Biorefinery – pulp production in the Lenzing Group natural fibre made from wood for activewear 100 % organic

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April 20, 2021

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Biorefinery – pulp production in the Lenzing Group natural fibre made from wood for activewear 100 % organic

In recent years, interest in wood-based cellulosic fibers has increased due to their sustainability credentials. When the source of raw material is from sustainable for- estry, as proven by forest certificates, and state-of-the-art production processes are applied, wood-based cellulosic fibers can have a very favorable environmental footprint.

Wood-based cellulosic fibers are produced from the natural poly- mer cellulose. Production starts with wood or other plant-based materials, extracts cellulose pulp from them, and then shapes the polymer into fibers and filaments using different technologies (vis- cose, modal, lyocell). The final fiber product consists of the natural polymer cellulose, with a chemical structure identical to natural fibers (e.g. cotton, wool).
Wood-based cellulosic fibers are biodegradable in and therefore provide an environmental responsible alternative to fossil-based plastic materials in textiles and nonwovens, but also in packaging and other applications.
Dissolving wood pulp is the most important raw material used in producing regenerated cellulose fibers, including Lenzing’s wood- based fibers.
Shaping of cellulose pulp into fibers requires a special quality of pulp, referred to as dissolving wood pulp, which has to meet differ- ent requirements from those for paper pulp. Among other things, dissolving wood pulp must have a higher pure cellulose content of over 90 percent, lower impurity levels, be bleached to a high- er level of brightness and have a more uniform molecular weight distribution.
The Lenzing Group produces more than half of the pulp it requires at its sites in Lenzing (Austria) and Paskov (Czech Republic). Suffi- cient quantities of certified wood are purchased for this purpose. In addition to its own pulp production, Lenzing procures pulp on the global market, mostly within the framework of long-term supply contracts.

A biorefinery is a facility for sustainable processing of biomass into a spectrum of marketable biobased prod- ucts and bioenergy.
Lenzing’s biorefinery process ensures that 100 percent of wood constituents are used to produce dissolving wood pulp for fiber production, biobased products, and bioenergy, thereby maximiz- ing value creation from an economic and environmental perspec- tive.
Dissolving wood pulp production at the Lenzing and Paskov sites is not only self-sufficient in terms of meeting its own energy de- mand; the process actually generates more energy than need- ed. This surplus green energy is used on site, for instance for fi- ber production or for export to the local grid. The production of biorefinery products such as acetic acid, furfural and magnesium- ligonosulphonate helps to increase the total yield from wood as well as creating additional economic and environmental value.
Lenzing’s biorefinery process ensures that 100 percent of wood constituents are used to produce dissolving wood pulp for fiber production, biobased products, and bioenergy, thereby maximizing value creation from an economic and environmental perspective.

The facility in Lenzing is the largest integrated pulp and cellulosic fiber production plant in the world. Integrat- ed dissolving wood pulp and fiber production not only provides exceptional economic benefits, it also offers many environmental advantages and savings compared to non-integrated mills. For instance, there is no need for transportation of pulp because of the short distances in- volved, which itself eliminates the need for energy-inten- sive drying and packaging of pulp.

The Lenzing plant produces dissolving wood pulp required for fiber production on site. Traditionally, wood for pulp production at the Lenzing site consists mainly of beech (Fagus sylvatica). Logs are debarked, chipped and treated in a cooking liquor of magnesium bisulfite. Cellulose is a major component of wood – around 40 percent of the wood substance – and is separated as raw pulp in this process. This pulp is then washed and screened to remove the residual cooking liquor, knots, and impurities. The raw pulp is bleached in a totally chlorine-free (TCF) process and turned into pulp sheets or flakes. The other wood constituents remain within the thin liquor together with other cooking chemicals. Marketable biorefinery products such as acetic acid, furfural, and xylose are obtained in further processing steps. More than half of the wood is transformed into pulp and other biobased products. The cooking chemicals are recovered and recycled from the remaining liquor and the organic components are converted into bioenergy (steam and electricity).

