Application of droplet dynamics analysis for assessment of water penetration resistance of coating (1)
Published: 2002
Walinder, M. E. P.
Privu, D.
Gardner, D. J.
Shaler, S. M.
Publication Name: Proceedings of the 2001 Annual Meeting of the Forest Products Society
Publication URL: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=Sz3gNNEAAAAJ&cstart=20&pagesize=80&citation_for_view=Sz3gNNEAAAAJ:eflP2zaiRacC
Abstract:
Moisture uptake in wood or wood-based products reduces their performance and durability. Development of improved, more effective coating systems that provide durable protection and thus extend the service life of wood products depends largely on a good understanding and accurate methods to assess their effectiveness in resisting water penetration into wood. The method presented in the paper is aimed at enhancing the development of new coated wood products through extending the current state of knowledge on water resistance of coatings applied onto wood products, and by providing a new robust evaluation tool. The primary objective was to investigate the applicability of droplet analysis methodology for comparative assessment of water resistance of coatings. The experimental method used for droplet dynamics analysis was extended so that water penetration and surface properties of coatings could be determined in the course of the same test. In this method, droplets of water were deposited on specimens of coated surfaces, and changes in droplet volume due to evaporation and penetration into the coatings were registered on a series of digital images. Digital image analysis techniques were used to determine changes in dimensions and volume of the droplet. Reference tests on impermeable surfaces enable an accurate determination of the amount of moisture penetrating the test surface by subtracting the evaporated volume. Advantages and shortcomings of the method are discussed.