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Scorelines, cellular bursts, reduction in print quality and many other disruptive factors are often caused by unsatisfactory handling and unskilled maintenance of anilox rollers. His experience, based on a great many training courses and practical studies show that simple processes and consistent application of standards help
to correctly maintain and operate anilox rollers on a long-term basis in order to keep the print quality high and the maintenance costs low. He gives insights into his daily work and experiences of how to work correctly with the high performance products, anilox rollers and anilox sleeves.
Anilox rollers and sleeves are an important component in flexographic printing. In many different areas of application, they serve to transfer ink, glue, coating materials and other media.
Anilox rollers and sleeves must meet stringent requirements in the printing process and achieve perfect results over an extended period. High-quality coatings and engravings that ensure precise colour transfer form the basis for this. In this respect, Michael Reuter explains that various aspects must be fulfilled in order to ensure that the high-quality rollers and sleeves achieve as long a service life as possible. Correct handling and professional care of these high-performance components are very important and have a positive effect on the life cycle of the roller.
To avoid mechanical damage, anilox rollers need to be well protected for transportation and storage. As standard, INOMETA uses protective covers and cushioned casings to protect the sensitive engravings and surfaces. Anilox rollers must be transported in stable boxes or special storage systems. It must be ensured that sleeves are transported on mandrels and anilox rollers must be stored on the roller journals. Damaged anilox rollers often have chipped radii and a cracked layer structure, which in turn can lead to surface damage. This is generally caused by improper handling, which is easy to avoid.
Reductions in the intervals between individual print jobs means increasing time pressure. As a result, the necessary care and cleaning processes for rollers and sleeves used to transfer colour are also reduced.
Quite often, dirty anilox rollers/sleeves are only superficially cleaned, or even in the worst case scenario not cleaned at all due to a lack of time or capacity. The result is dirty anilox rollers with dried-on ink in the bottom of the cells which makes them difficult to clean afterwards and involves extra effort. With the right level of sensitivity, this cost-intensive effort can be avoided by replacing the component directly on the machine. Manual cleaning with a sponge or brush is recommended – directly after use in the printing unit to keep the transfer fluids moist. The prevention of dried ink residues reduces the risk of damage to the sensitive anilox cells.
In addition to manual cleaning, used and therefore dirty anilox rollers and sleeves should be cleaned using a machine. Michael Reuter of flexographic printing system supplier INOMETA emphasises that manual cleaning may remove large ink particles, but cannot replace deep cleaning. The dried ink residues in the engraving should be removed right down to the bottom of the cell INOMETA also uses ultrasound cleaning – a service offering that many print shops take them up on. Successfully, explains Michael Reuter. This can be seen on the one hand in the service life of the anilox rollers and sleeves, but also in the print quality that is achieved with these components even after countless uses. Cleaning and attentive care pays off and leads to cost reductions in the long term.
In addition to the right cleaning process, choosing the appropriate cleaning agent plays a significant role in the interaction during correct handling of anilox rollers. The usual cleaning procedures include chemical and mechanical/abrasive procedures (baking powder/sodium hydrogen carbonate or plastic pellets) or processes using ultrasound or laser beams.
Some of the general factors in the assessment of cleaning systems are the costs for devices, consumables, environmental protection regulations, the ability to carry out cleaning processes both inside and outside the printing machine, the specifications of the anilox rollers (e.g. lines, roller material) and the time required for cleaning.
“Our fundamental tip for clients is to use systems that are not only designed for the respective inks and coating products and printing processes but also the cleaning plans and budget” adds application technologist and product manager Michael Reuter.
The most important factors are efficiency and duration when implementing the cleaning processes. In addition to this, the detrimental effects on the anilox rollers or other machine components must be taken into account. When using strong chemicals (with low or high pH value), there is a danger of damage or corrosion to the components. “Our procedure is fundamentally process-oriented so that we can give our customers an explicit recommendation for the selection of the right cleaning product, so that it does not damage the roller core, the coating or engraving , but still cleans effectively.
Good service saves money and extends the life cycle of anilox rollers and sleeves. If the components no longer work perfectly, this does not necessarily mean that the rollers have to be completely replaced. Often, the wear only affects the upper layer structure, whilst the roller body is still of good quality. In this case, reconditioning technologies offered by INOMETA can be used for anilox rollers and sleeves. Significant procurement cost savings can be made. “Based on a condition check of the base core, our specialists assess the degree of damage and decide whether a cost-intensive new construction is required” adds Michael Reuter in conclusion.
For further information, please visit the Website for INOflex Printing Products at printing.inometa.de