Covestro, KraussMaffei and IKV Win 2017 FSK Innovation Award

Significant Progress in Pultrusion, Tremendous Potential for Efficient Serial Production of Composite Components

Covestro, KraussMaffei and the Plastics Processing Institute at RWTH Aachen University were recognized with the 2017 FSK Innovation Award for polyurethane. This award was presented by the Specialist Association of Foamed Plastics and Polyurethanes (FSK) to honour the achievements of stakeholders promoting wider industrial use of pultrusion with polyurethane resins. The jury panel for the award, presented in the "Technology - Processing and Chemistry" category, commended the method's cost-effectiveness for processors and the collaborative approach shown in the project. The award ceremony took place at the International FSK Expert Polyurethane Conference 2017 in Gurten, Austria.

Tremendous Potential

Pultruded composite components had already proven their success in thermally insulated window frames and in reinforcing rotor blades for wind turbines. The process offers tremendous potential for continuous manufacturing of composite components, but has not been widely used to date due to insufficient industrialisation levels. Working in close collaboration, the three partners developed the chemistry, technology and process to significantly increase both efficiency and product quality in both the process and the product. Processors can now reduce costs significantly compared to the previous method.

Highly Automated Flexible Turnkey Systems

KraussMaffei's new iPul machines are the first turnkey systems to source system, process and mould technology from a single supplier. Critical process parameters such as output speed and pulling ratio are controlled centrally. In the new systems, fibres are now impregnated in a closed injection chamber with a metering unit rather than in an open process. In addition to eliminating odour problems for pultruder workers, the new technology supports precise temperature management during curing and thus increases production speeds. The systems are highly automated with the aid of sensors. Another advantage of the iPul machines is extensive flexibility and precision. Thanks to the newly designed injection reservoir with mixing head and metering device, a wide variety of resins can be processed, including highly reactive polyurethane systems. In addition, matrix material is sprayed at low pressure to reduce costs. Wolfgang Hinz from KraussMaffei (left) and Benedikt Kilian from Covestro (second from left) received the 2017 FSK Innovation Award for polyurethanes. FSK CEO Albrecht Manderscheid (CANNON Germany) and Dr. Alexander Strietholt (Dow Germany), former spokesperson of the polyurethanes expert group at FSK, shared in this honour.

The Polyurethane Advantage

Polyurethane resins offer significant advantages over pultrusion materials such as epoxy, unsaturated polyester and vinyl ester resins. Low viscosity, good fibre wetting and high reactivity support faster processing speeds than epoxies, which reduces production costs. Another advantage is considerable flexibility; the reaction time and viscosity of polyurethane resins can vary widely, allowing the replication of very fine component geometries. Covestro markets Baydur® PUL and Desmocomp® polyurethane systems for pultrusion. Baydur® PUL are liquid, two-component systems for the manufacture of high-strength components with superior thermal insulation properties. They are therefore highly suitable for use in insulating window frames. Desmocomp® offers not only good mechanical properties but also excellent UV and weather resistance, making it the preferred product for outdoor applications. The aliphatic system won a JEC Innovation Award at this year's JEC World Composites Fair.

How Pultrusion Works

In pultrusion, glass, carbon or other fibres are continuously fed from spools through an injection chamber where they are impregnated with a liquid thermoset resin system. The fibre is cured by heating in a composite mould. The hardened component is continuously pulled through this process, which is why it is called pultrusion. After the profile is cooled, it is cut with an integrated saw. The resulting straight components offer low weight matched with very high strength and stiffness in the fibre direction. Covestro and the Plastics Processing Institute (IKV) at RWTH Aachen University work in close collaboration on the development of the pultrusion process using polyurethane. With its long-standing experience in polyurethane processing and reactive resin systems as well as in pultrusion, the IKV supports Covestro in addressing development issues related to pultrusion processes. The FSK has sponsored the Innovation Award annually since 1998 to recognise exceptional ideas, products and processes in the categories of Design, Technology and Process and Chemical Engineering.