JP3399394B2 - Method for producing fiberboard and method for producing long fiber composite board - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiberboard using long fibers obtained from kenaf as a raw material, and a method for producing a long fiber composite board using particles and long fibers obtained from kenaf as raw materials. is there.

[0002]

2. Description of the Related Art Conventionally, plywood, particle board, M
DF (medium fiberboard) is used in a wide range of fields such as building materials such as flooring materials, wall materials, and ceiling materials, door members, structural members such as skirting boards and margins, and furniture materials.

[0003] These wood-based boards are formed into a plate shape by bonding a single plate, a small piece of wood (particles) and a wood fiber, which are mainly obtained by processing a softwood or a hardwood. Therefore, it has characteristics such as stable quality, little anisotropy, and excellent workability as compared with a sawn plate obtained by sawing raw wood.

On the other hand, due to global environmental problems in recent years, the regulation of deforestation is beginning to be strengthened for the purpose of protecting forests. Instead of the conventional wood board made of softwood or hardwood, a board using non-wood resources is used. The demand for is increasing.

In response to such demands, development of boards using non-wood resources is in progress, and non-wood lignos such as bagasse, chollian, oil palm (oil palm), jute, and bamboo are used as board raw materials. Cellulose resources are starting to gain attention.

Regarding boards using non-wood resources, kenaf filaments up to about 200 mm in length obtained from the bast of kenaf (annual herbaceous mallow) are used as a raw material, and the filaments are unidirectional or orthogonal. The invention has been made with respect to directional oriented fiberboard. The present inventors have already found that a board having improved strength and dimensional stability can be realized by using kenaf long fibers as a raw material, as compared with a conventional wood board, and Japanese Patent Application No. Hei 10 (1998) has already been applied. -240596 has been filed.

Further, a method and an apparatus for producing a long fiber orientation material in producing the fiber board (Japanese Patent Application No. 10-2).
No. 95090), a lightweight long-fiber composite board composed of kenaf long fibers and a particle obtained from a kenaf core, and a method for manufacturing those boards have already been invented, and are lightweight, high strength, and have high dimensional stability. It has been found by the inventors that a sex board is feasible.

However, even with respect to a board made of kenaf filament having excellent characteristics as described above, further improvement in performance and cost reduction are demanded, and improvement of board manufacturing method. Was desired.

The manufacturing method already found by the inventors is as follows.

First, the harvested diameter is about 2 to 6 cm and the height is 2
By soaking kenaf of about 4 m in water, the kenaf is separated into a bast portion and a core portion and used as a kenaf raw material. Next, the width obtained from the bast is 1-2 cm, the thickness is several mm, and the length is 2.
After kenaf bast fiber bundles (long fiber bundles) of about 4 m are cut in the length direction, the cut long fiber bundles are randomly supplied to a defibration device such as an opener to perform a defibration process. Here, even if the kenaf bast fiber bundle (long fiber bundle) having a length of about 2 to 4 m is supplied to the defibrating device and defibrated without being cut in the length direction, the long fiber bundle is in a random state. The kenaf bast fiber bundle (long fiber bundle) cannot be defibrated unless it is cut in the longitudinal direction because it cannot be defibrated sufficiently to be supplied to the defibrator. It was difficult. In other words, even if you try to defibrate, the length of each fiber is uneven, so it takes time to process. Therefore, in order to defibrate properly, it is necessary to cut the kenaf bast fiber bundle (long fiber bundle) in the length direction. was there. The opener has a mechanism in which a cylinder with a pin rotates at high speed, and the kenaf fiber bundle is loosened by the defibration process, and the length is several tens of mm to 20 mm.
A kenaf filament having a diameter of about 0 mm and a diameter of 0.05 mm to 0.6 mm is obtained.

Next, the kenaf filaments in which the adhesive is dispersed are matted in a random state to form a filament mat, or the kenaf filaments are applied to an orienting device so that the fiber direction is unidirectional. To form a long fiber mat aligned with each other. After that, the long fiber mat alone or laminated with particles obtained by processing the kenaf core is subjected to thermocompression molding to form a plate, thereby obtaining a board that is lightweight and has high strength and high dimensional stability. It is a manufacturing method.

