Wet Fiber Placement: A novel manufacturing technology for continuous fiber reinforced polymer composites

Abstract

The novel Wet Fiber Placement process enables in-line resin impregnation of fiber rovings and direct placement with defined length, position, and orientation. Therefore, the main challenge is the conveying of the impregnated roving, which is limp and provides little friction. For this, a special arrangement of rollers exploiting belt friction is used. In this study, a prototype system is presented and used to give a first impression on the potential of the approach. Therefore, a 24 k carbon fiber roving, saturated with oil, is conveyed at different speeds while varying the winding scheme, the pre-tension, and the test time in order to investigate their influence on the force development, roving slip and fiber/matrix–volume ratio. It could be proven that even at speeds of 15 m/min and at pre-tensions of 60 N in-line impregnation as well as conveying is securely possible, with the slip being below 3%. Therefore, the number of windings and the winding scheme have the greatest influence, whereas pre-tension and conveying velocity have few/no influence on the process results. With an optimized arrangement, a fiber/matrix–volume ratio around 55% is possible.