A scale-up of processing non-woven flax/PLA tape and triaxial glass fibre fabric for composites

In the drive towards a sustainable bio-economy, a growing interest in the development of composite materials using renewable raw material resources such as flax fibre reinforced polylactic acid (PLA), known as a flax-tape composite (FTC), has been observed. Flax/PLA is one of the cornerstones for the sustainable economic growth of natural fibre composites, while the use of hydrocarbon fossil resources and synthetic fibres such as glass and carbon have caused severe environmental impacts along their entire life cycles. In this study, the manufacturing process for the production of flax tape and triaxial glass fibre were evaluated through life cycle assessment (LCA) gate-to-gate, based on an input-output model, to estimate the energy demand and environmental impacts. The quality of the natural hybrid composite produced and cost-effectiveness of their LCA were dependent on their roving processing speeds; temperature applied to the flax tape and triaxial glass fabrics during processing. This was optimised to be 4 m/min at a temperature of 170 oC. In contrast, normal triaxial glass fibre production took a slower speed of 1 m/min using a roving glass fibre laminating machine. The results showed that when the flax and PLA were commingled to produce a new composite material in the form of a flax tape, the energy consumption was 0.25 MJ/kg, lower than 0.8 MJ/kg of glass fibre fabric composites. Flax tape and glass fibre fabric composites have a carbon footprint equivalent to 0.036 kg CO2 and 0.11kg CO2, respectively, under the same manufacturing conditions. These are within the technical requirements in the composites industry. The manufacturing process adopted to transform flax/PLA into a similar tape composite was considerably quicker than that of woven glass fibre composite tape. Importantly, this work explored a relationship between the blending process and energy consumption of the flax tape composite in comparison to glass fibre composite, using a standard LCA analytical methodology. The outcomes support an alternative option for replacement of some conventional composite materials and technique for the automotive industry