Color Printing Product Quality Management

Since the 1990s, there has been a demand for small batches, varieties, and high quality in the printing industry. Users have increasingly stringent requirements on product quality. In print companies, credit competition based on quality assurance evaluation is implemented to enhance corporate branding. The quality of survival, to the credibility of development. Therefore, it is very necessary to manage the standardized quality of printing products.

The quality of color printing products should be controlled by the current qualitative management and experience, and gradually developed toward quantitative management and school system.

The quality of printed products has certain characteristics. It reflects both the quality standards of industrial products and the quality standards of art. At present, the quality and standard of printed products are generally divided into empirical qualitative quality standards and scientific quantitative standards.

First, set a live standard

In the production practice, people based on the appearance of printed products, without the means of detection, relying on people's feelings, according to actual experience to determine the quality of the product, known as the qualitative experience, can not grasp the law of product quality changes, can only be After the end of the printing, the assessment is made.

two. Quantitative quality standards

The quantitative standards for the quality of color printing products must be based on data and standardization. The best product quality can be achieved only if the work is managed under the quantitative control of scientific data. In the use of equipment and equipment, using quantitative data to reflect the quality can be roughly divided into the following areas:

1. Optical density measurement quantitative standards:

The optical density is affected both by the thickness of the ink layer and the ink concentration. Optical instruments were used to measure the density of the ink in the field, and the correct relationship between ink supply and dot area was obtained.

2. Determination of color value quantitative standards: In a certain ink thickness conditions, measuring the ink's hue, saturation and density, check the ink technical indicators.

3. Contour definition determination Quantitative standard: Contour definition refers to the physical form that dots, text, lines, etc. should have on paper.

4. Overprint accuracy determination quantitative standards.

5. Graphic size measurement standard.

6. High-profile dot reproduction rates.

In order to achieve the above quantitative standards for printing product quality and to achieve data quality and standardization of the product quality, we need to implement some testing methods.

1. Color signal strips. In the printing, the signal bar is set on the printing plate, the purpose of which is to control the average quality of the printed matter, and to solve the problem of ink color and dot unevenness in the printing start state and the final state, so that the repeated printing products can achieve the same printing effect of each batch of products. . Because there are many comprehensive factors that affect the quality of printing, the consequences of these factors will eventually reflect the changes in the printing and graphic sites. In order to manage the quality of prints, various signal strips are applied from printing to printing to grasp the changing patterns of the printing plates. Therefore, the color signal strip is the first step in the management of data quality.

2. In the field, density values ​​and dot gains, and the density of the ink in the field is closely related to the hue, saturation, thickness of the ink layer, and the physical condition of the paper surface. The hue of the image varies with the density of the solid. As for the expansion of outlets, the largest cause of changes in the color of printed materials is the multicolor printing. In addition to the dot gains, which have changed due to changes in the density of the field, they have also been affected by factors such as printing pressure, blanket status, printing speed, paper quality, and the number of screens. Therefore, in the printing process, the density of the field is controlled in an optimal state, and the dot enlargement and the density of the field are monitored at any time, so that the hue in the print job can be well controlled.

3. Secondment curves and dot gain curves. As we all know, network expansion is unavoidable, but only at different levels. However, if we are taking color separations on printed manuscripts, taking full account of such factors as dot gain, and adjusting the dots, then printing under this condition may be closer to the color of the original image.

4. Imageetter calibration. When the imagesetter outputs a film, if the percentage of dots actually output does not match the value that should be output, the printed version of the finished product must not match the hue of the original. Therefore, we must adjust the signage machine to an appropriate state.

How to ensure the correct transfer of outlets and achieve the correct reduction of color is the key to guaranteeing and improving the quality of color printing products. The digitization and standardization are important means for modern production, and they are an important technical measure for scientific management quality and improvement of technical and economic benefits.