Effect of printing layer thickness on technological properties of 3D-printed specimens fabricated from wood flour/PLA filaments having a diameter of 1.75 mm was investigated. For this aim, four ...different printing layers, 0.05 mm, 0.1 mm, 0.2 mm, and 0.3 mm, were used in the production of the 3D-printed specimens. The water absorption of the specimens (28 days immersion in water) increased with increasing printing layer thickness while the thickness swelling decreased. The tensile and bending properties of the specimens significantly improved with decreasing printing layer thickness. The increase in the layer thickness caused bigger gaps, which increased the porosity in the cross section of the specimen. Higher porosity resulted in lower mechanical properties.
From a climate perspective, it could be advantageous to increase the use of wood products in buildings, but the use of sawn timber and engineered wood products (EWPs) in multi-storey buildings above ...two floors are a relatively new business (in Sweden since 1995) and there is a risk that wood as construction material is met with low awareness and high uncertainty by the construction sector. The purpose of this study was twofold: 1) to learn Swedish architects' views of using EWPs in buildings, and 2) to identify parameters that positively influence the likelihood that EWPs will be selected to a greater extent and the relative importance of those parameters.
A survey was sent out to Swedish architects and 67 answers were received. The result indicates that architects in Sweden have a positive attitude towards EWPs in general and that the majority think that they will probably increase their use of these materials. Low impact on the environment, aesthetic appeal, and fast construction were the most common reasons stated for selecting EWPs. The Swedish architects have in general a moderate impact on the selection of materials, and the most common reason for not selecting EWPs was that other decision makers involved in the building projects prefer other materials. A lack of knowledge and information as well as uncertainties regarding the quality over time were other common reasons for not selecting EWPs.
It was found that architects who had participated in building projects where EWPs had been chosen due to their low environmental impact and/or aesthetic appearance were more likely to state that they will increase their use of EWPs. The results also show that influence on material selection, knowledge of EWPs, experience of the use of EWPs, and the architect's own attitude to the use of EWPs affect the likelihood of an increased use.
•Swedish architects have potential to be good advocates for increased use of EWPs.•Supposedly low environmental impact - most common reason for selection of EWPs.•Other actors prefer other materials – most common reason for not selecting EWPs.•There is a need to increase the architects' knowledge of engineered wood products.
Wood-products value-chain mapping Mo, Jue; Haviarova, Eva; Kitek Kuzman, Manja
Wood material science and engineering,
07/03/2024, Volume:
19, Issue:
4
Journal Article
Peer reviewed
Open access
With the increasing importance of wood as a sustainable material and addressing challenges facing the wood products industry, there is an emerging need for innovation and collaboration across all ...industry sectors. The mapping of the wood products industry has become crucial for gaining an overview and overall understanding of material flow. It also proved beneficial for educational and research purposes. The outcome of this study should help seek new economic opportunities and promote sustainable resource management. A
Generic Map
was developed to navigate the entire wood products industry as well as
Dive-in Chain Maps
will guide the four major production chains: sawmill (I), veneer mill (II), reconstituted wood manufacturing (III), and pulp and paper mills (IV). In addition, a
By-products Management Wheel Diagram
was introduced to clarify waste management practices within these chains. Our approach sheds light on efficient material flow and utilization, revealing opportunities for innovation and the development of high-value products. It also offers strategies for minimizing waste and making informed end-of-life decisions. Ultimately, this study enhances the understanding and potential for circularity and sustainability in the wood products industry.
This study aimed to understand the effects of core configuration on the mechanical properties of additively manufactured specimens made of commercial wood/PLA filament through 3D printing. The ...wood/PLA specimens with different infill rates and pattern types, such as square, hexagonal, and octagonal, were manufactured using a 3D printer. The process parameters in the production of the 3D-printed specimens were kept constant, except for the core configuration. The outside layer thickness was kept constant for all the specimens. The specimens with a hexagonal pattern had the highest mechanical properties, followed by the square and octagonal core patterns. In terms of infill rate, the mechanical properties sharply increased with increasing infill rate. In particular, when the infill rate increased from 20 to 50%, the rate of increase in the mechanical properties was significantly higher than that seen from 50 to 80%. The highest rate of the elastic recovery after the Brinell hardness tests was found in the specimens with hexagonal cores, followed by square- and octagonal-shaped cores.
