Second, printing equipment
(1) Transmission stability of printing equipment
The overall stability of the printing equipment will directly affect the stability of the image reproduction process. The stability of the printing equipment mentioned here includes the driving accuracy of the printing press, the dynamic balance of the printing transmission parts, the uniformity of the transmission speed, and the various components. The stability of the matching accuracy. These issues will directly affect the quality of the transfer process of the printed matter, such as the stability of the dot, the stability of the ink usage, and the stability of the pressure. These will directly affect the quality of the printed matter.
In actual printing, we must consider the accuracy and stability of the equipment itself for different printing products. If the stability of the equipment itself does not meet the requirements, it is absolutely impossible to print a good print. This also puts forward that in daily production, while ensuring production, do not neglect the maintenance and maintenance of the equipment itself. Having a stable operating equipment is a prerequisite for printing good prints.
(2) The positioning of the paper in the printing press is accurate and stable.
After the paper enters the machine from Federa, it is continuously transferred in the positioning and transfer mechanism of the machine. The accurate operation of each step will affect the overprint of the substrate.
The first is Feida, which includes various components on Feida. We must always ensure the stability of Feida's separation and transfer of paper. At the same time, we must pay attention to the maintenance of the air pump. We must pay attention to the replacement and maintenance of the worn-out parts.
·Then all the components on the paperboard, including the paper roller, brush, double controller, paper conveyor, etc., should pay more attention to the symmetry of the two parts of the paperboard under the premise of ensuring the reasonable working position and tightness adjustment. Sex. Avoid skewed paper.
·Front gauge, side gauge, swing tooth. Strictly adjust according to the angular position of the equipment to avoid inaccurate positioning and handover errors.
· The roller teether (including the impression cylinder teeth, delivery cylinder teeth), as above, should pay attention to the accuracy of adjustment.
All the above-mentioned institutions are directly related to the overprint relationship of printed materials. It is necessary to rationally adjust and ensure the absolute precise operation of these institutions. Only then can the printed products be more accurately overprinted.
(3) Embossing mechanism. The ideal working condition of the embossing mechanism is that the ideal printing pressure is used, and the pressure is stable and unchanged during the operation. (Pressure regulation principle see process control)
(4) Water (ink) road. The requirements of the water (ink) road are to make the water (ink) spread evenly, the pressure between the water (ink) rollers is even, and the pressure between the printing plates should be uniform and reasonable. The specific requirements must be determined according to the requirements of different machines.
Third, the control of printing process
With the ideal materials and good printing equipment, we may be able to print good printing products, but it is by no means necessarily able to print good prints. The next most important point is the need for reasonable control of the printing process.
(1) Shaiban. Shaiban is a very important part of the printing process. Let's take a look at the factors that need to be controlled during the printing process:
1) determine the correct exposure time; 2) determine the correct extraction time; 3) dust removal work; 4) adjustment range: 2% -98%; 5) determine the position of the printing plate rinse; 6) drying printing plate Quality control bar.
· The issues we should pay attention to in the printing work are:
Pay attention to the quality of PS version body
1. PS version background color is not good. 2. Improper development time. 3. After development, there is a "blue bottom" that causes the printing to be dirty. 4. Not easy to ink, PS printing on the machine is not easy to ink. 5. Local "flower version", paste version. 6. Interruption of the printing process. 7. Partially dropped. 8. Locally out of print. 9. PS plate surface roughness is not good 10. PS version of ink affinity, poor alkali resistance. 11. Improper proportion of photosensitive ratio. 12. Photosensitive film is too thin.
The above issues are all of our attention in the printing work. The appearance of any point will lead to a decline in the quality of the printed matter or even invalidation.
(2) Water and ink balance control in printing
1 water control. In fact, we don't need water at all in the final printed matter. Even we always complain that water has caused various defects for our products (such as the low ink gloss on the printed surface due to the presence of water). So we are always looking for a type of lithography that does not require water at all, so waterless offset printing has emerged. Although it has various advantages that are not comparable to water offset printing, the only drawback is that the cost is too high to make it impossible. Better promotion. Therefore, we also need to start with the printing of water. Because of restrictions on printing plates and inks, we still need water for traditional water-printing equipment. All we can do in printing is to keep the ink as thin as possible. Under the premise of reducing the water consumption, doing so can reduce the ink emulsification, make the edge of the dot clearer (the boundary of the oil and water is clear), and secondly, the ink can be smoothly transferred to the surface of the substrate, and the water volume can be reduced. The large resulting surface properties of the substrate are reduced, and the substrate absorbs water.
· To ensure that the outlets are clear and the blank space is not dirty, minimizing the amount of water used is a basic principle for us to use water in offset printing. Some people say that there is water printing. Controlling the quality of water helps us to master the printing. It does make sense to produce better printing quality.
