Zlateski, Goran
Preferred name
Zlateski, Goran
Official Name
Zlateski, Goran
Main Affiliation
Email
zlateski@fdtme.ukim.edu.mk
15 results
Now showing 1 - 10 of 15
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Item type:Publication, Impact of Veneer Layouts on Plywood Tensile Strength(Faculty of Forestry, University of Zagreb, 2017); ; The aim of the research presented in this paper is to study the plywood tensile strength through a change of the position of the layers in the structure of the panel around the central axis, without changing the number and the thickness of the veneers. So far it is known that the veneer layouts in plywood structure have significant impact on plywood bending properties. Besides these mechanical properties, the tensile strength of plywood is also a property that can defines the plywood use as structural or non-structural panel. For studying the impact of veneer layouts on plywpood tensile strength, experimental models of nine-layer plywood are made. The models are made from peeled beech veneers with thickness of 1.2, 1.5, 2.2 and 3.2 mm. The modelling is made on the basis of changing the position of veneers with thickness of 3.2 mm around the central axis. Pure water-soluble phenol-formaldehyde resin is used as plywood binder. The tensile strength of the plywood panels was tested in five directions: parallel and perpendicular to the face grain, as well as at the angle of 22.5°, 45° and 67.5° to the face grain of the plywood panel. On the basis of the obtained data for tensile strength in different directions of plywood panel the coefficient of the equality of the tensile strength of the plywood models was calculated (Ket). The coefficient of mass quality (Kmq) was calculated too. The research results showed that the different veneer layouts in plywood structure have significant impact on plywood tensile strength. All tested plywood models meet the defined values of tensile strength in accordance with the requirements of the national (МКС) standard for structural plywood for use in construction. The different layouts of veneer sheets in panel structure gives opportunities for production of panels with different strength characteristics. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Determination of the heat energy for hydrothermal treatment of ashwood (Fraxinus excelsior) by log soaking(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2023-09); The treatment of logs by soaking is a complex technological and thermal procedure, in which logs and prisms are used as raw material for the production of peeled and sliced veneers. Such treatment of logs is carried out in pools or pits constructed in the ground. By log soaking two significant changes to the wood are achieved, its coloring and the inevitable plastification of the wood fibers. During this procedure, the time required for air drying is significantly reduced. The soaking medium is fresh water or previously used water at an elevated temperature. This soaking treatment is particularly suitable for logs for the production of peeled and sliced veneer, from which resin must be removed. Soaking is also used when treating wood species that are sensitive to steaming. This paper provides an analysis of the thermal energy required for hydrothermal treatment by log soaking of ashwood (Fraxinus excelsior). The logs were intended for the production of peeled veneer. The log treatment was done in a reinforced concrete pool built in the ground. The total amount of heat for log soaking (Q) consists of effective heat (Qpv) and heat loss (Qzv). The procedure was conducted by the strong treatment mode, with a temperature interval in the range of 70 to 90 °C. The treated logs had a minimum mean diameter of 35,0 cm and a minimum length of 1,8 m. Log soaking was used as a method for defrosting of the logs, due to their low initial temperature, which was– 15 °C. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Comparison of log taper in different wood species(Department of Wood Technology, Faculty of Forestry and Wood Technology, University of Zagreb, Croatia, 2023-12); ; The rational yield of the sawlogs is one of the key factor for the prosperity of the sawmill capacity. One of the factors that significantly influence the maximum quantitative yield of sawlogs is the diameter taper. The diameter taper is an inevitable sawlogs occurrence and it is determined by the geometry of the logs. The diameter taper is defined as the difference between the diameters of the two ends of the log, alongside its length. Great differences between these two diameters adversely affect the percentage of maximum quantitative yield. This parametar plays a fundamental role in the classification of logs into quality classes. The aim of the paper is to compare the diameter taper in different wood species. Wood species of interest are: beech (Fagus sylvatica L.), pine (Pinus sylvestris, Pinus nigra), oak (Quercus sessiliflora), and fir/spruce (Abies alba/Picea excelsa). Log length is of important influence in the value of log taper. Therefore, the analysis for the different wood species will also present different groups of lengths, in order to determine the different values for the log taper. The selection of wood species is for the purpose of comparison of the taper values in deciduous and coniferous wood species. