The hottest paperboard pre printing technology

Paperboard pre printing technology

I. comparison between pre printing and post printing of corrugated paperboard

traditional corrugated paperboard has been affected by the development of the global transportation industry. Carton production often adopts the following process:

corrugated paperboard production - Paperboard Printing - die cutting and slotting - Nailing box/gluing box

the best printing method of corrugated paperboard is flexographic printing, which has been a consensus at home and abroad. However, although flexo can be used for printing on irregular surfaces, the above traditional process method is only applicable to cartons with low printing quality and simple graphics and text, but not to cartons with exquisite 4-color or 6-color printing brushes with 48 lines/cm, 52 lines/cm or 60 lines/cm, so its use has certain limitations

in the market, the demand for high-quality cartons that can reflect products and corporate image is becoming more and more common. At present, preprint technology has been widely used abroad. The so-called "pre print" refers to the printing of face paper (roll to roll) before the production of corrugated board, and then the printed face paper is sent to the corrugated board machine for veneering and cardboard production. The technological process adopted for "pre printing" is roughly:

face paper (WEB) printing - cardboard production - die cutting and slotting - Nailing box/gluing box

in comparison, some people call the commonly used corrugated cardboard printing process "post-print"

pre printing has some obvious advantages over post printing:

1. Higher printing quality and wider adaptability can be obtained.

pre printing uses satellite flexographic printing machine to print on the smooth paper surface. Compared with post printing using the uneven paper board surface of unit printing machine, it can print at a richer level, and the printing quality will be more stable and reliable

2. The corrugated box can obtain the highest strength

because pre printing does not need to imprint the paperboard after it is formed, it may avoid corrugating deformation and paperboard strength weakening. After printing, each color of printing will make the paperboard more or less deformed. Moreover, the more the number of printing colors, the greater the influence on the deformation of corrugated and paperboard

3. Higher production efficiency, convenient for production management

satellite flexographic printing machine is used for pre printing, and the common printing speed has reached 250 m/min or 300 m/min. although at present, the post corrugated board printing machine can also reach a considerable speed, the adjustment and auxiliary time of the pre printing machine, the scrap rate, and the failure downtime rate are significantly less than those of the post printing machine

pre printing has become an important trend of corrugated board printing, especially the printing of high-end cartons (including large and heavy cartons)

II. Performance and technical specifications of corrugated board prepress

1. The structure of the prepress, standard configuration and optional configuration

the layout of the prepress for corrugated paper is shown in the attached drawings on page 189. From the layout, it can be seen that the main components of the prepress include: unwinding part, input part, printing part, drying part, output part and rewinding part, as well as control part and auxiliary equipment. Prepress machines of different specifications have the same basic configuration and structure, which some people call standard performance. The standard configuration of pre printing machine mainly includes:

(1) high precision base, steel frame structure and common central impression cylinder of all printing units

(2) unwinding and rewinding mechanism

(3) input tension control unit

(4) input deviation correction device

(5) automatic meshing mechanism between the embossing cylinder gear and the printing unit

(6) automatic motor positioning system of printing unit

(7) laser engraved ceramic roller

(8) closed reverse doctor blade system

(9) pre register the meshing system

(10) sequential clutch and pressing mechanism of corrugated roller and plate roller

(11) closed loop temperature control system of central imprinting cylinder

(12) registration printing at high speed

(13) taper tension control mode

(14) inter color drying and Bridge final drying

(15) cooling drum assembly

(16) output tension control unit

the difference of pre printing mechanism is mainly determined by its selected structure and configuration. Common optional configurations include:

(1) printing machine management information system or digital control system

(2) print parameter storage and recall function

(3) high speed automatic unwinding and winding transfer paper (flying split) device

(4) far infrared drying system

(5) UV curing unit

(6) prepress and Postpress online processing units

(7) tape image observation system

(8) automatic ink fountain cleaning device

(9) UV ink printing unit

(10) robot that automatically loads/unloads paper rolls