PuK - Process Technology & Components 2024

Components
Seals
New sealing options for CIP/SIP processes
Food industry challenges for elastomer seals
Dipl.-Ing. (FH) Michael Krüger
Demands are becoming ever-more
stringent in the food industry nowadays,
due to continually refined
production processes. But greater
streamlining depends on having
more aggressive cleaning media or
higher sterilisation temperatures.
As hygienic design is used in modern
production systems more and more,
the tighter installation spaces it entails
means that elastomer seals
need to exhibit even lower swell.
This is a major challenge for those
in the industry and a frequent problem
which the designers or users of
such production systems have to
solve.
All materials that come into contact
with the food to be produced during
the production process must fulfil the
relevant standards/approvals (e. g.
FDA, Regulation (EC) 1935/2004). But
it involves far more as well. Additional
too having general media resistance,
such as withstanding greasy media
or aromatics and essential oils, which
are critical for elastomeric sealing
materials, the seals must also be
usable in today's CIP or SIP processes
Fig. 1: Plant in food production (Image credit: Shutterstock@Parilov)
Fig. 2: O-Ring in Aseptic sterile screw connection according to Hygienic Design
(Image credit: COG)
(CIP = cleaning in place; SIP = sterilisation
in place). The interaction between
the media having to be sealed
and what are, at times, very aggressive
disinfectants/cleaners or hot
steam used in the sterilisation process,
with operating temperatures of
up to 149 °C, imposes huge strain on
the material. All of which is why many
elastomer seals fail in the long term.
Costly consequences include more
frequent maintenance intervals, a
greater need for repair work or even
production downtime.
Increasingly stringent production
requirements
The demands imposed on elastomer
seals in the food industry are
becoming increasingly complex. As
the stakeholders involved gradually
phase out or eliminate the use
of preservatives, the contamination
genera ted during the production
process in pipework, valves and
pumps has to be cleaned and removed
using ever-improving detergents
in the CIP process. At the same
time, people are accelerating production
cycles to boost productivity.
This means the cleaning process has
to be shortened further still, using
even more aggressive CIP media. Although
this may ultimately benefit
production, it poses a major challenge
for seal manufacturers, given
the enormous demands imposed on
elastomer materials from this kind of
approach and the fact that few can
withstand long-term use.
110 PROCESS TECHNOLOGY & COMPONENTS 2024