Section 2 Printing Out of Register
Out of register is one of the most common, typical malfunction when doing the printing, and accurate overprint is the primary indicator for the presswork should be achieved. We refer to the accurate overprint, is mean under the different printing conditions, the overprint error at different quality requirements presswork should be within the specified range. accurate overprint will big help improved the quality of printed matter.
Out of register is in the color printing process, the imprint overlap error exceeds the specified range .The three main manifestations are vertical out of register, horizontal out of register and vertical and horizontal at the same time out of register.
If you want to avoid misregister problem in printing, we first need to analyze the reasons for failure. In the lithographic offset printing, resulting in misregister printing fault is very complicated, but summarized mainly in the following aspects:
1.The improper adjustment and use of mechanical parts, which is mainly manifested in the leading or lagging on the printing sheet, the misalignment on printing rules adjust, feed edge more bite or less bite, both sides unequal.
2. Plate itself defects caused misregister, the original is not standard when in makeup and printing down or condition changes.
3. Rubber blanket deformation, paper deformation caused misregister (paper pressure deformation or stripping deformation).
4. Other factors changes caused by misregister, such as environmental temperature is not in conformity with the requirements, environment relative humidity is not in conformity with the requirements, etc.
5. The maintenance of the machine is also very critical, the gripper need most careful care, clean.
By analyzing the various reason that lead to printing out of register, we can use these analysis the results to avoid out of register in the actual printing process.