Analysis of low requirement justification of the current standard for the strength of wood particle boards

Currently, wood particle boards made of crushed shavings are widely used in the production of cabinet furniture, despite their shortcomings. The volume of particle board production in Russia is constantly growing. The main disadvantages of the boards include their toxicity associated with the release of gas (formaldehyde) harmful to humans above the permissible level (PL = 0.01 mg/m3 of air), low strength properties (especially bending strength) and limited areas of application of the boards. If we trace the dynamics of the technical requirements for these properties of boards according to the standards, then the question arises - what is the reason for the decrease in the requirements for the strength of boards in bending and, in this regard, the limitation of the application areas of particle board? A regular decrease in the requirements in the newly introduced State Standards has been constantly occurring since 1977, but this is especially noticeable in the current 10632-2014 State Standard. This article focuses on the possible objective and subjective reasons for the low requirements of the current standard for the strength of wood particle board.

Pengaruh Kadar Perekat Terhadap Karakteristik Briket Arang Limbah Kayu Karet (Hevea brasiliensis Muell. Arg)

The study aimed to determine the effects of adhesive content on rubber wood charcoal briquette characteristics. Wood charcoal was produced using a double-drum retort kiln at > 500°C. Wood charcoals were crushed into powder and then mixed with tapioca adhesive of 5%, 10%, and 15%. The charcoal-adhesive mix was then pressed using a hydraulic press machine. For comparison, rubber wood biomass briquettes were also produced using wood particle-adhesive mix with similar adhesive content. Biomass and charcoal briquettes characteristics as physical properties (density and water absorption), chemical properties (ultimate analysis, and FTIR analysis) and energy properties (calorific value) were evaluated. The results showed that density ranged between 0.52-0.56 g/cm3, water absorption of 6.54-7.47%, C content of 82.67-84.41%, H content of 3.28-3.60%, N content of 0.67%-0.74%, and calorific value of 30.76-32.86 MJ/kg. The results of FTIR analysis showed changes in the spectrum of the wave band on the functional groups OH, CH, C≡H, C=C, and C=O, indicating the decomposition of the chemical components of rubber wood due to pyrolysis. The results prove that increasing the adhesive content can reduce the quality of briquettes. Based on physical, chemical, and energy properties, charcoal briquettes with 5% adhesive showed better characteristics than briquettes with 10% and 15% adhesive content, showing water absorption of 6.54%, C content of 84.41%, H content of 3.28%, and heating value of 32.86 MJ/kg. Keywords: adhesive content, charcoal briquette, pyrolysis, rubber wood waste, tapioca starch

Waste Wood Particles from Primary Wood Processing as a Filler of Insulation PUR Foams

A significant part of the work carried out so far in the field of production of biocomposite polyurethane foams (PUR) with the use of various types of lignocellulosic fillers mainly concerns rigid PUR foams with a closed-cell structure. In this work, the possibility of using waste wood particles (WP) from primary wood processing as a filler for PUR foams with open-cell structure was investigated. For this purpose, a wood particle fraction of 0.315–1.25 mm was added to the foam in concentrations of 0, 5, 10, 15 and 20%. The foaming course of the modified PUR foams (PUR-WP) was characterized on the basis of the duration of the process’ successive stages at the maximum foaming temperature. In order to explain the observed phenomena, a cellular structure was characterized using microscopic analysis such as SEM and light microscope. Computed tomography was also applied to determine the distribution of wood particles in PUR-WP materials. It was observed that the addition of WP to the open-cell PUR foam influences the kinetics of the foaming process of the PUR-WP composition and their morphology, density, compressive strength and thermal properties. The performed tests showed that the addition of WP at an the amount of 10% leads to the increase in the PUR foam’s compressive strength by 30% (parallel to foam’s growth direction) and reduce the thermal conductivity coefficient by 10%.

Effect of Wood-Fiber Geometry Size on Mechanical Properties of Wood-Fiber from Neolamarckia Cadamba Species Reinforced Polypropylene Composites

Using natural wood-fiber as reinforcement in commercial thermoplastics is gaining momentum due to its high specific properties and renewable resources. In this study, the effect of wood particle geometry size on mechanical properties of thermoplastics composite was investigated. The wood species that has been chosen is Kelempayan species (Neolamarckia cadamba) and reinforced with polypropylene using fiber geometry size of 75 and 250 ?m. Thermoplastic composites were produced from two types of ratio (30:70 and 10:90) between wood-fiber and polypropylene. Static bending and tensile strength were tested. The result showed that wood-fiber from 75 ?m geometry sizes with ratio of 30:70 between wood-fiber and polypropylene was most suitable in producing thermoplastic composites. The geometry sizes of wood particle as well as the ratio between wood-fiber and polypropylene were found to influence the mechanical properties of the thermoplastic composites.

