Flexo Printing Application in Newspaper Printing (Part 2)

Traditional plate-making techniques use film for printing. It takes about 30 minutes to produce a color version, which is not only time-consuming, but also difficult to guarantee in terms of quality. The use of CTP technology not only greatly simplifies the platemaking process, shortens the platemaking time (the time required to produce a color plate is only 1/3 of the traditional plate-making time), but also reduces the phenomenon of dot gain, making the highlights and dark spots The loss of network points and the substantial reduction of grid connection have greatly reduced the ability of the printing plate to replicate.

At present, the world-famous prepress equipment and plate production companies have introduced practical CTP products. Representative manufacturers include Agfa, Heidelberg, Crosby Angel, DuPont, Barco, Kodak Polystar, BASF. , Hell, etc., the introduction of flexo direct plate system more newspapers to provide quality assurance with flexographic printing.

3. Flexo printing has advantages

Compared with offset printing, the use of flexo technology in newspaper printing has obvious advantages.

(1) The equipment cost is lower than the offset press. Under the same conditions of printing medium and printing capacity, the equipment cost of the flexo printing machine is about 1/3 lower than the offset printing machine.

(2) The printing speed is higher than the offset printing machine. At present, the printing speed of a flexo press can be divided into low speed (80-150 m/min), medium speed (150-300 m/min) and high speed (600-700 m/min). Since the flexo printing is light pressure printing, the sleeve printing plate can be used, the inertia unbalance force is very small, the paper is not easy to break, and has good running stability, so high-speed printing can be realized.

(3) Low weight newsprint can be used. Due to the stability of the flexo press, there is no effect of offset fountain solution on the paper properties, so flexo printing can use low weight newsprint (40-45g/m2). If thick paper is changed to thin paper, the average annual national newspaper printing paper can save about 18% (printing 54 billion yuan a year for opening calculations).

(4) The loss rate of flexo printing is low. The flexo printing machine has a shorter turnaround time, so the paper loss rate is low, about 2%, which is nearly 9 percentage points lower than that of offset printing. If we add the amount of paper saved by the use of thin newsprint, only paper will save about 27% of the paper annually. According to reports, the US "San Francisco Observer" has only used paper because of the use of flexo printing, saving $41 million annually.

4. Adoption of ink and short ink system provides guarantee for wide application of flexo

(1) Ink painting. Ink is an environmentally friendly ink that does not contain volatile organic solvents and can improve the printing environment. This is one of them. Second, the printed wastewater can be recycled after treatment, and all the waste ink can also be recycled and reused as ink. Third, the ink is a quick-drying ink, and there is almost no problem of dirtiness during printing.

(2) Short ink system. The use of a closed anilox short ink inking system can provide a stable ink for the printing plate quantitatively, and the inking performance is significantly improved. By changing the technical parameters of the anilox roller (the number of screen lines and the geometric parameters of the cells), the desired amount of ink is obtained for the printed product.

The use of a closed reverse squeegee system not only keeps the ink in a clean state during the printing process, but also maintains the ink's performance and ensures that the ink is consistent in color.

The ceramic anilox roller manufacturing technology has made a major breakthrough, can process anilox roller 1500 lines / inch or more, or 2000 lines / inch or even 2500 lines / inch high number of anilox roller. This not only greatly improves the service life of the anilox roller, but also creates conditions for high-speed, high-precision flexographic printing.

5. Good quality flexo printing

The use of flexo printing in newspaper printing has the following characteristics:

(1) Newspaper printing is mainly based on text, lines, and color blocks. Flexographic printing has the advantage of embossing, with clear graphics, neat and vivid images, and bright colors. In this regard, flexo printing is better than offset printing.

(2) It has good print reproducibility and can ensure consistent ink color.

(3) The number of screen printing screens can reach 133-150 lines/inch. With CTP technology, the resolution can reach 1270 dpi, which can meet the requirements of newspaper printing.

(4) Multi-color group printing can be easily realized, and the length of spot color printing can be utilized.

This shows that the quality of flexo printing can fully meet the requirements of newspaper printing.

In short, newspaper printing has taken a gratifying step forward from the era of offset printing and it has begun to enter a new era of flexographic printing. As a major newspaper printing country, China's newspaper printing industry should also make its due contribution.

Source: Bison