Artificial grass was first used at the end of the 1960s in the Houston Astrodome, the first covered sports stadium in the USA. This type of artificial grass was named Astroturf, after the stadium. The objective was to create a sports playing field that was as functional as possible; functionality and not the look and feel of the turf was the key factor. Apart from being green, the playing field did not resemble natural grass in any way at all.
It was made from nylon (PA = polyamide) and was in fact basically a thick layer of carpeting. Nylon had the unpleasant tendency to cause ‘burns’ when it came into skin contact, for example, when baseball players had to slide into base. Furthermore, nylon was also a relatively costly material, which meant, at that time, an artificial grass playing field represented a sizeable investment
In the 1980s, a new type of artificial grass for sports made from polypropylene (PP) yarn with a 90% sand infill was introduced. PP was less expensive than nylon. The sand infill was used to stabilise the playing surface, or, in other words, to achieve a more natural ‘ball bounce and roll’ for tennis and hockey, and it also made the artificial grass system even cheaper. The disadvantage of sand was that it acted like sandpaper on the skin when players had to make a sliding tackle and it meant that these surfaces were not suitable for football.
At the end of the 1990s, the third generation of artificial grass playing surfaces was developed for field contact sports such as soccer, American football and rugby. The difference from artificial grass pitches laid the 1980s was that players could make sliding tackles without burning or grazing their skin. This was mainly due to the use of polyethylene (PE) as a raw material for the artificial grass fibers and an infill consisting of granulated rubber instead of sand, or a layered combination of both.
MORE AND MORE LIKE NATURAL GRASS
PE was a slightly softer raw material as well as colour-fast compared to PP or PA. The artificial grass fibers were also longer, up to 70 mm compared with the 12 to 24 mm used in PA and PP playing surfaces. The sport functionality – the interaction between the player and the surface, and the behaviour of the ball – remained a key factor in the development of this type of artificial grass. Compared with the first two types of artificial grass, third-generation artificial grass looked much more like natural grass due to the longer fibers.