75 years of Egokiefer: Tradition and Innovation

Steel Technology
Drawn profiles:
from the idea to the product
The sheet metal door profile 735.906/T was announced at BAU 2007 in Munich and attracted
considerable interest. The successful profile went from idea to manufacture in an exciting manner.
At the start there is a clever idea from development at Forster
Profile Systems inspired by market analyses and customer
surveys. The idea is «refined», sketched and reaches tool
making. There the tube to be used is defined and the tools
drawn. The tools are then manufactured, the tubes to be
used welded, and the profiles drawn. The profiles are then
assembled and used to make doors. Sounds simple you could
think. The actual route from the idea to the finished door is
somewhat more complicated:
When practice contradicts theory
The starting point is a finished profile shape from which
a tool sequence is defined for the manufacturing process.
For a complex shape, the steel tube used passes through
several stations until the final profile is complete. The individual
forming steps must be exactly matched to each other.
Then the exact manufacturing process is defined and the
prototypes manufactured. During this activity, theory and
practice may drift apart. In the case of this specific project,
there were problems with the drawing tip during prototype
manufacture. The tips must be matched to the drawing tool
due to the reduction in the cross-section of the profile shape
produced. The compressed materials cannot, of course, be
moved so easily through complex drawing dies. The tips must
be cut in sequence. If too much is cut away, although the entire
piece may pass through the drawing tool the remaining
tip cross-section is insufficient to adsorb the drawing force:
the tip is torn off.
Finished tools for the profile.
The finished, assembled profile.
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Challenges with learning effect
Other difficulties arose with the point loads on the ribs, that is
the term used for the inserts in the drawing tool used to form
grooves or recesses. As a consequence, these ribs broke off
and had to be re-designed. Entry angles were changed, rounding
radii adjusted – and then everything worked. Of course,
such changes cost time. However, they also provide a significant
learning effect for subsequent development work. «