The Lifespans of Products Made with MDF Irie, M.; Lebreton, F.; Kutter, M.
Bulletin of the Transilvania University of Brașov. Series II, Forestry, wood industry, agricultural food engineering,
2023, Volume:
16
Journal Article
Open access
The Horizon Europe funded EcoReFibre project (www.ecorefibre.eu) is concerned with recycling fibreboards and, in particular, Medium Density Fibreboard. This paper covers our research on determining ...the typical lifespans of products containing fibreboard. Knowing the lifespan of a product is important as it is the main determining factor that influences the age when it becomes waste. This paper proposes that the average age at which a product containing MDF becomes waste is between 10.7 and 12.1 years.
Quercus cerris (Turkey oak) has been categorized as a drought-tolerant species because it can survive with rainfall below 400 mm/year, and it usually develops deep and penetrating taproots. This ...characteristic suggests that Turkey oak is a survival candidate species for the future environment with the predicted climate scenarios in Hungary. Potentially, Turkey oak could support a sustainable supply of timber to the Hungarian wood industry in the future, as the aesthetic value is similar to that of noble oaks. The objectives of the study are to determine 1; the selected micro-level wood properties (wood tissue characteristics) and 2; the selected macrolevel wood properties (tree-ring width, sapwood-heartwood ratio) for Turkey oak from two different sites. The heartwood portion for all trees constituted 67-82% of the cross-diameter. The growth-ring width decreased from pith to bark. The annual rings in the sapwood had a width value range of 1000 to 1600 μm; in heartwood 1600 to 2500 μm; in juvenile wood 2400 to 3300 μm. Soil quality and stand composition had a significant effect on growth-ring width. Fibre length ranged from 800.03 to 1305.59 m, whereas fibre-wall thickness varied between 11.73 and 18.51 μm, with soil quality and species composition having a highly significant influence. The earlywood parts of the growth rings had a vessel diameter range of 274.62-401.54 μm, whereas the latewood portion ranged from 46.50 to 190.08 μm. Overall, stand composition was a major source of variation in the properties studied.
Particleboards are the main material used in the production of furniture and furnishings. The shortage of wood raw material and the everincreasing amount of particleboards produced suggest a search ...for alternative raw material sources for this panel type. On the other hand, significant quantities of agro-industrial lignocellulosic residues are available worldwide. Such a type of residue is hemp shives. Basic joints in furniture frames are stapled joints, as it should be said that density is the main characteristic of particleboards, and their other properties strongly correlate with it. The present research studies the influence of the density of panels from hemp shives on their staple withdrawal resistance. For this purpose, panels from hemp shives with melamine-formaldehyde (MF) resin as an adhesive and densities from 600 kg.m-3 to 900 kg.m-3 were produced in laboratory conditions. The density of the panels varied with a step of 100 kg.m-3. As a result of the research, it was found that the staple withdrawal resistance of hemp shives particleboards from the edge and side of the panels increases almost twice with the increase of their density. It was also found that, unlike industrial particleboards, edge staple withdrawal resistance is higher in hemp shive panels than side staple withdrawal resistance. Laboratory-produced panels from hemp shives have a higher staple withdrawal resistance at similar densities than industrial particleboards. However, this is at the expense of using expensive MF resin and the significantly extended press factor. The main novelty of the research is the establishment of the effect of the density of hemp shive particleboards on their staple withdrawal resistance, as well as the demonstration of the possibility of producing panels from an alternative lignocellulosic raw material with a better staple withdrawal resistance than that of industrial particleboards manufactured from wood raw material.
Organic phase change materials (PCMs) offer a promising approach to improving the energy efficiency and sustainability of buildings. Impregnating wood with PCMs presents the opportunity for its ...application in building construction to reduce energy consumption for heating and cooling of indoor spaces. In this study, the process of solid wood impregnation with PCMs was conducted, along with the characterisation of their thermal properties. To define an optimal melting point and quantity to be incorporated into test cubes exposed outdoors for long term in Kuchl (Austria), a digital model was used to simulate beech and spruce that were impregnated with PCMs featuring two differing melting points. The results show that incorporating PCM into walls and floor can potentially reduce summer overheating by up to 48%. This effect is achieved using a building design that includes wood impregnated with PCM with a lower melting point of around 21°C. However, the building design and use of the employed PCMs do not reduce energy consumption for heating during winter. The results show that the performance is strongly dependent on the melting point of the PCM and its quantity in the building. These findings contribute to improving the design of the experimental test cube with impregnated wood and highlight the challenges.
By choosing suitable individual building materials for a sandwich structure, we can ensure an increase in the fire resistance of the entire structure. The influence of the properties of individual ...building materials on the overall fire resistance in sandwich constructions has not been well researched. It is for this reason that we focus our contribution on the influence of the properties of building materials in wooden sandwich structures on overall fire resistance. In the wooden sandwich constructions we created, we worked with reference constructions composed of thermal insulation with different surface treatments and with constructions that have the same thermal insulation, but we added 40 mm thick mineral wool to them. Subsequently, we tested the structures according to the EN 1365-1 standard 4. After processing the obtained results, we came to conclusions about the effect of mineral wool and its combination with suitable thermal insulation on overall fire resistance.
