K-PROFI 1-2 2015:
Review on IIMC 2014 in December 2014 at IKV Aachen –
Next IIMC on September 30 – October 1, 2015
Lightweight construction, optics, variothermal cooling, foaming and simulation
International Injection Moulding Conference (IIMC) looks at the latest trends in injection moulding for vehicle applications
At the premiere of its International Injection Moulding Conference (IIMC) at the beginning of December 2014 in Aachen, the Institute of Plastics Processing (IKV) looked at many aspects of the injection moulding technology, but with a special focus on automotive applications. The head of the Institute, Prof. Dr.-Ing. Christian Hopmann, and 15 other speakers from Germany, France, Japan and the United States talked about the latest trends and discussed some of the current technologies: variothermal temperature control, foaming, optical systems and generative production processes. Of the 100 or so delegates attending the two-day program, nearly two thirds were from abroad, 20 of them from Asia. Here is a brief summary.
Dipl.-Ing. Markus Lüling, Chief Editor of K-PROFI
Dr.-Ing. Peter Urban, deputy head of the Aachen Institute of Automotive Engineering (ika), kicked off the conference by outlining the main challenges currently facing vehicle development and their consequences for plastics technology. The efforts to reduce CO2 emissions and to deploy alternative drive systems were naturally generating significant potential for plastics technology in the lightweight construction of the vehicle body and outer skin. He said there was also strong demand for crash-deformable battery packs with a thermoset injection-moulded cover and local reinforcements that were suitable for large-volume production. High-pressure tanks for gas fuels are another interesting application. He added that considerable savings can be achieved by aerodynamic optimisation, for example, on trucks, where savings of up to 2.2 l/100 km were possible with the aid of side and rear elements. However, said Urban, a permit to modify the front and rear sections would make it necessary to increase the maximum permitted length of the truck above 16.50 m. Urban also sees promising opportunities for plastics technology in the trend towards automation: A big challenge for self-propelled systems comes from the many different sensor systems, especially optical sensors and their integration into the outer skin of the vehicle. It is generally the plastics engineer who is called on to find a solution. On top of this, he said, potential also exists in the field of "connected driving" with the levels of navigation, guidance/assistance systems and stabilisation. Current topics include satellite navigation, further electrification, the integration of the transmission unit and the chassis through decentralised drive systems on the wheels, and the redesign of operating elements. All this is taking place against the background of a globally expanding market for passenger cars. In 1985, only nine market segments were identified, while today there are more than forty. All of them are affected in their own way by the often conflicting key requirements of effectiveness, prestige, cost and driving enjoyment, so that this customisation will result in an increasing number of smaller production batches. Realistically, the long-term perspective of an accident-free and emission-free driving experience with intelligent assistance systems, sustainable lightweight construction and efficient energy and heat management means more than just solving the CO2 problem and the demands on automation. "Resolving the contradictions between driving enjoyment, safety and environmental pollution will remain a complex task," said Urban.
Optical systems offer potential for thermoplastics and LSR
Prof. Dr.-Ing. Christian Hopmann, Director of IKV, presented the main areas of research in injection moulding and mould-dependent fibre composite technologies at his Institute, and also took a look at the latest trends in plastics technology. Driven by recent developments in lighting technology, modular mould systems for the multi-step and multi-layer injection moulding of thick-walled optical parts had recently been arousing increasing interest. The variety of strategies for the production of thick-walled parts, ranging from classic compact injection moulding to the injection of several layers one after the other, offer options for virtually any dimension and geometry. Hopmann also underlined the potential of LSR in lighting applications. Its excellent UV stability and heat resistance makes it ideal for use in transparent optical systems. This aspect was also highlighted by Heiko Bayerl from LSR manufacturer, Momentive Performance Materials. The low viscosity of LSR, said Hopmann, also made it possible to directly mould liquid silicone onto LED boards.
