How to make a great gravure spot color ink preparation program?
In recent years, gravure flexible packaging products, the number of printing color showed a significant increase in the trend, gravure spot color printing plate, gravure spot color ink usage increased year by year trend. The increase in the number of printed colors makes the printing of flexible packaging products increasing, the rate of bad products increased, especially due to the number of poor color caused by the rapid increase in the number of bad products.
There are many reasons for the color difference, gravure spot color ink is one of them. In the gravure spot color ink preparation, the current domestic vast majority of ink production enterprises still rely on the experience of technical staff to color, and by the naked eye to judge; and foreign and joint venture ink production enterprises have long been widely used computer color matching software, spectrophotometer and Automatic proofing system to ensure that the gravure color ink color consistency.
In the gravure spot color ink preparation process, the printing film substrate, gravure printing roller and printing process set and other elements of ink production enterprises must understand and master the key issues, the final production of gravure spot color ink The quality will have a great impact.
Relationship between Film Substrate and Color Reproduction of Gravure Spot Color Ink
In the actual production of flexible packaging enterprises, printing film base varieties are more, often customers because of the product range and specifications of different film substrates need to print the same graphic (especially with the spot color ink printing Graphic), such as QS logo, company LOGO, etc., and requires the color of these pictures must be consistent, the color as small as possible. Therefore, the same gravure spot color ink can meet this requirement, need to be judged by experiment.
The relationship between gravure roll and gravure ink color reproduction
At present, gravure printing roller is usually used in electronic engraving, image file production is completed, the need for each color plate roll (of course, including spot color roll) to determine the specific electric carving process parameters, such as carving lines, carving needle angle, carving Cable angle, engraving curve, dark tone, high light and trench and so on. As the selected electric carving process parameters will directly affect the depth of the plate network, determine the amount of transfer of gravure ink, thus affecting the final print on the color effect. Therefore, the experiment and confirmed that the main color carving process parameters of the special color gravure printing roller is a prerequisite for the accurate preparation of gravure color ink.
Practice has proved that even with the same printing ink, the same printing speed, the same film substrate, due to gravure roll roller carving process parameters are different, the final print color will have a greater difference, △ E up to 6. Therefore, in the design stage of gravure spot color ink, it should be clear customers to be printed products, spot color roll carving process parameters and to be considered, the spot color ink and gravure printing roller matching as an important reference The
The relationship between the printing process (ink viscosity, printing method, whether to use white ink backing) and gravure spot color ink reproduction
Gravure machines are usually designed with the highest printing speed, while the actual production of the printing speed is generally slightly lower than the design of the highest printing speed to ensure that the gravure press in a good stable working condition, to minimize equipment wear and tear. Gravure ink is a kind of liquid ink with good fluidity. The general rule between the viscosity and the printing speed is as follows: the printing speed is faster, the lower the working viscosity of the ink is required, and the higher the working viscosity of the ink is required; In a certain range, gravure printing speed and gravure printing ink inversely proportional to the working viscosity. Gravure spot color ink is also applicable to this general law, the working viscosity directly affects the gravure spot color ink color concentration level, and gravure spot color ink color density changes will lead to print on the spot color graphic color.
The same printing ink, the same gravure roll, the same film substrate, when the ink viscosity is different, the final print color will have a greater difference, △ E up to 10. Therefore, it is clear that the printing speed of the customer's gravure printing machine and the working viscosity of the gravure color ink required at this printing speed are the prerequisites for preparing the gravure color ink.
The same printing ink, the same gravure printing roller, the same film substrate, using different printing methods, the final color of the printed matter will be a certain difference, △ E up to 7 or more. Therefore, a clear customer printing products to be printed method is the preparation of gravure color ink in the necessary conditions of the four.
This paper describes the film substrate, gravure printing roll, printing process is the impact of gravure spot color ink preparation of the key elements, the general flexible packaging enterprises will this as a potential quality needs. To this end, gravure ink manufacturers need to gravure spot color ink design at the beginning of these implied quality requirements to identify, quantify, and converted into gravure spot color ink performance indicators, thus determining the appropriate ink production Technology, design the correct experimental ink formula, so as to continuously improve the improvement, and ultimately close to or achieve customer satisfaction goals.