scholarly journals Effect of Soaking/Oven- Drying on Mechanical and Physical Properties of Birch (Betula spp.) Plywood

2021 ◽  
Vol 72 (2) ◽  
pp. 121-129
Author(s):  
Regino Kask ◽  
Harri Lille ◽  
Mihkel Kiviste ◽  
Silver Kruus ◽  
Johann Olaf Lääne
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Oven Drying ◽  
Mechanical And Physical Properties ◽  
The Face ◽  
European Standards ◽  
Fractional Equation

The objective of this study was to explore some of the physical and mechanical properties of 9-layer birch (Betula spp.) plywood with the addition of phenol-formaldehyde glue, in cases in which the cutting edges of the samples are coated with the damp-proof mastic Fibergum, and in case in which they remain unprocessed (uncoated), following a total of ten cycles of soaking/oven-drying. The properties to be determined were the bending strength (BS), modulus of elasticity in bending (MOE), thickness swelling (TS) and restore dimensions (RD), which were tested according to the European standards (EN). A linear-fractional equation and linear relationship were used for the approximation of any change in the physical and mechanical properties of the samples depending upon the number of soaking/oven-drying cycles. It was shown that the values of the properties investigated were most affected by the first soaking and drying cycle. Thereafter, BS and MOE levels decreased smoothly at a low rate, but the values of TS became stabilised. The BS and MOE values for the wet samples with coated cutting edges were higher than when they were uncoated, as the moisture levels in the former case were lower. After the first soaking of the samples with coated cutting edges, the retention values were as follows: BS at 52.8 % and 66.7 % for the major and minor axes, respectively, with the same applying to MOE at 61.9 % and 64.2 %, while TS was at 105.2 %. To clarify the phenomenon that causes a decrease of the properties, the face plies and edge structures of the initial dry samples and of the samples after the first, second and ninth soaking/oven-drying cycles were studied using the X-Ray technique.Ključne riječi

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

scholarly journals Relationships between Thermoplastic Type and Properties of Polymer-Triticale Boards

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1750 ◽  
Author(s):  
Radosław Mirski ◽  
Pavlo Bekhta ◽  
Dorota Dziurka
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Hydrophobic Properties ◽  
Pine Wood ◽  
Moisture Contents ◽  
The Face

This study examined the effects of selected types of thermoplastics on the physical and mechanical properties of polymer-triticale boards. The investigated thermoplastics differed in their type (polypropylene (PP), polyethylene (PE), polystyrene (PS)), form (granulate, agglomerate) and origin (native, recycled). The resulting five-ply boards contained layers made from different materials (straw or pine wood) and featured different moisture contents (2%, 25%, and 7% for the face, middle, and core layers, respectively). Thermoplastics were added only to two external layers, where they substituted 30% of straw particles. This study demonstrated that, irrespective of their type, thermoplastics added to the face layers most favorably reduced the hydrophobic properties of the boards, i.e., thickness, swelling, and V100, by nearly 20%. The bending strength and modulus of elasticity were about 10% lower in the experimental boards than in the reference ones, but still within the limits set out in standard for P7 boards (20 N/mm2 according to EN 312).

An attempt to use „Tetra Pak” waste material in particleboard technology

2021 ◽  
Vol 114 ◽  
pp. 70-75
Author(s):  
Radosław Auriga ◽  
Piotr Borysiuk ◽  
Alicja Auriga
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Waste Material ◽  
Thickness Swelling ◽  
The Core ◽  
Tetra Pak ◽  
The Impact

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.

scholarly journals INFLUENCE OF THERMAL MODIFICATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OF Eucalyptus badjensis MIXED PARTICLEBOARD / OSB PANELS

FLORESTA ◽  
2021 ◽  
Vol 51 (2) ◽  
pp. 419
Author(s):  
Giuliano Ferreira Pereira ◽  
Setsuo Iwakiri ◽  
Rosilani Trianoski ◽  
Polliana D'angelo Rios ◽  
Renan Zunta Raia
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Dry Mass ◽  
Thermal Modification ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Swelling Properties ◽  
Different Temperatures

The objective of this research was to evaluate the effects of thermal modifications, at different temperatures and exposure times, on the technological properties of mixed particleboard / OSB panels made out of Eucalyptus badjensis. Using the wood of Eucalyptus badjensis, Particleboard, OSB and mixed Particleboard/OSB panels (control and thermally modified) were manufactured. The mixed panels’ thermal modification was carried out under three temperatures (180ºC, 200ºC and 220ºC) and two exposure times (10 minutes and 12 minutes). For the panels’ manufacturing, 6% of phenol-formaldehyde adhesive and 1% of paraffin were employed, which was calculated based on the particles’ dry mass. The water absorption and thickness swelling properties were evaluated after 2 and 24 hours of immersion, in addition to the panels’ modulus of elasticity, modulus of rupture and internal bond. Based on the results, we were able to conclude that the thermal modification affected most of the physical properties positively. From the different exposure times studied, the most effective one was the period of 12 minutes, especially for water absorption after 2 hours, which caused a reduction of 11.27%. In turn, the most effective temperature was of 220ºC, highlighting the thickness swelling after 24 hours, which caused a swelling decrease of 23.76% in comparison with the control panels. Regarding the mechanical properties, the thermal modification, in terms of the studied exposure times and temperatures, did not affect the results of the mixed particleboard /OSB panels. 

