Impact of log position in the tree on mechanical and physical properties of black spruce medium-density fibreboard panels

2007 ◽  
Vol 37 (5) ◽  
pp. 866-873 ◽  
Author(s):  
Jun Li Shi ◽  
Bernard Riedl ◽  
James Deng ◽  
Alain Cloutier ◽  
S. Y. Zhang
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Black Spruce ◽  
Analysis Of Covariance ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Medium Density Fibreboard ◽  
Significant Difference ◽  
Mechanical And Physical Properties ◽  
The Impact

Mechanical and physical properties of medium-density fibreboard (MDF) panels made from black spruce ( Picea mariana (Mill.) BSP) top, middle, and butt logs were studied. The analysis of variance and analysis of covariance were both performed to examine the impact of log position in the tree on panel modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), linear expansion (LE), thickness swell (TS), and water absorption. Results indicate that MOE and IB strength of MDF panels made from top and middle logs were significantly superior to those of panels made from butt logs; however, there was no significant difference in MOE and IB between panels made from top and middle logs. Water absorptions of top and middle log panels were significantly lower than that of panels made from butt logs, and the difference in water absorption between panels made from top and middle logs was not significant. TS of top log panels was the smallest among the panels from the three log positions in the tree and was significantly different from those of middle and butt log panels. TS of butt log panels was the highest, which was significantly different from that of top and middle log panels. The differences in LE among the panels made from top, middle, and butt logs were not significant. The comparison of MOR of top, middle, and butt log panels was dependent on panel density because of the interactions among the three groups. Top and middle log panels showed superior properties, because the thinner cell walls of fibres from top and middle logs resulted in an increased compaction ratio compared with the butt log panels. Panel density affected both panel MOR and MOE considerably; however, its impact on IB, LE, TS, and water absorption was not significant in this study. The equations describing the linear relationships between MOR, MOE, and panel density were developed.

Effect of juvenile wood on strength properties and dimensional stability of black spruce medium-density fiberboard panels

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Jun Li Shi ◽  
Shu Yin Zhang ◽  
Bernard Riedl
Keyword(s):  
Water Absorption ◽  
Dimensional Stability ◽  
Juvenile Wood ◽  
Black Spruce ◽  
Medium Density Fiberboard ◽  
Strength Properties ◽  
Analysis Of Covariance ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Mean Values

Abstract Strength properties and dimensional stability of medium-density fiberboard (MDF) panels made from black spruce (Picea mariana [Mill.] BSP.) 0–20, 21–40, and over 40 year old fiber were studied. An analysis of covariance (ANCOVA) was performed to examine the differences in modulus of rupture (MOR), modulus of elasticity (MOE), and thickness swell (TS) of the three types of panels, while panel density was treated as a covariate in order to adjust the mean values that were partly attributed to panel density. The results indicate that MOR, internal bond (IB), and water absorption of MDF panels made from 0–20 year old fiber, which contained 100% juvenile wood, were significantly superior to those of panels made from 21–40 and over 40 year old fiber; but linear expansion (LE) of MDF panels made from 0–20 year old fiber was significantly larger than that of panels from the other two age classes. The differences in MOR, IB, water absorption, and LE between panels made from 21–40 and over 40 year old fiber were not significant. The comparisons of panel MOE and TS were relatively dependent on panel density due to existence of interactions among the three age groups.

Effect of Ozone Treatment on Properties of Screw Pressed and Non-Screw Pressed Empty Fruit Bunch Medium Density Particleboard

2015 ◽  
Vol 1134 ◽  
pp. 116-122
Author(s):  
Roslan Ali ◽  
Mohamad Nurul Azman Mohammad Taib ◽  
Kamal Wok ◽  
Shawaluddin Tahiruddin ◽  
Mohd Amrin Abdullah
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Water Absorption ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Ozone Treatment ◽  
Medium Density ◽  
Internal Bonding ◽  
Empty Fruit Bunch ◽  
Thickness Swelling

This study was done to investigate the effects of ozone treatment as a method to improve the properties of empty fruit bunch (EFB) medium density particleboard. Two types of EFB were used in this study i.e. screw pressed and non-screw pressed empty fruit bunch. These EFB were treated in an ozone chamber for 8 hours prior to particleboard manufacturing. The mechanical properties, Modulus of Elasticity (MOE), Modulus of Rupture (MOR) and Internal Bonding (IB) and physical properties, water Absorption (WA) and Thickness Swelling (TS) of EFB particleboard were determined. The results showed that the ozone treatment could increase the MOR and IB values of EFB particleboard, but had no significant effect on MOE values. For physical properties, the values showed no improvement for TS and WA. The panels manufactured using ozone treatment was found suitable for applications for furniture products.

