Ink-Jet Printing of Polymer Solutions in the Semi-Dilute Regime
Abstract:The influence of polymer concentration on going from the dilute through the overlap into the concentrated regime during drop on demand inkjet printing is investigated for a range of cellulose ester (CE) polymers from visual examination of ligament stretching as a function of applied wave form. The physical behaviour of the fluids in drop formation is indicative of the dominance of viscoelastic effects within the timescale of the process, in preventing ligament breakup at the pinch point compared with a glycerol / water / iso-propanol blend Newtonian fluid of similar viscosity. When formulated at the overlap concentration all polymers showed qualitatively similar behaviour with respect to time and length of ligament at rupture irrespective of polymer molecular weight. Beyond the overlap concentration the ligament rupture times continue to increase with increasing elasticity of the solutions but the ligament rupture lengths decrease rapidly. In this regime coil overlap and entanglement effects become increasingly important, dramatically increasing the elastic nature of the ligament. It is proposed that in the case of weakly associating polymers such as cellulose esters, the effective relaxation time is further increased due to the possibility that on chain extension intramolecular H-bonds are broken and may reform in the extended form as intermolecular associations. These intermolecular associations act as physical crosslinks, thereby creating a transient gel structure. Because these associations are transient in nature, this gel structure is capable of having a finite large viscosity. Once the strain is removed the gel will decay as the chains return to the more thermodynamically stable coil state.
Document Type: Research Article
Publication date: January 1, 2007
For more than 25 years, NIP has been the leading forum for discussion of advances and new directions in non-impact and digital printing technologies. A comprehensive, industry-wide conference, this meeting includes all aspects of the hardware, materials, software, images, and applications associated with digital printing systems, including drop-on-demand ink jet, wide format ink jet, desktop and continuous ink jet, toner-based electrophotographic printers, production digital printing systems, and thermal printing systems, as well as the engineering capability, optimization, and science involved in these fields.
Since 2005, NIP has been held in conjunction with the Digital Fabrication Conference.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Terms & Conditions
- ingentaconnect is not responsible for the content or availability of external websites