The conference not only focused on the transfer of knowledge by experts, but also wanted to encourage the participants to exchange their views on the subject of "textile microplastics". In the afternoon, the participants therefore discussed in three groups, among other things, the potential of biodegradable raw materials, technological challenges for textile manufacturers, opportunities and limits of improving wastewater treatment technology and the role of consumers. Here's a summary of the main theses and assessments:
Working Group I: Alternative fibres and sustainability - problems and research approaches
Christian Lott, Managing Director of Hydra Marine Sciences GmbH, presented key research results on the degradability of biodegradable plastics in marine environments. The key question was: Under what conditions do microorganisms completely convert the polymer into CO2/methane, H2O and biomass?
The findings give - with some reservations - hope that an increasing use of alternative fibre materials could reduce the negative consequences of textile microplastics for the environment:
- All tested materials that are biodegradable in laboratory tests showed disintegration in field tests.
- Different materials are degraded differently under different conditions, e.g. oxygen availability.
- Degradability and its rate depend on climate zone and habitat conditions such as matrix (water, sand, mud), temperature and nutrients.
The presentation of Christian Lott can be found here.
Subsequently, the participants discussed further questions concerning biodegradable raw materials and gave advice for experiments with alternative fibre materials:
- What is important in the selection of biodegradable yarns?
A methodologically clean procedure should be defined in advance and the use of selected test methods and verification by certificates, DIN or ISO standards should be planned. In addition, the use of so-called oxo-degradable plastics should be avoided at all costs. Background: There are indications that these plastics are not biodegradable, but only disintegrate into very small pieces.
- What are other criteria in the search for alternative fibre materials?
An important criteria is the compatibility of sustainability and the market. Suitable fibres must be able to withstand the conflicting demands of "functionality vs. textile requirement vs. sustainability". A further condition is that the availability of the underlying raw material and the means used as well as price stability are guaranteed. When considering and evaluating the fibres, the approaches and test methods must be comparable.
- What needs to be considered when developing low-emission textiles?
The fibres finally selected for the project should first be considered and investigated in their unprocessed pure form and then in treated form. When considering alternative fibre materials, a holistic approach plays a decisive role. In addition, all individual process steps in the manufacture of textiles should be examined and looked at (example here is the HIGG index).
Working Group II: Filtering out microplastics and material changeover - potentials and limits of the currently discussed solutions
- What are the chances and limits of optimizing wastewater treatment plant technology?
Opinion of the panel: For Germany and comparable countries this is a path that should be followed. However, this approach will probably not solve the global microplastic problem in the foreseeable future - the corresponding infrastructure is too underdeveloped, particularly in countries in East Asia, where most textiles are produced and where most plastic waste is generated worldwide.
- What should the textile industry change?
Some suggestions / opinions of the participants: The processes in the production countries in East Asia can probably only be converted to alternative fibres in small steps; cellulose as a basic material is well suited and should be used more often; warnings against competition with food production caused by the cultivation of biobased raw materials are exaggerated - by tackling other factors such as food waste or the cultivation of animal feed, sufficient arable land can be made available; the recyclability of textiles should be increased.
- What are alternative solutions?
Installing microplastic filters in household washing machines sounds promising, but is technically demanding and forces end-users to dispose of the microplastic regularly (the TextileMission partners will nevertheless test such a possibility); industrial washing machines at the production site, which wash out most of the microplastic at the beginning of the product life cycle, seem easier to implement so far.
Working Group III: Sustainable and biodegradable clothing from a consumer perspective
- What are customer expectations regarding the functionality of sports and outdoor clothing made of fleece?
Heat retention, fluffiness, breatheability and quick drying are important properties that consumers will hardly accept as a loss in favour of greater sustainability. Compared to polyester, yarn manufacturers still describe it as a major technical challenge to ensure that biodegradable yarns e.g. have roughly the same tensile strength and dyeability as biodegradable yarns.
- Which textiles with reduced emission risk are already on the market?
The loss of textile fibres (especially in fleece articles) has so far hardly allowed you to reduce your emissions. Alternative solutions have so far been based on the use of natural fibres such as Lyocell, which are biodegradable. Examples are fleece fabrics made of biodegradable roughened inner side, whose emission potential is estimated to be particularly high, and polyester outer side. Such solutions are at least a step in the right direction for the participants; the outdoor specialist VAUDE and TextileMission-Partner presented an example for the use of Tencel with its new BIOPILE fleece.
- What role does the microplastic problem play in customers' purchasing decisions?
Although awareness is growing slowly, the mass of consumers will buy by price in the foreseeable future, and less sustainable products often have an advantage here. The Guppyfried wash bags of the Stop! Microwaste initiative, among others, contribute to a higher awareness on the part of consumers. In addition, if demand for sustainable products rises noticeably, the price will soon fall.
- What potential does the expansion of textile recycling offer for the reduction of microplastics?
Some participants were sceptical. Recycled polyester textiles are suspected of causing even higher microplastic emissions, as their quality is lower. Others pointed out that increased recycling would at least result in significantly less fibre material being newly produced. This would significantly reduce the output of microplastic in the production of fabrics, i.e. where it seems to be highest according to previous assumptions.
Some of the conference contents had also been tangible. TextileMission project partner VAUDE exhibited parts of its sustainably produced collection in the foyer. A sample of the Tencel fleece mentioned in the text can be seen in the photo above left.