scholarly journals Influence of varying density on the mechanical and physical properties of Medium Density Fibreboard (MDF) containing kenaf

2020 ◽  
Vol 713 ◽  
pp. 012020
Author(s):  
Noorli Ismail ◽  
Muhammad Azzim Mohmed Jomali ◽  
Hasniza Abu Bakar ◽  
Tong Yean Ghing ◽  
Nik Mohd Zaini Nik Soh ◽  
...  
Keyword(s):  
Physical Properties ◽  
Medium Density ◽  
Medium Density Fibreboard ◽  
Mechanical And Physical Properties

scholarly journals Evaluation of Functional Features of Lignocellulosic Particle Composites Containing Biopolymer Binders

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7718
Author(s):  
Aneta Gumowska ◽  
Eduardo Robles ◽  
Grzegorz Kowaluk
Keyword(s):  
Physical Properties ◽  
Considerable Change ◽  
Binder Content ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Scanning Calorimetry ◽  
Mechanical And Physical Properties ◽  
Functional Features ◽  
The Impact ◽  
Internal Bonding Strength

In this research, the assessment of the impact of natural biopolymer binders on selected mechanical and physical properties of lignocellulosic composites manufactured with different resination (12%, 15%, 20%). Different mechanical and physical properties were determined: modulus of rupture, modulus of elasticity, internal bonding strength, thickness swelling, water absorption, contact angle, and density profile. Moreover, thermal properties such as thermogravimetric analysis and differential scanning calorimetry were studied for the polymers. The results showed significant improvement of characterized features of the composites produced using biopolymers. However, the rise of the properties was visible when the binder content raised from 12% to 15%. Further increase of biopolymer binder did not imply a considerable change. The most promising biopolymer within the tested ones seems to be polycaprolactone (PCL).

scholarly journals Investigation of the use of old railroad ties (Fagus orientalis) and citrus branches (orange tree) in the particleboard industry

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6984-6992
Author(s):  
Ali Hassanpoor Tichi
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Modulus Of Elasticity ◽  
Internal Bond ◽  
Modulus Of Rupture ◽  
Aspen Wood ◽  
Fire Retardancy ◽  
Thickness Swelling ◽  
Mechanical And Physical Properties ◽  
Four Levels

Effects of two widely available and underutilized lignocellulosic materials on the mechanical and physical properties of particleboards were investigated in this work. The ratio of mixtures lignocellulosic flakes at four levels (100% aspen wood), (50% aspen wood: 25% citrus: 25% old railroad ties), (50% aspen wood: 50% citrus), and (50% aspen wood: 50% old railroad ties), and the percentage of resin in two levels (8 and 12%) were considered as variable factors. The 100% aspen wood (Populus tremula) was mixed as a control board (100% aspen wood). Then the mechanical and physical properties of the samples including modulus of rupture, modulus of elasticity, internal bond, water absorption, and thickness swelling after 2 h and 24 h of immersion (EN 310-319) and fire resistance (ISO 11925-2) were measured. The results showed that with increasing poplar wood in mixtures, modulus of rupture, modulus of elasticity, internal bond increased, while water absorption and thickness swelling decreased. Also, in comparison with the control boards, the boards that were made by mixing 50% poplar and 50% citrus branches with 12% glue had the highest mechanical strength. The results also showed that increasing the amount of old railroad ties chips in mixing caused a significant decrease in the fire retardancy of the boards.

Medium density boards made of groundwood fibres: an analysis of their mechanical and physical properties

2018 ◽  
Vol 77 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Sauro Bianchi ◽  
Heiko Thömen ◽  
Stefan Junginger ◽  
Frédéric Pichelin
Keyword(s):  
Physical Properties ◽  
Medium Density ◽  
Mechanical And Physical Properties

scholarly journals The Impact of the reciprocal Teaching Strategy on the Development of Achievement in Islamic Education in Seventh Grade Students in Jordan

2019 ◽  
Vol 3 (17) ◽  
Author(s):  
Somaya Mohammed Al- Bardini
Keyword(s):  
Experimental Approach ◽  
Teaching Strategy ◽  
Islamic Education ◽  
Analysis Of Covariance ◽  
Reciprocal Teaching ◽  
Seventh Grade ◽  
Significant Difference ◽  
Quasi Experimental ◽  
The Impact ◽  
Experimental Group

