The Tampa Bay Rays have played on synthetic turf since their inaugural season in 1998, but the surface installed at Tropicana Field this past offseason is different. Fans may not notice from their stadium seats or living room couches, but each synthetic fiber in the new field is shaped like the Greek letter Omega. The design goal behind these thicker, concave filaments is to keep them upright, ensuring predictable performance as base hits bounce on them and bunted balls roll over them.
On the surface, it may seem like a subtle change, but the latest advances in synthetic turf are deeply rooted in fiber technology. The departure from smooth, rectangular blades that tended to lie flat hasn’t come overnight, but field manufacturers have been drawing unprecedented attention to their fiber tweaks this year in particular. One turf company touts the manufacturing of its latest fiber as “the biggest technological advancement the industry has seen in decades.”
Separating state-of-the-art yarn manufacturing from marketing spin can be challenging. For years, at least, fibers have taken one of two forms – monofilaments or slit-film tape. Monofilament fibers are extruded as singular strands, while slit-film fibers are cut from sheets of polymer to a predetermined width and then perforated by design. During slit-film installation, the perforations are combed through, or fibrillated, to form the individual filaments that will comprise the finished playing surface. This process is not to be confused with post fibrillation, which is the unintentional and undesirable fraying of fibers over time due to wear.
Currently, fields composed of slit-film fibers are believed to outnumber monofilament fields, for no other reason than slit-film technology has been around longer. Some fields feature a hybrid of both fiber types.
The manufacturing process for both types involves taking raw materials – namely, the polymer (polyethylene is now used exclusively for long-pile turf) and color – and melting them in an extruder. The melted material is then either formed into a film and cooled or pushed through a spinneret and cooled. The spinneret features an interchangeable die plate in which holes are cut in the shape desired for the finished fiber. Monofilament turf fibers, which have emerged as a popular alternative to slit film only within the past five years, are manufactured in dozens of different shapes – from horseshoes to dog bones – when viewed in cross section. Rectangles, triangles and diamonds are common, as are turf blades exhibiting one or more vertical spines along their length. One fiber introduced this year combines a concave shape with multiple spines, much like a natural grass blade.
With the industry growing and evolving at a rapid pace it will be amazing to see what technologies comer into play in 2015!