FORMING & PRESSING CUTTING A DASH WITH LASERS
One of the things that makes these
systems so dynamic is the distance control
for the lasers. This maintains a distance of
0.7 to 0.9 mm from the continuously moving
coil and, where necessary, corrects the
distance within fractions of a second to
ensure that any residual surface irregularities
in the sheet metal do not damage the heads.
Explains Liebel: “This axis is critical to the
line’s output. Each coil contains residual
waves. If I’m looking to blank at a rate of
100 m/min, I need to be able to respond
extremely dynamically.”
Larger surface irregularities are eliminated
by a straightener. “The straightening result is
a key ingredient to a stable process,
especially for the laser blanking line,”
regional sales manager Justine Fonteyne,
offers. “To make this happen, we use the
‘Check2Flat’ system, which adjusts the
crowning on the straightener rollers.” Either
the visualisation system makes a
recommendation based on the adjustment
system, which the operator must then
review, or the straightener itself can even
provide fully automated control. “It’s
important to remove as much of the tension
from the material as possible, so that the
metal doesn’t pop up during blanking. These
types of systems help to ensure process
stability.”
According to Liebel, another increasingly
important aspect for carmakers is the
intelligent capacity utilisation of global
facilities. “It’s dif cult to make a product
somewhere else on short notice if you’re
using a press blanking line. To do so, our
customers rst have to move the die,
prepare it for shipment and then send it off.”
If a supplier is producing the blanks, the
scrap chutes or something else may not t.
“With laser blanking lines in the production
network, all I have to do is send a data set
A shot of the
Decomecc system’s laser
heads in action
for the desired part and make sure that the
coil material is available on-site. If the
system has available capacity, production
can start one or two hours later. It’s really a
huge advantage.”
Fonteyne’s coworker, Berthold Jüttner,
offers another example: “One of our
customer’s plant managers had a problem
with a blanking press and had asked another
plant manager if he would be able to cut a
few blanks for him on the latter’s laser
blanking line. He then immediately sent the
drawings and had the coils brought to the
site. Blanking began the next day.”
In addition to the newly achieved blank
programming freedom, Jüttner sees another
advantage in the line’s excellent dimensional
accuracy, reproducibility and surface quality:
“There are no burrs, and the amount of
cuttings is much less than in conventional
blanking.” The so-called ‘angel’s hair’
phenomenon is especially prevalent where
blanks are cut from aluminium coils and is
also the reason why blanking presses
regularly need to stop, so that the dies can
be cleaned. “This is no longer an issue with
the laser blanking line,” Jüttner adds.
Laser blanking also makes it possible to
support the material across its entire surface
area. “We can nest the parts edge-to-edge on
the coil and no longer need the 8- to 10-mm
dividers required when using the blanking
dies. For small cut-outs, we can brie y open
the belts and the scrap can drop into the
scrap chute.” On the new lines, the scrap
and good parts are no longer separated
using robots, but rather by an intelligent
sorting system. This provides an additional
boost in output.
The growing amount of high-strength
steels used in cars is increasingly pushing
blanking presses closer and closer to their
maximum mechanical loads, Liebel states.
He notes: “When it comes to yield strengths,
there are no limits in laser blanking. We have
performed many tests, and high-strength
steels are no problem.” As Jüttner puts it:
“The laser doesn’t care at all what material is
under it.”
According to Liebel, the bundled beam of
light darts across the metal coil at speeds of
up to 100 m/min at a thickness between
0.7 and 2.5 mm. He adds: “Before the year
2000, it was only possible to achieve
blanking speeds of 4 or 5 m/min using CO2
lasers. Then the bre laser made its
triumphant entrance and opened up the
entire possibility of laser blanking for the rst
time. This development never would have
been possible with conventional gas lasers.”
QUIET, EFFICIENT
A further bene t for laser blanking is that
noise emissions are much lower than with
blanking presses. “If sound protection is
installed on the laser blanking line, you’ll
have to look very carefully to see whether the
line is running or not,” Jüttner says with a
laugh. “You can have a completely normal
conversation, as long as a press isn’t
running next to you.”
The investment cost is also signi cantly
lower, since the laser line is not as tall and
also does not require an elaborate press
foundation, says Jüttner, noting: “That’s a
huge cost factor.” The loop for material
buffer is also routed above ground. The laser
line’s energy requirements are comparable to
those of a press blanking line, however.
Schuler has developed a software
package, LBL Studio. “All you have to do is
upload the drawing data and the program will
calculate the best-possible contours, the
possible nesting options and the optimum
level of laser utilisation,” Fonteyne says.
“After that, the data can be transferred to
the control system and production can be run
exactly as con gured”.
Joint venture effort
Schuler has entered into a partnership with Porsche via the a joint venture company
Smart Press Shop GmbH & Co KG, which will open next year in Germany. Production of
the facility’s laser blanking line has commenced at Schuler. The laser blanking line 2.18
is equipped with two cutting heads for processing strip material up to a width of 1,880
mm. The Smart Press Shop will be located in Halle, North RhineWestphalia, some
10 miles west of Bielefeld, where the production of Porsche aluminium outer skin parts
in small batch sizes takes place.
28 April 2020 | www.machinery.co.uk | MachineryMagazine | @MachineryTweets
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