scholarly journals Mechanical Properties and Formaldehyde Release of Particleboard Made with Lignin-Based Adhesives

2021 ◽  
Vol 11 (18) ◽  
pp. 8720
Author(s):  
Gabriela Balea Paul ◽  
Maria Cristina Timar ◽  
Octavia Zeleniuc ◽  
Aurel Lunguleasa ◽  
Camelia Coșereanu
Keyword(s):  
Mechanical Properties ◽  
Structural Changes ◽  
Beech Wood ◽  
Single Layer ◽  
Formaldehyde Emission ◽  
Positive Influence ◽  
Carbonyl Groups ◽  
Formaldehyde Release ◽  
Spruce Wood ◽  
Wood Particles

The aim of this research was to evaluate the potential of magnesium lignosulfonate as adhesive in particleboard manufacturing. Diphenylmethane diisocyanate (PMDI) between 1% and 3% and glucose (1% of the lignosulfonate content) were added as potential cross-linkers in the adhesive formulations. Mixed beech and spruce wood, 30% beech wood and 70% spruce wood, were employed for the configuration of the panel structure. The density, mechanical properties and formaldehyde emission of single-layer particleboard were investigated. Spectroscopic analysis (FTIR) revealed structural changes brought by oxidation that may indicate depolymerization by the splitting of C-O-C bonds and formation of carbonyl groups. Mechanical properties were improved, and the highest average values were recorded for panels having as adhesives oxidized lignin with cross-linkers as follow: 15 N/mm2 (MOR), 3320 N/mm2 (MOE) and 0.48 N/mm2 (IB). The density profile presented higher values for faces in case of oxidized lignin panels. Changes were observed for oxidized lignin with cross-linker panels wherein the core had higher values. The results showed that the panels manufactured with adhesives composed of oxidized lignosulfonate (20% of the dried wood particles weight) and the addition of PMDI and glucose in various percentages have a positive influence on their formaldehyde release and mechanical properties requested by EN 312 (2004) standard.

Producing Particleboard Using of Mixture of Bagasse and Industrial Wood Particles

2011 ◽  
Vol 471-472 ◽  
pp. 31-36 ◽  
Author(s):  
Taghi Tabarsa
Keyword(s):  
Mechanical Properties ◽  
Single Layer ◽  
Physical And Mechanical Properties ◽  
Raw Material ◽  
Press Temperature ◽  
The Core ◽  
Wood Particles ◽  
The Face ◽  
Particleboard Properties ◽  
Better Than

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.

Effect of paraffin application technique on the physical and mechanical properties of particleboard

2014 ◽  
Vol 21 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Mehmet Baharoğlu ◽  
Gökay Nemli ◽  
Bünyamin Sarı ◽  
Nadir Ayrilmis ◽  
Selahattin Bardak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Contact Angle ◽  
Physical And Mechanical Properties ◽  
Formaldehyde Emission ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Quality Properties ◽  
Application Technique ◽  
Wood Particles

AbstractThe main objective of this study was to investigate the effect of paraffin application technique on the quality properties of particleboard. The paraffin was applied to the wood particles in three different techniques: (1) before resination, (2) after resination, and (3) with resin. The modulus of rupture, modulus of elasticity, internal bond strength, thickness swelling, surface roughness parameters, contact angle, and formaldehyde emission of the boards were determined. Statistical analysis showed that paraffin application technique had a significant influence on all properties of particleboards. The boards made using technique (1) had the highest mechanical properties and lowest surface roughness, formaldehyde emission and contact angle values. The worst properties were obtained from the board made using technique (2).

scholarly journals Thermal conductivity of different bio-based insulation materials

Les/Wood ◽  
2021 ◽  
Vol 70 (1) ◽  
Author(s):  
Sergej Medved ◽  
Eugenia Mariana Tudor ◽  
Marius Catalin Barbu ◽  
Timothy M. Young
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Raw Materials ◽  
Single Layer ◽  
Target Thickness ◽  
Wood Chips ◽  
Full Potential ◽  
Spruce Wood ◽  
Wood Residues ◽  
Wood Particles

To achieve the zero-waste goal as well as sustainability, the use of the raw materials, especially those from nature, and wood in particular, has to be smart, meaning that the resource has to be used to its full potential. Since wood-based industry is associated with high intensity and the generation of a relatively large amount of residues, those residues should be used for the production of useful products, otherwise they will easily be classified as waste and afterwards used as a source of energy. To present a possible solution for wood residues like wood chips, wood particles and bark, we investigated the possibility of using wood and bark residues as constituents for the production of single layer insulation panel with a target thickness of 40 mm and target density of 0.2 g·cm-3. Thermal conductivity was determined using the steady state principle at three different temperature settings. The average thermal conductivities were determined between 49 mW·m-1·K-1 and 74 mW·m-1·K-1. The highest values were determined at boards made from bark, which also had the highest density (0,291 g·cm-3), while the lowest thermal conductivity was observed for boards made from spruce wood particles.

