US 2014/0000464 A1Published application

Dewatering Method for Correcting Water Content of Green Veneer for Plywood and Apparatus for Dewatering the Green Veneer

AssigneeTaihei Machinery Works, Ltd.

InventorsMitsumasa Narita, Yasuyuki Ohdaira

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Abstract

A large number of green veneers for plywood respectively having high water contents and formed in a rectangular shape are vertically laminated to obtain a veneer laminate having a quadrangular prismatic shape. The veneer laminate is located between upper and lower platen members so that two opposite side faces of the veneer laminate vertically form cut face gathering planes. The upper and lower platen members are moved toward each other to apply a pressing force to the veneer laminate. The pressing force applied to the veneer laminate is released or weakened while the water drawn through the cut face gathering planes by the pressing force is dripping downward along the cut face gathering planes of the veneer laminate vertically formed.

Claims6

Dependent claims

A dewatering method for correcting water contents of green veneers for plywood, wherein a large number of green veneers for plywood respectively having high water contents and formed in a rectangular shape are vertically laminated to obtain a veneer laminate having a quadrangular prismatic shape, cut faces of the green veneers for plywood, which are end faces of the green veneers for plywood intersecting with a direction of fibers, are vertically aligned, the veneer laminate is located between upper and lower platen members so as to vertically form cut face gathering planes by two opposite side faces of the veneer laminate, the upper and lower platen members are moved toward each other to apply a pressing force in the range of 15 to 50 kg/cm2 to the large number of laminated green veneers for plywood constituting the veneer laminate, and water contained in the green veneers for plywood is drawn through the cut faces of the green veneers for plywood and drips downward along the cut face gathering planes vertically formed where the cut faces of the green veneers for plywood are gathered, and

the pressing force applied to the veneer laminate is released or weakened in the range of 0 to 10 kg/cm2 while the water is dripping downward and the cut faces and fibers inside of the green veneers for plywood spread in a direction of original shape of the green veneers for plywood to generate a negative pressure, and the water dripping downward along the cut face gathering planes is suctioned into fibers of the green veneer having a relatively low water content by a suctioning action generated from the cut faces toward the inside by the negative pressure and the pressing force in the range of 15 to 50 kg/cm2 is applied again to the large number of green veneers for plywood, so that at least one cycle of these steps that ends with the application of pressing force can lessen a variability of the water contents in the veneer laminate among the green veneers for plywood and in different parts of each of the green veneers for plywood while an overall water content of the veneer laminate is reduced.

An apparatus for dewatering green veneers for plywood, wherein a large number of green veneers for plywood are vertically laminated to obtain a veneer laminate, and the veneer laminate is subject to a pressing force vertically applied to the veneer laminate to be compressed and dewatered to reduce a water content of the veneer laminate, the apparatus including:

a support platen supporting the veneer laminate;
a pressing member provided above the support platen and movable toward and away from the support platen;
a pressing cylinder adapted to drive the pressing member and push the pressing member against the veneer laminate;
a regulating member provided so as to vertically move relative to the support platen, the regulating member being adapted to stand upright from the support platen to be in contact with or closely adjacent to perpendicular walls on at least two opposite sides of the veneer laminate to regulate movement or stretch of the veneer laminate while the veneer laminate is being pressed by the pressing member, the regulating member further being adapted to abut the pressing member moving downward to move downward integral with the pressing member;
a lifting and lowering device adapted to lift and lower the regulating member to and from an upright standing position;
and
a control device adapted to control the pressing cylinder which drives the pressing member, the control device including:
a dewatering pressing stopper which controls the pressing cylinder so that the pressing force applied by the pressing member to the veneer laminate for dewatering is released or weakened in the range of 0 to 10 kg/cm2 and the application of pressing force for dewatering stops while the veneer laminate is being pressed and dewatered by the pressing member under the pressing force in the range of 15 to 50 kg/cm2;
and
a dewatering pressing restarter which controls the pressing cylinder so that the pressing force applied by the pressing member to the veneer laminate for dewatering is increased in the range of 15 to 50 kg/cm2 to restart the application of pressing force for dewatering, wherein
at least one cycle of the application of pressing force for dewatering and the stop of pressing force for dewatering is performed and ends with the application of pressing force for dewatering.

8 more elements

Dependencies are inferred from the claim text.