However, the above-mentioned manufacturing method has the following problems in order to further improve the performance and reduce the cost by simplifying the manufacturing process.

1. As a measure for improving the performance of a board made of long fibers, there is a method of using longer fibers as a board material. However, in the conventional manufacturing method, it is difficult to use long fibers of 200 mm or more, and in order to uniformly disperse the adhesive between the fibers, the fiber length is previously defibrated to about several tens of mm to 200 mm. The process to do was necessary.

2. When manufacturing a board in which long fibers are oriented, a special fiber orientation process is necessary to align a plurality of long fibers in a random state after defibration in one direction or in an orthogonal direction.

3. In the conventional manufacturing method, the shape of the long fiber mat is maintained only by the entanglement of the long fibers constituting the long fiber mat.
Therefore, it is difficult for a long fiber mat formed of kenaf fibers up to a length of about 200 mm to maintain its shape, and it is difficult to form a continuous mat. That is, there is a problem in handleability of the mat, and it is difficult to handle continuous production.

To solve the above problems 1 and 3, in order to improve the performance of the board and handleability of the mat, 2
It was necessary to develop a technology to make kenaf filaments of 00 mm or more usable as a board raw material. In addition, the above 1, 2
With respect to the above problem, there has been a demand for a new manufacturing method that greatly simplifies the conventional defibration step, adhesive dispersion step, or fiber orientation step.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is a fiber board obtained by thermocompressing kenaf filaments into a plate shape, and the kenaf filaments and kenaf parts. Regarding the long fiber composite board obtained by thermo-compressing into a plate after compounding the clou, the board performance is improved, and the defibration process, adhesive dispersion process, fiber orientation process, etc. are greatly simplified. It is an object of the present invention to provide a method for producing a fiber board and a long fiber composite board, which enhances the handling of the long fiber mat in the matting process and enables continuous production.

[0018]

In order to solve the above-mentioned problems, the method for producing a fiber board according to the present invention is obtained by thermocompressing a large number of kenaf filaments 1 in which an adhesive 12 is dispersed. In the manufacturing method of the fiber board 2, the long fiber bundles 3 obtained from the kenaf bast are arranged so that the long fiber bundles 3 are substantially parallel to each other while applying tension in the direction of the long fiber bundles 3 so as not to disturb the fiber orientation. The kenaf having the kenaf oriented in the same direction obtained in the defibration step after the defibration step, in which a large number of kenaf filaments 1 are separated so as to be oriented in substantially the same direction A step of dispersing the adhesive 12 in the aggregate 9 of the long fibers 1, and a matting step of forming the kenaf long fiber mat 4 by stacking the aggregate 9 of the kenaf long fibers 1 in which the adhesive 12 is dispersed. , Formed long fiber mat Out those characterized by comprising the the step of hot press molding. By adopting such a method, it is possible to defibrate the long fiber bundle 3 having a length of 2 to 4 m obtained from the kenaf bast portion without cutting, and to lengthen the kenaf long fiber 1 Can form the aggregate 9 oriented in substantially the same direction at the same time as the defibration, and since the kenaf long fiber 1 having a long length is defibrated in the state of being oriented in the same direction, it is subsequently adhered. This makes it possible to disperse the agent 12 uniformly, and since the long kenaf filaments 1 are entangled in a state of being oriented in the same direction, the holding power of the mat is increased and the handleability is improved. Will get better. Further, since the long fiber bundle 3 can be defibrated without being cut and can be defibrated into the kenaf long fibers 1 having a long length, the fiber board 2 has a strong mat shape holding force and improved strength characteristics. It will be possible.

