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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Wood Science and Technology
Journal Basic Information
Journal DOI :
The Korean Society of Wood Science Technology
Editor in Chief :
Volume & Issues
Volume 22, Issue 4 - Dec 1994
Volume 22, Issue 3 - Sep 1994
Volume 22, Issue 2 - Jun 1994
Volume 22, Issue 1 - Mar 1994
Selecting the target year
The Biochemical Role of Tree Extractives
Kang, Ha-Young ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 5~11
Automation of Lumber Drying System(I) -Continuously Rising Temperature Drying of Pinus densiflora-
Lee, Hyoung-Woo ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 12~19
An electrically heated experimental lumber dry kiln was retrofitted with a computer-based control system to control kiln conditions more precisely and monitor and record several kiln variables. Flat-sawn 2.5cm-thick Pinus densiflora boards were dried in constant temperature process(65
& 50~60 %RH) and continuously rising temperature process, respectively. The average drying rate in continuously rising temperature process was 5.7 %/hr, which was above 3 times faster than that in constant temperature process. But, the average rate of case-hardening and moisture difference between shells and cores of boards dried in continuously rising temperature process were 82 % and 5.5 %, respectively, which were much larger than those of boards dried in constant temperature process.
Evaluation of Exterior Durability of Domestic Plywood for Temporary Construction
Kim, Gyu-Hyeok ; Jo, Jae-Sung ; Song, Ki-Young ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 20~27
Water repellent preservative (WRP) treated and untreated, small-sized specimens prepared from semiwater resistant, water resistant, and tegofilm-overlaid plywood were exposed to outdoor weathering for one year. Exterior durability of specimens was evaluated on the basis of changes in dynamic modulus of elasticity, degree of delamination, modulus of elasticity, modulus of rupture, and glueline shear strength. Among untreated specimens, tegofilm-overlaid plywood showed the best outdoor durability, and durability between semiwater resistant and water resistant plywood was similar. Although WRP treatment increased the durability of all types of plywoods, the effect of treatment on the increase in durability for semi water resistant plywood was not distinct. Accordingly, it can be concluded that semi water resistant plywood, which is used for temporary construction such as concrete formwork in our country, can not be inadequate for exterior use, regardless of WRP treatment. The bending strength and glueline shear strength of untreated water resistant plywood measured after weathering for one year did not exceed the minimum value specified by Korean Standard (KS), thereby the outdoor use of water resistant plywood was not desirable without WRP treatment. Exterior durability between treated water resistant plywood and untreated tegofilm-overlaid plywood was very similar. This result suggests that if an exposed plywood surface is treated with WRP regularly water resistant plywood can be used for temporary construction. This suggestion, however, needs to be investigated. In summary, semiwater resistant plywood cannot be used for temporay construction regardless of WRP treatment. Water resistant plywood can be used only with WRP treatment. Comparing the cost of tegofilm-overlaid plywood to costs of water resistant plywood and WRP treatment, however, it can be concluded that use of tegofilm-overlaid plywood for temporay constrution is strongly suggested from the point of view of both outdoor durability and costs.
Utilization of Pine Bark(I) -Chemical Compositions and Characterization of Ca-base Acid Sulfite Cooking of Pine Bark-
Mun, Sung-Phil ; Kim, Jae-Phil ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 28~33
The chemical compositions of pine bark from mechanical pulp industry were determined, and effect of Ca base acid sulfite on bark cooking was investigated under various conditions. The pine bark was composed of 39.5 % alkali extractives, 50.3 % lignin, and a small amount of carbohydrate. The contents of alkali extractives and lignin were remarkably higher than those of pine wood. The bark was composed of high content of arabinose and xylose, while the wood was composed of high content of mannose. When pine bark was cooked with 75 % free acid at 145
, the rate of cooking and delignification was improved with the increase of total acid, but it was very difficult to delignify the bark by 50 % and over under these conditions. In the presence of 60~65 % free acid and at 155~165
, initial cooking rate, delignification, and delignification selectivity were considerably increased, but condensation reaction of lignin was considerable at the end of cooking. Therefore, it was shown that pine bark was very difficult to delignify by the Ca-base acid sulfite cooking.
