On the Rheological Behavior of Pine (Pinus sylvestris L.) Shavings and the Briquettes Obtained from Them

The aim of this paper is to carry out a rheological study of the pressing of pine wood sawdust, after which obtaining briquettes from the same wood material with a hydraulic installation and analyzing their properties. In order to know the rheological behavior during pressing, the fractions resulting from sorting the sawdust with 4 x 4, 3 x 3, 2 x 2, and 1 x 1 mm2 sieves were used, respectively, six fractions (the fraction larger than 4 x 4 mm2 and the smaller one of 1 x 1 mm2 are added) and a specific pressing device, placed on a universal testing machine. The results obtained in the rheological study showed that the obtained density does not increase proportionally with the pressure, the best results (density of 1030 kg/m3) being obtained at a pressure of 180 MPa. Within the briquettes, higher densities were obtained for the sawdust fraction smaller than 1 x 1 mm2, but the breaking strength was higher for the fraction larger than 4 x 4 mm2. As a general conclusion, it was found that pine sawdust is easily compressible, and the briquettes obtained from it have good properties for use in combustion.