#Footwear#Circular economy

Salomon : the Index.01 Running Trainer

18 .10.2021

"The mere fact of having simplified footwear design, has enabled its impact on climate change to be reduced by 24% compared to standard footwear. " 

"The mere fact of having simplified footwear design, has enabled its impact on climate change to be reduced by 24% compared to standard footwear. " 

How did you get the idea of producing footwear made from recycled and recyclable polyester?

Footwear is the largest business within Salomon today. As we wanted to improve our efforts on the end of service life of our products, its in the footwear sector that we needed to work. When we started to analyse this in order to find solutions, we were initially shocked by how many different materials were found in sport shoes. There’s at least 6 different categories of materials. Rubber for ground contact, EVA (ethylene vinyl acetate) foam for comfort and for the shoe upper, polyamides, polyester, TPU (thermoplastic polyurethane), PU (polyurethane), various foams etc. Of course, the ideal would have been to manufacture a sport’s shoe from a single material. But it is of course, complicated to find a single material capable of fulfilling all functionalities (comfort, grip, etc.) required for footwear. We said to ourselves that we were going to develop footwear made from polyester and TPU, two materials that can be recycled, source them and assemble them in such way that they can be easily separated in order to recover them when the product has reached its end of service life.

Why are polyester and TPU (thermoplastic polyurethane) interesting materials?

The two can be recycled. Our recycled polyester comes from plastic bottles. As for TPU, this is a plastic that can be heated like plasticine to reuse it. For example, we are going to use it for manufacturing ski boots. This will allow us to reduce our consumption in virgin raw materials.


Can you briefly describe your process?

TPU is sold in the form of granules intended to be introduced into raw materials by suppliers. We introduce them to manufacture comfort-providing soles for and soles with gripping properties. Our subcontractors produce a fine film or filament from these granules. The film can be “directly” used but the filament still needs to undergo several operations. They are them assembled and twisted to make yarn that will be sent to a company who will make it into textile. It’s at this moment that we, Salomon, buy it. As regards polyester, it follows the same pathway as TPU textile (granules, filament extrusion, assembly, twisting, weaving or kitting). We use virgin raw polyester, produced from oil by a chemical company, and recycled polyester produced by a plastic bottle recycler. We are working on the proportion of these two categories of materials according to the desired mechanical properties and costing objectives. If certain polyester granules are occasionally produced in Europe or North America, most of it comes from Asia. 90% of the world’s footwear is manufactured there too. We are RCS 100 (Recycled Claim Standard) and GRS (Global Recycled Standard) certified for these recycled materials and are in the progress of certifying our factories with the Fair Labor Association. We should obtain this by 2023. We have a Restricted Substances List (RSL) too, a reference system that guarantees that our suppliers do not use certain chemicals that are a harmful to health or to the environment.


What is the environmental impact of these Index.0.1 trainers?

The life cycle analysis of this footwear reveals that the mere fact of having simplified footwear design, has enabled its impact to be reduced for 6 evaluated criteria: climate change, acidification, eutrophication, use of resources, depletion of non-renewable energy sources and depletion of the ozone layer. Its impact on climate change has been reduced by 24%. If customers send the trainers back for recycling, this reduction stands at 38%, taking into account cleaning, shredding, and the bonus for recycling by reusing materials.


Is the Index.01 trainer designed differently in order to last longer?

It was out of the question to alter the durability of the product over time. This trainer’s life span is at least the same as that of our standard running shoes.


Are there technical limits?

The Index.01 trainer is the equivalent of a traditional product in terms of bounciness and fatigue over temps. But TPU foam isn’t as light as the others. The Index.01 weighs 290g compared to 170-200g for running shoes. The sole hasn’t the same level of grip as rubber. However it is largely sufficient for running on roads. It’s therefore more suitable for training than for competitions.


How do you plan on recycling the Index.01?