Further, in the method for producing a long fiber composite board of the present invention, a large number of kenaf long fibers 1 in which the adhesive 12 is dispersed is used.
In a method for producing a long fiber composite board obtained by combining a plurality of layers made of kenaf particles 5 in which the adhesive 12 is dispersed and thermocompressing , a length obtained from the kenaf bast portion is obtained. Fiber bundle 3
Align the fiber bundles 3 so that they are substantially parallel to each other in the direction of the long fiber bundle 3
Do not disturb the fiber orientation while applying tension
The kenaf filaments 1 are almost the same by
The defibration process in which the fibers are separated so that they face each other, and this defibration process
Next, the kenaf length obtained in the defibration process and oriented in the same direction.
A step of dispersing the adhesive 12 in the aggregate 9 of the fibers 1,
The aggregate 9 of the kenaf filaments 1 in which the binder 12 is dispersed is
The kenaf filament mat 4 is formed by stacking
A matting step, a step of forming a composite mat 7 by laminating a plurality of mats 6 made of the kenaf particles 5 and the kenaf filament mat 4 after the matting step, and the composite mat 7; It is characterized by comprising a step of hot-pressing. By adopting such a method, a long-fiber composite board 5 which is lightweight but has high strength in which a layer made of long kenaf filaments 1 and a layer made of kenaf particles 5 are laminated. In addition, in forming the kenaf filament mats 4, the filament bundles 3 having a length of 2 to 4 m obtained from the kenaf bast are not cut as they are in the same manner as described above. It is possible to defibrate the length, and to form the aggregate 9 in which the long kenaf filaments 1 are oriented in substantially the same direction at the same time as the defibration, and the kenaf filaments 1 having the long length are oriented in the same direction. Since it is defibrated in the state of being orientated, it is possible to disperse the adhesive 12 evenly after that, and the kenaf long fibers 1 having a long length are entangled in the state of being orientated in the same direction. Because there is a mat Increased holding force, the better the handling properties, also,
A kenaf long fiber mat 4 is formed which can be defibrated without cutting the long fiber bundles 3 and can be defibrated into long kenaf long fibers 1, which has a strong mat shape retention force and improved strength characteristics. It is possible.

Further, the method for producing a long fiber composite board of the present invention uses a large number of kenaf long fibers 1 in which the adhesive 12 is dispersed.
And a large number of kenaf particles 5 in which an adhesive 12 is dispersed, and then, a method for producing a long fiber composite board obtained by thermocompressing a composite of the kenaf particles 5 and the kenaf long fibers 1. , Kenaf bast
The long fiber bundles 3 obtained from the
Do not apply tension in 3 directions of long fiber bundles
The fibrillation can be done by defibrating the fiber without disturbing the fiber orientation.
Separate several kenaf filaments 1 so that they are oriented in almost the same direction
The defibration process to be performed and the defibration process that follows this defibration process
To the aggregate 9 of kenaf filaments 1 oriented in the same direction
The step of dispersing the adhesive 12 and the step of dispersing the adhesive 12
By stacking the aggregate 9 of the kenaf filaments 1
The matting process for forming the kenaf long fiber mat 4,
The step of forming a composite mat 8 by dispersing the kenaf particles 5 in the voids of the kenaf filament mat 4 and the step of thermocompressing the composite mat 8 after the matting step May be By adopting such a method, it is possible to obtain the long fiber composite board 5 having the strength characteristics of the long kenaf long fibers 1 and the effect of reducing the weight of the kenaf particles 5. , Kenaf long fiber mat 4
In forming the, without cutting the long fiber bundle 3 having a length of 2 to 4 m obtained from the kenaf bast portion in the same manner as described above,
It is possible to defibrate the fiber as it is, and to form the aggregate 9 in which the long kenaf filaments 1 are oriented in substantially the same direction at the same time as the defibration.
Since the fibers are defibrated in the same direction, it is possible to disperse the adhesive 12 evenly after that, and the long kenaf filaments 1 are oriented in the same direction. Since it is entangled with each other, the holding power of the mat is increased, the handleability is improved, and it is possible to defibrate without cutting the long fiber bundle 3 to kenaf long fibers 1 having a long length, It is possible to form the kenaf long fiber mat 4 which has a strong force for holding the mat shape and also has improved strength characteristics.

