A consortium of German and Austrian engineers from industry and academia has found a way to incorporate heating systems into moulds, effectively eliminating a costly step in the manufacturing process and potentially saving time and money on the factory floor.
Moulding is an important tool in the manufacturing toolbox. Plastic, one of the most valuable manufacturing materials, actually takes its name from the Greek meaning ‘to mould’ – but glass, metal and ceramics can be moulded too. There are three basic steps to the process: first, the feedstock – plastic granules, for example – is heated until it is pliable. Next it is extruded and placed into contact with the solid mould. Finally, it is cooled so that it sets hard, or ‘cures’.
But there is a problem here; pushing a material to a very high temperature and then reducing it down to a very low temperature is time consuming and energy intensive, making an otherwise simple process difficult. This issue was recognised several years ago by engineers in Germany and Austria, who came together at the initiation of Austrian SME ALPEX Technologies GmbH. Because the partners were based in more than one country, finding funding was a challenge - but in 2009, after some initial groundwork, they received support from the EUREKA Network to pursue what they thought might be a solution: heating and cooling systems incorporated into the moulds themselves. All partners were supported by national funding bodies in their respective country (see info-box).
ALPEX joined forces with powerful partners like the Airbus Group and Bundeswehr University Munich, as well as three other SMEs based in Germany: Neue Materialien Bayreuth GmbH, Quickstep GmbH and Schmuhl Faserverbundtechnik GmbH & Co. KG. Together they delivered the SPRAYFORMING project, which was conducted within the remit of EUREKA’s manufacturing Umbrella PRO-FACTORY. Its aim was to capitalise on the benefits of thermal spraying to create novel resource-efficient moulds for use with plastic. Thermal spraying allows parts – metal moulds in this case – to be fabricated using sprayed droplets of material, and therefore opens up the possibility of metal moulds with heating and cooling elements right beneath the surface.
"SPRAYFORMING was a consortium of highly competent partners." – Mag. Bernhard Rittenschober
Work on the project was divided into five work packages, each tackled by one of the industrial partners. ALPEX, however – despite being one of the smaller companies involved – took a leading role, developing base models, mould materials and milling of master models for the metal moulds, as well as computer-assisted design interfaces for controlling manufacture. They also set up test programs and trials together with the robot supplier, and completed the engineering and manufacture of the moulds. Mag. Bernhard Rittenschober was Project Manager for ALPEX at the time, and recalls the positive atmosphere in which the collaboration was conducted: “I enjoyed work in the consortium very much. As is often the case with research projects, I met nice people and had a good time both in working together as well as intercultural exchange. SPRAYFORMING was a very friendly consortium of highly competent partners.”
“This was a very positive project where all partners learned a lot”, recalls Dipl. Ing. Dietrich Jonke, Airbus’ representative on the project. “We at Airbus – who were simultaneously the project leaders and the end-users – benefitted immensely, building a better mould and getting an insight into the technology involved.” Going forward, aeronautics manufacturers like Airbus are likely to rely increasingly heavily on moulded carbon fibre-reinforced plastic as a material that offers unbeatable toughness by weight. The project partners therefore expect that interest in their novel moulding tools will grow in the near future, expanding beyond its current use within Airbus to serve other manufacturers working with plastic.
Overall, this was a project that produced real advances in both near-market and fundamental science – and its results caused widespread excitement in the industry. “The technology we developed is still spreading through the world of carbon composites. Customers, development partners, and universities regularly contact us about the technology, and are interested in the outcomes or the applications.” What is more, several new co-operations based on the dissemination and distribution of this developed additive manufacturing technique have been initiated since the completion of SPRAYFORMING. “This project gave ALPEX a lead in technology which we will now use in future development”, Rittenschober summates.