In today's manufacturing environment, improving product quality is often part and parcel of broader efforts to achieve continuous improvements. Many manufacturers have opted for a Six-Sigma approach, which can significantly shake up manufacturing and other operational areas, while driving down unnecessary costs.
der Prüfverfahren – z. B. in den Bereichen elektrische Sicherheit,
Beschichtungsdicke und Kühlmittellecks – helfen Geräteherstellern
dabei die Genauigkeit, Flexibilität, Produktivität und Kosten
ihrer Produktion zu verbessern.
appareils électroménagers soumis à des tests rigoureux
progrès réalisés en matière de tests dans des domaines tels
que la sécurité électrique, l'épaisseur du couchage, et les
fuites des produits réfrigérants permet en effet aux constructeurs
de produits électroménagers d'améliorer la qualité et la
flexibilité de leurs produits et d'accroître leur productivité tout
en réduisant leurs coûts.
alle migliorie di collaudo inerenti la sicurezza elettrica,
lo spessore di rivestimento, le perdite di refrigerante,
i produttori di elettrodomestici sono in grado di ottimizzare
la precisione di lavorazione, la flessibilità, la produttività e
For instance, Maytag Corporation uses what it calls a LeanSigma approach in manufacturing.
This identifies ways to eliminate waste in operations, as well as variations
in parts and processes that can undermine product quality. It has been implemented
in a Jackson, TN, U.S. plant, transforming a half-mile long, continuous-line
dishwasher assembly operation. The line was split into seven separate assembly
cells capable of a wide range of product mix capabilities. The effort freed
up 43,000 sq ft of manufacturing space while improving productivity by 22 percent.
Not least of all, it also resulted in a 55-percent improvement in product quality.
appliance companies look at their manufacturing processes, they have a wide
range of testing equipment available to help them meet their goals. Technology
continues to advance, allowing improvements in accuracy, flexibility, record
keeping, ease of use, and even cost.
powder coating, for instance, Tennsco (Dickson, TN, U.S.) has benefited
from using new powder measuring technology. The company makes products
such as shelving, lockers, storage cabinets, filing cabinets, and workbenches.
It has six plants with a combined total of seven powder paint lines and
one e-coat line.
The company decided
to use an Elcometer 550 uncured powder thickness gauge from Rochester
Hills, MI, U.S.-based Elcometer
Inc. "It was first used in plant number five to establish some baseline
settings for the powder booth operators to use as a guide for the proper
booth settings," says
Johnnie Morris, plant manager at plants five and six in Dickson, TN,
U.S. The gauge has since made its way to the other plants running powder
to establish the same settings and look for areas of excess coverage.
The probe, shaped somewhat like a handgun, is positioned about 17 mm (3/4 in) from the surface to be measured. LEDs on the probe and on the front panel of the gauge indicate the position and alignment of the probe relative to the surface. The readings are taken automatically when distance and orientation are correct. The operator then pushes the measurement button again to stop measuring. After approximately 1 sec, the gauge will display the predicted cured powder coating thickness reading.
Corporation (Ogdensburg, NY, U.S.) reports it provides
coating thickness gauges that are advanced, yet easy
to use. This is said to enable a manufacturer to have
the process control it needs without spending money
to learn how to understand the instrument. One model,
the PosiTector 6000 FN, has the ability to measure
coatings on both steel and aluminum with the same probe.
This automatic substrate recognition, the company says,
allows the user to test coating thickness on all metals,
reducing confusion and possible operator error.
Prior to the company's acquisition of the new gauge, cured film measurement
was about the only option available. This meant that the company had
to wait 45 min until the parts left the bake oven. Now, the gauge gives
instant knowledge. "You can make powder adjustments on the fly, rather than waiting 45 min for final confirmation of any adjustments," says
He reports that the gauge works well, and that it required minimal training. With the operating costs for each line, it didn't take too many hours of repaint savings to recoup the investment. That does not even take into account the powder savings incurred by getting the powder setting dialed in correctly much faster than waiting for the first cured parts to become available for inspection.
