Injection and infusion technologies

Resin injection processes are used in a variety of very different applications for the production of fibre-reinforced plastics and increasingly take over the place of manual production methods. The resin transfer moulding (RTM) process has gained a special importance due to its usage in automotive industry for serial production of endless fibre reinforced plastics. Besides the economical and material specific advantages, the RTM process delivers better surface quality, improved reproducibility and as well the possibility of relatively easier integration of foam cores and inserts.

Resin infusion methods are particularly suitable for large-scale components, since only a half-shaping tool is needed and thus investment costs can be saved. As a consequence, resin flow pressure is less compared to injection processes since the maximum infusion pressure can be only equal to the environmental pressure. Due to this limitation the use of supporting materials such as fleeces, membranes or special textiles is common. Furthermore, the infusion process can be supported by tailored laminate architectures, flow channels inside the part or intelligent placement of vacuum points. 

In the field of injection processes the department of Polymer Engineering focuses for example on the development of fast curing epoxy systems for RTM processes. Additionally to the particular curing kinetics that have to allow a low viscosity during the injection step and subsequently provide a very fast curing, tailored properties like a high glass transition temperature and improved fracture toughness are core criteria of the developments. Besides, also improving the flame retardancy of fast curing RTM-resins is subject of current work.

Developments related to infusion processes mainly focus on the application in rotor blades for wind turbines. The resin systems to be used for this purpose have to exhibit sufficiently long pot life and low viscosity to fully infiltrate the reinforcing textiles. At the same time, the cured matrix has to offer an excellent fatigue resistance in order to ensure the reliability under service conditions. In the laboratory for dynamic testing at the Department of Polymer Engineering, the fatigue properties of the matrix polymers and their laminates can be characterized.

 

Contact: M. Sc. Gökhan Bakis
Phone: +49 921 5574-82
Fax: +49 921 5574-73
Email: goekhan.bakis@uni-bayreuth.de