The purpose of the research was to study the usability of coconut flour in Easter cake recipes to improve consumer properties and increase nutritional value. It has been established that the ...replacement of 10% of wheat raw materials with coconut flour and a decrease in the amount of margarine by 28% in Easter cake recipes allow us to obtain products with good consumer properties, increased content of mineral elements – selenium (by 58.3%), iron (by 13.3%), magnesium (by 9.1%), copper (by 5.5%) and coarse fibers (by 6.6%), and a reduced amount of gluten and trans fatty acid isomers.
The cucumber (Cucumis sativus L.) is an economically important vegetable crop cultivated worldwide, including Vietnam. This study aims to determine the physiological ripening time of cucumber fruit ...to establish a scientific basis for optimizing fruit quality, harvest, and preservation. Changes in the physiological and biochemical parameters during the growth and development of cucumbers from 2 to 12 days after anthesis (DAA) were observed and analyzed. The fruit reached its maximum size in length, diameter, volume, and weight at 11 DAA. The chlorophyll content of the fruit reached its maximum value at 8 DAA and then decreased. The carotenoid content was low during fruit formation and increased until fruit ripening. The vitamin C content and reduced sugar content increased continuously and reached a maximum of 11 DAA before decreasing slightly. The starch content, total organic acid content, and tannin content reached a maximum of 9 DAA and then gradually decreased. The pectin content increased from fruit formation until fruit ripening. Our results indicate that cucumbers should be harvested at 11DAA to maximize the nutritional value of the fruit for consumption and processing.
The article is devoted to the effect of pretreatment with a solution of carrageenan on the enzymatic activity of cherry fruits in the period of storage. For the purpose of research between 2019-2020, ...the fruits of the Alpha and Pamiat of Artemenko cherry varieties of the same color were selected, sorted, washed, and dried, covered with a solution that included carrageenan (1−2 g/100 ml of solution), glycerin (0.6 g/100 ml of solution) according to the options: without treatment (control) and treated with carrageenan solutions of 1% and 2% concentration. Cherry fruits were immersed in a pre-prepared solution, kept for 1-2 minutes, removed, allowed to drain, and dried at the flow of air created artificially by a fan. Experimental and control samples of fruits were placed in boxes and stored at a temperature of 1.0±0.5° C and relative humidity of 95.0±1.0%. The most effective was the treatment of cherry fruits with a 2% solution of carrageenan, which made it possible to reduce the activity of antioxidant enzymes catalase by 38.5–35.7% and superoxide dismutase (SOD) by 9.5−11.1%. Between the antioxidant enzymes (CAT, SOD, APX) of cherry fruit, close correlations (r = 0.86, r = 0.82) were established and the regression equation was derived.
Bio-based commercial coating systems are still not widely used to protect wooden elements and constructions used outdoors. In some cases, this is due to insufficient information about the technology ...and conditions of the film formation process. The present research aims to determine the influence of the process conditions on the properties of a coating applied by dipping on spruce, beech, and beech plywood surfaces. A waterborne one component bio-based varnish system was used. The study researched the following parameters: the amount of varnish applied, varnish penetration into the wood, and roughness of the surfaces after coating and drying. The variables investigated were the dipping orientation to the grain direction in the wood specimens, the wood surface treatment before coating, and the dipping time. Polynomial regression models were derived. It was established that with a single dip for 5 seconds, surfaces with a good appearance were obtained, but the varnish amount exceeded the norms recommended by the manufacturer several times. When axially dipping spruce and beech specimens, the varnish amount was the least when the surfaces were sanded with P150 grit-sized sandpaper. For the plywood specimens, the treatment had no effect. In tangential dipping, the characteristics of the wood species determined the varnish amount and the roughness parameter values. The sanding process had a more significant influence than the sandpaper grit size. The penetration was affected by the wood species characteristics, the wood surface treatment before coating, and the dipping time. In axial dipping, the penetration was times greater than in tangential dipping.
For a circular and sustainable economy, the reuse of wood furniture parts has gathered increasing importance. Disassemblable joints and purposefully developed elements may support this reuse. Despite ...the relatively high number of structural connectors, newly developed fittings have appeared on the market, combining the advantages of the previous ones or introducing new solutions, like the Domino dowels and connectors developed to make strong hidden joints. In furniture manufacturing, both panel and frame elements are joined for load-bearing, semi-load-bearing, or non-load-bearing connections. Metallic Domino connectors have recently been developed and recommended by the manufacturer only as connecting elements, and not as supporting elements of furniture constructions. In daily practice, the general consideration exists that these metallic connectors are strong enough to perform well as load-bearing elements. The main goal of this research was to examine the strength of corner (L) and T joints made with upper wood dowels and metallic connectors, to compare their performance. For the experiments, same-sized wood dowels and metallic connectors were used. The tension and compression test results indicate that the type of joint (corner versus T) is a stronger influencing factor of performance than the type of jointing element (wood dowel vs. metallic connector). Domino dowels are manufactured in different sizes. Further research will focus on finding the wood dowel equivalent to a given metallic connector of different sizes.