Amount of wood flour was gradually increased from 0 to 50 wt% in the production of polylactic acid (PLA) based filaments with 1.75 mm diameter using twin screw extruder. Surface roughness and ...wettability were measured of the specimens. Surface roughness of the specimens significantly increased with incorporation of wood flour into PLA filament. Wettability of the specimens significantly decreased with increasing wood flour content. This was mainly attributed to the higher surface free energy of PLA than the beech wood. Contact angle values of the 3D printed wood/PLA specimens having wood flour content up to 30 wt% were less than 90°.
Monitoring consumer buying behaviors in terms of their preferences and attitudes has been known as an important driver for the success and development of various industries, including a wood ...furniture manufacturing. The aim of this study was to identify and compare the purchasing behaviors of furniture consumers in the period before and during the COVID-19 pandemic. Two surveys were conducted in Croatia, the first in April and May 2020 with the assumption that consumer purchasing behaviors will change during the COVID-19 pandemic in the following year and the second one during March 2021. Differences regarding consumer purchasing behaviors and preferences for wood furniture between respondents regarding demographic and economic factors before and during the pandemic were found. The coronavirus pandemic is teaching us all hard lessons about resilience and adaptability, and new opportunities and solutions are essential. Nowadays, it is becoming increasingly important to produce information. Research offers insights into future design and building communication to better meet the information needs of different types of consumers and to more broadly increase the acceptance and appeal of wood furniture in society in the spirit of sustainable and bio-based circular economy.
•Architect perceptions of engineered wood products in Europe countries were studied.•A positive perception regarding the use of wood in general in all countries.•A lack of knowledge of principles of ...design options with EWPs.•The internet is the leading source of information used by architects.•There is a need for more technical information to understand the potential of EWPs.
The wood industries in Slovenia, Croatia, Bosnia and Hercegovina (BiH) and Macedonia have a long tradition of producing a wide range of products. BiH and Macedonia have similar forest sectors and both countries have experienced similar problems in the manufacturing, sale and use of wood-based products in recent years due to the global financial crisis and resulting national economic challenges. Despite having a long and prosperous history, over the past two decades, the wood products sectors in these four countries have faced a steady decline in profitability, the ability to add value through downstream manufacturing, and overall competitiveness.
Engineered wood products (EWPs) are structural building materials that have been used since the early 1980s as replacements for, or in conjunction with, concrete and steel. In this study, we compare architect attitudes, awareness and preferences regarding the use of EWPs between these four countries. The study is based on a sample of 373 architects using on-line surveys. Results suggest that there is a positive perception regarding the use of wood in general in all countries, with the majority of respondents believing that wood use will increase in the future. However, specific to EWPs, differences were found in familiarity and knowledge of potential applications in timber-based construction. Results provide indicators of knowledge gaps between respondents and, conversely, where awareness and willingness to use EWPs exist. These findings can have implications for market opportunities, identifying barriers to EWPs adoption, and content for workshops, seminars, and other outreach mechanisms for architects.
This paper investigated the bending moment of chair base joints. The ultimate bending moments (maximum moment), calculated on the base of the measured maximum applied loads (maximum force), were ...compared for the front leg and rear leg joints of a chair base. The joints had different angles between the stretcher and the leg (joint angle) as well different tenon lengths (30 mm and 32 mm). The results of the tests indicated that for different test specimen configurations but the same tenon-and-mortise geometry, the maximum force of joints with a smaller value of joint angle (front leg joints) was higher than the force values of joints with a larger angle (rear leg joints) for all tenon lengths. However, the results showed less difference among the calculated bending moments of the analysed sets of joints. A significant difference was not revealed between the bending moments of joints with a smaller value of joint angle and the bending moments of joints with a larger angle for all tenon lengths. A significant difference between the bending moments for the tenon length of 30 mm and tenon length of 32 mm was determined for rear leg joints but not for front leg joints. The presented approach of joint strength analysis through the testing of specimens with different shapes and dimensions are applicable to research and practice.
U radu je proučavan moment savijanja spojeva na križnoj potkonstrukciji sjedala stolice. Krajnji momenti savijanja (najveći moment), izračunani na temelju izmjerenih najvećih opterećenja (najveća sila), uspoređeni su za spojeve prednjih i stražnjih nogu križne potkonstrukcije sjedala stolice. Spojevi su imali različite kutove između poveznika i noge (kut spoja), kao i različitu duljinu čepova (30 i 32 mm). Rezultati ispitivanja pokazali su da je za različitu konfiguraciju ispitnih uzoraka, ali za istu geometriju čepa i rupe, najveća sila bila veća za spojeve s manjim kutom (spojevi prednjih nogu) nego za spojeve s većim kutom (spojevi stražnjih nogu), i to za čepove obiju duljina. Rezultati su također pokazali manju razliku između izračunanih momenata savijanja analiziranih grupa spojeva. Nije utvrđena značajna razlika momenata savijanja spojeva s manjim i većim kutom za čepove obiju duljina. Značajna razlika između momenata savijanja za čepove dužine 30 i 32 mm utvrđena je za spojeve stražnjih nogu, ali ne i za spojeve prednjih nogu stolice. Prikazani pristup analize čvrstoće spojeva ispitivanjem uzoraka različitih oblika i dimenzija primjenjiv je u istraživanju i u praksi.
