• Journal of the Korean Wood Science and Technology
• /
• v.24 no.1
• /
• pp.34-47
• /
• 1996

Veneers of two nominal thicknesses, 1.5 and 2.5mm, were rotary peeled from Japanese larch (Larix leptolepis). Dahurian larch (Larix gmelinei) and Radiata pine (Pinus radiata) bolts unheated and heated in the water vat temperature of $66^{\circ}C$ by rising a final temperature at 10cm core of $60^{\circ}C$ to remain core diameter of 11.4cm. 1.5 and 2.5mm thick veneer cut from the heated Japanese larch were significantly thinner than those of the unheated bolt and 2.5mm thick veneer cut from the heated Dahurian larch were significantly thicker than that of the unheated bolt. 1.5mm thick Dahurian larch veneer and 1.5 and 2.5mm thick Radiata pine veneers showed insignificant difference between the unheated and heated bolts, respectively. Check distance on the loose side of 1.5mm thick veneer cut from the heated Radiata pine was significantly wider than that of the unheated bolt. However check distances on the loose side of 1.5 and 2.5mm thick Japanese larch and Dahurian larch veneers and 2.5mm thick Radiata pine veneers showed insignificant difference between the unheated and heated bolts. Also the depth of check on the loose side of three species showed insignificantly difference between the unheated and heated bolts. Arithmatic mean deviation($R_a$) and maximum height($R_{max}$) of the profile on the loose side of dried veneer by preheating the bolt compared with unheated bolts were different among apecies and between veneer thickness. The preheating treatment slightly affected qualities of these thin veneers such as 1.5 and 2.5mm. The yield of 2.5mm thick veneer from the heated radiata pine was significantly higher than that of the unheated bolt. However the yield of 2.5mm thick veneer for other two species and 1.5mm thick veneer for three species showed insignificant difference between the unheated and heated bolts. The yield of 2.5mm thick veneer for three species were higher than those of 1.5mm thick veneer. The average yields of green veneer of Japanese larch. Dahurian larch and Radiata pine were 57.1, 55.1 and 54.0 percent, respectively. Variables such as initial MC. drying time and veneer thickness had strong effect for Japanese larch veneer, less effect for Radiata pine veneer and nuch less effect on final MC for Dahurian larch veneer in jet drying. Correlation between the current MC and the drying time of Dahurian larch with low variation of initial MC was higher than those of Japanese larch and Radiata pine veneer with high variation of initial MC in high temperature drying. Thickness shrinkages of 2.5mm thick veneer for Japanese larch and Radiata pine were higher than those of 1.5mm thick veneers, but shrinkages of Dahurian larch veneer were similar between two nominal veneer thicknesses.

• Journal of Korean Society of Forest Science
• /
• v.32 no.1
• /
• pp.64-72
• /
• 1976

A series of rooting experiments of P. radiata needle fascicles were carried out in test tubes using peat-pumice medium to see a possibility of rooting fascicles in test tubes and, if possible, to find out whether that method can improve the rooting. Typical rooting of clones from ortets aged 3, 7, 11. 18, and over 40, respectively, was 57%, 47%, 18%, 4%, and 2%. The effect of ortet ages upon rooting of fascicle cuttings was significantly exerted in these experiments. In the older ortets these results are not as good as those often obtained in a glasshouse. Hormones tested (indolebutyric acid and abscisic acid) had no significant effect on rooting and neither did a series of fungicides tested. Needle fascicles placed in an 18 hour day at $20^{\circ}/10^{\circ}C$ (day/night temperature) rooted signficantly better than those in a 10 hour day at the same temperature regime. The latter in turn rooted better than those set under a 10 hour day at $15^{\circ}/5^{\circ}C$. Clonal differences in rooting ability were also distinct in every trial of the present experiments with needle fascicles.

