1, there is a certain error in the overprint of the printing plate, which is not solid, and its flatness and compressive strength are relatively poor.
To some extent, the hardness and accuracy of the printing plates used in letterpress printing affect the printing accuracy of the products. If the traditional plywood is used to act as the plate of large face plate printing, the compression function of the plywood is very poor because of the short evenness and fastness of the plywood. In the process of printing, it must be disproportionate due to the uneven pressure or the true and false bottom, which makes the print print out of the layout and form the print. More than the internship version.
Two, improper ink adjustment, too high ink viscosity, resulting in instability of pre printing position。
Adhering to the proper viscosity of ink is an important condition for printing and ensuring the quality of printed products. However, ink viscosity is not standardized, nor can it unify a specification. Printing should be printed on the basis of the characteristics of the printed material, print the layout of the layout, and adjust the stickiness of the ink according to the experience to prevent this defect from happening, and print the plate with a large amount of ink absorption. It can take part in the appropriate adhesive or ink transfer oil according to the viscosity of the ink, which can reduce the adhesive force to the printing ink and guarantee the beating of the ink. Printing precision.
Three. There are errors and defects in the printing location caused by the maladjustment of the rollers.
Printing the field version, if the pressure of the roller is missing, then the paper in the embossing will simply slip outward from the teeth。 This is because the ink is sticky and has a certain degree of resistance to printing。 For example, sometimes, after the opening of the press, the bite of the tooth is closed, and the end of the press will have a trace of a trace。
Four. The printing pressure has been adjusted to the Ambassador
From the slip of the bite of the tooth, the inaccurate printing pressure is the essential factor for the uniform transfer of the imprint, and the ideal printing ink layer is derived from the moderately balanced printing pressure. Generally speaking, the surface of the substrate is rough, the printing area is large, and the printing pressure has to be increased correspondingly.
This is because the printing pressure has passed through the assembly to make the printing press deformed, causing the print print to appear in a large image, causing the inaccuracy of the printing。 On the other hand, the printing pressure is too big。 When the press is impress, it must press the press on the press on the roller, causing the press to slip from the teeth in the teeth。 The moment is unstable, and there is a small situation in order to prevent this bad result。 The pressure adjustment of the print print should be gradually pressurized by light and heavy in the case of the normal print of the plate, so that the talent is more accurately adjusted to the proper printing pressure, and then the printing quality is guaranteed。
Five. Ensure the printing technology of the package and prevent printing distortion.
The packaging and printing lining of Ji'nan is the bridge for the printing of finished prints and has a certain influence on the printing accuracy. Because of the difference in equipment planning, there is also a different demand for the thickness of the lining. If the thickness of the lining is not enough, the vertical standard of the layout is generally less than the corresponding plate length. If the thickness of the package is overstepping the parameter of the equipment, the printed page is larger than the plate practice amplitude. This is an essential factor affecting the printing accuracy.