• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.76-85
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• 2020

This study was conducted to analyze the application of boron compounds, methyl methacrylate (MMA), and heat treatment (HT) on changes in the density, moisture content, and flexural properties of samama (Anthocephalus macrophyllus) wood. Samama wood was impregnated with borax (BX) and boric acid (BA) using a pressure method at 5 atm for 4 h. Afterwards, the wood was impregnated with MMA at the same pressure and duration. Finally, the samama wood was given HT at 90 ℃ and 180 ℃. The results indicate that there was a weight gain of 93.4% in the wood impregnated using BA and MMA monomer and HT at 90 ℃. Consequently, the wood's density increased by 82.3%. Increased MOE and MOR percentages of 32.2% and 29.4%, respectively, were also found. HT at 180 ℃ degraded the wood components and MMA, and consequently, the density, MOE, and MOR also decreased. The wood impregnated by BX, BA, and MMA, and subjected to HT also had decreased moisture content (MC). This research recommends that the application of boron (BX, BA) should be combined with an MMA monomer and HT at 90 ℃ as an alternative method to improve samama wood quality. If darker color is preferable, HT should be conducted at 180 ℃.

• Journal of the Korean Wood Science and Technology
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• 제22권3호
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• pp.32-38
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• 1994

The methods in wood processing are so limited at present that a scope of its utilization is restricted. This often makes wood itself less valuable as a material comparing with other materials, that is, plastics, metals, and glass. Such differences are due to a lack of plasticity in wood, i.e. it cannot be melted, dissolved, or softened sufficiently for molding. However, once plastic properties are added to wood, it becomes more useful material. This further broadens the method in wood processing to a variety of fields. In this way, wooden material which is limited in use can be modified into a high quality product with additional value. Furthermore, utilization of wastes from wood, for example, would be made viable. In this study, thermoplasticization was carried out by benzylation of wood(sawdust). Various factors those affect the reaction were tested to produce benzylated wood with different degrees of substitution. Reaction temperature and time were the quite important factors. Optimum reaction temperature was 110$^{\circ}C$, and weight percent gains(WPG) of final products increased gradually with the increase of reaction time. The pretreatment (or preswelling) of wood with alkaline solution had a critical effect on benzylation. and the concentration of alkaline solution should be above 30% to obtain high weight percent gain. The thermal flow temperature of the benzylated wood decreased with the increase in weight percent gain, that of 80% weight percent gain is about 200$^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• 제51권5호
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• pp.410-418
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• 2023

In this study, the combustion characteristics of the Tulip tree, which is the representative broad-leaved afforestation tree in Korea, were analyzed. The flame retardant performance of the Tulip tree was analyzed by analyzing combustion characteristics on a total of three test samples; flame retardant treated, both flame retardant and oil stain-treated, and untreated. Then the flame retardance grade was classified for each of them. According to the result, test samples showed the strongest flame retardance were in order of flame retardant treated (C), both flame retardant and oil stain-treated (B), and untreated (A). As a result of analyzing the total heat emission and maximum heat emission rates, which is the evaluation standard for interior materials of Korean domestic buildings, test samples with flame retardant treat or flame retardant and oil stain treat were qualified for the flame-retardant standard. Both flame retardant and oil stain-treated samples showed higher total heat release (THR) and heat release rate compared to flame retardant-treated samples as the oil causes combustion with oxygen. On the other hand, they didn't qualify the THR in Quasi-non-combustible standards. To determine the correlation between the physical and combustion characteristics of wood, the combustion characteristics of other diffuse porous wood species, with which the Tulip tree is affiliated were analyzed, and noticed that the characteristic correlates with the density and quantity of wood. The results of this study are expected to be used as basic information on the combustion characteristics of the Tulip tree.

• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.265-273
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• 2015

In general, when wood products are used outdoors for a certain period of time the surface color of wood changes due to light, water, heat and so on. This color change can be considered importantly for the product's market value. In this study, the color change of ACQ (Alkaline Copper Quaternary) and CBHDO (CuO $H_3BO_3$ N-cyclohexyldiazenium-anion) treated wood and untreated wood was investigated during 2-year weathering test. From this experimental study, it was found that the colors of the treated wood changed more reddish and yellowish from green. Meanwhile, the untreated wood turned to grey color rapidly. Also, the color of the treated wood in short-term exposure changed closer to the inherent color of the fresh natural wood than that of the untreated woods.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.32-40
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• 2020

While the utilization of wood as a raw material in related industries has been increasing with the population increasing, the availability of wood from natural forests has continued to decline. An alternative to this situation is the manufacture of particleboard from non-wood lignocellulose materials through the modification of sandwich particleboard (SPb) using bamboo strands as reinforcement. In this study, strandsof belangke bamboo (Gigantochloa pruriens W) and tali bamboo (Gigantochloa apus) were utilized. The non-wood particles included sugar palm fibers, cornstalk, and sugarcane bagasse. The board was made in a three-layer composition of the face, back, and core in a ratio of 1: 2: 1. The binder used was 8% isocyanate resin. The sheet was pressed at a temperature of 160℃ for 5 min under a pressure of 3.0 N/㎟. Testing included physical and mechanical properties based on the JIS A 5908 (2003) standard, while acoustic testing was based on ISO 11654 (1997) standards. The results showed that using bamboo strands as reinforcement has an effect on the mechanical and physical properties of SPb. Almost all the types of boards met the JIS A 5908 (2003) standards, with the exception of thickness swelling (TS) and internal bond (IB) parameters. Based on the thickness swelling parameter, the C-type board exhibited the best properties. Overall, the B-type board thatused a belangke bamboo strand for the surface and sugarcane bagasse as the core underwent the best treatment. Based on the acoustical parameter, boards using a tali bamboo strand for the surface and sugar palm fiber as the core (E-type board) exhibited good sound absorption properties.

