## 3 Results  
The environmental impacts in each impact category (as classified in Section 2) for the individual product systems (linear, first loop and second loop) are presented relative to each other in Figure 3. The linear jacket has the highest impacts in all categories (grey bars). The \"second loop\" product system (orange in Figure 2)--utilizing virgin PES to replace the losses from the \"first loop\" product system (blue in Figure 2)--always scores lowest in all categories (orange bars). This second loop product system shows even lower impacts compared to the first loop product system, because it requires fewer newly produced raw materials as it utilizes the PES material and the zipper from the previous loop. The biggest impact differences between the linear and circular product system occur in the categories of (1) respiratory inorganics (2) human toxicity and (3) water scarcity. Responsible for the lower impacts of the circular product systems are, respectively: (1) fewer transportation and electricity needs due to lower PES material requirements; (2) less incineration of materials and (3) less virgin material production and water consumption. The major impact differences between the two circular product systems (blue and orange bars) are visible in the categories respiratory inorganics, ecotoxicity freshwater and water scarcity. For respiratory inorganics, this is again due to lower emissions resulting from less transportation (due to fewer materials transported on shorter routes). The ecotoxicity for freshwater is higher for the first loop mostly due to more materials being produced (e.g., the zipper) and thus more mining required. Additionally, in the first loop product system, more materials are incinerated (especially the losses from the PET bottle  
Figure 3: Environmental impact comparison between the linear product system (grey) and the first (blue) and second loop (orange) product systems. recycling). Regarding water scarcity, the impact allocation of the PET bottle production and the higher water demand in the first loop (due to more materials being produced) lead to higher impacts in this category compared to the second loop. Note that due to the input of high quality virgin PES material starting from the second loop, this second loop can now be theoretically repeated for an unlimited number of loops as long as the quality of the recycled PES material is sufficiently high enough for the fiber spin process. As explained in the method section of this study, in a second step the average impacts across several wear2 wearTM loops are calculated. The impacts of these average product systems can be compared to one linear product system. Due to the unique fact that the orange product system (meaning the second loop) can be prolonged significantly as long as the quality of the PES material is sufficiently high, three scenarios are modelled in this study that vary the number of interconnected loops (one blue loop connected to x number of orange loops). In the first scenario, the average impacts of three wear2 wearTM loops (one blue and two orange ones) are compared to the impacts of one linear product system. The second scenario includes five loops (i.e., one blue and four orange ones), the third scenario ten (i.e., one blue and nine orange ones). The results are illustrated in Figure 4. They show that the more subsequent orange product systems are being simulated, the smaller the impacts are of the combined wear2 wearTM product system (containing one blue and a number of orange loops) in comparison to one single linear product system. For an infinite number of orange loops connected to one blue version, the impact differences of the wear2 wearTM to the linear product system would be equal to the impact differences between one linear and one wear2 wearTM jacket from the second (orange) loop. The reason is simple: simulating an infinite amount of loops means that the first product system (blue) has higher impacts than the all following ones (orange).