Basic HTML Version
14
WORLD FOOTWEAR | JULY/AUGUST 2012
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tools were not usable and that
specialised applications had to be
developed. Shell flattening to go from
3D design on the last to pattern
engineering, size grading, lasting
allowances and stitch notches were
part of shoe jargon; they had no place
in any general purpose CAD system.
That pushed a group of software
developers, both large and small with a
solid background in shoemaking, to
develop the first families of specialist
shoe CAD applications. Some are still
in business, others failed and have
disappeared. Specialist shoe CAD
systems, however, whether the simpler
2D or more complex 3D versions, are
now used in virtually all shoe design
departments in the world. The way
they work mimics very closely each
step of the typical design process,
including drawing style lines on the
shell, flattening the shell and
separating each individual part of the
upper. So, in a way, there is no true
revolution in this approach. The real
change is the shift from the analogue
to the digital world, in the wealth of
information a complete CAD model of
the shoe affords, the ability of the
designer to control it and the
manufacturing potential it contains.
CAD designers can also work faster,
do more and control much more of
the manufacturing process than with
the classic manual approach. This
was a major step forward and a
change of mindset that taught them to
anticipate manufacturing decisions at
the design stage and to predict the
impact of design choices on
downstream processes.
DIE-LESS CUTTING
Both the revolution in last making
and the one in shoe design were
enabled by digital technologies.
Software to model the last and design
the shoe and numerical controls to
drive the new generation of milling
machines, originate in the domain of
the so called IT world which was
rapidly developing in the years when
these innovations were introduced. It
is therefore no surprise that the next
revolution shares the same roots.
In this case the trigger was different
and
relates
more
to
the
transformations the shoe industry was
undergoing two decades ago than to
the availability of the appropriate
enabling technologies. At that time
shoemaking began to change;
production quantities, especially in
more industrialised countries, were
shrinking under competition from low
labour cost nations. Flexibility,
versatility and rapid market response
began to matter more than production
efficiency and pure throughput.
Shoemaking starts with cutting all the
necessary components out of the
different materials the product is made
from. No surprise then if the first
technology to be revised in light of this
structural change was cutting.
Whilst the problem was quickly
identified, a complete solution took
longer to achieve. Smaller production
volumes made it increasingly difficult to
justify the cost of the knives traditionally
with the clicking presses then in use
and called for an alternative system that
could do without them. This led to the
development of a new class of shoe
machine, now commonly known as NC
die-less cutting systems, that have in
time replaced traditional knife cutting,
initially in sample making and then in
bulk production.
CAD for shoe design
CREDIT: CSM3D AND INESCOP
Dieless cutting machine.
CREDIT: ATOM