scholarly journals Adhesivity of Bio-Based Anhydrous Citric Acid, Tannin-Citric Acid and Ricinoleic Acid in the Properties of Formaldehyde-Free Medium Density Particleboard (MDP)

2020 ◽  
Vol 71 (3) ◽  
pp. 235-242
Author(s):  
Divino Eterno Teixeira ◽  
Danielle do Carmo Pereira ◽  
Ana Paula Diniz Nakamura ◽  
Sarah Silva Brum

Particles of flooded gum (Eucalyptus grandis) were bonded using three bio-based adhesives - anhydrous citric acid (CA), tannin-citric acid (TCA) and ricinoleic acid (RA) - from renewable sources and hot pressed to produce medium density particleboard (MDP). The bonding capacity of such adhesives and properties of the MDP were evaluated and compared to the requirements of seven grades of particleboards, according to the EN 312 (2010) standard. The RA did not create adhesion reaction with the wood particles. Adhesives formulated with CA and TCA presented capacity to bond eucalyptus particles into MDP confirmed by esterification reactions of the FTIRS analysis. MDP bonded with CA met requirements as high as grade P5 of the EN 312 (2010) standard for static modulus of elasticity (MOE) and internal bond (IB) and P2 for modulus of rupture (MOR). Panels bonded with TCA met requirements up to grade P3 for MOE, however, did not withstand water absorption.

2020 ◽  
Vol 70 (3) ◽  
pp. 370-377
Author(s):  
Cristian Grecca Turkot ◽  
Roy Daniel Seale ◽  
Edward D. Entsminger ◽  
Frederico José Nistal França ◽  
Rubin Shmulsky

Abstract The objective of this article is to evaluate the relationship between the dynamic modulus of elasticity (MOEd), which was obtained with acoustic-based nondestructive testing (NDT) methods, and static bending properties of two domestic hardwood oak species. The mechanical properties were conducted using static modulus of elasticity (MOE) and modulus of rupture (MOR) in radial and tangential directions. Mechanical tests were performed according to ASTM D143 on small clear, defect-free specimens from the two tree species: red oak (Quercus rubra) and white oak (Quercus alba). The MOEd was determined by two NDT methods and three longitudinal vibration methods based on the fast Fourier transform. The destructive strength values obtained in this study were within the expected range for these species. The MOE was best predicted by NDT methods for both species but also had a strong capability to predict MOR.


2021 ◽  
Vol 71 (4) ◽  
pp. 391-400
Author(s):  
Kayode Olaoye ◽  
Lawrence Aguda ◽  
Bolade Ogunleye

Abstract Acoustic test methods such as longitudinal vibration have been developed to predict the elastic properties of wood. However, attention has not been shifted to using this method to predict other mechanical properties, especially on Nigeria's preferred, and lesser-used wood species. Thus, we further investigate relationships among mechanical and acoustic properties of selected hardwood species with a view of predicting the mechanical properties of wood from acoustic parameters. Clear wood samples (324) of 20 by 20 by 20 mm3 were collected axially from Albizia adianthifolia, Gmelina arborea, Delonix regia, and Boscia anguistifolia trees, and conditioned before testing. The longitudinal vibration method was adopted to test for the dynamic (acoustic) parameters and properties (fundamental frequency, damping factor, dynamic modulus of elasticity, sound velocity, specific elastic modulus, radiation coefficient, acoustic conversion efficiency, acoustic impedance) while the universal testing machine was used to test for the mechanical properties (static modulus of elasticity, modulus of rupture, maximum compression strength parallel to grain). The damping factor, dynamic modulus of elasticity, and acoustic impedance were the best acoustic parameters that significantly correlated with the static modulus of elasticity (−0.57, 0.81, 0.76), modulus of rupture −0.64, 0.82, 0.85) and maximum compression strength parallel to grain (−0.52, 0.78, 0.84), respectively. There was a significant difference in the mechanical properties with respect to species, thus A. adianthifolia and G. arborea were mechanically better than D. regia and B. anguistifolia for construction or structural purposes. This study revealed that additional new acoustic measures are suitable for inferring mechanical wood properties.


FLORESTA ◽  
2014 ◽  
Vol 44 (4) ◽  
pp. 715
Author(s):  
Rafael Da Rosa Azambuja ◽  
Daniela Silva Lilge ◽  
Elio José Santini ◽  
Clovis Roberto Haselein

