How to differentiate offset print to produce medium double image phenomenon
From;    Author:Stand originally

Double image is finger mark brushs graph article week to surround occurrence profile or empty shadow, differ according to direction can divide for axial double image and Zhou Xiangchong shadow two kinds. Axial double image and line of drum shaft heart become lesser angle, zhou Xiangchong shadow and line of drum shaft heart are perpendicular. The account that breakdown of a few kinds of double image produces introduces below.

1. mackintosh stretchs tight incompactly, create full edition or local Zhouxiang double image, cent is two kinds of circumstances.

(1) mackintosh whole stretchs tight incompactly, cause mackintosh to be after press press cannot seasonable restoration, create integral double image.

(2) mackintosh is cut into parts cut or installation is askew, cause local stretch tight incompact and create local double image.

Right now, take up mackintosh or reinstall mackintosh to be able to solve a problem.

2. Platen pressure is too great, create integral Zhouxiang double image.

Should according to pressworking the ply of paper adjusts platen pressure.

3. Cross edition paper not to work, cause superstratum double image of ten pieces of paper, the direction of this kind of double image is not secured and the meeting is weaker and weaker.

4. Rough, water content all does not cause paper local double image, and the position is not fixed, do not have sometimes when, weight.

5. Forme is done not have taut or the both ends that hold a mouth bursts apart, create full page or local Zhouxiang double image.

6. Platen of embossing of double lubricious machine holds paper tooth to fill up under platen face, embossing platen holds a tooth to hold paper, paper is in of embossing platen after holding a mouth a paragraph cannot clingy platen, via embossing of monochromatic mackintosh hind, major arched disappears, still have a few arched after embossing of the 2nd kind of mackintosh, as a result of the minim difference of arched, the site print that cannot go up with monochromatic mackintosh sometimes accordingly overlaps completely, create double image thereby.

7. Embossing platen holds paper tooth power too small, inhomogenous, the tooth that hold paper and tooth mat wear away serious, too smooth, or capacity of monochromatic Chinese ink is much, viscosity is big, make paper mobile in the tooth that hold paper. Because mobile amount is different, the site that causes dichromatic mackintosh cannot coincide, and show double image.

8. Platen gear, bearing wears away, clearance greatens, when the machine when abrupt to load, platen produces double image because of shaking, additional, if platen bearing becomes loose, stop push bearing not locking also can create double image.

The reason that creates double image is very much, encounter double image problem, should analyse the type of double image above all, according to its the type searchs an account, remove trouble.





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