PuK - Process Technology & Components 2024

Components
Seals
Resistances always depend
on temperature
As a general rule for designers and
users, one should be aware that resistance
of the electrometric sealing
materials depends highly on the actual
operating temperatures. For
example, positive resistance to a seal
medium may be given over a lower
temperature range, but not at significantly
higher temperatures.
New FEPM seal material for the
food industry
EPDM seals are often used in the food
industry, given their resistance to hot
water and steam. The downside?
They are far less resistant to grease
or acids at higher temperatures. That
is why FKM materials are preferred
for applications with higher grease
content or more aggressive media.
These, in turn, have downsides when
used with hot water or steam, although
special FKM materials can be
used in such applications. But even
these materials reach their limits
when the temperature of the media
in the cleaning process is excessive
or the material swells too much within
the hygienic design spaces. The resulting
balancing act for designers
and users is far from easy.
The independent manufacturer
C. Otto Gehrckens (COG) has
de veloped a new FEPM compound,
“AF 680”, for these critical areas in
the food industry. This innovative
formulation also features a specially
designed AFLAS ® base polymer.
This AFLAS ® -based FEPM compound
is the first to be approved to FDA
21 CFR § 177.2600. The special seal
material compounded by COG is absolutely
reliable in use with SIP and
CIP processes, paving the way to deploy
it in exceptionally wide-ranging
applications in critical food production
areas or the periphery.
Unlike peroxide cross-linked
high performance FKM materials,
this new FEPM compound can easily
withstand the increasingly aggressive
alkaline (base) cleaning cycles at
high tempera tures (approx. 140 °C).
An EPDM material, conversely, would
be unusable in these areas due to
Fig. 3: COG FEPM "AF 680” seal (Image credit: COG)
the high temperatures and acidic
cleaning media involved. Even in
the high-temperature SIP process
at around 150 °C, the volume swell
of the FEPM sealing material is low
enough to render it still perfectly installable
within the confined spaces
of the sterile, hygienic-design fittings.
With an operating temperature range
of -10 °C to +230 °C and exceptional
chemical resistance, including to flavourings
and essential oils, this FEPM
material is ideal for use in demanding
food production applications.
The very appealing pricing, compared
to many peroxide cross-linked
high performance FKM or even the
extremely expensive FFKM (perfluorine)
materials, rounds off the AF 680
performance profile, as a pro duct offering
designers and users a clean solution
for demanding food industry
applications.
Conclusion
The use of modern elastomer sealing
materials in the food industry requires
professional support. More often
than not, approvals in accordance
with food regulations such as FDA
and Regulation (EC) 1935/2004 may
no longer suffice. These materials
must also cope with the usual interactions
in a production process. This
is often a difficult balancing act that
few sealing materials can achieve.
Manufacturer expertise, experienced
application advice and external, independent
testing make up optimum
conditions for a safe and satisfactory
sealing result. This is the only approach
offering ultimate peace of
mind for users and designers.
Expert advice from COG's application
engineers can be invaluable, especially
if the material is being used
in borderline areas or with significant
deviations from the test parameters.
Thanks to their extensive experience,
these specialists - all qualified engineers
- can often make sound recommendations
to designers and users
without the need for extensive and
costly testing. With numerous projects
in the food and pharmaceutical
industries already under our belt,
our wealth of experience can easily
be tailored to suit market needs. In
fact, our consultants often remain
one step ahead of users and their
requirements, applying their knowledge
to the problems faced by designers/users.
The Author:
Dipl.-Ing (FH) Michael Krüger,
Head of Application Technology,
C. Otto Gehrckens GmbH & Co. KG
Pinneberg, Germany
www.cog.de
PROCESS TECHNOLOGY & COMPONENTS 2024
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