Lamelirano drvo (CLT) kao alternativni oblik drva za gradnju

Wood, which is a natural and renewable material, is gaining increasing appreciation again and it is more and more commonly used in the building industry. The use of wood has been improved due to the application of modern bonding technologies (e.g. Glued Laminated Timber, Cross Laminated Timber), the development of modern production technology and improved methods of wood protection from fire. As large-size assortments of constructional timber in the form of light beams and boards are available on the market, it is possible to make stable and durable joints between individual constructional elements of a building. Among wood materials used for construction, CLT is increasingly used. It is applied in the construction of single-family houses, residential buildings, multi-storey buildings, public buildings, industrial and retail buildings as well as bridges. CLT was developed as a result of European research how to use short wood, left after the elimination of faults, for private construction. The trend very soon spread to the building industry in North America, Australia and Japan. CLT was more and more commonly used in multi-storey buildings due to its higher seismic resistance. At the beginning of the 30-year history of CLT, the use of this building material was minimal. However, due to the ecological trend and a wide range of economic factors (the value of material used and costs of production combined with high precision of finished products), this technology gained significant popularity. The surge of interest in wooden constructions also resulted from better distribution channels and technical approvals for different concepts of wooden construction boards. The following countries are leaders in the production and use of CLT: Austria, Germany, Switzerland, Sweden, Norway and the United Kingdom. In recent years, New Zealand and Australia have joined this group. CLT boards are exported to North America, Japan and Russia. The surge of producers and investors’ interest in CLT boards results from the production process diversity and construction variability. In consequence, there is an increasing number of concepts specifying the range of product application, depending on its strength and resistance.Drvo kao prirodni i obnovljivi materijal ponovo dobiva sve veću vrijednost i sve se češće upotrebljava u graditeljstvu. Upotreba drva poboljšana je zbog primjene suvremenih tehnologija vezanja (npr. lamelirano drvo), razvoja suvremene proizvodne tehnologije i poboljšanih metoda zaštite drva od požara. Budući da je ponuda građevnog drva u obliku laganih greda i ploča na tržištu velika, njime je moguće izvesti stabilne i izdržljive spojeve među pojedinim konstrukcijskim elementima zgrade. Među drvnim materijalima koji se rabe za gradnju sve je zastupljenije unakrsno lamelirano drvo (CLT). Primjenjuje se u izgradnji obiteljskih kuća, stambenih zgrada, višekatnica, javnih zgrada, industrijskih i maloprodajnih zgrada, kao i mostova. CLT je razvijen kao rezultat europskih istraživanja uporabe drvnih elemenata malih dimenzija, preostalih nakon uklanjanja grešaka drva, i to mahom za privatnu gradnju. Trend se vrlo brzo proširio na građevnu industriju u Sjevernoj Americi, Australiji i Japanu. CLT se zbog svoje velike seizmičke otpornosti sve više upotrebljava u višekatnim zgradama. Na početku sada već 30-godišnje povijesti CLT-a uporaba toga građevnog materijala bila je minimalna. Međutim, zbog ekološke prihvatljivosti i širokog spektra ekonomskih čimbenika (cijena upotrijebljenog materijala i troškovi proizvodnje, u kombinaciji s velikom preciznošću gotovih proizvoda) ta je tehnologija postigla veliku popularnost. Osim toga, sve veće zanimanje za drvene konstrukcije rezultat je i boljih distribucijskih kanala te dobivanja tehničkih odobrenja za različite koncepte drvenih građevnih ploča. U proizvodnji i upotrebi CLT-a vodeće su zemlje Austrija, Njemačka, Švicarska, Švedska, Norveška i Ujedinjeno Kraljevstvo. U posljednjih nekoliko godina toj su se skupini zemalja pridružili Novi Zeland i Australija. CLT ploče izvoze se u Sjevernu Ameriku, Japan i Rusiju. Povećanje broja proizvođača i zanimanje ulagača za CLT ploče rezultat je raznolikosti proizvodnih procesa i varijabilnosti gradnje. Stoga postoji sve veći broj koncepata koji određuju raspon primjene proizvoda, ovisno o njegovoj čvrstoći i otpornosti

Kvaliteta i dimenzijski parametri borove građe velikih dimenzija u svjetlu zahtjeva poljske pilanske industrije

