EngD project: / Anilox cell geometries for printable electronics and flexible packaging
Theme: / Packaging
University / Centre of Excellence: / Swansea University
Proposed Academic Supervisor: / Prof. T. Claypole
Proposed Industrial Supervisors:
Sponsor: / Advanced Printing Network
Background:
The printing industry for many centuries had been a driver in the social and industrial revolution. Today, printing is a high volume, precision manufacturing process capable of accurately, selectively covering and curing as many as 15 materials up to speeds capable of covering a football pitch in 90s. Printing has had to adopt new materials and technologies to improve economic performance and meet the increasingly strict environmental legislation. Flexographic printing is one of the rapidly growing technologies primarily in flexible packaging, a market which last year had an estimated value of $263M. This project is supported by a consortium of leading print companies and their suppliers.
Flexographic printing is a web process where the raised areas on a digitally exposed photopolymer plate transfer the image or functional feature selectively to the substrate. The anilox is an engraved cylinder at the heart of the process that meters the transfer of ink to the surface of the plate. Laser engraving can produce a range of internal profiles that will affect the ink release and also will interact with ink parameters such as pigment size and distribution. The depth of the cell combined with the volume gives an approximation to the aspect ratio of the cell. However, comparing aspect ratios, does not allow for the geometric differences produced by different engraving strategies. While it has been suggested conventional surface roughness parameters could be used to access the deviation from an “ideal” cell internal geometry, the major issue with this is the definition of ideal and that with certain engraving configurations and inks, certain engraved features may play no role in the ink release.
Objectives/Scope:
The objective of this project is to develop the underpinning science and key definitions that can be used to describe the ink carrying characteristics of anilox cylinders engraved. It will include the study of the ink transfer from the anilox with a view to identifying the key anilox parameters that effect ink release and how these interact with the physical properties of the ink, (viscosity, pigment size and shape, etc) and print process parameters. There will be multiple benefits to the flexo printing industry of this project including an understanding of the interaction of inks with anilox structures. This will be particularly important for printing of special effects, security and functional inks, such as for printed electronics. The long term aim is not to define the optimum anilox geometry, as this will be influenced by the application, but to produce an analytical model that would enable the ink release to be predicted based on measurements of the anilox and ink properties.
Suitable Candidates:
This project is suitable for graduates with a 2:i degree in engineering, Physical sciences or Mathematics
For general information contact Dr David