Pulp production at the Lenzing site is self-sufficient in terms of meeting its own energy needs. Surplus energy (steam and elec- tricity) is used on site, for instance for fiber production. Lenzing’s expertise in integrated dissolving wood pulp and fiber production is the basis for future opportunities to become CO2 neutral and to contribute to the greenhouse gas reduction target.

Biorefinery plant
in Paskov, Czech Republic

The raw material base for the facility in Paskov is spruce wood (Picea abies) in form of logs and chips. The dissolving pulp produc- tion process based on magnesium bisulfite is similar to that at the Lenzing site (Austria). The other two major components of wood – lignin and hemicellulose – are dissolved in the liquor. The insoluble remainder is crude unbleached pulp. This pulp is then washed and screened. Further, deeper removal of lignin and hemicellulose is performed by means of alkali extraction and a TCF bleaching pro- cess. After final fine screening, the pulp is dried in sheets, baled, and dispatched. The Paskov site is completely self-sufficient in terms of heat and electricity generation. The plant supplies its sur- plus electricity to the public grid.

Pulp production at the Lenzing site is not only self-sufficient in terms of meeting its own energy needs; it actually produces surplus energy. This surplus energy (steam and electricity) is used on site, for instance for fiber production.
All pulp produced at Lenzing pulp production sites is totally chlorine free

Pulp bleaching in the Lenzing Group
Bleaching is necessary to yield a dissolving pulp quality suitable for wood-based cellulosic fibers, such as viscose, modal, and lyocell. Most dissolving wood pulp producers use elemental chlorine free (ECF) pulp bleaching processes.
Lenzing’s two biorefineries produce pulp without using any chemi- cals containing chlorine, but with oxygen-based substances (total- ly chlorine free – TCF).
Due to the elimination of chlorine, dissolving wood pulp produced in the Lenzing Group not only has less impact on the environment and human health but also ensures the high quality required for fiber production.
The technology at both plants satisfies the Best Available Technol- ogy standards of the European Union.1

In addition to its own pulp production, Lenzing procures pulp on the global market (ECF). Not all fiber types offered by Lenzing can be produced using Lenzing’s own totally chlorine free (TCF) pulp because they require specific pulp qualities.

Lenzing’s product portfolio extends from dissolving wood pulp as a basic raw material to standard fibers and inno- vative specialty fibers as well as energy, biorefinery prod- ucts and co-products.

key benefits

Chlorine free
totally chlorine-free

TENCEL™ Modal fibers with Eco Clean technology are manufactured with a completely chlorine-free bleaching technology.

supply chain transparency

supply chain transparency

TENCEL™ Modal fibers with Eco Clean technology are identifiable throughout the whole textile supply chain, until the final garment. A special identification technology supports the supply chain transparency.


responsible environmental choice


responsible environmental choice

TENCEL™ Modal fibers with Eco Clean technology offer the most environmentally responsible choice within all existing modal fibers, including those with Micro technology. Chlorine-free bleaching in pulp and fiber delivers the cleanest modal production technology currently existing.


Austrian origin
Austrian origin

TENCEL™ Modal fibers with Eco Clean technology are produced exclusively in Austria, mainly from beech wood sourced from sustainably managed forests in Central and Eastern Europe. They are manufactured with a totally chlorine-free bleaching technology for both pulp and fibers, in an integrated production site with high environmental standards.

comfortable next to skin (TENCEL™ Modal Micro fibers)

comfortable next to skin (TENCEL™ Modal Micro fibers)

Both dry and moist fabrics made of TENCEL™ Modal fibers with Micro technology were perceived as more pleasant in frictional strain tests on human skin than cotton and polyester fabrics. Furthermore, fabrics made of TENCEL™ Modal fibers displayed a far lower frictional coecient under humid conditions.* This makes TENCEL™ Modal most recommendable for textiles worn next to the skin.

