• Title/Summary/Keyword: dimensional stability

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Dimensional Stability of Plastic Processing Wood Material - Compression Wood and Bentwood -

  • Hwang, Kweon-Hwan;Lee, Won-Hee
    • Journal of the Korea Furniture Society
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    • v.18 no.2
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    • pp.143-146
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    • 2007
  • This study was carried out to assess the dimensional stability of wood material treated by plastic processing for bentwood and compression wood. The evaluation method was different between two wood materials, but the treatments for them were very similar to each other. One of the main methods is heat treatment with sufficient water vapor. In bentwood, the used species were painted maple (Acer mono), bitter wood (Picrasma quassioides) and birch (Betula schmidtii). Steaming was the worst treatment method for dimensional stabilization of bentwood. The best results could be attained with PEG treatment for dimensional stabilization of bentwood. Dimensional stability of bitter wood was found to be conspicuous. However the steaming treatment at lower temperatures, i.e., about $130^{\circ}C$ was not suitable for dimensional stability of bentwood. In compression wood, the used specimen was Italian poplar wood (Populus euramericana). Two heat compressive pressing conditions, an open-press system and an air-tighten closed-press system, were used. The recovery rate was measured after boiling and/or absorbing in water to estimate the dimensional stability of heat compressed wood. The best dimensional stability of compressed wood in the air-tighten closed-press system was found to be better at $200^{\circ}C$ than $180^{\circ}C$. The best compression rate for dimensional stability was 73 percent.

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Heating Compression of Italian Poplar (Populus euramericana) Wood - Dimensional Stability Against Moisture -

  • Jung, In-Suk;Lee, Weon-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.91-96
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    • 2002
  • This study was carried out to estimate the property of dimensional stability of heat compression of italian poplar wood with low density. Firstly, two levels of pressure conditions were applied using the closed and open-press system. The thermal treatment temperatures were 180℃ and 200℃, respectively. Water absorption tests were conducted in water bath at 25℃ and 100℃ for 35 hours and 1 hour, respectively. The compression rates of wood were 47 percent, 60 percent, and 73 percent, respectively. From these tests, it was found that the dimensional stability of the closed-press system was superior to that of the open-press system. Furthermore, the dimensional stability of compressed wood in the closed-press system was better at 200℃ than 180℃. In compression rate, dimensional stability of 73 percent compression rate was the best result. Considering these results, the best conditions for the dimensional stability of compressed wood were those of the closed-compressing system at high temperatures above 200℃ and larger compression rate. Therefore, it was concluded that the dimensional stability of wood is improved at higher temperature and larger deformation.

Dimensional Change of Acetylated Hardwood (아세틸화 활엽수재의 치수변화 특성)

  • 한규성
    • Journal of the Korea Furniture Society
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    • v.11 no.2
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    • pp.79-84
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    • 2000
  • It is well-known fact that dimensional stability of wood is greatly enhanced by acetylation of wood. This dimensional stability results from bulking of the reacted acetate within the cell wall, which reduces further swelling when the modified woods come into contact with water or water vapor. The purpose of this research was to determine the water absorption and dimensional stability of the acetylated solid wood in liquid water and in humidity tests. Beech and red oak were acetylated. Moisture and water absorption of acetylated wood were quite dependent on weight percent gain(WPG). Antiswelling efficiency(ASE) was quite dependent on WPG, but was not dependent on species.

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Effect of Heat Treatment on the Dimensional Stability and the Bending Properties of Radiata Pine Sapwood

  • Yun, Ki-Eon;Kim, Gyu-Hyeok;Kim, Jae-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.27 no.4
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    • pp.30-37
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    • 1999
  • The effects of heat treatment on the dimensional stability and bending properties of radiata pine sapwood were investigated. The dimensional stability was almost achieved by heat treatment though the loss of strength was accompanied as a negative effect. The improvement in dimensional stability of wood and the resultant reduction in bending properties were closely related to treatment temperature and duration. The optimum treatment conditions, which could be used to achieve a desired improvement in dimensional stability with resultant losses in modulus of rupture were proposed based on the results obtained in this study.

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Improvement of Paper Dimensional Stability for The Printed Electronics Base Paper (인쇄 전자 용지의 특성 구현을 위한 치수 안정성 향상에 대한 연구)

  • Kim, Byong-Hyun;Yoo, Hee-Tae;Kang, Young-Reep
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.1
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    • pp.35-44
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    • 2011
  • For printed electronic paper making which is high leveled dimensional stability. The furnish which is hard wood pulp and soft wood pulp, mixed with hard and soft wood pulp is added sea algae pulp. If sea algae pulp was added 15% contents, paper which is made with hard wood pulp is increased about 28% dimensional stability and soft wood pulp is increased about 32%, dimensional stability and hard wood 30% and soft wood 70% mixed pulp is increased about 40% dimensional stability.

