JPH06254818A - Pressing apparatus for wooden board - Google Patents

Abstract

PURPOSE:To shorten hot press molding time of a wooden board mat and to suppress expansion of thickness of the hot press-molded wooden board caused by water. CONSTITUTION:A wooden board mat 4 during hot press molding is stored into a closed space formed by upper and lower surface plates 3 and 1 of a press and a frame 2 to enclose stream generated from the wooden board mat 4 in the closed space by fixing the frame 2 on the circumference of the upper surface plate 3 of a hot press or a high frequency press. The steam pressure in the enclosed space is controlled by providing a lateral hole 7 in the frame 2. A lot of holes from which compressed air is ejected are provided on the lower face of the frame 2 to eject the compressed air from the holes at the stage where it begins to apply a clamping pressure and small wooden pieces fallen down from the wooden board mat 4 during clamping are blown off thereby out of the lower surface plate 1 of the press to ensure close tightness of the frame 2 with the lower surface plate 1 of the press.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood board pressing device.

[0002]

2. Description of the Related Art A hot press is generally used as a pressing device for a wood board, and a wood board mat is sandwiched between hot press platens for thermocompression molding. In this method, heat is transferred from the hot press surface plate to the wooden board mat by heat conduction, so that it takes a long time to form a thick wooden board. In addition, the water vapor generated in the wooden board mat easily escapes to the outside of the mat, so the wooden board
Domat does not undergo steam treatment at temperatures above 100 ° C. Therefore, the compressive deformation of the thermocompressed wooden board is restored by the addition of water,
As a result, the thickness expansion coefficient of the wood board shows a large value,
This is a drawback of the wood board thermoformed by hot pressing.

A high frequency press or a steam injection press is used to shorten the hot pressing time during molding. However, in the high frequency press, steam generated in the wooden board mat escapes to the outside of the mat, as in the hot press. ,Also,
The steam injection press has the drawback that it requires a boiler capable of supplying a large amount of steam.

[0004]

SUMMARY OF THE INVENTION The problem to be solved is to shorten the thermocompression molding time of a wood board mat without requiring a large-scale device, and to perform high temperature steam treatment during the thermocompression molding. By this, thermo-formed wood
It is to reduce the thickness expansion coefficient of the cord.

[0005]

In order to solve the above-mentioned problems, a frame is attached around the upper surface plate of a hot press or a high-frequency press so that a closed space formed by the frame and the upper and lower surface plates of the press is installed. Store the wooden board mat,
It was possible to confine the steam generated from the wooden board mat during the hot pressing in the enclosed space.

Further, by providing a lateral hole in the frame,
It was made possible to control the water vapor pressure in the enclosed space during thermocompression molding. Further, a large number of holes for ejecting compressed air are provided on the lower surface of the frame, and the compressed air is ejected from the holes at the stage when the compressing pressure begins to be applied to the wooden board mat, so that the wooden board mat can be compressed. The spilled wood pieces were blown out of the lower press platen so that the adhesion between the frame and the lower press platen could be ensured.

[0007]

The wooden board mat is housed in the closed space formed by the upper and lower surface plates of the hot press or the high frequency press and the frame attached around the upper surface plate, so that the wooden board can be molded during thermocompression molding. The water vapor generated from the domat will be trapped within the enclosed space. Therefore, the water vapor pressure in the closed space rises above 1 atm, and the wood board mat is exposed to high temperature water vapor exceeding 100 ° C. As a result, the heat polymerization of the adhesive applied to the wooden board mat is promoted, and the hot pressing time is shortened. At the same time, since the compressive deformation of the wooden pieces is permanently fixed, a large thickness expansion due to water, which is a drawback of the wooden boards, is improved.

By providing a lateral hole in the frame, the steam pressure in the closed space during thermocompression molding can be controlled, so that the steam temperature can be kept constant. As a result,
The quality of the thermocompression molded wood board will be stable. Furthermore, since the steam in the closed space can be gradually drained after the completion of the thermocompression molding, it is possible to prevent puncture due to the steam pressure inside the wooden board which is likely to occur during press depressurization.

Further, a large number of holes for ejecting compressed air are provided on the lower surface of the frame, and the compressed air is ejected from the holes when the pressing force begins to be applied to the wooden board mat.
Small pieces of wood spilled from the wood board mat during pressing can be blown out of the lower platen of the press. Therefore, since the wooden pieces are not sandwiched between the frame and the lower press platen, the adhesion between the frame and the lower press platen is secured.