Changes in the processing directions of round wood require the selection of raw material with appropriate quality and dimensional characteristics. In the case of large-size pine wood, these parameters translate significantly into its value and material indicators. The purpose of the research was to verify the currently applied classification principles with respect to the expectations of the market of wood industry customers. The research was conducted using the direct survey method, taking into account the structure of processing and sorting of production of wood industry representatives. The basic dimensional and quality groups for coniferous wood were separated, with wood defects assigned to them, in accordance with the currently binding principles of the quality and dimensional classification conducted by the State Forests. The respondents pointed out the necessity of changes in the minimum dimensions for wood of higher quality classes and changes in admissibility of selected defects in wood of lower classes.Promjene u načinu obrade trupaca zahtijevaju odabir sirovine odgovarajuće kvalitete i dimenzija. Kad je riječ o borovoj građi velikih dimenzija, ti parametri znatno utječu na njezinu vrijednost i materijalne pokazatelje. Cilj istraživanja bio je provjeriti trenutačno primjenjive pravilnike o klasifikaciji borove građe s obzirom na očekivanja tržišta drvne industrije. Istraživanje je provedeno metodom izravnoga anketnog ispitivanja predstavnika drvne industrije, pri čemu su uzeti u obzir struktura obrade proizvoda i način proizvodnje. Crnogorično je drvo razvrstano u osnovne dimenzijske i kvalitativne skupine kojima su pridodane greške drva, sukladno trenutačno obvezujućim pravilnicima o klasifikaciji drva prema kvaliteti i dimenzijama što ih provode Državne šume. Ispitanici su upozorili na nužnost promjene minimalnih dimenzija za drvo višeg razreda kvalitete te promjene glede dopuštenih grešaka drva nižeg razreda kvalitete

Problems of Sustainable Transport of Large-Sized Roundwood

When considering the economic and environmental aspects of forestry, especially the issues related to timber harvesting, emphasis should be placed on the importance of the availability of raw material resources for the sustainable flow of goods. It would also be difficult to disregard certain issues related to transport, which play a key role in the efficient flow of wooden raw materials. It has to be noticed that timber transport options are limited by a number of factors, including the considerable fragmentation of wood resources and the lack of adequately developed railway transport facilities. This paper focuses on issues related to the road transport of timber carried out by transport companies. Observations to date of large-sized roundwood (thicker than 14 cm and longer than 3 m) transport in Poland indicate a relatively frequent occurrence of overloaded vehicles, exceeding the permissible total weight limit. Empirical evidence also suggests that in many cases, it is an effect of improperly endorsed standards with regard to the density of the transported material. Moreover, there is a clear correlation between the loading volume and economic as well as environmental factors. Therefore, the aim of this article was to show both the current situation in the transport of bulky timber and to present the possibilities for its optimization, from the point of view of locational, economic and environmental factors. Document type: Articl

Economic, Technological as Well as Environmental and Social Aspects of Local Use of Wood By-Products Generated in Sawmills for Energy Purposes

The article is the first in a series of works presenting the potential and possibilities of using for energy purposes wood waste and wood by-products generated at various stages of production in companies of the wood industry. The management of all wood waste and wood by-products is a pending issue due to the growing importance of the circular economy and broadly understood environmental protection. It is the environmental aspects and the climate targets defined by the EU that are the basis to determine the precise courses of action for the Member States and, as a result, also for companies. The article proves that regardless of the decisions taken by governments of individual countries in terms of broadly understood environmental protection, companies are free to implement pro-environmental solutions as part of their business activity. Due to the broad subject of the management of waste and by-products generated in different units of the wood industry, the possibilities of their use in terms of energy in primary wood processing companies–sawmills—are presented first. On the example of selected entities, the energy potential and possibilities of generating energy from renewable sources taking into account the principles of circular economy are presented. The possibilities of optimising production by improving redistribution of thermal energy, which may result in improving the economic efficiency of the assessed enterprises, were indicated

The Potential of the Bioenergy Market in the European Union—An Overview of Energy Biomass Resources

One of the bases of the European policy and energy strategy is the biomass and bioenergy obtained from it. It is estimated that by 2023, the annual demand for biomass will have increased from the current level of 7 EJ to 10 EJ. There are significant differences between estimates of the bioenergy potential due to the fact that the authors of publications do not use consistent methodology and assumptions. Forest biomass, agricultural residues, and energy crops are the three main sources of biomass for energy production. Energy crops are likely to become the most important source of biomass. Land use and its changes are a key issue in the sustainable production of bioenergy as the availability of biomass determines its potential for energy security. This article is a review of the latest publications on the bioenergy potential of the member-states of the European Union. The consumption of energy and its potential were presented, with a special focus on renewable sources, especially biomass. The potential of biomass resources was presented and the types of biomass and its sources of origin were indicated. The research was conducted on the member-states of the European Union, whose policy is based on long-term development from the dependence on fossil resources to the dominance of renewable resources. As results from the research, in recent years, there has been a significant increase in the potential of both forest biomass (from 4.8 EJ per annum to the forecasted 15 EJ per annum) and agricultural biomass from (from 2.3 EJ per annum to the forecasted 7 EJ per annum). The increase in the demand for energy biomass in the EU member-states is balanced by partial imports from non-EU countries