In the matting step of forming the long fiber mat 4, it is also preferable to stack a plurality of kenaf long fiber mats 4 so that their fiber directions are orthogonal to each other.
By doing so, the strength in the two directions in which the kenaf filament 1 is oriented can be increased, the anisotropy of the strength can be reduced, and the dimensional stability can also be improved in the two directions. It is possible to suppress the dimensional change and reduce the anisotropy of the dimensional change.

Further, kenaf filament 2 having an adhesive dispersed therein
It is also preferable to entangle the kenaf long fibers 2 with each other by forming the long fiber mat 4 composed of the above-mentioned aggregate and then subjecting the long fiber mat 4 to needle punching. This makes it possible to reduce the anisotropy of strength and dimensional change due to the entanglement of the kenaf filaments 1.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in the accompanying drawings.

The kenaf long fiber bundle 3 obtained from the kenaf bast portion used in the present invention is as shown in FIG. Figure 1
As shown in, the kenaf long fiber bundle 3 has a width of 10 to 20.
mm, thickness 1-5 mm, total length 2000-4
It reaches up to 000 mm. These kenaf long fiber bundles 3 are fine kenaf long fibers 1 having a diameter of about 0.05 to 0.6 mm.
Are formed into a bundle.

The manufacturing method of the fiber board 2 in the present invention has a step of first defibrating the kenaf long fiber bundle 3 by using the defibrating device 10 as shown in FIG. The defibrating device 10 of FIG. 2 includes a transfer mechanism that transfers the kenaf long fiber bundle 3 as a raw material while applying tension, such as a tension applying transfer roller 10a that transfers the kenaf long fiber bundle 3 while applying tension in the direction of the arrow in FIG. Pointed pin 1
The cylinder with a pin 10b in which a large number of 0c are installed is equipped with a mechanism that rotates at high speed. The tension applying transfer roller 10a is arranged in front of and behind the pin cylinder 10b, and transfers the supplied kenaf long fiber bundles 3 while pressing the front and rear tension applying transfer rollers 10a before and after the pin cylinder 10b, respectively. The kenaf long fiber bundle 3 can be transferred while being tensioned between the front and rear tension applying transfer rollers 10a.

Width 10 to 20 mm, thickness 1 to 5 m
The kenaf long fiber bundles 3 having a length of about m and a total length of about 2000 to 4000 mm are arranged so that the long fiber bundles 3 are arranged substantially parallel to each other as shown in FIG. As shown by the arrow in FIG.
Cylinder with a pin 10b that rotates at a high speed by feeding the long fiber bundle 3 that is fed to the long fiber bundle 3 in the direction of the long fiber bundle 3 by feeding the long fiber bundle 3 in the defibrating device 10 by a transfer mechanism such as a tensioning transfer roller 10a. Thus, the kenaf filaments 1 having a fiber diameter of 0.6 mm or less are separated by separating them in the width direction without disturbing the orientation of the fibers so that the kenaf long fibers 1 are oriented in substantially the same direction. As described above, in the present invention, the long fiber bundles 3 obtained from the kenaf bast in the defibrating step are arranged so that the long fiber bundles 3 are substantially parallel to each other while applying tension in the direction of the long fiber bundles 3. By disintegrating so as not to disturb the orientation, a large number of kenaf filaments 1 having a fiber diameter of 0.6 mm or less are separated so as to be oriented in substantially the same direction.
The kenaf filamentary fiber bundle 3 having a size of about 00 to 4000 mm can be defibrated by the defibrating device 10 as it is without cutting in the longitudinal direction, and the length of the defibrated kenaf filaments 1 is 200.
Since it can be defibrated so that the kenaf long fibers 1 are oriented in substantially the same direction at the same time as the defibration process in the defibration process, the conventional orientation process for orienting the fiber direction by the orienting device is omitted. It is possible.

Regarding the defibration method, the long fiber bundles 3 obtained from the kenaf bast are arranged so that the long fiber bundles 3 are substantially parallel, and tension is applied in the direction of the long fiber bundles 3 without disturbing the fiber orientation. The above method is not particularly limited as long as it can be defibrated in this way, and for example, the long fiber bundle 3 may be passed through the cylinder portion a plurality of times while applying tension. Alternatively, for the purpose of weakening the binding force of each kenaf long fiber 1, pretreatment such as preliminarily immersing the kenaf fiber bundle 3 in water to remove the adhesive component in the kenaf long fiber bundle 3 is possible. is there.

