Polymer composites with short recycled glass fibres for wind turbine nacelle cover application

Recycled glass fibres recovered from polymer composites with thermal recycling processes such as pyrolysis are known for their brittleness, which have challenged their use in new polymer composite applications. Despite these challenges, fibres recovered with a pyrolysis process have the advantages of being clean with a residue free surface and maintain a high Young’s modulus. In this paper, recycled glass fibres obtained from pyrolysis are used in new polymer composites together with pristine glass fibres to form composite laminates for wind turbine nacelle covers. The objective is to investigate the most optimal layup and determine if the resulting composite would sustain loads like the one experienced by a wind turbine nacelle cover during extreme wind events. To do so, sandwich structure composites with pristine fibres in the outer layer and recycled fibres in the inside are manufactured. Composites are produced to study the effect of different content of recycled glass fibres, the effect of fibre pressing, and the use of an adhesive during manufacturing. The quality of the manufactured plates is characterized using microstructure observations, fibre porosity analysis, and mechanical testing. Analytical and numerical modelling is used to estimate whether the composite can sustain the loads required for nacelle cover side panel applications. The results show that all composites manufactured are of high quality and are able to survive the considered extreme load case.