Properties of Particleboards Made from Mixture of Oversized Fibers from MDF Waste Process and Wood Particles of Norway Spruce ( Picea Abies )

The present study aims to evaluate the properties of particleboards made with a mixture of oversized fibers taken from the MDF waste production process and commercial wood particles. Four types of oversized fibers were used: on the one hand, dried and non-dried, and on the other hand, mechanically divided and undivided. Single-layer particleboards were manufactured by mixing 90% of wood particles with 10% of oversized fibers. A positive influence of the use of oversized fibers on the bending strength (MOR) and internal bond (IB) strength of the particleboards was found, with no apparent effect on the modulus of elasticity (MOE). In particular, the replacement of wood particles with oversized fibers increased the MOR and IB values by 24-36% and 36-52%, respectively, compared to the control boards made of 100% wood particles. Scanning electron microscopy and reflected light microscopy revealed that this is due to the optimal filling of the empty zones between the large-size particles of the boards by small-size fibers. Particleboards made with a combination of oversized fibers and wood particles met the moisture content, density, IB and MOE requirements specified in the EN 312 standard for P2-type boards for interior fitments for use in dry conditions.