What are the types of infill that go into an artificial turf field?
The infill is the equivalent to the earth of a natural grass playing surface. The goal is to have the infill feel and perform like the “earth” of a natural grass field. The infill will determine how firm or fast a field plays, how the ball bounces and rolls, and it impacts how safe the fields are. The amount of infill needed is determined by how tall the fibers are, whether or not there is a shock pad being used, and the sport being played.
Infills typically fall into 5 categories. Each of these infills vary greatly, in both performance and cost.
- Coated Sands
- Coated SBR Rubber
- Thermo Plastic Elastomers (TPE)
- Virgin EPDM Rubber
- Organic Infill
Understanding the different types of infill
The infill system is one of the most important aspects of all synthetic turf fields. It is the basis for the safety of the turf system by providing the appropriate cushioning to absorb impact. The infill provides the foundation to a field’s performance level by offering traction for players to cut, plant and release just like they would on natural grass.
Coated Sands – are made from uniformly sized natural sand and typically coated with acrylic, polyefin or an elastic coating. These systems are usually a full depth infill system – not mixed with other mediums. This infill does not require an irrigation system. Shock pads are HIGHLY recommended if you are using a coated sand infill system. Most manufacturers require a shock pad, when using this infill. Coated sand is subject to similar quality issues as TPE and as EPDM. All three may clump over time. Coated sand can add approximately $150,000 to $200,000 per field (this would include the cost of the shock pad.) Coated sands are typically much cooler to the touch then SBR basic rubber system. The maintenance of coated sand is similar to SBR systems; with a top dressing recommended in year five (5).
Coated SBR Rubber – is very similar to the traditional SBR rubber infill. The SBR rubber product is typically coated with a virgin EPDM rubber. This system does not require an irrigation system. A shock pad is not required. However, if you are trying to pass a HIC Test a shock absorbing pad would be needed. Coated SBR can add approximately $40,000 per field. These infill systems are easy to maintain. The field will need to be top dressed every 5 years- at a cost of approximately $15,000.
Thermo Plastic Elastomers – (TPE) is similar in size to SBR rubber, but it is harder and typically rounder. Thermo Plastic Elastomers are usually mixed with standard synthetic turf sands – to make up the infill system. TPE comes in many colors and many variations for the aesthetics of a synthetic turf application. Since TPE is a plastic, there is a risk over time of the TPE “melting” together. This system does not require an irrigation system but will most likely require a shock pad. Some TPE manufactures claim their product can result in a 10 percent drop in temperature when used as an infill for artificial turf. Maintenance of this system is very similar to the SBR systems…a top dressing is recommended every 5 years.
Virgin EPDM Rubber – is rubber that has not been recycled. It is similar in size to SBR rubber. This is the most common infill system that is used in the artificial turf industry. Rubber is mixed with standard synthetic turf sands. EPDM comes in many colors and many variations for the aesthetics of a synthetic turf application. This system does not require an irrigation system A shock absorbing pad is recommended. Maintenance of this system is very similar to the SBR systems with a top dressing recommended after 5 years of play.
Organic Infill – Most organic infill options are made from cork, walnut shells, coconut fiber, wood and or other similar products.
Organic infills help produce the feel of natural grass, under foot. They make the fields play and perform more like natural grass too. Because organic infills don’t conduct heat like the other infill systems, they are great at reducing field temperatures. Some organic infill systems claim they can reduce field temperatures up to 50-degrees.
Most organic infilled systems will require an irrigation system. Water is necessary to keep the infill “hydrated”. This also assists with the temperature reduction. Since most of the systems need water, as part of the recipe, the fields can be subject to freezing in the winter months.
Because organic infills are very light weight, “floating” may occur. This can happen whenever there are heavy amounts of rain, in a short period of time, the infill will “float” or migriate to the sidelines. Shock pads are required when using organic infilled systems.
This type of infill system can add $120,000 to $400,000 to your project – depending on the infill, irrigation, and the shock pad selected.