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The trend towards a greater use of water as the solvent in flexographic and gravure printing inks has been influenced by a number of factors — the growing attention to environmental pollution problems, health and safety aspects, elimination of residual print odour in food packaging printing and conservation of organic solvents.

Some ten years ago, industry world‐wide entered a period of economic shortages and rising prices of petroleum, a situation making it essential for economy to be exercised in the use of organic solvents. This led to an upsurge of interest in water‐based products for use in printing and packaging. Interest was further stimulated by the increasing pressures from health and safety legislation and growing concern about environmental pollution problems. There were possibilities to develop alternative water‐based products to many solvent based inks, varnishes, lacquers and adhesives and quite a number of commercial successes were achieved and sustained. The following recession of the mid 1970's and depressed economic climate of recent years has done little to advance progress in water‐based inks. There were subsequently no major problems in availability of organic solvents and from this aspect no urgent needs to evaluate alternative water‐based products, unless real economic or technical advantages could be demonstrated.

Recent technical developments in the field of hydrodynamic sustentation, resulting from the unique techniques associated with the free‐body testing of self‐propelled dynamically similar models, has resulted in a great resurgence of interest in the use of water‐based aircraft in the National Defence. This paper describes some of the more important aspects of this research and discusses possible trends in military water‐based aircraft development. In addition to the military applications of the new high‐speed hydrodynamic developments, consideration is given to the development of transonic water‐based transport designs. Since the days of the famous flying‐boat clippers, over‐ocean transport has all but succumbed to the faster landplane. It is shown that an all‐jet water‐based transport, incorporating unusual safety and performance, is now a practical and logical development.

The purpose of this paper is to compare the thermal resistances between optimized gallium- and water-based heat sinks to show which one is superior.

Taking the thermal resistances of heat sinks as the goal function, an optimization process is programmed based on the genetic algorithm. The optimal channel/fin widths and the corresponding thermal resistances of gallium- and water-based heat sinks are obtained and compared with/without a laminar flow constraint. The analytic model and CFD method are applied in different situations to ensure sufficient accuracy.

The results show that in the laminar regime, the thermal resistance of optimized gallium-based heat sink is lower than the water-based counterpart in most cases, but the latter becomes better if it is long enough or the channel is sufficient high. Without the laminar constraint, the thermal resistance of the optimized gallium-based heat sink can be decreased by 33-45 per cent compared with the water-based counterparts. It is interesting to find that when the heat sink is long or the channel height is short, the optimal geometry of gallium-based heat sink is a mini gap.

This paper demonstrates that the cooling performance of gallium-based heat sink can be significantly improved by optimization without the laminar flow constraint.

The purpose of this paper is to prepare, characterise and evaluate nano-emulsions of copolymers of various compositions as eco-friendly binders for flexographic ink industry.

Various nano-emulsions of copolymers were prepared using styrene (St), butyl acrylate (BuAc), acrylic acid (AA) and acrylamide (AAm) monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), gel permeation chromatography (GPC) and transmission electron microscopy (TEM). A selection of copolymers was formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their viscosity, pH, degree of dispersion, water resistance and colour density.

It was found that the low viscosity of the prepared copolymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified polyacrylate-based latex with improved physico-mechanical properties were obtained. The prepared latexes were showed improving and enhancing in water resistance; gloss values, and the print density that ranged from 2.06 to 2.51 and the maximum gloss values (39 and 48) were also obtained. Also, these binders provide excellent adhesion properties for both the pigment particles and the base paper.

This study focuses on the preparation of new water-based copolymer nanoparticles and their use as eco-friendly binders for flexographic ink industry.

The ink formulations developed could find use in industrial-scale printing.

Eco-friendly environment ink formulations for printing on paper substrates are novel.

In recent years numerous pieces of environmental legislation have been introduced or will be introduced both in the UK and throughout Europe. The greatest environmental issue at the moment is the limitation of volatile organic compound (VOC) emissions. Water‐based coatings have been available for many years; their main application initially was for broad wall paints. More recently, water‐based coatings have come on the market for trim coatings. Although their performance for interior use is sufficient, but inferior to their solvent‐based alternatives, how do water‐based coatings for exterior wood perform? An alternative to water‐based technology is high solids. In a recent life cycle analysis (Ministry of the Environment in France) high solids alkyds have been shown to have low environmental impacts. In the study used for setting the criteria and thresholds for the European eco‐label for decorative paints and varnishes, a high solids alkyd developed by Cray Valley Ltd was put into the category having the lowest environmental impact together with water‐based paints. For the future of exterior coatings for wood, is the route to environmentally friendly coatings water‐based or solvent‐based technology?

The purpose of this study is to prepare, characterise and evaluate nano-emulsions of ter-polymers of various compositions as eco-friendly binders for flexographic ink industry.

Various nano-emulsions of ter-polymers were prepared based on Vinyl acetate, Vinyl Versatate, butyl acrylate, acrylic acid and acrylamide monomers by means of a conventional seeded emulsion polymerisation technique, using K₂S₂O₈ as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared, thermo-gravimetric analysis, gel permeation chromatography and transmission electron microscopy. A selection of co-polymers and ter-polymers were formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their rheological properties, pH, degree of dispersion, water-resistance and colour density.

It was found that the low viscosity of the prepared polymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified poly acrylate-based latex with improved physico-mechanical properties was obtained. The prepared latexes showed improved properties such as enhanced thermal stability and better water resistance. The effect of the emulsifier type on the properties of the resulting emulsion latexes and their corresponding films were investigated. Also, as the hydrophobic monomer increases, so does the colour density and increasing the binder ratio enhances the gloss values. The improving in gloss values were obtained and provide excellent adhesion properties for both the pigment particles and the base paper.

The study focusses on the preparation of new water-based ter-polymer nano-particles and their use as eco-friendly binders for flexographic ink industry. Ink formulations based on other different type emulsion polymers could also be studied to assess the applicability of the ink formulation system found for other binders.

The ink formulations developed could find use in industrial-scale printing.

Eco-friendly environment and low-cost ink formulations for printing on paper substrates are novel.

In Graz, Austria, the European Rotogravure Association (ERA) held a conference where several companies presented new developments in the printing industry including the latest developments in the field of water‐based ink systems. This paper discusses water‐based inks for gravure printing.

In this chapter the potential to use water-based Trombe walls to provide heated water for building applications during the summer months is investigated. Design Builder software is used to model a simple single-story building with a south-facing Trombe wall. The effects of using different thermal storage mediums within the Trombe wall on building heating loads during the winter and building cooling loads during the summer are modeled. The amount of thermal energy stored and temperature of water within the thermal storage medium during hot weather conditions were also simulated. On a sunny day on Toronto, Canada, the average temperature of the water in a Trombe wall integrated into a single-story building can reach ∼57°C, which is high enough to provide for the main hot water usages in buildings. Furthermore, the amount of water heated is three times greater than that required in an average household in Canada. The results from this work suggest that water-based Trombe walls have great potential to enhance the flexibility and utility of Trombe walls by providing heated water for building applications during summer months, without compromising performance during winter months.