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17.04.2023 14:49 Age: 1 year

How to optimally use impregnated felt seals in chamber doctor blade systems

Especially when printing or coating with water-based and UV inks, felt seals can contribute to a more efficient printing process and higher equipment availability.

Impregnation serves as an ink-repellent protective shield

Chamber doctor blade seals made of impregnated felt are particularly popular when printing or coating with water-based and UV inks. The grease-containing impregnation acts as an additional ink-repellent protective shield to prevent ink and coating from leaking and depositing. This results in a better sealing effect. In addition, it also facilitates cleaning of the chamber doctor blade system, as the sealing area remains clean.


Safe and clean use in packaging printing thanks to foodsafe impregnation

For safe usage in packaging printing for food or pharmaceutical products, we at Agergaard Graphic Supplies use harmless, food-safe impregnating agent and technical felt made from the natural product sheep's wool for our coatSEAL Longlife felt seals. The impregnation is carried out in a special thermal process, which ensures that the seal is impregnated right to the core. In combination with the special rheological properties of the impregnating agent, the surface of the seal is constantly relubricated throughout its service life. The friction of the rotating anilox roller on the end seal generates frictional heat, which activates the impregnating agent in the seal and causes it to migrate to the surface of the sealing face to maintain the anti-frictional properties of the seal.


Numerous advantages when using impregnated felt end seals:

  • The seals work better and longer
  • More meters or sheets can be printed with one set of seals
  • Less seal changes are required
  • The productive time of the press can be increased
  • The sealing area of the chamber can be cleaned more easily and quickly
  • Leakage and the associated ink loss are avoided or significantly reduced
  • The press runs more cost-efficiently. Due to the improved sealing effect and service life of the chamber doctor blade end seals, there is less makeready-related press downtime during the print job


To make the most of the advantages of the felt seal, doctor blades that live up to the potential of the end seals should be chosen.


Tips for correct installation of felt end seals

During installation, a few points must be observed to ensure that the impregnated felt seal functions optimally:


  1. Careful handling without excessive pressure. Felt does not have any restoring forces. Make sure the end seal is not deformed during installation.
  2. The end seal should be placed in correct position in the chamber doctor blade system. When the gasket is fixed in the chamber, it is helpful to use your fingertips to gently shape the gasket again in corners of the chamber and on the contact surface with the anilox roller.
  3. Re-greasing the gasket surface with suitable gasket grease can further extend the life of the felt gasket. For example, if it is necessary to change the doctor blades before the print job is finished, it is worth re-greasing the seal to take advantage of the maximum service life of the seal.


For the correct handling and installation of felt seals, there is also a video tutorial on our YouTube channel.