Evaluation of capillary radii in wood by the centrifugal method.

通过离心法评估木材中的毛细管半径。

基本信息

批准号：
08456089
负责人：
HAYASHI Kazuo
金额：
$ 4.1万
依托单位：
EHIME UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08456089/
关键词：
CENTRIFUGAL FORCE WATER POTENTIAL MENISCUS CAPILLARY RADIUS FLOW IN WOOD ASPIRATED BORDERED PIT PAIRS PERMEABILITY DAMAGE OF TORUS CONTACT ANGLE 通気性高周波減圧乾燥

项目摘要

1.The size distribution of free water paths for six species of softwood was estimated by centrifugal method which is a new method developed from the balance of water potential decreased by centrifugal force and capillary pressure by meniscus and the amount of dehydrated free water by centrifugal force. The distribution depends on species and the location in wood. For example, the radius in earlywood was larger than one in latewood. This result was presumed to be the feature for undried wood as there was the contrary result for dried sample.2.The change of effective radius of free water paths by local steam explosion was obtained quantitatively by the centrifugal method.3.The damage of pits by the centrifugal force was easier in sapwood than in heartwood because of the strength of adhesion between pit border and torus. Pits in Sugi damaged easier than those indouglas fir because the ratio of the diameters of torus and pit aperture is larger in douglas fir than in sugi and the torus in douglas fir was supported stronger than one in sugi.4.The force required for the damage of pits was 0.1 to 0.2 MPa for the sapwood in sugi. For the pits in heartwood larger value was estimated by centrifugal method. This means pits in wood has possibility to be damaged by capillary tension during drying.5.The contact angle of wood was considered to be zero in wet condition so far. However it was not truth. Wettability in heartwood was poor than sapwood, but after hygroscopic thermal treatment both location showed same contact angle. This tendency was same to the alcoholbenzene extractive treatment. This mean that the existence of the extracives on cell wall affects to the wettability even the wet condition.

1.通过离心方法估算了六种软木的游离水路径的尺寸分布，这是一种新方法，它是从水势的平衡来开发的，弯盘和毛细管压力降低了，弯板压力和毛细管压力通过离心力通过离心力降低。分布取决于物种和木材中的位置。例如，早期伍德的半径大于拉特伍德的半径。假定该结果是干燥样品的相反结果。2。局部蒸汽爆炸的有效自由水路路径的有效半径的变化是通过离心方法定量地获得的。3。在Sapwood在Sapwood中，离心力的损坏比在心脏材料中更容易，因为在心脏材料中，距离粘合膜之间的粘合力更容易。 SUGI中的凹坑比那些Indouglas FIR容易受损，因为在道格拉斯FIR中，圆环和坑孔的直径比Sugi中的比率更大，而道格拉斯FIR中的圆环比Sugi中的一个比sugi中的圆环更强。对于心脏木中的凹坑，通过离心方法估算了更大的值。这意味着在干燥过程中，木材中的凹坑可能会因毛细管张力而受到损害。5。到目前为止，木材的接触角被认为在潮湿状态下为零。但是不是真理。心脏的润湿性比Sapwood差，但是在吸湿热处理后，两个位置都显示出相同的接触角。这种趋势与酒精苯二苯萃取治疗相同。这意味着细胞壁上的外推存在也会影响润湿性。