The aging effects of water immersion treatments in wet-bending for standardized testing of wood panels

Abstract

The durability of wood-based panels is one of the most important properties when they are used in residential construction. The main objectives of this study were to investigate the quantitative relationship between the Wet-bending A test and the Wet-bending B test, examine the aging effects of the treatments specified in the wet-bending methods, and discuss the relationship between wet-bending and outdoor aging tests conducted in Shizuoka, Japan. Wet-bending tests, internal bond tests after humidity treatment, and outdoor aging tests in Shizuoka were conducted using eight types of commercial wood-based panels. A linear relationship was found between the load-carrying capacity (LCC) from the Wet-bending A test and the LCC from the Wet-bending B test. The LCC from Wet-bending B could be obtained from LCC from Wet-bending A by multiplying it by 0.9, which may be applicable as a quantitative ratio of aging effects between the two. LCC for methylenediphenyl diisocyanate-bonded panels recovered to almost 100% of the initial strength. A certain relationship was found between the LCC after Wet-bending A and the LCC after a 1-year outdoor exposure in Shizuoka. Internal bond strength showed a good correlation between the JIS-A treatment and the 1-year outdoor exposure treatment. © 2007 The Japan Wood Research Society.