1. Offset printing process

The offset printing process includes multi-color groups, multifunctional roll paper and flat paper models. It is suitable for printing pre printed cardboard boxes with large production batches and relatively fixed product structures. After the surface paper is printed, it can be directly mounted and bonded with corrugated cardboard on the corrugated production line. The printing speed of the latter can reach about 10000 sheets per hour, which is suitable for printing small and medium-sized cardboard products. The printing specifications of the surface paper can be flexible and varied. The flat paper machine can also directly print fine corrugated cardboard, and its printing accuracy is higher than the former, with relatively stable quality. The offset printing process is suitable for printing fine line plates and multi-color mesh plates with thin ink layers, which are stacked or overprinted. It has the advantages of high dot resolution, rich printing layers, clear tone boundaries, soft color tones, good printing reproduction results, convenient and fast plate production, easy installation and calibration, and low plate making costs. It is widely used for printing black pre printed cardboard boxes.
2. Flexographic printing process
Flexographic printing technology can also be divided into roll paper and flat paper multi-color printing machines. Flat paper printing machines have pre printing models for printing surface paper, as well as units that can directly print corrugated cardboard and complete slitting, creasing, and slotting online. The flexographic printing process is compatible with the advantages of relief, planographic, and gravure printing processes. Due to the flexibility of the printing plate, the printing pressure is much lighter than other processes, and it has the main characteristics of light printing pressure, thick printing ink, clear imprint, and high plate durability. This process can print cardboard with both good surface gloss and rough surface; It can print both non absorbent materials and highly absorbent cardboard; Can print both thin and thick paper; It is suitable for printing fine mesh plates and line plates, as well as for printing spot color line plates or solid plates. Flexographic printing plates are divided into rubber plates and resin plates, with rubber plates mainly made of natural rubber and synthetic rubber. There are three types of plate making: manual carving, laser carving, and casting plate making. When using rubber plates, attention should be paid to their printing suitability, such as considering the ink affinity, ink transmission, coverage, and reproducibility of rubber. When using water-based ink for printing, natural rubber plates are better than synthetic rubber plates.