Mechanical Properties of Commercial Particleboard from Rubberwood (Hevea Brasiliensis) and Recycle Mix-Tropical Wood with Different Board Density

In this study, mechanical properties of commercially manufactured hybrid particleboard from mix-tropical wood and rubberwood with four different densities at 25mm thickness have been investigated. The particleboard sample cutting and testing was in accordance to EN312:2013. The density of particleboard is identified with interval of 10kg/m3 for different densities which include 660kg/m3, 670kg/m3, 680kg/m3 and 690kg/m3. Particleboards were made with the ratio of 40:60 for mix-tropical wood particle and rubberwood particle respectively. The particleboards were prepared with urea formaldehyde (UF) with E1 formulation with addition of wax and hardener. Increment of 10kg/m3 density for each particleboard led to increase in internal bonding (IB), bending testing include modulus of rupture (MOR) and modulus of elasticity (MOE), surface soundness (SS) and screw edge (SE) withdrawal. It was found that with board increment of 10kg/m3, the improvement was not statically significant except that for MOR. All panels met the minimum requirements of standard.

Investigation of the Rate of Vacuum-Conductive Drying of Wood-Particle Panels Based on Polyvinyl Alcohol

Wood composites are promising construction and finishing materials that offer the best properties of both wood and polymers. With the industry's need to use low-toxic adhesives in view, one of the ways to ensure the environmental friendliness of composites is the use of polyvinyl alcohol as a binder. In this respect, in order to streamline production, both in terms of reducing energy consumption and improving the quality of the final product, it is vital to choose the drying rate when pressing panels. The paper presents the results of a study of the process of vacuum-conductive drying of eco-friendly polyvinyl alcohol (PVA)-based wood-particle material. It was found that the composite samples with a PVA content of 40% in terms of physical and mechanical parameters (ultimate bending strength and ultimate tensile strength perpendicular to the panel face) fully comply with the established standards. The study provided the values of drying rate depending on 5 factors. The multi-factor regression analysis method was used to derive equations that determine the drying rate of polyvinyl alcohol-based wood-particle panels for two humidity intervals (above and below the cell walls humidification limit), taking into account the properties of different classes of bodies that make up the composite.

Preparing Carbon Bactericide Sorbents from Waste Wood Boards

The paper presents the results of research on the disposal of large-tonnage composite polymer waste - wood-particle boards by the method of catalytic low-temperature pyrolysis for preparation of carbon materials. Salts and nickel were used as catalysts. The influence of temperature, mass ratio “waste: metal ions” on the yield and properties of carbonizate was investigated. It was found that when pyrolysis is carried out at a temperature of 600 °C for 30 min in the presence of catalysts, carbon materials are formed with a developed porous structure and high sorption activity with respect to the methylene blue dye and iodine. It is shown that the metals catalyzing pyrolysis are incorporated into the processes of the forming sorbent. The studies carried out on the treatment of biologically active river water showed a high bactericidal ability of the obtained samples of sorbents. The developed method of catalytic pyrolysis of waste made it possible to obtain bactericidal carbon sorbents that can be used for deep additional purification and disinfection of biologically treated wastewater.

Influence of Adding Lignin and Wood as Reactive Fillers on the Properties of Lightweight Wood–Polyurethane Composite Foams

In this study, bio-based rigid polyurethane (PU) composite foams were prepared by a free-rising method, with the addition of wood particles (10 and 20 weight percent by the foam mass) and kraft lignin (5 and 10 weight percent by the polyol mass) as reactive reinforcing fillers. The resultant PU composites were evaluated for chemical structure, density, morphology, compressive properties, water uptake, and thermal stability. Fourier-transform infrared analysis confirmed the formation of characteristic urethane bonds in all foam samples. The foaming process was slowed down by the incorporation of lignin and wood particles. The apparent density of lignin-incorporated wood–PU composite foam ranged between 77 and 105 g/cm3. Compared with the neat PU foam, addition of wood particle resulted in decreased compressive properties and increased water uptake of the foams, whereas incorporation of lignin had a positive effect on the compressive properties and water resistance. In general, the PU foam sample with the incorporation of only 5 percent lignin (PUL5) exhibited the optimal physical–mechanical properties, with the compressive strength increased by 74 percent and 24-hour water uptake decreased by 28 percent compared with the control PU foam. Thermogravimetric analysis showed that the incorporation of lignin and wood particles did not significantly affect the thermal degradation pattern of foam but rather increased the mass of char residue.

Optimasi Produksi Asap Cair Dari Kayu Medang (Cinnamomum sp.) Menggunakan Metode Permukaan Respon

In this work medang wood (Cinnamomum spp.) was pyrolyzed to produces wood vinegar. The effect of several parameters including the wood particle size, pyrolysis temperature, and pyrolysis time on the pyrolysis efficiency was tested to identify the optimal wood vinegar production conditions. The efficient response surface methodology (RSM) with the Box-Behnken design (BBD) was used for modeling and optimization of the process parameters. RSM used three variable designs namely particle size of wood of 2.38, 3.36, and 4.76 mm, respectively, pyrolysis temperature of 370, 400 and 430°C, respectively, and pyrolysis times 90, 120 and 150 minutes, respectively, with the total of 15 experimental runs. The responses of the BBD fitted with a second-order polynomial equation, illustrating the wood vinegar yield was Y = 15.20 + 0.31 X1 + 5.00 X2 + 0.48 X3 – 1.84 X12 – 1.18 X22 + 0.63 X1.X2 + 0.35 X1.X3 + 0.31 X2.X3 – 0.27 X3.X3. The optimal conditions found to be at the particle size of wood, pyrolysis temperature, and pyrolysis time were 4.76 mm, 475 °C, 195 minutes, respectively, and yield of wood vinegar was 22.90%.