scholarly journals Effect of Variable Conditions of Exposure on the Physical and Mechanical Properties of Blockboards

2022 ◽  
Vol 12 (2) ◽  
pp. 609
Author(s):  
Octavia Zeleniuc ◽  
Camelia Coșereanu

The growing demand for wood and the continued increase of the raw material price have resulted in companies using more efficient wood resources in wood-based products such as blockboard. These boards are used in the field of interior design, especially. The aim of this research was to evaluate the effect of variable environmental conditions on the physical and mechanical properties of blockboard (BK). Two types of commercial BK were exposed in variable environmental conditions (kitchen, bathroom and climatic chamber) for three months. The BK structures were composed of veneer (V) and high-density fibreboards (HDF) for the face sheets and glued, solid wood, resinous strips for the core. The temperature and relative humidity of the air (RH) ranged from 18 °C to 25 °C and from 25% to 90%, respectively. In the climatic chamber (CC), the dynamics of the parameter variations were different than in the other two exposure climates, being determined by the programmed cyclic changes in RH. The changes observed on physical and mechanical properties were more extreme for the blockboards tested in the CC than in the kitchen (K) and bathroom (Ba). After 3 months of exposure in the CC, the thickness and weight of the boards increased by 1.8 and 1.1 times, respectively, for veneered BK, and by 4.4 and 0.4 times, for BK with HDF faces, compared to values recorded in the kitchen. The panels exposed in the CC exhibited the highest increase in moisture content (MC): 41% for veneered BK and 82% for BK with HDF faces after three months of exposure, followed by those exposed in the bathroom and kitchen. Increases in MC determined decreases of flexural properties and soundness surfaces, more evident for HDF face structures compared to V ones.

2011 ◽  
Vol 471-472 ◽  
pp. 31-36 ◽  
Author(s):  
Taghi Tabarsa

In this study feasibility of using of mixture of bagasse and industrial wood particles for producing single and three layer particleboard . The aim of this study was to consider bagasse as partially substitute particleboard industry raw material. Variables were type of board at two levels (single and three layer), percentage of added bagasse to industrial particles at 4 levels (20%,30%, 40% and 50%) , and press temp. at two levels (165OC and 180 OC ). In producing three layer particleboard wood and bagasse particles were separated and placed in different layers so that bagasse particles were located in the face layers and wood particles were placed in the core of board. But in one layer particleboard bagasse and wood particles were used in the form of mixture. Effect of variables on physical and mechanical properties of particleboard were determined. Results showed that in three layer particleboard physical and mechanical properties were better than single layer particleboard. Increasing press temperature caused improvement in particleboard properties in most cases due to intermeshing and increasing softening wood and bagasse particles. The optimum treatment in this study was found to be adding 50% bagasse and press temperature of 180 OC.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1750 ◽  
Author(s):  
Radosław Mirski ◽  
Pavlo Bekhta ◽  
Dorota Dziurka

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).


2014 ◽  
Vol 92 ◽  
pp. 188-193 ◽  
Author(s):  
Tuna Aydin ◽  
Alpagut Kara

Spodumene, which is a lithium alumina silicate, has been used as a raw material in the production of thermal shock resistant whitewares and sanitarywares. The presence of spodumene results in enhancement of mullitization and imparts better physical and mechanical properties to ceramics. In this study, the influence of Lithium alumina silicate phases on the mechanical properties of standard porcelain stoneware body was investigated. Especially solid-solid reactions were observed between spodumene and quartz or spodumene and clay. These solid-solid reactions bring about a newly formed lithium alumina silicate (LAS) phases. Spodumene allows the development of a low viscosity liquid phase and results in a decrease in closed porosity, also with increase in bulk density, bending strength and elastic modulus.


Teknomekanik ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 14-19
Author(s):  
M Saddikin ◽  
Hendri Nurdin ◽  
Primawati Primawati

The raw materials of the timber industry, especially furniture, are increasingly difficult to obtain in the quantity and quality needed. The development efforts carried out were utilizing Nipah coir waste as a raw material for making particle boards. Particle boards are panel boards made of wood particles or materials containing lignocellulose. Nipah plants contain 27.3% lignin and 36.5% cellulose which has the potential to be used as raw material for particleboard production. This study aims to reveal the physical and mechanical properties of particleboards made from Nipah fruit fibre with adhesive using tapioca flour. The making of particle board is done with a ratio of 90%: 10%, 80%: 20%, 70%: 30%, 60%: 40%, by giving a pressure of 100 kg / cm2. Particle testing is carried out according to the JIS A 5908 standard (2003). From this study, the optimum results were obtained in variations of 60%:40%. The particle physical properties which have an average density value of 1.15 gr / cm3 and an average moisture content of 5.8%. While the mechanical properties obtained by the value of Modulus of Elasticity an average of 21,188.93 kg / cm2. This shows the particle board variations of 60%: 40% produced to meet the JIS A 5908 (2003) standard. Based on the analysis of the quality variations 60%: 40% of particle boards can be recommended as raw materials for interior furniture.


