Analysis of the misfeed failure of the hottest j41

Failure analysis of uneven paper delivery of j4103 offset press

we have been engaged in printing for many years and found that j4103 offset press is a very common model, especially in small and medium-sized printing plants, and some manufacturers have more than one. We have a lot of contact with j4103 offset press. Its 500 kg load and uneven paper delivery bring a lot of inconvenience to the post printing process, which often troubles the workers and technicians who operate the machine. The uneven paper receiving of the first side affects the whole paper and printing of the second side; Uneven paper delivery on the second side will affect the counting, binding and folding, which greatly affects the work efficiency. Moreover, due to uneven paper delivery, the scrap rate is also increased. Combined with the printing machinery and technology, I make a specific analysis of the failure of uneven paper delivery for the reference of colleagues

first, the function of the electrostatic eliminator is not good, resulting in uneven paper delivery

as we all know, paper often carries static electricity. The function of electrostatic eliminator is to eliminate electrification or reduce the amount of electrification of paper. However, due to the change of temperature and humidity (especially in spring and Autumn), the paper is particularly easy to be charged. Its chemical structure formula is kal2[(al, SI) si3o10] (OH) 2O, which requires a good power dissipation effect of the electrostatic eliminator. Therefore, we should always keep the discharge rod and discharge needle clean, and often remove paper dust and oil stains. When it is found that the electrostatic eliminator does not work, first check whether the power indicator is on, whether the power plug is too loose, whether the power start on the electrostatic eliminator is turned on, and whether the fuse is intact. When all the above is normal, but the static electricity is still serious, conditional printing plants can install spray to increase the relative humidity of the workshop, which is more effective in eliminating static electricity

second, the paper itself is deformed or too thin and thick, resulting in uneven delivery

the paper leaves the factory from the paper mill. Through transportation and long-term storage, the paper is deformed due to the frequent changes in the surrounding climate and the difference in humidity between regions. Therefore, the hysteresis effect of paper should be used to adjust the humidity of paper

the paper cutting error should not be too large, generally not more than ± 2mm. It is required that the four corners should be close to 90 ° as far as possible. The curled edges should be flattened by hand to ensure flat clothing. According to the actual situation, fill the paper receiving platform with boards, paper balls and other methods to keep the paper receiving stack flat. Sometimes the paper is too thin, causing the paper to be rolled forward when it is received and discharged. At this time, two thin and hard materials with a width of 3 ~ 5cm can be wrapped on the connecting shaft connecting the wallboards on both sides above the paper receiving table, and its length should be lower than the paper receiving row, which will not affect the normal operation of the paper receiving row, so as to buffer the paper. If the paper is too thick and the paper rolls down, it will drill under the front trimming board. At this time, Panasonic exchange servo machine can put two rubber bands with an inner diameter of 15mm and an outer diameter of 40 mm on the two trimming boards on the side of the front trimming board, which are about 50 ~ 100 mm higher than the paper stack, and can be adjusted up and down according to the specific situation

third, the paper placing time on the paper receiving platform is not coordinated with the side trimming board and the back trimming board, resulting in uneven paper receiving

the function of side trimming board and back trimming board is to align the left and right, front and back of the printed sheets after stamping. The position of the paper on the paper receiving table should be in the middle of the left and right side trimmings. The distance between the left and right side trimmings and the side of the paper is the same. You can loosen the translation adjusting screw of the side trimmings for adjustment. When the paper is placed on the paper suction table, the action of the side trimming board should be to start to translate backward. Too fast or too slow translation will affect the tidiness of the paper. It can be adjusted by the translation and rotation cam of the side trimming board inside the chain wheel. Loosen the three fastening screws, turn the translation cam of the side trimmer, and make the translation time of the left and right side trimmers synchronized with the matching time of the paper

fourth, the air volume on the suction reducer is too large, too small or inconsistent, which will cause uneven paper delivery

the suction reducer, or paper receiving buffer, is composed of buffer, regulating air valve, air pipe, etc. its function is to reduce the conveying speed of paper when it reaches the paper receiving table, reduce the impulse, and prevent the printing sheet from floating, so as to obtain a good effect of neat paper receiving

air leakage of the suction cover is a common fault, and the air leakage suction cover should be sealed firmly with adhesive in time. The overall size of the suction volume can be adjusted by adjusting the suction volume of the air pump. Individual adjustments can be made to individual suction inconsistencies, which can be solved by adjusting the on-off valve. The position of the suction hole on the suction seat frame should be aligned with the suction hole on the suction pipe. The suction port on the suction seat frame should keep a certain distance from the rotating suction cover. It is required not to be too low. If the suction is too low, it will be weakened or ineffective. It is appropriate that the rotating suction cover can rotate on the suction port without touching the inner wall of the suction cover, which is generally kept at about 1mm. Adjust by loosening the fastening screw on the suction seat frame

fifth, the handover time and bite force between the paper receiving chain bite and the roller bite will also affect the uneven paper receiving

① biting force adjustment support spring can change the total biting force of the biting row, and the small support spring on each bite can adjust the biting force individually

② adjust the handover time of chain teeth during handover, as shown in Figure 1: loosen the screw 4 and move the boss 3 to change the opening and closing time of chain teeth, so that the printing sheet can be received smoothly

sixth, the paper placing time on the paper receiving platform is too fast or too slow, resulting in uneven paper receiving

the adjustment of the paper discharge time of the paper receiving teeth is shown in Figure 2: the paper receiving teeth reach the paper receiving table, the teeth open after being impacted by the boss, and the printing sheet falls from the teeth. The paper discharge time can be adjusted by adjusting the position of the latch 1. The positioning plate 4 is equipped with 7 holes, and the positioning holes at different positions make the shaft 2 rotate at different angles, so as to change the working position of the boss 3, that is, the paper discharge time is changed, turn clockwise, and the paper discharge is slow, Otherwise, it is fast

in addition, you will see that the paper dropping device of the mine Mirs intelligent packaging mirror made of Kos creative clone polycarbonate breaks down, or the printing pressure is too heavy or uneven, and the printed paper is much different from the position of the paper receiving platform, which will also affect the uneven paper receiving