A Less Hazardous Lubricant. “While
many of our systems still use the high-
output grease pump to force gel through
the mandrel, this microlubrication sys-
tem definitely serves those customers
who don’t require the gel,” said Will
Winn, sales engineer for Horn. “Initially
we thought it would be a good applica-
tion for tube benders in the HVAC indus-
try, but that’s not all. It’s a good option
for any company that needs to powder-
coat the product after bending. Many
lubricants flash and can start a fire if sub-
jected to too much heat, so they have to
be washed off before the tube goes
through the powder-coating process.
The Metalloid product virtually elimi-
nates the need to wash the tube prior to
powder coating.”
Because the lubricant is based on a
vegetable oil, it complies with some of
the requirements for specific applica-
tions and industries.
“It’s ideal for bending copper, any tu-
bular product associated with the input
to a compressor, and food processing
applications,” Winn said. “The lubricant
has to be inert so it doesn’t damage the
compressor, and vegetable oils meet this
requirement.”
Less Cleaning, More Bending. In addition to pushing the lubricant through the
mandrel, common application methods
include squirt bottles and rags doused in
oil. Such practices are rarely consistent.
Too little lubricant leads to scratches
and, in severe cases, galling. Too much
lubricant is a matter of wasting lubricant
and wasting a lot of time removing the
excess lubricant.
“When making boiler tubes and similar serpentine products that consist of a
series of 180-degree bends, it’s not very
easy to get the lubricant out of the tube,”
Wiedemann said. “The machine operator unloads the machine and hangs the
tube on a rack to let it drain.” That’s one
extra step and the time it takes to drain
the tube. Even when using a tube washing system, getting rid of the lubricant
can take more time than it really should.
“Many fabricators use a machine
to wash off the lubricant,” Wiedemann
said. “Depending on the amount of ex-
cess lubricant on the tube and the effi-
ciency of the process, the machine might
need two or three cycles to eliminate all
of the lubricant.”
Just getting the tube from the
machine to the washing system can be
problematic.
“I know of one shop that relied on its
machine operators to tilt the tube and
pour the excess lubricant into a bucket
right after the tube came off the bender, “Wiedemann said. A low-viscosity,
water-based fluid, it didn’t stay in the
bucket—quite a bit of it missed the
bucket altogether or splashed onto the
floor, which then had to be mopped, he
explained.
“They were mopping that floor three
or four times per shift,” Wiedemann said.
“Who wants to pay a machine operator
to mop a floor? The time spent mopping
could be used for bending.”
How It Works
The microlubrication system uses a stack
of positive-displacement pumps, each
one delivering fluid to a specific area.
Its configuration for tube bending machines uses a single pump for mandrel
lubrication, which delivers fluid through
Figure 1
A common configuration for a microlubrication system consists of a control unit with reservoir, a pump, and a solenoid. It dispenses a
specifically metered quantity of oil to the mandrel and an oil mist to the dies.
