Deterioration of wood-based boards subjected to outdoor exposure in Tsukuba

Abstract

Various types of wood-based boards were analyzed for deterioration after being exposed to an outdoor environment for 5 years in Tsukuba, Japan. In phenolformaldehyde resin bonded particleboard (PB(PF)) and aspen oriented strand board (OSB(aspen)), longer exposure caused a greater reduction in the modulus of rupture and internal bond strength, an increase in the coefficients of variation, and a decrease in 95 % lower tolerance limit at the 75 % confidence level (95TL). Nail-head pull-through and lateral nail resistance were also reduced by outdoor exposure, but their coefficients of variation and 95TL were not significantly affected. In contrast, methylene diphenyl diisocyanate bonded medium density fiberboard (MDF(MDI)) only showed a slight deterioration of these properties even after 5-year exposure, and the coefficients of variation and 95TL hardly changed. After 5-year exposure, the retention of shear load in one-plane at relative displacement of 1.0 mm was high in MDF(MDI) and OSB(aspen) at 93.5 and 78.5 %, respectively, but low in PB(PF) at 41.1 %. As with PB(PF), OSB(aspen) also showed a sharp decrease in the modulus of rupture and internal bond strength, but only slightly reduced shear load in one-plane.

Effects of water soaking and outdoor exposure on nail joint properties of particleboard

“…The LNR of the board exposed outdoors was measured at the edge, whereas the NHPT of the board exposed outdoors was measured at the center (Fig. 2) [8]. Thus, the LNR of board exposed outdoors decreased more than that of board soaked in water.…”

“…Phenol-formaldehyde resin-bonded particleboard (PF board) and methylene diphenyl diisocyanate resin-bonded particleboard (MDI board) were used in the experiments. Further details are provided in the references [8][9][10][11]. The boards were commercial products that did not include detailed information such as binder content.…”

“…In an experiment, nailed boards were exposed outdoors at four sites in Japan for 7 years (2004-2011), and the nail joint properties were evaluated [8,9]. The relationships between nail joint properties owing to water soaking and those owing to outdoor exposure were then compared and analyzed.…”

Effectiveness of principal component analysis for analyzing particleboard subjected to outdoor exposure

“…For the strength tests, modulus of rupture (MOR) and internal bond strength (IB) were measured. Further details can be found in previous reports [5,7,8]. Asahikawa, Noshiro, Morioka, Tsukuba, Maniwa, Okayama, Shizuoka, and Miyakonojo are numbered from 1 to 8, respectively, as listed in Table 1.…”

Estudo da durabilidade de painéis de partículas de bagaço de cana de açúcar e resina poliuretana a base de óleo de mamona para aplicação na construção civil

“…Além disso essas tensões são incrementadas pelas condições climáticas circundantes. (KORAI et al 2013). Mudanças na temperatura conduzem a um gradiente térmico entre a camada superficial e interna dos materiais particularmente em materiais com baixa condutividade térmica o qual resulta numa diminuição das propriedades mecânicas do material e pode conduzir a formação de finas fissuras .…”