Variothermal processes and foaming still being underestimated
Hopmann also underlined the potential of processes supported by dynamic temperature control: Creating antireflection finishes, overcoming long flow paths and reducing the consequences of weld lines were only a few examples of the many advantages. Comparative tests on liquid temperature control, laser heating and inductive heating are aimed at determining the optimum variothermal temperature control strategy from both a technical and an economic point of view. Moving on to the topical subject of lightweight construction, Hopmann sees greater overall potential in the foaming of plastics for weight saving than in using carbon fibre-reinforced plastics (CRP). He thus put into perspective the generally held opinion that fibre-reinforced plastics alone can reduce weight significantly. At present, he said, the widespread use of foam structures is being hindered by the still limited simulation ability of the various foaming processes and difficulties with the calculation and structural analysis of foamed parts. Simulating the behaviour of a gas-loaded melt is not easy, but is acknowledged as a success criterion and therefore the subject of intensive research.
Dominique Manceau, head of the Innovation department at Plastivaloire, underlined the advantage of inductive heating of the moulding tool for the representation of a variothermal foaming process. Steve Braig, CEO of Trexel, which supplies the "Mucell" physical foaming process, reported on a joint project with 3M, in which hollow glass spheres in the physically foamed polyamide 6 melt had led to improvements in the mechanical properties as well as weight reductions. The addition of glass spheres had also produced a minor improvement in surface quality, although it was still nowhere near Class A quality.
More simulation for shorter time to market
The possibilities of functional integration with injection moulding, said Hopmann, were still far from exhausted. Intelligent strategies would still be needed to enhance efficiency with robust processes. With the simulation tools now available and currently at the optimisation stage, it was a case of speeding up development and the start-up of production. This fact was also underlined by Florian Petzold, head of Osram’s Technical Center Molding in Munich: Without simulation, there would be no chance of achieving the fast time to market required today.
Generative production methods and 3D printing
No technical conference today would be complete without a discussion of the generative production processes. Aachen was no exception. Prof. Hopmann sees much greater potential for the industrially used 3D technologies in mould design for injection moulding and the sintering processes for mould inserts than for the 3D generation of plastic parts, even though this process may be worthwhile in individual cases. He mentioned the existing limitations of the 3D printing of plastic parts compared with the established moulding processes: Although the range of materials was constantly increasing, it was still restricted to a relatively small number of unreinforced materials. Furthermore, in his view, the non-recognisable molecule orientation and the limited build velocity are inhibiting the additive manufacture of plastic parts.
IIMC 2015 at the end of September
Hopmann announced the dates for the second IIMC, namely September 30 and October 1, 2015. This year’s conference would have a different application focus than the automotive industry. From 2017, the International Injection Moulding Conference would then be held every two years, always in the spring of the uneven years to complement the International IKV Colloquium, which reports on IKV’s activities in all fields of plastics technology and is traditionally held in the spring of the even years.
A bold step was rewarded
The first International Injection Moulding Conference (IIMC) staged by the Aachen Institute of Plastics Processing (IKV) was watched very critically by other conference organisers. After all, a technical injection moulding conference held in English and targeting visitors outside the German-speaking countries could be seen as an experiment. Prior to this, few such events had been risked. Looking back, there can be little doubt that the IIMC was very well received. Some 100 participants from all continents – apart from Africa – came to Aachen, with nearly two thirds of them from outside the German-speaking region, and twenty from Asia alone. It was also interesting to note that they represented all stages of the value chain, from producers and machine builders to converters and OEMs. Over the two days, the delegates heard many high-quality presentations. The integrated visit to the IKV injection moulding and composites pilot plants and laboratories proved to be a particular highlight for the international visitors. The enormous interest shown by the guests in the European technology standard and the presentations by leading technology suppliers was obvious for all to see. The Director of the Institute, Prof. Christian Hopmann, wants to further increase the international reputation of the IKV as a renowned teaching and research institute for plastics technology, and also further strengthen its position as a meeting point for technology communication in matters of plastics engineering. The first IIMC met both these aims, and was the just reward for a bold step. The next conference in autumn will show whether the concept can become successfully established in the longer term. Markus Lüling
Source: K-PROFI, 1-2/2015