The US Federal Trade Commission (FTC) has ruled that fibres made from a renewably sourced polyester polymer called PTT have enough different properties to allow them to be classified under a new generic name - triexta.

The fibres, which are used in apparel and carpets, are made from the polytrimethylene terephthalate (PTT) polymer sold under the DuPont Sorona brand.

But the FTC agreed the triexta fibres, while having the general chemical composition of polyester, also have distinctive features related to durability, resilience, softness, and stretch recovery.

These features also make it more suitable than conventional polyester for apparel uses.

The ruling means the name "triexta" may be used as an alternative to the generic name "polyester".

DuPont began production and distribution of Sorona in 2000, and says fabrics made with Sorona combine durability and softness, built-in permanent stain and ultraviolet (UV) ray resistance, and elasticity.

It also notes that Sorona fabrics provide a carbon dioxide reduction of 30%, while the manufacturing process reduces greenhouse gas emissions by 63% compared to conventional nylon made from petroleum.

Apparel manufacturers including Izod, Timberland, Calvin Klein Golf and Spun Bamboo have incorporated fibres from Sorona into their product lines.