Antibacterial efficiency of silver and zinc-oxide nanoparticles in acrylate coating for surface treatment of wooden composites

The paper deals with antibacterial effect of silver and zinc-oxide nanoparticles in acrylic coatings applied at treatment of commercial wooden composites – particleboard and medium density fibreboard. The silver nanoparticles usually better suppressed the activity of the Gramnegative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus already at lower concentrations (0.04 – 0.2 mg Ag/100 g of coating) as the zinc-oxide nanoparticles used in 100-times higher concentrations (4 – 20 mg ZnO/100 g of coating). Both types of applied nanoparticles at higher concentrations had a more apparent efficiency against E. coli comparing to S. aureus.

Effect of hygroscopicity of fire retardant on hygroscopicity of fire retardant bamboo chips

This paper presents a study on the effect of hygroscopicity of fire retardant on the hygroscopicity of fire retardant materials (bamboo chips). The results showed that the hygroscopicity of fire retardant and fire retardant bamboo chips increased with increasing fire retardant concentration, and the suitable range of fire retardant concentration is 20- 30 %; the hygroscopicity of fire retardant and fire retardant bamboo chips increased with the increasing of drug loading rate of fire retardant bamboo chips, and the suitable drug loading rate is 10.2 %; the hygroscopicity of fire retardant bamboo chips increased with the increase of the hygroscopicity of fire retardant, and the hygroscopicity of fire retardant bamboo chips is smaller when treated with the fire retardant whose water absorption rate less than 18 %.

The effect of the relaxation time on the mechanical properties of longitudinally compressed wood

Longitudinal compression makes natural wood easier to bend. The relaxation after compression results in much improved bending properties. During a bending test, the maximum deflection increases with the relaxation time, while the needed force to reach the same deflection decreases, similarly to the modulus of elasticity (MoE). The modulus of rupture (MoR) of the compressed wood does not change considerably compared to the untreated wood, except at the long-time relaxed samples. The ideal relaxation time is 1 minute. After that the change of the important properties slows down. Of course with special demands, the relaxation time can be also very long. In this case the process leads to a wood sample with pronounced flexible properties. Samples were left to rest between normal circumstances for 1 day, but this resting period did not have a significant effect on its mechanical properties.

Visual simulation on dynamic accumulation of the differentiating xylem cells

This study describes the dynamic accumulation of xylem cells of the fast-growing Populus×euramericana cv. ‘74 /76’ during the growth phase by the methods of microscopy analysis and computer simulation technology. In order to show a more intuitive accumulation and dynamic variation process of cells in different periods, the computer simulation software was used to simulate the accumulation process of cambium and xylem cells according to the data of the accumulation and anatomical characteristics. The dynamic accumulation process of the xylem cells was visually displayed by the computational simulation technology during the active period.

The strength and termite resistance characteristics of fiberboards produced from the renewable bamboo biomass

This study investigated the physical, chemical, and termite resistance characteristics of fiberboard made from the trunk fiber of five bamboo species (Giganto chloaapus, Gigantochloa atroviolacea, Giganto chloaatter, Dendrocalamus asper, and Bambusa vulgaris) and its suitability as a construction material. Five types of fiberboard with a target density of 0.8 g. cm-3 were prepared by using a hot-pressing system at a temperature of 180°C for 15 minutes. Fiberboards were examined for the bonding strength, lignin content, and morphological characteristics. Termite resistance characteristic of fiberboards was performed by three-week laboratory feeding trials against Coptotermes formosanus Shiraki and Incistermes minor Hagenas described in Japanese International Standard (JIS) K. 1571. The results showed that the strongest bonding characteristic was B. vulgarisfiberboard, followed by G. apus, G. atroviolacea, and G. atter. The highest lignin content presented in G. atter (29.23%), followed by G. atroviolacea (28.78%), D. asper (26.60%), G. apus (26.48%), and B. vulgaris (23.87%). The lowest weight loss of bamboo fiberboard after termites’ assay was D.asper (7%). In conclusion, the fiberboard made from the fiber of bamboo trunk waste hasthepotency as a promising building material. However, alltypes of bamboo fiberboard would require additional protection for applicationin the area with a high number of termite nests.

