High quality rubber roller should have the characteristics

The surface of the high quality rubber roller should be fine, smooth, slightly sticky and have good ink transfer performance. In the production, the rubber roller is affected by the fountain solution, ink, paper and other factors for a long time, and each cleaning cannot be very thorough. The residual impurities accumulate on the surface of the rubber roller layer by layer. As time passes, the surface of the roller roller will be closed. The capillary pores form a smooth crystalline layer that resembles calcium, which severely affects the properties of ink transfer and water transfer, and it is not possible to control the ink color stably. In this regard, after each washing with car washes, it was washed with some citric acid water again to cause some calcium impurities on the surface of the rubber roll to react chemically to form easily soluble substances for cleaning.

The surface of the rubber roll is easy to have scars and juts

Because the rubber roller is relatively soft, some hard objects will be scratched during the high-speed operation. In particular, the alcohol dampening solution relies on the plate roller. Once scratches occur, it cannot be used again. In order to avoid such failures, one is to check whether the printing plate is tightened or clamped, resulting in cracks and cracks in the printing plate at the tip of the printing plate. The second is to see if the maintenance of the ink roller is not timely. The accumulation of impurities such as inkskin and ink residue accelerates the friction, heat, and aging of the rubber roller, causing the surface of the rubber roller to be filled with blindness. Generally, two rollers are more serious.

Rubber roller premature cracking, aging

There are many reasons, such as the excessive dry oil in the ink, which causes the ink to dry on the rubber roller; the cleaning agent used to clean the rubber roller is improperly selected, the cleaning time is too short, and the impurities on the roller can not be thoroughly cleaned; the ambient temperature of the workshop High, dampening cooling system is not working well, large amount of heat generated during operation of the rubber roller can not be distributed in time, the internal temperature of the rubber roller is high, the roller bearing performance is not good, and it is rotated by the ink stringer, resulting in beating friction, extrusion, etc. .

Deinking

In the offset printing operation, ink is emulsified due to "great ink and large ink", and a hydrophilic base is formed on the smooth roller, and deinking occurs. The solution is to remove the emulsion ink, wash the deinking roller with gasoline, mix the surface with talc powder with 5% sodium hydroxide solution, remove the hydrophilic layer, and restore the ink roller to its oleophilic character. At the same time, the metal roller (or hard roller) is also treated accordingly. The hard roller can also be sanded with fine sand in the water-spraying state. It cannot be fixed in the same position, otherwise it will damage the rubber roller. The fundamental method is to control the p H value of the water fountain solution, do a good job of ink balance, and reduce the degree of ink emulsification.

maintenance

Whether the maintenance of the ink roller is reasonable and in place has a direct impact on the service life and printing quality of the ink roller.

Regular maintenance

After the end of each printing, the remaining ink, paper powder, and paper hair on the rubber roller should be cleaned. Special attention should be paid to cleaning and wiping the residues of the two rollers to avoid long-term accumulation of residue and aging of the rubber roller. . Among them, the cleaning agent must use the specified chemical reagents, must not use corrosive solvents; wipe cloth is best to use knitted fabric to prevent cotton wool residue.

Check if the bearings on both ends of the rubber roller are free and the condition is good. If there is any looseness or wear, it must be fastened or replaced in time. When the bearings of the rubber roller are damaged to a certain extent, they will generate jumping friction and squeezing, shorten the service life of the rubber roller, and cause the printed product to appear as "ink/pump." Take off the rubber roller every week, butter the bearing, replace the bearing with serious wear and poor rotation, and ensure the normal use of the rubber roller.

Look at the rubber surface of the rubber roller is good, especially the plate roller must be selected the best. Cracks on the surface and more juts are required to re-sharpen and replace them in time.

2. Multi-color group rotation maintenance

In the weekly maintenance, it is difficult to thoroughly maintain the multicolor platform offset press or rotary press. Under the premise of normal daily maintenance, the maintenance of the month and the maintenance of six months can be carried out according to the structural features of the multiple color units of the equipment. The project is decomposed to every week, and one printing unit is mainly maintained every week. This method is also adopted for the maintenance of the rubber roller of each color group. Every week, it inspects and maintains all the ink rollers of a color group unit, focusing on checking whether the rubber roller is calcified, whether the bearings are short of oil, and whether the pressure between the rubber rollers needs to be adjusted.

Within one month, all units of the unit roll can be rotated at least once. The machine is operating normally for about six months, and then check the maintenance manual for any missing items.

When the color group rotates and maintains, the personnel should divide the work rationally, cooperate with each other to tacit understanding, the movement should be regulated, various tools and cleaning agents should be selected properly. Neither sharp tools can be used to scrape off the rollers and rollers, nor can they use reducing agents and bananas. Water cleaning roller, etc.; also make a detailed record, including the main parts of maintenance, maintenance methods, hidden dangers, maintenance programs. Under special circumstances, work that cannot be completed this week should be scheduled in the next week's maintenance schedule to ensure that the parts to be maintained are implemented one by one.