scholarly journals Effect of Panel Moisture Content on Internal Bond Strength and Thickness Swelling of Medium Density Fiberboard

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 114
Author(s):  
Roberto Magalhães ◽  
Beatriz Nogueira ◽  
Samaritana Costa ◽  
Nádia Paiva ◽  
João M. Ferra ◽  
...  
Keyword(s):  
Moisture Content ◽  
Bond Strength ◽  
Internal Bond ◽  
Room Temperature ◽  
Medium Density Fiberboard ◽  
Internal Bond Strength ◽  
Medium Density ◽  
Thickness Swelling ◽  
European Standard ◽  
Test Pieces

Wood-based products usually have serious limitations concerning contact with water, both because wood is a hygroscopic material and because the commonly used binder has low moisture resistance. This paper studies the effect of panel moisture content (MC) on the physico-mechanical properties of medium density fiberboards (MDF). Several commercial MDF boards produced in Europe were stored at room temperature and relative humidity (RH) for 9 weeks (approx. range 15–20 °C and 50–85% RH). Every week, a strip of each MDF board was cut out, divided into 5 × 5 cm test pieces and its internal bond strength (IB) was measured. A strong influence of MDF moisture content on internal bond strength was observed and therefore IB test pieces were stored in a climatic chamber (either at 20 °C, 55% RH and at 20 °C, 70% RH). A decreasing linear relation was established between IB and MC. It was found that this effect is reversible: after drying, internal bond strength rises again (following a slight hysteresis). This work reinforces the importance of conditioned storage before board properties analysis, as described in European Standard EN 319.

scholarly journals Some advantages of three-layer medium-density fibreboard as compared to the traditional single-layer one

2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Turgay Akbulut ◽  
Nadir Ayrilmis
Keyword(s):  
Bond Strength ◽  
Internal Bond ◽  
Single Layer ◽  
Middle Layer ◽  
Resin Content ◽  
Internal Bond Strength ◽  
Medium Density ◽  
Medium Density Fibreboard ◽  
Uf Resin ◽  
Layer Medium

Abstract The aim of the study was to develop three-layer medium-density fibreboard (MDF) manufacture by adding the coarse fibres in the middle layer, like three-layer particleboard. The liquid urea–formaldehyde (UF) resin was reduced from 10.5 to 6.5 wt% in the middle layer of the MDFs. The UF resin content was kept constant at 10 wt% in the surface layers of all the MDFs. Moreover, the average density of MDFs was decreased from 730 to 650 kg/m3. The internal bond strength of three-layer MDFs decreased with decreasing UF resin content (10.5 to 8.5 wt%) in the middle layer. However, the decreases in the internal bond strength were statistically not significant. The internal bond strength values of the MDFs having density between 730 and 675 kg/m3 did not show significant differences. The cost savings of the resin were 20% when the amount of resin was reduced from 10.5 to 8.5 wt%. Three-layer MDFs had lower resin consumption at lower densities over traditional single-layer MDFs produced in the same plant with the same material components without decreasing their technological properties. In conclusion, it can be said that three-layer MDF could be produced at a lower cost than traditional single-layer MDF.

scholarly journals Potential Use of Wollastonite as a Filler in UF Resin Based Medium-Density Fiberboard (MDF)

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1435 ◽  
Author(s):  
Hamid R. Taghiyari ◽  
Ayoub Esmailpour ◽  
Roya Majidi ◽  
Jeffrey J. Morrell ◽  
Mohammad Mallaki ◽  
...  
Keyword(s):  
Bond Strength ◽  
Internal Bond ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Medium Density ◽  
Environmental Footprint ◽  
Positive Effects ◽  
Uf Resin ◽  
Resin Curing ◽  
Potential Use

Urea-formaldehyde (UF) resins are primary petroleum-based, increasing their potential environmental footprint. Identifying additives to reduce the total amount of resin needed without adversely affecting the panel properties could reduce these impacts. Wollastonite is a mineral containing calcium and silica that has been used as an additive in a variety of materials and may be useful as a resin extender. Nanoscale wollastonite has been shown to enhance the panel properties but is costly. Micron-scale wollastonite may be a less costly alternative. Medium-density fiberboards were produced by blending a hardwood furnish with UF alone, micron-sized wollastonite alone, or a 9:1 ratio of UF to wollastonite. Panels containing of only wollastonite had poor properties, but the properties of panels with 9:1 UF/wollastonite were similar to the UF-alone panels, except for the internal bond strength. The results suggest that small amounts of micron-sized wollastonite could serve as a resin extender. Further studies are suggested to determine if the micron-sized material has similar positive effects on the resin curing rate.

scholarly journals Selected Properties of Overlaid Magnesium Based Composite Panels for Flooring

2020 ◽  
Vol 10 (15) ◽  
pp. 5028
Author(s):  
Fidan Aslanova ◽  
Gozen Elkiran ◽  
Salim Hiziroglu ◽  
Serkan Ilseven
Keyword(s):  
Bond Strength ◽  
Surface Quality ◽  
Internal Bond ◽  
Internal Bond Strength ◽  
Sample Type ◽  
Thickness Swelling ◽  
Mechanical And Physical Properties ◽  
Flooring Materials ◽  
Flooring Material