• Journal of the Korean Wood Science and Technology
• /
• v.36 no.5
• /
• pp.24-32
• /
• 2008

Artificial brown-rot decay was induced to two wood species, Pinus densiflora and Pinus radiata. A modified direct inoculation method was used and the decay indicators of mass loss and two compressive mechanical properties, maximum compressive strength (MCS) and compressive stiffness, were estimated over the period of 8 weeks of fungal exposure. Measurable mass loss occurred 2 weeks after the fungal attack, with 15% to 22% of the loss occurring 8 weeks after fungal exposure with Fornitopsis palustris and Gloeophyllurn trabeurn. Mechanical properties proved to be far more sensitive than mass loss detection: approximately five to six times by quantity. Of the two mechanical properties, MCS was more sensitive to and consistent with progressive brown-rot decay. An ultrasonic test was performed to determine the feasibility and accuracy of this method for nondestructive detection of brown-rot decay. The ultrasonic test is highly sensitive at qualitative detection of the early stages of brown-rot decay.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1161-1161
• /
• 2001

Rapid cost-effective methods of measuring wood quality are extremely important to tree improvement programs where it is necessary to test large numbers of trees. Non-destructive sampling of a forest can be achieved by using increment cores generally removed at breast height. At CSIRO Forestry and Forest Products methods for the rapid, non-destructive measurement of wood properties and wood chemistry based on increment core samples have been developed. In this paper the application of near infrared (NIR) spectroscopy to the prediction of a range solid wood properties, including density, longitudinal modulus of elasticity (E$\sub$L/) and microfibril angle (MFA), is described. Experiments conducted on individual species (Eucalyptus delegatensis and Pinus radiata), the two species combined and a number of mixed species from several genera are reported. NIR spectra were obtained from the radial/longitudinal face of each sample and used to develop calibrations for the measured physical properties. When the individual species were used the relationships between laboratory determined data and NIR fitted data were good in all cases. Coefficients of determination (R$^2$) ranging from 0.77 for MFA to 0.93 for stick density were obtained for E. delegatensis and R$^2$ ranging from 0.68 for MFA to 0.94 for strip density were obtained for P. radiata. The calibration statistics for the combined E. delegatensis and P. radiata samples were similar to those found for the individual species. As these results indicated that it might be possible to produce general calibrations based on samples from a number of species of a single genus or samples from a number of different genera, a wide range of species was subsequently tested. Good relationships were obtained for both density and E$\sub$L/. These calibrations had R$^2$ that were slightly lower than those determined using individual species and standard errors that were higher. The mixed species calibrations, when applied to the E. delegatensis and P. radiata sample sets, provided good estimates of density (stick and strip) and E$\sub$L/. The results demonstrated that a mixed species calibration, that encompasses wide variation in terms of, wood anatomy, chemistry and physical properties, could be used to rank trees. Experiments reported in this paper demonstrate that solid wood properties can be estimated by NIR spectroscopy. The method offers a rapid and non-destructive alternative to traditional methods of analysis and is applicable to large-scale non-destructive forest resource assessment, and to tree breeding and silvicultural programs.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.4
• /
• pp.491-498
• /
• 2014

In order to obtain basic data for concentration control of alkaline copper quat (ACQ) solution in wood preservative treatment, this study investigates the change of concentration and adsorption of treating solution and active ingredient, copper oxide (CuO) and didecyldimethyl ammonium chloride (DDAC), in the process of recycling of ACQ solution. Japanese larch (Larix leptolepis), Douglas-fir (Psedotsuga menziesii) and Radiata pine (Pinus radiata) were treated with ACQ solution. The active ingredient concentration of ACQ solution was decreased continuously with increase of recycling. There are differences between extent of concentration decrease of Cu (as CuO) and DDAC. DDAC was decreased more quickly and to a higher degree than Cu for all recycling. The extent of DDAC concentration decrease was remarkable than that of Cu for wood species. The amount of DDAC adsorbed into wood decreased with the increase of ACQ solution recycling, but adsorption of Cu was little difference regardless of recycling. The adsorption of Cu into wood increased as DDAC concentration decrease by recycling of ACQ solution. This is likely due to decrease of DDAC competition with Cu for the same reaction site in wood.