scholarly journals Utilization of Partially Liquefied Bark for Production of Particleboards

2020 ◽  
Vol 10 (15) ◽  
pp. 5253 ◽  
Author(s):  
Wen Jiang ◽  
Stergios Adamopoulos ◽  
Reza Hosseinpourpia ◽  
Jure Žigon ◽  
Marko Petrič ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Thickness Swelling ◽  
Mechanical And Physical Properties ◽  
Dry Conditions ◽  
Synthetic Adhesives ◽  
European Standards ◽  
Muf Adhesives

Bark as a sawmilling residue can be used for producing value-added chemicals and materials. This study investigated the use of partially liquefied bark (PLB) for producing particleboard with or without synthetic adhesives. Maritime pine (Pinus pinaster Ait.) bark was partially liquefied in the presence of ethylene glycol and sulfuric acid. Four types of particleboard panels were prepared with a PLB content of 4.7%, 9.1%, 20%, and 33.3%, respectively. Another five types of particleboard panels were manufactured by using similar amounts of PLB and 10 wt.% of melamine–urea–formaldehyde (MUF) adhesives. Characterization of bark and solid residues of PLB was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and automated vapor sorption (AVS). Mechanical and physical properties of the particleboard were tested according to the European standards EN 310 for determining modulus of elasticity and bending strength, EN 317 for determining thickness swelling after immersion in water, and EN 319 for determining internal bond strength. The results showed that the increase in PLB content improved the mechanical strength for the non-MUF boards, and the MUF-bonded boards with up to 20% of PLB met the requirements for interior uses in dry conditions according to EN 312. The non-MUF boards containing 33.3% of PLB and the MUF-bonded boards showed comparable thickness swelling and water absorption levels compared to the reference board.

Engineered Wood Composite of Laminated Veneer Lumber: Physical and Mechanical Properties

2016 ◽  
Vol 842 ◽  
pp. 103-128
Author(s):  
Kang Chiang Liew ◽  
Singan Grace
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
P Value ◽  
Thickness Swelling ◽  
Laminated Veneer Lumber ◽  
Physical Testing ◽  
Acacia Hybrid

Utilisation of forest plantation species such as Acacia hybrid has been used in wood-based industry as an alternative to solid wood that was usually attained from natural forest. While, the under-utilised species such as Mangifera sp. is not often been used as raw material for wood products, in this study, laminated veneer lumber (LVL) has been produced from Acacia hybrid and Mangifera sp. The physical and mechanical properties of LVL were determined and compared. For physical testing, the range value of moisture content was 9.41% to 14.56%, Density was 487.90 kg/m3 to 699.10 kg/m3, thickness swelling was between 0.20% to 6.05%, water absorption between 32.71% to 91.25%, and rate of delamination from 0% to 100%. Mangifera sp. LVL has higher moisture content, rate of delamination, and water absorbency. In mechanical testing, it is been found that Acacia hybrid LVL has overall higher strength compared to Mangifera sp. LVL, in terms of static bending strength (MOR and MOE), shear strength, and compression strength. Range of value for MOR was between 10.27 N/mm2 to 129.99 N/mm2, MOE between 1138 N/mm2 to 16472.93 N/mm2, shear strength between 0.43 N/mm2 to 3.40 N/mm2, and compression between 139.45 N/mm2 to 6749.74 N/mm2. For physical testing, the overall result of p-value for moisture content, water absorption, and delamination were significant at p ≤ 0.05, while density and thickness swelling were not significant at p ≥ 0.05. For overall result, the p-value for static bending strength (MOR and MOE) was significant at p ≤ 0.05 while for shear strength and compression strength were not significant at p ≥ 0.05.

Selected Physical and Mechanical Properties of 2-Ply Bamboo Laminated Lumber with Modified Phenol Formaldehyde

2015 ◽  
Vol 1088 ◽  
pp. 583-586
Author(s):  
Zhi Wei Huang ◽  
Ming Jie Guan
Keyword(s):  
Mechanical Properties ◽  
Surface Density ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Environmental Friendly ◽  
Density Surface ◽  
Bonding Surface ◽  
Better Than

In this paper, environmental friendly phenol formaldehyde modified with larch thanaka and urea was used to make 2-ply bamboo laminated lumber. Effects of two assemble patterns (inner to inner and outer to outer) on physical and mechanical properties of 2-ply bamboo laminated lumber from carbonized and bleached bamboo strips were investigated. The results showed that modulus of elasticity (MOE) and modulus of rupture (MOR) of carbonized bamboo laminated lumber were better than that of bleached bamboo laminate lumber. It illustrated that physical and mechanical properties of carbonized bamboo laminated lumber became better. The MOE and MOR of bamboo laminated lumber, bonding with inner (low density surface) to inner surface, were better than that of outer (high density surface) to outer surface. It meant that MOE and MOR of bamboo laminated lumber were increased by the bonding surface density decreased of bamboo unit. Thickness swelling of carbonized bamboo laminated lumber was lower than that of bleached bamboo, which meant its dimensional stability was better than that of bleached bamboo laminated lumber.

