Lenzing AG, a specialty fiber supplier from Austria, and Södra, a Swedish forest-owner association, have developed OnceMore®, a process that recycles polyester-cotton fiber blends into textile pulp. Södra’s pulp mill in Väröbacka, Sweden, receives pulpwood from sustainably managed forests, mainly spruce and pine, owned by Södra members. The site also hosts Södra Innovation, a research hub for testing new ideas in pulp and sawmills.

The OnceMore® process combines textile waste with wood from responsibly managed forests, offering an alternative to man-made cellulosic fibers like viscose or lyocell, resulting in less pollution. Södra collects polyester-cotton fiber blends from recycling and waste management companies, separates the materials, and revives cotton fibers by combining them with certified wood cellulose. The separated polyester fibers are incinerated to produce energy for the process.

The resulting pulp, certified by the Recycle Claim Standard, consists of 20% recycled textiles, with Södra aiming to increase this to 50%. Currently, only white and off-white materials are processed, but trials are underway to include colored fabrics.

Södra collects textile waste that must be cotton or poly-cotton with at least 70% cotton content. Current partners include Lounais-Suomen Jätehuolto Oy (a Finnish waste management company), Frankenhuis (a Dutch textile recycling company), Rester (a Finnish company that recovers business textiles), the Textile Services Association (a UK organization for commercial laundry and textile rentals), and the Salvation Army.