Polymers in Sport and Leisure

Polymers in Sport and Leisure
In the 1980s, many synthetic grass pitches were
installed for playing soccer, including a small number
at English Football League grounds. Through a not very
convincing argument, synthetic pitches were banned
at the higher levels and that put a brake on their adoption
generally. However, at lower levels and for
multipurpose use they have continued to thrive and are
also used by league clubs for training.
The case for soccer is in marked contrast to that for
hockey where the adoption of synthetic pitches is
virtually universal and the increased speed of the ball
and the guaranteed smooth surface has transformed the
game. Synthetic turf is used for several other sports but
the volume is small compared to hockey and football.
can be varied to produce tracks having different levels
of durability and cost. When the top surface of a cast
track becomes worn, it can be ground smooth and a
new topping applied.
Clearly, tracks needs to be laid without undulations and
to a carefully controlled thickness - not a simple task
over the areas involved. However, with a cast system
irregularities in the base can be compensated for.
Tracks have also been constructed from prefabricated
sheets of a number of polymers including styrene
butadiene rubber, polychloroprene and polyvinyl
chloride. These are mostly used for indoor installations
where an uneven base is likely to cause fewer problems.
2.2 Athletics Tracks
Polymer tracks were first laid as long ago as 1957 and
one was used for the 1964 Olympics. Since then they
have become universal and completely superseded
previous constructions.
Polymeric track construction can be solid cast rubber,
resin bound rubber crumb or shred, or prefabricated
rubber sheet. Outside tracks are generally laid on a
macadam base. The original systems were cast rubber,
either polyurethane or a natural rubber or
polychloroprene latex, with a dressing of rubber chips
or granules. They have particularly good wear
resistance but are impermeable.
Bound rubber crumb systems are composed of rubber
shred or granules in a polyurethane binder and topped
off with a sprayed on layer of coloured rubber granules
in polyurethane. The basic construction is similar in
principle to that used for shock pads and children’s
playgrounds. Variation of the materials allows
considerable scope to modify properties and the track
can be porous to eliminate the need for a slope to allow
drainage. The athletics tracks require the higher level
of bound crumb, not least because of the need for very
high durability and resistance to spikes. The choice of
granule is very important and differences in size, shape
and surface texture can markedly affect both
performance and strength.
The casting may be done in more than one layer and
there can be a composite of a bound crumb underlayer
with a solid top. By variation of the constituents the
properties can be changed significantly and
developments have been aimed at producing tracks
which improve the athlete’s performance. The materials
2.3 Sports Hall Floors
Traditional sports hall floors were made of wood, often
sprung, or in the poorest circumstances painted
concrete. Over the last few decades there has been a
large rise in the demand for and the provision of sports
halls. The range of sports to be catered for has increased
considerably and people have increased their
expectation as to the quality of facilities.
The introduction of polymeric surfaces has seen the
use of just about all possible materials and
constructions. Where a hall or part of a hall is to be
devoted to one sport a surface can be selected which is
particularly suitable for that given purpose. However,
in most cases the hall will be multipurpose and it is
obvious that no one surface can be equally satisfactory
for all the sports to be played on it. The selection then
becomes a matter of compromise. This compromise
may have to include use for non sporting activities.
The properties to be considered include:
• Stiffness,
• Resilience,
• Impact absorption,
• Friction,
• Acoustic properties,
• Colour and gloss, and
• Durability.
When considering stiffness, distinction can be made
between point elastic and area elastic surfaces. A rubber
shock pad is essentially point elastic, i.e., the
deformation from an impact is essentially confined to
a small area. On the other hand a sprung floor is area
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