Applicable to Micro technology only

(*Hohenstein testing. Test Report No.18.8.6.0005/Rev1)

fine softness for comfort (TENCEL™ Modal Micro fibers)


fine softness for comfort (TENCEL™ Modal Micro fibers)

For a pleasant fabric perception on the human skin, softness is one of the determining parameters. The ner the cellulosic fibers used in textiles, the softer they will be. TENCEL™ Modal fibers are known for their softness. TENCEL™ Modal fibers with Micro technology are very ne cellulosic bers, supporting enhanced comfort by further contributing to the softness of
textile products.

Applicable to Micro technology only

superb lightness (TENCEL™ Modal Micro fibers)
superb lightness (TENCEL™ Modal Micro fibers)

Lenzing´s fine TENCEL™ Modal fibers with Micro technology can result in very fine yarns, which are processed into very light knitted and woven fabrics.

Applicable to Micro technology only

Micro technology (TENCEL™ Modal Micro fibers)
Micro technology (TENCEL™ Modal Micro fibers)

Among Lenzing’s Lyocell and Modal fiber portfolio, Micro technology offers an even finer quality of lightness and exquisite softness, producing lightweight fabrics, based on their fine titer. Using Micro technology, TENCEL™ Lyocell and Modal fibers are extra fine and light cellulose fibers from sustainable wood sources. TENCEL™ Lyocell and Modal fibers pioneer a new dimension of exquisite softness and lightness, offering long-lasting natural comfort. Fabrics containing TENCEL™ Lyocell and Modal fibers offer efficient moisture absorption to ensure natural skin comfort.

sustainable production (TENCEL™ Modal fibers)
sustainable production (TENCEL™ Modal fibers)

TENCEL™ Lyocell fibers have gained the reputation for their environmentally responsible, closed loop production process, which transforms wood pulp
into cellulosic fibers with high resource efficiency and low ecological impact. This solvent-spinning process recycles process water and reuses the solvent at a recovery rate of more than 99%. This economically viable manufacturing process received the European Award for the Environment from the European Commission in the category “The Technology Award for Sustainable Development”. TENCEL™ Lyocell fibers have been certified as Bio-based by the U.S. Department of Agriculture (USDA). Moreover, all Lenzing fiber production sites operate according to a certified Environmental Management and Occupational Health and Safety system (ISO14001, OHSAS 18001).

Fully integrated pulp and fiber production at the Lenzing site in Austria makes it possible to produce fibers in an eco-responsible way. At Lenzing, we strive to safeguard resources for future generations by the use of renewable energy from the pulp mill and by recovery of remaining components as co-products. Numerous Lenzing innovations have been integrated in the production of TENCEL™ Modal fibers, to make the process environmentally sound.

sustainable production
sustainable production

Fully integrated pulp and fiber production at the Lenzing site in Austria makes it possible to produce fibers in an eco-responsible way. At Lenzing, we strive to safeguard resources for future generations by the use of renewable energy from the pulp mill and by recovery of remaining components as co-products. Numerous Lenzing innovations have been integrated in the production of TENCEL™ Modal fibers, to make the process environmentally sound.

long-lasting softness
long-lasting softness

Exquisite softness derives from fine fibers, creating softer textiles. TENCEL™ Modal fibers exhibit a smooth surface and high ­exibility, resulting in a naturally soft quality of the textile.

The softness of TENCEL™ Modal fibers is confirmed by a variety of physical test methods, including Kawabata, TSA, Handle-o-meter, and Phabro-meter:

- Measurements and hand evaluations of softness show that TENCEL™ Modal fibers are twice as soft as cotton.

- The softness of TENCEL™ Modal fibers lasts longer and is able to withstand repeated wash and dry cycles compared to cotton.

- LENZING™ Modal Micro Air is Lenzing’s finest and lightest wood-based fiber.

- The degrees of softness of LENZING™ Modal, Modal Micro and Modal Micro Air can be measured by various handfeel assessment as well as physical test methods such as the Tissue Softness Analyzer, Phabro-meter and Ring pull-through.

carbon zero
carbon zero

TENCEL™ Modal bers with Eco Clean technology are certified as CarbonNeutral® products by Natural Capital Partners.

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