The objective of this work was to evaluate some of the mechanical and physical properties of the flooring materials manufactured from panels having magnesia substrate overlaid with oak veneer (Querqus alba) and linoleum sheets. Commercially manufactured panels were used in this work. Bending characteristics, internal bond strength, thickness swelling, and surface quality of the samples were evaluated. The highest modulus of elasticity (MOE) value of 4406 MPa for the sample type-A2 was loaded in the direction of the substrate followed by 3478 MPa for linoleum covered samples which were loaded in the same direction. Internal bond strength values of the panels did not show any significant differences from each other. Dimensional stability of the specimens in the form of thickness swelling for both 2-h and 24-h water soaking tests resulted in values ranging from 0.11 to 0.19%. The surface quality of the samples was not substantially influenced as a function of water exposure. Based on the results in this work magnesium substrate overlaid with oak veneer and linoleum panels could have potential to be used as flooring material with accepted properties.

scholarly journals AVALIAÇÃO DAS PROPRIEDADES FÍSICAS E MECÂNICAS DE PAINÉIS DE FIBRAS DE MÉDIA DENSIDADE (MDF) PRODUZIDOS PELAS INDÚSTRIAS BRASILEIRAS

FLORESTA ◽  
2010 ◽  
Vol 40 (2) ◽  
Author(s):  
Luciane Paes Torquato ◽  
Setsuo Iwakiri ◽  
Ghislaine Miranda Bonduelle ◽  
Carlos Eduardo Camargo de Albuquerque ◽  
Jorge Luís Monteiro de Matos
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Internal Bond ◽  
Medium Density Fiberboard ◽  
Wood Fiber ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
European Standard ◽  
Pine Wood ◽  
Minimum Requirements

Este trabalho foi desenvolvido com o objetivo de avaliar a qualidade de painéis MDF produzidos pelas indústrias brasileiras com base nos resultados de propriedades físicas e mecânicas dos painéis tipo “standard” com 15 mm de espessura. Foram selecionadas quatro empresas produtoras de painéis MDF, que foram identificadas pelas letras A, B, C e D. Para as avaliações das propriedades dos painéis, foram, coletadas para todas as empresas, três painéis-amostras produzidos com madeira de pinus, além de painéis de eucalipto para a empresa D. As propriedades avaliadas foram: teor de umidade, densidade, perfil de densidade, absorção de água e inchamento em espessura 2 e 24 horas, ligação interna e flexão estática. Os ensaios foram realizados de acordo com a norma europeia EM, e os resultados foram comparados com os requisitos da norma EN 622-5:2006. Os painéis produzidos com madeira de eucalipto apresentaram valores médios inferiores de ligação interna e média de absorção de água maior que os obtidos com painéis de pinus. Os valores médios de inchamento em espessura 24 horas, MOE e MOR em flexão estática paralela dos painéis MDF comerciais avaliados nesta pesquisa atendem aos requisitos mínimos da norma EN 622-5:2006. Os valores médios de ligação interna foram inferiores em relação aos requisitos dessa norma. Palavras-chave: Painéis MDF; pinus; fibras de madeira.   Abstract Evaluation of physical and mechanical properties of medium density fiberboard (MDF) manufactured from brazilian industries. This research was developed to evaluate the quality of MDF manufactured by brazilian industries based on the results of physical and mechanical properties of the standard boards with 15 mm thickness. Four factories were selected and identified as A, B, C, and D. For the evaluation of the board properties, they were collected from the all factories three samples produced by pine wood, besides of sample produced by eucalipto wood to the factory D. The following board properties were evaluated: moisture content, density, density profile, water absorption and thickness swelling 2 and 24 hours, internal bond and static bending. The tests were carried out according to European Standard EN and the results were compared with the requirements of European Standard EN 622-5:2006. The boards manufactured from eucalipto wood showed lower average values of internal bond and higher water absorption in comparison to boards manufactured from pine wood. The average values of thickness swelling after 24 hours water soaking, MOE and MOR parallel static bending of the commercial MDF evaluated in this study attends to minimum requirements of EN 622-5:2006. The average values of internal bond were lower than in relation to the EN standard.Keywords: MDF; pine; wood fiber.

scholarly journals Influence of Adding Offcuts and Trims with a Recycling Approach on the Properties of High-Density Fibrous Composites

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1327
Author(s):  
Conrad M. Sala ◽  
Eduardo Robles ◽  
Grzegorz Kowaluk
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Water Absorption ◽  
Internal Bond ◽  
High Density ◽  
Raw Material ◽  
Internal Bond Strength ◽  
Fibrous Composites ◽  
Thickness Swelling ◽  
Linear Decrease

