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In rotogravure printing, engraved cells collect ink from a bath and then release it onto the substrate forming a series of printed dots that comprise the printed image. The purpose of this work was to explore the ink release in the rotogravure process to improve its predictability and scientific understanding. Two complimentary approaches have been investigated, an empirical approach embodied into Artificial Neural Network models and a numerical physical approach based on Computational Fluid Dynamics modelling. The Artificial Neural Network approach was based on a statistical correlation of experimental data on cell geometry with optical properties of the resulting print. The developed A.N.N. models were able to accurately predict the effect of cell geometry on ink release, outperforming traditional modelling techniques such as polynomial regression fitting techniques. The models were found to be practical and suitable to integration into manufacturing environments. The A.N.N. modelling highlighted the need for improved cell geometry data; to facilitate this, new software was developed for the automatic and accurate geometric characterisation of the engraved cells from interferometric profiles. A Computational Fluid Dynamic model of the ink release was successfully developed; the process was described as the evacuation of a Newtonian liquid from an axisymmetric cavity, showing the progressive splitting of the ink and retention of ink in the cell. This model is the first that takes into consideration the dynamic contact angle in the analysis of ink release from a cavity. The reliability of the numerical method and of its dynamic contact angle model was verified by comparing specifically designed models with experimental and literature data. The developed evacuation model shows the importance of the evacuation speed on the dynamics of the process and the critical importance of dynamic contact angle.

Liquid residues and moisture within the packaging is a big challenge to fresh food packaging, particularly for liquid-exuding food, such as meat, fish and poultry. The free-moving liquid (exudate) in the bottom of plastic food trays adversely affects the safety, quality and presentation of packaged meat products. However, the current food packaging solutions to isolate meat exudate including the addition of absorbent meat pads are not efficient, restricting the recycling process of plastic packaging and increasing plastic waste that ends up in landfill and oceans. This work reports the development of innovative plastic packaging solutions capable of effectively isolating the meat exudate within the packaging itself, ensuring more sustainable and recyclable plastic food packaging. The developed solutions include three innovative technologies:Geometry modification of liquid-holding recesses integrated into plastic food tray. The raised rims of the modified recesses act as capillary geometrical valves, enhancing the liquid pinning and pressure barrier. This results in an approximately 2.8 times increase in liquid retention capacity of the recesses, compared with a design without raised rims. Surface modification of liquid-holding recesses with oxygen plasma treatment. The localised plasma treatment of recess walls implants polar oxygen groups on the wall surfaces. This induces contrast in the surface wettability between plasma treated walls and untreated outer edges of the recesses, increasing their liquid pinning and pressure barrier, thus their liquid retention capacity. The functionality induced by plasma treatment was reserved long enough (> 60 days) for increasing the liquid retention capacity of ~2.2 times in comparison with untreated recesses. Surface modification of open-cell polymeric foam with oxygen plasma treatment. The plasma treatment results in improving the surface wettability of foam porous structure due to introducing polar oxygen groups on the pore walls. The improved wettability increases the sucking capillary pressure acting on the foam pores, allowing for higher liquid uptake and absorption of open-cell foam. The plasma treatment has sufficiently long effect on wettability improvement (> 60 days) to be used for the treatment of plastic foam packaging with an increase in the liquid absorption capacity of ~8 times. This work has led to developing innovative and sustainable plastic meat packaging for effective self-isolation of meat exudate. The plastic packaging trays incorporated with recesses are fully recyclable with liquid retention capacities comparable to the conventional absorbent meat pads. Therefore, plastic food packaging with liquid isolation capability can be manufactured with no need for additional absorbent components. The plasma treatment of open-cell polymeric foam can also replace the use of chemical wetting agents for facilitating liquid absorption, protecting human health and environment.

