Ink Set Off & Blocking
Ink is transferring from one page to the next or book to book when completed.
Printed signatures or sheets in bundle or load are sticking together.
| Cause | Cure |
|---|---|
| Oven temperature too low for web speed. | Increase oven temperature. |
| Excessive ink film thickness | Decrease ink settings, or consult ink manufacturer to increase strength. |
| Air flow in oven not sufficient to remove solvent vapors. | Increase air flow at air-knife scavenger at dryer exit. |
| Chill system not working properly. | Lower chill roll temperature to make sure ink resins are setting properly. |
| Paper stock is not porous enough, water content too high. | Switch paper stock for better porosity and moisture content. |
| Bundling pressure setting too great causing a resoftening of ink. | Adjust pressure to manufacturers specifications. |
| Ink taking on too much water. | Consult ink manufacturer for lower water pickups. |
| Incorrect pH and conductivity in fountain solution. | Check pH and conductivity of solution, rebatch if not at correct settings. Consult Fountain chemistry supplier. |
| Ink not drying at normal operating conditions | Consult Ink manufacturer. |
| Ink is only drying on surface. | Reduce press speed and adjust oven temperature to adequately dry ink. |
