Polymers in the Field and Track

Transcription

Polymers in the Field and Track
Polymers in the Field and Track
prepared by Mary Harris
Missouri Polymer Ambassador
Before renovation in 2005
This presentation includes:
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History of artificial turf
Preparation of the field
A closer look at the turf
Playing on the new surface
Recycled tires for the turf
Virgin rubber track
Temperature and heat studies
History of Artificial Turf
• 1950’s Ford Foundation and
Chemstrand Company (Monsanto)
• 1964 Chemgrass
• 1966 Astroturf in the AstroDome
• 1967 First outdoor field
• Poligras
• Baspograss
Synthetic Surfaces
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Tennis courts
Indoor sports surfaces
Lawn bowls
In-line skating facilities
Golf courses
Residential lawns
Leisure areas
Preparation of the Field
• Design of a storm water retention
basin
• Tons of soil were removed
• Filter fabric was installed
• Gravel base of 2 feet in thickness
over the entire field
• 0.5 percent grade
Prestige System at JBS
Four layers
A. Polyolefine
fibers
B. SBR rubber
granules
C. Sand layer
D. Polypropylene,
latex, and
styrenebutadiene base
More on Prestige Turf
• “Grass” is 5.5 cm in height
• Rubber granules are postconsumer product from recycled
tires
• Sand locks the grass in place and
provides stability
• Backing is very heavy but flexible
Close Up of Turf
Density of 9,450 tuffs per square meter
Underside of Turf
Drainage holes every 10 cm.
Rubber Granules
0.5 mm to 1.5 mm
A dime is here for comparison.
Football on the New Turf
Notice the Rubber Spray!
Recycling of Tires
Hammermill uses
carbide cutting
teeth to grind tires
into 6-inch or
smaller size pieces.
Grinder #1
More on Recycling
Rotary shear
shredder or hookshear uses heattreated steel alloy
blades for
shredding tires.
Grinder #2
What about the steel belts?
The shredders separate the steel
wire fragments from the steelbelted tires. An in-line magnet
removes the steel from the tire
bits. These grinders can handle up
to 4,000 tires per hour.
What about other uses for
recycled tires?
• Tire derived fuel (TDF)
– Co-mingled with bark and coal to feed
giant boilers in a paper mill
• Crumb rubber
– Used in septic fields, asphalt,
footwear, barrier walls, plastic
lumber, railroad ties
• Landfill acceptance
What about the nylon fibers?
A new patent (March 25, 2003)
developed by USDA has a new
method to recover the nylon fibers
in tires. It describes a “cotton
ginning technology” to save the
nylon for garden hoses, brake
pads, and carpet backing.
Back to the field and track
Mondo Sportflex Super X Track
Track Surface
• Double layer construction
– Bottom layer is a shock absorber
– Top layer for excellent traction
– Vulcanized at the factory to bond the
two layers
– Precut and sent to a site in rolls
– Roll 1, Lane 1 etc.
Mondo Track
Textured top surface
More on the Mondo Track
The base of the track is 4 inches of
asphalt. It must degas and cure
for 30 days before the raw rubber
surface can be applied. This is NOT
recycled rubber. The only
additives are for pigment, UV
protection, and to increase density.
History of Synthetic Tracks
The 1964 Tokyo Games had the last
pre-rubber track for the Olympics.
Mondo tracks were present at:
1976 Montreal
1992 Barcelona
1980 Moscow
1996 Atlanta
1984 Los Angeles 2000 Sydney
1988 Seoul
2004 Athens
Talk with an Engineer
• The field has a warranty of 10
years.
• The track will last 15-20 years. It
can be power scrubbed and
relined.
• Surveyors use embedded metal
plates under the turf to help line
the track.
New JBS Field and Track
(minus the painted lanes!)
Temperature Study
This is a study of
the temperatures
above the surface
and on the surface
during a warm
day in October.
Time to predict the results!
The air temperature was 31.4
degrees Celsius. What was the
surface temperature at the start of
the experiment? ____
What was the change in temperature
at the surface for a 15 minute
study at noon on a warm day? ___
Noon on October 4, 2005
Temperatures of the air and turf
60
50
Temperature in Celcius
40
Air temperature in Celcius
30
Surface Temperature in Celcius
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10
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4
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Tim e in m inutes
10
12
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Data from the
Temperature Study
Air
Start Final
Difference
Temp. Temp.
31.4 C 33.5 C 2.1 C
Turf
52.4 C 55.9 C 3.5 C
Data taken for 15 minutes at noon
Data from the
Temperature Study
Final
Temp. C
Final
Temp. F
Air
33.5 C
92.3 F
Turf
55.9 C
132.6 F
Difference
22.4 C
40.3 F
Heat Study
Measuring
the temps
of water
and turf
under two
100 watt
bulbs.
Heat Study
The turf and water were in identical
plastic containers. The water level
was the same depth as the turf.
The turf had the grass embedded
with sand and rubber granules.
The temperature probes were just
under the surface and they took
readings for 30 min.
Time to predict the results!
The starting temperature of the water
was 21. 2 degrees Celsius and the
starting temperature of the turf was
23.1 degrees Celsius.
Which surface (water or turf) will have
the greater change in temperature after
30 minutes? ___
How many degrees of temperature will be
the difference? ___
Heat Study:
water vs turf
40
35
Temperature in Celcius
30
25
Water Temp. in C
20
Turf Temp. in C
15
10
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Tim e in m inutes
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Heat Study Data
Start
Temp.
Final
Difference
Temp.
Water 21.2 C
23.7 C
2.5 C
Turf
36.6 C
13.5 C
23.1 C
Conclusions from Studies
The artificial turf does get hotter
than the air temperature by a
significant amount.
The artificial turf could be cooled by
spraying water over it before a
game. The wet field also increases
the humidity of the air above the
surface.
More Conclusions
It looks great all the time.
There is some maintenance required
but no seeding and mowing!
The surface is springy.
Players like the soft turf during
tackles but not the spray of rubber
granules.
It is expensive!
Summary
• Students’ interest in chemistry is
increased if they see relevance in where
they live and play.
• Chemistry is all around us. You just
have to know where to look!
Thank you, Mary Harris
mharris@jburroughs.org
www.polymerambassadors.org