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Jetting behavior of polymer solutions in drop-on-demand inkjet printing


Type

Article

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Authors

Hoath, SD 
Harlen, OG 
Hutchings, IM 

Abstract

The jetting of dilute polymer solutions in drop-on-demand printing is investigated. A quantitative model is presented which predicts three different regimes of behaviour depending upon the jet Weissenberg number Wi and extensibility of the polymer molecules. In regime I (Wi < ½) the polymer chains are relaxed and the fluid behaves in a Newtonian manner. In regime II (½ < Wi < L) where L is the extensibility of the polymer chain the fluid is viscoelastic, but the polymer do not reach their extensibility limit. In regime III (Wi > L) the chains remain fully extended in the thinning ligament. The maximum polymer concentration at which a jet of a certain speed can be formed scales with molecular weight to the power of (1-3ν), (1-6ν) and -2ν in the three regimes respectively, where ν is the solvent quality coefficient. Experimental data obtained with solutions of mono-disperse polystyrene in diethyl phthalate with molecular weights between 24 - 488 kDa, previous numerical simulations of this system, and previously published data for this and another linear polymer in a variety of “good” solvents, all show good agreement with the scaling predictions of the model.

Description

Keywords

jetting, polymer, modeling

Journal Title

Journal of Rheology

Conference Name

Journal ISSN

0148-6055
1520-8516

Volume Title

Publisher

Society of Rheology
Sponsorship
Engineering and Physical Sciences Research Council (EP/H018913/1)