JPH07291B2 - Method for manufacturing wood-based molded body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a wood-based molded product, and more particularly to a method for directly producing a compression-molded product using a wood-based molding material.

(Prior Art) Generally, for example, wood chips such as chips are defibrated by a defibrating machine to form wood fibers, and a binder such as synthetic resin is added to the wood fibers to form a molding mat as described below. Formed,
This molding mat is compression molded by thermocompression molding or the like to obtain a hard wood-based molding, and this wood-based molding is widely used as a so-called hard board as a material for construction and furniture. .

Conventionally, in order to manufacture the above-mentioned wood-based molded product, first, it is composed of wood fibers defibrated by the above-described defibrating machine, hemp, non-woven fabric, and a phenolic thermosetting synthetic resin or thermoplastic synthetic resin. Using a binder and a sufficiently agitated wood-based molding material (hereinafter referred to as material), a molding mat having a thickness of 20 to 40 mm is formed.

Next, the molding mat is cut into a size slightly larger than the shape of the wood-based molded product after completion and supplied into a compression mold, and compression molded by a method such as hot pressure molding to obtain a molded product. Was doing. At this time, when a large amount of wood fibers are contained in the material forming the molding mat, the molding mat is softened by steam or the like for preforming in order to obtain deep drawability.

(Problems to be Solved by the Invention) However, the above-described conventional method for producing a wood-based molded product has the following problems.

First, in order to facilitate the supply to the compression molding process, a molding mat was formed using a wood-based material, and the step of cutting this mat into a predetermined shape was required, so the manufacturing process was complicated. In addition to the poor performance, there is a problem in that when the mat is cut to a size slightly larger than the completed molded body, the part to be cut off is wasted and the production cost increases. In addition, a binder is required to make the material into a mat, and in order to further improve the deep drawability, long fibers such as hemp and thermoplastic resin nets, which have high raw material costs, are required as mat materials in addition to wood fibers. However, when hemp fiber is used, it is necessary to add an additional thermosetting resin component, which also causes a problem of high cost.

In addition, if the material contains a large amount of wood fibers, the mat must be softened with steam to improve the deep drawability and preformed into the shape of the molded body in advance. Due to this, the corners where the mat is extended become thin, and when this preform is supplied to the molding die and compression-molded as it is, the thinned corners have a low density and There is also a problem that the strength of the bent portion is reduced. The same problem occurs in the case of 85% wood fiber, and the same material as the material forming the mat is reinforced at the bent portion so as to apply a so-called patch, and then compression molding is performed.

The present invention has been made to solve the above-mentioned problems, and improves the workability and the production cost and the strength of the molded body by manufacturing the molded body without matting the wood-based material. The purpose is to improve.

(Means for Solving the Problems) The feature of the method for producing a wood-based molded product according to the present invention for achieving the above-mentioned object is that the wood-based molded product is prepared by adding a binder containing a synthetic resin to wood fibers and stirring the mixture. Prepare materials, first collect the materials in a container to form a low-density material aggregate with a thick portion corresponding to the deep-drawn portion, and then supply this material aggregate directly into the molding die. And then compression molded.

(Operation) In the method for manufacturing a wood-based molded body configured as described above, since the raw materials are simply collected in the container and supplied to the molding die, conventional matting is not required. In addition, since compression molding is performed from a state in which there is little fiber entanglement using a low-density material aggregate, the flow of peripheral fibers into the deep drawing part of the forming die is suppressed, and a thin part is generated in the formed product. It will be difficult. Moreover, since the material assembly has a thick portion in the portion corresponding to the deep-drawn portion, the supply of the material to the deep-drawn portion is sufficient, and the flow of the peripheral fibers into the deep-drawn portion is further suppressed. It

(Example) Hereinafter, an example of a method for manufacturing a wood-based molded product according to the present invention will be described in detail with reference to the drawings.

FIGS. 1 to 6 explain one embodiment of the present invention, and FIGS. 1 and 2 show compression molding by setting a material assembly formed of a wood-based molding material in a compression molding die. FIG. 3 is a schematic sectional view showing a process of forming the material aggregate, and FIGS. 4 to 6 are perspective views showing a manufacturing process of a wood-based material which is a raw material of a molded body. It is a figure, a schematic block diagram, and a partially notched perspective view.