Diameter of kenaf filament 3 after defibration (fiber diameter)
Is preferably 0.6 mm or less. Fiber diameter is 0.
If it is larger than 6 mm, the fiber bundle may not be sufficiently defibrated, and the adhesive strength between the fibers may decrease inside the fiber board.

The fiber length is preferably 200 mm or more, more preferably 600 mm or more. When the fiber length is 200 mm or more, the handleability during the matting step is good, and the effect of improving the performance of the fiber board is large.

In the production method of the present invention, the length of the kenaf filament 1 after defibration can be set appropriately by changing the operating conditions of the apparatus in the defibration step. The fiber length can be controlled within a range of approximately 200 mm to 2000 mm, although it is also affected by the length of the kenaf long fiber bundle 3 of the bast which is a raw material.

In the next step of dispersing the adhesive 12, the adhesive dispersing device 11 shown in FIGS. 3 and 4, for example, is used. The adhesive dispersion device 11 has a mechanism (not shown) for transferring the aggregate 9 of a large number of kenaf filaments 1 obtained in the defibration process by means of a belt or a roller, and an adhesive 12 for spraying the aggregate. Alternatively, it has a mechanism for spraying. FIG. 3 shows an example in which the adhesive dispersion device 11 is constituted by the adhesive 12 spray device 11a, and FIG. 4 shows an example in which the adhesive dispersion device 11 is constituted by the adhesive spray device 11b. Then, in the defibration step shown in FIG. 2 which is a step before this step, as described above, the kenaf filament bundle 3 is sufficiently defibrated and separated into a large number of kenaf filaments 1 having a long length. Since they are oriented in almost the same direction, the adhesive dispersion device 11 is used while transferring the aggregate 9 of the kenaf filaments 1 in the same direction as the orientation direction of the kenaf filaments 1 as shown in FIGS. By dispersing the adhesive agent 12, it is possible to uniformly disperse the adhesive agent 12 in the void portion of the aggregate 9 of a large number of kenaf filaments 1 or on the surface of the kenaf filaments 1.

An outline of the aggregate 9 of the kenaf filaments 1 after the adhesive is dispersed is shown in FIG.

The adhesive 12 used in the present invention may be in the form of liquid or powder.
4, the adhesive 12 is sprayed, and in the case of a powder, the adhesive 12 is sprayed as shown in FIG.

The type of the adhesive 12 used in the present invention is not particularly limited, but generally, urea resin, melamine resin, phenol resin, resorcinol resin, urethane resin, furfural resin, A thermosetting resin that heat-cures, such as an isocyanate resin, can be used.

In the next matting step, the aggregates 9 of the kenaf filaments 1 in which the adhesive 12 is dispersed are laminated so that the fiber directions of the kenaf filaments 1 are approximately one direction. The kenaf filament mat 4 as shown in FIG.

After that, if necessary, the kenaf filament mats 4 are pre-pressed (prepressed), and then subjected to a thermocompression molding step to be molded into a plate shape, so that the fiber board 2 made of the kenaf filaments 1 is formed. Is obtained. An example of the fiber board 2 obtained by the present invention is shown in FIG. In FIGS. 6 and 7, the arrows indicate the orientation directions of the fibers.

In the matting step of the present invention, the adhesive 1
The method for forming the kenaf filament mats 4 by laminating the aggregates 9 of the kenaf filaments 1 in which 2 is dispersed is not particularly limited, but the following method may be mentioned, for example.

A method of cutting the aggregate 9 of the kenaf filaments 1 in the length direction (fiber direction) and stacking a plurality of the obtained aggregates 9 of a constant length.

