Rubber Roller Making Machine Manufacturer

Jinan Power Roller Equipment Co., Ltd.

How to eliminate the occurrence of ink roller flying


Release time:

2018-06-15

When the ink is transferred, at the ink roller touching each other, the fiber is in two or more places, and when it is blocked or elongated, a fragment occurs, and it becomes spherical due to the external tension. At this moment, the electric double layer existing at the interface between the fiber and the fragment is destroyed, part of it remains in the ink, and the other part escapes to the atmosphere with the opposite charge. When the fiber is shortened, the residual charge in the ink is gradually piled up on the ink roller and the surface of the paper. Because the fragment has the same electric charge as the ink, when it approaches the ink roller or paper, it is squeezed into the air to form flying ink.

1. The reason for the occurrence of ink roller flying ink
  
When the ink is transferred, at the ink roller touching each other, the fiber is in two or more places, and when it is blocked or elongated, a fragment occurs, and it becomes spherical due to the external tension. At this moment, the electric double layer existing at the interface between the fiber and the fragment is destroyed, part of it remains in the ink, and the other part escapes to the atmosphere with the opposite charge. When the fiber is shortened, the residual charge in the ink is gradually piled up on the ink roller and the surface of the paper. Because the fragment has the same electric charge as the ink, when it approaches the ink roller or paper, it is squeezed into the air to form flying ink.
  
When high-speed machine uses high-speed viscous ink, low-quality binder, it is easy to make the ink rotate in the ink roller, pull the filament to produce a severe flying ink scene, so different types of printers need to select the corresponding ink to match.
  
2. Factors that affect flying ink
  
(1) The ink viscosity is too large, the ink is elongated at the outlet of the ink roller, easy to fly ink, together with the formation of uneven ink transfer, so that the paper plucking and powdering, the paper is difficult to peel off from the blanket, easy to flower, drop plate, etc.; The viscosity is too small, the ink layer is not cut safely, easy to fly ink, together easy to emulsify the ink, floating dirty, paste, dots expanded, affecting the quality of printing products.
  
(2) The thicker the ink layer on the ink roller, the larger the flying ink. When proofing on coated paper, when the thickness of the ink layer is 1.2μm, the ink on the plate only needs to reach 2.8g/m2; However, printing on offset paper, the ink on the plate must reach at least 4g/m2. When encountering the poor adhesion of paper properties to the ink, it is easy to form ink rollers to pile ink, and then fly ink occurs.
  
(3) When the appearance of the ink roller is uneven and the surface is dry and cracked, part of the ink layer is thickened, the amount of ink fog increases, and flying ink is easy to occur.
  
(4) The printing speed is increased, and the flying ink is increased.
  
(5) The relative humidity of the air is small, and the occurrence of flying ink is promoted; When the humidity increases, the charge is reduced and the amount of flying ink decreases.
  
If there is too much dampening solution in the ink, a severe W/O type emulsified ink is formed, the viscosity drops sharply, the ink filament becomes shorter, and a severe flying ink scene will occur. At the same time, the dampening solution immersed in the ink will also corrode the metal ink roller, form a hydrophilic layer on the surface of the ink roller and squeeze out the ink, forming the metal ink roller deinking.
  
(7) The binder of high molecular weight ink is simply drawn into filaments when the ink is cut, and flying ink occurs.
  
3. How to remove flying ink
  
(1) Choose excellent alcohol-resistant inks to make them accustomed to high-speed printing.
  
(2) Remove the rubber roller regularly and clean it all, so that the ink layer of the ink roller is uniform and the ink transfer performance is improved.
  
(3) The alcohol concentration is controlled between 10%-15%, too low or too high is not suitable.
  
(4) The amount of water bucket liquid should not be too large, otherwise the formation of ink filament will become shorter and obscure printing.
  
(5) When the electrolyte is added in the ink, the flying ink will be reduced, and with the participation of the electrolyte, the conductivity will increase, and the flying ink scene will be completely missing.
  
In short, the flying ink phenomenon may occur at any time due to the touch rotation of the two rollers during the printing process, requiring the operator not only to have a high-skilled operation level, but also to understand the data and standards involved in printing at a glance, and reduce the probability of flying ink as much as possible