New polyester will benefit from both bio-sourcing and closed loop reclaim
What is claimed as the world's first commercially-produced bio-derived PET fibre will go into commercial production in Japan in April 2012. Teijin Fibers is introducing the material, dubbed EcoCircle PlantFiber, as both a fibre and a textile and expects to sell 30,000 tonnes in the first year, and raise the rate to 70,000 tonnes by the third year of business. It will be the company's core biomaterial for applications ranging from apparel, car seats and interiors to personal hygiene products.
EcoCircle PlantFiber is made roughly 30 per cent from materials derived from biomass such as sugar cane. Conventional PET typically is made by polymerising ethylene glycol with dimethyl terephthalate or telephthalic acid, the EG accounting for roughly 30 per cent. The EG is replaced by the bio-derived material rather than oil-derived, in a similar way to the new Ecological Plastics materials recently unveiled by Toyota and the celebrated PlantBottle material being used by Coca-Cola.
Teijin Fibers gives its new product an extra spin by integrating it with its EcoCircle closed-loop polyester recycling system in which reclaimed polyester garments are taken back chemically to DMT which the company says is at a purity and quality comparable to material derived directly from petroleum – avoiding the quality degradation which it says has been an issue of conventional recycling based on physical processing. Compared to manufacturing raw polyester materials from oil, Teijin says it is possible to reduce both energy consumption and CO2 emission by about 80 per cent.
The EcoCircle system has now been developed into broader reclamation of polyester products – bottles and PET film have been added to the garment fabric on which the system was based – and in 2004 was extended into developmental processes for reclaiming polycarbonate and polylactic acid. The polycarbonate process is said to give a recycling rate of 96 per cent for bisphenol-A, with reductions in impurities, energy consumption and cost compared with the conventional distillation recycling process.
When applied to PLA the technology uses water alone as a reactor and requires no catalysts or other additives. Normally, PLA is produced from L-lactic acid. Teijin says that if the optical isomer, D-lactic acid – a by-product of the recycling process – is mixed in, the physical properties of the polymer deteriorate. The Teijin technology "facilitates the recovery of almost 100 per cent of the L-lactic acid and essentially prevents the production of by-product D-lactic acid." Production of recycled PLA using this technology uses over 33 per cent less energy than production using plant matter, says Teijin.
Teijin says it is also close to commercialising a system for reclaiming notoriously difficult-to-recycle carbon fibres.