1800AWD offset press fault

The 1800AWD offset press produced by the Yingkou Copier Factory is a pneumatic suction paper. The paper is sucked by six suction nozzles, fed into the upper and lower two feed rollers at one time, and then sent to the impression cylinder by the feed roller. Grab the paper and hold it up for transfer. The printing speed is 3,000 impressions per hour to 9,000 impressions, usually 5000 impressions per hour.
Pleated paper is the most common fault in the use of the aircraft. There are many reasons for this failure, which can be roughly divided into three categories:
1 paper is not good, such as paper is not flat, the factory time is short;
2 improper operation, such as the air flow is too large, the paper table is not neat paper stack;
3 The machine's own faults, such as individual nozzle damage, suction nozzle swing not in place, sub-sheets block paper, air flow is not cut off in time, catch paper pressure is uneven, the printing pressure is too large or imbalance, grab the paper shaft Lack of coordination with the lever assembly.
Wrinkles caused by poor paper, in general, relatively small folds, often in the second half of the paper, when the cause of the failure can be used to replace printing paper. Paper creases caused by suction nozzles or paper breaks, the leading edge of the paper is often accompanied by traces of tearing or tearing of the paper edge. Air flow cut-off does not promptly cause the printing paper to cause an attack. The area of ​​pleats is generally relatively large. When inspection is performed using the manual feed operation mode, the suction nozzle feeds the paper between the upper and lower feed rollers and the upper feed roller has When pressed down, the suction nozzle still has a slight suction force on the paper (normally, the pressure on the upper paper feed roller has not been pressed, and the suction nozzle should release the paper). The pleats of the printing paper caused by the paper picking are more regular, and the pleats tend to move towards the paper with small pressure. The size of the pleats can also reflect the degree of pressure reduction of the picking paper. Paper pleats caused by improper operation often have discontinuities. The following describes an example of how to remove pleats from printed paper through an example.
Symptoms: Printing paper creaks continuously, and pleats are more severe. Inspection and maintenance: According to the fault phenomenon, it is initially judged as a machine failure. For the sake of accuracy, first of all, several kinds of papers are tested and printed. All of them are similar. It is not a matter of paper. The suction and air blow control knobs do not work. It can be concluded that this is a machine malfunction. Place the machine in the manual feed state. Turn the handwheel by hand to observe that the suction nozzle sucks and swings normally, and the airflow is cut off in time. The paper is divided well, and the upper paper feed roller can timely feed the paper under the paper catcher of the embossing roller, so that the paper catch part is transferred to the exposed position of the back of the machine, and the machine safety cover will be lifted. The printing paper is pulled out from the respective pick-up papers, and the test is to determine whether the pick-up pressure is the same or not. It is found that there is a slightly lower pressure on the pick-up sheet, the sheet is unloaded, and the arc of the sheet is slightly increased by a pliers, and the machine is set in the machine. After that, the pressure of the paper catcher is basically balanced, but the pleat failure still exists. It is suspected that the overall pressure of the paper catcher is insufficient. Adjusting the pressure regulating screw on the boring bar assembly and increasing the pressure of paper catching still does not work. Then inspect the lever assembly and the pick-up shaft, first loosen the pressure-regulating bolts on the lever assembly, release the pressure on the pick-up blade, and then grasp the pick-up blade by hand to forcefully move back and forth, and find that there is a defect between the pick-up shaft and the lever assembly. The phenomenon of movement, the fixed pin (spring pin) between them was punched out with a diameter of 3mm steel, it was found that the pin was broken vertically, and the fault was removed after the replacement. The reason for this failure is that after the pin is broken, the degree of rigidity is reduced, and the lever assembly cannot transmit sufficient torque to the pick-up shaft through the lever assembly, thus catching the sheet of paper so that there is insufficient grasping force, resulting in pleated printing paper. malfunction.
There are many reasons for the pleats of printed paper, but as long as they are diligent in practice and good at summing up, they can grasp their laws, take detours when dealing with failures, and get twice the result with half the effort.