Web Exclusive - September 2014
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Turf: A Crash Course

Synthetic turf fields offer a wide range of benefits. Here's a look at some specific types of turf and their applications.

Fiber Types

Three styles of face fibers are available. Ranked from the least to the most durable, these include monofilament, monofilament/slit film blend, and slit film.

Most appropriate for lighter-use applications or soccer fields, monofilament systems feature fibers that are extruded through a spinneret in single strands. The pros of this type of system include: great aesthetics; and that it can be extruded in a shape to help it stand up better. For example, a horseshoe-shaped fiber (used by AstroTurf) features two posts on the edges of the fiber to help it stand upright. Because monofilaments, at least early in their use, stand up straighter, they help slow ball roll. This is especially beneficial for soccer. At the same time, though, monofilament systems are the least durable. One particular problem that all synthetic turf manufacturers have had trouble with (whether they'll admit it or not), is turf bind. Turf bind is the amount of force it takes to pull the fibers from the coated backing. With a monofilament system, if one fiber in a tuft is pulled out, the entire tuft becomes loose and is compromised. This is because when the fibers are punched through the backing during manufacturing, they tend to stack like spoons, so the coating applied to the backing tends to surround the outside of the fibers, rather than working its way down between the fibers.

Slit film systems, recommended for very-heavy-use applications, are extruded in a sheet that is cut (or slit), forming a sort of honeycomb pattern. Upon installation and use, the fibers break apart, or fibrillate. This is the most durable type of system, but it is less aesthetically pleasing than the less durable monofilament or hybrid-type systems.

Hybrid or blended systems feature both monofilament and slit film fibers in the same products. This is the newest trend in face fibers to hit the market and offers the best of both worlds. It is recommended for virtually any application, although fields that experience extremely high use might still benefit from a slit film system. Some of the pros of the hybrid system include good aesthetics, good ball-surface interaction and good resistance to wear.

Root Zone

Another important factor for field owners to consider when selecting their synthetic turf system is whether or not the field has a root zone. This is a system of crimped fibers that serves to hold infill in place and reduce its migration.

Infill migration takes place when the rubber gets kicked out or creeps to the sides of the field over time. It is very important to keep infill (especially the rubber) in place, so that it remains even and consistent across the field and over time.

By keeping the infill in place, the field benefits on multiple fronts:

  • Durability: Even infill helps the fibers stay upright longer, limiting their UV exposure.
  • Shock Attenuation: Without a pad, the rubber infill is what diffuses the force when an athlete falls. Having bare spots (which typically show up in high wear areas, such as goals, is definitely not recommended.
  • Lower Ligament Torque: A Michigan State University study revealed that turf system with a root zone prevent infill from compacting, which in turn helps promote proper cleat release and reduces torque (the twisting force) transmitted to joints.

Root zone systems are a great investment and can be used with any of the fiber types—monofilament, slit film or hybrid. While they might increase the price of the field upfront, they will help it last longer and pay off over the long term.

Source: AstroTurf