eprintid: 10185378 rev_number: 15 eprint_status: archive userid: 699 dir: disk0/10/18/53/78 datestamp: 2024-01-12 14:44:44 lastmod: 2024-06-04 14:33:26 status_changed: 2024-01-12 14:44:44 type: article metadata_visibility: show sword_depositor: 699 creators_name: Shi, Jing creators_name: Cagney, Neil creators_name: Tatum, John creators_name: Condie, Angus creators_name: Castrejón-Pita, J Rafael title: Jetting and droplet formation of particle-loaded fluids ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F45 note: Copyright © 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). abstract: Inkjet printing is an attractive method for patterning and fabricating objects across many areas of industry. There is a growing interest in the printing of inks with high particle-loading, such as inks containing glass frit, ceramic and functional inks. However, the use of these inks is often limited due to uncertainty regarding the impact of their rheology on the printing process. Understanding of the role of complex rheology in the jetting of loaded inks is therefore needed to facilitate the wider application of inkjet printing. Here, we characterize the complex rheology and the jetting of model dispersion inks (containing 10, 15, and 23 vol. % TiO2 nanoparticles) and compared them with those without particles. The jetting of the model fluids was conducted with a commercial inkjet printhead (nozzle diameter 34 lm) and visualized with stroboscopic and ultra-high-speed imaging. For low particle concentrations, droplet formation is generally similar to those of unloaded inks, provided their Ohnesorge number and Weber number are matched, although the filament of the loaded model fluid tends to have earlier break-off, having a shorter length. The jetting reliability decreased with increase in particle-loading until reliable jetting can no longer be achieved, due to local particle–particle interactions in the ink channel and in the filament during the fast extensional thinning process. A jetting map is presented which illustrates the influence of particle-loading on the droplet formation, and indicates that the acceptable range of Ohnesorge number for jetting is reduced as the particle-loading is increased. date: 2024-01 date_type: published publisher: American Institute of Physics official_url: https://doi.org/10.1063/5.0180014 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2139239 doi: 10.1063/5.0180014 lyricists_name: Castrejon Pita, Jose lyricists_id: RCAST38 actors_name: Castrejon Pita, Jose actors_id: RCAST38 actors_role: owner funding_acknowledgements: 10003708 [InnovateUK - KTP]; EP/V04382X/1. [Engineering and Physical Sciences Research Council]; UCL IAA 2022-25 [Engineering and Physical Sciences Research Council] full_text_status: public publication: Physics of Fluids volume: 36 number: 1 article_number: 017119 issn: 1070-6631 citation: Shi, Jing; Cagney, Neil; Tatum, John; Condie, Angus; Castrejón-Pita, J Rafael; (2024) Jetting and droplet formation of particle-loaded fluids. Physics of Fluids , 36 (1) , Article 017119. 10.1063/5.0180014 <https://doi.org/10.1063/5.0180014>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10185378/1/Castrejon%20Pita_017119_1_5.0180014.pdf