2021 ◽  
Vol 891 (1) ◽  
pp. 012007
Author(s):  
Y S Hadi ◽  
E N Herliyana ◽  
I M Sulastiningsih ◽  
E Basri ◽  
R Pari ◽  
...  

Abstract Jabon (Anthocephalus cadamba) laminas were impregnated with polystyrene and reached 21.2% polymer loading. The laminas were manufactured for three-layer glued laminated timber (glulam) using isocyanate glue with glue spread 280 g/m2 and cold-press process. For comparison purposes, untreated glulam as control and also solid wood were prepared. The physical-mechanical properties were evaluated according to the Japanese Agricultural Standard (JAS) 234-2003. The results showed that the color of glulam was not different from polystyrene glulam. The density of polystyrene glulam was higher than untreated glulam and solid wood, but the moisture content was lower than the other. The product kinds of solid wood, untreated glulam, and polystyrene glulam did not affect shear strength and modulus of rupture (MOR), while the modulus of elasticity (MOE) of untreated glulam and hardness of polystyrene glulam were the highest values and the other products were not different one each other. Both kinds of glulam fulfilled the Japanese standard in terms of moisture content, MOR, and delamination in hot water, but MOE and shear strength did not. Regarding its advantages, polystyrene glulam could be further developed using a higher wood density.


2021 ◽  
Vol 42 (1) ◽  
pp. 21
Author(s):  
Vasni Oliveira da Silva Junior ◽  
Victor Mateus Pavão ◽  
André Camacho Pontremolez ◽  
Bruno de Medeiros Costa ◽  
Gerson Cendes Saragosa ◽  
...  

This work presents part of a study whose main objective is to observe the behavior of the physical and mechanical properties of the materials (raw material) and of products made for the civil construction from the precast concrete industry, such as concrete blocks and pavers for interlocking floors. Through the investigation, was identified the potential of using the concrete blocks waste of the production as aggregates added to the concretes utilized to produce pavers. Thus, it is expected that this work contributes as a basis for obtaining scientific and technical knowledge regarding the materials and procedures that must be adopted for the manufacture of pavers, allowing their production for commercialization.


2005 ◽  
Vol 59 (7-8) ◽  
pp. 175-179
Author(s):  
Bojana Klasnja ◽  
Sasa Orlovic ◽  
Nenad Radosavljevic ◽  
Miroslav Markovic

The properties of willow wood (structural-physical and mechanical properties and chemical composition) were investigated to determine the parameters of the technological process of semichemical and sulphate pulp manufacture. The experimental material was willow wood Salix alba cl. 107/65/7. Semichemical and sulphate pulp were obtained in the laboratory. The yield, chemical properties and physical-mechanical properties of the obtained intermediate products intended for paper manufacture, were determined. The properties of poplar wood Populus deltoides Bartr. cl.725, were studied and its pulp production performed with the aim of comparison.


2020 ◽  
Vol 787 (12) ◽  
pp. 66-71
Author(s):  
H.N. Mammadov ◽  
◽  
I.H. Suleymanova ◽  
B.M. Tahirov ◽  
◽  
...  

The properties of high-strength artificial porous aggregate from glass-containing waste of metallurgical productions are described. The developed technology makes it possible to expand the raw material base for the production of aggregates for light concrete. Granulated slags of metallurgical productions – the main (M0>1) slags of the Novokuznetsk Iron and Steel Plant and acid (M0<1) slags of the Gorky plant are studied. According to the results of studies, it was found that the optimal swelling interval for acidic slags is 1000–1100оC, and for basic slags-1100–1150оC. A high – strength artificial porous aggregate-slag gravel with a bulk density of 340–780 kg/m3 and a compressive strength in the cylinder of 2.8–12.3 MPa was obtained. The main physical and mechanical properties of the resulting aggregate, which meets the requirements of the current standard GOST 9757–90 “Gravel, crushed stone and sand. Artificial porous”, were studied. The aggregate obtained is almost twice as strong as the known aggregate of expanded clay gravel. With the use of porous gravel and sand, light concrete of strength class B7,5–B40 and a density of 1100–1600 kg/m3 was obtained.


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