Analysis of the relationship between ink presetting and ink balance

Ink presetting is the auxiliary control of the ink supply of the printing press, providing advance and digital support for printing ink adjustment, so that the layout ink color is accurately adjusted before starting. The ink balance is an important part of the printing process control. The dynamic balance between ink volume and water volume affects the transfer performance of the ink to the plate, and affects the actual ink demand on the plate. Therefore, there is a certain relationship between ink presetting and ink balance. The association. The application of ink pre-setting technology will promote the establishment of ink-water balance in the printing process, and good ink-water balance will also help the ink pre-effects to be fully utilized.

Ink presetting promotes ink balance establishment

1, ink and water balance

The ink-water balance concept runs through the entire process of printing production, especially establishing the ink-and-wash balance as soon as possible at the beginning of the boot process, which helps the printing press to enter normal operating conditions. A good ink balance is essential for print quality.

The ink-and-wash balance consists of two concepts. The first is the relative balance between the amount of water and the ink on the surface, that is, to ensure that when the ink is in the water-in-oil state, the volumetric proportion of the wetting liquid contained in the ink is 15% to 26%, and the maximum is 30%. . The second is to print the most real ink in the smallest amount of water. The first is the basic balance, and the second is the higher level of balance. The first kind of balance is relatively easy to get. There is no water, small ink, or large water and small ink. However, it is prone to water, large ink, or small water and small ink. The second state basically solves water and large ink or water. Small ink small situation.

The balance between ink demand and ink supply in the layout is the key link in the formation of ink and water balance. The degree of sophistication in the management of water and ink on the press is different. In a newspaper printer, the amount of water is adjusted in the range of the width of the four-sided printing surface, and the control of the ink is adjusted in the width range of about 40 mm. Ink adjustment is more meticulous, so it is easy to appear ink imbalance in a certain ink area. Therefore, to achieve the entire layout ink balance, water adjustment alone cannot be obtained, and it must be balanced through ink adjustment.

We found that when the newspaper and the association made a unified assessment and even internal review of each factory, ink was the lowest score among all four indicators, and poor ink-water balance was the main influencing factor. Therefore, setting the ink key according to the actual ink demand is one of the foundations for forming a good ink balance in the full layout. This is also a good promotion of the ink presetting for the ink and ink balance.

In addition, the printer controls the amount of ink in addition to the fine control of the ink keys, as well as the rotation speed of the web roller or the contact time of the swing roller on the sheet-fed printing press to effect the ink amount of the entire printing area. Control, these two controls need good cooperation in order to fully establish the ink balance of the printing press.

2, ink preset

The ink preset plays a crucial role in promoting the ink balance. The ink-water balance is a dynamic balance, and changes in water or ink will break this balance. At the beginning of power-up, it is necessary to establish ink-water balance as soon as possible, and during this process, if the amount of ink is always changed, the ink-water balance is difficult to establish. Through the ink presetting, the ink key opening on the printing plate has been accurately preset according to the situation of the layout before starting up, the relative opening degree of each ink key is also relatively balanced, and the ink key opening degree does not generally appear to be greatly adjusted. In this case, you only need to correct individual ink keys. At this time, the operator can focus more on the control of the total ink volume, and adjust the ink fountain roller speed to match the total amount of water in the layout to achieve a good ink-water balance.

Newspaper printing has strong timeliness, multiple layouts, and a high proportion of color layouts. In order to establish the ink and ink balance of the printing press as soon as possible, many of the leaders are first to magnify the water, and then adjust the amount of ink. In this way, adjusting the amount of ink generally does not appear dirty, but it is very prone to water and large ink. Newsprint paper has strong water absorption, wet and wet printing, and the amount of water is too large to cause excessive deformation of the paper, resulting in inaccurate overprinting and slowing down the drying speed of the ink. By ink presetting, more attention can be paid to the ink-water balance control, and at the same time, the problem of dirtiness during the ink-dyeing is solved, and the occurrence of water-big ink-on-black is also reduced from a certain extent.

In short, the ink preset can solve the problem that long-term ink balance cannot be established due to the large amount of ink adjustment after power on, and promotes the establishment of ink and ink balance as soon as possible, so that the boot report is greatly reduced.