Mechanical and Fungicidal Properties of approximately 100 Years Old Oak, Beech and Spruce Wood Beams

2013 ◽  
Vol 778 ◽  
pp. 159-166
Author(s):  
Nejc Thaler ◽  
Miha Humar
Keyword(s):  
Mechanical Properties ◽  
Beech Wood ◽  
Time Frame ◽  
Oak Wood ◽  
Spruce Wood ◽  
Standard Procedures ◽  
Wood Beams ◽  
English Oak ◽  
Preliminary Study ◽  
Over Time

The aim of this preliminary study was to investigate differences in mechanical and fungicidal properties of three different wood species (English oak (Quercus sp.), common beach (Fagus sylvatica) and Norway spruce (Picea abies)) specimens that were in indoor use for several decades, compared to control specimens of freshly cut timber. The collected material was cut to smaller specimen and conditioned in standard climate prior to further analysis. Mechanical, fungicidal, and sorption properties were determined according to the standard procedures. Our results show that mechanical properties of oak wood do not deteriorate in the investigated time frame. On the other hand, resistance of the wood against fungi decreases over time. The reason for this is yet to be confirmed, it could be due to the degradation of secondary metabolites. Similar results were observed for spruce wood as well. There were no statistically significant differences in mechanical properties of old and new spruce wood. In contrary to oak wood, there were also no significant differences in fungicidal properties, considering that spruce wood has lower durability than oak wood. Same as with oak wood, G. trabeum was found to be the most aggressive fungus. Ageing of beech wood resulted in a big drop in all of the tested mechanical properties, but showed no significant differences in fungicidal properties. Here is where the low durability of beech wood really shows. The old beech wood specimens were moderately deteriorated by insects and fungi, which was the reason for loss of bending and compressive strength.

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI
Keyword(s):  
Mechanical Properties ◽  
Double Layer ◽  
Starch Content ◽  
Single Layer ◽  
Double Layers ◽  
Coated Paper ◽  
Coated Papers ◽  
Coating Layers ◽  
Scanned Images ◽  
Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

scholarly journals Treatment of wood with atmospheric plasma discharge: study of the treatment process, dynamic wettability and interactions with a waterborne coating

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jure Žigon ◽  
Matjaž Pavlič ◽  
Pierre Kibleur ◽  
Jan Van den Bulcke ◽  
Marko Petrič ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Treatment Process ◽  
Beech Wood ◽  
Treated Wood ◽  
Plasma Discharge ◽  
Contact Angles ◽  
Atmospheric Plasma ◽  
Waterborne Coating ◽  
Spruce Wood ◽  
The Impact

AbstractPlasma treatment is becoming a mature technique for modification of surfaces of various materials, including wood. A better insight in the treatment process and the impact of the plasma on properties of wood bulk are still needed. The study was performed on Norway spruce and common beech wood, as well as their thermally modified variations. The formations of the airborne discharge, as well as mass changes of the treated wood, were monitored. The impact of such treatment on wood-coating interaction was investigated by evaluating the dynamic wettability and penetration into wood. At the wood surface, plasma streamers were observed more intense on denser latewood regions. Wood mass loss was higher with increasing number of passes through the plasma discharge and was lower for thermally modified wood than for unmodified wood. Plasma treatment increased the surface free energy of all wood species and lowered the contact angles of a waterborne coating, these together indicating enhanced wettability after treatment. Finally, the distribution and penetration depth of the coating were studied with X-ray microtomography. It was found that the coating penetrated deeper into beech than into spruce wood. However, the treatment with plasma increased the penetration of the coating only into spruce wood.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

Ab Initio Calculation of Mechanical Properties of Stacking Fault in 3C-SiC: Effect of Stress and Doping

2012 ◽  
Vol 717-720 ◽  
pp. 415-418
Author(s):  
Yoshitaka Umeno ◽  
Kuniaki Yagi ◽  
Hiroyuki Nagasawa
Keyword(s):  
Mechanical Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Stacking Faults ◽  
Single Layer ◽  
Local Strain ◽  
Density Functional Theory Calculations ◽  
Stacking Fault ◽  
Functional Theory ◽  
N Doping

We carry out ab initio density functional theory calculations to investigate the fundamental mechanical properties of stacking faults in 3C-SiC, including the effect of stress and doping atoms (substitution of C by N or Si). Stress induced by stacking fault (SF) formation is quantitatively evaluated. Extrinsic SFs containing double and triple SiC layers are found to be slightly more stable than the single-layer extrinsic SF, supporting experimental observation. Effect of tensile or compressive stress on SF energies is found to be marginal. Neglecting the effect of local strain induced by doping, N doping around an SF obviously increase the SF formation energy, while SFs seem to be easily formed in Si-rich SiC.

scholarly journals Analysis of Different Complex Multilayer PACVD Coatings on Nanostructured WC-Co Cemented Carbide

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 823
Author(s):  
Danko Ćorić ◽  
Mateja Šnajdar Musa ◽  
Matija Sakoman ◽  
Željko Alar
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Base Material ◽  
Single Layer ◽  
Production Costs ◽  
Structural Defects ◽  
Cemented Carbides ◽  
Material System ◽  
Tin Coating ◽  
Ticn Coating

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion.

scholarly journals Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cross Section ◽  
Negative Impact ◽  
Tensile Tests ◽  
Thermal Recovery ◽  
Bending Test ◽  
Small Scale ◽  
Spruce Wood ◽  
The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

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