Formerly artificial grass was made of nylon elements imitating the grass, but are now often made of polypropylene or polyethylene, more rarely polyamide or polyester, in the form of monofilament or fibrillated strip. They can imitate a mown grass, dense grass or young uncut grass.
Pellets of these polymers, melted at high temperature are extruded to form strands of artificial turf. There are two techniques; The first is the extrusion spinning, of pushing the polymers continuously through a die. Section of the long fibers of artificial grass thus created is determined at this stage through the capillaries. After stretching and cooling, the fiber is both flexible and durable. The other technique is to extrude a film, then cut into thin strips, to desired widths.
An important parameter is the fineness of the strands. The measurement used is decitex (dtex), which represents the weight in grams of 10,000m of yarn. The width of the wire monofilament often reaches 0.8 to 1.2 mm, while the strip goes up to 5 to 12 mm. The thickness of the fiber is between 50 and 150 microns.
The creation of artificial grass plans itself uses the technology of "tufting", widely used in the field of carpet manufacture: this is similar to the principle of the sewing machine, forming the thread loops through a woven or non-support fleece, according the desired parameters (height, number of points, etc..). For the final appearance of grass, the loops are cut in their height by a special machine and fibers stand. The fabric is then coated with complexes (latex, polyurethane) to firmly anchor the hair in its holder; this step is crucial to the long life of the product, especially on the sports field where the "Grass" will be subject to slips, cleats, hitting ...
Drainage holes are made to enable rain water to drain. It can then be inspected, wrapped, packed and shipped.
Finally, it is held on the ground carefully prepared, stretched panels that are sewn or glued onto a foundation which is more or less cas omplex, soft and thick, but still drained or draining. The appearance, flexibility and stability of the playing area is enhanced by the addition of granules (crumb) synthetic rubber, usually from recycled tires, and / or sand.