• Journal of the Korean Wood Science and Technology
• /
• v.24 no.2
• /
• pp.61-70
• /
• 1996

침엽수재(針葉樹材)(Radiata pine, Pinus radiata)MDF와 활엽수재(闊葉樹材)(Rubber wood, Hevea brasiliensis)MDF 각 1종을 대상으로 MDF를 제조하기 전 원료(原料) 섬유(纖維)의 미세(微細) 구조(構造) 및 내부결합력 시험 후 MDF의 파괴면(破壞面)에서 섬유표면(纖維表面)에 접착제(接着劑)가 도포(塗布)된 형태를 주사전자현미경(走査電子顯微鏡)으로 관찰하였다. 원료 섬유는 침(針) 활엽수재(闊葉樹材) 모두 fiber twisting 및 shrinkage fold 등이 관찰되었다. 침엽수재(針葉樹材)의 경우는 유연벽공부(有緣壁孔部)에서 유연벽공(有緣壁孔)이 없는 부분에 비하여 shrinkage fold의 발생 빈도가 낮고 표면(表面) 박리(剝離)는 가도관(假導管) 중 벽공이 없는 부분에서 관찰되었다. 활엽수재(闊葉樹材) 목섬유(木纖維)는 침엽수재(針葉樹材)와 마찬가지로 shrinkage fold가 관찰되었으나 표면(表面) 박리(剝離)는 거의 관찰되지 않았다. 활엽수(闊葉樹) 섬유(纖維)에서는 벽공의 유무에 따른 shrinkage fold의 차이(差異)가 거의 관찰되지 않았는데 이는 목섬유(木纖維)가 침엽수(針葉樹) 가도관(假導管)보다 작은 단벽공(單壁孔)을 갖기 때문으로 생각된다. 또 방사유세포(放射柔細胞)와 가도관(假導管) 및 목섬유(木纖維)의 박리(剝離) 부분(部分)에는 융기부(隆起部)가 관찰되었다. 내부결합력 시험후 나타난 파괴면을 통하여 접착제 분포를 관찰한 결과 거의 모든 섬유(纖維)들이 접착제(接着劑)로 둘러싸여 있었으며 섬유(纖維)간 접착형태(接着形態)도 매우 다양하였다. 침활엽수재(針闊葉樹材)간에 강도(强度)의 차이는 있었지만 파괴(破壞) 형태(形態)는 큰 차이를 나타내지 않았다. 즉 침활엽수(針闊葉樹) 모두 접착층(接着層)이 아닌 섬유(纖維)에서 파괴(破壞)가 발생하였으며 섬유에서 박리(剝離)된, 세포벽(細胞壁)의 일부가 다른 섬유(纖維)의 표면(表面)에 남아있는 형태와 섬유(纖維) 표면(表面)에서 떨어져 나간 형태로 관찰되었다. 세포 구성이 단순한 침엽수(針葉樹) MDF에 비하여 유세포(柔細胞)와 도관(導管) 및 목섬유(木纖維)의 파편들이 활엽수(闊葉樹) MDF에서는 다양(多樣)하게 분포하였다.

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.6 s.134
• /
• pp.87-94
• /
• 2005

This study was carried out to investigate the effect of soil types and soil properties on wood preservative leaching. Radiata pine (Pinus radiata Don.) sapwood stakes, which had been treated with 2.0%(w/v) CCA, were leached for 12 weeks by a common laboratory method in four different soils and for 14 days by the AWPA standard leaching method in water. The physical and chemical properties of the four soils were determined, and the percent leaching of the individual component of CCA was correlated with the various soil properties. The data show that leaching of preservative chemicals from treated wood exposed to soil is influenced by the type of soil. The preservative leaching was greater when wood was exposed to water than when the wood was in contact with water-saturated soil. The greatest chromium, copper and arsenic leaching from CCA-treated stakes were observed in the sandy loam, loam, and sand, respectively, and the least amount of leaching of CCA components occurred in the silty loam. The leaching of preservative components from treated wood is extremely complex and appears to be influenced differently by the soil properties. The extent of copper leaching from CCA treated wood appears to be related to exchangeable Mg and sum of bases. There is a reasonably good relationship between chromium leaching and exchangeable Mg, and between arsenic leaching and exchangeable K, soil Ni, Mn, Fe, Cr, or Cu content. Since this study was conducted based on laboratory leaching method using small cross-sectional dimensions; thus, data obtained from this experiment should not be used to predict leaching characteristics from commercial-size wood used in real situation. Accordingly, further studies are necessary using outdoor ground-contact leaching.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.3
• /
• pp.41-49
• /
• 2005