The sizeable global production of wood-based products requires new sources of raw material, but also creates large quantities of wastes or composites that do not comply with requirements. In this study, the influence of different shares of recovered high-density fiberboards (HDF-r), reversed into the production, on industrial HDF properties, has been examined. HDF-r may be a suitable partial substitute for raw pinewood for industrial HDF production. Although most of the mechanical properties, as well as thickness swelling and water absorption, had a linear decrease with the increase in the share of HDF-r share, the elaborated boards met most of the commercial requirements (EN 622-5). The property that did not meet the requirements was the internal bond strength for panels with 10% of HDF-r. The presented results show that, after some adjustments, it should be possible to produce HDF boards with up to 10% of recycled HDF being able to meet all commercial requirements.

scholarly journals Application of African Couchgrass in Manufacturing of Medium Density Fiberboard

2020 ◽  
Vol 10 (3) ◽  
pp. 211-218
Author(s):  
Leopold Mbereyaho ◽  
Line Nzayisenga ◽  
Ernest Tuyizere ◽  
Faustin Hagenimana
Keyword(s):  
Moisture Content ◽  
Material Properties ◽  
Building Material ◽  
Medium Density Fiberboard ◽  
Medium Density ◽  
Thickness Swelling ◽  
Renewable Biomass ◽  
New Material ◽  
Standard Values ◽  
Tree Cutting

AbstractWorldwide, the medium density fiberboard (MDF) materials have been extensively used for furniture as well as a normal building material. The MDF production is based on wood materials that are obtained from the tree cutting, and this process may conduct to gradual deforestation. Different works have shown the advantages of using other renewable biomass sources for MDF manufacturing. This study aimed at assessing the potential of using the African couchgrass, as one of worldwide available grass, and which has been one of the most worrying weeds for agriculture areas. The test with the manufactured MDF checked such material properties like density, moisture content, water absorption, and thickness swelling. The established results were 727.143 kg/m3, 5.81%, 9.18%, and 7.6% respectively. All those results are in the range of standard values recommended by ASTM D1037, and they give optimism for the application of couchgrass in the manufacturing of MDF. This new material was planned to be used as a partition component. Therefore, further studies should evaluate other important properties, like fire and sound resistance, while a proposal for potential replacement of the used industrial wood glue is also welcome.

scholarly journals EFFECTS OF POLYMER ADDITIVES ON SOME MECHANICAL AND PHYSICAL PROPERTIES OF CEMENT BONDED PARTICLEBOARDS

Wood Research ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 331-340
Author(s):  
HASAN HÜSEYİN TAŞ ◽  
BİLGE ARSLAN ◽  
HÜLYA KALAYCIOĞLU
Keyword(s):  
Bond Strength ◽  
Water Absorption ◽  
Internal Bond ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Bending Stiffness ◽  
Internal Bond Strength ◽  
Polymer Additives ◽  
Thickness Swelling ◽  
Cement Mixture

The effects of some polymer additives, also called super plasticizers, on selected physical and mechanical properties of cement bonded particle board were investigated. Two different kinds of poly carboxylic ether (PF300, DX40) and a melamine based polymer (300M) were added to the wood cement mixture. The ratios of polymer additives to the wood cement mixture were 1%, 1.2% and 1.4%. Cement bonded particleboards were manufactured with wood/cement (w/w) ratio of 1:3; target density of 1300 kg.m-3, and CaCl2 content of 5%. The cement bonded particleboards were tested for water absorption (2 and 24 hour), thickness swelling (2 and 24 hour), bending stiffness and strength and internal bond strength. Results of the study showed that most of the polymer addition decreased water absorption and thickness swelling of the boards. Replacement of cement with polymers increased internal bond strength and bending stiffness of the boards while bending strength was slightly reduced. Use of small amount of super plasticizers significantly improves most of the board properties.

Mechanical and formaldehyde-related properties of medium density fiberboard with zeolite additive

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7918-7932
Author(s):  
Osman Camlibel
Keyword(s):  
Internal Bond ◽  
Medium Density Fiberboard ◽  
Formaldehyde Emission ◽  
Wood Chips ◽  
Medium Density ◽  
Wood Fibers ◽  
Thickness Swelling ◽  
Fiber Production ◽  
Lignocellulosic Fibers ◽  
Potential Component

Zeolite was investigated as a potential component in the production of medium-density fiberboard (MDF). A mixture of beech (40%), oak (30%), and pine (30%) wood chips was used for fiber production. Chips were cooked for 4 min in an Asplund defibrator with a vapor pressure of 8 bar, and a temperature of 180 °C. Chemicals were added on fibers in the blow line. The resins were added at 11 wt% based on oven-dried wood fibers. Ammonium sulphate was added at 0.72 wt% based on resins. Paraffin wax was added as 1.8 wt% based on resin. Zeolite was prepared in a separate tank for its use instead of lignocellulosic fibers in the production of 1 m³ MDF. The fibers were dried to 12% moisture. A temperature of approximately 190 °C and a pressure of approximately 32 kg.m-² were applied to the mixture for 280 s to make MDF panels (500 x 490 x 14 mm). Mechanical properties of MDF boards were significantly increased for bending (MOE) and elastic modulus (MOR), but a little negatively affected on internal bond (IB), physical properties were negatively increased thickness swelling (ThS) and water absorption (WA). Consequently, increasing zeolite minerals in MDF boards showed best results of formaldehyde emission properties of MDF.

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