Pre-printing for Corrugated Box Printing (top)

While people lament that quality of life is getting higher and higher, and commodity packaging is becoming more and more convenient, printing technology is developing at an alarming rate. As the most important form of product packaging, a corrugated box, its development has also experienced some ups and downs. From a single transport-type package to today's integrated transport, sales, display and other multi-functional integrated packaging. Today, corrugated box products have reached an unprecedented level both in terms of output and quality. In recent years corrugated cartons companies have launched a variety of high-end multi-color printing presses, hoping to achieve more satisfactory results in terms of printing quality and accuracy. Among them, preprinting is a new corrugated box printing process.

Pre-printing corresponds to the direct printing process, that is, printing corrugated cardboard first and then corrugated cardboard. According to the different ways of printing paper, rough printing can be roughly divided into three kinds: offset printing, pre-flex printing, and gravure printing.

Preprinted conditions

1. Paper requirements

Although the coated whiteboard paper has good color performance, when the high-temperature drying tunnel is bonded through the corrugated cardboard production line, the surface coating of the paper will have varying degrees of changes, which will directly affect the surface color pattern effect. Although the pulp-filled whiteboard can meet the high temperature requirements in the bonding process, its rough surface can easily lead to the loss of network points, misrepresentation, and large consumption of ink. White card paper can not only fully express the color effect of printing patterns, but also can adapt to the characteristics of high-temperature bonding process, and is the most suitable paper for pre-printed webs.

2. Ink requirements

The preprinting process also has higher requirements on the heat resistance and rubbing resistance of the used ink. Otherwise, when the printed glossy paper is subjected to flattening and drying, the printing pattern will be pulled and the ink will be dropped, which will seriously affect the surface quality.

Flexographic preprinting and gravure preprinting mainly use water-based inks and alcohol-soluble inks, which are non-toxic and odorless, meet the requirements of environmental protection, and are increasingly developed.

3. Equipment requirements

Offset generally uses a sheet-fed printing method. Gravure preprinting mainly uses web gravure printing presses, in which the gravure printing machine for gravure printing is a standard machine for gravure printing. Flexographic preprinting equipment mainly adopts satellite type flexographic printing presses. Satellite-type flexographic printing presses can meet the requirements of large-format printing and are high-end printing equipment. They are still mainly dependent on imports.

Offset printing remains attractive

Offset printing is the most popular and most mature printing method in China, and it also exudes great charm in the field of corrugated box printing. The printing of domestic high-grade corrugated cartons has always used the offset printing pre-printing process, that is, the first offset printing of the faced paper is performed first. This method can ensure good print quality, and there is no limit to the print batch size. Flexographic preprinting and gravure preprinting have high printing speed and high efficiency, but after printing, they need to be rewinded into a roll print, and then corrugated on a corrugated paperboard production line. Therefore, the cutting accuracy of a cutting device for a corrugated cardboard production line is required. Higher, and the plate-making cost is also higher than offset printing, suitable for long-lived. Compared with gravure preprinting and flexographic preprinting, if there are many types of products and the volume of a single product is not large, it is uneconomical to use a flexographic preprint and a gravure preprint, and offset printing is more adaptable to a short version and flexible. , personalized market development trend, it has been recognized by many users.

At present, many corrugated box manufacturers in China have had unprecedented interest in offset printing and have purchased automatic or semi-automatic cladding machines for supporting production.

Shanghai Jie Long Pudong Color Printing Company is mainly engaged in the production and printing of corrugated box packaging for alcoholic products, and has always been in love with the production method of offset printing and has achieved good results. The company uses all imported offset printing equipment to print corrugated cardboard paper, mainly offset presses from Japan's Mitsubishi and Germany's Manroland, KBA, and Heidelberg. It is understood that the current domestic offset printing equipment processing accuracy is relatively low, printing high-grade corrugated carton packaging products are somewhat incompetent.

It is understood that. The number of suitable orders for offset printing preprints is approximately 10,000 to 20,000, and it can also be accepted for small orders of 5,000 to 6,000 batches. Last year, the company achieved an output value of more than 100 million yuan, and is expected to grow this year.

The production of corrugated boxes using offset printing preprints has the following features.

(1) Print products outlets are rich in layers, strong in color, and of good quality.
(2) The equipment investment is relatively small, only ordinary offset printing equipment can be used.
(3) Because it is a sheet-fed printing method, product batches have little impact on the production cost, and they can adapt to the diversified and individualized demands of customers for packaging products, which are in line with the development trend of short-run on-demand printing.
(4) The overall production efficiency is not high. Although the offset speed is relatively high, about 13,000 sheets/hour, the overall production efficiency is not as high as the production efficiency of the line processing method and the processing cycle is longer due to the slower speed of the line-up.
(5) Due to the method of printing in the first place, when the surface paper and the corrugated cardboard are blended, the glue easily penetrates into the ink and causes the discoloration of the printing ink layer. Moreover, as far as the offset printing mode itself is concerned, the ink and ink balance problem is also more difficult to control.

With the development of fine corrugated cardboard, the direct offset printing technology of corrugated board has made great progress. In particular, the packaging boxes and gift boxes for food, toys, health products, and electronic products have been extensively used with E, F, and G-type micro-corrugated cardboard. Direct offset printing, and the design is more and more complex, more and more beautifully printed, direct offset printing also occupies a not small market share. Companies such as KBA and Manroland have introduced offset printing machines that directly print micro-corrugated cardboard, and their print quality is comparable to that of offset printing. But at present, this new technology is only applicable to fine corrugated paperboards, especially for G-type and F-type corrugated paperboards. For other corrugated corrugated paperboards, it is still necessary to use offset printing preprinting methods. Both complement each other. It is understood that a subsidiary of Jie Long Company has invested in the introduction of a corrugated board direct offset printing equipment this year, which is mainly for miniature corrugated box packaging products.

(to be continued)