Technologies

The lyocell production process is the most modern method for producing fibers from wood. It has been successfully applied on an industrial scale for about 25 years and is particularly environmentally responsible – an alternative to the complex viscose and modal production process. The underlying idea of the lyocell process is to dissolve and process the pulp in a closed loop without any chemical derivatisation.

Similar to LENZING™ Viscose and LENZING™ Modal fibers, the basic raw material is dissolving wood pulp from sustainable forestry. In contrast to the viscose process an organic solvent called N-methylmorpholine-N-oxide (NMMO) is used to directly dissolve the pulp without any chemical change. For this reason, it is considerably simpler than viscose production. The technology developed by Lenzing enables more than 99 percent of the solvent to be recovered in a closed chemical loop and then fed back into the production process.Moreover, Lenzing has constantly refined the lyocell production process over the years, and steadily reduced energy consumption on the basis of continuous optimization.

In a first step, the cellulose in the pulp is converted and matured. Then in the sulfidation process step, which is the core process of the viscoseprocess a spinning solution is produced. This honey-like, viscous mass is further refined in various physical process steps to increase quality before it is pressed through fine nozzles into the spinning bath. Here, the cellulose originally used is completely regenerated under precisely defined process conditions, resulting in fibers with predetermined properties and quality characteristics. In the further course of the process, the fibers are cut, subjected to a washing process and dried.

All LENZING™ fibers are finished with a finish of soap-like substances, the so-called avivage, for better processing.

In addition to maintaining high and consistent quality standards for the more than 500 different fiber types, the special feature of the viscose process developed by Lenzing is that technical solutions are consistently developed and applied in order to continuously raise environmental standards

Lenzing is regarded as a global leader in environmental standards due to the high recovery rates of chemicals, the use of renewable energy sources, the extensive use of waste heat and the treatment and purification of waste water.

A process-related by-product of fiber production by the viscose process is sodium sulphate. Sodium suphate is separated from the fiber production process in separate process steps and converted to high-purity product quality. This valuable by-product can thus be used in the detergent industry, the glass industry and also in the food industry.

LENZING™ Modal fibers are produced in a process that is basically comparable to the viscose process. However, by specific modification of relevant process settings in the production of the spinning solution as well as in the spinning process, it is possible to produce fibers which are mainly characterized by their high wet modulus. A high fiber strength is necessary to achieve the dimensional stability of the textiles on the one hand and the production of very fine yarns on the other hand. Very fine yarns are processed, e.g. for high-quality lingerie, they feel naturally soft  and smooth to the touch. Lenzing has succeeded in optimizing the process in such a way that these fibers can be produced with outstanding properties and high uniformity.

Wood is far too valuable to only use it for extracting pulp to produce fibers. We respect the assets of every tree: Use all, spoil none — we make the best use of this natural resource and turn it into as many valuable products as possible. This concept is called the biorefinery.

At our biorefineries in Lenzing, Paskov and Indianópolis, we use the renewable source material wood as universal replacement for non-renewable raw materials that are faced with increasing criticism, such as crude oil. Therefore, we aim to utilize and commercialize all of the wood’s natural components by turning them into pulp for Lenzing fibers or other useful Lenzing solutions for various industries.

Our biorefinery products, for example, are valuable supplies to the food industry: acetic acid acts as the perfect ingredient to pickle vegetables, and xylose is processed into a low-calorie sugar substitute. 

After our renewable raw material wood has provided us with valuable products, it still is precious to us: The energy contained in the wood is used to operate our facilities, making them almost fully energy self-sufficient.

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Area of application: Textile

Fiber type: Fibers with recycling content in combination with TENCEL™ or LENZING™ ECOVERO™ brand

Each year about over 100 million tons of fibers are consumed to produce textile and nonwovens products. For example, 140 billion garments are manufactured from these fibers. But what should be done with them when they are no longer needed? The REFIBRA™ technology represents one first credible response to this challenge.

However, in addition to wood pulp, up to one-third of the raw materials are comprised of pulp from cutting waste generated by the production of cotton garments, and now, for the first time, also post-consumer cotton textile waste. By 2025, we want to set an even higher standard for the industry and offer viscose, modal and lyocell staple fibers with up to 50 percent post-consumer recycled content on a commercial scale.

In this way we have demonstrated a practical solution for promoting textile recycling processes. Numerous fashion brands are already working on fashion collections featuring Lenzing fibers manufactured on the basis of the REFIBRA™ technology.

Area of application: Textile

Fiber type: LENZING™ Lyocell Filament

After several years of development work, Lenzing has succeeded in also adapting its environmentally responsible lyocell production technology to continuous special yarns directly made from filaments. The results are high-quality yarns for the luxury fashion segment which Lenzing markets under the brand name TENCEL™ Luxe. In this way we also open up the possibility for haute couture to integrate sustainable fibers in their products. Today TENCEL™ Luxe stands for a combination of sustainability, performance and aesthetics.

Area of application: Nonwovens

The LENZING™ Nonwoven technology is an innovative R&D development technology platform that allows producing a wide range of novel sustainable nonwoven materials from the raw material wood. The patented nonwoven web formation process – Lenzing holds more than 25 patent applications - starts with dissolving wood pulp and produces a directly formed cellulosic nonwoven fabric made of 100 percent continuous lyocell filament. This technology combines fiber and nonwoven production in only one step and sets new standards in the field of cellulose nonwoven fabrics with respect to efficiency, circularity and ecological sustainability.The flexibility of this technology and possible integration with other nonwoven technologies will enable the development of a wider range of new cellulosic materials and composite structures for highly engineered end use applications.

Area of application: Textile

Fiber type: LENZING™ Modal Black/Color, LENZING™ Viscose Color/Black

The environmentally friendly Eco Color technology replaces the resource-intensive conventional dyeing process of finished fabrics or nonwovens. Our Eco Color technology enables us to dye fibers during production, eliminating the need for a processing step at our downstream partners. This leads to considerable savings in water and energy from the source to the finished fabricproduct. This means a lower environmental impact compared to conventionally dyed fabrics and nonwovens fabrics.

Dope-dyed fibers also have the advantage that the color pigments are deeply embedded in the fiber. As a result, they retain a long-lasting color brilliance compared to conventionally dyed fabrics or nonwovens, including black, a popular color for textiles, and are less prone to fading even after repeated washing.

Fibers produced under the Eco Color technology have been certified with the EU Ecolabel, a label of environmental excellence awarded to products meeting high environmental standards throughout their life cycle.