Printing consumables attuned to the needs of offset packaging and commercial printing
Offset printing presses become more and more technically advanced, including digitally supported workflows, increased production speeds and inline-finishing technologies, which allow printers to respond to customer requirements and stay ahead of the competition.
Inline coating, be it full-area protective coating, spot coating, or a scented coating, with a matte, glossy or structured finish, is widely used to give printed products that certain extra look and/or function.
The inline coating units in offset presses operate on the flexographic principle with a closed chamber doctor blade system that requires well-matched end seals and doctor blades for optimum coating result.
Typically, water-based or UV coatings are used. Depending on the work load of the coating unit and the job structure, the service life of end seals and doctor blades sometimes extends over weeks, so they must offer good durability and wear-resistance.
Reliable quality and performance over and over again
To exploit the full potential of the printing press, it is important that offset printers can rely on the performance of the consumables in use.
AGSflexo's specialty are highly functional end seals and doctor blades of consistently impeccable quality. We produce end seals from wear-resistant rubber and impregnated felt types that are compatible for use with all common offset press models and chamber doctor blade setups. AGSflexo seals and blades qualify as alternative to the machine/chamber manufacturer's parts. Our doctor blades from steel and plastic are made for precise and uniform doctoring for high-quality coating results. By trusting in our end seals and doctor blades you can:
Best practice end seals for offset inline coating
For easy handling and all coating types
coatSEAL Universal
Our coatSEAL Universal seals are made of special rubber compositions. They have a high chemical resistance and excellent shape stability to ensure a tight fit and proper sealing result. Thanks to their pronounced wear-resistance, they have a long service life.
For UV coatings, our end seals are black, for water-based coatings our end seals are red, so they are easy to distinguish.
coatSEAL Universal rubber end seal solutions are compatible for use in all Heidelberg and manroland presses as well as most Komori, KBA and Ryobi presses (and all other press brands, where a Tresu chamber system is integrated in the inline coating unit) as replacement for the OEM parts.
For efficient sealing of water-borne varnish
coatSEAL Longlife
coatSEAL Longlife end seals are made of different thermo-impregnated felt types. They are a great choice when printers experience leaking issues with water based varnishes. The grease-based impregnation improves the sealing function, because it has a water-repelling effect and basically "pushes away" the varnish from the sealing area.
The lubricant used for the impregnation is food and cosmetic safe and is therefore often used for food and cosmetic packaging applications. We recommend to re-lubricate the seals on a regular basis in order to prolong the lifespan.
coatSEAL Longlife felt end seals are compatible for use in numerous offset press models, e.g. from Heidelberg, Koenig & Bauer, Komori, manroland and Ryobi across all formats as replacement for the OEM parts. Most presses with Harris & Bruno (H&B) chambers in the coating unit work by default with felt end seals.
Use lubrication grease for installation
The use of end seal lubrication grease with both coatSEAL Universal rubber seals and coatSEAL Longlife impregnated felt seals in the inline offset coating unit has several beneficial effects in inline coating units:
- It facilitates the installation of the end seal in the chamber doctor blade system
- It enhances the sealing function
- It extends the end seal's service life
- It can reduce the amount of cleaning required in the end seal area of the chamber
Best practice doctor blades for offset coating
Corrosion-free blade for all coating types
steelBLADE S
Our steelBLADE S doctor blades made out of high-quality stainless steel are all-rounders in an offset coating unit. Thanks to their resistance to corrosion, they can be used for water-based coatings as well as other types of coatings.
With a finely ground lamella steelBLADE S blades ensure optimal contact with the anilox roller for consistently high doctoring results throughout the blade's lifespan. Even if the coating unit is not in continuous use or if cleaning work is carried out in between jobs, this stainless steel doctor blade can continue to be used until the lamella is worn, as there is no risk of corrosion.
For UV coatings
steelBLADE C
Our steelBLADE C carbon steel blades offer great value for money for use with UV coatings. The lamella at the blade tips precisely transfers the coating into the anilox roller cells and wears out evenly.
