Flexo Printing Application in Newspaper Printing (I)

Flexo printing for newspaper printing first began in the United States in the mid 1970s. In 1982, the United States launched a special press for newspapers. Since then, flexo and offset have begun to compete in the newspaper printing field. The San Francisco Observatory, San Francisco Record, News and Observer, etc. all use flexo printing. And achieved good results. Now, about 30% of newspapers in the United States use flexo printing; in Europe, there are about 14 types of newspapers that use flexo printing; in Italy, about 25% of newspapers use flexo.

In recent years, flexo printing has also developed rapidly in China, but overall, China's flexo printing technology is still in its infancy. In the total printing volume, flexo printing products accounted for only about 1.5%, and mainly used for printing paper boxes and corrugated boxes. Flexo printing has not yet been applied in the newspaper printing industry in China.

Problems with Offset Printing

The basic requirements for newspaper printing are: first, to be time-efficient, to provide newspapers for the majority of readers at the fastest speed; second, to meet quality requirements, to have clear graphics, bright colors, and good visual effects; and third, to be economical, Under the premise of meeting basic requirements, minimizing costs should be minimized. The fourth should be environmental protection. Under the condition that the international community is increasingly demanding environmental protection, the basic conditions for meeting the requirements of environmental protection should be printed. Below, we will make a brief analysis of offset printing and talk about offset printing.

1. Adjust the structure of newspaper printing

At present, in the printing of newspapers in our country, it is almost the world of offset printing. Regardless of the size and amount of printing, all use offset printing. While Europe and North America broke the single pattern of offset printing in the 1990s, we should also rationally choose the printing method based on specific circumstances. For example, the cost of offset printing for newspapers with tens of thousands of copies will increase significantly. At this time, different printing methods can be selected according to different requirements.

2. Excessive paper loss rate and scrap rate is a prominent problem in offset printing

In offset printing, controlling the ink-water balance is an important issue, and achieving a water-ink balance in offset printing requires a process. Under normal circumstances, it takes about 15-30 minutes to adjust and test the printing stage from the time of starting up to enter a stable working state, which will inevitably increase the loss rate. In the offset printing process, there are many factors that affect the ink-water balance, and most of these factors are changed. Even under normal printing conditions, waste products may appear due to changes in certain conditions. For example, the loss rate of sheet-fed four-color offset presses is generally as high as 7%-15%, and the loss rate of web offset printers is even higher than that of sheetfed offset presses. Therefore, from the economic point of view, offset printing is not the best.

3. Offset printing does not have much advantage in printing quality

Offset printing is of higher quality and is based on many conditions. If the surface properties of the printing materials are high, fine prints can only be printed when higher-quality, higher-quality coated paper is used. Printing on newsprint is prone to the following problems: (1) offset printing uses fountain solution, and newsprint paper is highly water-absorptive, and the whiteness of the paper will decrease after absorbing water; (2) the surface roughness of the newsprint will affect the clarity of the text. (3) In the printing process, it is easily affected by external factors, and the printing quality is poor in stability. It is prone to defects such as uneven ink and dull colors.

4. Offset printing is at a disadvantage in environmental protection

Offset rotary printing inks are low viscosity solvent inks. The solvent content of the ink is high. Without the oxidation of the conjunctiva catalyst, it is directly absorbed by evaporation and evaporated by heating. It is difficult for the prints to be fully dried within a few hours, not only in the printing process. Dirty troubles occur, and when the reader gets the newspaper, the ink will still stick to his hands. In addition, solvent-based inks have a strong odor, which is detrimental to both the operator and the reader. In addition, volatile organic solvents in the ink are contaminated by the environment. Therefore, rotary offset printing ink is a contaminating ink and its use should be gradually restricted.

5. Offset printing has certain requirements for paper

Offset printing has a higher printing speed and uses fountain solution. If the paper is too thin, it may cause breaks. Therefore, the paper used for offset printing should not be too thin, and should not be less than 52 g/m2 in general, which will also increase the cost of printing products.

6. Offset has higher requirements on the technical level of operators

Because the structure of the offset press is relatively complex, the adjustment position is the most among various types of printing presses, and the control of the ink-water balance is difficult to grasp. Therefore, the operator's technical level, basic knowledge and skills are all higher requirements. According to reports, in the offset printing industry, less than one-third of the basic requirements of the lead printer can be seen, it is obvious that it is difficult to cultivate a relatively good offset printing machine.

In summary, in the past 10 years, China's newspaper printing has achieved offset printing, and offset printing has played a significant role in the development and progress of China’s newspaper industry. However, with the rapid development of printing technology, the use of offset printing in newspaper printing is not the best choice. This trend has been proved by the development trend of European and American newspaper printing. In the future, China's newspaper printing should adopt flexographic printing technology on the basis of continuing to improve printing quality and reduce costs.

Application of Flexo Printing in Newspaper Printing

After many years of development, flexo printing technology has made remarkable progress. Especially in recent years, the key technology of flexo printing has made major breakthroughs, thus creating extremely favorable conditions for the application of flexo printing in the newspaper printing industry. It can be considered that the flexo printing technology has been increasingly perfected and has entered the stage of practical application in the field of newspaper printing.

1. The application of digital workflow before printing

Adopting a digital workflow is an important part of improving timeliness, reducing costs, and improving quality. Its main contents and functions include open systems, flexibility in making and editing and finally modifying files, PDF language format, electronic document exchange, trapping, and spelling. Large version and digital proofing and RIP output once. Adopting this system can not only greatly reduce the number of process steps, shorten the working hours, but also eliminate the influence of subjective factors of manual operation and ensure the quality of prepress processing. China's newspaper industry has adopted a digital process that has a good foundation. If we further improve and improve the degree of standardization and standardization, we can greatly improve the technical level of our country's newspaper prepress digital workflow.