‘Incorporating natural fibres in end products is no easy task’, according to Leon Joore (Millvision). ‘That is why a separate natural fibre cluster has been set up in the Biobased Delta which concentrates on the whole supply chain: from plant to customer. This is because every process step has consequences for the next step and in the end the application in which fibres – often combined with other materials – are used.’  An important part of the natural fibre cluster is the Natural Fibre Application Centre (NAC), which houses laboratory and pilot equipment for testing whether applications do what they are supposed to do. The NAC originally targeted wood (paper) and agricultural (residual) fibres for paper, cardboard and composites. Now the NAC also includes other fibres such as hemp, flax, miscanthus, bamboo and sorghum.
Boskalis
A material in itself is not yet an application or a market. These include packaging, construction and infrastructure, paper/cardboard, ornamental gardening and automotive. Over the years, various applications have been developed at the NAC which are now being tested in the field. A number of projects in the infrastructure sector have reached the regional and national media. Boskalis was recently awarded the contract to widen a certain section of the Tractaatweg road in Zeeland. The province of Zeeland, the client, challenged the company to come up with biobased solutions. Thus the anchoring system and the geotextile are (partly) based on biopolymers. The N18 road near Lichtenvoorde (province of Gelderland) is likewise a good example of biobased in infrastructure, with the use of wood fibres in concrete and sound barriers.
Zeeland leads the way
Esther Stapper, colleague of Joore at the NAC, suggests that (regional) governments have a major part to play in infrastructure – and construction – by facilitating these kinds of projects. ‘We need these showcases to show other parties that it really works. Some provinces, such as Zeeland, are leading the way in this respect. It is important that the other provinces follow suit. Market parties will have to make it clear what biobased is, to make this process easier. The NEN standard is a minimum 30 percent (biobased) of the volume. At least as important are sustainability parameters, such as an LCA (including CO2 footprint) and the end-of-life: can you recycle the material? If so, into what kinds of products? Stapper believes that governments also need to take the necessary steps when it comes to sustainable purchasing. In practice it often goes wrong, because price is the most important factor, or because buyers are not familiar with the material. Good news in this area is the Responsible Procurement Manifesto 2016-2020 which various provinces, municipalities and water boards have signed. Key points in the Manifesto are combating climate change and environmental pressure.
Concrete cluster
According to Joore, governments can also play a more active part in the phase preceding the pilot project, namely in the area of applications. ‘Public funds mainly go to research, which leaves a gap in the intermediate phase. As a result, few (partly) biobased products enter the market. That explains my plea for a focus on application research in which SME businesses will be linked together. The market demand will be the guiding factor: what do end customers want exactly and to what extent can natural fibres play a part in that? A good example of this kind of practical market demand comes from Concrete Valley, a large production facility in Bergen op Zoom. Since 2012, this location has been the home base for a range of innovative companies in the concrete industry. Currently three companies are operating in the Valley: mbX, microbeton and Waco.
At mbX, specific concrete products are produced for ornamental and constructional elements. Director Pieter Nap: ‘We stand out mainly because of our distinctive shapes. We have developed a specific flexible mould for them, which allows us to produce these elements. For instance, we produced the double curved elements for the public transport terminal in Arnhem.’
Weight reduction
Microbeton makes elements like balconies and façade components. Nap: ‘We want to make these elements as light as possible, but they must have the same functional properties. Microbeton reduces the load factor of the façade and can often be installed on existing structures without too many adjustments, using our patented chute system. Currently we supply these elements with a polystyrene core. That reduces the weight by 60 percent. We are investigating whether we can replace the polystyrene with even lighter biobased materials. We are collaborating with Waco, together with NNRGY BV and the Technical University of Eindhoven, to see whether we can use miscanthus fibres: on the one hand as reinforcement, and on the other as an alternative for sand. It will probably work for ornamental elements, such as frame elements for windows, which do not have to bear as much weight.’
Hurdles
Bioplastics such as PLA or bio-PET or PE are no strangers in packaging materials any more. Natural fibres have since tentatively made their appearance, for instance in the Rondeel egg cartons which are based on a mix of potato starch and grass fibres. Unipak from Steenbergen in West Brabant is also looking for natural fibre applications for its range. The company targets the food sector especially: a high volume market in which every cent counts. ‘The bulk of our range is based on PP and PET. They are proven materials which are very cost-competitive and also quite easily recycled. This is because they are mono-materials: the recycling becomes more complicated and more expensive if a product is made from several materials,’ according to packaging consultant Eddie Clarijs. The above materials, however, are not compostable. That is why Unipak is investigating whether it can extrude foils which are based partly on natural fibres and partly on potato starch. These foils could be used for fresh products and the packaging could go along in the compost stream. The first tests have shown that it is possible, but also that there are still a few hurdles to be taken. For instance, the foil is not transparent, sometimes it has holes, and the fibres can become stuck in the extruder. Clarijs: ‘The fibres should not be too long or too stiff. That is an important lesson.’
Horticultural applications
Bato Plastics from Zevenbergen in North Brabant produces plastic products for horticulture. These products are predominantly of fossil origin and not decomposable. The company also has some products in its range which are based on compostable plastics, including pots, clippers, wire tensioners and cluster supports. These have end-of-life advantages compared with the fossil-based plastics, because they can be disposed of along with the plant matter (stalks, leaves, etc.). The fossil-based equivalents have to be removed and disposed of, resulting in extra costs, especially labour costs.
Gert-Jan Spierings, director of Bato: ‘We are working together with Rodenburg Biopolymers and Millvision to use natural fibres from paprika cultivation for the above bioplastics. Of course there are challenges: the longer production time, the stability and homogeneity of the material and the odour which is released in the injection moulding. But the use of natural fibres also has its benefits. The larger the content of natural fibres, the faster the composting process in the ground – considerably faster. To sum up, we definitely see a future for this kind of application in our range.’
