Troubleshooting:
1. Oxidation film on rubber roller
Due to the long-term diffusion and migration of the desiccant in the resin ink on the surface of the rubber roller, the roller surface is closed to form an oxidized film, which affects the ink absorption and ink transfer effect of the rubber roller. The removal method is generally to use manual or mechanical film tying, or to scrub with a 20% sodium hydroxide aqueous solution, and then neutralize with a weak acid or wash with clean water, but organic solvents such as ketones and esters cannot be used to clean the film, which will destroy the rubber layer on the roller surface.
2. Deinking of rubber roller
Due to the emulsification of ink, a hydrophilic base is formed on the smooth rubber roller to deink it. The solution is to remove the emulsified ink, clean the roller surface with a special cleaning agent, and use a 5% sodium hydroxide aqueous solution and pumice powder, mixed and polished to clean the roller surface.
3. Rubber roller slag
The long-term use and aging of the rubber roller, coupled with the erosion of ink and other chemicals, can easily cause the rubber roller to rot and slag, which will affect the ink transfer and printing quality. The surface rotten or cracked rubber layer must be ground off.
The following are the failures of rubber rollers and their troubleshooting measures
●Phenomenon: Small cracks appear on the entire rubber surface.
Cause: The roller pressure is too high or it is stored for a long time under inappropriate conditions.
Measures: Reduce the pressure and immediately grind out a new front rubber surface.
●Phenomenon: Deep cracks appear on the entire rubber surface.
Cause: Small cracks appear without grinding, and are aged by ozone and thermal oxygen.
Measures: Grind out a new rubber surface for mild cracks, and replace new rubber for severe cracks.
●Phenomenon: Local cracks appear.
Cause: Uneven roller pressure.
Measures: Adjust the roller pressure to make it uniform.
●Phenomenon: The rubber layer at both ends peels off from the metal core.
Cause: Abnormal heating occurs.
Measures: Find the heating location and cause, so that it does not heat up anymore.
●Phenomenon: The entire rubber surface peels off.
Cause: The roller pressure is too high.
Measures: Readjust the pressure.
●Phenomenon: The rubber surface becomes flat.
Cause: The pressure is not removed when the machine is stopped or the rubber roller is placed directly on the floor.
Measures: The rubber roller is idling to correct the deformation, and the grinding that cannot be corrected.
●Phenomenon: The rubber surface is hardened.
Cause: Long-term unreasonable storage and incomplete cleaning, adhesion of hardened ink and long-term use cause rubber aging.
Measures: Grind, even after grinding, it cannot be used, replace new rubber.
●Phenomenon: The rubber surface is softened.
Cause: Soaked in medicine, especially softened by organic solvents.
Measures: Grind, even after grinding, it cannot be used, replace new rubber roller.
●Phenomenon: The entire rubber surface is found to be uneven.
Cause: The result of chemical solvent erosion.
Measures: Grind or replace new rubber.
●Phenomenon: The local unevenness of the rubber surface.
Cause: Excessive pressure, the rubber layer and the metal core are peeled off.
Measures: Replace new rubber roller.
●Phenomenon: The roller body is not round.
Cause: Deformation caused by long-term wear and tear and excessive extrusion time.
Measures: Grind to make it round again.

★Storage and maintenance:
1. Storage environment
①During transportation and storage, the rubber roller should be kept away from direct sunlight, rain and snow, and should not be in contact with acids, alkalis, oils and organic solvents, and should be kept 2m away from heat sources.
②The rubber roller should be stored in a warehouse with a temperature of 10~35℃ and a corresponding humidity of 50~80%.
If the temperature is too high or too low, the rubber surface will age, crack, harden, and become inelastic, resulting in poor wear resistance.
If the temperature is too high, the roller core will absorb moisture and rust.
③Take measures such as covering the roller with thick paper and ink plastic cloth to avoid light. Do not place it under strong light and ultraviolet rays, otherwise it will cause the rubber surface to age, discolor, crack, etc., reduce the service life of the rubber roller and affect the quality of printed products.
2. Storage method
When storing the rubber roller, the shaft should be supported for storage. It is strictly forbidden to squeeze and stack. The distance between the rollers should not be less than 5mm.
3. Precautions
① When transporting and moving, the shaft must be lifted and hoisted to prevent the rubber surface from being knocked, bumped, or scratched.
② If the new roller is not used temporarily, please do not remove the wrapping paper, which can play a protective role.
③ For rubber rollers that have been stored for an extended period of time, check that there is no problem with the rubber roller before using it on the machine.