Styrofoam as shock-absorbing materials for packaging has been regarded as one of non-biodegradable products leading to soil contamination at a landfill and release of dioxine during its incineration. For avoiding severe burdens on our environments by styrofoam, it must be replaced by environment-friendly materials. In order to evaluate availability of pulp fibers as a substitute for styrofoam, various extrusion processes were applied for making optimal biodegradable products. Then thermomechanical pulp fibers made of Pinus radiata and Pinus rigida were uniformly mixed with other additives such as starch and polyvinyl alcohol prior to expansion. The physical properties of the final products were examined by measuring expansion efficiency, compression strength, and elastic modulus. Wheat starch played a key role to maintain optimal flowing conditions within the barrel of the extruder irrespective of addition of soluble starch and polyvinyl alcohol. However, as the amounts of wheat starch in raw-materials increased, the elastic modulus of the expanded materials greatly increased. High elastic modulus is not suitable as shock-absorbing products for packaging. Thus the wheat starch must be added at a minimum if possible, that is, below 20% based on oven-dried weight of pulp fibers. the elastic modulus of the expanded products was decreased as their moisture contents increased. For the products containing 20% wheat starch, the lowest elastic modulus, 844.64 kPa was obtained under 10% of the moisture content. This was similar to that of styrofoam.

• Journal of the Korean Wood Science and Technology
• /
• v.27 no.1
• /
• pp.56-63
• /
• 1999

Machinability of three Korean domestic bamboo species, Phyllostachys pubescens Mazel, Phyllostachys nigra var. henonis Stapf. and Phyllostachys bambusoides S. et Z., was studied to investigate the possibility of utilization of Korean domestic bamboo species as raw material for industry. Splitting force reached a maximum within the first inch of knife travel and diminished thereafter. Parallel-sided wedge-type knife with sharpness angle of 15 degree required the lowest maximum splitting force. Roughnesses of surfaces developed during planing and sawing of bamboo were lower than those of Pinus radiata D. Don and quality of ripped surface was better than that of cross-cut surface on bamboo. 62.5 hours were required to dry 12mm-thick Phyllostachys pubescens Mazel from moisture content of 60% to moisture content of 10% at $70^{\circ}C$.

• Journal of the Korean Wood Science and Technology
• /
• v.24 no.3
• /
• pp.57-64
• /
• 1996

제지공장에서 사용하는 습윤제는 물의 표면장력을 낮춤으로써 목재섬유가 물을 빨리 흡수하여 팽윤하도록 도와준다. 목재섬유가 물을 흡수하여 팽윤하는 과정을 밝히지 위한 연구가 많이 진행되어 왔지만 목재섬유와 물의 상호작용을 상세히 연속적으로 측정할 방법이 전에는 별로 없었다. 목재섬유가 팽윤할 때 발생하는 팽윤압력은 음향방사를 동반하기 때문에 이를 측정하여 팽윤과정을 알아내는 기술이 개발되었다. 본 연구에서는 이 방법을 이용하여 목재를 여러 농도의 습윤제에 담갔을 때 발생하는 음향방사와 중량증가를 측정하여 이 두 변량의 상관을 조사하고 이 방법이 목재의 습윤과정 연구에 유용하게 사용될 수 있는지를 조사하였다. 아까시나무와 라디에타 파인의 두 수종을 사용하였는데 두 수종의 흡수 형태는 매우 달랐다. 5분 동안 용액에 침지하였을 때 후자가 전자보다 10배 정도 더 많이 중량증가하였으며, 발생한 음향방사도 후자가 전자보다 훨씬 많았다. 아까시나무의 중량증가와 음향방사는 습윤제 농도에 거의 무관하였으나 라디에타 파인의 음향방사는 습윤제 농도의 증가에 따라 증가하였으며 라디에타 파인의 중량증가는 습윤제의 표면장력 변화와 일치하였다. 수종별 중량증가와 음향방사의 관계는 아까시나무가 음의 상관을 나타냈으나 라디에타 파인은 양의 상관을 나타내었다. 자비처리 시편은 무처리 시편보다 음향방사가 적었다.