Lee, Jeong Min
(Department of Wood and Paper Science, College of Agriculture & Life Sciences, Kyungpook National University)
,
Lee, Won Hee
(Department of Wood and Paper Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Kyungpook National University)
잣나무 열압밀화재의 완전한 치수안정화를 위해 열압밀화 후 열처리를 하였다. 열처리가 된 열압밀화재의 치수안정성 평가를 위해 흡수시험을 실시하였다. 0.43의 비중인 목재를 두께 압축률 50%로 열압밀화를 실시하여 0.79의 비중을 가진 고비중재를 얻었다. 열압밀화 후 열처리를 통하여 열처리 온도와 시간이 증가함에 따라 흡수성과 팽윤성이 감소하였다. 두께 회복률의 경우는 $120^{\circ}C$, $140^{\circ}C$, $160^{\circ}C$ 모두 24시간동안 열처리를 진행하였을 때, 1% 미만의 두께 회복도를 나타내었다. 따라서 열압밀화재의 치수안정화는 후 열처리 공정을 통하여 매우 효과적으로 시행할 수 있는 방법임을 확인할 수 있었다.
잣나무 열압밀화재의 완전한 치수안정화를 위해 열압밀화 후 열처리를 하였다. 열처리가 된 열압밀화재의 치수안정성 평가를 위해 흡수시험을 실시하였다. 0.43의 비중인 목재를 두께 압축률 50%로 열압밀화를 실시하여 0.79의 비중을 가진 고비중재를 얻었다. 열압밀화 후 열처리를 통하여 열처리 온도와 시간이 증가함에 따라 흡수성과 팽윤성이 감소하였다. 두께 회복률의 경우는 $120^{\circ}C$, $140^{\circ}C$, $160^{\circ}C$ 모두 24시간동안 열처리를 진행하였을 때, 1% 미만의 두께 회복도를 나타내었다. 따라서 열압밀화재의 치수안정화는 후 열처리 공정을 통하여 매우 효과적으로 시행할 수 있는 방법임을 확인할 수 있었다.
Post-heat treatment experiments were carried out for complete dimensional stabilization of thermally compressed wood (Pinus koraiensis). An absorption test was carried out to evaluate the dimensional stability. The specific gravity increased from 0.43 to 0.79 by thermal compression at a compression ...
Post-heat treatment experiments were carried out for complete dimensional stabilization of thermally compressed wood (Pinus koraiensis). An absorption test was carried out to evaluate the dimensional stability. The specific gravity increased from 0.43 to 0.79 by thermal compression at a compression ratio of 50% thickness. Through the post-heat treatment of compressed wood, the water absorption and thickness swelling decreased with increasing the heat treatment temperature and time. In the case of the thickness recovery rate, when the heat treatment was performed for 24 hours at $120^{\circ}C$, $140^{\circ}C$ and $160^{\circ}C$, the thickness recovery was less than 1%. Therefore, it can be confirmed that the method of dimensional stabilization method of the thermal compression wood can be carried out very effectively through post heat treatment process.
Post-heat treatment experiments were carried out for complete dimensional stabilization of thermally compressed wood (Pinus koraiensis). An absorption test was carried out to evaluate the dimensional stability. The specific gravity increased from 0.43 to 0.79 by thermal compression at a compression ratio of 50% thickness. Through the post-heat treatment of compressed wood, the water absorption and thickness swelling decreased with increasing the heat treatment temperature and time. In the case of the thickness recovery rate, when the heat treatment was performed for 24 hours at $120^{\circ}C$, $140^{\circ}C$ and $160^{\circ}C$, the thickness recovery was less than 1%. Therefore, it can be confirmed that the method of dimensional stabilization method of the thermal compression wood can be carried out very effectively through post heat treatment process.
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제안 방법
Five specimens were processed at 120ºC, 140ºC, and 160ºC for 2, 6, 12, and 24 hours for each condition.
The study examined the dimensional stability of thermally compressed wood of Korean pine after the post-heat treatment based on each of the thermal compression conditions and the heat treatment conditions. The wood of Korean pine of which specific gravity was 0.
The test aimed to acquire the dimensional stability by the thermal compression and air-dry process of Korean pine and examine the optimal conditions for the dimensional stabilization and reviewed the result of the test.
The three sides of all specimens were exposed to the air and placed in a desiccator, and using a load plate with holes, they were submerged about 50 mm below the water. To measure the amount of absorption and the swelling ratio based on the absorption time, the weight and thickness of the specimens were measured in every 30 minutes from the start to two hours, in every one hour from two to five hours, in every two hours from five to nine hours, and in every three hours from nine to 24 hours. Before each measurement, the specimens were wiped with dry towel to remove the moisture on the surface.
대상 데이터
However, in this study all sides were exposed to moisture to conduct the test under the same conditions as those of the previous studies. A total of 20 specimens were used for each thermal process temperature setting. The three sides of all specimens were exposed to the air and placed in a desiccator, and using a load plate with holes, they were submerged about 50 mm below the water.
This study used Korean pine (Pinus koraiensis) among Korean soft wood species. Flat-sawn Korean pine were cut in 60mm(L) × 60mm (T) × 24mm (R) to create a specimen.
이론/모형
To verify the dimensional stability of the specimen, a 24-hour absorption test was conducted based on KS F 2204. In KS F 2204, the waterproof paint is applied to the side that is not the absorption side so that moisture cannot be absorbed.
성능/효과
Furthermore, the amount of absorption after five hours when it became stabilized was lower at 160ºC than at the other temperature settings, and particularly, the specimen at 160ºC for 24 hours showed that the amount of absorption was initially 0.019 g/cm²·h and decreased to 0.006 g/cm²·h when the test completed.
, 2015) conducted the thermal compression at 180℃ for 60min of compression period at the pressure of 80kgf/cm², and later, the thermal process at 80℃, 100℃, or 120℃ was performed for 2, 6, 12, and 24 hours. The results showed that the thickness recovery ratio of the thermally compressed wood at 120℃-24h was 3.8%, and when compared with the specimen without thermal process, the thickness recovery ratio was reduced by about 67%. As such, since there is clearly the different properties by wood species, it is absurd to say that the results of a certain wood species would represent the process condition of all species.
Particularly, the thickness recovery ratio of the specimen heat-treated at 160ºC for 24 hours reached almost to 0%. Therefore, when all of the results of the aforementioned moisture absorptiveness, swelling, and dimensional stability were examined, the thermally compressed specimen at 200ºC for 90 minutes and post-heat treated at 160ºC for 24 hours showed the highest dimensional stability.
참고문헌 (16)
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