Test Methods to Predict the Microbial Attack of Water-Based Coatings

Organic coatings provide the ultimate surface to protect many external structures from the degradative effects of water, radiation and micro-organisms.

Waterborne coatings are a main thrust of modern ‘clean' technology, with the intention to achieve the performance and durability of established solventborne systems. However, current raw materials and formulation changes are likely to increase microbial susceptibility and decrease efficiency.

Test methods are essential to enable industry to develop and assess the protective functions of coating product.

This project undertook visual spoilage assessments, image analysis and microbial ecology assessments (CABI Bioscience) on a series of coated panels at three exposure sites (according to an experimental design). Weather conditions were monitored at the three sites with the intention of identifying the conditions for fungal growth that might be used to improve the current BS3900:G6 test for fungal growth. The visual spoilage analysis provided a benchmark for trial laboratory test experiments. The microbial ecology analysis was used to comment on and improve the choice of laboratory test inocula. Image analysis provided an interesting insight into the development of fungal growth on different coated surfaces.

An extension project was undertaken to look at a more diverse selection of exposure sites (Project EXMAW).

Further Information

If you are interested in this, or any other project, please contact Richard Holman.