Ghosting, a faint image from another part of the design that appears where it shouldn't, has always haunted the flexo industry. Ghosting is most obvious in areas where large solids are used and always on printed side of substrate in the image area.
Example of ghosting
What causes ghosting?
Fortunately, the cause is far from supernatural. While much has been written on the subject, most agree on these six issues as the most likely causes of ghosting.
- Ink starvation
- Ink fluidity is not appropriate
- Chambered doctor blade not adapted
- Mechanical issue
- Anilox roll is not properly cleaned
- Premature drying of ink on the anilox roll
What can I do?
Leave the Proton Pack at home! The next time you have an issue with ghosting, try working through each of these possible solutions.
- Increase ink level and/or pressure into the chambered doctor blade.
- Use higher anilox roller volume
- Add solvent (retarder) to increase ink fluidity, to flood the cells, and avoid ink drying into cells
- Use a specific design of the chambered doctor blade to force ink to flood the cells
- Select anilox roller where the circumference is a whole number multiple of the repeat length of the design times the number of plates round the cylinder or change the diameter of the plate cylinder
- Increase the speed of the machine
