Color box printing plant old driver to teach you to analyze the causes of offset printing machine water bar, ink bar

Color box printing plant old driver to teach you to analyze the causes of offset printing machine water bar, ink bar

Offset printing machine in the printing process presents water, ink bar failure, for the operator is a more solid problem, especially small book printing plant. Because of the long overload work, maintenance is not proper, the phenomenon of water, ink bar is more outstanding than the high-speed machine. Now based on the old generation of color box printing plant operators for many years of operational experience, in the practical operation of the phenomenon of water, ink bar, make some brief analysis for the operator of the printing plant for reference.

Generally speaking, the offset printing machine presents water, ink bar, both due to mechanical wear and tear caused by improper conditioning. Presented after the water, ink bar should be from various aspects to find the reason, carefully analyze, identify the ink bar is still water bar. We know that the ink bar is in a certain printing surface dot or graphic present irregular or regular dark-colored line stripe, wide about 5 to 8mm, the dot expansion; water bar is in a certain printing surface dot or graphic present irregular narrowing of light-colored line stripe. Whether it is water bar or ink bar, will directly affect product quality. Therefore, the operator should understand and master the main reasons for the onset of the bar in order to deal with timely.

  1. Drum gears severe wear onset of ink bar. Machine in the process of using often have oil, paper, ink into the teeth, long time and constantly build up, presenting the top teeth phenomenon. Printing plate cylinder and rubber cylinder ask too much pressure, gear gap is too small, gears can not accurately mesh with each other, that is, in the printing onset of tremors, cylinder appearance of a large sliding friction. At this time, the printing plate may be presented with the gear pitch flat ink bar, the printing plate on the dot or graphic simple damage, reduced print resistance. 2 between the drum pressure is too large seizure of the ink bar. Many factories do not do a fine job on the machine three flat, serious impact on product quality. Especially in the operation of a long time some operators blindly increase the pressure, change the rubber blanket, plate liner is not carefully measured, imprinting significantly hear the roar. We know that, according to the normal pressure, plate cylinder and rubber cylinder tightness does not exceed 0.1 ~ 0.15mm, rubber cylinder and impression cylinder tightness does not exceed 0.15 ~ 0.2mm, if you add the liner at will paper, constitutes too much pressure, so it is easy to attack the ink bar.
  2. Ink bar onset of bucket collision. Machine imprinting cylinder on the hopper in the gripper when the instantaneous oscillation of the force is greater, then the drum is easy to attack the instantaneous speed change, and several gears next to the drum bump bolt to withstand the force is also the largest, easy to wear and tear, and overnight the onset of the ink bar. Presented by the ink bar in the printed sheet reflected in the general location from the gripper 7 to 8mm at a fixed. This situation should be replaced when the turntable and hit the bolt, change the orientation of the gears, stagger the wear of the teeth, the turntable on the spring force to loosen a little, to prevent excessive oscillation, reduce wear and tear.
  3. rubber roller sorting caused by the wrong ink bar. General 01 machine ink roller has four, and the diameter is not the same, the intention is to prevent the onset of ink bar. Such as the diameter of 81, 77, 76, 79mm of the four inking rollers, its placement from the front after the column should be 81, 77, 76, 79mm in diameter, such as in the installation of rubber rollers, sorting is not the right or pressure adjustment is not appropriate, easy to attack the ink bar. 5 between the rubber rollers or ink rollers on the printing plate pressure caused by too much ink bar. In adjusting the ink roller pressure, not only to the ink roller and plate pressure carefully adjusted, the pressure between the ink roller should also be uniform and common, such as unilateral indentation width of more than 6mm, the ink bar is often attacked on one side. Some small factories with 01 machine printing books, not often scrape the rubber roller, rubber roller is easy to aging and hardening, on the plate friction increases, in the roller gap at the gripper edge encountered a transient jump, so the gripper is easy to attack a more significant ink bar. Therefore, in adjusting the inking roller on the plate pressure, it is necessary in the case of the plate liner to meet the specifications, according to the inking roller sorting, in the ink on the plate width of the ink marks for the 5, 5, 4mm is more appropriate, and parallel at both ends.
