Improving the technology of cross-cutting the sawn part of a tree trunk with core rot

Introduction. The primary objective of roundwood processing is the effective application of the harvested timber. One method to enhance the efficiency of timber use is to obtain sawn raw materials capable of yielding high-value sawn products. Currently, the methods are being developed to identify high-quality zones of round timber for the targeted use of raw materials. Harvesting wood, taking into account high-quality areas will allow for significant economic benefits due to more efficient use of wood. However, tree trunks are often affected by soil rot. When processing harvested wood, the lumpy part of tree trunks affected by soil rot is completely removed. At the same time, it represents the most valuable section of the tree trunk, comprising straight, layered wood with superior strength properties. The enhancement of wood resources can be achieved by the use of roundwood, notwithstanding the presence of deleterious soil rot, in the production of high-quality sawn products.

The aim of research is to improve the technology of cross–cutting the sawn section of  tree trunks in order to increase the volumetric yield of sawn grades.

Materials and methods. A mathematical model is utilised to describe the formation of the sawn section of a tree trunk. The allometric relationships between the variation in saw blade length and the dimensions of the trunk rot have been established. Optimisation of cutting and forecasting the output of sawn grades was conducted using the method of exhaustive solutions.

Research outcomes. An efficient technology has been developed for cutting the sawn section of a tree trunk, facilitating the manufacture of sawn segments from the bulk portion, despite the partial existence of destructive rot. It was found that as a result of using the traditional method of cross-cutting the sawn part of the tree trunk, the yield of sawn grades is 23-53 %. The application of a systematic approach to cross-cutting the sawn section of the tree trunk, along with the selective removal of grades exhibiting destructive decay, enables the attainment of 78-80% efficiency.

Conclusions. The production of sorts from the sawn part of the tree trunk with the presence of destructive rot increases the volume yield of the sawmill for the production of high-quality saw products.