Improving Dispersion of Recycled Discontinuous Carbon Fibres to Increase Fibre Throughput in the HiPerDiF Process

Abstract

In order to increase the material throughput of aligned discontinuous fibre composites using technologies such as HiPerDiF, stability of the carbon fibres in an aqueous solution needs to be achieved. Subsequently, a range of surfactants, typically employed to disperse carbon-based materials, have been assessed to determine the most appropriate for use in this regard. The optimum stability of the discontinuous fibres was observed when using the anionic surfactant, sodium dodecylbenzene sulphonate, which was superior to a range of other non-ionic and anionic surfactants, and single-fibre fragmentation demonstrated that the employment of sodium dodecylbenzene sulphonate did not affect the interfacial adhesion between fibres. Rheometry was used to complement the study, to understand the potential mechanisms of the improved stability of discontinuous fibres in aqueous suspension, and it led to the understanding that the increased viscosity was a significant factor. For the shear rates employed, fibre deformation was neither expected nor observed.

Life Cycle Assessment of the High Performance Discontinuous Fibre (HiPerDiF) Technology and Its Operation in Various Countries

“…The focus of this study is on the previous laboratory-scale machine (HiPerDiF 2G), built as a proof of concept for research and development purposes, shown schematically in Figure 1. At the start of the process, discontinuous fibres of between 1 and 15 mm in length are suspended in a low viscosity aqueous carrier fluid [46]. With the aid of the peristaltic pump, this suspension is accelerated and directed through a series of nozzles towards a course of narrowly spaced parallel plates, demonstrated in Figure 1a.…”

Investigating the mechanical failure mechanisms of a novel CFRP composite to inform computational models

“…In efforts to improve the closed loop recyclability of CFRPs, emerging technologies including High Performance Discontinuous Fiber (HiPerDiF) 9 alignment and Tailorable Universal Feedstock and Forming (TuFF) 10 technologies have been developed to produce CFRPs with high mechanical properties utilizing chopped recycled carbon fibers (3 − 6mm), successfully reusing carbon fibers to create structural components. Unfortunately, these techniques make use of thermoset polymers leading to the same recycling challenges of traditional CFRPs.…”

Influence of Different Surfactants on Carbon Fiber Dispersion and the Mechanical Performance of Smart Piezoresistive Cementitious Composites

“…Subsequently, a range of surfactants mentioned in the bibliography, regularly used to disperse materials composed of carbon, have been studied to verify the most suitable for use in this regard. The aqueous solution with the anionic surfactant sodium dodecylbenzene sulphonates is found to be a good dispersion agent for CFs; the interfacial adhesion between fibers is not affected, leading to the optimum stability of the discontinuous fibers [19,[28][29][30]. As an admixture, silica fume (SF) facilitated CFs dispersion and displayed an improvement in the interfacial interaction between the fibers and the Portland cement phases to improve material properties, particularly increasing the strength of cement-based material [3,9,13,27,[29][30][31][32].…”

“…The aqueous solution with the anionic surfactant sodium dodecylbenzene sulphonates is found to be a good dispersion agent for CFs; the interfacial adhesion between fibers is not affected, leading to the optimum stability of the discontinuous fibers [19,[28][29][30]. As an admixture, silica fume (SF) facilitated CFs dispersion and displayed an improvement in the interfacial interaction between the fibers and the Portland cement phases to improve material properties, particularly increasing the strength of cement-based material [3,9,13,27,[29][30][31][32]. A typical silica fume content is 15% by the mass of cement [16,31,[33][34][35][36][37][38][39], with the normal particle size around 0.1 mm helping the fibers break loose from one another as mixing arises [3,40].…”