GET – GREEN EFFICIENT TECHNOLOGIES – English Language

Components
Elastomer seals and biological fluids
Is organic the solve-all solution?
Applying elastomer seals with biogenic media
Dipl.-Ing. (FH) Michael Krüger
An ever-increasing number of biogenic
fluids are being used in wide-
reduce CO 2 emissions is also becom-
protect the climate protection and
ranging technical applications. Soaring
numbers in fact. And for many Moves like this also help wean peoing
an increasingly crucial argument.
different reasons. Despite an applicable
scope ranging from the che-
products described are renewable
ple off petroleum, since most of the
mical process industry and related raw materials. Ultimately, though, the
elements to usage in forestry, agriculture
and water management, helping a range of biogenic media
key thing making the difference and
deploying these biogenic media break through may have been legislation
in the form of EU directives.
poses an enormous challenge to elastomer
seals.
Many public tenders, for example,
prescribe the use of biogenic fluids in
Biological fluids are environmentally construction vehicles.
friendly, rapidly biodegradable and Even so, hurdles remain to the
non-toxic media, most often produced
from biomass. But why are ids with existing mineral oil-based
wholesale replacement of such flu-
more people using such fluids and media. For many components, some
what is the main motivation? As well of the effects remain unknown and
as the move to a greener approach numerous elastomer seals are also
and avoid vehicles contaminating unsuitable for this application. Here,
soil or bodies of water, the need to carburettor fuel E10 is introduced as
Fig. 1: Biodegradable hydraulic fluids in mobile hydraulics. Photo: Fotolia/GHotz
a result of regulatory market interventions
and similarly, it triggers a
different response in many components
compared to conventional
petrol. Accordingly, this impacts on
the entire chemical process industry,
directly and indirectly, when producing,
storing and transporting media
like these.
Issues when deploying hydraulic
fluids in sensitive ecosystems
Generally speaking, the greenest fluid
solutions involve no fluid escaping
from machinery in the first place. But
however cutting-edge the machines
in place, leaks can still contaminate
bodies of water and soil when stationary
hydraulic systems like locks,
weirs and hydroelectric power plants
are used. The same applies when
operating construction machinery,
piste equipment in the mountains,
and agriculture and forestry equipment.
The key here is ensuring the
hydraulic fluids and lubricants are
free of substances with a critical ecotoxicological
impact.
This explains the increasing use
of biodegradable hydraulic fluids in
hydraulic drive technology. Beware
however - they can severely attack
conventional FKM seals and render
long-term use virtually impossible.
Biodegradable hydraulic fluids comprise
either triglycerides, which are
often vegetable oils (e.g. rapeseed oil)
called HEES (hydraulic environmental
ester synthetic) or synthetic esters
known as HEES. These fluids are designated
as class I pollutants.
In modern hydraulics, more
and more special high-performance
hydraulic fluids are also being used.
While they contain additives, they are
not based on mineral oil. These substances
constitute synthetic, anhydrous
liquids (HFD), which have a
higher density than mineral oil and
are flame retardant. Examples include
32 GREEN EFFICIENT TECHNOLOGIES 2022