Cigarette Box Of Matte printing color management data and future control

Cigarette Box Of Matte printing color management data and future control

 

Color management in the printing process plays an important role in the entire color management system, because the quality of this stage of work is directly related to the quality of batch products, especially in the field of cigarette label printing with stability as the first requirement. If it is not well controlled, it will be batch scrap, customer complaints and returns, and it will directly affect their own reputation.

 

I. The importance of datafication standards

The so-called standardization is the maximum degree of normalization. The same process conditions, in different places, different times, different operators to print, the effect should be completely consistent. It is necessary to measure and control the process parameters and stabilize the process conditions. This requires us in the printing process, according to the characteristics of the enterprise, determine the key processes, all processes in the printing process are well controlled, in order to achieve the purpose of specialized production.

In traditional printing production, the thinking of employees is perceptual, experiential and disorderly, and the way of master leading apprentice is often used to teach skills. In the habit of thinking of some old masters, the printing production depends on the experience passed down from generation to generation. It is not clear that it is unclear, and the experience is more natural. In fact, this is an unscientific and not rigorous practice. Modern printing needs a lot of steps to complete together, maximize cost savings, improve production efficiency and ensure stable printing quality, requires a scientific, strict system and process.

 

The standardization and normalization of enterprises can form strong productivity. A research institute in London, UK, has done a large number of long-term data statistics and concluded that 13 percent of the economic growth in Europe is due to standardization, which is far higher than the drive of patent technology to the economy. We must be keenly aware that the rational age of printing has arrived. In recent years, a business strategy alliance consisting of a number of printing industry suppliers and academic groups has promoted a unified "operation identification format", which not only controls the effective operation of production processes by establishing standard "output" and "input" information formats, but also becomes the consensus of "standardization, digitalization and standardization" in the industry. And it was called a milestone in the standardization of printing.

 

Standardization is indeed beneficial to print quality control, effectively reduce costs and improve service levels. Printing production process is long and complex, printing quality control lies in the whole process, any process improperly handled, each link operator skill level is uneven, operation is not standard, it is impossible to produce fine printing. For each process of production, set up control points and control elements, in order to meet the standard requirements, as the basis for the flow into the next process to carry out process control.

 

2. Color datafication of cigarette package products

 

For printing enterprises, the quality standards of printing materials (ink and paper) must be established and effectively controlled at the same time when the color quality standards of printed products are established. The conformity tolerance range of printed product color and paper can adopt the same control standard as that of printed product users (cigarette enterprises); Or, according to the production conditions of printing enterprises to formulate relatively strict control standards

 

The standard chromaticity coordinate value of the ink can be used to specify the same standard chromaticity coordinate value as the target color of the printed product; Alternatively, the data obtained from the measurement of the ink color sample obtained by the automatic ink scraping machine after the specified ink scraping sample is used as the standard chromaticity coordinate value of the ink. In this way, the incoming ink does not need to be printed on the machine, and the color difference of the printed product can be easily detected and controlled. The color difference of the printed product is the comprehensive performance of all influencing factors. Therefore, the quality control of the incoming ink must formulate a relatively strict conformity tolerance range, so that the printed product obtained after the color difference change caused by other influencing factors after printing must be integrated. To achieve the final quality requirements.

 

1. Formulate the standard chromaticity value of the target color

 

The color quality management of cigarette brand can use spectrophotometer and color data processing system. Its minimum measuring diameter is 3mm; Therefore, the actual measured area of the measured color on the cigarette brand must be greater than 3mm to be meaningful; It must be larger than 5mm to facilitate the detection of the staff and obtain good repetition accuracy.

Print 5 ~ 8mm diameter test color blocks for all colors to be controlled where the cigarette label is covered behind the package and does not affect the sizing.

 

After sampling 20 ~ 100 or more proofing trademarks, the proofing trademarks that meet the design color requirements and the differences between the proofs are within the human eye wide capacity are regarded as standard color samples after the human eye visual observation by the standard setting department.

 

The chromaticity of each color of the standard color sample is measured and statistically calculated, and the average value of L, a and b obtained is taken as the standard chromaticity value of the color in the trademark. Or use the average measurement in the target color setting function of the color quality control software to formulate the standard chromaticity value.

Repeat the above operation, and formulate the relevant L, a, b standard chromaticity value target color tolerance range for different trademarks and different colors.

 

2. Use ΔECMC conformity determination method to establish the tolerance range

 

Establish reasonable commercial index difference value according to product quality requirements (different colors with consistent color quality requirements only need to formulate the same value) as the final color quality conformity determination tolerance range.

 

3. Production process control means

 

Generally, process technicians always want to maintain constant process parameters and technical methods for production. But in the actual production process, due to this or that factor change, it is often difficult to achieve this ideal production conditions. Especially ink, because the manufacturer is restricted by the chemical and pigment industry, it is impossible to maintain the same quality level of ink produced in different batches, especially the quality fluctuation between batches with longer production dates. Therefore, before printing, it is necessary to adjust the specific process parameters on the basis of the original process standards for the actual production conditions such as material changes, so as to ensure that different batches of prints can obtain satisfactory and stable color quality.

Example 1: when the ink color saturation is slightly high relative to the standard, and the new printing plate with relatively deep score should be reduced, the ink viscosity or the printing speed should be adjusted to reduce the thickness of the printing ink layer to reduce the color saturation of the printing product.

 

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

 

4. Quality control

 

In the printing process, due to the random error of the printing equipment, the technical ability of the operator, the volatilization of the ink composition and the change of viscosity, the score blockage of the printing plate, the fluctuation of the printing speed, the change of the drying temperature, and the change of the environmental temperature and humidity, the color quality of the same batch of prints will fluctuate. Therefore, the color difference meter must be used in the printing process to carry out timely sampling detection of semi-finished products, understand the color deviation of printed products and adjust the process parameters in time to control the color quality of printed products in the minimum variation range of fluctuation. So as to reduce the waste rate of printed products, improve economic benefits. According to whether the printing equipment has a slaying mechanism, the corresponding random sampling time is formulated, and the printing semi-finished products are timely sampled.

 

5. Use color difference measurement method to detect random sample products for color difference analysis

 

Note: Color difference analysis in the process of quality control is not a qualified determination of printed matter. If the sampling test results exceed the conformity tolerance range, it will cause a lot of unnecessary waste products to adjust the process parameters for control. Therefore, it is necessary to adjust the process parameters in time according to the actual degree of color difference bias. Combined with the relevant content of CIELAB system in the basic color theory, the color deviation bias analysis of the above sampling detection data is carried out.