Abstract
Coniferous roundwood of common qualities is usually industrially processed in chipping-sawing lines which arewidely limited to log diameters of <45 cm. The rising stock of large-diameter softwood in the DACH-region,especially of Norway spruce, necessitates a rethinking of the processing of sawn wood and the subsequentproducts produced. One possible option for processing such large-diameter roundwood is through rotarypeelingin combination with an extended peeling thickness range to produce a new class of raw materialscalled "thick peeled products (TPPs)" (thickness >6 mm). This paper demonstrates that peeling of softwood upto a thickness of 20mm is possible but this results in deeper lathe checks (up to 85% of the TPP thickness).Due to the wide variation in the quality of the peeling logs, a first physical / mechanical characterisationof the base material leaded to a mean static MOE of ?t,0,cor,mean = 9.3 GPa and a mean tensile strength of?t,0,cor,mean = 19.6MPa. In this study, the peeling process achieved a maximum yield of 92.5% and revealedno disadvantages in terms of mechanical behaviour for shorter soaking duration, i.e. less process energy.Additional recommendations regarding optimal peeling process parameters are given in this paper.
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