Thesis researches how cyclical climate conditions affects some mechanical properties of particle and fiber based boards. We used four different boards, fiberboard, particleboard, construction fiberboard, oriented strand board which were exposed 12 months to cyclical climate conditions. Every cycle lasted 5 weeks, 4 weeks test samples were exposed to high relative humidity (85 +/- 5 %) and 1 week to relative humidity (35 +/- 5 %). Temperature was 20 +/- 2 °C. After exposure thickness swelling, shear strength, internal bond and bend strength was measured. We found out that long exposure had negative effect on mechanical properties of tested boards. We noticed the highest loss of mechanical properties at fiberboard and the lowest loss at construction particleboard.
|