Manufacturing of miniaturized thermoplastic FRP components using a novel reaction injection pultrusion process
Fiber-reinforced polymers (FRP) are used for many applications because of their lightweight, high strength and variability. Besides large structural parts, there is a demand for miniaturized components, mostly used for medical applications. Main reason is the excellent compatibility with advanced imaging methods such as Magnetic resonance imaging (MRI). However, only the use of thermosetting polymers is currently feasible for the pultrusion of miniaturized FRP-components, which have major drawbacks such as their non-formability after curing. Therefore, thermoplastic polymers are required for many applications. However, the processing of thermoplastic polymers by pultrusion is more demanding due to their high melt viscosity. This becomes even more challenging the smaller the dimensions. Fraunhofer IPT has developed a miniaturized reactive pultrusion process to manufacture profiles with diameters of 1 mm and below using thermoplastic matrix materials. In this process, monomers with a very low viscosity are used for improved fiber impregnation, which then polymerize directly in the tool form. Using this method, a reliable and cost-efficient manufacturing of miniaturized profiles with excellent properties can be achieved. In this paper, the developed process is described and compared with alternative methods. Experimental test results are presented to show the feasibility of the developed process and the potential for industrial applications.