Amorphous Silica Micro Powder Additive Influence on Bending Strength of One-Ply Particle Board

2016 ◽  
Vol 706 ◽  
pp. 82-85 ◽  
Author(s):  
Aleksandr Vasilyevich Pitukhin ◽  
Gennady Nikolaevich Kolesnikov ◽  
Nikolai Gennadievich Panov ◽  
Sergey Borisovich Vasilyev
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Specific Surface ◽  
Amorphous Silica ◽  
Bending Strength ◽  
Breaking Point ◽  
Formaldehyde Resin ◽  
Particle Board ◽  
Hardwood Species ◽  
Additive Influence

The methods and results of experimental investigation on the additive influence of amorphous silica micro powder when mixed in the glue for one-ply particle board are presented in the article. Wooden particles of coniferous and hardwood species as well as glue solution based on carbamide-formaldehyde resin were used for boards manufacturing. The amorphous silica micro powder contained particles 8 μm by the size and specific surface 120...400 m2/g was used in the experiment. The samples were tested to determine their physical-mechanical properties. It was found that 1 % amorphous silica micro powder additive increases the breaking point of one-ply particle board under bending strength by 43%.

Shungite Nanopowder as a Modificator of Mechanical Properties and Water Absorption for Three-Ply Particle Board

2016 ◽  
Vol 860 ◽  
pp. 73-77 ◽  
Author(s):  
Sergey Borisovich Vasilyev ◽  
Gennady Nikolaevich Kolesnikov ◽  
Aleksandr Vasilyevich Pitukhin ◽  
Nikolai Gennadievich Panov ◽  
Vadim Kostyukevich
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Water Absorption ◽  
Bending Strength ◽  
Wood Particle ◽  
Breaking Point ◽  
Experimental Investigations ◽  
Formaldehyde Resin ◽  
Particle Board ◽  
Thickness Swelling

The article presents the methods and the results of the experimental investigation of the additive influence of shungite nanopowder when mixed in the glue for three-ply particle board. The hypothesis of shungite nanopowder influence on physical-mechanical properties, water absorption and thickness swelling of wood particle board was formulated. The results of experimental investigations proved that the optimum shungite nanopowder quantity in glue solution makes up about 10 % of absolutely dry resin mass. Wooden particles of aspen and coniferous species, as well as glue solution based on carbamide-formaldehyde resin, were used in boards manufacturing. The samples were tested in order to determine physical-mechanical properties. It was found out that the 10 % shungite nanopowder additive increases the breaking point of three-ply particle board under bending strength by 18.3-25.7 %, the breaking point of three-ply particle board under tension perpendicular to the face of board by 7.5-11.7 %. As the result of experimental investigation it was found out that the 10 % shungite nanopowder when mixed in the glue decreases water thickness swelling of three-ply particle board up to 14.2 % and water absorption by 10.6-20.1 %. The shungite nanopowder powder contained particles of 50...100 nm in size and specific surface of 120 m2/g. In the course of the experiment three-ply particle boards were used with the thickness of 15.6 mm.

scholarly journals The effect of mat layers moisture content on some properties of particleboard

2019 ◽  
Vol 70 (3) ◽  
pp. 221-228
Author(s):  
Abdullah Istek ◽  
Ismail Ozlusoylu
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Formaldehyde Resin ◽  
Internal Bonding ◽  
The Core ◽  
Internal Bonding Strength

In this study, the effect of mat moisture content on the physical and mechanical properties of particleboard was investigated. The experimental boards were produced by using 40 % softwood, 45 % hardwood chips, and 15 % sawdust. The formaldehyde resin/adhesive was used in three-layers (bottom-top layer 12 %, core layer 8 %). Multi-opening press was used during manufacturing the experimental particleboards. The physical and mechanical properties of boards obtained were identified according to the TS-EN standards. The optimum core layer moisture content was determined as 6 % and 7 % according to the results, whereas the moisture content of bottom and top layers was 14 %. Under these moisture content conditions, the bending strength was found to be 13.3 N/mm², the modulus of elasticity in bending 2466 N/mm², and internal bonding strength 0.44 N/mm². The optimum bottom-top layer moisture content was determined to be between 13 % and 15 % and 6.5 % for the core layer.

scholarly journals Tensile and Impact Bending Properties of Chemically Modified Scots Pine

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 84 ◽  
Author(s):  
Susanne Bollmus ◽  
Cara Beeretz ◽  
Holger Militz
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Maximum Load ◽  
Solution Concentration ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Chemically Modified ◽  
Impact Bending

