Environmental impact assessment of composites containing recycled plastics

The use of recycled plastics eliminates the need for exploration, extraction and transportation of natural gas and oil, thus greatly reducing the environmental impact. Adding fiber reinforced materials is a potential way to increase plastic recovery and apply recycled plastic to high-value applications.

Saravanan Rajendrana's team at the University of Sheffield used life cycle assessment (LCA) methods to assess the environmental impact of fiber-filled recycled plastics.

The team chose fiberglass and flax as reinforcements. The resource depletion potential and global warming potential of recycled plastics filled with fiberglass and flax fibers were assessed and compared with their respective original alternatives. The properties of the recovered and original composites were estimated based on literature and semi-empirical models. The effects on resource depletion and global warming were compared under the same conditions.

The results show that enhanced recycled plastics can significantly reduce resource consumption and global warming in both civilian and infrastructure applications. Using recycled plastics for composite applications has significant environmental advantages over traditional raw plastics. These results demonstrate that the use of recycled plastics in composites has great potential to reduce adverse environmental impacts and is therefore most suitable for civilian and infrastructure applications. The impact of recycled composites on automotive applications is at best the same as that of the original composites, but a slight reduction or change in the raw material of plastic waste may dramatically increase the environmental impact of the original substitutes by several times. Therefore, in automotive applications, it is recommended not to replace original plastic parts with recycled plastic parts, unless significant lightweight is achieved with the same functional performance.

Resource, Conservation and Cycling（Rajendran S, Scelsi L, Hodzic A, et al. Environmental impact assessment of composites containing recycled plastics. Resources, Conservation and Recycling, 2012, 60: 131-139.）