The colour is lacking in colour strength and body.
Causes:
– Excessive reduction in ink viscosity;
– Excess extender varnish;
– Ink settling out;
– Ink film thickness too thin;
– Dirty/worn anilox rolls;
– Wrong fountain roll specification;
– Tight setting of fountain roll nip;
Solutions:
– Add fresh ink to restore viscosity;
– Add pigment concentrate (toner);
– Thoroughly mix ink in container before adding to ink tray;
– Increase ink thickness by raising ink viscosity, reducing metering of anilox roll or increasing the anilox roll volume;
– If plugged thoroughly clean anilox roll, if excessive land areas exposed, replace anilox roll;
– Select a lower durometer fountain roll;
– Decrease fountain nip roll pressure.
