DP452, A New Heat Resistant Insulation Coating
Such it was with a unique Aerogel insulation enquiry which our lab received some time ago.
Aerogels are derived from liquid gels in which the liquid component of the gel has been replaced by a gas. The result of this process is a solid material with extremely low density and exceptionally low thermal conductivity. Aerogel’s are solid, rigid materials and do not look like typical ‘gels’ as we know, they are composed of over 98% air. The lack of solid material allows for a material which is almost weightless.
Due to the fact that Aerogels are composed mostly of gas, they are exceptionally effective thermal insulators. Beginning around the year 2000, the commercial manufacture of industrial silica Aerogel blankets commenced. These blankets are manufactured by combining the silica Aerogel with fibrous reinforcing material, thus converting the brittle Aerogel into a highly durable, flexible material. These Aerogel blankets have a loose fibrous surface and feel exceptionally dry to the touch. They are commonly used in insulating media in building construction , insulating fridges and boilers.
In fact, in any industrial application where insulation from heat or cold is required, Aerogel blankets will satisfy most applications. However, in some applications, the dusty, fibrous nature of silica Aerogel blankets is problematic. And for a variety of applications, the liberation of loose fibres, inevitable while the Aerogel blanket is being cut or installed, will be problematic.
Last year, our research laboratories were contacted by a machinery manufacturer, who wanted to use silica Aerogel blanket in a unique insulation application. However, the application could not allow dust fibres to damage other delicate surfaces and components. The request was for a heat resistant coating which could be sprayed onto the pre-cut pieces of silica Aerogel material. A reasonably simple request, except for the fact that the coating must be able to withstand 300°C!
Our laboratories got to work and after several trial and error formulations, DP452 was born.
DP452 is a silicone terpolymer which has been especially formulated as a heat resistant encapsulation coating for use with fibrous insulation materials such as Cryogel™, Pryrogel™ & Spaceloft™. In laboratory tests, the product has been shown to have a heat resistance of approximately 300°C when applied at a dry film thickness of a minimum of 25µ, but more preferably 50µ. DP452 is very effecting in wrapping all Aerogel blankets, providing a heat resistant coating which effectively prevents the liberation of loose Aerogel fibres.
Coated materials are subsequently used in the fabrication of various linings for pipes, engines etc. DP452 is also suitable for use with Lumira™ and ThermalWrap™ materials.
DP452 is typically applied via spray application. Excellent results have been achieved using a DeVilbiss HD spray gun, with a 1.1 mm tip & needle and a 1.2 mm air-cap. In certain applications and where the area being coated in small, the product may be applied by brush.
DP452 joins the range of successful Aerogel adhesives which have been developed & successfully commercialised over the past few years. Soon to be commercialised will be DP454, an ultra high temperature resistant encapsulation adhesive, specifically developed for use with Pyrogel™. In laboratory tests, DP454 has been shown to have a heat resistance of approximately 750°C.
Further information on DP454 will be published in due coarse. For further information on both coatings and adhesives, please contact our laboratories.
The words Spaceloft™, Cryogel™ & Pyrogel™ are the registered trademarks of Aspen Aerogels®™.
The words Lumira™ and ThermalWrap™ are registered trademarks of Cabot Corporation®™.