Fibres & Textiles
Fibres & Textiles Artificial Turf (Photo Philipp Thielen) Bioplastics – to be walked all over By Bas Krins Director R&D API Institute - Applied Polymer Innovations Emmen, The Netherlands The API Institute (Emmen, The Netherlands) is an independent institute dedicated to research into high-end applications of polymers. In recent years investigations related to the use of bioplastics have become an increasing part of the portfolio. Among other projects API is currently developing products for which the biodegradation behaviour offers an advantage. This can be an advantage in the costs of the whole cycle from raw material to waste, or it can be an advantage in the end-use for the customer. Temporary carpets At many trade fairs, exhibitions or other events (such as the 2009 Copenhagen Climate Change Conference) temporary carpets are used for a very limited period of time – a few days up to a few weeks maximum – after which they are dumped or incinerated. It would be a big advantage if the carpet could be made from plastics based on renewable resources. Such carpets from biobased plastics could be incinerated with energy recovery, thus delivering a carbon neutral source of renewable energy. Or, if made from biodegradable / compostable bioplastics, they could be composted afterwards instead. This however means that the multifilaments for the carpet have to be produced from appropriate biobased and/or biodegradable plastics. Also the fabric has to be redesigned, and last but not least the secondary backing that sticks the fibre loops to the fabric has to comply with the intended end-of-life scenario. 18 bioplastics MAGAZINE [05/12] Vol. 7
Fibres & Textiles The API Institute is involved in a project that is developing such temporary exhibition carpets from PLA based bioplastics, thus exhibiting both advantages, - renewable resources and the biodegradability/compostability. Here one of the advantages – apart from green credentials – is the reduction of the costs after use. Both, incineration with energy recovery and composting are cheaper than dumping the carpet in a landfill. Nevertheless, the price of the carpet is an issue and a fundamental condition of the project is that the final carpet should have a price that is not much higher than using traditional carpets. Unfortunately green credentials alone are general not a sufficient encouragement for users to choose the environmentally friendly solution as the market for the organisation of exhibitions is very price competitive. Artificial turf A somewhat comparable project is the development of a completely compostable artificial grass. At the moment the standard materials used are PE for the monofilaments (blades of grass), PP is used for the fabric and latex is used for the secondary backing in order to glue the monofilaments to the fabric. This system is very difficult to recycle, and in practice most of the artificial fields are burned after a period of use that can last up to 10 years. Recycling of the mats is sometimes carried out but it is an expensive procedure. Each soccer field produces up to 20 tonnes of plastic waste. In The Netherlands or Germany, for example, the number of soccer fields for amateurs using artificial grass instead of real grass is growing rapidly. In these countries with a high population density the fields are used quite intensively, and for that reason artificial grass is preferred. But this also means that the waste produced after the lifetime of the field is an increasing problem. The API Institute is developing, together with some industrial partners, a field that can be incinerated carbon-neutrally or that can be completely composted. In this case, there is probably no cost advantage for the investor of the artificial grass field. However the issue is that in The Netherlands most amateur fields for soccer are funded by local authorities and due to legislation these local authorities are forced to select a sustainable alternative if possible, although this alternative might be more expensive. For that reason there is a real market for these compostable artificial grass fields. The requirements for the grass mat are a real challenge. Their lifetime has to be about 10 years, and this means that the requirements regarding resilience behaviour are tough. Also the requirements regarding the degradation behaviour are difficult to meet: no biodegradation during 10 years outdoors, but subsequently a fast biodegradation under composting conditions. And the field has to fulfil the requirements from FIFA regarding ball rolling, ball bouncing, sliding behaviour, and so on. Since the technical issues have now been solved, the PLA based artificial turf developed by API is expected to perform the FIFA test shortly and API will construct a test field. Real grass nets From artificial grass to real grass. In many cases real grass turf is cultivated on nets. These nets are mostly produced from PP, which means that the customers will find this net under their turf many years after installation. Even if appreciated by some people for its protective effect against moles, there remains one big disadvantage. In case the user need to dig a hole in the garden or needs to scarify the lawn grass, the net will destroy the grass field. API is now developing a net for turf lawns that supports the process of installing the turf, but since it is made from a bioplastics that will completely biodegrade in soil, it will disappear after a few months. Details about the resin however cannot be disclosed at this time, due to confidentiality agreements. Final remarks In addition to the examples mentioned above the API Institute is working on a lot more projects related to bioplastics commissioned by customers. In all projects the polymers have to be selected and/or compounded in order to meet the requirements for their application. For this reason the API Institute is working closely together with suppliers of the bioplastics resins, and the Institute has a lot of experience in making the materials fit for these applications by compounding with other polymers or additives, and by optimizing the processing conditions of the bioplastics. Acknowledgement The grants from the European Union, Provincie Drenthe, Gemeente Emmen, SenterNovem/Agentschap NL, Interreg and EDR are thankfully acknowledged. www.api-institute.com (Photo iStock/EyeJoy) bioplastics MAGAZINE [05/12] Vol. 7 19
