Forest Products and Wood Science

This paper deals with the impact of heat treatment on the elastic and strength properties of two diffuse porous hardwoods, namely Fagus sylvatica and Betula pendula. Two degrees of the heat treatment were used at temperatures of 165 • C and 210 • C. The dynamic and static elasticity modulus, bending strength, impact toughness, hardness, and density were tested. It is already known that an increase in treatment temperature decreases the mechanical properties and, on the other hand, leads to a better shape and dimensional stability. Higher temperatures of the heat treatment correlated with lower elastic and strength properties. In the case of higher temperature treatments, the decline of tested properties was noticeable as a result of serious changes in the chemical composition of wood. It was confirmed that at higher temperature stages of treatment, there was a more pronounced decrease in beech properties compared to those of the birch, which was the most evident in their bending strength and hardness. Our research confirmed that there is no reason to consider birch wood to be of a lesser quality, although it is regarded by foresters as an inferior tree species. After the heat treatment, the wood properties are almost the same as in the case of beech wood.

Section: Methodsmentioning

confidence: 99%

Elastic and Strength Properties of Heat-Treated Beech and Birch Wood

Borůvka

Zeidler

Holeček

et al. 2018

“…In reality, however, when transporting timber, the high variability of the transported assortments made of different species and the variable moisture content of wood do not allow a precise determination to be made of the weight of the transported raw wood material [23][24][25][26]. These differences very often influence the excessive weight of the truck unit [27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Total Weight and Axle Loads of Truck Units in the Transport of Timber Depending on the Timber Cargo

Trzciński

Moskalik

Wojtan

2018

When transporting timber, the high variability of species, assortments and moisture content of the wood raw material does not allow the weight of the transported timber to be precisely determined. This often contributes to the excessive weight loading of the entire truck unit. The aim of the research is to present the variability of the total weight of truck units with wood cargoes (GVW-gross vehicle weight) depending on the weight of the empty unit and the transported timber load, as well as to analyze the changes in GVW, unit loads of wood and load on individual truck unit axles depending on the season. This study analyzes the total weight of truck units for 376 transports of Scots pine timber at different times of the year. The total weight of the truck units depends on the weight of an empty unit and the weight of the load. GVW was determined by using a weighbridge to weigh the vehicles and then the empty unit after unloading. The weight of the load was obtained as the difference between GVW and the tare. It was found that GVW differed significantly depending on the truck unit used, ranging from 43.60-58.80 Mg, often exceeding permissible limits for public roads. The individual axle loads for various truck units were also analyzed. The obtained results indicate that these loads are more equally distributed in the case of five-axle trucks compared to six-axle ones.

“…The timber's density and moisture content play a significant role in determining its load mass. For freshly harvested pine logs, the mass of one cubic meter is estimated at 750 kg [31]. The density of the wood also depends on the part of the trunk from which a given assortment originates.…”

Section: Introductionmentioning

confidence: 99%

Multi-Factorial Load Analysis of Pine Sawlogs in Transport to Sawmill

Tymendorf

Trzciński

2020

This study analyzed the variability of truckloads of large-sized pine logs transported to a furniture manufacturing mill, depending on the origin of the timber, delivery period, length of the transported logs, volume of the load and its mass. It was assumed that the volume and mass of the transported timber load depends on the season of the year and the origin of the timber, which has a significant impact on the mass of one cubic meter of the load. The analysis of the wood origin parameters (location of its growth) took into account the type of forest habitat, soil type and stand abundance. The characteristics of the tree parameters from which the roundwood was obtained took into account age, diameter at breast height (DBH) and height of the stand. The origin of the timber was determined for 1063 timber loads from 40 forest districts transported over a 12 month period. We obtained an average timber load volume of 29.34 m3 which includes single shipments differing significantly in their volume of between 24.21 and 36.51 m3. The origin of the timber, habitat conditions and stand parameters of the harvesting site influence load mass and the mass of 1 m3 of load. The delivery date has an impact on the studied elements of the sawlogs load, with two similar periods—spring and summer. The volume of the transported timber is already at a stabilized level in accordance with legal regulations, which is no longer dependent on other factors and only on the accepted conversion factors for roundwood density and the mass of the empty vehicle set. This has not influenced a reduction in the mass of the transported timber.