Ink balance helps ink presets work

The amount of fountain solution and the amount of ink are related to each other, and this equilibrium state affects the degree of accurate transfer of the ink to the plate. The performance of ink-and-wash imbalance is mainly due to water, ink, water, ink, ink, water, and ink. No matter what kind of imbalance, it will directly affect the size of the ink supply on the layout. The poor ink balance and the certainty of the printing plate ink amount, and the good ink balance control helps to form a stable supply of ink, which helps the ink preset effect to be fully utilized.

The ink preset is to make the layout of the ink better, which is the same with the purpose of ink balance. Too much or too little water directly affects the transmission of the ink volume to the layout, thereby affecting the exact corresponding relationship between the actual ink demand of the layout and the ink supply of the ink fountain. In addition, an excessive amount of water also causes the fountain solution to be transferred to the ink channel system in the reverse direction, which affects the ink transfer efficiency, thereby affecting the accuracy of the ink presetting.

The accuracy of the ink preset refers to the amount of correction based on the amount of ink on the layout after the ink is preset. The state of ink balance determines the amount of ink on the layout. If there is no guarantee of ink balance, there will be no accurate ink demand. This kind of correction will not be accurately controlled. If the ink balance of the printing process is not good, the amount of ink on the layout will not perform well, and its preset effect will not be able to display.

The ink balance affects the full use of the ink preset effect. This is more evident in newspaper printing. The poor ink-water balance is one of the reasons that affect the ink preset effect.

Understanding ink presets
The understanding of the ink preset technology helps to apply it correctly. Since the ink preset provides accurate ink information and has been adjusted in advance, since the printer has a good ink balance, is it not necessary for the operator to adjust the printing?
Ink presets are not "precise". Ink preset is based on a mathematical simulation method, through a certain algorithm to convert the pre-press layout digital image description information to ink key information. This requires a process of partitioned ink coverage calculation, ink key value correction, and ink fountain roller rotation speed correction. All these processes are performed under the control of a standard mathematical formula.

As the printing press is a simulation device, the actual ink demand for printing will always change with the changes of the relevant environmental factors, such as raw materials, temperature and humidity, and adjustment of the printing press. Using mathematics standard algorithms to correspond to a simulated device, it is impossible to fully correspond to these variable factors. In addition, the printing ink division principle and the characteristics of the ink roller series, determines the ink supply and the corresponding part of the ink coverage is not completely corresponding, such as the adjacent two ink zone ink key opening can not be too different Otherwise, it will restrict each other; if the ink fountain roller rotation speed is given in relation to the current printing machine status and raw material characteristics, it is more of an empirical value. All these make the conversion relationship from the ink coverage to the ink key opening impossible to be absolutely accurate. The accuracy of the calculated ink coverage and the actual ink key amount is only 40%, and after correction, it is increased to about 80%. The remaining 20% ​​need to be corrected before or after starting the machine according to the status and layout of the press.

It should be said that this 20% correction is still an adjustment to the layout of the ink, which will still affect the ink balance of the printing press. The ink preset only increases the speed of the ink balance and reduces the difficulty of maintaining the ink and ink balance, but it is not necessary to pay attention to the balance of ink and ink.

In addition, ink preset can be understood as including "pre-" and "set" two processes, "pre-" means that you can pre-set according to the layout information on the printer ink key settings, this process requires prepress data support The ink volume calculation and correction software are used to calculate the relative amount of ink before booting, roughly equivalent to the work done by the CIP3 exporting software in the CIP3 technology and the CIP3 ink presetting station in the printing press.

The “setting” of the ink preset is to automatically or manually adjust the ink key according to the above information, which is roughly equivalent to the process of importing the ink preset information into the ink adjusting table with data interface, or manually adjusting according to the above information. It can be seen that the concept of ink presetting relies on "pre-printing." Providing advance and accurate adjustment support for printing presses is the core of ink presetting technology. The “set” of the ink preset is the requirement for the data interface capability of the printing press. The printer without the data interface can also be achieved through manual adjustment.

Ink presetting is a closed and automated presetting process. People always place their cores on the printer interface, that is, on the “set” process, which to a certain extent limits the rapidity of the ink presetting technology. universal. If you have a system that has a prepress data export and calculation correction function, ink presets can be fully implemented. It should be noted that CIP3 is just one way to achieve ink presetting, not all.