WICONA energy-saving coating for aluminium profiles passes quality tests

The innovative low-E-coating from Hydro Building Systems has made a further important step towards successful serial production and has passed the Qualicoat-Tests necessary for professional marketing and is therefore suitable for application on the outside of buildings without limitations.

The U-value of a construction can be lowered by up to 30% through the low-E-coating – without having to structurally change the aluminium profile. This effect is enabled by disc-shaped metallic pigments which align themselves in parallel when the powder coating near to the surface melts. The pigments decrease the heat radiation through the aluminium construction, and in this way reduce the loss of heat of the building envelope. This innovative surface technology was developed through many years of research work and has the potential to be used outside of the building industry. The perquisite for this is, amongst other things, a corresponding Qualicoat-certificate (class 1).

Low-E possesses a high chemical and mechanical stability and fulfils the high standards of the class 1 Qualicoat-test. This means that it can be used for outdoor architectural purposes, without limitations.

Tests of the chemical quality

The chemical quality is evaluated in the Qualicoat-Tests through the acetic-acid-salt-spray-test. The result of the test, carried out in accordance with the EN ISO 9227 criteria, over a period of 1000 hours showed no blistering on the coating whatsoever. The second test of the chemical quality encompasses the exposure to condensation with a sulphur-dioxide containing atmosphere (EN ISO 3231). Neither corrosion under the coating nor changes to the colours were established here. Furthermore the Wicona-coatings proved to be durable against mortar (ASTM D 3260; mortar test), there were no changes in colour and the mortar was easy to remove from the surface. In the accelerated weather test as per EN ISO 11341 the coating was weathered for 1000 hours, a 30 percent loss of lustre was observed; the standard allows a maximum of 50 percent. However experts find that the testing method as per EN ISO 2813 is not very suitable for metallic powder coatings.

Tests of the mechanical stability

In order to fulfil the Qualicoat-criteria for mechanical stability, the coatings had to pass the bullet impact test and the mandrel flex test (bend test) as per EN ISO 1519. Both passed without any problems, there was neither fissuring nor delamination of the surface.

Finally a so called “Florida-Test” was carried out on the coatings over a period of twelve months. The surfaces must survive this period undamaged and with only minimal, strongly defined changes to the coating surface, in order to be classed as highly weather resistant. In this special test, coated aluminium sheets are tested for outdoor usage under the natural, high UV-load of the US state of Florida, with regard to its effect on the shine and colour retention of the coating. This test was also passed.