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Potting operation
is smooth and predictable, allowing a single operator to produce four 80-pin
power train connectors every 20 seconds
The perfect computer environment entails a controlled
temperature, an even humidity, and protection from contact and airborne
contaminants. Now, put those same sensitive computer parts under the bonnet of
an automobile. Subject those very delicate parts to wide swings in temperature,
salt, humidity, engine fluids and vibrations, and the duplication of the
perfection of a clean-room environment would seem like an automotive engineer's
worst nightmare.
But it's all in a days work for Augat Automotive, a
leading supplier of precision terminals, fasteners, connectors and assemblies
for automotive applications. In this case, a module consolidates all the
connections between the vehicle's controls and its computer. The module plugs
into the computer, tying all the peripherals to it. Some 80 wires come together
in the plug-in device that becomes the main connection in the computer
network.
Encapsulation of the connectors by something
impervious to assault, obviously, is required. Designing a manufacturing system
to achieve the demanding production rates of 720 connectors per hour and
maintaining the quality was a challenge.
Sealant Equipment & Engineering Inc. (S.E.E.
Inc.) has supplied the meter / mix / dispense equipment for this application to
a number of major automotive OEM's, enabling them to enhance their ability to
meet the increasingly strict quality standards of the Big Three US automakers.
The Augat Automotive application is an example of how encapsulating material
suppliers, automated conveyor system designers, and manufacturers of dispense
equipment can cooperate closely to satisfy the demanding requirements of
customers.
How Important is the
Meter / Mix / Dispense Equipment ?
At the very heart of Augat Automotive's highly
efficient production line lies four
SeeFlo 690® Meter / Mix / Dispense
units made by S.E.E. Inc. Specialising in fully integrated
production systems since 1967, S.E.E.'s potting operation is smooth and
predictable, allowing a single operator to produce four 80-pin power train
connectors every 20 seconds.
A two-component polyurethane material formulated by
Biwax Corporation, is dispensed exactly to the volumetric mix ratio (2:1) by
positive-displacement metering pumps. As the rods are forced into the
displacement metering cylinders, outlet valves open to permit the proportioned
volumes of resin and hardener to flow through to the
Snuf-Bak™
mix-at-the-nozzle dispense valve. There is no dripping or wasted material. A
special SeeFlo No-Flush™ disposable, static mixer nozzle eliminates
the need for solvent flushing…..friendly to the environment and to the
worker. Should production need to be halted for any reason, the nozzle will
automatically purge itself with mixed material after its pot life of 5 minutes
and refresh itself with fresh material, thereby preventing the mixer from
clogging up with hardened material.
The fast-setting material (5 mins / 100 grams) when
cured remains pliable at temperatures as low as -40°C and yet maintains
stability at temperatures of up to +125°C. The viscosity of the material
was formulated to prevent seepage through the connector's pin holes. The A and
B components are fed to the four SeeFlo 690 systems via transfer pumps
that are gravity fed from four 45-gallon drums utilising special "breathers"
and hoses to prevent atmospheric moisture from contacting the polyurethane
material.
Prior to potting, aluminium pallets, containing four
80-pin power train connector assemblies each consisting of two 40-pin chambers,
are loaded onto the conveyor designed by Thermal Innovations. Preheated in an
oven (consisting of medium-wave quartz emitters and aluminised walls for
maximum conductivity), they arrive at S.E.E.'s potting station at approximately
85°C. This preheated stage allows for elimination of any ambient moisture,
improves the flow of the potting material and enhances the polyurethane-to-part
bond.
At the potting station, dispensing may be controlled
manually or automatically. In this application, PLC-based controllers integrate
the meter / mix / dispense equipment with the manufacturing automation.
S.E.E.'s engineered AirDraulic™ power-drive feature ensures a
controlled, constant dispense flow rate.
After potting four connectors simultaneously, the
state-of-the-art conveyor system carries the connectors to the infrared oven
containing short-wave emitters and, again, aluminised walls for greater
efficiency. This oven heats the parts to the precise given temperature
necessary to obtain the proper cure. The pallets then enter a chilled cooling
section where parts reach a temperature of 50°C, low enough for a gloved
worker to remove them from the line and pack them for shipment.
A Win /
Win / Win Solution !!
Increased production efficiency, a minimum of
manpower and high-quality production standards were the objectives of this
project. A space-age potting material, the ingenuity of the oven / conveyor
system designers and customer input have produced a successful manufacturing
process. The heart of the operation will continue to be the contributions of
the meter / mix / dispense operation. Every facet of the process is working
together for a common goal: to manufacture high-quality products for the end
user.
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