How does artificial grass work?
First Generation Turf:
​
First generation synthetic grass was a massive improvement from what was laid down in the Astrodome. The introduction of polypropylene instead of nylon meant a softer surface, reducing risk of injury. But perhaps the most important property of polypropylene is its high fatigue resistance, meaning that it can be used for a very long time, reducing long-term costs. However, the fibres were very closely packed and short, which meant a very dense, unrealistic playing surface and caused irregular bounce and the asphalt underlay offered little compression.
Third Generation Turf:
​
The latest generation of artificial grass is by far the best yet, with obvious improvements over previous generations. Although there are still fibrillated fibres, the pile height has doubled to 40-60mm, with the fill height decreasing from 90% to between 60% and 80%, meaning that studs could now sink into the surface. This reduces the impact on the ankles and feet, hence reducing the risk of injury, and also allows the foot to get under the ball. The blades are more spaced out, adding further to the authenticity. A change in material to polyethene was implemented, as this material is much softer when the skin comes into contact with it. Recycled rubber granules were added to the sand infill, further adding to the authentic feel.
Artificial grass has developed a lot over the past 50 years, with 3 generations having been developed over that period but what makes each one unique? This page looks into the structural differences between each generation of artificial turf.
​
​
Pre-generation Turf:
​
The first instance of artificial turf used in public was in the Astrodome, for the Major League Baseball side, Houston Astros, in 1965. This pre-generation turf was a carpet made of nylon fibres. However, there were many drawbacks. For example, nylon was a very expensive material over a large area and the nylon didn't provide enough of a cushion when players fell on it, causing an increased risk of injury.
Second Generation Turf:
​
The second edition of artificial grass was a much larger step towards simulating natural grass. The design used fibrillated fibres, with a pile 300% taller allowing compression of the pile underfoot, mimicking real grass, which was also aided by the introduction of a 35mm elastic layer. Sand was also introduced between the fibres, in order to aid stability and to support the upright fibres. This turf became increasingly popular for field hockey, as it would give the player more control over the ball, as the surface is smoother. However, its shortcomings were obvious in football, where many players obtained carpet burns due to surface friction with the sand and the spin added to the ball on the surface wasn't realistic enough.
Extra information:
​
You might still be wondering how this structure prevents the flooding of the playing surface. The drainage of these pitches relies on the fact that there are small holes punched into the surface, which allows water to seep through the underlayer (due to it being made out of permeable materials, such as crushed rubble and gravel) and into integrated drainage pipes.
In addition, synthetic grass is made using UV inhibitors, in order to prevent colour fade, and antimicrobial fibres, which prevent the build up of mould and mildew, keeping the surface clean. On average, modern surfaces last about 10 years, after which time, only the turf needs to be removed, as the underlay is still in good condition.