How to troubleshoot rubber roller in printing?

 

How to troubleshoot rubber roller in printing?

 

Printing failures caused by equipment material quality problems in the printing process are common. Rubber rollers are an indispensable accessory for offset printing machines and have a great influence on printing quality. The author encountered two failures caused by the quality of the rubber roller during the printing process. I will share the elimination process with you and summarize how to use the rubber roller correctly.

 

Fault performance: During the printing process, the cyan group began to have normal color and then slowly became shallower.JCTPRINT

 

Troubleshooting process:

 

1 Stop the ink on the printing plate (a common method of viewing the pressure, using the roller to press the surface of the printing plate, the width of the ink mark on the surface of the printing plate can indicate the pressure), and found that the pressure of the water roller is large, the width of the ink mark About 9 mm, so the pressure was adjusted to normal, and then the machine was started. It was found that there was a paste phenomenon at the plate mouth, and the dirty surface on the plate was more serious. The phenomenon of sudden large water and small water repeated, the plate water supply was unstable.

 

2 When the machine stops, it is found that there are water drops on the printing plate tip and the blanket tip, so the pressure of the metering roller and the water roller are checked and adjusted to the normal state, the water supply is normal, and the fault is eliminated. JCTPRINT

 

3 Jog the machine and burn the ink on the plate. It is found that the pressure of the plate roller just adjusted has become larger, and the nut that adjusts the pressure of the plate roller is not loose. We tried to jog the machine several times and found that the pressure of the plate roller was different every time.

 

4 All the water rollers of the plate were removed, and the surface of the removed rubber roller was found to be flat and without wear.The bearings at both ends were taken down and carefully observed, and it was found that the sleeves at both ends of the rubber roller were eccentric.JCTPRINT

 

 

 

So we came to the conclusion:

 

The sleeve of the rubber roller is eccentric, which causes the pressure of the different circumferential positions to be different when the water roller on the printing plate is installed. The pressure at the position of the rubber layer is large, if the pressure is according to this position. Adjusting, the pressure of the thin layer of the rubber layer will be smaller, which will easily lead to the paste and the upper surface of the glue. On the contrary, the ink is pressed according to the position of the thin layer of the rubber layer. When the pressure is adjusted, the pressure of the entire water roller will be pressed. Larger, printing will appear more and more light, and the pressure on the plate roller will be too large and small, the plate supply is always unstable. When we replaced the new, good quality version of the water roller, the fault disappeared. The reason for the failure was that the quality of the rubber roller was too poor, and the materials department and the printing workshop did not carefully accept it. The rubber roller with poor quality was applied to the printing, which led to the failure.

 

More information please contact with us :JCTPRINT