Bright colors and bright patterns are the basic requirements of food packaging bags. How to avoid deviations between printed products and design manuscripts must first identify the causes leading to chromatic aberration and suit the remedy to the case.
One.The print chromatic aberration caused by pressure discomfort
The printing process is ideal in the "three" basis, in order to thin layer of ink by balancing the printing pressure, the printing ink to obtain a more uniform. When printing pressure is insufficient or uneven, the lining body and the plate surface has bad contact, it needs to increase the amount of ink, ink layout to meet the visual effect, but it will not only increase the consumption of ink, and easy to produce color printing and printing quality problems dirty.
Two, color printing rollers caused by bad
Printing color printing machine, usually equipped with transfer rollers, ink roller and rollers three, which impact on the shades of ink are larger ink rollers and rollers.The elasticity, viscosity, and the roller center degree, hardness and surface finish, largely determines the quality of printing inks. If the existing roller flexibility and lack of stickiness, roller eccentricity, colloid and colloid poor finish excellent situation, brush ink uneven or unstable phenomenon caused by the printing process, so that the printed sheet printing ink is not consistent.
Three. The printing chromatic aberration caused by the bad ink feeding device
When the ink fountain roller center of iron or steel wear deformation, ink also wear deformation, and the control of the fountain roller rotating mechanism of the defects, the printing process of inking amount is not stable, which will cause the printing color. In addition, should pay attention to reasonable really to ink device, ink in the ink to increase or decrease the transport capacity, there are two kinds of adjustment methods, one is to adjust the ink sheet steel and ink (ink feeding) iron roller clearance is achieved; two is the size of the rotation arc by adjusting the ink roller to achieve iron.
Four. The printing chromatic aberration caused by the bad Edition
If the lithographic printing process is unwell, it is also easy to appear the phenomenon of printing color difference. In addition, if the water roller is used for aging or absorbing ink and impurities, it will affect the water absorption of the water roll and the uniform transfer of the wetted plate. Furthermore, if the bucket device Water Leakage phenomenon, will also affect the layout of printing uniform conveying water. The existence of these adverse circumstances, will destroy the layout of the uniformity and stability of ink transfer printing inks, make the difference.
Five. The printing chromatic aberration caused by bad ink
Printing color difference is easily produced by the discomfort of the thickness and viscosity of the printing ink. When printing, printing ink layer only to moderate and uniform, in order to better guarantee the quality of printing ink, and prevent printing stick dirty fault.
Six. The printing chromatic aberration caused by the poor material's material
In food packaging printing process, we can find that the difference of substrate material is also one of the reasons for printing color difference. For example, the difference between gloss and hue of printed matter will cause printing color difference. Taking aluminum coated paper as an example, there are differences in the color phase of the coated paper surface, which will cause the inconsistency of the printing color effect.
Seven. The printing chromatic aberration caused by bad machines
Sharp tools make good work。 Keep the machine in good performance, is a reliable guarantee for improving the quality of printing ink. However, if the machine has bad conditions, it is also the most likely to cause the problem of print chromatic aberration. Therefore, in peacetime, we should pay attention to the maintenance and maintenance of the equipment, and pay attention to the lubrication of the key parts of the machine.
Eight, printing chromatic aberration caused by poor printing plate
Printing plate is one of the basic elements of copy quality. In printing process, the printing plate must remain unchanged and no wear to ensure the stability of ink delivery. The printing process, if the network layout show paste version or wear and deformation, wear lines and expanding, such as space, ink volume change, will inevitably make the food packaging bag color deviation.
Nine, the difference between the characteristics of the light source and the different observation angles on the identification of the color of the printed matter
Usually the differential light printing inks, mainly in sunlight (natural light), fluorescent lamp and incandescent lamp as light source. They have different characteristics of the light source, and the color of the emitted light is different, for example, the sunlight is white and the color is relatively accurate. The light of a fluorescent lamp is green in white, similar to the sun. While the incandescent light is red with yellow color, so it is difficult to accurately identify the color. Although daylight and fluorescent lamps are somewhat similar, they should also be considered in the identification of high quality color products.