Carpet recycling: A review of recycled carpets for structural composites

• 400,000 tonnes of carpet waste are sent for disposal to UK landfill sites annually.
• Different end-of-use options for carpet waste in the UK are discussed.
• A tonne of recycled carpet waste saves 4.2 tonnes of CO2 emissions.
• Carpet based composites are potentially suitable for structural applications.

Carpets are multilayer mixtures of different polymers and inorganic fillers that are difficult and costly to reprocess upon disposal. About 400 000 tonnes of carpets are sent to landfill in the UK annually, however, the landfill option is becoming increasingly impractical due to increasing landfill costs and the physical limitations on the number of landfill sites available in the UK. In addition, carpets are non-biodegradable and reduce the availability of landfill for other uses. Hence, this leads to a major drive to increase carpet recycling, which could potentially have a significant positive impact on the environment. This paper gives an overview of the composition of carpets, and the different classifications of carpet waste. In addition, the paper discusses the different end of use options for carpets in the UK. The paper also reviews the different manufacturing processes that utilise carpet waste as raw material in the fabrication of structural composites. The tensile and flexural properties of these composites are presented and discussed. These mechanical properties appear to support the use of carpet waste as potential composite materials for structural load-bearing applications.