Page 38 - Training 2019

After installing new end seals, a press operator should evaluate the
chamber and confirm that there is a snug end seal fit with no gaps or
distortion. The doctor blade should have some upward pressure to form an
adequate seal, but not so much that it requires extra loading pressure
to make contact with the anilox roller in the middle of the blade.

END SEAL MATERIALS FOR CHAMBER COATING SYSTEMS:

There are various end seal materials which range in abrasion resistance,
durability and solvent resistance:

Foam seals:
Foam seals do not perform as well as other materials and may not be a
good choice for long runs, higher press speeds and certain coating
chemistries. There can also be a lot of variation in the density of the
material which can range from super firm to more malleable. However,
these are the cheapest material options and can be punched, water or laser
cut for more accuracy

Plastic seals:
EPDM, Desmophan, Silicone and Neoprene seals offer longer life compared
to foam seals. They are compatible with aqueous and UV coatings so they
don’t have to be changed out between jobs. However, these seals do not
seat well due to the coefficient of friction between the material and the
anilox roller surface.

Pre-soaked felt:
Pre-soaked felt end seals are a superior solution for resolving coating
leaks. These end seals are oversized for a snug fit and pre-soaked in a type
of petroleum jelly to reduce friction and prevent coating build-up. Felt end
seals are compatible with all ink and coating types, provide a tighter seal
and typically last longer than rubber and foam seals.

CHAMBER BLADE END SEALS TRAINING MANUAL 4
Updated - 24 June 2019