• PF-3DP temperature and idle time destabilize AgNP jetting. • AgNP inks show transient and irreversible clogging under PF-3DP conditions. • Carbon ink exhibits stable jetting under PF-3DP-like conditions. • AgNP clogging arises from solvent loss and nanoparticle accumulation. • Findings guide ink and process design for powder-based inkjet printing. Powder bed fusion 3D inkjet printing (PF-3DP), including Multi Jet Fusion (MJF), enables the integration of functional inks within powder-based substrates, allowing conductive features to be embedded directly into additively manufactured parts. In this process, carbon-based inks act as energy absorbers for powder fusion, while conductive silver nanoparticle (AgNP) inks can be co-jetted to impart localized electrical functionality. However, the elevated processing temperatures and intermittent jetting inherent to PF-3DP often lead to nozzle clogging when using AgNP inks. Here, we systematically investigate the coupled effects of printing temperature and nozzle idle (non-jetting) duration on the jetting behavior of AgNP ink, using carbon ink as a thermally robust reference. High-speed imaging, droplet volume analysis, and post-jetting nozzle characterization reveal that AgNP ink is highly sensitive to thermal exposure and prolonged idle periods, resulting in transient clogging, droplet misalignment, and increased deposition variability, whereas carbon ink maintains stable jetting. Scanning electron microscopy and nozzle surface analyses confirm AgNP agglomeration and residue accumulation at the nozzle orifice, directly linking jetting instability to solvent evaporation and nanoparticle accumulation. These findings define thermal and temporal stability limits for AgNP inks under PF-3DP conditions and inform ink and process design for powder-based inkjet manufacturing
Lim et al. (Sun,) studied this question.