| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation, on a plate surface, of a vascular bundle extending upward while winding in a spiral shape on an oil palm trunk, by increasing mechanical strength by using a component originally provided in an oil palm, without disposing of the oil palm trunk.SOLUTION: An oil palm material W is cut out in a predetermined dimension from the oil palm trunk WD, and is heated with heating plates N1,..., Nn from both-side surfaces of the cut-out oil palm material W, and both sides of the oil palm material W are also softened; compressive force is imparted to the oil palm material W with the heating plates N1,..., Nn under a temperature condition where a temperature at the center of the oil palm material W is lower than a temperature on both side surfaces of the oil palm material W; after supplying heat and pressure for a predetermined time, the surface temperature of the heating plates N1,..., Nn on both sides of the oil palm material W is lowered down to a predetermined temperature, and is cooled to release the pressure; and the oil palm trunk WD is displaced on at least one surface parallel to the length direction of the oil palm trunk WD of the oil palm material W so that an end part of the vascular bundle K extending in a substantially spiral shape, is not exposed from the oil palm material W. |