[0010]

[Example] A wood piece coated with an adhesive was formed into a mat and placed on a surface plate 1 under a hot press.
Then, the hot press lower surface plate 1 is raised toward the hot press upper surface plate 3 around which the frame 2 is attached. At the stage where the wooden board mat 4 starts to be pressed, compressed air is blown out from a large number of holes 5 provided in the lower surface of the frame 2, and the wooden board mat 4 is hot-pressed under lapping at the time of pressing. While blowing out the small pieces of wood spilled on the outer surface of the hot press lower surface plate 1, the hot press lower surface plate 1 is raised and the wooden board mat 4 is clamped. When the lower surface of the frame 2 and the hot press lower surface plate 1 are sufficiently adhered,
The rise of the press platen 1 under the hot press and the ejection of compressed air are stopped, and the wooden board mat 4 is directly heated and pressed. A packing material 6 such as fluorine rubber or silicone rubber is attached to the lower surface of the frame 2 to enhance the adhesion between the frame 2 and the hot press lower surface plate 1.

The steam generated from the wooden board mat 4 during the hot press molding is confined in the closed space formed by the frame 2 and the hot press upper and lower surface plates 3 and 1, and at the same time, the hot press upper and lower surface plate 3 is formed. Since it is heated from 1,
The water vapor pressure in the enclosed space exceeds 1 atm and the water vapor temperature rises above 100 ° C. When the water vapor temperature reaches a predetermined high temperature, the water vapor pressure is kept constant for a predetermined time by the pressure controller 9 connected to the pipe 8 leading to the lateral hole 7 of the frame 2. Therefore, the wood board mat 4 during thermoforming is 1
It is exposed to high temperature steam having a constant temperature exceeding 00 ° C.

As a result, the heat polymerization of the adhesive applied to the wooden board mat 4 is promoted, the time for thermocompression molding is shortened, and at the same time, the compression deformation of the small wooden pieces is permanently fixed. The large thickness expansion due to moisture, which is a drawback of wood boards, is improved. Further, since the steam temperature is constant, the thermocompression-molded wood board shows stable quality.

After a lapse of a predetermined time, the water vapor in the closed space is gradually removed to prevent puncture due to the water vapor pressure inside the wooden board. The thickness of the wood board after thermocompression molding is equal to the thickness of the frame 2 attached around the hot press upper surface plate 3. Therefore, the hot press upper surface plate 3 and the frame 2
The attachment of and is a detachable structure so that the thickness of the wood board after thermocompression molding can be changed.

[0014]

As described above, the present invention shortens the thermocompression molding time of a wooden board mat by simply attaching a frame to a conventional press machine without requiring a large-scale device, and Since the wood board mat during thermocompression molding can be subjected to high-temperature steam treatment, a large thickness expansion due to moisture, which is a drawback of the wood board, can be improved. Therefore, according to the present invention, it is possible to obtain a low-cost wooden board of excellent quality.

[Brief description of drawings]

FIG. 1 is a schematic view showing a state in which a wooden board mat is placed on a surface plate under a hot press.

FIG. 2 is a bottom view of a hot press upper surface plate.

FIG. 3 is a sectional view of a hot press upper and lower surface plate portion including an AA cross section.

[Explanation of symbols]

 1 Hot Press Lower Surface Plate 2 Frame 3 Hot Press Upper Surface Plate 4 Wood Board Mat 5 Hole 6 Packing Material 7 Side Hole 8 Pipe 9 Pressure Controller

Claims (3)

[Claims] 1. A wood board mat (4) undergoing thermocompression molding is mounted on a press platen (3, 3) by attaching a frame (2) around the press platen (3) of a hot press or a high frequency press. A wooden board which is housed in a closed space formed by 1) and the frame (2) and which allows water vapor generated from the wooden board mat (4) to be confined in the closed space.
Press machine 2. The pressing device for a wood board according to claim 1, wherein the frame (2) is provided with a lateral hole (7) so that the water vapor pressure in the closed space during thermocompression molding can be controlled. 3. A plurality of holes (5) for ejecting compressed air are provided on the lower surface of the frame (2), and the wood board mat (4) is squeezed from the holes (5) at the stage when the pressing pressure starts to be applied. Adhesion between the frame (2) and the lower press platen (1) by blowing out air and blowing out the small wood pieces spilled from the wooden board mat (4) during pressing to the outside of the lower press platen (1). A press device for a wooden board, which secures the property.