Degradation features of archaeological wood surface to deep inside a case study on wooden boards of marquis of haihun’s outer coffin

Although researches have been carried on the bio-chemical deterioration of archaeological wood, still the degradation of archaeological wood is so complicated to fully understand. One essential question is how archaeological wood of large volume would degrade from surface to deep inside and why. The recently unearthed outer coffin of Marquis of Haihun, buried for over 1800 years, gave us a great opportunity to investigate this question. The degradation features were analyzed with methods of optical microscopy, Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), viscosimetry, and determination of physical properties of wood. The results, including the microstructures of wood fibers, wood components, degree of polymerization and crystallinity of cellulose, and shrinkage of wood, unanimously show that the sapwood of the board is worst degraded, the surface layer of the heartwood is degraded to a higher extent than the inner part, and it tends to degrade more easily along the axial direction.

Waste agglomerated wood materials as a secondary raw material for chipboards and f ibreboards Part II. Preparation and characterisation of wood f ibres in terms of their reuse

The paper describes a process for the preparation of fibre from waste wood particleboards (PB), oriented strand chipboard (OSB) and medium density fibreboard (MDF). The purpose of recycling of agglomerated wood materials is to reuse them for the production of fibrous materials. The agglomerated materials disintegrated after the initial destruction were further processed under the specified conditions with respect to the moisture content, their type, adhesive used, and properties of final particles – wood chips. The obtained wood particles were characterized by the fractional composition of chips. The resulting chips were mechanically defibred with subsequent characterization of fiber obtained for its reuse in the manufacture of MDF. A quantity of formaldehyde released into the water when cooking waste MDF and PB was set up depending on the cooking time. Residual level of formaldehyde is the main chemical load that determines the amount of waste material that can be reused for production of new panels based on ureaformaldehyde adhesives.

Determination of leaching features of wood surfaces colored by eco-friendly red beetroot (Beta vulgaris) extract

The aim of this study to develop an eco-friendly wood stain and to determine the adsorption and desorption on surfaces. In this context; plant dyestuff was extracted from the red beetroot by using ultrasonic assisted method and applied to wood blocks of Turkish oriental beech, Scots pine, oak, and walnut with immersion (classic) and ultrasonic-assisted immersion methods. As mordants, ferrous sulphate, aluminum sulphate, copper sulphate, and vinegar were chosen. In the study, the effect of such parameters as the medium pH (3, 7 and 9), temperature (22°C and 40°C), velocity of agitation (10 and 30 rpm) in leaching was investigated. As a result of experiments; red beetroot extracts performed good desorption, vinegar and copper sulphate were reduced the best desorption on surfaces. Ultrasonic-assisted method was not affect the leaching performance positively, but general leaching results showed that red beetroot can be used for wood surface stain and they can be alternative to chemical dyes.

Analysis of cutting performance in high density fiberboard milling by ceramic cutting tools

In order to study the cutting performance of TiC reinforced Al2O3 ceramic cutting tools in milling high density fiberboard, the effects of cutting parameter on the cutting forces, tool wear and cutting quality were investigated. Under the condition of same average chip thickness, feed per tooth and geometry angles, firstly, the change rate of maximum cutting forces were higher than that of average cutting forces at two different cutting speeds, and the cutting forces at high speed cutting was less than that at low speed cutting. Secondly, the flank wear at high speed cutting was more pronounced than that at low speed cutting, whose abnormal wear were pull-out of grain, cracking, chipping and flanking. Thirdly, the machining quality at high speed cutting was better than that at low speed cutting. Fourthly, the tendencies of cutting forces, tool wear and surface roughness relative to cutting length were similar, but the change rates were different, especially at the initial stage. Finally, high speed cuttingare plausible to use in HDF processing, which not only improves machining quality, but also promotes production efficiency.

Organosolv pulping of Calotropis procera by mono ethanol amine

In this study, usage of mono ethanol amine (MEA) as an organic reagent was considered in pulping of Milkweed compared with alkaline non-friendly pulping methods including Kraft and Kraft-AQ and soda-AQ. In this case, monoethanolamine was added in various ratios i.e. 100, 75, 50, 37.5 and 25% in replacement with water (MEA-water pulping). Besides, anthraquinone was added in parallel with MEA-water treatments (MEA-water -AQ ) and its effect on pulp properties has been considered. The results indicated that replacement ratio of 75/25, 240 minutes of retention time and with0.1% usage of anthraquinone showed the optimum conditions based as yield and kappa number of the pulp samples. Moreover, at the same degree of delignification, the MEA pulps showed about 15-20% higher yield based on raw material. Total unbleached MEA pulp yield is very high, ranging between 48 to 54% with kappa number of 58. For Kraft, the yield varied between 38 to 43%.