The aim was to keep each material as pure as possible in order to make it easier to recycle them. We have therefore very distinctively isolated and placed the TPU and the polyester in the trainer, making these easier to separate and sort. All of the underfoot is in TPU and the upper part of the trainer is in polyester and can be separated using scissors. We have made an effort not to integrate elastane into the materials in order to make their recycling easier. Furthermore, they are assembled mainly by sewing and we have replaced solvent-based glues with water-based ones, which we feel is healthier. The only drawback is the comfort-providing sole, which cannot be recycled, but is made from 100% recycled material.


How have you organised the collection and recovery of these used trainers?

We didn’t think that leaving such a product in the open seemed a very consistent approach because no doubt it wouldn’t have been recycled. So we placed a QR code and a website link inside the shoe box. Customers can thereby register themselves on our website. If customers do this, they receive a message 9 months later, reminding them that their product can be recycled and that if it’s worn out, they can download a free return voucher and return it via our after-sales service.

For the moment we’ve limited this product’s sale and distribution to three platforms in Europe, the US and Canada, and one in China. Each product to be recycled is returned to the continent’s original platform, where it’s cleaned and disassembled. In Europe, TPU is recycled in our factories in Romania, which manufactures mountain shoes. We work with European partners for polyester recycling.


How is the product viewed by customers?

We’re reach out to our customers’ good citizen side. They’re sympathetic to the approach, but changing mentality is difficult to do. For example, we haven’t provided any incentive for returning the trainers. However, we’ve seen that registration on the website just after purchasing, enabling to return the product when required, hasn’t reached the expected level.


What’s your next step?

We’re working on making the trainer lighter because its weight may be a criteria for not buying it. We’re also trying to reduce its price in order to make it more affordable to more customers, and to widen distribution. Lastly, we are looking to simplify its disassembly. For the moment this can be done using scissors, but this won’t be sustainable for larger production levels. This is a test year, allowing us to learn. We’re working on improving the product and on offering others for the 2022 and 2023 collections.


Thank you Olivier MOUZIN, Sustainable Footwear Manager at Salomon .


What did you think of the testimony?

Would you like to give us more details? Click here.

What is Eco design?

Eco design is a platform whose purpose is to provide information and assist textile and footwear brands to rise to the eco-design challenge. This platform is a Refashion initiative (formerly Eco TLC), a public authority-approved eco-organisation for the CHF industry (Clothing, Household linen and Footwear).

Our vision: a 100% circular textile and footwear industry.

Your Cookie Settings

Refashion uses trackers to customise its Site’s content according to your browser in order to enable you to share content on social networks as well as to measure the Site’s audiences and performance. For further information please see our Cookie Policy.

accept all
refuse all
Customise my choices

You may modify your preferences at any time by going to the “Cookie Policy” section at the bottom of the page.

Cookies: customise your choices

When browsing on our site, Cookies are created in your browser. Some of them require your consent. Click on each Cookie category in order to enable or disable their use. In order to benefit from all of our Site’s functionalities it is advised that the different Cookie categories are enabled. Refer to our Cookie Policy.

These Cookies are necessary to ensure that the Site functions in an optimal way. Therefore they are permanently enabled. They include Cookies allowing your site visit to be remembered during the sessions or, of you so wish, from session to session. If you refuse or uninstall these Cookies you will not be able to browse our site.
These Cookies allow us to improve the Site’s user-friendliness through the analysis of visitor use. In some case, these Cookies improve the speed at which requests are processed by allowing us to save your site preferences. Disabling these Cookies can slow the site down and limit the relevancy of recommendations.
Statistical cookies allow visits to be counted anonymously in order to know which pages are the least popular and to see how visitors browse the site without having to create a user account.
Cookies linked to social networks allow you to connect up to social networks and share the Site’s content on the internet. In some cases these cookies require the use of Personal Data. To obtain more information on the processing of your Personal Data please refer to our Confidentiality Policy.