Ductile viscose fibres and stiff basalt fibres for composite applications. An overview and the potential of hybridisation

In the present study, the hybridisation of ductile viscose (Danufil) and stiff basalt fibres was investigated. The aim was to combine the positive properties of both fibre types in an epoxy matrix. Composites (round rods) were produced with a fibre volume fraction of 40% with a pultrusion technique from Danufil, basalt and a mixture of Danufil and basalt fibres. The hybrid composites were produced on the one hand with a unidirectional (UD) Danufil core and a UD basalt outer layer and vice versa. On the other hand, a UD core layer of Danufil is covered with a twisted basalt outer layer and vice versa. The results have shown that the most successful hybridisation was realised with the UD composite having a Danufil core and a UD basalt outer layer. An impact strength on the level of the basalt fibre-reinforced composite could be achieved whereby the lightweight construction potential could be improved. The spontaneous failure of the basalt fibre-reinforced composite under bending load could be considerably delayed by the addition of Danufil, whereby the strength, stiffness and temperature resistance were significantly improved by the presence of basalt. For the application of round rods, e.g. in poles for mobile architecture, the load-bearing capacity and the safety aspects could be significantly improved by hybridisation.