“The biggest thing right now is the
amount of capital investment, especially in the U.S., in this kind of
line. You’re talking multi-millions of dollars. In order for someone
to justify that process versus foreign labor costs right now, we have
to offer
very flexible lines,” he explains. “If a customer just wanted
to build a random product order group, they literally could. The goal
is to develop systems where there is either little or zero changeover
time
for the customer to achieve that. That is the ultimate justification
right now. The only people that pretty much can afford to do it are the
ones
that are given the highest level of flexibility.”
The obvious question
surfaces: What solutions are available that will make my assembly processes
more flexible and more cost effective? The
answer
to that question, however, isn’t easy: the options are many.
Henkel
Loctite (Rocky Hill, CT, U.S.) offers two patented, industrial-grade,
hand-held
pneumatic spray applicators for dispensing 1.75-in
diam areas with hot-melt adhesives. The Hysol 175-Spray unit
achieves 180°C for dispensing EVA hot melts, while the Hysol
175-Spray HT reaches 195°C for polyamide hot-melt dispensing.
Both 500-W units feature adjustable flow controls to tailor spray
patterns and are said to be ergonomically designed for operator
comfort and application control. In addition, both applicators
feature automatic end-cycle purge to prevent nozzle clogs, a
high melt rate for maximum output, and a fixed-precision thermostat
temperature control for consistent heating. |
|
Getting
Equipped
Appliance makers—especially those with varied product lines—have
much to consider when choosing assembly equipment. Making productive
decisions means carefully reviewing the newest technologies and trends
while keeping
in mind specific applications.
“
The type of manufacturing equipment [available] varies as widely as the
applications do. If you consider appliances to range in size from,
say, electric toothbrushes to refrigerators and dishwashers, you
also cover
a massive range of different manufacturing strategies,” notes
Kevin Gingerich, marketing manager at Bosch
Rexroth, Linear Motion and Assembly
Technologies (Buchanan, MI, U.S.). “In some cases, that might
mean manual assembly stations linked with conveyors; in others, it
might mean
full automation with our turboscara and multi-axis Cartesian robots—or
it might mean a mix of the two.”
Most assembly equipment suppliers
agree that a major trend right now is to offer equipment with increased
intelligence. Smarter equipment
means
less labor, increased productivity, and higher quality.
“
All assembly equipment has improved substantially over the years, as
the needs of manufacturers get fed back into the engineering departments
of capital equipment suppliers. Robots are a great example,” says
Mr. Gingerich. “The turboscara robots we’re selling now
are technological light years ahead of the SCARA robot invented by
Bosch
30 years ago,
and even those sold 10 years ago.”
He explains: “For
example, all programming software is now Windows-based and has
TCP/IP connectivity, so they can even be programmed and tested
via the Internet. Let’s say a customer is installing a
robot in California and is not sure about a certain programming
sequence.
They
can call us
in Michigan, give us the access code to their robot, and we can
troubleshoot their program online. Capabilities like these not
only cut hours or days
out of robot installation, they add convenience and cut costs.”
Mr.
Gingerich adds that many new robots now have absolute encoders
so that the robot always knows where it is in its operating
cycle. “You
don’t
need to ‘re-home’ the robot every time you power
it,” he
says.
Siemens
Dematic offers an
intelligent palette-based conveyor system that utilizes radio frequency
(RF) tags and is said
to allow for
quick changeover
and flexibility. “The pallet (or fixture) contains universal
tooling, where we are perhaps given 10 or 20 products from
the customer that they
would like to build down the same line, and we build the tooling—either
adjustable or very, very quickly changeable—to carry
multiple products,” explains
Mr. O’Nions. The system has several appliance applications,
including range, washing machine, refrigerator, air-conditioner,
furnace, and dryer
production.
“
For example, on a range, we’re carrying anything from single ovens
to very wide double-oven assemblies with cooktops, all on
the same pallet,” says
Mr. O’Nions. “The way we have achieved that is ‘stair-step
tooling,’ where the largest product sits at the highest
level, and the smallest product is at the lowest point of
the stair step. Each
stair
step as you go down the tooling is a different product outline.
So we achieved, in this case, zero changeover time.”
He
adds that the specialty is not so much the mechanical solution,
but the software solution. “We carry intelligence
on the pallet usually in the form of an RF tag that carries
the data for the particular product.
