The application of anilox roller in the heart of t

The heart of flexo printing machine: the application of corrugated rollers (Part 2)

daily maintenance of ceramic corrugated rollers

* reasonable selection and allocation of corrugated rollers: ceramic corrugated rollers with a certain number of lines and BCM value should be selected according to the printing plate pattern, printing ink volume, printing paper and post-processing technical requirements. Selection of doctor blade: the special doctor blade for flexo printing and appropriate pressure should be selected. The standard is to remove all the excess ink on the surface of the ceramic roller. Too much pressure will damage the service life of the roller

* when changing the printing plate, or before going off duty, the wrinkle roll should be cleaned in time, so that it can be cleaned at one time without leaving ink residue. The best cleaning effect is to use hot water and a special stainless steel brush for the wrinkle roll

* when using UV ink, although it is not necessary to clean the wrinkle roll and ink tank when the operation is stopped, it is recommended to take measures to avoid light. If the embossing roller is exposed to sunlight or light for a long time, the UV ink will still dry and solidify in the hole because it feels that there is oxidant in this kind of water. UV ink solidifies in the groove roller hole, and it is troublesome to clean it again. In the replacement operation, UV ink cleaning is mainly industrial alcohol cleaning

* replace the corrugated roller and clean it in time

* place a magnetic filter in the ink tank to avoid metal impurities scratching the wrinkle roll

* select high-quality scraper and blade type. It is recommended to use plastic scraper to better protect the wrinkle roll

* use a hole microscope to detect holes. If wear and blockage are found, measures should be taken in time

* the machining allowance of the edge of the ceramic roller can be appropriately reduced and protected according to the agreement of both parties: generally, the edge of the roller is made into 90. At right angles, the ceramics on the edge are easily bruised when removing the corrugated roller and loading and unloading the bearings and gears. When the pH value of the ink exceeds the standard, the base of the corrugated roller can be corroded through the bruise, causing the ceramic layer to fall off and the corrugated roller to be scrapped in advance. In addition, it is easy to cause early wear and scrapping of the doctor blade. Suggested solutions: (1) buy ceramic roller with edge chamfer. According to empirical data, 0.22mm chamfer is the most ideal in machining, so adding a fine machining of edge chamfer to the processing technology of ceramic roller can make the roller not easy to wear in use. (2) When replacing the corrugated roller, protect the surface of the corrugated roller. When storing, use a leather cover. A well-made leather cover can play a good shock absorption role and keep the surface of the corrugated roller clean at the same time

cleaning of ceramic corrugated rollers

the cleaning of corrugated rollers is divided into daily cleaning and periodic cleaning. Daily cleaning is to clean the wrinkle roll in time after shutdown, which can effectively prevent the ink from drying in the hole. For corrugated rollers with serious hole blockage, the effect of periodic cleaning will be more obvious

at present, the cleaning methods of ceramic roller include organic solvent cleaning, chemical solution immersion cleaning, mechanical powder spraying cleaning, plastic bead spray cleaning, ultrasonic cleaning and special cleaning agent cleaning

* organic solvent cleaning: most solvents do not have obvious cleaning effect on the residue of ink and UV ink solidified in the hole. In addition, the solvent itself has rarely been used for its impact on the environment and human body

* chemical solution immersion cleaning: soak all or part of the wrinkle roll in a highly corrosive cleaning tank with high pH value, let the solvent dissolve and soften the dry ink, and finally clean the solution and the corroded and softened ink with clean water. Although this method is effective, long-term use will penetrate the protective layer of the ceramic roller, corrode the steel body, and is not conducive to environmental protection

* mechanical powder spraying cleaning: mainly rely on low-pressure injection of modified baking soda to remove the ink residue, resin and coated cloth in the hole. This kind of equipment should be of fully enclosed structure, such as open operation. Although the water curtain is used as the protective layer, the splash of water and dust is still a headache. The consumption of special baking soda powder in the process of cleaning ceramic roller is large. As sodium bicarbonate and sodium bicarbonate are softening cleaning media, they are non-toxic, harmless and soluble, meeting the requirements of environmental protection. It is worth noting that in the cleaning process, DSM and even halogen-free flame retardant compounds that can provide CTI up to 600V, the injection pressure should not exceed 0.1MPa, otherwise the ceramic coating can fall off from the roll body

* plastic bead spray cleaning: using plastic beads as cleaning powder can make the cleaning of the corrugated roller usually adopt physical or chemical modification technology, and the speed is 30% higher than that of low-pressure mechanical powder spraying. At the same time, it can prolong the service life of the corrugated roller and improve the quality of prints. Using the improved method, the consumption of plastic beads is less, and there is no discharge of harmful substances and precipitation of chemicals in the cleaning process, which is conducive to environmental protection,

* ultrasonic cleaning: using an ultrasonic generator and a specially prepared cleaning solution, place the corrugated roller in the cleaning solution, and clean out the ink residue in the hole under the action of ultrasonic oscillation. Due to the need to add cleaning fluid into the cleaning tank, different types of ink need to be replaced with different types of cleaning fluid, and the cleaning fluid must be provided by the supplier, which is the most inconvenient choice. Ultrasonic oscillation plays a slow role in the whole cleaning process, and the cleaning time is long

* ceramic roller cleaner: This is a new cleaner developed for the curing layer of ink and UV ink in the hole. It is characterized by convenient use, remarkable cleaning effect, no need for any auxiliary settings, and can quickly remove the ink residue in the hole. The user only needs to apply this paste cleaning agent to the surface of the ceramic roller. After more than ten minutes, brush it with a stainless steel brush for the roller, and then rinse it with clean water. The whole ceramic roller is cleaned immediately

ringier Liu Qing

information source: packaging, printing and processing 2005, 10