of cost, quality and strength. The same
exercise was carried out for the material
of the separation platform, resulting in the
selection of aluminium as affording the
best balance of cost, strength and weight.
THE ‘X’ FACTOR
The next exercise carried out was Design
for X. The ‘X’ in this case was taken to be
manufacturability and assembly, quality,
flexibility and inspection, as discussed
with Toly. Finally, a failure mode and
effects analysis was carried out to
anticipate potential failures and mitigate
them. In order to prove the working
principle of the separation process,
several fully functioning Lego models
were created, implementing pneumatics
and conveyor belts.
A random sample of unseparated
mirrors was obtained to test the model.
Despite the low-powered pneumatics
and plastic construction, the model
succeeded in breaking the mirror and
avoiding any defects in all the separation
movements. The Lego model was then
used as a basis for the layout of the
dimensionally accurate CAD model.
Succesful separation of a scored
glass mirror, defect-free.
EVALUATION & DISCUSSION
A cost exercise was carried out, proving
that the new automated system would be
cheaper in the long run than the current
manual method. This was done by showing
that the full parts and assembly costs
would be within a payback period of roughly
two years, which is the standard acceptable
to Toly. The result of the calculations
revealed a payback period of 1.42 years.
A new generation of highly durable titanium implants is being
mooted, with patient trials commencing in as little as four years
Running costs were then considered
regarding all the moving parts and heating
elements, revealing an energy cost of €310
euro per year. Next, waste separation was
looked at, suggesting a potential redesign
of the removal arms, in order to improve
the accuracy and reduce chipping of the
mirror surface.
A comparison of manual and
automated movements was compiled.
After analysis, it was established that
it takes two trained and experienced
workers an average of 45 seconds
to process 88 mirrors. The proposed
automated solution takes 57 seconds,
while also incorporating the heat
treatment zone and thus reducing
breakages. In one hour, it is projected
MIRROR, MIRROR
that the machine can process a minimum
of 5,280 mirrors, satisfying the PDS
established earlier. This is because
there is a constant flow of mirrors being
separated, unlike the manual method
which processes a sheet at a time.
SWOT ANALYSIS
A SWOT analysis was carried out, which
revealed that the proposed design
solution is a simple and straightforward
approach to a complex problem, while
being low-cost and manufacturable,
cheap to run and truly universal in
design. Weaknesses identified were the
initial teething problems, as it is a new
type of machine that requires precision
movements and training of operators to
run efficiently.
Opportunities for this project include the
fact that it is an original separation method
that could belong to Toly, applicable to the
cutting of glass as well as mirrors. Other
ceramics also would have success with this
separation method.
Threats to the success of this project
is the unknown aspect, in particular how
production-level speeds could impact the
quality of the mirror. Future work on this
involves the full automation of the mirrorcutting
process, which would require a vast
overhaul of the industry.
ACKNOWLEDGEMENTS
David Sciberras extends his thanks and
gratitude to project supervisor Dr Philip
Farrugia, “a firm, patient and helpful hand
that guided me to academic success”. Dr
Farrugia is IED Malta Regional Coordinator
and a senior lecturer at the University
of Malta. Industrial insight was provided
by Karl Farrugia and Olaf Zahra from
Toly Malta, both of whom were said to
be “invaluable in their input” throughout
the development of this project. “My
appreciation must also be shown for Toly’s
Mirror Department and all the staff who
were always cooperative and happy to
answer any queries I had.”
References:
1. Roozenburg, N. and Eekels, J. (1995)
Product Design: Fundamentals and
Methods, Chichester: Wiley, 1995, pp.
84-93.
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