Journal - Trumpf GmbH + Co. KG

sions and damage to the sheet metal, and
reduces the wear at the die itself. Various
swage widths can, in addition, be set up simply
by shifting the jaws. The VLM die is available
in two versions, for maximum load levels
of 1,250 kN/m and 2,000 kN/m.
Initial testing for the die at Kreisel was
promising, but the rollers ultimately proved
to be too soft. The edges of the Hardox
plate scored them. Production manager
Roitsch: “TRUMPF responded to the problem
quickly and with flexibility. We received
— gratis — a new set of rollers that were significantly
harder.”
Savings in many respects
With these “extra tough” rollers, bending progressed
without problems. Not only was wear
minimized, but by working with TRUMPF
engineers and based on the new die, Kreisel
developed a new bending technique in which
the number of bends could be reduced from
five to three. Roitsch notes : “Today we need
only ten minutes per bending cycle, compared
with thirty in the past.”
The VLM die has been in use for about a
year, some 700 plates have been bent so far,
all eight millimeters thick and in lengths of
between 630 and 1,400 millimeters. Machine
operator Maik Lehmann summarizes his
experience at the press brake this way: “We
can shape the plates faster but, in spite of
this, no fissures appear. And we have not yet
seen any wear at the rollers.” Detlef Roitsch
sums up from the business administration
viewpoint: “The VLM die costs a bit more
than a standard die but, the higher price has
quickly amortized itself. You see, processing
Hardox plate has become a unique selling
proposition for us.”
>> abkantwerkzeuge@at.trumpf.com
The Kreisel company was
founded in 1912 as a metalworking
and autogenous welding
shop. In 1972, the company
was nationalized by the East
German government and reorganized
as the VEB Entstaubungstechnik
Krauschwitz, a
part of the State Holding Company
for Ventilation and Refrigeration
Technology in Dresden.
Following German unification,
the company, with its 80
employees, was reprivatized on
July 1, 1992. Today employing a
staff of about 100, the company
manufactures conveyor equipment,
dust extraction equipment,
pressure vessels and heat
exchangers for the construction
materials, foods, chemical, coal,
potassium and glass industries.
Technology: Bending
The rotating, hardened rollers in the VLM die regulate press force and are easy on the material.
The Hardox plates are highly resilient
during bending and have to be “overbent”
by twelve degrees.
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