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PEER-REVIEWED ARTICLE
Fig. 5. The effect of density variation on the analyzed parameters (modulus of rapture (MOR), modulus of elasticity (MOE), and internal bond strength (IB)) of the tested panels ( y - variable correlation equation, r 2 – coefficient of determination) No statistically significant correlations between density and MOR/MOE were found for the mixed poplar-pine boards (450 to 490 kg/m 3 ). The r 2 for IB ranged from 0.002 to 0.2153, which indicated no statistical significance. It was observed that both uneven density in the core layer and increased porosity resulted in a decrease in correlation between the density and mechanical performance of a board (MOR and MOE). Analysis of the data for the mixed poplar-pine boards showed lower correlation, which probably resulted from the variable rate of poplar and pine chips in the core layer. The compaction of the face layers that determine MOR and MOE was not altered. CONCLUSIONS 1. Compression processes during manufacturing of low-density particleboards depend on the species used, their heat transfer coefficients, and their moisture content. 2. These factors also affect heating times, so that pressing regimes must be carefully considered and empirically verified. 3. Raw material with lower density used for particleboard manufacturing requires either prolonged pressing times or higher heat transfer into the mat core.
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Boruszewski et al . (2016 ). “Particleboard density ,” B io R esources 11(3), 6909-6919.
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