Textile fibre from paper-grade pulp

STARTING DATE: October 01, 2018

The aim of this project is to develop and demonstrate the feasibility of a new concept, in which paper-grade pulp is converted into a novel Kuura® textile fibres (i.e., a lyocell-type staple fibre). The pulp in question is today already made by Metsä Group utilising Nordic spruce and pine as the raw materials. An essential part of our concept is locating the textile fibre production unit next to the unit producing the pulp. In other words, integrating the Kuura® production to one of Metsä Group’s modern, highly-efficient bioproduct mills. The aim of the project is to meet the growing demand for more sustainable textile fibres by introducing to the market an alternative to cotton and other cellulosic textile fibres (latter also known as ‘man-made cellulosic fibres’). The Kuura® fibre does not result in microplastics problems. The fibre is recyclable on par with other man-made cellulosic fibres, and Metsä Group can trace back the cellulosic material all the way to the local forests.

At the heart of this on-going Kuura® development project is a semi-industrial production plant (a demo plant) located in Äänekoski, Finland. The demo plant is in practise built as part of Metsä Group’s bioproduct mill in Äänekoski. The demo plant was started up in the end of 2020 and it has a nameplate capacity of approximately a tonne per day. Based on the outcome of the on-going demonstration project, Metsä Group will assess investing in a commercial factory and thus starting its textile fibre business.

Promising sustainability results for Metsä Group’s Kuura® textile fibre

In 2024, a new Life Cycle Assessment (LCA) of the Kuura® textile fibre was conducted. The assessment, based on a hypothetical industrial-scale plant of 100,000 tonnes of Kuura® fibre per year, was carried out by an external expert organisation, Etteplan, who applied the well-known, ISO standardised methodology for the assignment.

The outcome of the assessment is very promising (Figure 1). For example, when comparing to commercial man-made cellulosic fibres (viscose and lyocell), and to cotton fibre, large-scale production of Kuura® fibre, applying the Metsä Group concept, would result in clearly lower level of greenhouse gas emissions (in the methodology known as “global warming potential”). This outcome supports well our goal of developing a competitive alternative to the textile fibre market.

Figure 1. The relative cradle-to-mill gate global warming potential (fossil, kg CO₂ eq.) for one tonne of cellulosic staple fibres. (Cotton: fibre production, Ecoinvent 3.10; Viscose, Austria: European beech, integrated production, biomass & recovered energy from MSWI; Lyocell, Austria: eucalyptus and beech, separate pulp production, energy 70% gas & 30% biomass; Lyocell 2012, Austria: eucalyptus and beech, separate pulp production, 100% recovered energy from MSWI). The bars in the figure are normalised in height so that the viscose result represents 100%.

The Kuura® textile fibre would be produced from softwood Kraft pulp (i.e., paper-grade pulp), not from dissolving pulp, which is commonly used as raw material in the production of man-made cellulosic fibres. The wood for the pulp production would, in turn, be procured from forests located close to the pulp and textile fibre mills. A significant share of the forests in question are today owned by owner-members of Metsä Group’s parent company.

The Äänekoski bioproduct mill (i.e., the unit producing the pulp for the demo plant) is a greenfield investment that was started up in 2017. The bioproduct mill operates without any fossil energy and it is one of the most modern pulp-producing mills globally. This setup results in the mill generating significant amounts of renewable energy (steam, electricity, etc.) in excess. This excess, in turn, would be used as the source of energy, when producing the Kuura® textile fibres. Integrating textile fibre production to such an efficient host mill would result in a multitude of environmental benefits, as shown by the LCA exercise.

The LCA was made according to ISO 14040:2006 and ISO 14044:2006 standards for LCA studies and ISO 14067:2018 standard for carbon footprint studies applying a cradle-to-mill gate system boundary. The LCA work and the comparison to alternative fibres were both critically reviewed by a third party (RISE Research Institutes of Sweden). No major cut-offs were included in the assessment. Inventory data of Kuura® production was based on the newest available mass and energy balances for a possible 100,000 tonnes per year commercial mill integrated to Metsä Group’s bioproduct mill in Äänekoski, Finland. The data used to assess the references was collected from well-known scientific sources where cotton fibre production value is from Ecoinvent 3.10 and man-made cellulosic fibres are produced in Austria by different processes.^*)

Additional material: 

250127 Life cycle assessment of Kuura textile fibre 2024_Summary report.pdf

Comparing the environmental performance of Kuura fibre® with the alternative cellulosic fibres v2 December 20 2024.pdf

final critical review statement Metsa Fibre Kuura 08-11-2024.pdf

critical review statement Comparing the environmental performance of Kuura® fibre with the 08-01-2025.pdf

^*)Shen, L.; Patel, M.K. Life Cycle Assessment of man-made cellulose fibres (2010) Lenzinger Berichte, volume 88, pp. 1 - 59