• Fri. Apr 19th, 2024

Best of multiple worlds

The first synthetic turf carpet for sports that is partly made of recycled end-of-life turf, has now become available. Will the product get fully sustainable? We spoke to Edel Grass, EOC Group and Tarkett about the development.

For a long time, the use of end-of-life turf to produce a synthetic turf carpet for sports was deemed to be a pipedream. The stringent quality criteria that are pursued for synthetic turf products for sports deemed the idea as being ‘impossible.’ Yarn producers are terrified of the idea of an impurity entering their production line. It only takes one sand particle to do some serious damage or to interrupt the production, with the consequence of significant product loss. A combi-yarn, consisting of a core that is made of post-consumer plastic and a mantle of virgin polyethylene appeared to be the closest thing possible. However, companies of the Victoria Grass Group have dared to take the step forward. “The innovations are a result of joining forces with Re-Match and specialized companies within Victoria Grass Group, with Schramm as developer of duo component yarn, United Works as tufting and backing innovator and Edel Grass as designer of certifiable systems like those approved by FIFA,” says Frank Pfeiffer who heads the R&D department at Edel Grass. Their Edel Athmos has a core that is totally made of processed end-of-life turf, while the mantle is still of virgin polyethylene. All in all, 50% of the yarn is made of recycled content.

Purity is the key

Important to the products, is the purity of the recycled end-of-life turf components. Backed by the Danish Government under “Innobooster” and the EU Horizon 2020 project, synthetic turf recycler Re-Match has worked for several years on fine-tuning its processes. The company uses airflow to separate the various components of end-of-life turf, including separating the polypropylene backing particles from the high-value polyethylene yarns. The targeted polymer is separated from impurities and other contaminants by means of CreaSolv, a patented solvent-based recycling technology developed by the German Fraunhofer Institute. It is a selective dissolution process that enables the recovery of high-quality recycled plastics from a wide variety of waste sources, including mixed plastics, composites, and contaminated plastics. “The CreaSolv process works by selectively dissolving the target polymer in a solvent while leaving other materials, such as additives and contaminants, suspended in the solution. The dissolved polymer is then recovered by evaporation, leaving behind a clean, high-quality resin that can be used to manufacture new plastic products,” the German Fraunhofer Institute told Sportsfields.Magazine. As CreaSolv removes almost all impurities and contaminants, it can produce recycled plastics with virgin-like properties. Edel Grass has signed an exclusive collaboration with Re-Match for the recycled turf resin suitable for yarn production. Although it was common knowledge that Re-Match was exploring what was possible in terms of reintroducing end-of-life turf in the production of new yarns, ever since Edel Grass announced their Edel Athmos and Edel Xero products, interest increased, with other companies now vying for the reclaimed raw material.

The same raw material

Combining two different yarn components could result in technical catastrophes. In theory, delamination, where by the different layers of the yarn, due to stress, moisture, or temperature, separate from each other, is possible. If that occurs, the yarn can become brittle. Yarn brittleness is also possible due to UV degradation, hydrolysis, or other factors, while stress, abrasion, or chemicals could result in the two layers separating. This can result in the yarn looking patchy and uneven. Pfeiffer is confident that this will not happen to his yarn. “The two materials are not separately applied but connect as one as they have exactly the same chemical structure,” he says, pointing out that both are produced from polyethylene. Despite the one being derived from end-of-life turf and the other one from virgin polyethylene, the window to process both is big enough.

‘Rather PE derived from recycled post-consumer plastics’

Morton Extrusiontechnik has also explored the idea of using PE from end-of-life turf, but abandoned the idea.

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Although Edel Grass introduced their Edel Athmos only recently, Pfeiffer is confident that it will stand the test in a football turf field. “We subjected the carpet to 15,000 Lisport XL cycles, which is more than double of what FIFA requires.” Usually, a FIFA Quality Pro surface is subjected to 3,000 cycles, while a FIFA Quality surface, which is commonly used for games at grassroots level, should be able to endure least 6,000 cycles.

Is 100% recycled possible?

With the benchmark set at 50% recycled end-of-life turf reused in a new synthetic turf product for sports, the challenge is on to increase the volume of recycled material in the yarn product in line with the UN Millenium Goals. “The goal is to raise the percentage of recycled component step by step and eventually create a circular process,” the head of R&D at Edel Grass says. “However, at present, it is still not possible to re-use 100% of recycled turf components to produce new turf yarn, as colours can deviate,” he points out. Colour imperfection is caused by the different levels of carbon black that are in the source material. This is why any new product produced from reclaimed synthetic turf, will have a darker green colour than what the market for synthetic turf carpets is used to. William van Diemen is familiar with this argument. His Greenmatter range of products, like park benches, flower boxes or shore protection, to name a few, all contain a significant amount of end-of-life turf. “The exact colour is less of an argument for our products, but to avoid any discussion afterwards, we point out in our quotes that the client will buy something that will be made from recycled material, and, as such, can have a colour deviation.” If buyers of synthetic turf for sports that contain a significant amount, if not 100% end-of-life turf, would worry less about the exact colour of the product, the synthetic turf industry could certainly take a giant leap forward.

Developments like the Lifecycle Cycle Analyses and the Environmental Cost Indicator Analyses (ECI) Product Environmental Footprint Category Rules (PEFCR) for synthetic turf help van Diemen to explain why customers are better off with a product made of end-of-life turf. “Such a tool will help us substantiate our claim that a product from our range will be cheaper than something that is made from virgin material.” Elsewhere in this edition, you will read about PEFCR and how it will be rolled out. Scoring the colour of a product is not included.

Predicting by when we will have synthetic turf yarn that is 100% made of end-of-life turf is impossible, but Edel Grass has made a good start. “We will continue increasing the total content of end-of-life turf. And with the price for certain techniques becoming more affordable, we’ll also be able to better control the colour. Nevertheless, focusing on the colour over performance will not serve the end-user, nor will it do justice to the UN Millennium Goals,” Pfeiffer states.

Backed by a backing from recycled components

Like with the yarn, the industry also uses backings and coatings that contain recycled content. Domo Sports Grass has been marketing a backing made of reclaimed polyethylene for several years already. Its an interesting development, as the need for dimensional stability is usually the reason why tufters prefer a backing made of polypropylene.

One component where producers can still make significant inroads, is the secondary backing. In the past, this used to be a latex. EOC Belgium has introduced an alternative to fixate yarns to the backing which, they claim, is more sustainable. “Our TPE coating is solvent and water-free, which means the coating process doesn’t need after treatment. Once coated, the product is ready immediately,” says Piet Tytgat of EOC Belgium. Backings from recovered synthetic turf carpets that have been coated with this product, can be shredded and reused for the coating of another synthetic turf carpet. “Waste generated in the production, like trimmings, can be immediately added to the process. Moreover, as the application process doesn’t require water or gas to dry the final product, the total environmental footprint will become much smaller,” Tytgat adds. The Edel Xero is also a secondary backing, but is different, Pfeiffer says. “It was developed in-house and contains 43% recycled end-of-life material which is basically the same as the component used in the Edel Athmos yarn.”

Guy Oldenkotte

Guy Oldenkotte is senior editor of sportsfields.info and has been covering the outdoor sportssurfaces market and industry since 2003

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