Analysis of diagnostic methods for detecting the presence of gloeophyllum spp

The development of wood use as a renewable raw material for construction caused that can be also seen as the construction of bridge structures, which have to withstand the environment. It is a modern construction using LLD or replicas of historical buildings using RD. Many of these constructions, despite impregnation, are struggling with biological pests that greatly reduce their durability. Revealing of the most dangerous ones is complex and usually cost such amount of money. Diagnostic methods and their results are different. The article deals with the comparison of the diagnosis methods of wood decaying fungi from the family of Gloeophyllaceae to the real construction.

Technique to improve paint utilizing efficiency of wooden board during electrostatic spraying process

A technique to improve paint utilizing efficiency of wooden board during electrostatic spraying process was proposed. An experiment was carried out for verification of its feasibility. A finite element model for electric field between spray gun and wooden board was built by ANSYS software. Experimental results show that paint weight per square meter of wooden board surface after electrostatic spraying is increased significantly when the technique is used. Simulation results show that the electric field intensity between spray gun and wooden board is increased obviously when the technique is used.

Wood quality of Paraserianthes falcataria L. nielsen syn wood from three year rotation of harvesting for construction application

Paraserianthes falcataria is fast growing species that considered being potential lumber for construction application. The aim was to evaluate the effect of year rotation of harvesting on quality of Paraserianthes falcataria wood for construction application. Nine trees of Paraserianthes falcataria with harvesting rotation of 5, 7, and 9 years, were harvested from the private forest. Moisture content, specific gravity, shrinkage, MOE, MOR, and compressive strength parallel to grain were measured for wood quality parameters in accordance to JIS Z 2101. Durability test were conducted against dry wood termite (Criptotermes cynocephalus Light). The results showed that year harvesting of Paraserianthes falcataria influence significantly on specific gravity, and compressive strength parallels to grain. Paraserianthes falcataria wood is classified into strength class III-IV, which is properly used for light construction. To obtain optimum quality for construction purposes, Paraserianthes falcataria tree is recommended to be harvested in minimum harvesting rotation of 7 years.

Optimal design of stretchers positions of mortise and tenon joint chair

The chair joined by oval mortise-and-tenon was taken as a case. Then influences of two adjacent sides (side A and side B) stretcher positions on mechanical properties of chairs, including ultimate loading capacity, stiffness and strain distributions, were investigated through using experimental and numerical methods. Firstly, two factors and three levels experiments were conducted and analyzed by Finite Element Method (FEM) . The results showed that ultimate loading capacity of chairs decreased firstly and then increased with the growth of the height of stretchers positions. In addition, the stress concentration occurred at middle of side rails and joints of side rails, especially at the side B, while the stress at the middle of the leg was minimum. Besides, the higher the stretcher position of the side A was, the more harmonious the stress distributions of chair was, and the higher ultimate loading capacity and stiffness were. Moreover, the results of FEM were well consistence with those of experiments, and the errors were within 10%. Secondly, two factors and five levels numerical analysis was conducted to optimize the stretcher positions of chair by the FEM, and the results showed more boadly that the best stretchers positions of chair owning the highest loading capacity was not the only one. Finally, the relationship between ultimate loading capacity and stretcher positions was generated by using the response surface method, and the correlation coefficient was nearly 88%.

Hydrophobic properties of wood traeted with propolis-silane formulations

The study presents results of hydrophobic properties examination of Scots pine wood treated with a propolis extract and two propolis-silane formulations determined by contact angle analysis and water uptake test. From contact angles data the surface free energy and its shares as well as the work of adhesion were calculated and described in this paper. Treatment with the ethanolic extracts of propolis (EEP) and the propolis-silane formulations a water repellent property of treated wood when compared to control wood. Addition of silicon compounds to the propolis extract caused decreased of the water uptake and increased of the contact angle value of treated wood. The most effective hydrophobic effect was obtained using the impregnation with the formulation based on EEP and organosilanes: vinyltrimethoxysilane (VTMOS) and tetraethyl orthosilicate (TEOS).

Cultural and creative product design based on biology characteristics of wood

First, this article introduces the natural properties of wood. Wood not only has the unique wood texture, rich colours, but also has changeful shape and unique cultural attributes, what is why wood can be widely used in many fields. Secondly, the article briefly describes natural and cultural attributes, and analyzes the cultural connotation embodied in product design. The dual properties of wood meet the material and spiritual needs of people. Finally, by introducing the two cultural and creative products of writer designs to indicate the development of cultural products is a traditional material as well as the new era of the spiritual needs of the perfect combination of the way. It also plays a decisive role in reflect the wood for promoting cultural and creative product design.