SMEARING/TRACKING

A print defect where an unwanted image appears, often as a dark line in a light or solid print area. Tracking occurs when two print stations, which are often next to each other, interact.

 

Causes: 

- Excessive ink application;

- Dirty printing plates;

- Ink viscosity too high;

- Ink drying too slowly;

- Die cutting or folding operations:

  1. Worn or rough anvil blankets;
  2. Excessive cutting die pressure;
  3. Worn or slipping folding belts;
  4. Guides, rails or bars hitting print;
  5. Stacker belts hitting print.

 

Solutions:

- Clean and replace doctor blade;

- Clean plates;

- Reduce viscosity;

- Increase drying speed of ink by reducing viscosity, reducing ink film thickness with better metering. Decrease machine speed and increase dryer temperature;

- Optimise converting operations: Replace or trim/grind anvil blankets;

- Remove die rubber, replace knives, reduce die pressure, replace anvil blankets;

- Replace or adjust folding belts;

- Adjust or remove to minimise impact;

- Move or lift belts from print areas.