The key factor affecting the quality of printing plates is the hardness of the printing plate. The higher the hardness, the smaller the elasticity of the printing plate. The service life of the printing plate is shorter, the clarity of the graphic and text dots is higher, and the deformation of the dots under pressure is small. However, due to the excessive pressure, the corrugated support is damaged to varying degrees, resulting in a decrease in the compressive strength of the cardboard box. The lower the hardness of the printing plate, the greater the elasticity of the printing plate. The printing plate has good printing resistance, longer service life, and can fully contact the rough printing surface, Make the printed product fully inked, but the large deformation of the dot affects the quality of the printed product. Therefore, choosing the plate material and hardness is the guarantee of quality.
In flexographic printing, solid photosensitive resin plates should be selected, which have good ink transfer performance and large tolerance. The advantages of high reproduction accuracy, good stability, wear resistance and deformation resistance, long service life, and convenient processing have been widely used. The hardness of the plate material should be selected according to different printing processes and the hardness requirements of different graphics and texts. The hardness of the actual and line printing plates should be at HS32-35, and the hardness of the small font and dot printing plates should be at HS37-42.