★ Use and maintenance:
1. Before printing
Check whether there are foreign objects between the rollers, whether the rubber rollers are intact, whether the pressure between the rollers is uniform, and confirm that it is normal. After cleaning and cleaning, printing can be carried out.
2. During printing
The rubber roller should always maintain a good contact state during operation and the force should be uniform. Regardless of the width of the printed product, the entire rubber surface of the rubber roller should be lubricated with ink oil; depending on the amount of ink accumulated between the rubber rollers, the amount of ink should be adjusted in time to ensure the printing quality.
Under the premise of ensuring the printing speed, in order to prevent the ink from drying too quickly, the viscosity of the rubber roller is reduced, and the surface is crusted, the amount of drying oil should be controlled for the ink that needs to be added to prevent the rubber roller from not inking and uneven ink transfer during operation.
3. After printing
The rollers and the rollers should be separated from the printing in time, the load pressure should be removed, and the rubber surface should be prevented from being deformed by static pressure. It is necessary to clean the residual ink on the surface of the rubber roller in time to prevent the ink blocks, ink films, ink feces and dirt from floating on the rubber surface due to drying (especially the ink blocks on the two ends of the nylon roller). When running again, it will crush and damage the smoothness of the rubber surface, and in severe cases, it will cause pitting and slag.
4. Rubber roller cleaning
The rubber roller must be cleaned with a special cleaning agent before and after printing to keep the surface of the rubber roller smooth and ready for use.
If the cleaning is not timely, the ink will adhere to the micropores through the fluffy micropores on the surface of the rubber roller, and paper hair and dirt will adhere to the surface of the rubber roller. If the parking time is too long, the ink conjunctiva will cause the contact surface of the two rollers to adhere, and the rubber surface will be torn when driving again, making the rubber roller scrapped.
If the cleaning is not in place, glazing will occur, resulting in reduced ink affinity and ink transfer, and even deinking. Glazing increases the hardness and elasticity of the rubber roller surface, and accelerates the wear of the rubber roller, resulting in pitting and cracking on the rubber surface, causing slag, affecting the printing quality.
Note: Glazing refers to the phenomenon that the surface of the rubber roller hardens and becomes mirror-like.
5. Requirements for cleaning agents
① Non-flammable, safe and reliable, and non-polluting to the environment.
② Good washing ability for ink.
③ No corrosion to the rubber roller and no deformation of the rubber surface.
④ Use a special cleaning agent for "UV ink" for UV ink rubber rollers.
⑤ Use a special cleaning agent for "alcohol dampening rollers" for alcohol dampening rollers.
6. Cleaning method
You can start the machine and spray the cleaning agent on the ink roller.

★Installation and debugging
1. Loading and unloading
When installing the rubber roller, the shaft head and bearing must be matched to ensure a certain degree of accuracy and cleanliness. The roller should be handled with care and should not collide with the shaft head and rubber layer to avoid damage to the roller body, bending, and damage to the rubber layer.
2. Lubrication
The shaft head and bearing of the rubber roller should always be effectively lubricated. If the lubrication is poor, it will cause wear and tear of the shaft head and bearing of the rubber roller, increase the gap, and even cause uneven ink printing. At the same time, printing bar marks will also be caused by adverse conditions such as rubber roller jumping and sliding. If there is no effective lubrication during long-term continuous operation, it will also cause heat generation of the bearing and the shaft core, causing the rubber surface at both ends of the rubber roller to expand due to heat and wear, resulting in pockmarks, glue loss, and cracks on the rubber surface at both ends.
3. Debugging
The pressure between the rubber roller and the rubber roller and the printing should be adjusted appropriately according to the elasticity, hardness of the rubber and its role in the printing process. Generally, a 0.15~0.20mm feeler gauge (the feeler gauge should be lubricated to avoid damaging the rubber surface) is used for testing. The radial contact pressure of the rubber roller must be uniform. Otherwise, long-term operation will cause the rubber roller on the side with higher pressure to become rough, lose glue, crack, and debond.