CUED Publications database

DoD inkjet printing of weakly elastic polymer solutions

Hoath, SD and Vadillo, DC and Harlen, OG and Mcllroy, C and Morrison, NF and Hsiao, WK and Tuladhar, TR and Jung, S and Martin, GD and Hutchings, IM (2014) DoD inkjet printing of weakly elastic polymer solutions. In: UNSPECIFIED pp. 152-156..

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Abstract

© 2014 Society for Imaging Science and Technology. Fluid assessment devices, such as high frequency rheometers and torsion resonators, filament stretching and thinning systems, and oscillating DoD drops, requiring small volumes and avoiding the need for jetting, are particularly useful in the design of functional fluids for inkjet printing applications. With the increasing use of complex (rather than Newtonian) fluids for manufacturing, single frequency fluid characterisation cannot reliably predict good jetting behaviour, owing to the range of shearing and extensional flow rates involved. However, the scope of inkjet fluid assessments (beyond achievement of a nominal viscosity within the print head design specification) is usually focused on the final application rather than the jetting processes. The experimental demonstration of the clear insufficiency of such approaches shows that fluid jetting can readily discriminate between fluids assessed as having similar LVE characterisation (within a factor of 2) for typical commercial rheometry measurements at shearing rates reaching 10 < sup > 4 < /sup > rod s < sup > -1 < /sup > . Jetting behaviour of weakly elastic dilute linear polystyrene solutions, for molecular weights of 110-488 kDa, recorded using high speed video was compared with recent results from numerical modelling and capillary thinning studies of the same solutions. The jetting images show behaviour ranging from near-Newtonian to "beads-on-a-string". The inkjet printing behaviour does not correlate simply with the measured extensional relaxation times or Zimm times, but may be consistent with non-linear extensibility L and the production of fully extended polymer molecules in the thinning jet ligament. Fluid test methods allowing a more complete characterisation of NLVE parameters are needed to assess inkjet printing feasibility prior to directly jetting complex fluids. At the present time, directly jetting such fluids may prove to be the only alternative.

Item Type: Conference or Workshop Item (UNSPECIFIED)
Subjects: UNSPECIFIED
Divisions: Div E > Production Processes
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 19:09
Last Modified: 17 Aug 2017 01:25
DOI: