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A Massachusetts manufacturer of complete operating room packs
meets the strictest medical instrument specifications by performing
in-house all operations necessary to deliver procedure packs “ready
for the operating room.” To achieve total in-house control
over all operations, the manufacturer machines the raw stock,
does laser welding as required, labels the instruments, manufactures
the instrument packages, and assembles the instruments in the
procedure packs. This approach to the market requires developing
a diverse range of manufacturing expertise and capabilities, and
also demands the ability to make quick changes on the fly throughout
the process whenever a customer changes delivery schedules or
product requirements.
To stay abreast of this dynamic production situation, they run
a two shift 20 hour operation, and lost production time is not
tolerable. Unfortunately, they experienced frequent unscheduled
machine downtime as a result of plugging in the coolant delivery
lines of two new vertical machining centers, which are equipped
with 3/4” to 1/4” lines to feed the through-the-spindle
coolant and five coolant nozzles. Loss of coolant flow automatically
shuts down the machines, which often run unattended. The coolant
line plugging problem was particularly troublesome when machining
titanium because the light titanium fines, which float in the
sump, are picked up by the coolant pump and pumped into the spindle
and coolant nozzle lines. Maintenance found that about every two
weeks the fines would pack into the coolant delivery lines and
back up 12” from the discharge nozzles and spindle. It was
then necessary to shut down the machine, pull off all the nozzles
and bellows covers and clean the lines. This operation is performed
by a man in a cramped space in the machine for 3 to 4 hours, obviously
not a popular job for the machine operator. More important for
management, each of the two machine tools was off-line for 3 to
4 hours every two weeks, when every production hour was urgently
needed.
The shop maintenance supervisor recognized that it should be
possible to alleviate or even eliminate the plugging problem by
filtering out the solids downstream from the pump, before the
line splits into the coolant distribution manifold. Since he was
quite satisfied with the performance of two portable pump/separator
units to remove tramp oil from the coolant he had previously purchased
from Keller Products (Acton MA), he decided to contact Keller
for a possible solution to the coolant line plugging problem.
The Keller salesman immediately recommended the Model XS075–2130
stainless steel and brass filter housing containing a 100 micron
Keller permanent cleanable filter element. The rugged housing,
about 4” diameter by 14” high with 3/4” inlet and
outlet ports, is easily installed by the shop in the coolant delivery
line. The Keller proprietary permanent filter element, which fits
all standard cartridge filter housings, has a much higher flow
rate at low pressure drop than a similar size disposable filter
element. The cleanable filter element is constructed of thin plastic
discs with precisely sized grooves, mounted on a plastic core.
The large internal filter surface area provides excellent solids
holding capacity and long runs between cleanings. When cleaning
is required, the element is removed from the housing, and the
discs separate to a stop on the core. The all-plastic element
can then be cleaned in a bucket of water, by washing with a hose,
or in a parts cleaner. Any shop cleaning agent or solvent can
be used. The Keller filters with permanent elements, available
in ratings from 40 mesh to 300 mesh (50 micron) and flow rates
to 150 gallons per minute, are ideal for any through-the-spindle
or through-the-tool applications.
The XS075–2130 assemblies were installed in the coolant
line on each of the two machines. A spare cleanable filter element
was purchased for each filter housing. The result: the coolant
line plugging problems have completely disappeared, the 3 to 4
hours of unscheduled downtime per machine every two weeks have
been eliminated, and the machines can run unattended without danger
of shutdown because of loss of coolant flow. The only filter maintenance
required is to remove the dirty filter element and replace it
with the clean standby element once every two weeks, a task of
about 5 minutes. The dirty element is then cleaned and stored
for the next cycle. The maintenance supervisor says, “The
Keller filters completely eliminated unacceptable machine downtime,
and the machines are now running at maximum productivity. The
filters are relatively inexpensive and were easy to install. The
Keller filters are a simple solution to a difficult production
problem.”
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