This study deals with the influence of chemical modification on elasto-mechanical properties of Scots pine (Pinus sylvestris L.). The elasto-mechanical properties examined were impact bending strength, determined by impact bending test; tensile strength; and work to maximum load in traction, determined by tensile tests. The modification agents used were one melamine-formaldehyde resin (MF), one low molecular weight phenol-formaldehyde resin, one higher molecular weight phenol-formaldehyde resin, and a dimethylol dihydroxyethyleneurea (DMDHEU). Special attention was paid to the influence of the solution concentration (0.5%, 5%, and 20%). With an increase in the concentration of each modification agent, the elasto-mechanical properties decreased as compared to the control specimens. Especially impact bending strength decreased greatly by modifications with the 0.5% solutions of each agent (by 37% to 47%). Modification with DMDHEU resulted in the highest overall reduction of the elasto-mechanical properties examined (up to 81% in work to maximum load in traction at 20% solution concentration). The results indicate that embrittlement is not primarily related to the degree of modification depended on used solution concentration. It is therefore assumed that molecular size and the resulting ability to penetrate into the cell wall could be crucial. The results show that, in the application of chemically modified wood, impact and tensile loads should be avoided even after treatment with low concentrations.

STUDY OF THE INFLUENCE OF STABILIZERS ON THE PROPERTIES OF CARBAMIDE FOR-MALDEHYDE BINDER AND FC PLYWOOD

2020 ◽  
Vol 10 (1) ◽  
pp. 136-143
Author(s):  
A. Fedotov ◽  
Tat'yana Vahnina ◽  
Andrey Titunin ◽  
Aleksandr Sviridov
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Strength Reduction ◽  
Cohesive Strength ◽  
Urea Formaldehyde Resin ◽  
Strength Characteristics ◽  
Formaldehyde Resin ◽  
Glycerol Mono

The problem of stabilizing the properties of the urea-formaldehyde binder during storage is relevant for both glued products and resins. Changing the performance of the resin during storage makes it difficult to apply a binder and leads to a deterioration in the physical and mechanical properties of plywood. The effect of glycerol, mono- and triethanolamine, as well as a mixture of glycerol and monoethanolamine on the nominal viscosity of the resin after 56 days of storage, has been studied. The use of glycerol and monoethanolamine (including in the complex) reduces the nominal viscosity of the resin by 13.5-24.8%. The use of triethanolamine as a stabilizer makes it possible to reduce the nominal viscosity by 35% in comparison with the index of an unstabilized oligomer. Mechanical properties of FC plywood based on the stabilized and unstabilized binder has been studied. It was found that glycerol additive (or glycerol in combination with monoethanolamine) significantly reduces strength characteristics of plywood, which makes it irrational to use these stabilizers. The addition of 0.2% triethanolamine to CFS allows a 35% reduction in the nominal viscosity of the resin, while the cohesive strength of the binder decreases by 1.5%. The result is within the framework of the dispersion of the indicator, i.e. strength reduction is negligible. The static bending strength of plywood with a stabilized triethanolamine binder is more important than that of control specimens without the addition of stabilizers. The results of the study enable to recommend the addition of triethanolamine in an amount of 0.2% by weight of urea-formaldehyde resin as a rational stabilizer

scholarly journals Effects of the thickness of rotary-cut veneers on properties of plywood sheets. Part 2. Physical and mechanical properties of plywood materials

2012 ◽  
Vol 52 (No. 3) ◽  
pp. 118-129
Author(s):  
J. Hrázský ◽  
P. Král
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Institutional Research ◽  
Nominal Thickness

The second part of the paper summarizes results of an institutional research aimed at the determination of physical and mechanical properties of different sets of plywood sheets pressed under different conditions. The first part dealt with the determination of compressibility or values of decreasing the thickness of pressed plywood sheets. In this second part, results are summarized of the analysis of physical and mechanical properties of the set of whole-beech plywood sheets of the nominal thickness of veneers amounting to 1.5 mm. The plywood sheets were manufactured as seven-ply and urea-formaldehyde resin DUKOL S was used for their production. The sheets were pressed using a pressure of 1.5 and 1.7 MPa. Following parameters were analyzed: moisture, density, bending strength, MOE in bending and shear strength.

Properties of Silica Ceramic Made from Amorphous Silica

2010 ◽  
Vol 434-435 ◽  
pp. 838-839 ◽  
Author(s):  
Cai Fen Wang ◽  
Jia Chen Liu ◽  
Ji Ping Guo ◽  
Di Song ◽  
Wen Jun Lian
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Amorphous Silica ◽  
Glassy Phase ◽  
Bending Strength ◽  
Coal Fly Ash ◽  
Slip Casting ◽  
Fused Silica ◽  
Casting Method ◽  
Silica Ceramic

The mixture of amorphous silica extracted from coal fly ash and fused silica was used to prepare density silica ceramic through slip-casting method. The XRD results showed that a large amount of cristobalite was formed at 1300°C which can weaken mechanical properties. The SEM results showed that glassy phase present from fused silica promoted ceramic densification. According to the experiment results, it was found that the bending strength was highest when mixing 65wt% fused silica and sintering at 1200°C for 4 hours.

