Waste textiles work against fire

Materials World magazine
8 May 2011

A consortium of UK companies says it has developed a method for producing flame-retardant (FR) products that use only recycled textiles and sustainable FR components. This could promise a cheaper method of producing FR products and cut the amount of textile waste going to landfill.

The project is led by the UK’s Furniture Industry Research Association (FIRA) and titled Reduced Emissions by Development of Novel Sustainable Flame Retardant Products (REDFR). It was spurred by the growing scarcity of recycled wool-rich clothing, the traditional fire-retardant material used in upholstery and mattresses.

The availability of wool-rich garments is reducing and the cost increasing, as consumers tend to choose fleeces and interlined jackets constructed from synthetic fibre rather than woollen jumpers and coats, according to the consortium. Synthetic FR products are available, but many of these have associated health concerns including bioaccumulation and carcinogenity, and are harmful to the environment. The use of many previously commonplace FRs is now banned or restricted following health studies.

The consortium therefore set about developing a FR system for nonwoven fabrics (such as felt) with minimal environmental impact and no health and safety concerns.

It says that although the manufacturing process is confidential, it is compatible with a wide range of fibre types and has analysed the fibre composition of nearly 35,000 ‘postconsumer’ garments (through project partner Aestiva Ltd, Kettering, UK,) in order to ensure effectiveness.

The FR system has undergone a full life-cycle assessment by member GnoSys UK, in Surrey. The study showed the REDFR solution to have a massively lower environmental impact than using virgin wool and a markedly lower impact than a conventional FR treatment in seven of the ten categories considered.

These include abiotic depletion, acidification, global warming potential, ozone layer depletion, human toxicity, terrestial ecotoxicity and photochemical oxidation. The system is also said to have achieved a 100% pass rate for all the pertinent flammability tests demanded by the UK’s furniture safety standards, while minimising the amount of treatment required – to a claimed one-tenth of traditional dosing levels.

Concept-proving samples of a FR nonwoven pad have been manufactured on a pilot scale by consortium member the Nonwovens Innovation & Research Institute (NIRI), with consequent full-scale trials at nonwoven pad manufacturer and project partner Edward Clay & Son, both based in West Yorkshire, UK.

Dr. Andrew Hewitt of NIRI explains, ‘The technology is already cost-competetive and we expect REDFR to become less expensive than existing production methods as the price of wool-rich recycled clothing continues to rise. We focused on developing a technology that is fully compatible with existing production methods, so it can be readily incorporated into existing manufacturing plants [with] minimum inconvenience and cost.’

While the largest markets for the technology are in the furniture, automotive and transport industries, Hewitt adds that other markets such as insulation are also being considered.

The REDFR consortium is now looking to license the technology to commercial partners.