AbstractPERFORMANCE OF TWO TYPES OF CEMENT IN PRODUCTION OF CEMENT BONDED WOOD PANELS COMBINED WITH RICE HULLThe objective of this study was to evaluate the performance of two types of cement in the manufacturing of cement bonded wood panels with addition of rice hull. Sealers used were cement V-ARI (CP V) and cement Portland IV, pozzolanic (CP IV). Proportions adopted in the composition of panels were 0, 50 and 100 % rice hulls combined with 100, 50 and 0% of wood particles. Species used in this study were Eucalyptus grandis and Pinus elliottii. Parameters considered to evaluate panels were the mechanical properties. CP IV did not cure with the addition of pine particles in any proportion. The values of modulus of rupture (MOR) were higher with CP IV, but with the addition of rice hulls they decreased. CP V shoved higher internal bond strength in all proportions studied. Addition of rice hulls decreased all the mechanical properties studied in this work, therefore its use in cement bonded wood panels must be controlled, larger quantities than 50% of total vegetal mass weight are not recommended. Using Bison process as a reference, CP IV presented the necessary requirements to be used in cement bonded wood panels.Keywords: Eucalyptus grandis; CP IV; CP V-ARI; agricultural waste. ResumoDesempenho de dois tipos de cimentos na produção de painéis cimento madeira combinados com casca de arroz. O objetivo deste trabalho foi avaliar o desempenho de dois tipos de cimento na manufatura de painéis cimento madeira com adição de casca de arroz. Os cimentos avaliados foram o cimento Portland V - ARI (CP V) e o cimento Portland IV, pozolânico (CP IV). As proporções usadas na composição dos painéis foram de 0, 50 e 100% de casca de arroz combinadas com 100, 50 e 0% de partículas de madeira, sendo as espécies utilizadas Eucalyptus grandis e Pinus elliottii. Os parâmetros utilizados para avaliar os painéis foram as propriedades mecânicas. O CP IV não foi capaz de curar com a adição das partículas de pinus em nenhuma proporção. Os valores de módulo de ruptura (MOR) foram maiores com o CP IV, porém com adição de casca de arroz estes foram decrescendo. O CP V apresentou maiores valores de ligação interna para todas as proporções estudadas. A adição da casca de arroz diminuiu todas as propriedades estudadas neste trabalho portanto a sua utilização em painéis cimento madeira deve ser controladas e não aconselhadas em quantidades maiores que 50% do peso da massa vegetal utilizada. Usando o processo Bison como referência, o CP IV apresentou os requerimentos necessários para uso como painéis cimento madeira.Palavras-chave: Eucalyptus grandis; CP IV; CP V-ARI; resíduo agrícola.


Author(s):  
I. A. Shibaev ◽  
V. A. Vinnikov ◽  
G. D. Stepanov

Geological engineering often uses geomechanical modeling aimed to enhance efficiency of mining or performance of structures. One of the input parameters for such models are the static elastic moduli of rocks. This article presents the studies into the physical and mechanical properties of rocks-limestone of non-metamorphic diagenesis. The precision measurements of Pand S-waves are carried out to an accuracy of 0.2% by laser ultrasonics. The static moduli of elasticity and the deformation characteristics of rocks are determined in the uniaxial compression tests by the standards of GOST 21153.2-84 and GOST 28985-91, respectively. The correlation dependence is found between the static and dynamic elasticity moduli in limestone samples. The found correlation allows drawing the conclusion that the static modulus of elasticity can be estimated in non-destructive tests, which largely simplifies preliminary diagnostics of samples in case of limited number of test core.


2014 ◽  
Vol 1025-1026 ◽  
pp. 543-546
Author(s):  
Juliana Cortez Barbosa ◽  
Anderson Luiz da Silva Michelon ◽  
Elen Aparecida Martines Morales ◽  
Cristiane Inácio de Campos ◽  
André Luis Christoforo ◽  
...  

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gaurav Sancheti ◽  
Vikram Singh Kashyap ◽  
Jitendra Singh Yadav

Purpose The purpose of this study is to perform comprehensive investigation to assess the mechanical properties of nano-modified ternary cement concrete blend. Nano silica (NS) (1%, 2% and 3%) and waste marble dust powder (MD) (5%, 10% and 15%) was incorporated as a fractional substitution of cement in the concrete matrix. Design/methodology/approach In this experimental study, 10 cementitious blends were prepared and tested for compressive strength, flexural strength, splitting tensile strength and static modulus of elasticity. The microstructural characteristics of these blends were also explored using a scanning electron microscope along with energy dispersive spectroscopy and X-ray reflection. Findings The results indicate an enhancement in mechanical properties and refinement in pore structure due to improved pozzolanic activities of NS and the filling effect of MD. Originality/value To the best of the authors’ knowledge, no study has reported the mechanical and microstructural behavior of concrete containing marble and NS.


2018 ◽  
Vol 42 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Evelyn Hoffmamm Martins ◽  
Alan Pereira Vilela ◽  
Rafael Farinassi Mendes ◽  
Lourival Marin Mendes ◽  
Lívia Elisabeth Vasconcellos de Siqueira Brandão Vaz ◽  
...  

ABSTRACT Brazil is the second largest soybean producer in the world, with a yield of around 96.2 million tons per crop. This high yield leads to a great amount of waste resulting from soybean cultivation, which can reach approximately 41 million tons of waste per year. This material has lignocellulosic properties, which may enable its use as a raw material for particleboard production. Therefore, the objective of this study was to evaluate the use of soybean pods in particleboard production. For particleboard manufacture, wood of the hybrid Eucalyptus urophylla and Eucalyptus grandis was used, added with soybean pods, at proportions of 0%, 25%, 50%, 75% and 100%. For particleboard evaluation, a completely randomized design was used, with five treatments and three replicates, using linear regression and the Scott-Knott test at 5% significance for comparison among the different treatments. The properties apparent density, compaction ratio, water absorption after 2 and 24 hours, thickness swelling after 2 and 24 hours in water immersion, internal bonding, modulus of rupture and modulus of elasticity in bending properties were evaluated. The ratio soybean pod waste and eucalyptus particles in the panels led to an increase in water absorption values and thickness swelling, in addition to a decrease in mechanical properties. The production of panels with approximately 23% soybean pods is feasible.


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