The influence of artificial ageing on bonded heat-treated spruce lamellas was investigated. Heat-treated spruce lamellas with different degrees of thermal modification were bonded with PVAc and MUF ...and then exposed to 500 artificial weathering cycles, combined with rain, UV and IR radiation. The colour change of the exposed surface, weight change, delamination of the bonded joints and adhesive bond strength were measured. Artificial weathering caused cracking and delamination of the bonded joints and reduced the bond strength of both adhesives. The results show that delamination was higher for PVAc adhesive than MUF, but increased for both adhesives with the temperature of heat treatment of wood. The shear strength of bonds on the exposed side of the samples after the artificial weathering was lower than the average strength of the whole sample.
U radu je istražen utjecaj umjetnog starenja na lijepljene lamele toplinski modificirane smrekovine. Lamele toplinski modificirane smrekovine različitih stupnjeva toplinske modifikacije lijepljene su PVAc i MUF ljepilom, a zatim su tijekom 500 ciklusa izložene vremenskim utjecajima u kombinaciji kiše te UV i IR zračenja. Mjerena je promjena boje izložene površine, promjena mase te delaminacija i čvrstoća lijepljenog spoja. Umjetno izlaganje vremenskim utjecajima uzrokovalo je pucanje i delaminaciju lijepljenih spojeva te smanjenje čvrstoće spoja lijepljenog obama ljepilima. Rezultati pokazuju da je delaminacija bila veća na slojevima s PVAc ljepilom nego na slojevima lijepljenim MUF ljepilom, ali je povećana na slojevima s oba ljepila, uz povećanje temperature toplinske modifikacije drva. Nakon umjetnog izlaganja vremenskim utjecajima smična je čvrstoća lijepljenog spoja na izloženoj strani uzoraka bila niža od prosječne čvrstoće cijelog uzorka.
In recent years, additive manufacturing has become a regular process in various industries, and consequently there is an increasing need to evaluate the environmental aspects of this technology and ...its associated materials. In this paper, comparative cradle-to-grave life cycle assessments between a conventional product and a 3D-printed alternative made of polylactic acid (PLA) and PLA-wood material were investigated based on the standard ISO 14044:2006. The environmental impact of each product was quantified for 18 categories. The goal of life cycle assessment (LCA) was to determine whether the use of 3D printed PLA/PLA-wood products can be a sustainable alternative to traditional metal products. The paper presents a case study in which a comparative LCA was conducted. The results show that a metal part manufactured using conventional subtractive processes (milling, drilling, welding, etc.) has a higher environmental impact compared to 3D-printed alternatives made from renewable materials. However, there are many sub-issues that need to be adequately addressed.
Posljednjih je godina aditivna proizvodnja postala redoviti proces u raznim industrijama, a posljedično se pojavila sve veća potreba za procjenom ekoloških aspekata te tehnologije i s njom povezanih materijala. U ovom su radu ispitane i uspoređene procjene životnog vijeka konvencionalnog proizvoda „od kolijevke do groba” te 3D isprintane alternative izrađene od polilaktične kiseline (PLA) i PLA-drvnog materijala na temelju standarda ISO 14044:2006. Utjecaj svakog proizvoda na okoliš kvantificiran je unutar 18 kategorija. Cilj procjene životnog vijeka takvih proizvoda (LCA) bio je utvrditi može li uporaba 3D printanih PLA/PLA-drvnih proizvoda biti održiva alternativa tradicionalnim metalnim proizvodima. U radu je prikazana studija slučaja u kojoj je provedena komparativna procjena životnog vijeka – LCA. Rezultati pokazuju da metalni dio proizveden primjenom konvencionalnih subtraktivnih procesa (glodanja, bušenja, zavarivanja itd.) ima veći utjecaj na okoliš nego 3D isprintane alternative izrađene od obnovljivih materijala. Međutim, u vezi s tim postoje i mnoga potpitanja koja se moraju adekvatno riješiti.
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