Performance artificial turf components - fibrillated tape

Artificial turf surfaces with "soft" yarns are increasingly used because of haptic attractiveness and player friendliness. Linear low density polyethylene (LLDPE) with low density is preferred to achieve the desired softness. The choice of LLDPE material is guided by the performance requirements outlined in the FIFA Quality Concept for football turf [1]. Different LLDPE materials were extruded into fibrillated tape yarns on pilot and production scale machinery. A key mechanical property of fibrillated yarns is the tear resistance in machine direction influencing the fibrillation process and the ultimate yarn splitting and resulting wear in the field. A high tear resistance makes fibrillating the yarn difficult however improves the ultimate split and wear resistance in the field. Unfibrillated oriented yarns of different composition were analyzed for tear and other mechanical properties. The results are related to previous work on durability of certain yarn compositions which demonstrate the benefits of low density LLDPE resins in terms of durability and wear resistance [2]. As proof of concept one metallocene LLDPE resin with one of the highest tear resistance values currently commercially available was extruded into oriented yarn and subsequently fibrillated. Processing conditions and choice of particular LLDPE greatly influence yarn fibrillation and performance. As already demonstrated in monofilament yarns [2], shrinkage is identified as an important measure to characterize residual stress in low density LLDPE yarns. We discuss strategies to minimize shrinkage for fibrillated tape made with low density LLDPE and refer to its relation to performance in the Lisport test used to determine the durability of an artificial turf yarn. (C) 2009 Published by Elsevier Ltd.