Polymers in Sport and Leisure

Polymers in Sport and Leisure
elastic, i.e., the deformation from an impact spreads
over a considerable area. The use of a soft rubber sheet
on a sprung floor can produce both point and area
elasticity depending on the magnitude of the impact.
The sprung wooden floors achieve their impact
absorption properties from this area elasticity, but at
the same time they are stiff or hard enough that you
could, in principle, roller skate on them.
The disadvantages of the traditional floors were the
complicated installation, high cost, noisiness, vibrations
affecting non participants and possibly low friction.
Polymers have been used with wooden floors, often in
the form of foam pads, to provide a degree of spring at
lowered cost. The flooring is laid on battens which in
turn are supported by the pads. Such structures can be
prefabricated to simplify installation.
Polymers are also frequently used in the form of sheets
or carpet to provide an additional top layer to a wooden
floor which improves a number of the properties. The
obvious disadvantage is even higher cost.
Composition blocks, made of such things as sawdust
and cement bound together with a resin, were
introduced many years ago as a much cheaper
alternative to wood. They have enjoyed great popularity
because of the cost and durability but provide negligible
impact absorption.
Whatever the basic floor, a variety of polymers in tile
sheet or carpet form can be laid to provide specific
properties and good durability. These include rubber,
polyvinyl chloride and nylon or polypropylene carpet.
A great many products have been introduced and there
is strong competition. Simple sheet or carpet can
provide very satisfactory friction, noise and optical
properties for many sports and the impact absorption
is improved over hard solid floors. However, they are
still relatively hard and improvement can be made by
adding a foam backing. Carpets on polyurethane foam
backing have been found suitable for court games such
as tennis where ball response is very important. Rubber
sheeting can be textured and can provide resilience,
good friction, and can even be tough enough to resist
damage from spikes.
Further improvement in playing characteristics,
particularly in impact absorption, can be achieved by
various designs of laminated floors, which consist of
layers of foam, a rigid material such as chipboard and
a polymeric sheet or carpet top surface.
As said previously, the choice of a sports hall floor is
frequently a matter of compromise between the
requirements of several sports. A means by which this
problem is often ameliorated is to have secondary roll
out surfaces that can be placed for a particular activity
and removed afterwards. If, for example, the main floor
is a rubber sheet, a suitable carpet can be laid over it to
give a surface for playing bowls or cricket. Although
this adds to the cost, in the examples given the area
needed may be relatively small.
2.4 Equestrian Use
Bound rubber crumb or shred products of various types,
and even plaited strips of old tyres, have been used to
make entrances to arenas and road crossings safer for
horses. One example is interlocking rubber bricks from
scrap tyres (85). Shreds of scrap polymer mixed with
sand have been used to form training areas but it is not
clear how successful such products have been. A liquid
polymer/sand system was developed to make artificial
horse race tracks but this did not always retain its
performance characteristics.
2.5 Synthetic Snow and Ice
The opportunities for winter sports in the UK are
somewhat limited geographically and seasonally. As
these activities rose in popularity there was an increased
demand for ice rinks and for ski slopes. The high capital
cost of constructing an ice rink led to the use of plastic
substitutes. Polyethylene panels were claimed to look
and perform like ice but to reduce energy and
maintenance costs by 60% and to cost half as much to
install. The surface only required daily vacuuming and
weekly polishing with a silicone-based compound. A
high density polyethylene sheet material called Super
Ice (258) is in the form of coated wooden panels which
join together with a tongue and groove system. It is
claimed to have 90% of the glide factor of real ice and
to have a lifetime of at least 5 years.
In a skating facility, a very high wear area is at the
entrance to the rink where skaters can leave the ice at
speeds of 50 km/h and then use the picks at the toe of
the skates to brake. The flooring needs to resist the
cutting action of the skates but to cause no damage to
the ground skate blade. One solution was to use silicafilled
natural rubber tiles which have good wear
resistance and low water absorption.
Synthetic ski slopes have probably been more
successful than skating rinks. There have been two
basic types of construction: interlocking moulded
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