Corrugated board printing development

The corrugated carton that once served as the main force for transport packaging now has a more brilliant performance in the “image”. It bears the responsibility of the silent salesman in the sales market, and it has also developed into a dual-purpose packaging material for transport promotion. The color printing technology of corrugated boxes has also made great progress along with the changes in the market.

1. Hand-engraved rubber plate, monochrome letterpress printing.

This is a craft belonging to the 1930s. The printing plate is a hand-engraved rubber plate. The characters and relatively simple patterns are carved on the surface of the rubber plate with a carving knife. The engraving accuracy is poor, and the printing effect is not ideal. It only serves as a simple marking function and does not achieve decorating effect; printing Machine accuracy is low, drying time is longer, not suitable for high-speed printing.

The process flow is: the original is a rubber plate transfer pattern, an engraving plate, a correction, a monochrome printing

2. Hand-engraved photosensitive resin (thick), simple line color letterpress printing:

The plate is still mainly carved, but thicker photosensitive resin plates have begun to be used. The printed pattern is just a few simple lines, patches, and simple dot patterns. Printing inks are water-based inks with fast drying speed and full color.

The process flow is: the original photosensitive resin plate transfer pattern a sculpture plate a correction one (three) color printing

3. Photographic plate, color flexo printing

Since DuPont Co. developed the photosensitive resin flexo version in the 1970s, it has created a new era of flexographic printing, which has promoted the development of flexographic printing and has played a significant role in the printing of corrugated cardboard. Since then, flexographic printing has also become the main method of corrugated board printing.

The process flow is as follows: manuscript-negative image color separation film-exposure-development-drying-post-exposure-correction-printing

During this period, thinner photosensitive resin plates were used, the color separation process was more refined, and the printing images were more plentiful and the colors were more brilliant, which could play a promotional role.

4. Thin technology

In the early 90s of last century, thin plate technology was promoted in corrugated box printing, which greatly improved the printing quality and efficiency of corrugated board. Mesh printing was popularized in the printing of corrugated board, and UPC bar codes started on corrugated cardboard. Printed universally.

The flexographic plate that was originally applied to corrugated board printing is relatively thick. We call it a thick plate. The thickness of the photosensitive resin plate is about 3.94mm, 4.70mm to 7.00mm, and the plate is made of double-sided tape with a thickness of 0.10mm or 0.30mm. It is attached to a piece of transparence film with a thickness of 0.25mm to 0.30mm, thus fixing the plate. In the printing process, in order to ensure the normal transfer of ink, it is often necessary to set a pressure that exceeds the normal pressure, and the printing plate is deformed due to excessive pressure, resulting in a more serious dot expansion, and the printing quality is greatly reduced.

In order to overcome the severe dot gain generated by thick printing, thin plate technology has emerged. The use of elastic cushions to absorb excess pressure is the best way for thin plates to improve quality in corrugated box printing. The way of sticking is different from general flexo printing. It is to directly place the printing plate on a thick film base, and then hang it on the relative position of the cylinder with padding. The phenomena of expanding printing dots have been greatly improved, the printing has become clearer, the ink transfer effect has been improved, and the printing quality has also been greatly improved.

5. Offset direct printing

The manroland printing machine company in germany successfully launched Roland 900 printing machine in the market in 2000. It can print fine quality printing effects directly on cardboard and corrugated cardboard.

Roland 900 is an ultra-large-format printer that can directly print thick cardboard and corrugated cardboard. The main technical features are the paper guide rail components, the use of staggered synchronous wheels and adjustable paper guides, and the diameter of the feed roller is reduced. Therefore, the degree of bending of the cardboard is reduced, and the trapezoidal wheel on the transfer plate avoids the cardboard slap on the printing press. In addition, the most distinctive features include:
The improvement of the previous rule on the Roland 900 eliminates possible traces on the back of the corrugated board. According to the characteristics of the corrugated board, a rule can be developed that can be exchanged with the pneumatic side scale. Therefore, it is ensured that the corrugated board is conveyed correctly. Produce any damage.

Compared with flexo printing, offset printing directly prints with higher precision, the print quality can reach 175lpi, the printing speed can reach 11000/h, and even faster.

From the previous monochrome rubber plate embossing, to the current green environmental protection flexo printing and direct offset printing. The color printing of corrugated boxes also sees the development of printing technology.