Digitalization and Advance Control of Color Management of Cigarette Label Printing

Digitalization and Advance Control of Color Management of Cigarette Label Printing

The color management in the printing process of Cigarette Box occupies a pivotal position in the entire color management system, because the quality of the work at this stage is directly related to the quality of batch products, especially in the field of cigarette label printing where stability is the first requirement, If the control is not good, it will be scrapped in batches, customer complaints will be returned, and it will directly affect its reputation.

      The importance of data standards

      The so-called standardization is the maximum standardization. The same process conditions, different places, different times, different operators to print, the effect should be exactly the same. This requires measurement and control of process parameters to stabilize process conditions. This requires us to determine the key processes according to the characteristics of the company in the printing process, and to control all the processes in the printing process in order to achieve the purpose of specialized production.

      In traditional printing production, the thinking of employees is perceptual, empirical and disordered, and skills are often taught by masters and apprentices. In the thinking habits of some old masters, they always think that printing production relies on the experience passed down from generation to generation. It is unclear and unclear. With more experience, you will know it naturally. In fact, this is an unscientific and imprecise practice. Modern printing requires many steps to be completed together. To maximize cost savings, improve production efficiency and ensure stable printing quality, a scientific and strict system and process flow are required.

      The standardization and standardization of enterprises can form strong productivity. A research institution in London, England, has conducted a large number of long-term data statistics, and concluded that 13% of the economic growth in Europe is due to standardization, which is much higher than the driving force of patented technology on the economy. We must be acutely aware that the age of rationality in the printing industry has arrived. In recent years, a business strategy alliance formed by a number of printing industry suppliers and academic groups has implemented a unified "job identification format", which not only controls the information format of "output" and "input" by establishing a standard The effective operation of the production process has become the consensus of "standardization, digitization and standardization" in the industry, and is called a milestone in the standardization of the printing industry.

      Standardization is indeed conducive to printing quality control, effectively reducing costs and improving service levels. The printing production process is long and complicated. The control of printing quality lies in the whole process. If any process link is handled improperly, the skill level of operators in each link is uneven, and the operation is not standardized, it is impossible to produce high-quality printing products. For each production process, set control points and control elements, and conduct process control based on whether they meet the standard requirements as the basis for flowing into the next process.

      Second, the color data of Cigarette Box products

      For Cigarette Box printing enterprises, while formulating the color quality standards of printed products, the quality standards of printing materials (ink and paper) must be formulated and effectively controlled in order to achieve the required printing quality. The color and paper qualification tolerance range of the printed product can adopt the same control standard as that of the printed product user (cigarette enterprise); or, according to the production conditions of the printing enterprise, a relatively strict control standard can be formulated

      To formulate the standard chromaticity coordinate value of the ink, the same standard chromaticity coordinate value as the specified target color of the printed product can be used; or, use an automatic ink scraping machine to measure the ink color sample obtained after scraping the specified ink. The standard chromaticity coordinate value of the ink. In this way, the incoming ink does not need to be printed on the machine, and it can be easily detected and controlled. The color difference of the printed product is the comprehensive performance of all the influencing factors. Therefore, for the quality control of incoming ink, a relatively strict qualification tolerance must be formulated In this way, the printed product obtained after synthesizing the color difference changes caused by other influencing factors after printing can meet the final quality requirements.

      1. The formulation of target color standard chromaticity value

      Cigarette Box trademark color quality management can use spectrophotometers and color data processing systems. The minimum measuring caliber is 3mm; therefore, the actual measured area of the cigarette label must be greater than 3mm to be meaningful; it must be greater than 5mm to facilitate detection by staff and obtain good repeatability.

      After the Cigarette Box trademark is wrapped, it is covered, and it does not affect the place where the glue is applied, and prints a 5-8mm diameter detection color block for all colors that need to be controlled.

      Sampling 20 to 100 or more proofing trademarks, after visual observation by the standard setting department with the human eye, the proofing trademarks that meet the design color requirements and the difference between the proofs are within the width of the human eye as the standard color sample.

      Measure the chromaticity of each color of the above-mentioned standard color sample and make statistical calculations, and calculate the average value of L, a, and b as the standard chromaticity value of the color in the trademark; or use the target color in the color quality control software. In the setting function, the average value is measured to formulate the standard chromaticity value.

      Repeat the above operations to formulate the relevant L, a, b standard chromaticity value target color tolerance ranges for different trademarks and different colors respectively.

      2. Use the ΔECMC qualification determination method to formulate the tolerance range

      According to the product quality requirements, formulate a reasonable commercial index difference value (different colors with the same color quality requirements only need to formulate the same value) as the final tolerance range for color quality qualification determination.

      3. Production process control means

      Generally, process technicians always want to maintain constant process parameters and technical methods for production. However, in the actual production process, it is often difficult to achieve such ideal production conditions due to changes in one or another factor. For inks in particular, because manufacturers are constrained by the chemical and pigment industries, it is impossible to maintain the same level of quality between different batches of ink, especially the quality fluctuations between batches with longer production dates. Therefore, before printing, the specific process parameters must be properly adjusted on the basis of the original process standards according to actual production conditions such as material changes, in order to ensure satisfactory and stable color quality for different batches of printed products.

      Example 1: When the ink color saturation is slightly higher than the standard, and a new printing plate with a relatively deep score is used, the viscosity of the ink should be reduced or the printing speed should be increased for adjustment, and the thickness of the ink layer of the printed product should be reduced to reduce the printed product accordingly. Color saturation.

      Example 2: When the ink color of the ink is consistent with the standard, and the paper is slightly yellowish. Then, the ink color of the printed product obtained by large-area solid printing must be slightly yellowish. Therefore, the paper with relatively high whiteness must be replaced, or the yellow component of the ink color must be adjusted appropriately. In this way, the final quality requirements of the printed color can be achieved.

      4. Quality control

      During the printing process of Cigarette Box, due to the random errors of printing equipment, the technical ability of operators, the volatilization of ink components and viscosity changes, the blockage of printing plate notch, the fluctuation of printing speed, the change of drying temperature, and the change of environmental temperature and humidity, etc. It will cause the color quality of the same batch of printed products to fluctuate. Therefore, it is necessary to use a color difference meter to timely sample and test the semi-finished products during the printing process, understand the color difference deviation of the printed products and adjust the process parameters in time, so as to control the color quality of the printed products to fluctuate within the smallest variation range. Thereby reducing the rejection rate of printed products and improving economic benefits. According to whether the printing equipment is equipped with a slitting mechanism, the corresponding random sampling time shall be formulated, and the printing semi-finished products shall be sampled in time.

      5. Use the color difference measurement method to detect randomly sampled products for color difference analysis

      Note: The color difference analysis in the quality control process is not the judgment of the qualification of the printed product. If the sampling test results exceed the qualification tolerance range, the process parameters are adjusted for control, which will cause many unnecessary waste products. Therefore, it is necessary to adjust the process parameters in time according to the actual degree of chromatic aberration deviation. Combined with the relevant content of the CIELAB system in the basic theory of color, the color deviation deviation analysis is carried out on the above sampling detection data.