Fig. 8: Foam core; right: section view of a segment; left: assembled foam core with the resulting bore holes Fig. 9: Pick-up sequence of UD chords with main frame Fig. 6: Module 1 on the lay-up desk The frame for this module is made of aluminium profiles. This frame provides a mount for the fibre material. The fibres are positioned through a guiding funnel and finally applied on a desk by a pressing drum. The module itself is equipped with guiding rollers which move on rails. The rails are attached to the desk. Main frame The main frame (see Figure 7) is made of aluminium profiles as well. A triangular structure was chosen to ensure maximum stiffness. A flange is left open to enable the application and the winding process. Aluminium plates are fitted at both ends to hold the bearings, with a rotation drive at one end. The drive shaft has two bore holes. The tubes that carry the foam core are inserted through the drive shafts and held in place by the main frame. The steel tubes are covered with CFRP tubes in order to enhance their stiffness and reduce the need for additional support. Since foam cores of the required size are not available on the market, the foam core is assembled on the supporting tubes. Figure 8 shows a prepared foam core segment on the right and, on the left, the assembled foam core with the resulting bore holes. Fig. 7: Triangular-shaped main frame The main frame also enables picking up the chord preforms from the preparation desk. For correct positioning, the supporting tubes slide into guiding rails mounted on the preparation desk. Figure 9 shows a schematic view of the handling process. Module 2 In this module, the ±45° layers are applied using a winding process. Carbon fibre rovings up to 50k are used for this purpose. The installation makes it possible to apply up to 62 rovings in parallel. The rovings are aligned using a comb. The main frame is put into a tracking system and connected to a linear guide unit. The tracking system allows ergonomic changes during the preform manufacturing step. Figure 10 shows the general arrangement on the shop floor (top view). The rovings are provided by a fibre creel that makes it possible to adjust the tension of the single fibres up to 350cN. Figure 11 shows the integration of the main frame into module 2. The main frame has fixed rollers for the translational feed motion Fig. 10: Layout of module 2 on the shop floor No92 October - November 2014 / jec composites magazine 53