ogy applications and material end uses under
certain conditions. To develop the original
manual, CWC convened technical experts
across the nation in a twoday meeting to iden-
tify the technology and research needs of the
industry, potential sources of best practices
and potential best practices. The resulting
manual has 39 best practices divided
into the
following headings and sub-headings:
Sourcing
F rom processing to end use, the steps
in tire recycling can be improved
with proven techniques.
I
Processing
- safety
- quality assurance
- size reductiordgranulation
- materials preparation
Product manufacturing
- manufacturing systems
- quality assurance
- compounding
Direct end-use applications.
Most of the best practices are presented in
quick, two-page summaries that provide in-
formation on the issue addressed, a descrip-
tion of the best practice, suggestions for im-
plementing the practice, the benefits, sites
where the practice has or can be implement-
ed and references for additional information.
We summarize selected best practices be-
low.
Grinding equipment selection
Best Practice BP-72-03-02 addresses the is-
sue of reducing the size
of the rubber article
to particles of 10 to 200 mesh
in order to pro-
duce a crumb rubber. The first step is pro-
ducing granulated or coarse-ground rubber.
Eight types of equipment in three general
groups are used for cutting or grinding. Knife
hogs, primary granulators, secondary granu-
lators and raspers operate
on the same basic
principle, but have different knife configura-
tions. They are classified as medium- to high-
speed, 100 to 1,200 revolutions per minute
(rpm). Knives attached to a rotor
fly close by
stationary knives, causing a cutting and shear-
ing action. The product size is controlled
by
a screen within the machine.
The second group of machines -
prima-
ry crackermills, se