scholarly journals Effect of Different Hardwood Species and Lay-Up Schemes on the Mechanical Properties of Plywood

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 649 ◽  
Author(s):  
Heikko Kallakas ◽  
Anti Rohumaa ◽  
Harti Vahermets ◽  
Jaan Kers
Keyword(s):  
Mechanical Properties ◽  
Wood Species ◽  
Bending Strength ◽  
Processing Parameters ◽  
Strength Properties ◽  
Product Density ◽  
Black Alder ◽  
Hardwood Species ◽  
Birch Veneer

In Estonia, hardwoods form approximately 50% of all forest area, where the main species are birch (30%), gray alder (9%), aspen (6%) and black alder (4%). Birch has been extensively used by the veneer-based industry, but species like black alder, gray alder and aspen have not been commonly used by the veneer-based products industry due to the lower quality of this resource. The aim of this research is to determine the effect of different lay-up schemes and usages of gray alder, black alder and aspen on the mechanical properties of plywood, by replacing birch veneer in the plywood core with alternative wood species. The main veneer and plywood characteristics will be evaluated according to the current standards, e.g., veneer strength perpendicular to grain, plywood bonding and bending strength, and modulus of elasticity. All processing parameters will be kept similar to those used generally by birch plywood manufacturers. The results showed that birch and black alder plywood panels had generally the highest bending strength properties, followed by grey alder and aspen. It was also found that, for proper gluing, birch veneers had the lowest glue consumption, 152 g/m2, and aspen had the highest glue consumption, 179 g/m2. It was found that when lower density wood was used in the plywood, the product density increased. Low density wood veneers had higher glue consumption, and also higher compaction in thickness than birch veneers under the same pressure. Overall, it was shown that the wood species used in this study have slightly lower strength properties, but with proper lay-up schemes, these wood species could be successfully used by the veneer-based products industry.

scholarly journals Furan resin as potential substitute for phenol-formaldehyde resin in plywood manufacturing

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 2727-2739
Author(s):  
Anca Maria Varodi ◽  
Emanuela Beldean ◽  
Maria Cristina Timar
Keyword(s):  
Mechanical Properties ◽  
Water Resistance ◽  
Bending Strength ◽  
Reference Product ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Furan Resin

Replacement of phenol-formaldehyde with a mixed furan resin is considered in this work as a means to improving plywood properties made with urea-formaldehyde-based adhesive currently made with an addition of phenol-formaldehyde resin. Previous research showed that the furan resins can improve water resistance and can provide long stability for the glue line. Plywood was manufactured with modified adhesives and characterized in comparison with a reference product. Thickness, physical properties (moisture content, density, and total water absorption), mechanical properties (shearing strength, bending strength, and elasticity modulus in bending), and formaldehyde emission were determined according to standardized methods. The results indicated that the addition of furan resin enhanced the water resistance by 43% and formaldehyde emission is according to E1 class. Also, the mechanical properties were improved; the shear strength for the adhesive composition with furan resin was increased by 14 to 30% compared with the reference product, depending on the testing conditions.

scholarly journals Properties of High-Density Fiberboard Bonded with Urea–Formaldehyde Resin and Ammonium Lignosulfonate as a Bio-Based Additive

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2775 ◽  
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Neno Trichkov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Thermal Analyses ◽  
Formaldehyde Emission ◽  
High Density ◽  
Formaldehyde Resin ◽  
Gravimetric Analysis ◽  
Wood Fibers ◽  
Uf Resin

The potential of ammonium lignosulfonate (ALS) as an eco-friendly additive to urea–formaldehyde (UF) resin for manufacturing high-density fiberboard (HDF) panels with acceptable properties and low free formaldehyde emission was investigated in this work. The HDF panels were manufactured in the laboratory with very low UF resin content (4%) and ALS addition levels varying from 4% to 8% based on the mass of the dry wood fibers. The press factor applied was 15 s·mm−1. The physical properties (water absorption and thickness swelling), mechanical properties (bending strength, modulus of elasticity, and internal bond strength), and free formaldehyde emission were evaluated in accordance with the European standards. In general, the developed HDF panels exhibited acceptable physical and mechanical properties, fulfilling the standard requirements for HDF panels for use in load-bearing applications. Markedly, the laboratory-produced panels had low free formaldehyde emission ranging from 2.0 to 1.4 mg/100 g, thus fulfilling the requirements of the E0 and super E0 emission grades and confirming the positive effect of ALS as a formaldehyde scavenger. The thermal analyses performed, i.e., differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and derivative thermogravimetry (DTG), also confirmed the main findings of the research. It was concluded that ALS as a bio-based, formaldehyde-free adhesive can be efficiently utilized as an eco-friendly additive to UF adhesive formulations for manufacturing wood-based panels under industrial conditions.

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