Main content area

Determining the mechanism controlling glass fibre strength loss during thermal recycling of waste composites Part A Applied science and manufacturing

Feih, S., Mouritz, A.P., Case, S.W.
Composites 2015 v.76 pp. 255-261
fiberglass, glass fibers, heat treatment, milling, recycling, temperature, wastes
This paper presents an experimental investigation into the large reductions to the tensile fracture stress and the associated strength loss mechanism of E-glass fibres during thermal recycling. Fractographic analysis reveals the fracture process is controlled by surface flaws, irrespective of heat treatment temperature and duration. The fracture toughness is an important material property in order to understand possible changes in the strength–flaw relationship during heat treatment. Focussed ion beam (FIB) milling is used to artificially create a single nano-sized deep notch (between 30 and 1000nm) in glass fibres. The strength loss, fracture toughness, fracture mirror constant and fracture mechanism observed for nano-notched and thermally recycled fibres are identical, indicating bulk property changes do not occur during thermal recycling. The study proves conclusively that surface flaw growth is the controlling mechanism reducing fibreglass strength during thermal recycling of waste polymer composites.