Troubles And Causes Of Common Rubber Rollers Such As Printing Rubber Rollers

1. Thermal aging
Heating of the rubber roller will accelerate the desulfurization, cause thermal aging, make the surface sticky, soft, and even cracks into orange patterns. The rubber roller can only be replaced at this time.

2. Gel drop
The ink dries early during the transfer process of the colloidal surface, and the dried ink film decreases due to its ductility. During the rolling process, the colloidal surface will be destroyed with the cracking of the ink film, causing the colloid to fall off. The main reason for the early drying of the ink is the addition of a desiccant to the ink, the printing of inks with faster drying properties (such as POP ink for aluminum foil paper), and the failure to clean the ink roller as required, which makes the ink in the process of long-term use. Drying occurred on the rubber roller.

If the temperature is too high during the process of roller processing, the surface is easy to be carbonized, and the phenomenon of blocking will appear in short-term printing.

Excessive printing pressure adjustment, when the machine is idling, if the idling protection measures are improper or not timely, it will also accelerate the damage of the roller surface.

Solution: The rubber roller that has dropped blocks can be replaced to solve the printing failure caused by this.

3. Surface glazing
In the printing process, the organic and inorganic substances in the binder in the ink, the hydrophilic colloid in the fountain solution, the shed filler in the paper, and the paint will form a "bright film" on the surface of the ink roller, making the ink roller The surface is vitrified and the ink transfer performance decreases.

4. The surface of the rubber roller produces crystalline compounds
5. Rubber roller expansion
In addition to the heat, the main reason is the use of improper cleaning agents, causing the colloid to swell.

Solution: Choose an appropriate cleaning agent. (Organic solvents that often swell rubber rollers: MEK methyl acetaldehyde ketone, trichloroethylene, acetone, cyclomethane, banana water; non-swelling organic solvents: alcohol, kerosene, light oil, roller cleaning agent)

6. Circumferential streaks: In addition to the similar circumferential streaks caused by crystalline compounds, the dry ink skin on the hard ink roller, and the garbage will scratch the surface of the soft rubber roller during operation to form circumferential stripes. mark. At this time, dead ink remover must be used to remove the dried ink skin.

7. Water fountain roller ink staining: the chromium roller surface can fully isolate the ink after absorbing the fountain solution, but excessive fountain solution and excessive acidity of the fountain solution will increase the emulsification of the ink, and the emulsified ink will follow The water return path returns to the water bucket roller. After the water bucket roller absorbs ink, it will cause poor dampening and local water failure. The ink on the water bucket roller must be removed in time. At the same time, adjust the amount of fountain solution and its composition.

8. Water splashing at both ends of the water roller: During the printing process, there are water droplets dripping on the printing surface of the substrate on both ends of the water roller. The reasons for this situation are: the length difference between the water bucket roller and the metering roller exceeds the allowable range. It is greater than 0.5mm; the corners of the water bucket roller are processed well, and the corner roundness is greater than 0.5mm.