Polymer Processing Research Centre

By Mark McCart & Mark Kearns, Queens University, Belfast

Research in various aspects of polymers, including their processing, has been carried out in the School of Mechanical & Aerospace Engineering at Queen’s University, Belfast for over 25 years. During this time substantial investment has been made in establishing and maintaining state of the art processing and analytical facilities.
Building on the long established processing expertise at QUB in rotational moulding and polymer extrusion and extending into the complementary processing technologies of injection moulding, blow moulding and thermoforming, the Polymer Processing Research Centre, PPRC, was established in 1996 with assistance from the local development agency Invest NI (formerly IRTU) to carry out and support leading edge, industrially exploitable, fundamental and applied R&D to demonstrably improve industrial competitiveness.

In 2002 there followed the establishment of the Medical Polymers Research Institute MPRI which provides a forum for collaborative work between Mechanical and Aerospace Engineering and colleagues from Pharmacy concentrating on research in the field of new polymeric materials, products and processes for the medical devices and drug delivery industries. In addition to working directly with industry in carrying out R&D as well as knowledge and technology transfer programmes and the provision of training courses, staff in the Centre work closely with academic colleagues in the Polymers Research Cluster on a wide range of research programmes.

Not only are short term, direct contract research and development activities undertaken in its two industrial supportive Research Centres, the Polymer Processing Research centre (PPRC) and the Medical Polymers Research Institute (MPRI), there is also a wide range of industrially applicable research being undertaken at QUB in the Polymers Research Cluster in the School of Mechanical and Aerospace Engineering. A total of around 70 people comprising academics, contract technical, support and research staff, together with PhD students, are engaged in polymers research at the University. The work undertaken is broadly follows four principal themes of Polymer Processing, Modelling and Control, Nanomaterials and Medical Biomaterials.

As well as undertaking strategic multidisciplinary research into the processing of materials, the University has a strong reputation in the modelling of and development of high performance polymeric materials. Ongoing investment in processing, analytical and testing facilities means that Queen’s is equipped to undertake high quality applied and fundamental research, reflecting the needs of the polymer industry in the UK and abroad.

Within this industrially relevant research portfolio there is an interest in sustainable manufacturing much of which has been or is currently being commercialised. Below are examples of how the PPRC is helping industry across Europe develop novel, new and innovative sustainable manufacturing techniques:

Case Study: Micromelt Project
The Micromelt Project aims were to increase product quality and reduce energy consumption in the rotational moulding process by improving both heating and mould cooling, and are partially funded by the EC Framework programme. Partners in the project included research institutions Pera, Fraunhofer TEG and Queens University Belfast (QUB) as well as trade associations the British Plastics Federation (BPF), The Association of Rotational Moulders of Central Europe ( ARM- CE) and the Association of Rotational Moulders of Ireland ( ARMI) as well as SMEs in Germany, Sweden, Italy, Ireland and the UK. The concept was to utilise microwave heating and internal water cooling to reduce energy requirements and cycle times. This leads to significant cost savings.

Traditionally, rotational moulding involves rotation of a mould filled with polymer in an external oven. This process is very energy intensive. It had been shown by computer modelling from Fraunhofer that microwave heating methods as opposed to conventional hot gas heating can greatly reduce processing time. This was confirmed by practical work at Pera on test samples. Suitable test moulds were developed to aid the heating process, and a choice of material for optimal performance made. Following benchmarking of the conventional rotational moulding process by QUB, a prototype rotomoulding tool was designed by Pera which optimises design for efficient microwave transmission. A prototype industrial microwave oven was designed and built by Fraunhofer and positioned on the QUB Ferry Rotomoulding machine – extensive trials indicate that with further optimisation >25 % reduction in cycle times through the use of microwave heating technology is possible as well as an energy cost saving of > 24% due to the high efficiency of the microwave coating.

Work by QUB also made significant progress in improving the cycle time and efficiency of the cooling cycle. A prototype, internal mould, water spray cooling rig has been shown to significantly reduce the cooling stage of a number of test tools. Industrial trials at rotomoulding factories in Germany, England, Ireland and Scotland showed considerable cooling stage cycletime savings. An added benefit was the subsequent reduction in part warpage due to the ‘balanced’ internal and external mould cooling – improving part quality, reducing scrap and jigging times.

The technology developed during the Micromelt project appears to have serious potential for reducing cycle times and energy costs during a rotational moulding cycle with the potential for >40% reduction in overall cycles times through the use of both technologies.

Case Study: Badana Project
Under the European Union’s Seventh Framework Programme, the PPRC at Queens University, Belfast secured a research grant to conduct applied and fundamental research in the field of combining natural banana plant fibre in rotational moulded plastic products.
The 2 year ‘Badana’ Project began on July 1st 2009 and is a truly pan-European project with the research conducted on behalf of companies in the UK, Spain, Germany, Netherlands and Eastern Europe.

The main objective of the ‘Badana’ project is to develop and validate novel procedures for the extraction of truly sustainable, natural fibre from waste matter derived from banana cultivation in the EU that does not displace food production. The fibres will be used to develop innovative, sustainable rotationally moulded and injection / press moulded thermoplastic composite products.

Almost 20% of the bananas consumed in Europe are produced in the Canary Islands with around 10 million banana plants are grown annually in Gran Canaria alone. In the past, the banana plant waste was used as a support element for arable plants as well as cattle fodder, basket weaving, etc. Today, however, these vegetable wastes are deposited in ravines where they become decomposition material. An estimated 25,000 tonnes per annum of natural fibre is found in this waste. With this in mind one of the largest Banana plantation cooperatives in the Canary Islands approached the local University to see if it were possible to do something constructive with this waste product. Queens were approached because of their expertise in Rotational Moulding and strong links with a number of Universities in Spain (University of Las Palmas / University of Zaragoza) that are involved in the project.

MARK MCCART & MARK KEARNS
Polymer Processing Research Centre
Queens University, Belfast
Tel: +44 2890974700
Fax: +44 2890660631
Email : pprc@qub.ac.uk
Web: www.qub.ac.uk/pprc

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