First, a process of manufacturing a wood-based material as a raw material will be described with reference to FIGS. 4 to 6. Chips C such as wood chips are supplied to the hopper 2 of the defibrated fiber 1 shown in FIG. 4, and are supplied to the cooking tank 4 by the screw feeder 3 provided at the bottom of the hopper 2. The steaming tank 4 is provided with a preheater (LVP type), and steam S is supplied from the upper part of the tank 4 so that the chips C are softened so that the fiber content is easy to disperse. It is supplied to the defibration disc 6 by the screw feeder 5, and the chips C are defibrated into the wood fibers W1 by the defibration disc 6. The wood fiber W1 thus defibrated is fed by the pressure feeder 7 to the pressure feeding pipe 8
It is supplied to the dryer 10 shown in FIG. The dryer 10 includes a drying pipe 12 that meanders the hot air H supplied from the dryer 11 and the above-mentioned moist wood fiber W1.
Is supplied to the cyclone 13 via the, and the water A is evaporated and removed by the cyclone 13 to obtain dried wood fiber W2. Next, the dried wood fiber W2 is supplied from the supply port 16 of the agitator 15 as shown in FIG.
2 to 10% of water resistant agent (paraffin), adhesive (thermosetting or thermoplastic resin such as phenolic resin) etc. as a binder (binder), respectively, and rotating stirring blades
Both are uniformly mixed and agitated by 18 to obtain a wood-based molding material B1 from an outlet 19. Conventionally, this material B1 was used to manufacture a molding mat having a certain standard shape and flexibility, but in the present invention, an assembly is formed from the material B1 without forming the molding mat.

A step of forming a material aggregate subsequent to the above step will be described. First, the material B1 is supplied to the container 21 of the assembly manufacturing apparatus 20 shown in FIG. A shield plate 24 that moves up and down by a cylinder 23 is provided between the container 21 and the pressure-feeding pipe 22, and a predetermined amount of the material B1 is stored in the container.
The container opening 21a and the blocking plate opening 2
Match 4a. The material B1 supplied into the container 21 is agitated by the air sent from a compressor (not shown) outside the container 21 through the air holes 25a formed in the bottom plate 25 in a large number, and becomes a more uniform material mixture B2. Note that reference numeral 26
Is an on-off valve that controls the amount of air sent from the compressor. Next, the bottom plate 25 of the container 21 in which the material mixture B2 is floated and mixed is raised by driving the cylinder 27, and a vacuum (V / C) is applied from above the retainer 28 provided above the container 25. ). At this time, the forming member 30 for shaping, which is hung from the ceiling plate 29 having the suction holes 29a provided on the ceiling side in the holder 28, is formed of wire mesh, punching metal, or the like after the mixture B2 is completed. Since the material aggregate B3 is formed and attached in a curved shape or the like corresponding to the shape of the molded body, for example, the material assembly B3 after vacuuming can have a thick portion corresponding to the deep-drawn portion. Also,
The material aggregate B3 is formed by gathering together the mixture B2 (fibers) inside the retainer 28 simply by using a vacuum, so that the fibers inside have very little entanglement and its density is extremely small. Has become. In addition, reference numerals 31 and 3
Reference numeral 2 is a suction pipe and an opening / closing valve used for direct emptying of the cage 28, and reference numeral 33 is a cylinder for horizontally reciprocating the cage 28.

Next, a process for producing a wood-based molded body by compression-molding the material aggregate B3 formed as described above will be described.

