Printing News
Cause the fluctuation of the longitudinal several reasons

1. Electrical fault from overprint fluctuations
Generally speaking, gravure machine alignment of the electrical system of it is a part, processing device by testing and actuators form. Any link didn't work properly, are likely to cause overprint fluctuations. So, to analyze the reason of the longitudinal wave, must be familiar with overprint system electrical principle.
Here in France ATN company gravure production line as an example, the principle of the longitudinal electric analysis.
In all kinds of printing unit, the printing plate cylinder every turn around, they produce a pulse, it and the printing unit produced by the 500 pulse coder together into coding circuit board. Through the coding circuit board processing, forming 4 pulse, and was sent to the longitudinal (or horizontal) alignment circuit board. Here, the four pulse signal detection and cursor on the printed matter from a pulse signal is more, if the overprint deviation, alignment circuit board will output a about 5 v voltage into the PLC. The PLC after treatment, then to the stepping motor drive, and promote the stepping motor action, to achieve the purpose of alignment adjustment.
Check caused by electrical fault longitudinal wave, general is to take ShunTengMoGua method. In understanding overprint electrical system based on the theory of check the relevant electric step-down original is normal and circuit was clear. But to adjust a specific type of alignment gravure machine has quite experience, also can adopt jumping way of thinking, this can find out the fault point more quickly.
2. Mechanical fault from overprint fluctuations
From the practice experience, the mechanical system of longitudinal inspection, there are no fixed method. Only the gravure machine mechanical parts to understand and master, what are known as the mechanical structure will influence of overprint, as soon as possible to find the problem. Of course, due to mechanical failure "appearance" general than electrical fault "appearance" obvious, therefore, to find the cause of the wave is also easier overprint.
For example, stamping roller after long-term use, the surface will appear more obvious wear trace, will affect overprint precision. The thin print content, the greater is the impact on the accuracy of the longitudinal. In addition, if observed stamping roller in printing process keeps up and down in vibration, it may very well be stamped roller bearing damage, the printing products of longitudinal alignment will have an impact.
Be like again, not the printing plate cylinder lock, there will be little channeling move, often caused transverse and longitudinal appear beat. In addition, the paper roll horizontal channeling move, stepping motor drive part of the problem and so on, also can cause overprint fluctuations. And, this kind of overprint fault, its expression basically is in the process of production are shown relatively substantially, sudden overprint beating.
3. Other factors cause overprint fluctuations
In addition to electrical and mechanical reasons, and the others are caused by the fluctuation overprint also nots allow to ignore.
First of all, improper operation can cause overprint fluctuations. For example, force the setting is appropriate, the equipment in high speed running, the paper tape will suddenly loose and tight, influence vertical alignment. Be like again, the oven temperature set too high and could cause the paper through the oven deformation is too large, under the influence of the color of the overprint.
Secondly, raw materials and production environment on overprint may also be affected. Paper is too loose the actual tension changes frequently, increase operation difficulty, in the most was not in longitudinal longitudinal; The paper will make the edges in leading paper system kept action, transverse overprint influence. The production environment humidity and temperature condition, the paper in printing process to the deformation size a certain effect.

(Gold Printing Group)
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