Surface World July 2019 Surface World July 2019 | Page 178

BANNER CHEMICALS
Throughout the strife of the regulated years there
has been an energetic drive, somewhat equivalent
to that of the “Gold Rush” prospectors of the late
19th century, where companies have striven and
raced to find the “Wonderclean” product that will
capture the chlorinated business from the potential
competition. Although this sounds aggressive, and
in some cases it could have been close to that,
it actually led to a great deal of technological
advancement. There was a lot of hard work and
costly investment put into finding alternatives to
the chlorinates, trying to provide operators with
“drop in replacement solvents” that would enable
them to retain their existing processes and avoid
the necessity to purchase expensive hardware.
Operators of solvent degreasing having been
thrown into a world of undefined regulation with
the assured risk of significant financial penalty for
non-compliance were overwhelmed with confusion
about what they were required to do to comply.
The fact that the UK government delayed the formal
adoption of the EU regulations for many years just
made the position significantly worse.
There was also the powerful combination of the
EU machinery OEM’s and their UK agents and the
EU based solvent suppliers forcefully dominating
the UK market promoting fully enclosed, automated
equipment. In many cases this proved to be the
appropriate solution for operators with high volume
and complex applications, however, in many less
complex or demanding cases it created even more
confusion and financial concern.
Meanwhile, manufacturers of technologically
improved open-top machines, with advanced
multi-stage perimeter cooling systems and some
with secondary enclosures and interfaced doors,
continued to focus on providing low consumption,
regulatory compliant, cost effective equipment
options for the operators who could not afford
nor had the necessity to pay the extremely high
cost of the EU style enclosed machinery. For many
operators, modern open-top machine design
enabled them to maintain operations below the
specified regulatory exemption limit and in some
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2019 - 2020
cases comply with the regulations.
Inline with open top machine development a lot of
work has been done to develop new solvents and
new solvent blends tailored to achieve specific
non-flammable, low toxicity, environmentally
favourable characteristics that provide operators
with the potential to have an independent choice
of product and process that best suits their specific
requirements. There have been many attempts to
establish the ideal “drop in replacement solvent”
to replace the standard chlorinates. Brominated
solvent has been a typical example of such an
attempt. Although it has been heavily challenged
on grounds of flammability and toxicology since
its early days of promotion, it has been used
throughout the period of change enabling many
operators to cope with the challenge of the
regulations. However, the true status of the product
is now confirmed, and it will be restricted from
use from July 2020. Interestingly, perchloroethylene
can be considered as a safe replacement for nPB
subject to using appropriate REACH compliant
equipment when consumption is above the
regulatory exemption level.
A positive example of product development has
been the co-solvent process, where a powerful
solvency agent, having a potential flammability
rating as an independent substance, is mixed
50/50% with a non-flammable rinse agent in
a wash compartment which is then contained
safely within a non-flammable rinse agent vapour
envelope. A second compartment containing
pure rinse agent is used to immerse rinse the
cleaned components. This non-flammable process,
performed within a modern open-top system
provides a strong solvency action, usually
associated with higher boiling point solvents,
plus an ultra-pure vapour rinse and flash dry
operation, all taking place at a relatively low
process temperature. Condensed rinse agent returns
to the process tanks maintaining the ultra-clean
quality of the rinse stage to ensure prolonged
performance. This type of process is particularly
suitable for critical cleaning of electronics and
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