The purpose of this study was inquiring The Impact of the reciprocal Teaching Strategy on the Development of Achievement in Islamic Education in Seventh Grade Students in Jordan. To achieve goals of this study, a test has been developed to observe the Development of Achievement. The researcher adopted a quasi- experimental approach in which the experimental group consisting of (30) students was taught in accordance with reciprocal Teaching Strategy. At the same time, the controlled group consisting of (30 students) was taught in the traditional way. The tests and the motive measuring was applied prior and post- teaching on both groups. The Analysis of Covariance results (Test- t) indicated a significant difference at (α≤0.05) between the two groups, which is attributed to the reciprocal Teaching Strategy, in developing the Acquiring Concepts in Islamic , of Learning Islamic Education Course for the experimental group. The results also indicated variation in the performance of (the experimental group) students in the posttest of the reciprocal Teaching Strategy (in developing the Academic achievement The study recommended introducing the reciprocal Teaching Strategy in the teaching of Islamic Education Course, and conducting other similar studies in different educational stages.

Bark particleboard: pressing time, particle geometry and melamine overlay

2008 ◽  
Vol 84 (2) ◽  
pp. 244-250 ◽  
Author(s):  
Pierre Blanchet ◽  
Alain Cloutier ◽  
Bernard Riedl
Keyword(s):  
Physical Properties ◽  
Linear Expansion ◽  
Black Spruce ◽  
Value Added ◽  
Wood Products ◽  
Curing Time ◽  
Mechanical And Physical Properties ◽  
Wood Fibres ◽  
Wood Particles ◽  
Particle Geometry

Previous research has shown the possibility of making particleboards from bark residues. The objective of this study is to demonstrate the possibility of making black spruce (Picea mariana) bark particleboards with a short curing time in the pressing schedule, and to assess the effect of bark particle geometry on the mechanical and physical properties of bark particleboards. Additionally, melamine films were applied on bark composite boards and assessed. Mechanical and physical properties such as internal bond, modulus of elasticity, modulus of rupture, linear expansion and thickness swell were evaluated from five to two minutes curing time with a one-minute step. Mechanical and physical properties were also evaluated for four particle combinations. Different particles were used to qualify the effect of particle geometry. Combinations were made from two types of bark particles and two types of wood particles. These particles are hammermilled bark particles, refined bark, wood particles, and wood fibres (MDF). Melamine overlay was applied on the particleboard made with these four particle combinations to evaluate the behaviour of the film with the presence of bark in the composite. Good mechanical properties were obtained with a four-minute curing time. The use of wood fibres such as fibres from the MDF industry instead of wood particles, as in the particleboard industry, helped to reduce the linear expansion results. None of the particleboards produced in this study were able to meet ANSI standard requirements for linear expansion. The pressing of white melamine overlay results in a different colour according to the colorimeter results when it is applied on a bark particleboard compared to conventional particleboards. No differences were observed when a black film was applied. Key words: black spruce bark, bark particleboards, bark particle geometry, particleboard laminations, value-added wood products

Effect of Firing Temperature on Mechanical and Physical Properties of Porcelain Balls as Grinding Media

2017 ◽  
Vol 888 ◽  
pp. 37-41
Author(s):  
Hasrul Yahya ◽  
Mohd Roslee Othman ◽  
Zainal Arifin Ahmad
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Water Absorption ◽  
Firing Temperature ◽  
Chemical Resistance ◽  
Firing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grinding Media ◽  
Mechanical And Physical Properties

Porcelain balls as grinding media are produced by firing process of clay, quartz and feldspar mixtures. This application need high technological properties such as high compressive strength and hardness, wear resistance, low water absorption and excellent chemical resistance. These properties are associated with higher firing temperatures. The porcelain balls were prepared by mixing 30 wt.% clay, 40 wt.% feldspar and 30 wt.% quartz. The samples were sintered at 1200°C, 1230°C, 1250°C, 1270°C and 1300°C for 2 hours with heating rate of 3°C/min. Both green powder and fired samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM).The properties of the fired samples were evaluated by compressive strength, hardness, shrinkage, water absorption, bulk density, and porosity measurement. Increasing of compressive strength, hardness and density are associated with increasing of firing temperatures. Porcelain balls PB1 and PB2 can be produced as grinding media with optimum mechanical and physical properties at firing temperature 1270°C and 1250°C, respectively.

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