When buying a printing press, the inking.
damping and distribution rollers with which it is fitted
will have been designed for use with that particular model and
make of machine. Although most modern rollers are made of
nitrile rubber. press manufacturers specify the hardness.
diameter and correct roller pressure for their machines.
Consequently. when replacing rollers, the new ones must adhere
to the correct specifications.
The hardness of rubber is represented by ascale of one to
100 on a Shore 'A' scale
Most inking rollers fall within 25 to 30 Shore and most
distribution rollers between 25 and 40.
Today's roller technology is very advanced and a modern
roller. manufactured to fine tolerances will provide a fine.
even surface which is hard wearing. However, there are
different grades of rubber and one compatible with the ink.
solvent and substrate must be used.
If changing to alcohol damping on the press. then the
rollers should be replaced with ones which are more
hydrophilic. If ultraviolet facilities are added, you may be
able to change just your wash-up, but check this with the
roller supplier. In fact, it is wise always to check with your
roller supplier before changing any inks or solvents.
Roller coverings are subjected to various
chemicals during their use, from inks and damping
solutions to washing up and cleaning agents. Be sure only to
use recommended chemicals and always wash off thoroughly
To scavenge a roller to remove dried ink. there are cleaning
pastes which can be put on the roller after it has been taken
out of the press. These pastes are effective but never use one
designed for off press use with rollers still on the machine.
Do not let the roller become contaminated with substances like
machine oil or silicon spray.