Introduction

General

Synthetic turf sports surfaces provide attractive, hard-wearing and safe playing areas that can accommodate high levels of use and be used in far more diverse climates than natural turf. The development of these surfaces has led to significant demand with over 16 000 full size sports fields now being used in Europe, and approximately 4 000 new fields being built each year.

Synthetic turf sports surfaces take four generic forms:

— non-filled short pile;
— sand filled or sand dressed short pile;
— long pile with infill (typically rubber and/or sand);
— long pile non-filled.

Infill is applied to the synthetic turf surfaces for three reasons:

— it is used to stabilize the carpet to prevent dimensional expansion and contraction and movement through use i.e. it acts as a ballast. This type of infill is often described as stabilizing infill;
— it contributes or provides the sports performance and impact attenuation characteristics of the sports surface. This type of infill is often described as performance infill. The performance infill is a key component of the surface as it provides comfort and protection to players as they run and fall on the surface;
— it helps control the way the ball interacts with the surface, supporting the pile of the surface so it remains upright.

Short pile synthetic turf surfaces typically have pile heights of between 10 mm and 30 mm and normally only have one layer of infill. This is often a rounded sand. Sometimes the sand has a polymeric coating to change the colour of the infill (i.e. it is coloured to match the synthetic turf colour).

Figure 1 shows the typical cross section of a short pile synthetic turf sports surface.

Figure 1 — Typical cross section of short pile synthetic turf surface

1	synthetic turf carpet pile, may be curly
2	infill
3	shockpad (optional depending on intended sports use)
4	base (or foundation)

Long pile synthetic turf surfaces typically have pile heights of between 30 mm and 60mm. Most contain two layers of infill, the lower layer (normally sand) is installed to provide ballast and stability to prevent the synthetic turf carpet moving. The upper layer is the performance infill.

There are a number of different granulated materials used to form this layer including various rubbers and thermo-plastics and natural materials such as cork, timber, nut husks, etc.

Figure 2 shows the typical cross section of a long pile synthetic turf sports surface.

Figure 2 — Typical cross section of long pile synthetic turf surface

1	synthetic turf carpet pile, might be curly
2	performance infill
3	stabilizing infill
4	shockpad (optional)
5	base (or foundation)

Most infills are in the particle size range 0,5 mm to 2,5 mm with some occasionally being larger.

Environmental concerns

Increasing public concern about microplastics has led the European Commission, to investigate ways of reducing the quantities released into the environment. They have defined a microplastic as any solid particle made of a non-biodegradable polymer that is 5,0 mm or less in size. They can be unintentionally formed through wear and tear or deliberately manufactured and intentionally added to products for a specific purpose.

As many infill materials used within synthetic turf sports surfaces are either made from non-bio-degradable polymers that are less than 5,0 mm in size, or incorporate some form granule (e.g. sand) that has a polymeric coating, it is important that the design and maintenance of sports fields having these infills is undertaken in a way that minimizes the possibility of the infill migrating from the sports surface and being dispersed into the environment. This document describes ways of containing infill materials within the footprint of the synthetic turf field during its construction, operation and end of life removal.

BS CEN/TR 17519:2020

Surfaces for sports areas. Synthetic turf sports facilities. Guidance on how to minimize infill dispersion into the environment

Current

Published:

29 Feb 2024