Changing wood texture with combination of selective treatment and pressing

Abstract Structural and anatomical models of alder wood have been developed on the basis of technical and physical models of wood. The models enable to solve the problem of penetrating changes in wood texture by combining selective treatment (impregnation) with two wood colouring agents in different directions of anisotropy, followed by uneven pressing. Specimens with the texture of mahogany, rosewood, walnut, etc have been obtained. Alder wood is pressed at an angle of 45° to the radial direction to obtain the texture of mahogany, at an angle of 90° – for a texture of rosewood. At the same time, physical and mechanical properties of modified wood correspond to similar indicators of wood of these species. The study of macro-and microstructure of pressed wood suggests that texture of the obtained material corresponds to the texture of rosewood and mahogany. It is possible to imitate any species of valuable wood using the obtained structural models and the developed techniques.

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Enhancement of the physical and mechanical properties of wood using a novel organo-montmorillonite/hyperbranched polyacrylate emulsion

Holzforschung ◽

10.1515/hf-2020-0042 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Jianfeng Xu ◽

Xiaoyan Li ◽

Ling Long ◽

Ru Liu

Keyword(s):

Mechanical Properties ◽

Cell Wall ◽

Pinus Radiata ◽

Wood Sample ◽

Wood Cell Wall ◽

Physical And Mechanical Properties ◽

Radiata Pine ◽

Compact Structure ◽

Populus Cathayana ◽

Modified Wood

AbstractIn this work, a novel waterborne hyperbranched polyacrylate (HBPA) dispersed organo-montmorillonite (OMMT) emulsion was synthesized and used for the treatment of wood in a vacuum environment in order to enhance the physical and mechanical properties of the wood. The sapwood of Cathay poplar (Populus cathayana Rehd.) and Radiata pine (Pinus radiata D.Don) were used as the samples for experimentation. The results showed that the physical and mechanical properties of the wood improved significantly due to the successful penetration of the OMMT and HBPA into the wood cell wall. From it was also observed that OMET completely exfoliated from the HBPA matrix and formed a hydrophobic film covering on the inside walls of the cell lumen. Further, it was observed that the poplar sample displayed better mechanical properties than the pine sample because the pine has a more compact structure when compared to poplar and contains rosin. Furthermore, it was also observed that the mechanical properties of the modified wood sample gradually improved with an increase in the concentration of the emulsion. However, excessive concentration (>4 wt%) did not lead to further improvement.

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Physical and Mechanical Properties of Chemically Modified Wood

Chemical Modification of Lignocellulosic Materials ◽

10.1201/9781315139142-12 ◽

2017 ◽

pp. 295-310

Author(s):

Roger M. Rowell

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Chemically Modified ◽

Modified Wood

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Effect of thermomechanical densification of pine wood (Pinus sylvestris L.) on cutting forces and roughness during milling

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0015.2330 ◽

2021 ◽

Vol 113 ◽

pp. 36-42

Author(s):

Barbara Białowąs ◽

Karol Szymanowski

Keyword(s):

Mechanical Properties ◽

Surface Roughness ◽

Statistical Analysis ◽

Pinus Sylvestris ◽

Cutting Forces ◽

Physical And Mechanical Properties ◽

Milling Process ◽

Pine Wood ◽

Roughness Index ◽

Modified Wood

Effect of thermomechanical densification of pine wood (Pinus sylvestris L.) on cutting forces and roughness during milling. The paper presents the results of research concerning the assessment of machinability of pine wood thermomechanically compacted. The assessment was made on the basis of the cutting forces and surface roughness after the milling process. Selected properties of native and modified wood were examined. Based on the research, it was found that compacted wood is characterized by higher cutting forces during milling. The surface quality after milling was examined and the roughness index Ra values were determined. The research shows that the modified wood is characterized by a lower Ra value both along and across the grain. Statistical analysis showed that the modification had a statistically significant effect on the values of cutting forces and the physical and mechanical properties of the tested wood.

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Preliminary Study on the Physical and Mechanical Properties of Poplar Wood Modified by Waterborne Glucose Silicone Resin

10.20944/preprints202012.0251.v1 ◽

2020 ◽

Author(s):

Qiangqiang Liu ◽

Haojia Du ◽

Wenhua Lyu

Keyword(s):

Mechanical Properties ◽

Cell Wall ◽

Mass Fraction ◽

Untreated Wood ◽

Physical And Mechanical Properties ◽

Silicone Resin ◽

Poplar Wood ◽

Characteristic Structure ◽

Organic Hybrid ◽

Modified Wood

In order to improve the performance of soft plantation wood, an environmentally friendly inorganic-organic hybrid wood modifier was developed. First, using urea and melamine as crosslinking agents, the waterborne glucose silicone resin (MUG) was prepared with glucose under the catalysis of inorganic acid and metal ions. Then MUG resin was diluted to 10% and 20% mass fraction, and compounded with sodium silicate (S) of 20% and 10% mass fraction, so the inorganic-organic hybrid G10S20 and G20S10 wood modifier were obtained respectively. Then plantation poplar wood (Populus tomentosa) were impregnated and modified with them. Their physical and mechanical properties were tested and compared with those of the wood treated with S of 20% mass fraction (S20). Infrared analysis showed that amino resin characteristic structure (CO-NH-) existed in MUG resin. The resin has good permeability. Compared with S20 modified wood, the degree of shrinkage of G10S20 or G20S10 modified wood is reduced, their moisture absorption is reduced, and their dimensional stability is improved. Waterborne glucose silicone modifier can effectively improve the wood density, modulus of elasticity, modulus of rapture and compression strength. SEM analysis showed that the cell wall of G20S10 modified wood was significantly thicker than the untreated wood, and there were columnar and granular solid substances attached in some cell cavities, ducts and corners, etc. EDX showed that the number of Si elements on the cell wall was significantly increased compared with the control, indicating that the modifier effectively entered the wood cell wall. The waterborne glucose silicone resin can greatly improve the physical and mechanical properties of wood through organic-inorganic hybridization. It is a green, non-formaldehyde, eco-friendly, low cost, compound wood modifier with broad application prospects.

