Next Generation Inkjet Technology: Aims and Focus
- Bring together the leading manufacturers, users, and researchers in inkjet technologies
- Define a rolling programme of research that meets the needs of the industry in the medium and long term
- Allocate resource to those areas of research defined within the overall programme, among the academic partners in the Universities of Cambridge, Durham, Leeds, Manchester and Aberystwyth
- Create a central nucleus to support the infrastructure of the Centre and undertake management and coordination
- Conduct a programme of dissemination to the wider industrial and academic community
- Provide the facilities and infrastructure that enables companies to sponsor work of specific interest to the individual company.
Focus for Investigations
- Characterisation of fluids - Characterisation of how the properties of fluids affect the key properties of droplet formation and ejection. This will include study and modelling of the effects of shear and extensional viscosity; visco-elasticity; surface tension (including rate-dependent effects); velocity of sound; solvent evaporation; bubbles; dissolved gases; particles and agglomerations. Quantitative design rules are required so that the ink-jetting behaviour of fluids can be predicted from measured fluid properties.
- Measurement techniques for inkjet fluids - Instrumentation will be developed for measuring the relevant properties of inkjet fluids so as to allow performance prediction to the accuracy required to reach the Technology Performance Targets. Sponsor companies wishing to have the instruments will pay the costs.
- Droplet flight - Characterise the influences on droplets in flight that affect the accuracy of droplet placement on stationary and moving surfaces. Such interactions include aerodynamic interactions between droplets in flight and the movements of air caused by droplet streams and the motion of print-head and substrate. In the case of continuous inkjet electrostatic interactions will also be included. Strategies will be sought to control these influences.
- Droplet impact. Characterise the fluid properties, impact parameters and surface properties that affect the spreading, splashing, coalescence and interaction of droplets after impact. Strategies will be sought to control these influences.
- Fluid design. Provide design guidance on how fluids whose rheology is not ideal for ink-jetting may be modified to provide improvement. This work will start later in the programme when more is known about the rheology.
- Design rules for nozzles. Characterisation of how the physical and chemical properties of nozzles affect the key properties of droplet formation and ejection such as: direction of flight, velocity, droplet size, formation and flight of satellites, break-up length (for continuous inkjet) and failure modes. Quantitative design rules are required to relate the gross dimensions, tolerances, surface finish and surface properties of the nozzles to these properties. The immediate environment of the nozzle will be included as necessary.
- Measurement techniques for nozzles. Techniques will be developed for measuring the relevant properties of nozzles.
- Manufacturing processes. Work with the manufacturers and users to reduce manufacturing variation in nozzles and in fluids, and to identify key issues in piezo-material reproducibility. This work will start later in the programme when initial work has been undertaken on nozzle and fluid design.