Evaluation of Water Repellency of Treated Wood Using Several Alternative Methods
L Jin, A F Preston
In this study, the results of water repellency testing using a digital swellometer method for water-borne organic-preservative systems with water repellent additives are reported. The findings suggest that the traditional method of using matched untreated controls as a reference developed from historic solvent-based treatments for determination anti-swelling efficacy (ASE) may underestimate the actual effectiveness of a given water repellent (WR) system in water-borne treatments. The results show that using a water-treated control may provide a more accurate measurement of the water repellency with any given water repellent additive system for water-borne preservatives. The potential of using data generated from digital swellometer testing are also discussed. These outcomes include water resistance performance monitoring for commercial products, providing indications of the system differentiation in terms of formulation chemistries and their subsequent influence on the water repellency, developing practical guidance and prediction of performance for the WR use-level based on the intended applications, and using characteristics of the swelling curves to estimate important information regarding any dimensional stability imparted by the treatments.
Keywords: organic preservatives, waterborne preservatives, water repellent (WR), additives, water repellency, anti swelling efficiency (ASE), swellometer testing, dimensional stability