  4. Bridge gear wear caused by the ink bar. String ink roller two bridge gear with eccentric equipment, adjust the appropriate must lock the screws, leaving a certain gap. Too tight when the onset of noise, if the smooth is not in place, coupled with dirt between the teeth, oil, will constitute a serious wear and tear of the gears, resulting in the gear mesh is prohibited, the series of ink rollers onset of vibration, the printing plate will also leave a significant ink bar.
  5. The ink bar caused by the hardening of the rubber roller aging. To the book version of the printing press, offset press operators, such as not often wash the rubber roller, ink long time accumulation in the rubber roller, coupled with the paper in the dust penetration in the rubber roller appearance, after the onset of friction on the exterior of the rubber, cracking, luminous hardening, rubber rollers ink performance decline, the onset of a significant ink bar. If the rubber roller aging is not serious, only the appearance of a layer of bright film, the rubber roller can be unloaded, with pumice powder gently rubbed appearance, completely remove the appearance of the ink skin, ink bar will disappear or reduce. If the rubber roller aging is not flexible, work between the rubber roller slipping, it is necessary to replace the rubber roller.
  6. Oscillation of the ink bar. Machine roller gap is large, in the work of any two drums between the pressure constantly in the gap at the disappearance of the entrance to the presentation. Roller in and out of the impact constitutes a source of oscillation, especially the tumbler touching the onset of oscillation, and therefore, the existence of the source of oscillation of the offset printing machine, is the main reason for the onset of oscillation bar. Machine in normal operation, these oscillation sources in an instant to destroy the uniform rotation between the drums. Once found the oscillation bar, should first find the source of oscillation, the right ring problem will become simple from the mess.
  7. Printing plate cylinder and rubber cylinder, rubber cylinder and impression cylinder between the printing pressure is too large seizure of the ink bar. Theoretically, most of the requirements of the printing plate cylinder and rubber town of Jane between the mark width of 4 ~ 6mm, rubber cylinder and impression cylinder between the mark width of 5 ~ 7mm, but the operator to adjust the center distance accurately after the amount of liner circle forbidden, found that the print is not real, and arbitrarily add the liner paper, she sometimes the rubber cloth taut is not tight, the pressure is high backward, the rubber cloth will be presented as a rubbing the same as the ink bar.
  8. Other reasons for the ink bar. Such as ink distribution is too thin, viscous small easy out of the bar, coated paper printed on the ground or netting easy out of the ink bar, dark-colored ink in the blue ink is easy out of the ink bar; liner thickness is not uniform, poor quality of the blanket is easy out of the ink bar.
  9. water bar, also known as the white bar, in the low-speed machine onset of water bar is generally due to the water roller on the plate touch pressure caused by a large, characterized by the plate gripper shiny, there is a fixed bar. Offset printing machine water supply mechanism is a cam control, water transfer in the plate cylinder gap, should be correctly adjusted to transfer the water roller control cam position and plate touch time, and choose the appropriate pressure. General machine has two by the plate water roller, only need to adjust well, only one by the plate water roller can be. According to the survey, the general use of a below, but the water roller, the operator of the machine point to the neutral position, with a pry bar to pry out the water roller, so that the water roller bracket is simple to loosen or cause deformation of the water roller, and therefore still use the top of a more appropriate to prevent the onset of the water bar.
  10. In production, we also found that the inking roller and string ink roller pressure between the lighter when the water bar will occur. This is because the pressure between the ink rollers is too light, the ink in the rubber rollers can not be passed evenly, floating on the rubber rollers. When the water and ink imbalance, because the rubber rollers on the exterior of the ink layer is thickened and caused by the ink emulsification, easy to show the water bar on the printed sheet.
  11. Water roller swing frame oscillation caused by too much water bar. Machine water roller swing frame by the cam control, machine use for a long time cam wear. In the gap at the onset of beating, water bar is more significant, mostly in the printing of 5000 or so to make the presentation of the water bar, the printing plate print resistance decreased.
  12. water roller set of poor quality, part of the uneven, water-packed roller package is not tight, loose center at both ends of the tight, uneven water supply or water is too large, are prone to gripper before the two lines of the word at the presentation of the water bar. In short, when you operate the machine presents water ink bar, must be analyzed from various aspects, step by step clarification, as long as the treatment is appropriate, will be able to get satisfied with the treatment.

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