Chromatic aberration is very common in the carton printing industry and is directly related to the printing effect. People find it good or bad, comfortable and uncomfortable.

These customers have strict requirements on color when making cartons for big brand products such as Wahaha, Mengniu, Hisense, Haier, and Midea, because it directly affects their brand influence and product sales. Imagine, if the appearance of the carton is not good, the impression is that the product is not good, sales will naturally be greatly reduced. The reason why many carton factories can not get these customer orders is basically because of the color difference.

So where should we control the color difference?

From the color sample and color card control

The source of printing color is the color sample provided by the customer. If the color sample is not accurate, the production unit cannot guarantee that the printed color is consistent with the customer. After the production unit takes the color sample from the customer, it should be compared with the color sample for printing proof, and determine the printing color at the same time with the customer, and set the upper and lower limits of the printing color. After the color sample is prepared, the manufacturer is strictly preserved by a person. Swatches and color cards are changed every three months to achieve hue, name and saturation.

This facilitates consistency in color between the customer and the manufacturer, who can obtain accurate printing color requirements and can exercise reasonable control within the color range.

Control from ink

In the actual printing process, the two characteristics of ink viscosity and PH value need to be controlled. Confirm the viscosity and PH value of the ink when proofing. After the customer confirms, the viscosity, PH value and fineness of the proofing ink are re-made and installed for inspection and execution; at the same time, the upper level first stirs the ink and installs the ink pump on the ink supply system; if the ink is not stirred for a long time, the resin in the ink will precipitate and once it does, the color of the ink will become darker. Therefore, the increase of stirring ink pump is beneficial to the control of ink viscosity.

Ink control lies in the data recording. Data values are used to control the color of the ink. At the same time, the ink stirring pump is used to control the viscosity of the ink, so that the resin in the ink flows, which can improve the flow of the ink. This is one of the necessary conditions for consistent color.

Control from machine speed

The speed of the printing machine is a very critical point. For example, there will be a big difference in printing color between 70 sheets/minute and 180 sheets/minute. Since the printing machine has medium and high speed rubber rollers, the vibration of the equipment is also different; the vibration of the equipment brings the ink volume between the rubber rollers, and the color becomes darker when it touches the ink volume.

Therefore, the speed difference between the printing machine and the normal production speed will not be too big. To maintain the printing speed during the production process, it is necessary to maintain a uniform speed.

Printing Pressure Control

Printing pressure is also an important factor to control in order to achieve consistent color for the same batch of orders. This is because too much or too little printing pressure also directly affects the variation of printed colors. The printing pressure of this machine includes two aspects, one is the contact pressure between the anilox roller and the printing plate, and the other is the printing pressure between the printing plate and the cardboard. Therefore, in order to control the consistency of the printing color, a stable and uniform printing pressure is maintained during the printing process.

The effect of printing pressure on color is not the main reason. The printing pressure has the characteristic of indirectly affecting the printing color, so the printing pressure should be controlled lightly.

Ensure that the anilox rollers are clean

In addition to the above 4 points, be sure to clean the anilox rollers of each printing unit before printing. This is because if the anilox roller mesh is clogged, it will affect the uniformity of ink transfer and the color of the printed image will be uneven.

The plot of the anilox rollers is very important. If the anilox is blocked, it will directly reduce the amount of wit harmonic ink, the printed color will be light, and the printed color saturation is not high enough. Therefore, the anilox rollers of printing machines should be cleaned regularly. Test.

Carton printing, as long as the above points, the color difference can be basically controlled within the permissible range.