Felting As A New Method For Z-Reinforcement Of Fabric-Layered Composite Materials

A new method of transversal strengthening of a laminated fabric-reinforced composite is proposed. The fabric pack is punched with needles for felting, which partly pull out and damage the warp/weft threads by barbs, pulling some fibers in the direction of thickness (Z-direction). By increasing the density of needle punches per unit area in the felting zone, it is possible to increase the ability of a layered composite to resist transversal tension or shear stresses. In this case, the strength of the composite in the XY plane decreases slightly. By the example of the single-lap joint of composites (plain weave fabric with a thermoplastic binder), it was shown that felting with a punching density of 30 ... 60 cm(-2) about doubles the shear strength in comparison with typical glued samples without felting.