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Technical analysis of a metal chamber for direct steaming of beech lumber (Fagus sylvatica L.)(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2023-12); ; The aim of this paper is the technical analysis of a metal chamber for direct steaming of beech (Fagus sylvatica L.)-edged lumber with a thickness of 50.0 mm. The paper presents the basic parameters of the chamber and calculates the dimensions of the metal chamber and its capacity. The dimensions of the chamber with sawn lumber, the number of chambers, and the volume of the single lumber stack have been analyzed. The steaming of the wood is an important and complex operation during the processing of sawlogs into sawn lumber. Steaming, in addition to being a technological procedure, is also a thermal procedure. The steaming of the sawn lumber is carried out in the presence of water vapor in steaming chambers according to the following two methods: direct steaming of the sawn lumber and indirect steaming of the sawn lumber. In the method of direct steaming of lumber, the steaming medium is saturated water vapor. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Solar drying of wood(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2023-12); ; Solar energy represents an alternative source of energy supply, which has also found its application in wood processing technology. In particular, solar energy finds great application in the field of wood drying. Solar energy is defined as the emitted light and heat produced by the sun, which is harnessed with the help of developing technologies such as solar collectors, photovoltaic cells, solar and thermal collectors, various types of solar architecture, plantations and reactors that use molten salts, and technologies of artificial photosynthesis. The purpose of this paper is to give a brief overview of solar drying technology. A special review is given to solar drying methods. The method of work does not cause experimental research in practice but represents a collection of used literature and individual research. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Processing sawlogs into parquet blanks(FACULTY OF FOREST INDUSTRY – UNIVERSITY OF FORESTRY – SOFIA, 2024-12); ; ; ; The term parquet refers to a floor covering made of solid wood, consisting of interconnected slats in a horizontal plane. A parquet strip is the principal constructional element of the parquet. This wooden strip is obtained as a result of processing the flooring blank. In the sawmill processing of the sawlogs, the flooring blanks are sawn from the sawlogs, mostly in the radial and tangential direction. For such a purpose, sawlogs from domestic species and foreign species are used. Most dominant in this manner are the hardwood species, although softwood species can be used too. Among the domestic species, the most are beech, oak, acacia, elm, ash, and from the softwood species pine and larch. The paper focuses on the maximum quantitative yield of beech and oak sawlogs intended for processing into parquet blanks. The sawing was conducted on a bandsaw. The blanks were with a thickness of 25,0 mm. The sawlogs belonged to the I, II, and III quality classes. A total of 12 sawlogs were processed, 6 from beech (Fagus sylvatica L.) and 6 from oak (Quercus robur). All sawlogs were with a constant length of 3,0 m. The mean diameter for beech and oak sawlogs was in the range of 34,0 to 36,0 cm. The average value for the quantitative yield for beech sawlogs from I, II, and III quality classes was 37,90%. For the oak sawlogs from I, II, and III quality classes the average value of the quantitative yield was 39,40%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Analysis of heat and steam consumption during artificial convective drying of oak sawn timber of different thickness(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2023-09); ; ; ; In the paper, the consumption of heat and steam of oak sawn timber with a thickness of 25,0 and 50,0 (mm) are analyzed under conditions of classic convective drying. The drying mode is compiled on the basis of data on the temperature of the drying agent (air), the relative humidity of the air and the speed of air movement in accordance with the current value of moisture in the wood. The heat consumption is analyzed in all stages of the drying cycle such as heating the wood, active drying of the wood, equalization of the average moisture in the wood and conditioning, i.e. equalization of the moisture in the cross-section within ± 2.0 (%). The moisture content of sawn timber at the beginning of drying is about 55,0 (%) and at the end of drying is 10,0 (%). The sawn timber are intended for the production of solid wood panels. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Analysis of heat consumption during convective wood drying of beech sawn timber of different thickness(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2025-09); ; In the paper, the heat consumption of beech sawn timber with a thickness of 50,0 and 70,0 (mm) are analyzed under conditions of classic convective drying. The drying mode is compiled on the basis of data on the temperature of the drying agent (air), the relative humidity of the air and the speed of air movement in accordance with the current value of moisture in the wood. The heat consumption is analyzed in all stages of the drying cycle such as heating the wood, active drying of the wood and conditioning, i.e. equalization of the moisture in the cross-section within ± 2.0 (%). The moisture content of sawn timber at the beginning of drying is about 45,0 (%) and at the end of drying is 8,0 (%). - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Analysis of the influence of the length of beech sawlogs (Fagus sylvatica L.) on the maximum quantity exploitation(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2021-09); ; ;Krstev, MarijaMore than two decades have passed since scientific research was done on the influence of the length of beech sawlogs on the maximum quantity exploitation, so therefore there is no new data on this topic. For this particular aim, an analysis was done regarding beech sawlogs, a wood species that dominate this region in sawmill technology and processing. The analyzed logs were graded according to the European grading standard. The logs were inherent to the Ist and IInd quality class. The sawlogs were with the length of 2,0; 3,0 and 4,0 m. The sawlogs with a length of 2,0 m were with a measured diameter at a range from 31,0 to 52,0 cm, at the narrower end of the log, and on the wider end from 32,0 to 53,0 cm. There were 15 analyzed logs with a wood mass of 4,2 The logs with the length of 3,0 m were with a measured diameter at a range from 33,0 to 50,0 cm, at the narrower end of the log, and on the wider end from 35,0 to 54,0 cm. The analysis covered 15 logs with a wood mass of 6,5 The logs with the length of 4,0 m were with a measured diameter at a range from 35,0 to 52,0 cm, at the narrower end of the log, and on the wider end from 39,0 to 56,0 cm. The number of analyzed logs was 15. The wood mass of the logs was 8,9 The total count of analyzed logs was 45 and the amount of processed wood mass was approximately 22,0 The log diameter taper (S) of analyzed logs was as follows: for the length of l = 2,0 m → 0,5 ÷ 1,0 cm/m, Ssr = 0,54 cm/m, logs with a great mass; for the length of l = 3,0 m → 0,66 ÷ 1,33 cm/m, Ssr = 1,01 cm/m, logs with a full mass; for the length of l = 4,0 m → 0,75 ÷ 1,5 cm/m, Ssr= 1,23 cm/m, logs with a poor mass. Maximum quantity exploitation (P) of the different lengths of the logs was as follows: for the length of l = 2,0 m → P = 66,60 ÷ 68,32 %, Psr = 67,26 %; for the length of l = 3,0 m → P = 64,20 ÷ 66,99 %, Psr = 65,16 %; for the length of l = 4,0 m → P = 61,07 ÷ 62,53 %, Psr = 61,10 %. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Yield comparison of beech (Fagus sylvatica L.) and fir/spruce (Abies alba Mill./Picea abies L.) logs in the sawmill processing industry(Faculty of Design and Technologies of Furniture and Interior - Skopje, 2025-12); ; ; Sawmilling technology in Macedonia is primarily characterised by small- to medium-capacity sawmills, many of which operate with mixed species and variable equipment configurations. These sawmills typically process between 1500 and 5000 m³ of roundwood annually and play a crucial role in the domestic wood industry. The technology employed often includes vertical bandsaws for primary sawing and simple layouts for material flow. Beech (Fagus sylvatica L.) and fir/spruce (Abies alba Mill./Picea abies L.) are among the most commonly processed species, representing a significant share of the raw material input due to their abundance, accessibility, and economic relevance. Beech is predominantly used in furniture production, while fir/spruce is more common in construction and structural applications. This paper presents a focused comparative analysis of raw material yield efficiency between beech and fir/spruce logs in a primary processing setting. The study was conducted at the MARKISTO sawmill in Leskoec, Ohrid, a representative facility within the North Macedonian context, operating with a capacity of 2,500–3,000 m³ per year. A total of 160 logs from two standardised lengths (4.0 m and 5.0 m) and I, II, and III quality classes—80 from each species—were analysed. The objective was to quantify and compare the percentage yield of sawn timber relative to log volume, under real production conditions, without altering existing workflows. Key influencing factors such as log diameter, taper, and wood defects were recorded and assessed. Results indicated that fir/spruce logs generally achieved higher yield rates than beech, particularly in the higher quality classes. For instance, Class I fir/spruce logs yielded up to 10–15% more usable lumber compared to Class I beech logs, mainly due to more uniform structure and lower waste values. In contrast, beech logs, especially from lower quality classes, were more affected by natural defects like heart checks and curvature, reducing the quantitative yield despite similar or larger diameters. The study confirms that both species and log quality significantly affect sawmill efficiency and that careful log selection and classification are essential for optimising material recovery.
