Doctor blades for chamber systems in flexo printing units
To accomplish optimal printing results, it is crucial to adjust the chamber doctor blade system correctly. While the doctoring blade actively supports the doctoring of the ink, the retaining blade has a sealing function. The seemingly plain steel and plastic blades thus play an important role in achieving high quality printing results.
Finding the right doctor blade for a specific printing application
The printing application environment is important for the doctor blade choice, similar to the end seal choice.
Important parameters for the choice of the doctor blade material, dimensions and profile are:
- Type of ink, i.e. solvent based, water based or UV inks or even abrasive metallic effect inks.
- Chamber geometry, including the type of blade holder, the angle position of the doctor blade, the contact pressure and the printing width.
- Structure of the printing job, i.e. many short runs with frequent ink changes and adjustments or long printing jobs that require long doctor blade lifespans.
- Individual demands, e.g. especially short start-up times, avoidance of burr formation or ink spitting, job safety or cost-performance ratio.
steelBLADE C
The steelBLADE C doctor blades are made of high quality carbon steel. This steel quality is the most sold doctor blade material in the world in the flexo printing industry.
This steel quality is suitable for solvent based applications and UV printing operations. We only recommend using the steelBLADE C doctor blades in combination with water based inks if the printing machine runs in three shifts and there is thus no danger of corrosion.
steelBLADE S
Our steelBLADE S doctor blades consist of an extra fine micro alloy of chrome and nickel. This stainless steel is corrosion-free and thus suitable for water based inks.
The steelBLADE S doctor blades can however be used for all types of inks, due to their wear properties and long lifespan.
steelBLADE T
The steelBLADE T doctor blades are our high-tech solution for strongly abrasive applications such as opaque white or irodine inks.
This special steel with a high hardness has excellent wear characteristics and enables high quality printing results even under extraordinarily high abrasive printing conditions.
When used under the same conditions, the lifespan of steelBLADE T doctor blades is three times as high as steelBLADE S doctor blades.
polyBLADE
We manufacture our polyBLADE blades from a wear resistant plastic.
Plastic blades can be used in chamber systems as a retaining blade and thus represent an effective and budget-priced alternative to steel blades. Due to its material elasticity, the flexible blade keeps permanent contact with the anilox roller and makes the chamber leakproof.
For some applications, such as corrugated and tissue printing, the polyBLADE blades can also be used as an active blade, i.e. a doctoring blade. Compared to the razor sharp edges of steel blades, the plastic blades reduce the danger of injuries. This is especially relevant for applications with long printing widths and consequently long doctor blades.
Fine tuning of the doctor blade
Besides the choice of material, the doctor blade profile, i.e. the cut of the doctor blade edge which is in contact with the anilox roller, is crucial for the performance of the doctor blade in the chamber.
Different types of profiles can be machined depending on the material structure of the steel and plastics blades.
Lamella
Finely grinded thinner section at the working edge of the blade ensures optimal contact of the blade tip with the anilox roller.
Eliminates start-up time.
Most common blade profile in the flexo printing industry.
Bevel
Wedge-shaped section at the working side of the blade that can be realized in different angles. For steel and plastic doctor blades.
Wedge-shape improves the stability at the contact zone and reduces the risk for edge breaks when under high pressure.
One-step lamella
Two-stage lamella for steel doctor blades with high thickness. Reduces vibrations and still has a precise contact zone.
Rectifies ink spitting problems.
Round tip
Polished round edge for steel blades provides for quick and even doctoring.
Good cost-performance ratio, especially for high doctor blade consumption.
Straight edge
Even profile for plastic retaining blades. Sealing function does not require a specific cutting, so it has an excellent cost-performance ratio.
Do you already know our bladeCUT service?
Instead of buying the doctor blades in rolls, you can receive them already precut in any required length.
That way you can insert them directly into the chamber.
This saves you time and reduces material loss.