"We still have a ways to go before I feel we are totally utilizing the one gun we now have, but in time I feel we will probably purchase two more guns so that each of our facilities spraying powder can have access to their own gun," says
engineer tests a power tool using a new combination
tester from electrical safety testing specialist
Clare Instruments Ltd. of Worthing, Sussex, UK. Part
of the company's new range of digital instruments,
the new HAL Combi is said to perform the complete
suite of standard electrical safety tests and allows
full traceability of test results and records via
internal data memory storage. The new tester performs
earth bond, a.c./d.c. hi pot (flash), and insulation
testing to ensure the compatibility of Class II electrical
products with technical and performance standards.
One way to maximize testing efficiency is by combining multiple safety
tests into one workstation. Slaughter
Company (Ardmore, OK, U.S.) says
its enhanced line of hipot testers can be interconnected to its enhanced
line of ground bond testers to form a complete test system that will
do the most commonly performed electrical safety tests - a.c./d.c.
hipot, insulation resistance, and ground bond test.
"This allows these tests to be performed through one connection to the Device Under Test (DUT)," observes Tim Collins, sales coordinator. "Being
able to perform these tests in one DUT connection will increase efficiency.
With one test station and one test connection, products will be moved
through the workstation faster.
"Secondly, one DUT connection will yield more accurate results," he continues. "With
fewer connections, there are fewer chances for a connection to be made
incorrectly. Tests are being performed at the same station, with the
same operator, and the same connections. This reduces possible discrepancies
that could occur if integrated tests were not performed at one test station."
Dwayne Davis, technical services manager at Associated
Research, Inc. (Lake Forest, IL, U.S.), reports seeing more use and integration of multi-function
instruments in production lines. "The main advantage of using multi-function instruments is much more productivity for a manufacturer," he explains. "The
combination of a.c./d.c. hipot, insulation resistance, and ground bond
in a single instrument with one DUT connection will increase throughput
by providing an efficient testing process. Multiple connections to the
DUT are not required."
In addition to multi-function Dielectric Analyzers, customers can also
choose to integrate multiple test instruments with one DUT connection
into a workstation, says Mr. Davis. "This setup is usually chosen because the manufacturer already owns some of the necessary equipment and simply wishes to add more test capability. Although upgrading to a multi-function instrument is still the preferred method, using linked testers can be effective in solving certain test application problems," he
As an example, Mr. Davis tells of a small home appliance producer that has an application requiring a functional run test. This is designed to ensure that the manufactured product will perform its intended functions. This test is normally performed after a hipot test.
"The functional run tester, which the manufacturer developed itself, included its own set of test connections in addition to the test connections of the hipot tester," Mr. Davis explains. "After
the hipot test, the manufacturer would perform the functional run test
without always disconnecting the test leads of the hipot tester. This
caused a failure in its hipot testers when a faulty product was tested
because line power was fed back into the return circuit of the electrical
"The repeated damage to the hipot testers led us to review the application," he continues. "Once
the problem was diagnosed, it was determined that it would be eliminated
by connecting an external functional run tester to the existing electrical
safety testers to allow one DUT connection. This eliminated the connection
issues, as the external functional run tester included an internal switching
matrix. This automatically disconnected the electrical safety tester
before the run test was performed. This manufacturer currently owns several
of our RUNCHEK stand-alone functional run testers. This solution saved
repair costs for the manufacturer while increasing productivity."
Taking the Leak Out
testing is one area where appliance companies may face continued cost pressures
because of increasingly tight leak specifications. "Government regulations for environmental protection and user safety, plus product validation against consumer litigation are driving the specification changes," reports Gary Grebe, marketing director for Cincinnati
Test Systems (Village of Cleves, OH, U.S.). "This
trend makes it more difficult to provide an economical leak test solution
to the customer. The lower leak rate specifications are requiring the
use of more sensitive and more expensive tracer gas technologies like
helium mass spectrometers. These technologies are production-proven and
successfully applied in many industries. But they are more expensive
than the traditional pressure decay and mass flow technologies that are
The CM-2600d portable spectrophotometer from Minolta
Europe GmbH (Langenhagen, Germany) is used to control, match,
and correct color for both finished appliance products and components.
