Artificial infill - Mitigate the migration

The ability of a synthetic turf surface to sustain high levels of usage and allow large numbers of people to play and enjoy sport has cemented their role in many communities. However, as with any engineered product, it's important that an artificial pitch is used in such a way that minimises the negative impact it has on its surroundings. One important fact to consider when it comes to both the usage and maintenance of your synthetic surface is minimising the migration of infill into the environment. Tom Shinkins of GKB Machines explores.

The EMEA Synthetic Turf Council (ESTC), working in conjunction with the European Standards Committee (CEN), has prepared Technical Report 17519: Guidance on how to Minimise Infill Dispersion into the Environment detailing how the employment of some simple design, operation and maintenance procedures can help to reduce the potential of infill contaminating the surrounding environment.

Laid out in the report is how the provision for minimising infill movement begins during the planning and construction of the installation. Once the pitch is in situ, consideration could be given to simple measures such as the fitting of low-level containment barriers around the perimeter fencing so as to help keep infill in, without restricting the visibility from any spectator vantage points.

Decontamination mats and/or boot cleaning stations should also be installed for the quick and convenient cleaning of boots post-game. Any recesses for catching infill at these cleaning stations should be suitably filtered to prevent rainwater from collecting and potentially carrying away the compiled material. Looking outside of the installation, any adjacent surface drains should also be suitably protected with covers and silt buckets to ensure infill from entering the stormwater drainage system during any adverse weather.

There are numerous other measures that could be employed in and around the construction phase, with good consultation with the manufacturer and/or installer able to identify the easiest and most effective methods of minimising migration at your specific venue. With the use of a synthetic surface, infill will naturally tend to disperse outwards towards the pitch perimeters which is where effective maintenance comes into play; ensuring that infill is returned to the higher use areas where it is required for surface stability and playability. The easiest way to do this is through regular brushing.

The most suitable brush for a surface will often be defined by the manufacturer, and this advice should be heeded in order to reduce the risk of causing unnecessary damage or wear to the installation. GKB have a range of brush options including the 4m wide Brush, for quick surface coverage with hydraulically foldable wings for convenient transportation and storage, and the GKB Quick-Brush, which can be configured with a range of optional extras including a rake or rubber finishing mat to suit individual requirements.

Also in the GKB stable is the Rotobrush, designed specifically for the brushing of the perimeter areas. The rotating brush head on the arm of the Rotobrush can switch between clockwise and anti-clockwise operation, with the rigid bristles effectively collecting the accumulated infill and moving it towards the centre of the surface. Together with redistributing infill, brushing the perimeters of an artificial pitch is also crucial to stop moss, algae and other contaminants taking hold.

Using the GKB Rotobrush to maintain the perimeter areas ensures much lower levels of infill migration when compared to other traditional methods of maintaining the extremities, particularly the use of a leaf blower, which should be avoided. Care should also be taken when using any brush with a vertical rotation, where coverage may result in infill flicking up and off the surface.

When brushing or using any other maintenance tools or cleaners, it is inevitable that some infill will be collected on the bristles and bodywork, so take care to ensure that machinery is thoroughly cleaned before it leaves the surface. Ideally, once the job is complete, the equipment should then be securely stored on a hard surface, in an area that doesn't drain into the surrounding environment. As already mentioned, silt traps can help to reduce infill getting into the waterways and these should be regularly checked and emptied as required to ensure they remain effective.

In addition to the natural migration associated with play and maintenance, the effects of mother nature can also impact on infill levels. A synthetic installation, like a natural grass field, will have an element of camber to help prevent puddling - however, the greater the camber, the greater the probability of infill accumulating at the boundaries following any periods of heavy rainfall. Managing snowfall is another situation to consider. Only if it is completely necessary should one attempt to clear snow from an artificial surface due to the inherent risk of removing large quantities of infill and potentially damaging the carpet fibres. If snow is cleared to the outers of the pitch, again, sufficient perimeter boards should be in place to restrict the migration of infill when the accumulation begins to thaw.

Together with reducing the negative impact that infill migration has on a surface's surroundings, employing some of the tools and techniques discussed helps to ensure infill remains where it is required and reduces the amount of additional infill required to keep depths at the levels specified by the carpet manufacturer. The ESTC report outlines six considerations to reduce the possible contamination level when carrying out infill top-ups:

• Visually inspect the delivery of infill materials to ensure that the packaging is not damaged or open
• Store the materials securely until required, in an environment where the packaging will not degrade or get damaged
• Open the bags in the confines of the pitch - do not transport loose infill from the storage location to the pitch
• Ensure the surface is secure and the appropriate containment measures are in place prior to the operation
• Collect and contain the empty infill packaging before removing them from the pitch
• Thoroughly clean the equipment used in the 'top-up' prior to transporting them back to the storage area.

When it comes to controlling the dispersal of new infill, similar principles to the rules discussed with brushing should be employed. Refrain from using broadcast dressers to spread new infill, for risk of throwing infill outside of the surface area. For the distribution of all types of infill - sand, SBR rubber, TPE rubber or cork - the GKB Infiller features a 3m3 hopper and accurate distribution adjustments to 'drop' a precise amount of material exactly where it is required. The Infiller can travel at a maximum speed of 15km/h, covering a working width of 1.5m per pass, whilst the rotatable driver's seat means it can be operated with ease in multiple directions.

Tom Shinkins

Further information around synthetic surface 'best practice' can be sourced through the EMEA Synthetic Turf Council - of which GKB Machines are a member. The ESTC is a trade association for the artificial turf industry across the EMEA region - its objective and purpose to serve, promote, develop, grow and advocate the work conducted by those operating in the sports and landscaping sectors.