Abstract
The behavior of pit membrane was examined from the dehydration process under the centrifugal field. According to this method, an arbitrary pressure difference (water potential by the centrifuge) is obtained by the rotational speed and the distance inward the dehydration surface. The pressure differential required to close the pit aperture by the pit membrane was evaluated as the range from 0.119MPa to 0.178MPa for sapwood of Sugi. The portion treated by the pressure differential of 0.252MPa was easier to dehydrate and it was estimated that the pit membranes in sapwood were broken by the pressure differential of 0.332MPa. The SEM observation showed the breaks of the pit membrane.
The pressure differential up to 1.32MPa did not make the pit membrane in heartwood break.
The centrifugal method was possible to determine the pressure differential that produces the pit aspiration and the break of pit membrane in sapwood of softwood.
