Mussels in Lenzing Lyocell nets. © Lenzing / E. Grebe

The Lenzing Group, a leader in specialty fibres based on the renewable material wood, has today introduced its botanic solution for marine applications and in particular for aquatic farming, at the Techtextil trade fair in Frankurt. The wood-based Lenzing branded Lyocell fibres are used for the construction of ropes and nets in order to support the cultivation of marine cultures such as molluscs, mussels and edible seaweed to reduce plastic in the sea.

Serious problem for our marine environment

“Annually, about 8 million metric tons of plastics end up in the ocean, resulting in an estimated 165 million tons of plastic debris, currently floating in the marine environment, threatening the health and safety of marine life,” Lenzing told members of the international trade press yesterday in Frankfurt.

 “The loss of conventionally used synthetic fibres and plastics in the ocean accounts for 80 % of all marine pollution. * This is not only dangerous for marine life but also for humans as we consume some of these micro plastics through our food.”

“The development of 100% wood-based mussel nets with Lenzing Lyocell fibres contribute to the reduction of the annual plastic quantity in marine environment,” says Marine Crnoja-Cosic, Head of Application Development New Business Areas.

Lenzing’s Techtextil Press Conference. © Lenzing Group.

Lyocell innovation for the marine industry

The Lenzing Group initiated a project in collaboration with two major partners, Sächsisches Textilforschungsinstitut e.V. (STFI) and FIUM GmbH & Co. KG – Institut für Fisch & Umwelt (FIUM) in order to develop a sustainable solution for the marine industry, which does not compromise mechanical performance.

“There are many different methods of using textile structures as a support for the growth of marine organisms. The important feature of the present invention is that the textile structure is made of wood-based cellulosic fibres. This gives the advantage that any of the textile structure which is released into the environment due to accident, storm damage, negligence or any other cause will degrade in a reasonable time and not leave non- degradable residues,” Lenzing says.

“Up to now, nylon and polypropylene are most commonly used for rope and net materials. Although these materials are durable and have a sufficient strength, they do not have a natural origin and are not marine biodegradable. They stay in the oceans for years. Nets and ropes consisting out of Lyocell fibres proved that they have sufficient strength to carry the weight of the growing cultures without breakage and have the big advantage of biodegradability in the oceans.”

Proven in tests

Sächsisches Textilforschungsinstitut e.V. constructed different prototypes and replicates out of Lyocell fibres in March 2018 and afterwards an initial underwater material test was started in the Baltic Sea. Meanwhile, prototypes were installed at 6 to 10 metre depth at an artificial reef platform in Rostock Nienhagen. The objective of the trial was to prove that marine applications produced from Lyocell fibres can fulfil the key properties of conventional marine supports, which are sufficient strength to carry the weights of the growing cultures without breakage. Additionally, the trial should investigate if Lyocell fibres represent a pleasant environment for particular marine organisms and also prove the marine biodegradability after usage.

Lenzing’s Techtextil booth. © Lenzing Group.

“After four organized dives by our project partner FIUM, first test results were available. All Lyocell fibres represent an appealing growing material for marine organisms. Overall 14 different sea dwellers like blue mussels, crustaceans, echinoderms or snails adhered to the test material. First test results regarding performance and biodegradability were Promising,” Lenzing says.**

Compostability and biodegradeability are key

“Sustainability advantages in aquatic farming are particularly evident, given the fact that the material is being used directly in the oceanic eco system. Lyocell Standard fibres are certified as compostable and biodegradable under industrial, home, soil and also under marine conditions. If pieces of the nets break off, they will harmlessly decompose and have no influence on marine organisms. In order to close the sustainability loop, the nets can be composted after harvesting and processing,” Lenzing explains.

Further developments

“This development brings sustainable solutions to aquatic farming encouraging Lenzing to assess and establish further steps towards commercialization, together with innovative value chain partners”, says Crnoja- Cosic. “Furthermore, future development will focus on optimizing the nets construction for more durable products broadening the scope of 100% Lyocell based marine nets in marine environment,” concludes Ms. Crnoja- Cosic. “.

* Science Advances, Geyer R., Humans have made 8.3 Billion tons of plastic. Where does it all go? https://www.pbs.org/newshour/science/humans-made-8-3-billion-tons-plastic-go Accessed: 2018-09-13

**Patent WO 2018/204 940 “Marine degradable supports”