PLANNING AND PRODUCTIVITY
Manufacturing Process
Improvement
Background
Advent Design was asked by a local
manufacturer of moisture analyzers to review a manufacturing process
for the analytical cell which was the central component of their
analyzers. Process yields had been very low, falling into the
single digits at times, and the material used in the cells was
very expensive, high purity precious metal wire. As a result,
scrap and re-work costs were very high, and the overall output
and productivity were quite low resulting in long lead times for
the analyzers.
Project Description
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Advent
Design reviewed current process documentation, observed
assembly operations, and analyzed production data in order
to develop an overall picture of the cell manufacturing
process and operation. The high failure rate was traced
to two main areas, wire embrittlement and glass cracking.
The wire embrittlement prevented the sleeved and sealed
cell element from having its wires peeled back to allow
for connection to the electrical contact posts for the cell
or from having the wires wound around the contact posts.
This failure mode was traced to a combination of the processing
and handling of the wire during the cell production process
and the manufacturing of the wire. Meetings were held with
the wire manufacturer to improve and stabilize the wire
characteristics to better suit the client’s manufacturing
process. To assist in this matter, enhanced quality control
measures were developed and put into place to provide the
data necessary to check, evaluate, and improve the wire
characteristics.
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The glass cracking seemed to be the result
of stress induced in the glass sleeve as it was sealed.
For this problem, the corrective action focused on the development
of an improved sealing method using a tube furnace where
the glass sleeve for the cell element could be sealed all
at once. The original method used a moving heater, which
sealed the sleeve about _” at a time and which seemed
to induce great stress on the ends of the glass sleeves
where the glass flowed the most. The results from initial
work with the tube furnace was quite promising, and through
some additional experimentation, a new method for the sealing
process was developed.
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Impact
Once the wire characteristics
were improved and the new sealing procedure in use, production
yields rose above 80% on a consistent basis and frequently exceeds
90% now. Based on the remarkable results, Advent Design has worked
with the customer to review other production areas and to start
implementing lean manufacturing processes within their facility.
Three value stream maps were developed by working with the company’s
manufacturing team.
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