Economic, Technological as Well as Environmental and Social Aspects of Local Use of Wood By-Products Generated in Sawmills for Energy Purposes

The article is the first in a series of works presenting the potential and possibilities of using for energy purposes wood waste and wood by-products generated at various stages of production in companies of the wood industry. The management of all wood waste and wood by-products is a pending issue due to the growing importance of the circular economy and broadly understood environmental protection. It is the environmental aspects and the climate targets defined by the EU that are the basis to determine the precise courses of action for the Member States and, as a result, also for companies. The article proves that regardless of the decisions taken by governments of individual countries in terms of broadly understood environmental protection, companies are free to implement pro-environmental solutions as part of their business activity. Due to the broad subject of the management of waste and by-products generated in different units of the wood industry, the possibilities of their use in terms of energy in primary wood processing companies–sawmills—are presented first. On the example of selected entities, the energy potential and possibilities of generating energy from renewable sources taking into account the principles of circular economy are presented. The possibilities of optimising production by improving redistribution of thermal energy, which may result in improving the economic efficiency of the assessed enterprises, were indicated

Activity of enterprises in the wood-based sector under conditions of economic uncertainty

Activity of enterprises in the wood-based sector under conditions of economic uncertainty. The state of the epidemic in Poland and the resulting restrictions caused serious disturbances in the economy. Entrepreneurs, conducting business in conditions of economic uncertainty and the threat of a crisis, are looking for various support tools, including adequate government programs. The study attempts to identify and evaluate selected anti-crisis tools, dedicated and possible to be used in the wood-based sector in Poland. The impact of these tools on economic activity was assessed by entrepreneurs, with particular emphasis on the opinions of manufacturers of wooden and cork products, producers of paper and paper products and furniture manufacturers, categorizing industry specializations in accordance with the Polish Classification of Activities. In the comparative analysis, selected economic indicators were used, based on secondary data of public statistics, according to the assessment of the current economic situation and its forecast expressed in the opinion of entrepreneurs. As a result, it was found that despite the ongoing epidemic, entrepreneurs in the wood-based sector relatively often use government support tools, showing moderate optimism under the conditions of economic uncertainty.Działalność przedsiębiorstw sektora bazującego na drewnie w warunkach niepewności gospodarczej. Stan epidemii w Polsce i wynikające z niego ograniczenia wywołały w gospodarce poważne zakłócenia. Przedsiębiorcy, prowadząc działalność gospodarczą w warunkach niepewności gospodarczej i zagrożenia kryzysem, poszukują różnych narzędzi wsparcia, w tym adekwatnych programów rządowych. W pracy podjęto próbę identyfikacji i oceny wybranych narzędzi antykryzysowych, dedykowanych i możliwych do zastosowania w sektorze bazującym na drewnie w Polsce. Wpływ tych narzędzi na aktywność gospodarczą poddano ocenie przedsiębiorców, ze szczególnym uwzględnieniem opinii producentów wyrobów z drewna oraz korka, producentów papieru i wyrobów z papieru oraz producentów mebli, wyodrębniając specjalizacje branżowe zgodnie z Polską Klasyfikacją Działalności (PKD). W analizie porównawczej wykorzystano wybrane wskaźniki koniunktury, bazujące na danych wtórnych statystyki publicznej, odnoszące się do oceny bieżącej sytuacji gospodarczej oraz jej prognozie wyrażanej w opinii przedsiębiorców. W rezultacie stwierdzono, że mimo trwającego stanu epidemii, przedsiębiorcy sektora bazującego na drewnie relatywnie często korzystają z rządowych narzędzi wsparcia, wykazując w warunkach niepewności umiarkowany optymizm

Influence of qualitative and dimensional classification of Pinewood raw material as an efficiency indicator in the production of selected timber assortments

