The Injection Stretch Blow Moulding (ISBM) process is the main method used to mass-produce PET bottles for the carbonated soft drink and water industries, an industry worth 6 billion pounds in the UK. The process begins with injection moulding of a preform which is subsequently re-heated above its glass transition temperature and formed into a hollow mould by a combination of axial stretching by a stretch rod and radial stretching by internal air pressure. The existing industrial state of the art in the process involves trial and error approaches on a single cavity ISBM machine to determine appropriate machine settings for industrial production. This process is wasteful in terms of time, energy and material and restricts processors in their ability to lightweight containers which for both economic and environmental reasons is a major goal of the industry. Researchers are developing numerical simulations to try and overcome this empirical approach and replace it with a more scientific method whereby one can predict the process conditions and their effect on material thickness distribution and final material properties in advance, thus enabling the optimum preform design and process conditions to be obtained. However success to date has been limited. One of the major causes is that current simulations do not model the correct physical behaviour of the transient pressure history inside the preform as it is inflated into the bottle mould. The project will build on recent results from a European project (Apt_Pack) in which it was demonstrated that one of the most fundamental process variables in the ISBM process is the mass flow rate of air that enters the preform as it inflates. It is this that is ultimately responsible for the pressure inside the preform and thus primarily controls the rate of inflation of the preform, the final thickness distribution and the properties of the formed container. The transient pressure history depends on the supply pressure, the mass flow rate of air and the rate of inflation of the preform. As a result, the only sensible approach to modelling this is to have a coupled fluid structure interaction whereby the pressure is calculated based on the volume of the expanding preform and the mass flow rate of air entering the preform. The main aim of this project will be to conduct a parallel experimental and modelling program to understand and accurately quantify the air flow within the injection stretch blow moulding process and evaluate how it can be best incorporated within an ISBM process simulation.

Polymers, because of their properties and ease of processing into complex shapes are among the most important materials available to us today and the polymer industry makes a major contribution to the UK economy (18 billion per year). An exciting new family of materials are polymer nanocomposites (NCs), in which particles with nanoscale dimensions are dispersed in the polymer. The benefits of NCs derive primarily from the exceptionally large amounts of particle surface area that can be achieved for a small addition of particles (e.g. 5% by weight). Thus they offer dramatic improvement in material performance with significant increases in mechanical and gas barrier properties. The user of such a material therefore gets a more effective product (or one containing less material for the same effectiveness). It is well recognised that the nanoparticle-polymer interface/chemistry is a critical parameter in determining the degree of dispersion of particles in a nanocomposite and that the interfacial properties have a significant influence on nanocomposite performance. In recent times, however it has become apparent that the processing route by which the nanoparticle-polymer mixture is formed into a final product is an equally important aspect of NC manufacture and this is the area on which we will focus in this proposal.The principal aim of the proposed project is therefore to achieve a fundamental understanding of the interactions between material formulation, processing and properties of polymer nanocomposites and to apply this to the development of proof of concept applications which provide generic processing information for industry and academia alike. The work will include statistically designed experimental studies using pilot scale polymer processing equipment and validation trials on industrial scale equipment. Parameters to be studied include extruder shear and temperature profiles, screw design, additives such as anti-oxidant, post extrusion deformation such as biaxial extension and cooling rates. We will characterise the materials in terms of structure, mechanical, thermal and barrier performance in order to link process to structure and structure to performance.We will utilise the combined processing, characterisation and analytical skills and facilities existing in Queen's University Belfast (QUB) and the University of Bradford (UoB), partners who have worked together successfully on large collaborative projects, in the past and currently, and have an excellent national and international track record in polymer processing research.

Polymers, because of their properties and ease of processing into complex shapes are among the most important materials available to us today and the polymer industry makes a major contribution to the UK economy (18 billion per year). An exciting new family of materials are polymer nanocomposites (NCs), in which particles with nanoscale dimensions are dispersed in the polymer. The benefits of NCs derive primarily from the exceptionally large amounts of particle surface area that can be achieved for a small addition of particles (e.g. 5% by weight). Thus they offer dramatic improvement in material performance with significant increases in mechanical and gas barrier properties. The user of such a material therefore gets a more effective product (or one containing less material for the same effectiveness). It is well recognised that the nanoparticle-polymer interface/chemistry is a critical parameter in determining the degree of dispersion of particles in a nanocomposite and that the interfacial properties have a significant influence on nanocomposite performance. In recent times, however it has become apparent that the processing route by which the nanoparticle-polymer mixture is formed into a final product is an equally important aspect of NC manufacture and this is the area on which we will focus in this proposal.The principal aim of the proposed project is therefore to achieve a fundamental understanding of the interactions between material formulation, processing and properties of polymer nanocomposites and to apply this to the development of proof of concept applications which provide generic processing information for industry and academia alike. The work will include statistically designed experimental studies using pilot scale polymer processing equipment and validation trials on industrial scale equipment. Parameters to be studied include extruder shear and temperature profiles, screw design, additives such as anti-oxidant, post extrusion deformation such as biaxial extension and cooling rates. We will characterise the materials in terms of structure, mechanical, thermal and barrier performance in order to link process to structure and structure to performance.We will utilise the combined processing, characterisation and analytical skills and facilities existing in Queen's University Belfast (QUB) and the University of Bradford (UoB), partners who have worked together successfully on large collaborative projects, in the past and currently, and have an excellent national and international track record in polymer processing research.