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of Desma, explains: “The more manual steps performed, the
more chances there are for inaccuracies and, in the footwear
world, inaccuracy sooner or later leads to a drop in reliable
quality.” The concept is already proving itself in everyday
manufacture. HKS (Heinrich Klumpen Sons) produces
premium safety shoes. This market sector in Europe is tough
and demanding, so its 80-strong workforce at Nettetal in
Germany has to develop and manufacture footwear which is
consistently able to meet these demands. The company
regards its new Laser Cell as a valuable investment which
will help it to meet that goal in terms of both output and
quality.
SMALL AUTOMATION
Italian machinery company Main Group has also
developed automated systems to save on labour costs while
at the same time improving end product quality on its
injection moulding machines. It refers to these as ‘small
automation’. For instance, an injection moulding machine
cannot be considered an end in itself but must be seen as an
integral part of a complete production process. In this way,
the adoption of automated systems, however small, can
contribute significantly. Small but important tasks carried out
manually can be performed better by automated equipment.
A good example is sprue-pulling on the Delta 900 machine
for the production of TPR boots. It is a simple repetitive task
which nevertheless costs a remarkable amount of lost time
and is easily replaced by a robotic arm. The moulding
machine’s software program is able to accurately monitor the
position and time when the robot needs to perform the task.
This is normally just after the injection phase due to the
cooling and solidification of the material located in the
injection gate inside the mould.
Another simple repetitive task on the same machine is
slipping the boots at the end of the moulding cycle. In this
instance, timing is particularly crucial as they must be
removed as soon as possible once the mould has opened.
This is where a robot really scores over a human operator
liable to fatigue in the course of a long working shift as the
program activates it to the very second, time after time. Other
associated applications include general handling, mould
release spraying and component insertion. All these minor
operations as well as the major ones of the moulding
machine itself are managed by a ‘single thinking head’ from
which the efficiency of the whole plant results.
The special software used not only controls actual
functions but constantly detects and monitors any
irregularities allowing a clear overall picture to be seen of
everything occurring during each working shift. For example,
machine speed and output reports reveal the actual time the
machine has been working and how many rejects it has
produced by type so that corrections can be made with a
minimum of delay. The ‘moulding plant’ can in fact operate
and produce complete boots without any manual
intervention by the operator.
Like Desma, Main Group also sees automation as the way
to save manpower which, in Western economies, greatly
affects the price of the finished product. The company says
that the advances it has made in this area in regard to
machines such as the Delta 900 has enabled some major
brands to bring production of TPR boots back to Europe from
Asia. While these are relatively easy footwear products to
automate, it is nevertheless a pointer to what may begin to
happen on a wider scale.
CONVENTIONAL FOOTWEAR
The developments we have looked at so far suffer from
limitations as to the type footwear that can be produced.
These are essentially industrial and safety shoes, some types
of sports and comfort shoes and complete moulded boots in
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TURNING FULL CIRCLE
SEPTEMBER/OCTOBER 2012 | www.footwearbiz.com
Automated boot removal on the DELTA 900 rotary machine.
CREDIT: MAIN GROUP TECHNOLOGIES