In this embodiment, compression molding is performed by using the molding die 35 for thermocompression molding shown in FIGS. 1 and 2. First, as shown in FIG. 3, the cage 28 holding the material aggregate B3 is
By driving the cylinder 33, the lower mold of the molding die 35 shown in FIG.
Moved above 36 and in this position the valve 32 shown in FIG.
When is closed, the material assembly B3 falls and is set on the lower mold 36. At this time, a positioning member (not shown) for guiding the upper mold 37 at the time of molding is provided on the outer periphery of the lower mold 36,
The material assembly B3 is securely placed by the outer peripheral member 38 of the lower mold 36 without spilling out of the mold. When the set of the assembly B3 is completed, a heater and a temperature controller (not shown) of the molding die 35.
The lower mold 36 and the upper mold 37, which are respectively heated by the heating plates 39 and 39 heated by, are aligned by lowering the upper mold 37,
A vacuum is drawn in the molding space through the suction holes 37a, the suction space 37b, and the suction pipe 40 formed in the upper mold 37 to degas the material assembly B3, and as shown in FIG. The molded body M1 will be compression molded. Then, in the compression molding, since the compression progresses from the state of less entanglement of the fibers, the flow of the peripheral fibers into the deep-drawing forming portion is suppressed, and a thin portion is formed at the corner portion of the peripheral edge of the deep-drawing portion M2. It will not be formed. Further, in this embodiment, since the portion corresponding to the deep drawn portion M2 of the material assembly B3 is formed to be thick,
The fiber is sufficiently replenished to the deep-drawing part, and the flow of the fiber into the deep-drawing part is further suppressed. Reference numeral 41 is a valve that opens and closes the suction pipe 40 when vacuuming is performed.
Start vacuuming from a few mm before the bottom dead center of 37 to vent gas in the molding space, and when demolding, continue to upper mold
After sucking up to the top dead center of 37, the molded product M1 is released from the lower mold 36, and a transfer mechanism (not shown) is inserted between the upper and lower molds, and the valve 41 is switched to release from the upper mold 37. And can be supplied to the next step. Further, in this embodiment, since the molding material B1 contains a water resistant agent (paraffin),
Mold release after compression molding becomes easy.

(Effects of the Invention) As described in detail above, the method for manufacturing a wood-based molded product according to the present invention has the following effects.

First, the wood-based molding material is collected in a container to form a low-density material aggregate, and then this material aggregate is directly supplied into a molding die for compression molding to produce an essential molding. As a result, it is possible to omit the manufacturing and cutting process of the molding mat and the so-called patching work as in the past, and also to simplify the material transportation work, etc., and greatly improve the workability related to the manufacture of wood-based moldings. can do.

Further, as described above, it is possible to omit the cutting of the molding mat and the so-called patch application work, so that it is possible to save the raw material by eliminating the waste of the material such as the mat cut-off portion and the patch material that occurs during the cutting, Product yield can be improved.

Furthermore, since compression molding is performed using a low-density material aggregate in which the portion corresponding to the deep-drawing portion is thick, the flow of peripheral fibers into the deep-drawing portion of the molding die is significantly suppressed, and No thin portion is generated.

Further, unlike the one produced by the production method via a molding mat or a preform, the wood-based article produced by the method of the present invention does not require so-called patching,
The density (density) of fibers at the periphery of the deep-drawn part is sufficient,
A molded product having excellent strength can be obtained.

[Brief description of drawings]

FIGS. 1 to 6 are for explaining one embodiment of the method for manufacturing a wood-based molded product according to the present invention, and FIGS. 1 and 2 are material sets formed from wood-based molding materials. FIG. 3 is a schematic sectional view showing a process of forming a raw material aggregate, and FIG. 4 is a raw material of a wood-based molded body. FIG. 5 is a perspective view showing a defibrating machine for defibrating the wood fibers, FIG. 5 is a schematic configuration diagram showing the same wood fiber dryer, and FIG. 6 is a part showing a stirrer similarly stirring the wood fibers and the binder. It is a notch perspective view. 20 …… Material assembly manufacturing device, 21 …… Container, 28 …… Cage, 35 …… Compression mold, 36 …… Lower mold, 37 …… Upper mold, 38…
… Peripheral member, 39… Hot plate, B1… Wood material, B3… Material assembly, M1… Wood molding, M2… Deep drawing part.

Claims (2)

[Claims] 1. A wood-based molding material prepared by adding a binder containing a synthetic resin to a wood fiber and stirring the mixture. First, the material is collected in a container and a portion corresponding to a deep-drawn portion is made thick. A method for producing a wood-based compact, which comprises forming a low-density raw material aggregate and then directly supplying the raw material aggregate into a molding die for compression molding. 2. The method for producing a wood-based molded product according to claim 1, wherein the binder contains a water resistant agent.