How to maintain consistency in the color of a batch of printed materials or ink during printing is a basic requirement and an important issue. For manufacturers, the packaging colors used in products have become an important means and symbol for identifying products (even company logos). If the appearance of the product packaging looks different, consumers may think that the quality of the product is unstable, and even suspect the authenticity of the product. Therefore, these well-known enterprises attach great importance to the color of product packaging and require their ink colors to be consistent.
The consistency of colors can only be said to be relative. It is more difficult to strictly control the color difference within the same batch, and it is more difficult to strictly control the color difference between large batches or batches. Plastic flexible packaging gravure printing is mostly multi batch printing and large-scale printing, and controlling color difference is a very important issue for plastic flexible packaging printing enterprises.
1、 Ink
Ink is one of the main factors determining the color consistency of printed materials. Ink itself also has the same batch color difference and color difference between different batches, which is an important indicator reflecting ink quality.
To solve the problem of color difference in plastic gravure printing, the first step is to choose ink with stable quality and no color deviation. For a batch of printed materials, it is best to use the same batch of ink (the best one-time preparation for spot color ink), as it is difficult to ensure that the color tones of different batches of ink are different. If the ink tone deviation is too large, it is difficult to control the consistency of the printing ink through other methods, especially when printing layered versions.
Secondly, the amount of ink added to the ink cartridge during each printing process needs to be regularly maintained with the addition of new ink. Especially for patterns with low ink content, if too much ink is applied at once, the ink will be oxidized and aged when exposed to air for a long time. For example, long black ink is gray, while new ink is not black; Long red ink will turn dark red, not as bright as new ink. Strictly control the evaporation rate of the mixed solvents used in the ink during the printing process. When the evaporation rate is too fast, the transfer rate of ink may decrease, thereby affecting the color of printed products.
