| What
may well be recognised as the single most significant weapon
in the fight against 2,4,6-trichloroanisole (TCA) in cork began
by reference to the compound's basic chemistry.
The ROSA process was built on
the simple premise that steam could be used to extract TCA
from contaminated cork. Over three years and tens of thousands
of tests later, the ROSA process is now being used commercially
to successfully treat cork granules used in Amorim's Twin
Top® and Neutrocork® products. Its development for
stoppers and discs is proceeding at a good pace.
The road in between has been
long and laboured, with some major engineering obstacles overcome
along the way.
According to Amorim's head of
research and development, Professor Miguel Cabral, it has
long been known that TCA is steam-volatile but the possibility
of using this to combat TCA in cork had been overlooked.
"We were very excited by
the possibilities,and even more so with the results of our
initial laboratory tests.We were convinced we had the answer,"
he said.
However, while the research was
relatively straightforward, the development-proving the process
at an industrial scale-has been much more complex.
One early challenge was to achieve
consistent reductions in TCA levels. Another was to avoid
recontamination due to condensation within the ROSA chamber.
"We found several key variables,
including water flow and temperature of the steam, influenced
the effectiveness of the process," Prof. Cabral said.
"Once we got the balance right we were able to achieve
consistently large reductions in TCA contamination."
A further challenge, which affects
ROSA's application to discs and stoppers, is the impact the
process has on the physical properties and visual appearance
of the cork. This has emerged at the semi-industrial scale.
The application of ROSA is more
effective at very high temperatures,but an increase in temperature
has a greater physical impact on the cork.
The problem has been solved,
in part, by moving to a batch system rather than a continuous
line process in applying ROSA to disks and whole stoppers.
At present, the Amorim team is
working on steam flow adjustments to achieve the optimum result.
"Our goal is to extract
any volatile compounds that are present including TCA, but
we need to do this in a way that does not affect the integrity
of the cork," Prof.Cabral said.
"We also need to do this
cost-effectively. Of course, we can rectify physical deformation,
but we would rather avoid having to so we can keep costs down.
"We are confident that further
development of the ROSA process will overcome most of the
remaining challenges.
"It is important to realise,
however, that ROSA is only one part of Amorim's overall strategy
to improve the quality of our products. Prof.Cabral said one
of the greatest moments for his team-which comprises Dr. Stephan
Dahl and Isabel Roseira-in the three-year development of ROSA
came when the Amorim board recognised the potential of the
new process and committed millions of dollars to bringing
ROSA-treated products to the market.
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