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 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 hood 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 day’s work for Augat Automotive (acquired by
Thomas & Betts), 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, trying 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 the
challenge.
Sealant Equipment and Engineering, Inc. (S.E.E.),
Plymouth, MI ., has supplied the meter/mix/dispense equipment
for this application to a number of major automotive OEMs,
enabling them to enhance their ability to meet the increasingly
strict quality standards of the Big Three 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 high efficient
production line lies four SEE-FLO 690 meter/mix/Dispense units
made by S.E.E., Inc. Specializing 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 Corp.,
Des Plaines, Ill., 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 SEE-FLO 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 of mixed material after
its potting life of five minutes and refresh itself with new
material.
The fast-setting material (5 min./100 grams) when cured remains
pliable at temperatures as low as -40C 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 SEE-FLO 690 systems via transfer pumps that are gravity fed
from four 55-gallon drums utilizing special “breathers” and
hoses to prevent atmospheric moisture from contacting the
polyurethane material.
Prior to potting, aluminum pallets, containing four 80-pin power
train connector assemblies each consisting of two 40-pin
chambers, are loaded onto the conveyor. Preheated in an oven
(consisting of medium-wave quartz emitters and aluminized walls
for maximum conductivity), they arrive at S.E.E.’s potting
station at approximately 185°F. 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,
aluminized 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 125°F, 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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