Page 108 - Training 2019

Always use a blade oscillation that is as long as (e.g. Never use a short and rapid oscillation---it can cause
10-20 mm), slow and smooth as possible. uneven doctor blade wear at heavy image areas (solid
white panels) and at the edge of cylinders.
Always use printing cylinders with smoothly Never use printing cylinders with sharp and
rounded (polished) ends, conic end of 1 degree at unpolished ends---it causes quick formation of end
15-20 mm in from the cylinder end. wear and blade debris from ends falling into the ink.
Always use chrome cylinders with optimum surface Never use chrome cylinders with too low roughness
roughness (Rz between 0,4 and 0,6). (e.g. if cylinders have been used a long time) which
causes too low friction and can cause local heat
problems, damaging the ink’s function.
Never use too high cylinder roughness which can wear
out the doctor blade too quickly and cause scum or
hazy print problems.

Always use chrome cylinders with cross-hatch Never use chrome cylinders with straight polishing---it
polishing---it allows the ink to flow diagonally along causes lines in the print due to trapping of pigments
the cylinder. and particles.

Always use chrome cylinders with surface hardness Never use chrome cylinders with too low hardness---it
approx. 900 – 1100 HV (Vickers) causes higher friction and printing problems.
Never use too high hardness---it causes faster blade
wear and poorer wiping due to too low friction and
lubrication.

Always use a magnet in ink filters to trap worn-off Never print without filters and magnets.
steel dust from the doctor blades.
Always keep the ink tanks and trays covered---it Always prevent contamination of ink and prevent
prevents contamination and prevents evaporation of evaporation of inks.
the solvent.
Always use a lamella tip for the cleanest wiping and Never use a blade tip that is too thick and stiff when
lowest blade pressure. clean wiping is required, especially in half tone
printing.

Always use ink splash guards in good condition at Always use ink splash guards---to avoid unwanted
cylinder ends. splashing.

SWEDEV DO’S & DON’TS TRAINING MANUAL 4
Updated - 24 June 2019