subject: Gravure Process Analysis Fluctuations Caused By Overlay [print this page] In the gravure process, the overprint frequent fluctuation, the impact of many factors, and difficult to detect, deal with them is difficult. This analysis only from the following aspects.
Print Network HC In the gravure process, the overprint frequent fluctuation, the impact of many factors, and difficult to detect, deal with them is difficult. This analysis only from the following aspects.
1. Electric Failure caused by fluctuations in overlay
General, Gravure printing machine -Alignment of the electrical parts are from the test section, treatment plants and implementing agencies composition. Any link is not working properly, may cause fluctuations overprint. Therefore, to analyze the reasons for fluctuations overlay, overprint systems must be familiar with electrical theory.
Following ATN's French gravure production line, for example, click on the overlay analysis of electrical principle.
In all colors Print Units, the plate cylinder with each turn, it generates a pulse, which, by the printing unit on the encoder produces 500 pulses with the access code circuit board. Processed through the encoder circuit board, forming four pulses, has been sent to the vertical (or horizontal) register circuit board. Here, the four pulse signals and the print on the cursor come a pulse signal comparison, if the deviation of the overlay at this time, the output register will be a board about 5 volts into PLC. The PLC treatment, then stepping motor driver, stepper motor so as to promote action to achieve the set of quasi-regulation purposes.
Inspection by the electrical fault caused the overlay fluctuations, the general approach is to take six steps. To understand the principle of electrical overlay systems based on the original level by level check whether the relevant electrical circuit is normal and smooth. However, regulating a specific set of criteria gravure models have gained considerable experience, they could leap to thinking, this can quickly find the point of failure.
2. Overprint caused by mechanical failure wave
From practical experience, on the overlay system of mechanical inspection, there is no fixed method. Only on the gravure press to understand and master the mechanical part, the well-known mechanical structure which will affect the overlay to find the crux of the problem as soon as possible. Of course, due to mechanical failure of the "show" than a general electrical failure of the "show" much more obvious, therefore, to find the resulting volatility is relatively easy to overlay.
Example, impression cylinder after long use, the surface will appear more obvious signs of wear, will affect the accuracy of the overlay. Thinner substrates, the greater the overlay accuracy. Also, if observed in the printing process, impression cylinder up and down constantly vibrating, it is likely a stamping roller bearing failure, which is printed in vertical register an impact.
Another example, plate cylinder is not secured, there will be small rocky ledge, often caused by a sudden horizontal overprint of beating. In addition, the guide roller horizontal traverse, stepping motor drive some problems and so on, also will lead to overprint fluctuations. Moreover, this type of overlay failure, its performance is basically the production process from time to time in the relatively large, sudden jumps in the overlay.
3. Overprint caused by factors other fluctuations
Addition to electrical and mechanical reasons, overprint caused by fluctuations in other areas can not be ignored.
First, improper operation will cause fluctuations overprint. For example, the tension settings are not appropriate for the size, the device in the high-speed operation, the tapes will suddenly loose suddenly tight, affecting vertical register. Again, set the oven temperature is too high, it may cause the media through the oven after the deformation is too large, affecting the next color overlay.
Second, raw materials and production environment also have an impact on the overlay. Paper tension is too loose will make the actual change frequently, increasing operational difficulties, mostly caused by the performance of overlay are not allowed in the vertical; irregular edge of the paper will wrap system stop action, affect the horizontal overprint. Production environment of temperature and humidity conditions, will paper the deformation in the size of the printing process has a certain influence.
In short, the impact of gravure overprint variety of reasons, the influence of different sizes. But if we look carefully, conscientiously sum up, we will be able to identify the crux of overlay are not allowed, so as to achieve rapid troubleshooting to ensure product quality purposes.
Gravure Process Analysis Fluctuations Caused By Overlay
