Application of cooling water equipment in printing and precautions

The use of cooling water equipment in printing and precautions: in printing, the roller cooling system is easy to be ignored because there are few things that our printing operators need to do at ordinary times and only need to open it every day In fact, if it is not handled well, there will be many problems, which will affect the printing quality and even the printing time The water cooling system of ink roller adopts circulating cooling water to reduce the temperature of ink roller The water is input into the roller core of the inking roller through the cooling device to cool the rubber roller Then, the water flows back to the cooling device and circulates automatically to cool, so as to control the temperature of the ink and achieve good viscosity and rheological properties of the ink Several problems should be paid attention to in the use of the roll cooling system: first, the setting of the temperature In principle, the temperature of the cooling water is set according to the height of the room temperature, which is generally required to be about 3 ℃ lower than the room temperature From our practical experience, the temperature of cooling water can be set at four to five degrees below the room temperature, and it needs to be adjusted according to the air humidity If the humidity in the air is high, the set temperature of cooling water should be adjusted appropriately This is because the higher the humidity is, the easier it is to condense water drops on the roll It seems a little complicated, but in fact, it can be judged by a relatively simple method After the cooling system is turned on for a period of time, touch the copper head at the connection between the cooling water pipe and the roll If it feels supercooled, it means that the temperature is too low and the set temperature needs to be increased After the increase, it should be felt cool by hand during the printing process, even after the shutdown for a long period of time, when the cooling system is turned on, and there will be no condensation water drop at the copper head, so It means the temperature will not be too low However, it can't feel the heat of copper head when touching with hands If the temperature is too high, the cooling effect is not good, and it's easy to have troubles such as dirty plate Previously, we encountered a time when the printing monochrome is black, when the ink color is increased, the plate will be pasted badly, when the ink volume is reduced, it's not enough, and the plate is always dirty At that time, we checked the pressure of ink roller, roller, plate cleaning and rubber blanket changing, and thought about many things None of them can be solved It wasn't until the next day that it was discovered that the cooling water inlet of a single printing unit had been turned off These problems are caused by too high temperature of the tandem roller If the temperature is set too low, it is easy to produce too much condensation water in the ink path, which will damage the ink balance, or the folding machine and paper break and other problems mentioned above Even if there are no more serious problems, it will affect the printing process and reduce the quality of the printed matter Zui is obvious that there is a lot of condensation water in the roll, and the paper will expand along the axial direction after absorbing too much water, which will seriously affect the accuracy of overprinter In addition, the drying of our newspaper printing mainly depends on the infiltration of paper fiber The water content of the ink is too high due to the generation of condensation water in the ink, which makes the newspaper not easy to dry When the paper belt passes through the paper roller, the layout will be badly scratched, and more ink will be piled up on the paper roller, the triangle plate in front of the folding machine, the folding machine roller, the impeller and other places Secondly, when the printing machine is stopped in the middle of the process, especially when it needs to be stopped for a long time, the cooling water shall be turned off, the cooling water shall be temporarily stopped and the cold water shall be delivered to the printing machine Moreover, the water inlet and return pipes of the cooling water system are all directly connected to the tandem roller When the printing machine is running, the water pipes will also move back and forth along the axial direction along with the tandem roller Therefore, when installing the water inlet and return pipes, it should be noted that the water pipes cannot touch other parts such as the plate making motor when they move in tandem with the tandem roller, and if there is any connection between the water pipes After the printing machine runs for a long time, it should also pay attention to check whether the water pipes are worn due to mutual friction We have happened many times The water pipe is worn out Once it leaks, it must be stopped for treatment Therefore, we should do a good job of inspection at ordinary times, so as not to affect production In addition, in order to prevent the water leaked from the water pipe from entering the electric cabinet on the operation surface, a waterproof cover can be added on the inner side of the electric cabinet to cover the electric wire and prevent the water from entering the electric cabinet from the wire inlet.