• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.65-71
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• 1991

본 연구는 CCA 처리재의 재건조(再乾燥)시 적용된 건조 스케쥴 (통상(通常) 열기건조(熱氣乾燥)와 고온건조(高溫乾燥) 스케쥴)이 처리재의 휨강도(强度) 성질에 미치는 영향을 고찰하고자 수행되었다. 탄성계수(彈性係數)(MOE), 그리고 비파괴시험(非破壞試驗)에 의해 얻어진 동적(動的) 탄성계수 (Dynamic MOE) 및 대수감쇠율(對數減衰率)(Logarithmic decrement) 은 처리후 재건조에 의해 큰 영향을 받지 않았다. 반면에 적용된 건조 스케쥴에 관계없이 재건조시 심각한 파괴계수(破壞係數)(MOR)의 감소가 파괴계수 분포의 모든 영역에서 초래되었다. 그러나 통상 열기건조(최대 건구온도=$71^{\circ}C$)와 고온건조(건구온도=$110^{\circ}C$) 서로간에는 감소의 정도에 큰 차이가 없었다. 따라서, 처리재의 재건조사 심각한 파괴계수의 감소가 용인(容認)되지 않는다면 CCA로 처리된 Lodgepole pine 각재의 재건조는 미국 연방 임산물 시험장의 Lodgepole pine의 통상 열기건조 스케쥴 (T9-C3) 보다 온화(溫和)한 조건으로 실시되어야 할 것이다.

• Journal of the Korean Wood Science and Technology
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• v.13 no.2
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• pp.3-13
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• 1985

This study was carried out to investigate the effects of presteaming on the drying rate and drying defects of 3 cm - thick Quercus acutissima. Specimens for presteaming were steamed green at $100^{\circ}C$ for 4 hours and then kiln-dried to 10 percent moisture, content with controls, using the kiln-drying schedule ($T_4-C_2$) recommended by Rasmussen. The results obtained were as follows: 1. Presteaming reduced drying time approximately 18 percent from 70 to 10 percent moisture content. 2. The effect of presteaming on surface checking was not significant. 3. Presteamed specimens showed the reduction in end checking compared with controls. 4. Percents of boards with collapse, cupping, and honeycomb of presteamed specimens were slightly lower than those of controls. 5. Dry lumber grade of presteamed specimens was better than that of controls. Percent of first grade boards of presteamed specimens was 20 percent higher than that of controls and percents of second and third grade boards of presteamed specimens were 15 and 5 percent lower than those of controls, respectively.

• Journal of the Korean Wood Science and Technology
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• v.14 no.3
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• pp.3-15
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• 1986

This study was carried out to investigate the drying rate and drying defects of Populus euramericana using the SDR (Saw-Dry-Rip) process. Flitches for SDR process were rough edged for compact kiln stacking, and then kiln-dried to 10 percent moisture content with dimensions in the same run, using the kiln-drying schedule ($T_8-F_4$) recommended by Rasmussen. The results obtained were as follows: 1. Drying rate of dimensions was slower than that of flitches. 2. Final moisture content and moisture distribution of dimensions were lower than those of flitches. 3. Average bowing, cupping, crooking, and twisting were reduced 20 percent, 25 percent, 54.9 percent, and 13.4 percent by SDR process respectively. 4. Bowing and cupping were more severe in dimensions from the area near the pith than in those from the area near the bark, and for crooking and twisting the reverse was true. 5. Surface checking of dimensions developed less than that of flitches and end checking of dimensions was similar to that of flitches. 6. Honeycomb, thickness shrinkage, and collapse of dimensions were similar to those of flitches. 7. The degree of casehardening of dimensions was higher than that of flitches.

• Journal of the Korean Wood Science and Technology
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• v.41 no.3
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• pp.234-246
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• 2013

It was found that test piece heated rapidly by 3 kW microwave for 5 minutes satisfies the targeted temperature and the percentage of moisture content, and the highest rate of weight increase is obtained in case of 120 minute immersion in the mixture of phosphates and heterocyclic compounds, from the result of such analysis as: kiln drying schedule, flame retardent by flammability test, insect resistance by termites, and permeability of combined penetrant for the wood after assigning multifunctional finish by immersing conifer structural frame, which is used for the frame work of wooden house and indoor/outdoor finishing in flame retardant and insect repellent materials mixture with the remaining heat of microwave. In addition, after a test of flame retardent treated item, it was identified that every mixture of phosphates corresponds with the standards of flame retardent, and upon investigation of moritality of 7 days after putting termites, it was showed that test piece immersed in the mixture of phosphates and heterocyclic compounds has the best characteristics, showing over 96% of high moritality. From the analysis of inward permeability of combined penetrant for the wood, it was decided that excellent performance in the flame retardent and insect resistance of the wood revealed due to full penetration of combined penetrant as it was found that combined penetrant penetrated through the whole inner cells of the wood.