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Interpreting research results for the physical and mechanical properties of wood: An approach not dependent on a juvenile/mature wood boundary

BioResources ◽

10.15376/biores.16.4.6921-6932 ◽

2021 ◽

Vol 16 (4) ◽

pp. 6921-6932

Author(s):

Tomislav Sinković ◽

Branimir Jambreković ◽

Tomislav Sedlar

Keyword(s):

Mechanical Properties ◽

Radial Direction ◽

Statistical Tests ◽

Physical And Mechanical Properties ◽

Wood Properties ◽

Mature Wood ◽

Raw Material ◽

Technological Properties ◽

Wood Processing ◽

The Difference

The interpretation and presentation of research on the physical and mechanical properties of wood in the radial direction is important for the estimation of technological properties in primary wood processing. It is common practice to define the boundary between the juvenile and mature wood zone of tree growth because of the differences in wood properties in these two zones. The juvenile and mature wood zones can be determined statistically based on the significance of the difference in the properties in a particular zone. This paper presents the insufficiency in the statistical determination of the boundary between juvenile and adult wood. Such limitations detract from the potential value and technological exploitation of wood as raw material. Statistical tests yielded zones that were too wide for the transition of juvenile wood to mature wood. Representations of the distribution of properties in the radial direction also complement the knowledge for assessing the technological properties based on the researched use of the presentation of polynomials of the second degree and the display of the Tukey HSD test in the form of comparison tables. The graphical representations by groups of the tested annual rings of fir wood also help to assess the technological properties.

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Prediction of physical and mechanical properties of thermally modified wood based on color change evaluated by means of “group method of data handling” (GMDH) neural network

Holzforschung ◽

10.1515/hf-2018-0146 ◽

2019 ◽

Vol 73 (4) ◽

pp. 381-392 ◽

Cited By ~ 11

Author(s):

Vahid Nasir ◽

Sepideh Nourian ◽

Stavros Avramidis ◽

Julie Cool

Keyword(s):

Neural Network ◽

Mechanical Properties ◽

Color Change ◽

Physical And Mechanical Properties ◽

Group Method ◽

Data Handling ◽

Color Parameters ◽

Swelling Coefficient ◽

Thermally Modified Wood ◽

Modified Wood

AbstractThe effect of thermal modification (TM) on the color of western hemlock wood and its physical and mechanical properties were investigated. The focus of this study was the prediction of material properties of thermally modified wood based on the color change via the “group method of data handling (GMDH)” neural network (NN). The NN was trained by color parameters for predicting the equilibrium moisture content (EMC), density, porosity, water absorption (WA), swelling coefficient, dynamic modulus of elasticity (MOEdyn) and hardness. The color parameters showed a significant correlation with temperature and are well correlated with the heat treatment (HT) intensity. Color parameters combined with the GMDH-type NN successfully predicted the physical properties of the material. The best correlation was achieved with the swelling coefficient, EMC and WA. All these properties were significantly influenced by HT. The color parameters did not seem suitable for predicting the wood hardness and MOEdyn. The GMDH NN shows a higher model accuracy than the multivariate linear and partial least squares (PLS) regression models.

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Physical and Mechanical Properties of Poplar Wood Modified by Glucose-Urea-Melamine Resin/Sodium Silicate Compound

Forests ◽

10.3390/f12020127 ◽

2021 ◽

Vol 12 (2) ◽

pp. 127

Author(s):

Qiangqiang Liu ◽

Haojia Du ◽

Wenhua Lyu

Keyword(s):

Mechanical Properties ◽

Cell Wall ◽

Sodium Silicate ◽

Physical And Mechanical Properties ◽

Modulus Of Rupture ◽

Infrared Analysis ◽

Poplar Wood ◽

Melamine Resin ◽

Characteristic Structure ◽

Modified Wood

In order to improve the performance of soft plantation wood, an environmentally friendly wood modifier was developed. First, using urea and melamine as crosslinking agents, the glucose-urea-melamine resin (MUG) was prepared with glucose under the catalysis of inorganic acid and metal ions. Then MUG, sodium silicate, and distilled water were mixed and stirred at 40 °C to prepare MUG resin/sodium silicate compound modifier (G20S10, G10S20, the subscript number represents the mass percentage of the component in the solution.). Then plantation poplar wood (Populus tomentosa) was impregnated and modified with them. Their physical and mechanical properties were tested and compared with those of the wood treated with sodium silicate of 20% mass fraction (S20). Infrared analysis showed that the amino resin characteristic structure (CO-NH-) existed in MUG, and the absorption peak of the furan ring (C=C) appeared. Compared with S20 modified wood, the shrinkage degree of G10S20 or G20S10 modified wood is reduced, their moisture absorption is decreased, and their dimensional stability is improved. MUG resin/sodium silicate compound modifier can effectively enhance the wood’s density, modulus of elasticity, modulus of rupture, and compression strength. SEM analysis showed that there were columnar and granular solid substances attached to the cell wall, cell lumen, intercellular space, and vessel of G20S10 modified wood. EDX showed that the number of Si elements on the cell wall was significantly increased compared with the control, indicating that the modifier effectively entered the wood cell wall. The G20S10 can greatly improve the wood’s physical and mechanical properties through an organic–inorganic compound synergistic effect. It is a green, non-formaldehyde, low cost wood modifier with broad application prospects.

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