Introduction of various failure causes of rubber rollers

　　Introduction of various failure causes of rubber rollers

　　1. Crystallization and calcification on the surface of the rubber roller: The surface of the high-quality rubber roller should be fine and smooth, with a slightly sticky feel and good ink transfer performance. In production, the rubber roller is affected by factors such as fountain solution, ink and paper for a long time. In addition, each cleaning cannot be very thorough, and the remaining impurities accumulate on the surface of the rubber roller layer by layer. Over time, the original surface of the rubber roller will be closed. The capillary pores form a smooth crystalline layer similar to calcium, which seriously affects the ink transfer and water transfer performance, and cannot stably control the ink color of the printed matter. In this regard, you can wash with some citric acid water every time after washing with car wash water, so that some calcium impurities on the surface of the rubber roller will chemically react to form soluble substances for cleaning.

　　2. The surface of the rubber roller is prone to scratches and pockmarks: because the rubber roller is relatively soft, a little hard object will be scratched during high-speed operation, especially the alcohol fountain solution against the plate water roller. can no longer be used. In order to avoid such failures, one is to check whether the printing plate is tightened or the plate clamp is clamped, causing cracks and cracks at the tip of the printing plate to scratch the water roller and ink roller; the second is to see if the ink roller is not maintained in time. The accumulation of impurities such as ink skin and ink residues accelerates the friction, heat generation and aging of the rubber roller, making the surface of the rubber roller covered with pockmarks. This situation is generally more serious at both ends of the rubber roller.

　　3. Premature cracking and aging of the rubber roller: There are many reasons, such as excessive drying oil in the ink, which causes the ink to dry and heat on the rubber roller; the cleaning agent used for cleaning the rubber roller is not selected properly, the cleaning time is too hasty, and the Impurities cannot always be thoroughly cleaned; the ambient temperature of the workshop is high, the dampening cooling system is not working well, a lot of heat generated by the operation of the rubber roller cannot be dissipated in time, and the internal temperature of the rubber roller is high; As it rotates, it produces beating friction, squeezing, etc.

　　4. Deinking: In the offset printing operation, the ink is emulsified due to "big water and big ink", and a hydrophilic foundation is formed on the smooth rubber roller, which will cause deinking. The solution is to shovel off the emulsified ink, wash the deinking rubber roller with gasoline, mix the surface with 5% sodium hydroxide aqueous solution and talc powder to polish the surface, remove the hydrophilic layer, and restore the lipophilic characteristics of the ink roller. At the same time, the metal rolls (or hard rolls) are also treated accordingly. The hard roller can also be polished with fine water sand in the state of water drenching, and cannot be fixed at the same position, otherwise the rubber roller will be damaged. The fundamental solution is to control the pH value of the water tank, improve the balance of ink and water, and reduce the degree of emulsification of the ink.