Long-lasting paint owing to small particlesAnders Larsson at YKI, Institute for Surface Chemistry, pondered over an idea. By adding silica particles in paint to increase the hardness of the paint's surface, it becomes more resistant to contamination and biological growth. Extensive outdoor tests have now shown that the hypothesis is correct.
The first phase of the project was initiated in 2008 as a thesis. The scratch resistance was tested in an instrument which pulls two surfaces against each other. Scotch Brite was used in order to attain the scratch effect. The tests went well and therefore it was time to test whether it was also possible to attain a good effect against dirt retention in commercial outdoor paint.
Wooden boards from SP Wood Technology were painted in four white original paints and each paint with two different surface modifications of silica particles. The boards were mounted at a 45 degree angle on different parts of the field station of SP Wood Technology in Bogesund so as to allow maximum exposure to the weather and wind. The test lasted for nine months from the summer of 2009 to the spring of 2010. The final step was measuring the brightness of the paint in a black-white scale. This made it possible to determine how much darker each paint sample had become after it had been subjected to the force of the weather during the test period.
The paint samples with silica particles retained the shade in a better manner than the original paints. The tests show that the paint attains a self-cleaning characteristic and retains the whiteness. This opens possibilities for new products and product development. Work is now continuing for developing the concept for commercialisation.