Gravure machine electrostatic ink transfer device selection guide
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
The electrostatic ink transfer device consists of an electrostatic pressure roller. Conductive aluminum roller (or conductive brush), control cabinet (including high-voltage electrostatic generator) and other components.
It generates high voltage and low current through the control cabinet, and the current is transmitted to the electrostatic pressure roller through the conductive aluminum roller or the conductive brush, so that the electrostatic pressure roller is charged with a positive (or negative) charge, so that the electrostatic pressure roller is in contact with the paper. A high voltage electrostatic region is created between a conductive surface, paper, and gravure plate. Under the action of static electricity, the ink in the gravure plate is sucked out and uniformly transferred to the surface of the paper so that the transfer rate of the ink reaches or approaches 100%.
In the electrostatic loading process, it is necessary to select a positive or negative charge depending on the color of the ink, the composition of the ink, and the positive and negative of the electrostatic charge on the surface of the paper.
Matters needing attention when selecting an electrostatic ink moving device
1. The first is the choice of manufacturers of electrostatic ink transfer devices.
2. After the manufacturer selects, it is necessary to determine some parameters of the device and auxiliary facilities, such as the way of electrostatic loading, electrostatic pressure roller, the width of the printing machine, the width of the printed product, and so on.
(1) There are two main types of electrostatic loading, namely aluminum rollers and electrostatic brushes. These two methods have their own shortcomings, such as: there is a gap between the aluminum roller when loading and the electrostatic pressure roller; the brush is easy to wear and deform when the brush is loaded, which will cause uneven electrostatic loading.
(2) When selecting an electrostatic pressure roller, distinguish it from the pressure roller. The surface of the electrostatic pressure roller must be electrically conductive. The hardness and pressure roller should also be different. The hardness of the general pressure roller should reach HS90, and the hardness of the electrostatic pressure roller should be controlled according to the different equipment in HS80-85. It is too soft and easy to cause wear. , poor durability; too hard and easy to cause ink transfer is not complete, the static effect is not obvious.
(3) The width of the printing press and the width of the printed product should be considered together to solve the fabrication of the electrostatic pressure roller and the length of the conductive portion. In the past, the length of the electrostatic pressure roller was the length of the conductive portion, which easily caused the paper to break, or the paper edge was broken and could not be used on the machine. The length direction of the electrostatic pressure roller is now divided into a conductive portion and an insulating portion, just as with a pressure roller.
Matters needing attention in the use of electrostatic ink transfer device
Since the electrostatic ink transfer device is mainly used when the printing mesh is adjusted, the electrostatic pressure roller should be installed every time to re-adjust the pressure, and the preparation time is long. In addition, in order to ensure better ink transfer and safety during printing, the following items must be observed.
1. Check the mounting position of the electrostatic pressure roller. The pressure of the pressure roller and the pressure at both ends of the pressure roller.
2. Check the mounting position of the conductive aluminum roller and the electrostatic brush and the wires connected to the static control cabinet.
3. Check the working status of the pressure switch or speed controller.
4. The loading of the electrostatic voltage should be carried out when the speed of the gravure printing machine reaches 30 m/min or more. The voltage is gradually increased from zero according to the improvement of the printing effect. If there is no obvious effect of increasing the voltage, the voltage should be stopped and changed. Load the polarity of the voltage or check for problems in time.
5. If the electrostatic transfer device is used, the mesh printing effect is not improved, and the surface flatness of the paper used and the engraving quality of the plate hole should be checked.
Insufficient presence of electrostatic ink transfer devices
Since the range of electrostatic ink transfer devices used in China is relatively narrow, the research on this technology has just started. There are still some shortcomings in the domestically used devices, and it is hoped that the peers can learn from this.
1. The number of engraving lines of gravure mesh products can be up to 1 line/inch, which makes the degree of fineness of gravure cells very restricted, so the level of product is only improved by electrostatic ink transfer device. The level of sophistication is still difficult to meet the requirements.
2. Adding static electricity to the paper by the electrostatic pressure roller will result in a strong electrostatic area in the range of about 300mm away from the intaglio plate. Therefore, it is necessary to install a static elimination device in this part, otherwise it is easy to cause the electrostatic strength to cause the ink tank to ignite. . Although the fire phenomenon does not cause much damage, it has buried a safety hazard.
3. At present, the electrostatic ink transfer device still has a large disadvantage in printing gold and coated paper, and the printing quality is not significantly improved.