Even dyed-in-the-wool experts are not always aware that end seals on chambered doctor blade systems can have a negative impact on print quality in flexographic printing. But what are the reasons for this?
How and what measures can printers take on flexo presses to neutralise the end seals as a potential source of errors? What method can he or she use? What improvements can be made? The following article provides answers to these and other questions.
In order to seal the chambered doctor blades, a sealing material that is too soft without a support bar requires a higher pressure setting, which results in higher friction. A build-up of heat that develops in the system from this causes partially stronger materials to stretch. This increase in pressure on the anilox sleeve produces a higher pressure on the outer edges of the cylinder compared to the middle of the sleeve. The differing pressure disrupts the equal transfer of ink from the plate onto the material to be printed in an axial direction. Read the full article in our eDossier “End seals for chambered doctor blade systems in flexographic printing”.
Qualitative requirements in flexo printing
The trend towards high-quality printed film packaging continues, especially in the food industry. In our fast-moving times, finely dispersed packaging designs rich in detail increasingly often assume the status of the sole product presentation. However, this in turn results in the technical print quality of packaging also impacting in a significant scale on the economic success of a product.
In the individual market segments, the number of product varieties has increased in the last few years just as extensively as the number of taste variants per product group. In the event of an unchanged market size, this necessarily means a reduction in the individual print runs. The unbroken trend towards “fresh” goods is a further indication of the reduction of the respective lot sizes while the number of repeat prints is rising at the same time.
In the process, it is unavoidable that the same packaging from different production runs are placed next to each other on shop shelves, perhaps with only slightly differing use-by dates. Standardised processes with uniform print quality for packaging productions is critical. In order to get more information, visit our shop to download the whole article for EUR 3,99.
Competition for flexo printing
With these relatively high requirement profiles, is flexographic printing – in comparison to gravure and digital printing – still able to compete? There is no doubt that flexographic printing is a serious rival to both processes. But only if it uses the optimally coordinated technical parameters as production standards for high-quality printing.
Undoubtedly, digital printing also still has numerous process-influencing obstacles to overcome. These include printing on difficult, extremely thin substrates and the fulfilment of certain requirements of inking and coating systems (e.g. surface-homogeneous white covering with high opacity, printing with effect colours).
However, gravure printing is not free of handicaps either. One of the biggest economic hindrances is the production of very short print runs. A further weakness with small packaging sizes which have small product illustrations and coloured body texts is the influential, not always optimum register accuracy. Learn more about the “End seals for chambered doctor blade systems in flexographic printing” – you can easily download it for EUR 3,99 in our shop.