Anilox roller ultrasonic cleaning

With the use of webbing in the flexo printing process, the drying of ink and paper powder in the mesh of the anilox roller is gradually blocked. Therefore, the ability of the mesh to transmit ink will be reduced. Therefore, the anilox roller should be regularly cleaned to maintain a stable quality of the ink. There are many processes for cleaning the anilox roll, and ultrasonic cleaning is one of them.

Principle of Ultrasonic Cleaning The electronic oscillations produced by the engine are converted into mechanical vibrations by the sound transducer and then transmitted to the cleaning liquid. This will generate cavitation bubbles in the cleaning fluid. At this time, the vapour bubbles form and inwardly burst, and are more likely to come in contact with any small particles. The irregularity of the surface of the object to be cleaned is also very similar to that of the particles. The cavitation bubbles completely hit the surface of the object and the dirt was cleaned. Ultrasonic cleaning processes are especially effective for cleaning thin, hard ink layers. For thick and soft ink deposits, longer cleaning times are required.

Anilox ultrasonic cleaning effect This process of cavitation bubbles penetrating into small holes is very useful for the cleaning of the mesh. Aggregates at the bottom of the mesh are easily removed, and the same is true for fine lines of anilox rolls. According to the analysis, the characteristics of the surface of the anilox roller and the fineness of the screen do not have a great influence on the result of the cleaning.

In order to ensure complete cleaning of the entire surface, it is important that the roller be rotated during ultrasonic processing. Because of the presence of interference, the distribution of sound intensity in different areas will be different. If the roller is not rotated, it will be cleaned very cleanly on some parts of the surface, while other areas can only produce trace removal effects.

Inks and detergents Cleaning agents are a very important factor in the ultrasonic cleaning process. The cleaning agent must be able to attack the ink, or at least the ink will expand, to help the ink completely removed under the effect of the ultrasonic. In general, the greater the adhesion, the more resistant to abrasion and cleaning the ink and polish, the more difficult it is to erode. This is why there is no universal cleaner. The usual experience is:

1. Water-based inks for paper and paperboard, usually using a mild, alkaline aqueous cleaner, have a good cleaning effect at about 50°C.

2. Most solvent-based inks and UV inks use strong alkali cleaners at temperatures around 60°C to 70°C, with good cleaning results.

3. For highly cross-linked residues (two-component inks, solvent-based inks with cross-linking agents, some water-based inks and varnish), corrosion may no longer be acceptable. With proper cleaning agents, only moderate erosion of these residues can occur, resulting in swelling. At this time, when ultrasonic treatment is performed, the time is longer, and it is necessary to use a strong alkaline detergent, if necessary, to mix with a low-flavor organic solvent, or to perform sufficient manual cleaning.

These cleaners have a long potential period because the small solids on the rollers are generally small. Experience has shown that pure organic solvents are not recommended for cleaning in ultrasonic solvent environments.

Damage to Anilox Rollers Users are generally concerned about what kind of roller is suitable for ultrasonic cleaning. As a rule of thumb, only rollers that are ceramic coated directly on the copper layer are dangerous to handle. Because, this will make some hard ceramic peel off from the soft copper layer. Corrosion caused by the use of alkaline cleaners can even exacerbate this effect. In fact, the rotation of the roller during the ultrasonic treatment also has a great influence on its protection problem because it will ensure that all areas of the roller surface are exposed to the same degree of ultrasonic waves.