Determination of physical and mechanichal properties of OSB produced with different adhesives

The main purpose of the thesis was to investigate influence of different adhesives and their mixtures on physical and mechanical properties of OSB panels manufactured in laboratory scale. OSB boards were produced using 80% Black pine (Pinus nigra A.) and 20% Scots pine (Pinus sylvestris L.) with following adhesives: urea formaldehyde (UF), melamin urea formaldehyde (MUF) and polymeres diphenylmethandiisocyanat (PMDI). In order to increase performance and reduce formaldehyde emission 5% and 10% PMDI was added to UF and MUF resines. The mixture was used in core layer of OSB panels. Density, thickness swelling, formaldehyde content, bending and internal bond strength were determined. In addition two different brown-rot fungies Coniephera puteana and Trametes versicolor were inoculated to samples and decay resistance test was made. Statistical analysis of results was performed. According to the results boards made with PMDI showed the best thickness swelling values. However addition of PMDI to UF and MUF adhesives in core layer had negative influence on both swelling thickness and internal bond strength values. Signifficant difference in lengthwise bending strength values between resins was not observed. The study showed that 5% addition of PMDI to core layer partially decreased formaldehyde emission. At the same time 10% addition of PMDI to UF resin caused a prominent decrease. In decay resistance test the best results were obtained for samples made with mixture of MUF and UF with 5% PMDI.