Printing speed is often limited by the formation of small droplets, so called ‘misting’. The release of the ink follows an elongational pattern.
The HAAKE CaBER extensional rheometer can detect materials that are likely to mist or spatter.
Application Example: Offset Printing
Offset inks which performed well could not be differentiated by rotation or oscillation measurements from samples showing misting during the printing process.
The break-up times showed a significant difference – the shorter times lead to less misting.
Also the extensional viscosities of the two inks were significantly different with the better ink having the lower extensional viscosity.
Testing the extension properties before product application will identify products that are more likely to mist and spatter and allow you to adjust the formula and eliminate the problem. This would improve process and product performance and provide a new QA/QC procedural step prior to final production.