GHM edia
B usiness
Case Study
3D Printed sewer cleaning nozzles
I
t takes four steps to make a conventional sewer cleaning
nozzle – cut, turn, mill, and glue the material. The high-
tech company TRUMPF recently joined forces with the
nozzle manufacturer USB Düsen and the Heilbronn University
of Applied Sciences to expedite the process with additive
manufacturing (AM) and optimize components. Their efforts
paid off: USB Düsen’s machine availability is up 53 percent
and the water jet’s guidance has improved. TRUMPF experts
also expect these nozzles to do a better job of cleaning using
less water.
To clean large sewer lines, workers plug a hose into vehicle-
mounted machine, at the end of which is a ‘bomb’ or
‘grenade’ that slides down channels on a carriage. The head
of the bomb is fitted with 12 to 15 nozzles that spray water.
These jets hit channel walls at pressure levels up to 300 bar to
blast away the sludge, which is then sucked into the vehicle
via the hose.
Conventional nozzle manufacturing is time-
consuming
The nozzles’ design is simple, but it still takes four steps to
30 | january-february 2019 |
Global
MDA
manufacture these attachments. The first is to cut the raw
material – in this case, stainless steel – and then thread it on
a lathe to create what is in effect a massive bolt. Then two
blanks are placed in a milling machine to cut the contours of
a nut into the front face. Finally, a worker glues in a ceramic
insert by hand. “The operator has to remove the component
from the machine for each step. What’s more, gluing often
leaves imperfections that change the jet’s guidance,” says
Fatih Arikcan, additive manufacturing application engineer
at TRUMPF, with a note of disapproval. TRUMPF decided to
go with additive manufacturing to cut production time while
boosting cleaning performance.
Hybrid process chain for big savings
Its experts took a hybrid approach for the new nozzles,
combining conventional and additive processes. They stuck
with the lathe for the massive threaded base component,
which is called a preform. “This process is solid. AM doesn’t
add any value here. On the contrary, the process would end
up taking longer,” says Arikcan. The 3D printer is to perform
the following steps, milling and gluing. TRUMPF opted for
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