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.21-26
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• 2001

Acquisition of precise information on drying characteristics of wood is indispensable for the improvement of drying schedules and wood quality. Recognition of the exact moisture content at which drying defects such as checks occur during drying with given drying conditions may be essential to reduce drying losses. In this study an image-processing system was combined with a laboratory-scale wood dry kiln for experiments and the surface of tree disk of black locust (Robinia pseudoacacia L.) was monitored to investigate the behavior of check formation over all the drying process. This system showed good potential for improving drying schedules and wood product quality.

• 한국응용과학기술학회지
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• 제35권1호
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• pp.247-253
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• 2018

본 연구에서는 수입되는 바이오매스를 대체하고 증가하는 국내 RPS의무비율을 보다 효과적으로 대응하기 위해 우드펠릿으로 사용가능한 국내 산림바이오매스 부존자원을 파악하기 위하여 선행연구 방법과 매년 추가로 성장하는 임목생장률을 기준으로 미이용 산림바이오매스의 양을 산정하였다. 그 결과, 임목가공 중 발생하는 부산물 중 20%를 우드펠릿 원료로 사용한다고 가정했을 경우 두 가지 추정 방법으로 도출된 평균값을 기준으로 우드펠릿 생산 가능량을 예측 하였다. 그 결과 미이용 부산물은 2016년 199만 톤, 2020년 228만 톤, 2030년 308만 톤이 발생되고 원목가공 과정에서 발생되는 임목부산물(피죽, 톱밥 등) 중 20%가 우드펠릿 원료로 활용될 경우 2016년 258만 톤/년, 2020년 295만 톤/년 2030년 398만 톤/년의 원재료가 추가되어 미이용 부산물과 원목가공 과정 중 발생되는 부산물로 생산 가능한 우드펠릿 양은 2016년에 274만 톤/년, 2020년 314만 톤/년 2030년 423만 톤/년의 우드펠릿이 생산 가능하다는 결과를 도출 하였다.

• Journal of the Korean Wood Science and Technology
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• 제51권5호
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• pp.381-391
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• 2023

Densification is a technique used to improve biomass quality in wood pellet manufacturing and torrefaction treatment. In this study, the effects of torrefaction on the quality of Calliandra wood pellets were investigated, and pellets of Calliandra wood (Calliandra calothyrsus) and bark were evaluated. The study was conducted using a completely randomized design with two treatment factors, namely torrefaction temperature (250℃ and 300℃) and torrefaction duration (30, 45, and 60 min). The results showed that the interaction between temperature and torrefaction duration significantly affected the compressive strength, proximate value, and calorific value of the torrefied Calliandra wood pellets. An increase in the temperature and torrefaction duration decreased the compressive strength, moisture content, volatile matter content, and ash content of the torrefied Calliandra wood pellets. Conversely, the calorific value of Calliandra wood pellets increased with increasing temperature and torrefaction duration. The best-quality Calliandra wood pellets were produced at a torrefaction temperature and duration of 300℃ and 60 min, respectively. In terms of important quality parameters, ash content of 0.90% and calorific value of 6,303.80 cal/g were observed, which complied with the quality standards of Indonesian National Standard 8675:2018 and Deutsche Industrie Norm 51731.

• Journal of the Korean Wood Science and Technology
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• 제48권3호
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• pp.315-325
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• 2020

Boron compound had many advantages as wood preservative, but it was prone to leaching. Improving boron preservation was required to extend the service life of fast growing and low durability red jabon (Antochephalus macrophyllus) hardwood. This study aimed to evaluate the dimensional stability, color change and durability of modified red jabon wood by double impregnation with boron and methyl methacrylate (MMA) and heat treatment. Impregnation I used boric acid or borax, and impregnation II used MMA, while heat treatment used temperatures of 90 ℃ or 180 ℃ for 4 hours. The dimensional stability, leachability, water absorption, color change and decay resistance of modified red jabon wood were tested. The results showed that MMA impregnation increased the dimensional stability of red jabon wood, while the leaching and water absorption in the wood significantly reduced. Heating at 180 ℃ caused less water absorption and higher dimensional stability of the wood than that of heating at 90 ℃. Impregnation with boric acid and MMA followed by heating at 90 ℃ resulted in the highest wood ASE, 89.9%. The color change (∆E^*) of wood increased significantly after MMA impregnation and heating at 180 ℃. Boric acid impregnation caused more resistant wood than borax impregnation against decay fungi and termites. Impregnation with boric acid and MMA followed with heating at 180 ℃ increased significantly the wood resistance against decay fungi and termites.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.21-22
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• 2014

The purpose of this study is to ascertain strengths and hardening rate of epoxy-modified mortar with wood-tar contents. The polymer-modified mortars (PMMs) using epoxy resin with wood-tar are prepared with various polymer-binder ratios of 1, 3, 5% and wood-tar contents of 0, 5, 10, 15 and 20%. The PMMs using epoxy resin are tested for compressive, flexural and tensile strengths and hardening rate of epoxy resin. As a result, the strengths and hardening rate under polymer-binder ratio 1% and wood-tar content of 5% are more excellent than those of other specimens.