So we might be only carrying a serial number to start off
with, which would be tied to the system. Then we would
automatically
route the pallet to
only the operations that were required for that specific
product. That in itself is nothing revolutionary, it’s
just done on a very large scale, and we tie that in with
recording the test results. With a range,
for example, you measure gas flow, comparisons, electrical
tests, etc. We actually carry the test results on the RF
tag until we get to the end
of the system,” Mr. O’Nions says.
When the appliance
reaches the end of the process, the tag’s information
is downloaded to a host computer system, which records
the results. The advantage, Mr. O’Nions explains,
is that if a manufacturer ever has testing issues or
warranty issues, it has the individual test results of
that particular unit by serial number. In addition, once
the information is downloaded, the RF tag’s memory
is wiped clean and can be used again for the next run.
As
Mr. Gingerich points out, it is important to note that
no one equipment “solution” is
the answer for the entire production line. “The
top consideration for every company is always productivity
because it ties directly to profits:
How do we get the most out of our resources? The answer
will differ at different steps in the manufacturing
process,” he
says. “For
repetitive, high-speed assembly steps, robotics may
be the answer; for more complex assembly sequences
requiring
the flexibility of a human
being, companies may want to undertake time and motion
studies to eliminate wasted
motion wherever possible.”
The Assembly Influence
It’s
no secret that appliance design and production need to go hand in hand
in order to achieve today’s demand for quick turnaround.
While this may require some customization on the
supplier’s part,
OEMs may also find that in order to get the most
cost-effective solution, flexibility needs to go both ways.
“
There’s only a small portion of our appliance products that are
standard. Most of the time we sell a dedicated piece of equipment,” notes
Steve Sawdon, president of BTM
Corp. “We have to consider the shape
of the customer’s part, which depends on
how it is designed.”
Therefore, he says,
it is crucial that manufacturers design their
products with assembly in mind. “Sometimes
we ask them to redesign their products too. That
will help us reduce the tooling cost. We also
provide
them with
flange size and clearance specifications that
we like them to have in order to make lower-cost
machines to join their products.”
Sometimes
the relationship between assembly and design
is so strong that one literally dictates
the other.
An example
of
this, according
to Mr.
Doyon of Schleuniger, is the use of flexible
flat cable (FFC) in appliance design. The cable,
currently
being
used in Europe
for
automotive applications,
also offers major benefits to appliance makers,
he explains. The cable is a light-weight alternative
to round wire,
which makes
it ideal for
portable appliances and consumer electronic
products. It also offers production
advantages. “The appliance industry is
moving toward using more FFC in manufacturing
because it allows for mass termination, which
means
labor
savings, flexibility, and increased quality,” explains
Mr. Doyon. “The
fact that you can mass terminate means that instead
of running, say, 12 individual wires and then
terminating them and putting them in a connector
housing, you basically run one piece and terminate
on both ends and just
plug and play.”
The
holdup, according to Mr. Doyon, is the capital investment
needed to process the cable. “There is a cost up front
to get capability to process FFC. Most appliance makers outsource their
wire harness assemblies,
so as the sub-contractors gain capability in that area, then it won’t
be so cost-prohibitive to start using these new technologies in the appliance
design,” he says.
It
is important to note that the equipment is available, Mr. Doyon adds.
Schleuniger currently offers
FFC Processing
Systems that can be customized
for any application. “What happens is the customer will have an
application, and they’ll send us samples and specs. We’ll
review it, and we’ll build a custom system for their application,
based on standard modules,” he explains. “So, rather than
have to redesign from scratch every time, we know that we need to transport
a flat cable up to
3-in wide. Once we know what the customer’s needs are, we can mount
the individual process stations on the various module, and it all ties
together with a standard software we developed.” Mr. Doyon says that
until appliance OEMs and wire harness suppliers base their decision on
value instead of expense, the industry will have to wait. “Some
OEMs are even saying, ‘We want to use this in our next-generation
design,’ but the wire harness manufacturers will quote a really low
price to do it in the current technology, which is discrete single wires.
So, on paper, it looks cost-prohibitive to the OEMs to jump to that new
technology,” he explains. “But ultimately, there will be
some sub-contractors that make an investment up front, and they will
go out
and look for work. It will happen.” |
