The Causes and Elimination of the Ink Stick in Optical Disc Printing

The ink in the horizontal stripe of the print layout is significantly darker than the ink in other areas. The reason for the generation of the ink and the elimination method is as follows:
1, the brake bar caused by the ink bar. When the contact pressure between the rubber roller and the brake bar is too large, then during the operation of the machine, when the ink roller and the brake bar come into contact with each other, impact wear occurs. In this regard, the contact pressure between the rubber roller and the printing plate should be adjusted to maintain uniformity. With moderate contact conditions and elimination of excessive resistance, ink bars can be eliminated. When the brake shoe wears badly, replace the front end with a section of about 40 mm.

2, the roller caused by the roller. When the contact pressure between the rubber roller and the printing plate is too large, when the ink roller contacts with the printing plate during the operation of the machine, it is easy to generate shock and cause tremor, so that the increase of the frictional force causes a streaky streak. If several stencil-type ink fountain rollers are under too much pressure, the density of the bar marks will be greater. In this regard, by adjusting the contact pressure between the rubber roller and the printing plate to maintain uniform and moderate contact conditions, eliminating the excess resistance, the ink bar can be better eliminated.

3, roller gear wear, gear clearance is too large or there is a foreign matter accumulation between gears. When the roller gear wears, gaps or adhesion of foreign matter in the teeth, during the operation of the machine, the roller gears can not be meshed with each other accurately, so that the line speed between the rollers is not consistent enough. In addition, the backlash is too large, the drum is also prone to tremor jitter, the formation of print marks, so that the printed layout of the track and the gear pitch similar to the ink marks. There is a foreign body obstacle in the backlash, and it is easy to cause the drum to tremble due to the "top gear" phenomenon, so that the horizontal layout of the print product forms a strip-like ink stick. In this regard, the distance between the rollers should be reduced by re-adjusting the center-to-center distance between the rollers; new gears should be replaced for those gears that are worn out badly; the adhesion of foreign materials to the teeth should be cleaned before the effect of eliminating ink bars can be achieved.

4, roller bearings have a greater wear and tear. When the roller shaft head lacks oil running or the machine wears naturally for a long time, the gap between the roller shaft head and the bearing is increased, and the cooperation is poor, and the ink mark is caused by the tremor when the pressure is combined. In this regard, it is advisable to make trapezoidal traps in the inner liner of the rubber in order to reduce the impact during the imprinting state and reduce the degree of ink bar marks. In addition, serious wear on the roller bearings should be considered to take repair or replace the new bearing replacement to eliminate the traces of ink marks.

5, plate roller or rubber roller lining is too large. If these two conditions exist, stripe ink marks will be caused due to the inconsistency of their surface line speeds, and at the same time, the rollers will suffer shock vibration when they are imprinted. Therefore, when the two rollers vibrate, they will easily cause friction and cause ink marks. In addition, there are cases where the ink stick is easily caused by the pad of the pad being too large due to insignificant imprinting of the mouthpiece (light pressure). In this regard, the thickness of the lining should be accurately adjusted, and the ink layer should be uniformly transferred with the minimum printing pressure so as to maintain the consistency of the line speed between the rollers as a precondition. When adding a piece of paper to the mouth part of the mouth, use a gradually heating pad method, and do not add a pad at once, so as not to produce traces of ink marks.

6, Blanket (blanket) is loose, rolling friction easily occurs when rolling, so there will be a strip of ink marks. Therefore, measures should be taken to tighten the tension in time to prevent the production of printing ink bars.

7. When the self-adhesive Blanket is replaced, the old primer is not removed and the partial pressure inconsistency results in traces of ink marks.

For screen printing, I recommend using 165-27Y PW mesh for four-color printing for my colleagues in the CD printing industry. Its greatest advantage is that the color will be deeper. (Printing the disk surface, full color will look better, and the Chinese I like the bright colors. Because there are a lot of proofs that are ink jet printed. I understand that this kind of mesh is used less often in the industry, usually with 31 diameters. When the color is light, the general The processing method is to increase the thickness of the photosensitive layer, change the adjustment on the machine such as soft squeegee, four-color ink coloring, I think we need to add the theoretical value of online offset printing, the conventional 300, 2000 single run 50 enough, For example, when the color becomes darker, the ink-sticking parameter is adjusted less, and once every hundred sheets are checked, there are signs of deepening. Add one or two parameters, and then check the color of 200 pieces. If it is still, add it, this is a way of thinking about it. Flexible processing, if the first parameter is adjusted properly, I believe that the color will not have much change, (according to the size of the printing plate to determine the parameters) ink supply balance is very important, I need experience I do not agree with the adjustment of the ink tank gap, How to do the next single, do the old single to be transferred back, no horizontal offset printing In the management and maintenance of equipment, offset printing is the most prone to color control problems, the color changes depending on the specific circumstances in the following areas: test machine film run enough, it should be more than 1,000 colors will be more stable, The cooling temperature of the ink booth, ink supply balance, turntable, pressure, blanket, and offset are the overall coordination of these aspects. In the case of a good mechanical performance of the offset printing press, it is not recommended to mobilize the machine. The problem is likely to arise. When the test machine, the experience is not enough, the ink parameters are not adjusted well, even after the adjustment, you need to make some fine-tuning according to the color change at any time, (the color change is not the case), I have done seven plants, in my place The list of 50,000 prints is barely visible to the naked eye.