Reactive maleic anhydride polyolefins (MAPOs) in oriented strand board. Part 2: Influence on physical and mechanical properties

Holzforschung ◽  
2011 ◽  
Vol 65 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Sudip Chowdhury ◽  
Vikram Yadama
Keyword(s):  
Mechanical Properties ◽  
Maleic Anhydride ◽  
Oriented Strand Board ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Moisture Resistance ◽  
Thickness Swelling ◽  
Water Vapor Transmission ◽  
Reduced Water

Abstract The use of reactive polyolefin and phenol formaldehyde (PF) resin blends to improve the moisture durability of oriented strand composite (OSC) panels was investigated. Test panels were hot pressed with adhesive blends consisting of varying proportions of PF and maleic anhydride polypropylene (MAPP) anionic emulsion, and their physical and mechanical properties were evaluated. The addition of MAPP did not significantly affect the modulus of elasticity (MOE) of the panels, but reduced the modulus of rupture in bending (MOR) for 12% moisture content (MC) and 24-h soak specimens. An increase in PF content significantly improved the MOE and MOR of specimens subjected to the environment. Adding MAPP reduced internal bond strength, particularly at higher PF levels. The addition of MAPP and raising PF levels significantly reduced water absorption and thickness swelling of the panels. At higher MAPP levels, the water vapor transmission in OSC as well as the permeance of the material, was reduced. Composite board equilibrated to lower MC with increasing MAPP content in the resin blend. The results indicate that increasing the PF content is the most effective method of improving both moisture resistance and the mechanical properties of OSC; addition of MAPP improves the moisture resistance of the panels, but significantly reduces their mechanical properties.

Influence of Resin Content on Composite Materials Railway Sleepers for Physical and Mechanical Properties

2011 ◽  
Vol 217-218 ◽  
pp. 495-499
Author(s):  
Yue Sun ◽  
Sheng Ling Xiao
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Bending Strength ◽  
Processing System ◽  
Physical And Mechanical Properties ◽  
Resin Content ◽  
Thickness Swelling ◽  
Pressing Temperature ◽  
Pressing Time ◽  
Resol Resin

It studies the influence of resin content on composite materials railway sleepers for physical and mechanical properties,which is for the preparation of composite materials railway sleepers.It used resol resin setting hot pressure at 2.5Mpa, hot pressing temperature at 170°C, pressing time at 5-6min. The results showed that as the resin content increases, the static bending strength (MOR) first increased and then decreased, the internal bond strength (IB) rised, 2h thickness swelling (2h TS) decreased. Through the analysis of experimental data by using DPS data processing system, resin content had a significant impact on 2h TS.It also affected MOR, IB.But it had little effect on measured density (D), water content (W) and impact strength (IL).

scholarly journals Size Effect of Core Strands on the Major Physical and Mechanical Properties of Oriented Strand Boards from Fast Growing Tropical Species

2021 ◽  
Author(s):  
Wan Mohd Nazri Wan Abdul Rahman ◽  
Nur Sakinah Mohamed Tamat ◽  
Nor Yuziah Mohd Yunus ◽  
Jamaludin Kasim
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Major Axis ◽  
Resin Content ◽  
Tropical Species ◽  
Thickness Swelling ◽  
Bending Properties ◽  
Board Density ◽  
Fast Growing ◽  
The Face

Oriented strand board (OSB) is generally used for sheathing in residential walls, floors, and roofs. Because of its low pricing and utilisation of tiny diameter logs from fast-growing trees and thinning logs as raw materials, OSB is anticipated to gain popularity. In chapter, board properties of OSB using smaller strand size of Leucaena leucocephala as core layer had been studied. Small strand size of S3 (length = 75 mm, width = 3.2 to 6.3 mm) was located in the middle layer of the board while bigger strand sizes of S1 (length = 75 mm, width = 12.7 to 19.0 mm) and S2 (length = 75 mm, width = 6.3 to 12.7 mm) were located at the face and back layers. Utilization of smaller strands (S3) in the middle layers may yield boards that have better physical and mechanical properties. Except for MOR in the minor axis, board density and resin content were shown to have a substantial impact on physical and mechanical properties. Except for MOR in the major axis, strand size had little affected on physical and mechanical properties. The effects of board density on mechanical properties were discovered to affect significantly different. With a positive correlation, board density had a significant effect on thickness swelling. Between S1+S3 and S2+S3 strand size, there is no significant effect on bending properties, internal bond strength and thickness swelling. The effect of resin content on bending properties revealed a significant difference of MOR in major axis, as well as MOE values in both major and minor axes. Even when the resin content was as low as 5%, all treatments of OSB passed the general requirement of general purpose OSB.

Sign in / Sign up

Export Citation Format

Share Document