05 | 2010

Report
Photovoltaic Panel
www.polymer-pilotplants.com
www.iwmh.fraunhofer.de
Optimized Processing of
Natural Materials in Pilot Scale
The Fraunhofer Pilot Plant Centre for Polymer Synthesis and Processing (PAZ) in Schkopau, Germany, is a joint initiative
of the Fraunhofer Institutes for Applied Polymer Research (IAP) and Mechanics of Materials (IWM) in Halle. Working
together with companies from all over the world tailor-made complete solutions in pilot scale are developed from monomers
by way of synthesis and polymers are used to produce finished and tested components.
In the processing area the development of materials and processes such as compounding and extrusion using, for example,
natural fibres such as wood, flax, sisal or hemp for filling and reinforcement functions are carried out on different industrial
scale twin screw extruders. Custom-designed, highly filled, natural fibre compounds and components produced from them can
be made - for example to increase material strength, stiffness and impact strength. Samples of such compounds in pellet form
can be produced for test purposes in quantities up to a tonne or more.
Optimising of the mechanical properties of wood/plastic composites (WPC) for injection moulding is a core competence of the
Pilot Plant Centre. Typically WPC materials have a high strength and stiffness but they are also very brittle in regard to impact
stress. For instance it has been possible, by the addition of further innovative fibres in small amounts, to increase the impact
strength of materials with a wood fraction of 40% by more than 130%, compared to a ‘standard WPC’ at room temperature. At
a temperature of -25°C the improvement was even more than 160%.
Model system of a polymer based photovoltaic module
For injection moulding processes an injection moulding machine is available with a clamping force of 200 tonnes, or
alternatively two innovative injection moulding compounders (compounding and injection moulding in one process step) with
clamping forces of 1300 and 3200 tonnes. Components with shot weights of 50 up to 9000 grams can be produced. In addition,
to optimise the processing conditions and mechanical properties of natural fibre composites, a further field of research covers
biopolymers such as PLA.
A focus on polyurethane processing (clear coat moulding technology and the manufacture of highly transparent, thin surfaces)
is new at the Pilot Plant Centre. The aliphatic materials being investigated offer a wide spectrum of adjustable mechanical
properties and represent a special field in the processing of polyurethanes. Particularly in regard to photovoltaic applications
the use of bio-based polyurethane is also being investigated. These materials, consisting of a polyol derived from renewable
vegetable oils, can help to reduce the amount of fossil fuel based polyurethane products and improve the environmental profile
of these materials over the whole life cycle. The current investigations address the processing parameters as well as the
resulting properties, e.g. the heat and weather stability.
The Fraunhofer Pilot Plant Centre is available to support the industry, e.g. by producing sample lots and pre-series in pilot
scale up to the point of introduction onto the market, as well as for mould and material testing, for example complex testing
of material and component properties.
20 bioplastics MAGAZINE [05/10] Vol. 5