Gravure ink preparation

At present, most of the gravure packaging companies in China are limited by economic conditions, and all kinds of plate cylinders used are produced by customers or production companies to a special plate-making company. Because of the high cost of the gravure cylinder and the constraints of the process conditions, it is difficult to determine the hue of the spot ink used as quickly and easily as offset printing before the formal printing. Therefore, how to allocate the same color as the original (standard sample) in the shortest time possible without delaying normal production is one of the elements that cannot be ignored in the multicolor gravure printing process.

To master the rapid deployment of gravure inks, first understand the difference between gravure printing and offset printing. In the printing method, gravure printing is direct printing. Its reduction of colors and reproduction of levels are achieved through the depth of printing plates on the Internet, and most of the soft packaging in the field is printed with ink of 3 g/m2. Offset printing is an indirect printing. It reproduces colors by the size and number of printing plates on the Internet, and its amount of ink is less than half of gravure printing. In terms of price, the cost of the gravure plate is high (1000mm long version, for example, each cost is between 2000-3000 yuan). It is impossible to make multiple plates at the same time as offset printing at the time of plate making. Zhang is about tens of yuan. It can only produce one piece per color, nor can it be color proofed by a special proofing machine before it is on the machine. Therefore, a comprehensive understanding and mastering of the entire gravure printing process, the principle of the three primary inks and the subtractive color principle are essential knowledge for deploying various color inks. At present, the gravure coloring process is basically started after the low-speed registration of the platen. It is based on proofs provided by customers and ink guides provided by ink manufacturers. After researching and analyzing the color of the manuscript, determine the type of the original ink, and then determine a small amount of the original type of ink deployment, each time after booting to print proofs and the manuscript under the standard light source carefully check and identify, if there is a difference to deploy again, until Same color as the original. Matters needing attention during deployment are:

1, deployment personnel should be familiar with the gravure process and have a strong ability to identify hue, but also familiar with the principle of color ink master three primary color toning rule. When deploying, it is imperative to adopt a step-by-step approach with patience. Do not rush to achieve success so as to avoid unnecessary waste.

2, to be familiar with the common color difference phenomenon in the deployment process. Such as: green yellow, you can add a small amount of blue ink to correct color; black impure, you can add a small amount of blue ink; silver ink darkens after a longer period of darkening, you can add a small amount of white ink to correct; Qingjin added a small amount of yellow or goods The red ink can present a golden, gold-red effect; the cyan can be lighter, and a small amount of magenta ink can be added.

3, coloring to fully understand the factory equipment daily printing speed and printing pressure, and control the ink viscosity. Because the characteristics of gravure determine the different printing speeds and pressures under different pressures, the inks prepared at low speed must be reprinted with the original after the printing speed is opened to the daily speed, so as to avoid the color difference. Cause waste. At the same time to maintain consistency of ink viscosity, if conditions are best coupled with the ink circulation system to ensure that the ink has a good fluidity. 4. When observing the hue of printed samples, it is best to perform under a standard light source. If it is a soft packaged print, the observation table top must be clean. It is better to lay a layer of milky white plastic or to check the original directly against the milky white plastic to check the original. This can avoid the visual error caused by the conditions.

Source: 21st Century Fine Chemicals Network