## 4 Discussion
First, the lifetime assumption of four years has been made based on similar garments produced by the fabric manufacturer, because the wear2 wearTM jacket is not on the market for such a long period of time. Varying this lifetime can have significant impacts on the LCA of a textile product. Secondly, the assumed number of product loops utilizing the same PES again is based on expert judgement and early stage experiments conducted by the partner companies. Varying this assumption can influence the results of the LCA, especially when the quality of the PES material decreases quickly due to possible risks such as the contamination of the recycling processes with impurities. When reflecting the results of the study in a broader system perspective, other sustainability-related challenges emerge. [PERSON] and [PERSON] [15] highlighted the so-called \"circular economy rebound\" describing the phenomena when CE activities--representing lower per-unit-production impacts--nevertheless increase the overall production of materials (e.g., of the company), and thus circumvent the impact reduction potential of CE activities from an industry perspective. Such rebound effects can be caused by several factors. For example, if the price of a product decreases compared to the average market price because it utilizes secondary materials, the result is most likely that costumers will demand more due to the primary law of economics: when prices go down, demand goes up (and vice versa). However, promising design approaches have been developed to cope with such phenomena [32; 33]. Although the production system designed by the wear2 wearTM consortium has the concept of CE at its heart, the impacts of the current wear2 wearTM jacket can be further reduced. For example, all the auxiliary products could be dismantled and reused before the fabric is recycled. Furthermore, advancing other CE strategies, such as reducing the carbon intensity of the energy supply along the entire supply chain, would bring further environmental improvements along the entire wear2 wearTM product system. Despite this improvement potential, several challenges exist for the Design-2-Recycle approach to further reduce the impacts of textiles in general. First, there will be always material losses along the supply chain. As [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [8] (p. 7) put it: \"... many different mechanisms, such as dispersion, dilution, contamination, degradation and process losses, inevitably transform materials into a state of high entropy, where it is essentially lost for technical use and thus material cycles cannot be fully closed\". Second, the recycling process has its limitations, especially when it comes to textiles that are made of mixed fibers. No technologies are yet able to deal with such material mixes efficiently. However, during the last decade various recycling techniques have evolved for textile products, fibers and materials, such as mechanical recycling, different types of chemical and enzymatic recycling processes and combinations of it [34]. This development might bring new technologies in the future, which are able to recycle even textiles composed of different materials. Third, the accumulation of hazardous substances can hinder the recycling processes. As some types of textiles have to fulfil high requirements for functionality, hazardous chemicals might be still necessary. Therefore, it becomes increasingly relevant to substitute such hazardous substances in future or to design \"clean cycles\" and safe \"final sinks\" that systematically remove and dispose such substances before, during and after recycling [35]. Lastly, logistics should be monitored closely with the aim of keeping the transportation impacts low. CE product systems can require more transportation due to additional activities along the supply chain compared to the linear product system, such as the collection and recycling of discarded products [15].