Talking about Printing Quality Control

The printing industry is the industry with the most potential for development in the 21st century. It has developed closely following the advancements in world-class information technology, computers, and advanced optical and electromechanical integration technologies. It has been closely integrated with new science and new technologies and has developed into a pillar of the country. One of the industries.

As far as individual printing companies are concerned, in order to keep up with the tide, establish and improve the printing quality monitoring system, improve the quality management system, and ensure the stability and improvement of product quality, it is the key to achieving rapid development.
As for the quality of printed products, various requirements will arise in printing due to different uses. In many cases, quality standards are negotiated between the user and the printer. In general, the quality of printed matter can be measured by three criteria, namely raw materials, printing, and post-processing. The quality of paper and ink directly affects the printing effect; the quality of the printing refers to the clearness of the color, the accuracy, and the fitting degree of the four colors; the post-processing requirements are neat and accurate. If you meet the above requirements, you can basically count as qualified prints.

To ensure that the print quality is qualified, it needs to be implemented at different levels of management and production. The quality management system implements overall quality control from a macro perspective, ensuring the quality, integrity, and stability of the quality control. The quality management system must be From the perspective of: on the one hand, it is necessary to have a hard environment such as equipment, software, and systems; on the other hand, quality control standards need to be established to improve the level of operators and improve the soft environment.

Quality control is always an indispensable part of the printing process, and its important part is conventional control. It is carried out by personnel who are directly involved in the production of printing. This actually refers to a type of operating specification. It usually consists of three parts: the preparation for printing, the control of the printing process, and the inspection of printed products.

First, prepare <br> <br> graphic quality of pre-printed checks pre-printed first is to check the content of the graphic. It needs to check the construction slips and proofs, and at the same time check whether there are any errors or defects in the images, words, symbols, etc. This kind of inspection is relatively simple, as long as the thickness meets the standard and is smooth and clean.

Second, it is the inspection of the image quality. The quality of the image on the plate is the basis for the quality of the print. Without high-quality images on the plate, there is no high-quality print. The inspection of the image quality is performed by checking the dots (because the printed image is expressed by dots regardless of whether it is a monochrome continuous-tone original or a color continuous-tone original). The contents of the inspection are conducted in two aspects.

1. Image imprinting check. The visual inspection of the corresponding parts of the proof and the printing plate is compared to see if the shade of the printed product is consistent. In addition to the overall observation, you can also choose to focus on observations. Observe whether the dot size is the same with a magnifying glass (due to the spread of ink in the printing and the reflection of light, the printing dot must have a certain degree of expansion. Therefore, the dots on the plate should be slightly smaller), the focus of the observation area should be selected in the deepest position , the most shallow part and the most important part of the image content. The hue of the main parts after printing meets the requirements, and there will be no big deviation in the printed matter.

2. Check the quality of outlets. The quality of the network is an important guarantee of image quality. With high-quality outlets, there will be high-quality reproduction and high-quality color reproduction. The dots on the plates must be real, the edges should be clear, and the best surrounding is bright and clean. Hairiness at the edge of the mesh will reduce the ink's adsorption performance during printing, and the mesh itself will exhibit unstable conditions. It is usually a magnifying glass with a magnification of 10 times or more to check the dot formation.

Second, the printing process control <br> <br> lithographic printing process, paper, fountain solution, printing ink and in contact with each other, more varied, the slightest mistake will cause uneven ink and other ills. So you must do the following two things:
1. Before the printer is officially turned on, the printing machine must undergo a trial printing operation so that the printing color is the same as the proof color.
2. The printing process is completed during high-speed operation, so the control of the ink balance will be critical. Moreover, our experience tells us that in the printing production, we strive to achieve constant ink, diligently look at the water, diligent inspection, and are the most effective quality control measures in the printing process.

Third, the printed product testing <br> <br> each print shop or printing has finished checking this post. The main contents of the inspection of printed products are as follows:

1. Use colors and rules to check the color and fit of printed products.
2. Judging the overall quality of the printed product, including color, gradation, registration, surface conditions, and drying conditions. Mark bad products and draw them out in a timely manner.
3. Count check, that is, check whether the number of sheets is sufficient.

The data quality of the printing quality control is through the necessary test methods, and the necessary control factors for the printing quality are measured and recorded in the form of data to serve as the basis for quality control; standardization is to synthesize a series of energy through a large amount of data. Guide the rules of production, such as formulas, curves, charts, data, etc., so that they can follow rules and have moments to follow. There are three criteria for measuring the degree of dataization and standardization of print quality control: First, stability, second, repeatability, and third, high efficiency.

The conventional control of printing quality is a very complicated, meticulous and important work for printing companies. It directly affects the image of the printing company, and it also affects the survival and development of printing companies. Therefore, it is necessary to establish an authoritative quality control department to promote continuous improvement of the company's quality system. This improvement is mandatory and authoritative. Only in this way can we gradually develop a quality-conscious atmosphere. At the same time, employees should be trained to combine rewards and punishments to improve the quality awareness of operators. If the operator's printing technology is not hot, the quality is low and the loss is high, which inevitably increases the cost and weakens the competitiveness of the company.

Looking at the current status of China's printing industry, the dataization and standardization of printing quality control is far from the developed countries. Therefore, how to improve and strengthen the digitization and standardization of print quality control from the technical and management perspectives is the responsibility that the majority of printing workers cannot shirk, and it will also be a printing company's ability to survive and develop in the fierce competition in the future. The essential.

â–  Zhang Jianxia

Reprinted from: "Sunny" (Author: Guizhou Institute of Surveying and Mapping)