Excessive foam present in the printing unit, tray or ink pump unit.



- Ink too weak or too low in viscosity;

- Plate surface uneven;

- A coating left on the plate surface from plate making;

- Dirty or pitted impression cylinder;

- Uneven or unreceptive substrate;

- Ink not wetting out on substrate;

- Ink reticulation caused by excessive of antifoam;

- Foreign matter collecting on plate surface;

- Worn anilox roll.



- Add fresh ink or medium to correct viscosity for greater opacity level;

- Increase plate to substrate impression. Increase ink viscosity. Increase ink film thickness. Use softer plate durometer;

- Wash plate thoroughly with a compatable cleaning solution. Remake plate;

- Impression roller must be thoroughly cleaned of ink and other foreign materials;

- Use softer or compressible plates or cushion mounting tape. Check treatment levels on substrate;

- Ensure solvent balance is correct. Change ink system. Contact ink and substrate supplier;

- Replace with fresh ink;

- Thoroughly wash plate. Check ink filters are working. Check supplier re detack level of plate. Ensure plate surface is not wiped with aggressive solvents;

- Examine anilox roll for wear, plugging or for exces­sive land areas. Use a higher screen anilox roll.