Utilization of Pine Bark(II) -Characterization of Mg- and Na-base Acid Sulfite Cooking-
Mun, Sung-Phil ; Kim, Jae-Phil ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 34~39
Effects of Mg-base acid sulfite and Mg- or Na-base bisulfite on pine bark cooking were examined. In the presence of 75 % free acid at 145
, the rate of cooking and delignification was improved with the increase of total acid. However, the delignification could not be achieved by 50 % or more under these cooking conditions. When cooked with 50~65 % free acid and at 155~165
, the rate of cooking and delignification was remarkably improved. Thus, the bark was delignified up to 73 % when cooked for 2 hours in the presence of 50 % free acid and 24 % total acid. Na-base bisulfite was slightly more effective than Mg-base bisulfite for cooking, giving 76 % delignification of pine bark. However, there was no significant difference in selectivity of delignification between Na- and Mg-base bisulfite cooking.
A New Record of Perforated Ray Cells in Platanus orientalis L.
Eom, Young-Geun ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 40~43
Effects of Paper Sludge Addition on Formaldehyde Emission, and Physical and Mechanical Properties of UF-Particleboard
Kim, Dae-Jun ; Lee, Phil-Woo ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 44~53
This research was carried out to investigate the effect of paper sludge addition on formaldehyde emission, and physical and mechanical properties of UF-particleboard. In order to investigate the effect of paper sludge addition to resin, particleboards were bonded with urea-formaldehyde resins containing 5, 10, 15% paper sludge powders of three types(A Type: -200 mesh, B Type: -100~+200 mesh. C Type: -50~+100 mesh), based on weight of resin solid. Also the effect of paper sludge addition to furnish was studied from particleboards fabricated with ratios of sludge to particle of 5:95, 10:90, 15:85 based on oven-dry weight. Tests were conducted on the manufactured particleboards to determine formaldehyde emission, bending properties, internal bond strength and thickness swelling. The obtained results were summarized as follows: The addition of paper sludge powder to resin yielded a higher pH of cured resin. Formaldehyde emission decreased with the increase of paper sludge powder addition to resin and paper sludge composition ratio to furnish. Particleboard bonded with urea-formaldehyde resin containing paper sludge powder and particleboard mixed with paper sludge have similar bending properties(MOR, MOE) and thickness swelling compared with control particleboard. Internal bond strength of particleboards treated with paper sludge were lower than that of control particleboard. The use of paper sludge as scavenger was achieved reduction of formaldehyde emission without depression of physical and mechanical properties of particleboard. Also the use of paper sludge was able to concluded that there is possibility of partial substitution of wood particle materials.
Fire Retardancy and Mechanical Properties of Paper Sludge-Wood Particle Mixed Board
Son, Jung-Il ; Lee, Phil-Woo ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 54~65
This research carried out to investigate the effects of inorganic materials in paper sludge on the thermal degradation and of paper sludge addition on physical and mechanical properties of paper sludge-wood particle mixed boards in comparison with unmodified particleboards. Also these unmodified particleboards and paper sludge-wood particle mixed boards were soaked in aqueous solutions of fire-retardant chemicals(diammonium phosphate and zinc chloride), and their fire retardancy were tested by oxygen index method and ISO ignition test to determine the feasibility of paper sludge, industrial waste, as a recyclable resource in fabrication of fire-resisting panels for building material. Since the redrying of fire-retardant treated particleboards and paper sludge-wood particle mixed boards were made by press drying method, this process was a simple and effective method. On the other hand, flexural bending strength and internal bonding strength were also analysed to evaluate mechanical properties through standard method.
