a simple analysis and take appropriate measures to ensure personal safety, product quality and protection of corporate property.

一. Unwinder A/B reel barging failure rate is high

① need to check whether the A/B reel is synchronized, the transmission parts (synchronous belt) is effective transmission; ② measure the actual material volume diameter, and the system self-test comparison, whether the volume diameter is consistent; ③ barge arm and volume machine flip barge position is normal. Whether the counter-eye and reflective eye are working normally, and whether the detection position is correct; ④ whether the barge cutter and pressure roller action is smooth and consistent, whether there is over- or lagging phenomenon, whether there is water vapor in the air pipe or the air pressure is too low, thus affecting the normal work of the cylinder; ⑤ whether the material roll is slipping, affecting the eye detection (the problem will directly lead to large fluctuations in finishing tension and poor color accuracy). Check whether the power side and operation side operation thimble is not fixed tight material roll when installing the material roll; ⑥The surface of the collector ring oxidation or carbon brush wear serious, electrical signal output, input weak, affect the components energized action and feedback. Need to be processed accordingly, so that the component energized, contact normal, maintenance requires power-off operation; ⑦ adhesive tape viscosity is not enough, need to replace the adhesive tape.

二、Traction device failure

(1) Steel roller traction is not synchronized

①Check whether the rubber roller is pressed together with the steel roller and whether the rubber layer of the rubber roller is aging; ②Check whether the pressed together reaches the specified air pressure and whether there is air leakage or obstruction in the air circuit; ③Check whether the speed of the steel roller is synchronized with the speed of the equipment and whether the transmission parts (synchronous belt) effectively transmit the power; ④Check whether the motor encoder works normally (traction is not synchronized will directly affect the tension and color register accuracy).

(2) Poor cooling effect

① whether the cooling water temperature is kept at 20~25℃, or using cooling water 5~15℃; ② whether the water quantity meets the requirements and there is enough cooling water circulation; ③ whether the scale is generated inside the cooling roller because of long-term use, blocking the inside of the cooling roller, which can be cleaned by using high-pressure cleaning pump, using acidic solution for high-pressure dissolving cleaning, and keeping a good cooling water pipe open.

三、Failure of shaftless loading mechanism

(1) Gearbox heating

① need to timely check the lubricant situation in the gear box, lubricant can effectively maintain the lubrication of transmission parts in the gear box, cooling parts failure; ② when the gear box is hot and accompanied by increased noise of the gear box, it may be the gear box internal transmission parts wear or damage, need to stop and check in time; ③ check whether there is ink or solvent from the gear box cone top rod flow into the gear box, resulting in bearing damage or other transmission parts damage.

(2) Poor accuracy of horizontal registration of the plate axis

① power side cone plug structure for the cylinder cone top form, whether the manual valve rotation in the cylinder exit (air intake) state. Whether the cone plug and the plate cylinder fit well, whether there is slippage gap, check the cone plug and the plate cylinder fit, whether there are scratches or heat; ② whether the permanent magnet low-speed motor of the plate shaft transverse automatic is working normally, whether there are abnormalities; ③ can be manually set to test the action, but also through the manual set to adjust the set back to automatic after adjusting the set, observe the changes in the set; ④ printing plate or loading plate precision reasons.

 四、Imprinting mechanism failure

(1) Poor ink transfer effect

①Stamping force. Check whether the actual embossing force is consistent with the pressure value of the regulating valve, the cylinder bore to calculate the corresponding pressure gauge value corresponding to the number of cylinder output pressure. If inconsistent, you need to check the pneumatic components, the main air source air pressure and whether there is mechanical resistance obstruction and other factors; ② poor quality of the embossing cylinder and surface adhesion impurities caused by the cylinder should be replaced.

(2) The problem of color registration accuracy

①The impression cylinder is a passive component, the cylinder and the printing plate should be in a synchronized state when pressed together. If not synchronized, you need to check whether the rolling bearing is rotating flexibly and whether there is a jamming phenomenon; ② check whether the impression cylinder action is normal when you start printing; ③ check whether the impression cylinder and the printing plate cylinder fit well.

 五、The problem of scraper mechanism

When there is poor scraping ink effect, you can check and troubleshoot from the following aspects: ① confirm the scraper mechanism related to swing parts screws, bolts, fixed hand wheel, handle, scraper clip are locked labor, tighten; ② check the scraper lift, front and rear, swing and other frequently operated parts of the screw, worm gear worm gear vice whether there is wear and tear, whether the gap is generated; ③ whether there is transmission, transmission parts jammed, work inflexible phenomenon. Sliding bearings, transmission parts, rotating parts, etc. whether there is sufficient lubrication; ④ scraper is working in the state of no ink. Ink in the scraper blade and the plate cylinder between the role of lubricant, but the scraper blade and the plate cylinder rigid contact and no ink state, will cause the scraper blade friction, heat, but also on the plate cylinder damage; ⑤ scraper swing is smooth. Scraper swing is through the gear box below the output shaft to transfer the scraper swing power. The position is the conversion of circular motion into linear motion, the part is easy to be ignored, need to pay special attention to keep the part flexible. Equipment use for a long time, very easy to grease aging or dust accumulation caused by mechanical resistance.

 六、Ink pad lift failure

The ink plate lifting is through the turbo worm vice with the rack and pinion to achieve the purpose of lifting and self-locking. Usually the failure of the lifting device is caused by insufficient lubrication, high lifting resistance, power side and operation side lifting is not synchronized, etc. The flexibility of the transmission parts can be maintained by lubricating or cleaning the dust and ink on the transmission parts. The part must be installed to keep both ends at the same horizontal height.

 七、Upper ink roller failure

①The upper ink roller rotation failure. If the motor is overheated, noisy, the upper ink roller shaking (exclude the upper ink roller rubber quality problems, the upper ink roller itself jumping problems), you can start from the transmission parts to check and repair.

②The upper ink roller pressure together failure. The upper ink roller pressure / away from the state, depending on the action of the cylinder, the working height of the upper ink roller can adjust the limit nut on the cylinder to meet. If there is a problem with this part, you need to check whether there is obstruction in the air circuit, whether the air pressure is in accordance with the requirements, whether the limit is correct, and whether the moving parts are flexible.

③The upper ink roller speed failure. The transmission ratio in the upper ink roller mechanism is a fixed value. The speed is adjusted by potentiometer, and the potentiometer control source is inverter, which controls the motor frequency to meet the required speed. Can understand the relevant electrical information, according to the electrical instructions to repair.

 八、Longitudinal deflection mechanism failure

The longitudinal correction is driven by the permanent magnet low-speed motor, and the signal is transmitted to the encoder of the color register system to ensure the register accuracy by mutual feedback. When the longitudinal register accuracy is poor (the premise is not caused by the register system) and the correction response is inflexible, it can be checked from the following aspects: ① check whether the register encoder is faulty; ② check whether the low-speed permanent magnet motor is faulty; ③ check whether the film route is normal; ④ check whether the worm gear vice is working flexibly and whether there is jamming and large resistance, etc. Whether the ball screw work is flexible and effective, whether the left and right sides of the ball screw are in the horizontal state, and whether there is any obvious obstruction or action not smooth when the motor drives both ends of the screw to rise or fall at the same time. The worm gear vice should pay attention to maintenance and lubrication; ⑤ The color register system can be selected to manual position, adjusted to color register qualified and then select automatic color register, watch the color register deviation and longitudinal correction work.