This doctoral thesis is a research study into the thin film manufacture and applications ofglassy carbon. The aim of this research was to explore photonic curing as a novel rapidmanufacturing method to produce glassy carbon thin films and to expand the applicationsof glassy carbon in energy storage and printed electronics. Photonic curing was explored as a rapid method for producing glassy carbon coatings, reducing processing time from ~20 hours for conventional thermal processing down to ~1 minute. For both photonic and conventional thermal produced coatings, Raman spectroscopy and primary peak XPS data showed sp2 bonded carbon, indicative of bulk glassy carbon. XPS analysis indicated greater sp3 content at the immediate surface (5-10 nm) for photonic cured carbon compared with thermally cured carbon, likely due to the local environment (temperature, atmosphere) around the surface during conversion. The produced coatings were resilient, highly smooth, with no evidence of surface defects. The ability to rapidly manufacture glassy carbon coatings, by way of photonic curing, expands the potential window of applications of glassy carbons for high volume applications such as coatings for energy storage, rapid manufacture of complex electrically conductive shapes, and the opportunity to use temperature sensitive substrates. Photonic cured and thermal carbonized glassy carbon thin films were explored as electrode active materials. The glassy carbon thin films from both manufacturing methods showed comparable specific capacitances to one another and to the use of porous glassy carbon as a supercapacitor active electrode material in literature. Screen printed glassy carbon structures were made to explore potential applications for glassy carbon in printed electronics and sensors. These prints yielded electrical conductivities comparable to carbon based conductive inks, potentially expanding the applications window for glassy carbon for electronics devices with high chemical resistance, low reactivity and high thermal stability. Screen printed glassy carbon temperature and salinity sensors were produced and tested, glassy carbon as a temperature sensor yielded promising results whereas glassy carbon as a salinity sensor did not have a significant response with the investigated parameters.

The increased adoption of wind energy is an important part of the push towards a net zero-emission economy. One obstacle that stands in the way of a higher rate of wind energy adoption is the interference that wind turbines cause to nearby radar installations. Wind turbines negatively affect the performance of nearby radar sites in a variety of different ways. Almost all types of radar are affected in at least one of these ways. In order to understand the degree to which an object such as a wind turbine interacts with radar, it is important to have detailed radar cross section (RCS) data for the object. In this work, a novel, low-cost, scale model radar cross section characterization system is presented with various advantages over traditional designs. This system was used to characterize the RCS of the novel Crossflow wind turbine. Additionally, work has been carried out on the characterization of metamaterial absorber coatings that can be applied to new and existing turbines for the purposes of reducing their radar cross section and the degree to which they cause radar inter-ference. The works presented can be leveraged to reduce concerns around radar interference from wind turbines, as well as to iteratively generate ge-ometries with lower radar cross sections for the aviation and infrastructure sectors, ultimately accelerating the pace of wind energy adoption and the move towards a net zero-emission economy.

In line with the latest innovations in the packaging field, this joint project aims at implementing new and innovative micro- and nanoparticles for the development of active and intelligent packaging solutions dedicated to food and medical packaging applications. More specifically, the project combines two major developments which both falls within the scope of active and intelligent packaging. In this work, a specific focus was given to the development of an antibacterial packaging solution and to the development of smart gas sensors. The antibacterial strategy developed was based on the combination of two active materials - silver nanowires and cellulose nanofibrils - to prepare antibacterial surfaces. The formulation as an ink and the deposition processing has been deeply studied for different surface deposition processes that include coatings or screen-printing. Results showed surfaces that display strong antibacterial activity both against Gram-positive and Gram-negative bacteria, but also interesting properties for active packaging applications such as a highly retained transparency or enhanced barrier properties. Regarding the second strategy, gas sensors have been prepared using a combination of Copper benzene-1,3,5-tricarboxylate Metal Organic Framework and carbon-graphene materials, deposited on flexible screen-printed electrodes. The easy-to-produce and optimized sensors exhibit good performances toward ammonia and toward humidity sensing, proving the versatility and the great potential of such solution to be adapted for different target applications. The results of this project lead to innovative solutions that can meet the challenges raised by the packaging industry.