RESOURCE UTILIZATION ALTERNATIVES FOR SCRAP TIRES
Terry A. Gray, Market Development Manager
Hydroscience, Inc.
Midland, Michigan 48640
Dimitri Jeon, Manager of Business Development
Hydroscience, Inc.
Emerson, New Jersey 07630
INTRODUCTION
The evolution of worn or scrap tires could probably be traced back to the invention
of its basic great grandfather, the wheel. Our population growth, industrialization, transportation needs, highway systems, and general affluence have culminated in the current
generation of about 200 million worn tires per year in the U.S. alone[l]. But applications for worn tires have not evolved as rapidly as their generation, resulting in an increasing number of seemingly useless scrap tires. As this number has increased, so have the
problems associated with their disposal.
The objective of this discussion is to provide a brief historical perspective, review some
current trends and uses, discuss some of the short- and long-term alternatives, and provide
a simplified, flexible economic framework for your future consideration of several
alternatives.
HISTORICAL PERSPECTIVE
Early natural rubber tires were recognized as an economically attractive resource and
were reclaimed for other constructive purposes.   The development of synthetic elastomers
and complex formulations have dramatically improved tire life and safety.   However, it
has also complicated the reclamation process and limited the markets for composite
reclaim products.   As a result, economic attractiveness has been diminished.   Less than
7% of the scrap tires are currently reclaimed, and this percentage has been steadily
decreasing [ 1 ].
The evolution of stronger tire bodies permitted recycle of some casings for reuse
through retreading operations.   This is a mature industry currently utilizing less than
20% of the worn tires.   It has been most effectively utilized for truck, bus, and off-the-
road tire life extension where tire body control by fleets is easiest and economics are
most compelling.   The public apparently considers retreaded tires to be inferior, possibly
because we are conscious of the abuse we give the tire carcass in its initial use.   The
economic differences are often not considered compelling.   As a result, the percentage
of worn tires used by this industry has been declining and probably will continue to do
so unless availability of new tires or economic differences unexpectedly change
significantly.
There are also a number of smaller uses like door mats, dock bumpers, and many
others using split tires and some ingenious uses for whole tires in landscaping and recreation, but we can only construct so many children's swings.   Totally these uses account
for less than 2% of the worn tires and even a significant percentage growth would not
have a major impact on the problem.
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