In their quest for more natural products, synthetic turf installation companies have now also turned to corn. Dutch installation companies are now experimenting with pieces of corn cob.
The companies use the woody component of the corn cob to which the kernels are fixed. It is a residue that, until recently, had no value once the corn has been harvested.
Installing companies Tarkett Sports and GreenFields have added the product to their portfolio with natural infill materials. They recognise that the specific gravity of these particles derived from corn is higher than that for cork.
Cork has the tendency to float during a heavy downpour on synthetic turf fields, while the subbase still holds air pockets.
After using corn cobs in a small-sided MUGA-court, Tarkett Sport subcontractor TopGrass has now used the material in a full-size field. “We used it because the synthetic turf is installed on top of a water-system,” explains Teun Wouters of TopGrass. A water-system uses coarse lava or graywacke to establish a subbase in a watertight container. During wet periods, the voids between the rock particles are used to store excess water.
“That is why it is important that the infill does not start to float when there is a lot of precipitation.” According to Wouters, the corn residue is also more durable than cork.
A fear that the corn would possibly attract animals is unjustified, he adds.
“These particles are derived from cobs for sweet corn and can only be eaten by ruminants, which you won’t find near synthetic turf fields. Even if they were there, the fence around the field prevents them from accessing the field. Birds and rodents don’t like eating this product, as they consider it too tough.”
Sweet corn can mainly be found in France, hence the corn infill used is currently imported. At present, it is unclear whether sweet corn capacity (in the Netherlands) will facilitate obtaining the infill closer to home. This could become an issue, as transport is the biggest contributor to the CO2-footprint of a project.
Pleasant in use
TopGrass used corn for a Tarkett carpet that consists of a combination of 45 mm long fibrillated and monofilament yarns. “This way, the infill is nicely enclosed and prevented from migrating around the field.” Therefore, Wouters expects that the infill would hardly need to be supplemented during annual maintenance.
The infill has the tendency to expand once it comes into contact with moisture. As a result, its shape becomes rounder. “Feedback reports we have received thus far indicate that players appreciate the infill much more compared to others.” In dry periods, it will gradually release that moisture. “That will lower the ambient temperature by 7 to 8 degrees.”
The infill height is only 5 mm. “This is not enough for infills like TPE, where you will end up placing your studs in the layer of stabilizing sand, but because this corn product has more body and expands due to moisture, this is sufficient for this purpose. Players can now place their studs between the infill, making the pitch feel more resilient.”
Combination with cork
Greenfields has opted to create a mixture with cork. “Our mixture has a 50% maize and 50% cork ratio,” says Rutger Schuijffel. According to Schuijffel, the choice to mix the two components has been well considered. “Contrary to cork, corn, olive kernels or Brockfill infill by themselves will not be enough to deliver the required shock absorption. However, cork has the disadvantage that it is too light, which means that it can float. The combination of cork with corn infill keeps the infill loose, gives it the desired cushioning, and it will float less when it rains.”
Greenfields uses 11 to 12 mm infill in its fields.
According to Schuijffel, cork in the mix also makes the maize feel less sharp. “In dry weather, all natural infills feel a bit sharper, but the cork component in mixtures tends to mitigate these feelings.” This, Greenfields and its holding company, TenCate Grass, was told by players from top football club PSV Eindhoven, who trained on a field with the cork-maize combination. TenCate Grass has a field lab at the training facility of the Dutch football club. “This allows us to test new developments and receive feedback from professional players,” Schuijffel explains.
Material of the future?
When asked whether corn is the infill material of the future, Schuijffel is clear. “It’s certainly a good step forward, but for us, it’s not the final solution, as we strongly believe that non-infill fields will be the way forward.”
Wouters is a bit more positive. “We are constantly looking for new materials to achieve a circular economy. Corn offers a solution and I am hopeful that it will prove itself.”
The field at V.V. Boskant is a pilot project and will be monitored the entire season.