engleski

Influence of Knots on Classification of Timber Assortments of Silver Fir into Quality Classes

The classification of timber assortments of silver fir into quality classes depends on the occurrence of wood defects. Knots are the most common defects appearing on fir assortments. The aim of this research was to establish the influence of size of knots and their position/height on fir trees (Abies alba, Mill.) on classification into quality classes of timber assortments that can be processed from the stem. Heights above ground, where maximum knot diameters can be found, increase with the increase of tree diameter at breast height. Only lower parts of stem of fir-trees can be used for processing veneer logs. Timber assortments processed from upper parts of trees with smaller-breast height diameter can be classified as saw logs of the highest quality (Class 1), but the quality class depends on the stem diameter. With larger breast height diameter trees timber assortments processed from the lower third of the stem meet the criteria for saw logs of the highest quality (Class 1).

knots; timber assortment; quality class; Abies alba

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