Spray has traditionally been
the baen of our lives as print finishers
because too much of it on the sheet surface
can interfere very noticeably with both the
visual quality of the job and the adhesion
of the film to the sheet. Of recent times
our change to water based adhesives and the
increasing use of print sealers has reduced
the numbers of problems to more manageable
levels.
We still however see many jobs affected
by irregular clumps of spray particles
that we
term 'spray bombs'. These are caused by clogged
spray nozzles or by spray falling from gripper
bars or machine parts in the print delivery.
It is very difficult to clean a job once
it is contaminated by spray bombs, and the
usual
resolution is to run it and sort after cutting
into singles.
Recommendations
Please use the minimum amount
of the finest grade spray powder needed to
prevent set off.
Encapsulated
powders are free flowing, even in humid conditions,
and help to prevent clogging
of nozzles. |