Six Tips To Control Printing Color Difference
Printing Color Difference
In daily life, we often say that chromatic aberration refers to the phenomenon of color inconsistency when the human eye observes objects. In the printing industry, the so-called color difference refers to the color difference between the printed matter and the standard sample provided by the customer. How to accurately evaluate product color difference is a very important part of the printing process. However, various factors such as light source, observation angle, and observer's own conditions during visual color measurement may cause differences in color evaluation.
So, how to control the color difference to make the printed matter close to the color of the design draft? Today, let's learn how to control the color difference through 6 elements in the printing process.
The printing color matching link is the core link in the whole color difference adjustment. Under normal circumstances, many technicians in printing companies only pay attention to experience or use their own feelings when color-grading, which is neither a standard nor a unified standard. Great variability. This kind of color matching, on the one hand, has no effect on the improvement of color difference, on the other hand, it is difficult to adjust the hue, and in addition, there is no scientific guidance for cultivating the color matching ability of employees.
Before toning, special attention should be paid to prevent the use of printing ink systems from different manufacturers for toning. It is best to use printing inks from the same manufacturer for toning. The colorist must fully grasp the hue and phase deviation of various printing inks. Helps to maintain control during the color grading process.
Before toning, if you use the printing ink left before, you must first find out the hue of the printing ink, check whether the identification card of the printing ink is accurate, it is best to use a scraping stick for scraping observation and comparison , and then add, before adding, the weighing should be strengthened, and the data should be recorded.
In addition, when adjusting the depth of the spot color ink, you can also use the metering method to adjust the color. When scraping the ink color sample, it must be uniform and have a white background, which is helpful for comparison with the unified standard sample. When the hue reaches more than 90% of the uniform standard sample, strengthen the viscosity adjustment, then proofing, and finally fine-tuning.
It is worth mentioning that special attention must be paid to the accuracy of the data during the color mixing process, which is very important for the subsequent summary of process data parameters. When the ratio data of the printing ink is strengthened, the color can be adjusted quickly and reasonably after several times of practice, and the problem of color difference can also be avoided.
In the production process, it is best to uniformly mix ink according to the size of the order, complete the color matching work at one time, prevent hue deviation caused by several color matching, and reasonably reduce the occurrence of color difference and residual printing ink.
Finally, when checking the color, you will find that even if the color looks the same under general lighting, it will look different under another light source. Therefore, you should choose a uniform standard light source for color viewing or color comparison.
Printing Doctor Blade Adjustment
During the production process, if the doctor blade is frequently moved, the working position of the doctor blade will be changed, which is not conducive to the normal transfer of printing ink and color reproduction. In addition, the pressure of the doctor blade cannot be changed casually.
Before production and processing, it is necessary to adjust the angle and position of the doctor blade according to the graphic condition of the printed plate roller. The angle of the doctor blade is usually between 50°-60°, and the doctor blade must pay attention to the layout The symmetry of the three points, that is, the ink layer on the left, middle and right should be the same. In addition, special attention should be paid to check whether the three points of the doctor blade are installed in balance before the knife is lowered, to avoid wavy, one high and one low situations, because this is very important for the hue stability of the printed matter.
Ink Viscosity Adjustment
Before production and processing, it is necessary to strengthen the adjustment of ink viscosity, it is best to adjust according to the expected machine speed, add solvent and mix thoroughly, and then start production. When the product to be accelerated to meet the quality standard, the viscosity can be detected at this time, and it can be used as the unified standard viscosity value of the product. This value should be recorded in real time and the entire product should be adjusted according to the data, so that the viscosity caused by the product can be reasonably reduced. The hue deviation problem caused by the change.
When testing the viscosity, the printing ink in the printing ink barrel or printing ink basin is usually used as the main detection object. During the normal production process, it is recommended to take a sampling every 20min-30min, so that the captain or technician can adjust according to the change of the ink viscosity value.
When adjusting the viscosity of the printing ink and adding solvents, special attention should be paid not to directly impact the printing ink, in order to prevent the system damage of the printing ink under normal conditions, the separation of the resin and the pigment, which will cause the printed product to fade and the color reproduction not enough.
Production Environment Control
It is more appropriate to adjust the humidity in the workshop between 55% and 65% under normal conditions. Excessive humidity will affect the solubility of the printing ink, especially the transfer of the shallow mesh area is difficult to display normally. Reasonable adjustment of air humidity has a good effect on the adjustment of ink printing effect and color difference.
Raw Material Selection
Whether the surface tension of the raw material is qualified will directly affect the wetting and transfer effect of the printing ink on the substrate, and will also affect the color rendering effect of the printing ink on the film, and it is also one of the factors affecting the color difference.
Ensuring the product quality of raw materials is a prerequisite for quality control, therefore, it is very important to choose qualified and reputable suppliers.
Improvement of Quality Awareness
Quality awareness refers to the perception of product quality by production, processing and quality management personnel. This perception is specifically reflected in the details of the work. In terms of adjusting chromatic aberration, it is mainly to improve the quality awareness of employees, strive for excellence in work, and shape the concept of product quality.
In general, when making a sample, it is necessary to strictly observe that the difference between the printed matter and the standard sample reaches more than 90% before starting production and processing; when the first piece is produced, it is necessary to assist the quality inspection personnel to strengthen the inspection of the first piece; in production, It is necessary to strictly require the team members to perform the quality management system; when changing the hue of the printing ink, pay special attention to the cleaning details of the printing ink basin and whether the bottom plate of the doctor blade and the clips at both ends have been replaced or cleaned in time.
Only by realizing the standardization of source and sample management can the color difference be reduced and avoided, so that there is no obvious color difference between each batch of printed products; only by paying special attention to the management of detailed operations and process data during production, Only then can we make better products, and then improve the comprehensive market competitiveness of enterprises.
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