TPT July 2011

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40 July 2011 ›
Technology Update
TROESTER GmbH & Co KG and Sikora AG
have presented a new technological concept
for quality assurance using an automatic
wall thickness centring for the production of
rubber hoses in the extrusion process.
The basis of the new system is an
automatic tool centring developed from
Troester in combination with Sikora’s
X-Ray measuring technology X-RAY 6000.
With the use of these technologies the
manual centring effort during production is
considerably facilitated. Furthermore, this
online concept continuously assures an
optimum hose centring and thus uniform
wall thickness distribution over the complete
hose circumference.
The basis of the new Troester system
is an optimised crosshead, which allows
an extremely precise adjustment of the
inner tool (mandrel tip) until the tool is
perfectly centred. This is achieved by an
automatic hydraulic servo-system. The
new crosshead receives the information
for precise tool centring via the Sikora
X-ray measuring device X-RAY 6000. The
system continuously measures online the
wall thickness and eccentricity of the hose.
The measuring values are transmitted to
an optimised PID-controller, which adjusts
the eccentricity of the hose automatically
within a split of a second with an impressive
precision. Among all tested production
conditions the X-RAY 6000 achieves an
eccentricity per axis of below one hundredth
of a millimetre and maintains this value
over the complete production time. “Via
manual centring such a precision can only
be achieved with tremendous effort and
is hard to maintain over a long period,”
explains Peter Hügen, area sales manager
at Sikora. Besides the high accuracy,
which assures the continuous and precise
collection of measuring values, the system
has a selectable measuring rate of 1 to
3Hz (optional 10, 100Hz). The device is
equipped with XLL (eXtra-Long-Life)-X-ray
tubes that guarantee high reliability and
life time.
An important criterion for the success of
the system is the distance between head and
measuring device. In practice this means for
example a distance of ca. 20cm between
the die piece and measuring centre. “The
distance should be as short as possible
under consideration of the line speed,”
explains Peter Hügen. “On average, there
are five to seven control steps necessary in
order to, for example, control an eccentricity
from 0.6 to 0 respectively 0.01, that is
to produce the perfect hose,” added Mr
Hügen. A control step is the time span that
is required to get from the head output to
the measuring point. Generally, it takes one
to two seconds until the next control step
is started.
With the new automatic technology
concept the product quality can be increased
with the help of a stable online control
process. An additional advantage: due to the
permanently assured precision the customer
can reduce a bit from the safety of wall
thickness that means, to work with nominal
values – without oversize. Calculated upon
one year this leads to significant material
savings. Thus, an investment in the new
crosshead with integrated X-ray measuring
technology amortises within one year.
Sikora AG – Germany
Fax: +49 421 48900 90
Email:
Website:
Technology co-operation between
Troester and Sikora on extrusion process
Handrails
angled tube
drilling
DRILLING tubes in angle, handrails
flowdrilling and threading, balustrades
inclined drilling, shelves systems tubes
drilling, boring radiators and other tubular
stainless steel constructions has always
been a difficult job whenever using vertical
drilling or milling machines.
Drilling long tubes, getting a good
alignment of the two holes of the drill and
making drills in an angle is time consuming,
difficult or even impossible to perform with
conventional equipment.
TDM2 tube drilling machine allows
straight and angled drilling up to 30 degrees
on the two sides of the tube at the same
time. Tapping, flowdrilling and threading is
also possible in the same machine, drilling
tubes quickly and accurately.
Tests made with stainless steel handrails
and stairs companies show increases
in productivity rates from one drill in
conventional machinery to 8 drills (12 holes)
in TDM2. Savings are also obvious due to
the tool’s durability.
By using the flowdrill option up to M10,
a thicker tube wall is immediately created
and, in the same operation, with a simple
and guided tube rotation, TDM2 performs
the threading. This simple task often
replaces welding once it makes the fixation
of stainless steel cables much easier.
NS–Máquinas Industriais – Portugal
Email:
Website:
The new technology concept from Troester
and Sikora for quality assurance with
automatic wall thickness centring