After observation, we found that when irregular "stripes" and uneven ink layers occur, the indoor humidity is relatively low. Therefore, our preliminary analysis believes that the cause of the above-mentioned undesirable phenomenon may be caused by static electricity. The principle of static electricity is due to the exchange of positive and negative ions in two different substances, that is, due to friction and rapid separation, the positive and negative charges are no longer in the original neutral state, and some charges will move between the two objects. At this time, static electricity is generated. In the production process of high-speed rotogravure printing, due to the large friction between the printing material and the printing equipment itself (such as: metal transmission roller, colloidal embossing roller), the generation of static electricity becomes inevitable.
In addition, due to the fast printing speed of the rotary gravure printing machine and the continuous operation process, there is a continuous friction process between the printing material and the device itself during the production process, and an electrostatic field is easily formed around the printing material. The contact area between the quality platen roller and the printing plate will be more prominent. With an induction test pen, the static electricity between the color groups is up to hundreds of volts. We further analyze and believe that due to the existence of the electrostatic field between the color groups and the uniformity of the equipment running direction, the end of the irregular "stripe" phenomenon must point in the opposite direction of the equipment operation, and due to the electrostatic field discharge, the ink layer is uneven The phenomenon also shows a distribution law related to the electrostatic field. For this reason, we further confirmed the irregular "stretch" phenomenon and the uneven sample of the product layer, which proves that the results of our analysis are correct.
In response to the analysis results, we conducted an indoor environment humidity adjustment test to keep the indoor humidity above 70%. Irregular "stripes" and uneven ink layers have been significantly improved. But this will cause another quality problem, that is, the product is easily deformed after the indoor humidity increases, and the cardboard substrate with strong water absorption is also very easy to affect the reduction effect due to moisture. To this end, we used a static elimination brush to carry out further static elimination tests. As a result, irregular "pulling" and unevenness of the ink layer completely disappeared, and the voltage was measured with an induction test pen, and the measured voltage value was close to zero.
For this reason, we determined that the irregular "drawings" and unevenness of the ink layer that affect the printing quality are due to the generation of printing static electricity. The use of static elimination brushes to eliminate static electricity can not only effectively eliminate irregular "drawings" and ink layers Uneven faults and low investment costs. In addition, the effective elimination of printed static electricity can also eliminate some hidden safety hazards caused by static electricity.Art Easel,Flipchart Easel,Easel Stand,Mobile Flipchart
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