The use of carbon steel blades with other than UV coatings types can only be recommended in certain print settings, such as when the coating unit is operated without interruption until the blade is mechanically worn out. Otherwise, corrosion on the blade could affect the coating outcome.
steelBLADE C doctor blades are also used in the ink chambers of the Heidelberg SM Anicolor and KBA Genius 52UV machines, which use oil based or UV inks.
For abrasive coating types
steelBLADE T
Our steelBLADE T doctor blades are manufactured from premium tooling steel and have been developed especially for finishing applications with highly abrasive coatings such as pearl or metallic effect.
Thanks to the hardened special steel alloy combined, the steelBLADE T doctor blades ensure an optimal and even doctoring with extended service life. When used under the same conditions, the steelBLADE T lasts about three times longer in comparison to the steelBLADE S.
For leak-proof sealing
polyBLADE S
Plastic blades can be used in offset coating units as a retaining (also known as containment) blade. Due to its high material elasticity, this flexible blade keeps permanent contact with the anilox roller and ensures a recirculation of the coating from not emptied cells into the chamber. This way, coating drops can almost be completely eliminated.
Since the function of the retaining blade does not require a specific blade profile and plastic is a lower-priced raw material compared to steel, our polyBLADE S doctor blades are a cost-efficient option for sealing the chamber.
What does it take to get high-quality, clean doctoring and coating results?
For optimum and clean coating results, both the active doctoring blade, which transfers the varnish onto the anilox roller, and the retaining blade, which seals the chamber along the anilox roller, need to function properly.
The active doctor blade is in most cases by default a steel doctor blade. Inline coating units of Heidelberg, Komori and manroland presses usually have Tresu chamber doctor blades installed, which work with doctor blades sized 35 x 0.20 mm (1.38 x 0.08 in). Some Komori presses and most KBA and Ryobi presses are equipped with H&B chamber systems, which work with blade dimensions 28 x 0.20 (1.1 x 0.08 in) mm or 25 x 0.20 mm (1 x 0.08 in). A lamella blade profile is standard for short start-up times and precise clean wipes.
The challenge: Overcoming leakage at the sealing blade
Many coating units use the same blade type for the doctoring and retaining blade. Depending on the geometrical chamber system setup and the position of the sealing blade in the chamber, printers might experience leaking issues related to back-doctoring at the sealing blade, especially with steep blade angles.
A standard steel blade has a high stiffness when positioned in a steep angle. Thus, if used as a retaining blade, it partially doctors varnish from the anilox roller instead of letting it flow back into the chamber. As a result, leakage might appear.
When the sealing blade is positioned on the bottom, leakage shows in the form of coating drops underneath the chamber. When the sealing blade is at the top, varnish may accumulate on the blade, which then flows towards the outer chamber ends and runs down or splashes at the anilox face.
In both cases, leakage affects the printing quality and costs time and money for cleaning and paper waste.
The good news is: Changing your sealing blade can resolve the problem!
Option 1:
Go for polyBLADE plastic blades
Due to its high material elasticity, the flexible plastic blade keeps permanent contact with the anilox roller and ensures a recirculation of the coating from not emptied cells into the chamber. This way, leakage can almost be completely eliminated.
Since the function of the retaining blade does not require a specific blade profile and since plastic is a lower priced raw material compared to steel, our polyBLADE S doctor blades are an effective alternative for coating units with an excellent cost-performance ratio.
Option 2:
Choose a modified steelBLADE for retaining
Alternatively, use a special version of our steelBLADE doctor blades. This retaining blade solution is also based on the flexibility of the material, which is created by reducing the steel thickness, e.g. 0.10 or 0.15 mm instead of 0.20 mm. On top of that, the retaining blade is oversized in width (e.g. 45 mm instead of 35 mm) so that the blade surface seals the chamber instead of the blade edge.
This leads to the blade opening slightly and giving excess coating the possibility to circulate back into the chamber.
More consumables to get the best out of your offset printing press
Besides end seals and doctor blades, we also manufacture wash up blades for the oscillating rollers in the offset printing decks as well as filters for dampening water circulators and ink mist extractors.
Additionally, we can provide related consumables, e.g. sheet separators, bearer ring felts, o-rings, coating tubes, etc., so that our customers can benefit from an all-round service.
In our webshop, you can find a large variety of consumables 24/7.
