Doctor Blades & Consumables for the Printing Industry
Kai Theede, Managing Director Chalcographie Thiemecke GmbH
The FlexoTip doctor blade was specially developed for flexo printing and offers two major advantages when used in chamber doctor blade systems. On the one hand the 30 ° setting towards the anilox roller and on the other hand the FlexoTip-bevel angle. This one is rounded by 30° on both sides , which makes installation much easier. The thickness of the Flexotip doctor blade depends on the linearity of the anilox roller. Since no lamella grinding is required in conventional flexo printing, Flexotip doctor blades can be used with a thickness of 0,15 mm or 0,2 mm for many applications.
The fast doctoring is a great advantage compared to cut and deburred doctor blades. Another advantage is the longer service life compared to lamella doctor blades.
The Duroblade is the marathon runner among the doctor blades. Specially developed for the use on ceramic-coated anilox rollers, the Duroblade achieves a service life unmatched by any other doctor blade. It was designed to achieve a longer production time with extremely abrasive inks but is also distinguished as a continuous runner for process colors. The coatings differ between the classic Duroblade, which is used in low- to medium-resolution lines (L/cm) and the new type Duroblade HL+ for HD-Ready Flexoprinting, from medium- to high-resolution anilox rollers. The Duroblades thus cover the entire spectrum in flexo printing and coating.
Combi doctor blades are specially designed for gravure printing.
One of the biggest issues for many gravure printers is the premature wear of lamella doctor blades due to damage in the areas around the cylinder edges.
TKM has developed the combi doctor blade as a suitable solution.
A grinding pattern is created by a periodically lifting of the grinding wheels in a defined area. The grinding pattern allows the lamella to run out into the full material thickness.
Therefore, combination doctor blades are only available in individually lengthened pieces and not in rolls. The advantage is that the doctor blades can also be used on cylinders with a poor edge quality until the lamella is completely worn out. Therefore, there is no need for premature blade changes.
Until the 1970s, doctor blades were ground by printers themselves. This led to tone value fluctuations due to the grinding inaccuracy. For that reason, the lamella doctor blade was developed, which is characterized by a uniformly ground lamella and thus has a constant contact zone. This contact zone is constant within a tolerance range of ±5 µm. Due to the thin lamella, unevenness on the cylinder can also be evened out better than with the conventional wedge doctor blades.Until today the lamella doctor blade has established itself as industry standard in gravure printing.
The stable doctor blade was developed by TKM as a complementary product to the lamella doctor blade. The stable doctor blade has an increased contact zone compared to the lamella doctor blade, but it is extremely small due to the very flat angle with less than 0,01mm. In addition, the stable doctor blade retains the necessary flexibility to compensate for cylinder inaccuracies. Today, TKM sells almost half of its doctor blades as stable doctor blades.