Chemical Technology April 2015

Nünchritz: HDK ® plays an essential role for Wacker's fully integrated silicon site

HDK ® - the high end thermal insulation material

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

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.

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Chemical Technology • April 2015