Dimensional Stability of Bentwoods by Treatment Conditions

  • Jung, In-Suk;Lee, Weon-Hee;Chang, Jun-Pok;Bae, Hyun-Mi
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.85-90
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    • 2002
  • This study was carried out to investigate the dimensional stability of bentwoods by three treatments: steaming, urethane varnish coating, and polyethylene glycol (PEG) treatment. Bentwood processing employed a bending-jig with only 4 cm radius of curvature (ROC). The used species were bitter wood (Picrasma quassioides), painted maple (Acer mono), and birch (Betula schmidtiii). The bending properties of these are well-known in bentwood production (Jung et al., 2002). The bentwoods were treated repeated at room temperature [20℃, RH 80% (12 hours) and 40℃ under RH 10% (12 hours)]. To estimate the dimensional stability of bentwoods, we measured the radius of curvature and end-distance. The best results could be attained with PEG treatment. Steaming was the worst treatment. Comparing the properties of the different species, the dimensional stability of bitter wood was excellent. It was concluded that the steaming treatment was unsuitable for dimensional stability of bentwoods.

Effect of Washing Conditions on Dimensional Change and Mechanical Properties in Polyester/Spandex Knit Fabric (세탁조건에 따른 폴리에스터/스판덱스 편성물의 형태안정성과 역학적 특성 변화)

  • Roh, Eui Kyung;Kim, Eunae
    • Fashion & Textile Research Journal
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    • v.20 no.1
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    • pp.93-100
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    • 2018
  • This study comparatively analyzed the changes in the dimensional stability and the mechanical properties of stretch knit fabrics associated with washings conditions in order to determine the most appropriate washing method. Polyester and spandex knit fabrics were washed 25 cycles with nine washing condition profiles that controled detergent, hardness. temperature and RPM. The knit fabrics with repeated washings were evaluated by dimensional stability and measured by the KES-FB system. Polyester and spandex fibers have good chemical resistance. However, the changes in the dimensional stability and the mechanical properties were observed in washed knit fabrics. After repeated washings, the knit fabrics washed in an alkali or neutral detergent had good dimensional stability compared with the knit fabric washed in functional detergent. The washed knit fabrics were extended, stiff, rough, and had a smaller volume. The changes were the result of the rearrange of polyester fibers which twisted around spandex core and chemical interactions involving the detergent and the physical and mechanical forces of washing. Especially, using an alkali detergent resulted in increased stiffness and roughness of the knit fabric. In conclusion, the washing in water with low hardness and a neutral detergent can minimize the changes in dimensional stability and mechanical properties of polyester and spandex knit fabric.

Estimation of dimensional stability of woods with time by Polyethylene glycol treatment (Polyethylene glycol처리과정 중 목재 치수안정성의 경시적 평가)

  • 권구중;김남훈
    • Journal of the Korea Furniture Society
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    • v.13 no.1
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    • pp.2-8
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    • 2002
  • This study was carried out to investigate the reasonable condition for better dimensional stability in woods by polyethylene glycol(PEG) treatment. Eight species grown in Kangwon-do were used for this study. Three species of softwoods(Pinus densiflora, Pinus koraiensis, Larix kaempferi) and two species of hardwoods(Prunus sargentii, Populus tomentiglandulosa) treated with 30% aqueous solution of PEG 1000 showed good dimensional stability under the treatment for 1 day. The dimensional stability of Betula davurica, Quercus mongolica and Quercus variabilis woods increased with increasing treatment time. From the above results, it was concluded that PEG penetration and dimensional stability were affected by characteristics of wood species such as density and structure.

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A Study on Dimensional Stability and Thermal Performance of Superheated Steam Treated and Thermal Compressed Wood

  • Chung, Hyunwoo;Han, Yeonjung;Park, Jun-Ho;Chang, Yoon-Seong;Park, Yonggun;Yang, Sang-Yun;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.2
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    • pp.184-190
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    • 2016
  • Recently, wood is attracting attention as green building interior decoration material. When wood is used as building interior decoration material, excellent dimensional stability and thermal performance is required. In this study, superheated steam treatment process and thermal compression process were applied to flat sawn Pinus koraiensis wood panel in order to improve dimensional stability and thermal performance. According to results of this study, superheated steam treatment process and thermal compression process improve thermal performance and dimensional stability of wood, especially in tangential direction. The spring back in radial direction reduces the effect of thermal compression on dimensional stability of wood in radial direction.

Posttreatment Effects of Castor Bean Oil and Heating in Treated Jabon Wood on Boron Leaching, Dimensional Stability, and Decay Fungi Inhibition

  • PRIADI, Trisna;LESTARI, Marini Dwi;CAHYONO, Tekat Dwi
    • Journal of the Korean Wood Science and Technology
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    • v.49 no.6
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    • pp.602-615
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    • 2021
  • Red jabon wood is a potential fast-growing species for veneer, furniture, and many other wood products, but its durability is very low. The purpose of this study was to investigate the effects of castor bean oil and heating on boron leaching, dimensional stability, and resistance to decay fungi in treated jabon wood. Red jabon wood was preserved with boron solutions containing 5% boron (boric acid, borax, or borax-boric acid). Following that, castor bean oil impregnation and heating were used as posttreatments. Furthermore, all the wood samples were tested in terms of leaching, dimensional stability, and resistance against Schizophyllum commune and Fomitopsis palustris fungi. This study discovered that boron compounds, castor bean oil, and heating treatments influenced the leaching, dimensional stability, and resistance of red jabon wood to decay fungi. The double impregnation of boric acid or borax and castor bean oil, followed by heating at 160℃, significantly reduced water absorption and leaching while increasing the dimensional stability and resistance of red jabon wood against the two tested decay fungi.