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Chemical Technology • April 2015
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of two half-shells and support elements that are bonded
together. During the assembly of rotor blades, the adhesive
must not run after it has been applied, as this may weaken
the bond and therefore the rotor’s mechanical strength.
For the application, itself, however, the adhesive must not
be of low viscosity, otherwise the tubes and application
equipment will block.
HDK
®
can meet such extreme rheology requirements
very well. HDK
®
-modified adhesives have a low viscosity
under pressure and shearing, yet do not sag once applied.
Furthermore, HDK
®
prevents sedimentation. It retards the
deposition of the adhesive formulation’s solid components,
which considerably extends the shelf life.
High-performance insulating materials
made of HDK
®
Pyrogenic silica possesses outstanding thermal properties.
Depending on the application, its thermal conductivity, λ,
is typically between 4 and 25 mW/(m * K). Hence, insulat-
ing materials made of HDK
®
are extremely effective. For
example, the insulation performance of a 15 mm-thick
HDK
®
vacuum insulation panel is comparable with that of
a 100 mm polystyrene panel.
HDK
®
offers high thermal insulating capabilities at
minimal space usage. Such properties are not commonly
needed in everyday life. In most applications, conventional
insulating materials are entirely sufficient. However, if very
high or low temperatures must be controlled and there is
Nünchritz: HDK
®
plays an essential role for Wacker's fully integrated silicon site
HDK
®
- the high end thermal insulation material