From a revolutionary idea
proposed and developed by Dr.
Andrew Szegvari in 1945, Attritor
technology grew to become the
basis for Union Process, Inc., an
independent family-owned American
company founded in Akron, Ohio.
Today, Attritors are considered to be the most efficient
grinding/dispersing systems and are used in scores of
industries and research laboratories worldwide.
How Batch Attritors Work
The Attritor is often referred to generically as an
“internally agitated high energy media (ball) mill.” The
operation of an Attritor is simple and effective. The material
to be ground and the grinding media are placed in a
stationary, jacketed tank. This media is spheres 3/32" to
3/8" diameter. Commonly used types are carbon steel,
stainless steel, chrome steel, tungsten carbide, ceramic, or
The material and the media are then agitated by a shaft
with arms, rotating at high speed. This causes the media to
exert both shearing and impact forces on the material,
resulting in optimum size reduction and dispersion.
No premixing is necessary. The material can be directly
fed into the jacketed grinding tank of the Attritor. Those
portions of the formulation requiring only slight grinding can
be easily added later.
Attritors are equipped with specially designed high
starting torque, two-speed electric motors. The high starting
motor means no clutches, etc. are needed. The lower speed
is used for charging and discharging and the high speed is
used for grinding. Depending upon the application,
electricals can be TEFC (totally enclosed fan cooled) or
Production batch Attritors are equipped with a built-in
pumping system that maintains circulation during grinding
for accelerated attrition and uniformity. This pump can also
be used for material discharging. The final result of the
grinding action is a fine, even particle dispersion.
cooling or heating)
can be maintained
due to the use of
water, coolant, oil or
steam systems are
coded tank jackets
may be employed.
action does not take place against the tank walls, wear of
the walls is minimal. In addition, thinner walled tanks mean
that improved heat transfer can be accomplished.
Union Process Batch-Type Production Attritors
Produce Fine, Homogeneous Dispersions
Quickly and Effectively
TANK LININGS—special linings for metal-free grinding are
available. Choose from ceramic (alumina) tiles, food grade
rubber or polyurethane.
ARM SLEEVES—to accommodate metal-free systems, shaft
arms may be sleeved with plastic, tungsten carbide, or
COVERS—can be equipped with a floating shaft seal to
minimize solvent loss, or can be equipped with a MECO shaft
seal for grinding under inert gases, complete with a product
charging port, gas inlet and outlet.
TORQUE METER—for monitoring precise energy consumption
which is used for determining grinding time and for added
DRIVES—variable speed drives (either mechanical or
electronic) are available for conditions requiring the flexibility of
multiple shaft speeds.
STATIONARY ARMS—for reducing tank wear
SPECIALLY CONFIGURED ARMS—for increased agitation and
DSM (Mechanical Alloying)
Metal Powders and
Paints, toners, inks