Wood processing plants in Poland are recipients of more than 50% of round wood, which is delivered by the State Forests National Forest Holding. Thus playing a crucial role in the technological processing of raw material for all other wood industry branches. Each group of recipients has individual needs and expectations concerning the quality of the raw material such as, its type and the size of the cross-sections of the assortment used for further production. Therefore, it is economically justified for small production plants to abandon the production of narrow groups of assortments, which usually meets the standards of timber for general purposes. The aim is to make wood processing more flexible and lower the quality of raw material to produce assortments for a specific branches of the wood industry. Wood processing experiments were conducted to produce laths for construction purposes. These materials are one of the most important elements of roof constructions. The research proved empirically that it was possible to produce quality class 1 laths (88% of all laths produced) from WC0 class pinewood used as the input raw material and that the quantitative efficiency exceeded 55%.Wpływ doboru jakościowo wymiarowego surowca sosnowego, jako wskaźnik wydajnościowy w produkcji wybranych sortymentów tarcicy. Zakłady pierwiastkowego przerobu drewna w Polsce są odbiorcami ponad 50% drewna w postaci okrągłej, sprzedawanego przez Państwowe Gospodarstwo Leśne „Lasy Państwowe”. Tym samym odgrywają decydującą rolę na drodze technologicznego przetworzenia surowca dla pozostałych gałęzi przemysłu drzewnego. Każda z grup odbiorców posiada indywidualne potrzeby dotyczące jakości wykorzystywanego surowca, gatunku oraz wielkości przekrojów poprzecznych sortymentu wykorzystywanych do własnej dalszej produkcji. Stąd ekonomicznie uzasadnione jest, odchodzenie mały zakładów produkcyjnych od wytwarzania wąskich grup sortymentów, często zgodnych z normami tarcicy tartacznej ogólnego przeznaczenia. Dąży się do uelastycznienia przerobów i wytwarzanie sortymentów pod konkretną gałąź przemysłu z surowca niższej jakości. Dla celów badawczych przeprowadzone zostały przeroby doświadczalne uwzględniające pozyskanie łat budowlanych. Są to materiały, będące jednym z ważniejszych elementów konstrukcji dachowych. Doświadczalnie oraz empirycznie udowodnione zostało, że w odniesieniu do surowca wejściowego, jakim jest drewno sosnowe klasy WC0, możliwe jest wytwarzanie łat zaklasyfikowanych do I klasy jakości (stanowiącej 88% z wszystkich wytworzonych łat) z wydajnością ilościową przekraczającą 55%

Energy Use of Woody Biomass in Poland: Its Resources and Harvesting Form

Currently, woodchips and logging residues form the greatest share of biomass fuels used to generate heat in combined heat and power plants. They are supplied from various regions of the EU. The calorific values of the wood species used as biomass may vary significantly depending on the moisture and composition of the fuel, harvest seasonality, location, and other factors. This article presents the main resources of forest biomass and its characteristic features, as well as the calorific value of woodchips depending on the moisture content. Our research is based on the source data of forest resources from the State Forests National Forest Holding (PGLLP) in Poland. The research conducted by the main forestry enterprise in Poland covered a period of four years. The data on the harvesting of woodchips and logging residues converted into the calorific values of biomass were based on our research and a review of reference publications. Standard methods were used in the research, which included an analysis of the species and assortment structure of the forest biomass of energetic significance that was available for use. The research showed that the moisture content of the woodchips and lump wood was about 30%. The average annual energy value of the wood in the total area of forest resources was 0.07 GJ/ha, whereas the highest value was 0.14 GJ/ha. Between 2018 and 2021, the average energy resources of forest biomass in Poland increased from 351.8 TJ to 498.4 TJ

Pine Logs Sorting as a Function of Bark Thickness

The process of sorting softwood raw materials is aimed at full automation. Techniques such as laser and optical scanning, used in measuring and sorting wood raw material with the layer of bark, are based on an analysis of the external shape of the log. The consequence of this is the use of constant ranges of bark deductions, which are often affected by errors resulting from averaging the values. The thickness of the bark is influenced by many factors, such as the tree species and the quality of habitat in which the trees have grown. In the case of pine wood, the range of adopted diametral intervals for the processed raw material plays a significant role. The analysis of the automatic sorting results showed numerous cases of a log-size mismatch. In methods that assume the measurement of wood with the bark, deductions for bark should be made based on experiments that take into account the raw resources base. Despite the high correlation between the size of the deduction and the average thickness of the bark (r = 0.85), the mean value of an error of the adjustment to the maximum thickness of the bark in the automatic sorting was 45%. The maximum bark thickness for the analyzed sorting intervals was correlated. The level of the correlation coefficient value was r = 0.72. In order to increase the accuracy of the sorting process, the value of the deduction for bark should be adjusted to the maximum values in each sorting group