According to the company, the spectrophotometer can be used to ensure
color consistency on any metal or plastic appliance surface, including
glossy, matte, and textured finishes. Common applications include
refrigerators and other white goods, office furniture, computers,
and interior components such as connectors.
The solution, he says, is getting the customer to budget and get approval for the higher expenditures required to meet those specifications.
"In addition, as the appliance producers assimilate the leak test function into their manufacturing line as a process gauge, they want to identify causes for failure so that they can improve their manufacturing process," Mr. Grebe continues. "In
leak testing, that means identifying the leak location. At this time
that requires taking the reject parts out of the manufacturing process
and manually re-testing the part to visually identify the leak and keep
records. Because of the expense of performing this extra manual test,
there has been very little progress in closing this process control loop."
One way appliance producers could reduce their manufacturing costs
is by providing a continuous feedback from their leak test operation
to their assembly operation, Mr. Grebe offers. "This would require leak location identification by the on-line leak test system," he says. "This
need to quantify a part's overall leak rate and simultaneously identify
the leak location has challenged leak test equipment manufacturers for
Testing equipment is increasingly
involved in downloading data into networks. Says Christian Petrilli,
marketing manager for Fischer
Technology, Inc. (Windsor, CT. U.S.), "More and more of the equipment on the production
floors is 'smart' and can be wired into a company's network."
As a result, he says, many
manufacturers capture information in real time to control production
and processes. "When it comes to coating thickness measurement in the appliance industry, instruments are typically used near a paint area, powder coating line, or plating line. This requires rugged hand-held instruments capable of fast, accurate measurements with the capability to download data to a network. Various models are available that feature RS232 interfaces for downloading data to a networked PC. This enables measurements to be taken in the production area, downloaded, and evaluated for process control," Mr.
"Even in today's slow economy when a piece of older test equipment wears out, replacing it with something of current technology is still a viable option for most appliance producers," adds Jim Richards, marketing/applications for QuadTech, Inc. (Maynard, MA, U.S.). "Test
equipment continues to advance by offering more bang for the buck, meaning
it can do more, do it better, faster, and for less money. When purchasing
test equipment, one caution seems to be think beyond the needs of today.
Don't exclude test capabilities, computer interface, or data logging
ability that could become future requirements in the testing process."
Think Fail Safe
Network capabilities are an essential part of one quality trend observed
by Karl Kohlhase, manager of marketing services for ECI (Collierville,
TN, U.S.). "The shipping watchdog guarantees that consumers receive the best quality product manufacturers can provide," Mr. Kohlhase says. "An
all-encompassing cross check through all processes, our PackOut module
is the final assurance that each unit has passed all previous quality
tests. No defect gets through. Electrical interlocks prohibit final packing
and shipping until all tests have been passed. For instance, if the watchdog
detected that a unit bypassed a final leak test, the shrink-wrapping
machine would refuse to work for that serial number. This gives the consumer
a consistent level of quality-guaranteed."
Mr. Kohlhase says that when ECI first introduced the watchdog principle
to its clients, there was some resistance by operators who were concerned
about meeting daily quotas. But as management noticed the significant
drop in warranty claims, it was mandated in no uncertain terms that the
watchdog could not be bypassed. "Our customers have informed us that, with the aid of our Integrated Process Control System (IPCS), they consistently approach zero DOAs (dead on arrivals) and have dramatically reduced warranty claims," he says. "In
one case of a very high-volume manufacturer, prior to installation of
an IPCS, the in-plant reject codes were in the 17 to18 percent range,
and in-field warranty claims were in the 5 to 6 percent range. After
the IPCS was put into place, the in-plant rejects sky-rocketed, and the
field claims basically went down to zero."
As a result, the customer got interested in determining what problems
were causing these in-plant rejects. "With our help it started eliminating problems one by one," explains Mr. Kohlhase. "It
called in its suppliers and talked to them about their component problems.
It also improved the assembly process, the drawings, and other factors
that it found necessary to lower that reject rate.
"As both of these rates (in-plant and in-field rejects) approach zero, your profits will go up," he continues. "Add
greater profits to increased customer satisfaction and goodwill due to
your commitment to quality, and you have a formula for sustained success."