It is best to clean rollers after print run. at colour
changes and between long runs to ensure longer roller life and
print quality. At least once four weeks, or if fast-drying inks
or dusty paper have been used. the rollers should be thoroughly
cleaned. inspected and regenerated with the appropriate
maintenance agents. Never use wire brushes, paper or other
abrasive matenals for cleaning and use aggressive wash-up
A roller will only perform effectively if it
has been correctly set. If it is too light it could lead
to ink variation or damping solution transfer If the pressure
is too severe. the resulting heat build-up could lead to the
breakdown of the roller covering plus premature wear. Check
with the supplier if in doubt.
To avoid uneven setting. which would result in overloading.
care should be taken to ensure that rollers are always set
parallel to each other. In other words. the nip is constant
over the whole of the length of contact. If the full forme
width is not being printed. the parts of the roller not
inked-up should be protected from running with oil or acid·free
grease. Check with the machine manual or contact the press
manufacturer the correct nip settings.
TRANSPORT AND STORAGE
When moving rollers, never let the covering
come into contact with anything and when storing.
support them only on the shaft. do not rest them on the
During storage. protect the covering from direct light and
and keep the relative humidity at around 65 per cent The
surrounding temperature should be kept to between 20 and 30 deg
Do not store rollers near electrical equipment which may give
There are awide variety of specialised
rollers used in print. Examples of the more popular ones
are hickey pickers (to reduce loose fibres affecting print
quality). EPDM grades for 100 per cent ultraviolet printing and
polyurethane rollers. used for blanket washes. Before using a
special roller. always consult the supplier to ensure
compatible washup and maintenance products are used.