Shrinkages of Prefrozen or Presteamed Wood
Kang, Ho-Yang ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 66~71
To increase drying rate and reduce drying degradation, pretreatments such as prefreezing and presteaming have been widely used in wood industries. Presteaming lumbers prior to kiln drying is known positively to improve its permeability, to increase diffusion coefficient and to reduce discoloration, but negatively to increase collapse. Prefreezing lumbers prior to kiln drying is also known to reduce significantly its drying defects and its shrinkages. Thus it is no doubt that the pretreated lumbers shrink diversely from the untreated. In this study the shrinkage behaviors of the pretreated specimens are investigated by drying two tropical hardwoods (Apitong and Taun) in three different dying conditions: high temperature and slow drying rate (drying in a closed cylinder), high temperature and rapid drying rate (drying in an oven) and low temperature and slow drying rate(drying at room temperature). The prefrozen specimens show the least volumetric shrinkages in most drying conditions. The specimens dried in cylinders shrink most among all drying conditions. In general the pretreated specimens reached the 30 % moisture content faster than the untreated by about 30 %.
Terpenoid Analysis of the Normal, Damaged Needle and Pinecone in Pinus densiflora
Choi, Choo-I-Boo ; Hwang, Byung-Ho ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 72~79
To analyze terpene components, the essentail oil were extracted with steam distillation method from normal needle, damaged needle and pinecone of Pinus densiflora. The extracted essential oil was analyzed by gas chromatography and gas chromatography-mass spectroscopy. The results were summarized as follows; 1. Normal needles involve 43 kinds of terpene components, but damaged needles contained only 29 kinds. The most abundant components of normal and damaged needles were respectable
-pinene and caryophyllene oxide.
-pinene content in normal meedles amounted to 15.99 percents and caryophyllene oxide in damaged was 8.15 percents. 2. Pinecone showed 23 kinds of terpene components and among them the most abundant component was
-phellandrene, of which content showed 19.31 percents. 3. In normal needles, excluding
-pinene, the contents of 8 kinds of other monoterpenes, reached to 48 percents of the total terpenes, 4. In damaged needles, excluding
-pinene, the contents of 4 kinds of other monoterpenes, reached to 11 percents of the total terpenes. 5. In pinecone, excluding camphene, the contents of 6 kinds of other monoterpenes, reached to 58 percents of the total terpenes.
Studies on Printability of Amphoteric Latex-Based Coated Paper(I) - Orientation of Benzene Ring in the Latex Film -
Lee, Yong-Kyu ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 80~84
The orientation of bezene ring in latex film was investigated with raman spectroscopy. The benzene ring of anionic latex ran parallel with the film surface of latex, whereas that of amphoteric latex did not. Consequently, it showed the possibility of interactions or interrelations between the orientation of benzene ring and ink, contact angle, printability and so on.
Interfacial and Flow Properties of Latices for Paper Coating
Lee, Yong-Kyu ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 85~90
The flow properties of binder latices for paper coating were investigated, together with dynamic viscoelastic properties of latex films and electron micrographs of latices, under various conditions. The amphoteric latex, binder pigment latex and anionic latex were used in this work. The amphoteric latex has both anionic and cationic functional group on its surface. The binder-pigment with a core-shell structure has dual functions : plastic pigment and binder. The low shear viscosity of binder latices and clay slurry were measured with Brookfield vis cometer. At low-shear rates. the viscosity decreased with increasing particle size of latex. On the amphoteric latex surface, the carboxyl groups are assumed to be fully dissociated over the region of pH 9~12, but the density of negative groups seems to be increased because of the gradual decrease in the degree of dissociation of amino groups. Since the apparent particle size of latex increases with surface charge, the electroviscous effect can be observed. On the anionic latex surface, the charge density is assumed to be nearly constant above pH 8. However, below pH 8 the coagulation of particles could be observed probably because of the decrease in the charge density.
Characteristics of Super Absorbent Polymer and State of the Art
Park, Sang-Bum ;
Journal of the Korean Wood Science and Technology, volume 22, issue 1, 1994, Pages 91~112