The kenaf long fiber bundle 3 in the bast portion of the kenaf, which is the raw material, is allowed to pass through the defibration and dispersion process of the adhesive without interruption, and then the kenaf length is adjusted by using an apparatus as shown in FIG. A method of laminating aggregates 9 of fibers 1 to continuously form a kenaf filament mat 4. In FIG. 8, an aggregate 9 of kenaf filaments 1 is fed by a cross layer 13 while reciprocating in a direction B which is a direction orthogonal to the transport direction of the kenaf filament mat 4 (direction of arrow A in FIG. 8). The aggregate 9 of the kenaf filaments 1 thus supplied is transferred to form the kenaf filament mat 4.

In the defibrating step of the present invention, the aggregate 9 of the kenaf long fibers 1 obtained by defibrating the kenaf long fiber bundle 3 has its fiber directions aligned and the kenaf long fibers 1
Are in an oriented state.

Therefore, the kenaf filament mat 4 can be easily formed while maintaining the orientation state of the kenaf filaments 1 by using any of the above methods in the matting step.

In the matting process of the present invention, the length 2
Since the kenaf filament mats 4 are formed from the aggregate 9 of the kenaf filaments 1 having a length of 00 mm or more, the kenaf filaments 1 are strongly entangled with each other and the function of retaining the mat shape is enhanced. That is, the handleability of the obtained kenaf long fiber mat 4 is improved, and since the kenaf long fiber mat 4 can be continuously formed, it is possible to cope with continuous production.

As a pressing method of the kenaf long fiber mat 4 in the thermocompression molding process of the present invention, a batch type flat plate press or a continuous press can be adopted.
There is no particular limitation. Further, the temperature, time, and pressure during the thermocompression molding are appropriately set depending on the type of adhesive, the thickness and density of the fiberboard, and the like.

The manufacturing method of the fiber board 2 in the present invention comprises the following steps as described above.

(1) The long fiber bundles 3 obtained from the kenaf bast are arranged so that the long fiber bundles 3 are substantially parallel, and tension is applied in the direction of the long fiber bundles 3 so that the orientation of the fibers is not disturbed. A defibration step in which a large number of kenaf filaments 1 are separated by defibration so that they are oriented in substantially the same direction (2) An adhesive dispersion step in an aggregate 9 of kenaf filaments 1 (3) A kenaf filament mat 4 Step (4) of forming a kenaf long fiber mat 4 is a thermocompression molding step of molding the kenaf long fiber mat 4 into a plate shape. However, in the present invention, it is possible to manufacture a fiber board using kenaf long fibers of 200 mm or more as a raw material. In addition, by having an adhesive dispersion step of dispersing the adhesive in the aggregate 9 of the kenaf filaments 1 disentangled so that a large number of kenaf filaments 1 having a fiber length of 200 mm or more are oriented in substantially the same direction, By spraying or spraying the agent, it is possible to easily and evenly disperse the adhesive. As a result, the adhesiveness is enhanced by the uniform dispersion of the adhesive, and longer fibers can be used as a fiberboard material, so that the fiberboard 2 with improved strength or dimensional stability can be manufactured. is there.

In addition to the performance of the fiber board 2, many advantages can be obtained in terms of manufacturing process.

For example, the defibration process or the adhesive dispersion process can be simplified. The kenaf filament mat 4 can be easily formed while maintaining the orientation state of the kenaf filament 1.
No special fiber orientation process is required. The kenaf filament mat 4 has a stronger function of retaining the mat shape.
The handling property is improved and the kenaf long fiber mat 4 can be continuously formed.

That is, the manufacturing process can be greatly simplified as compared with the conventional manufacturing method, and continuous production can be supported, so that the cost can be reduced. Therefore, the production method of the fiber board 2 according to the present invention enables further improvement in performance and cost reduction.

Next, a method of manufacturing the long fiber composite board will be described.

That is, the method for producing the long fiber composite board 15 of the present invention has a step of matting the kenaf particles 5 in which an adhesive is dispersed, in addition to the step of forming the long fiber mat described above. The method includes a step of forming a composite mat 7 by laminating a plurality of mats 6 made of curls 5 and the kenaf long fiber mat 4 and laminating them, and a step of thermocompressing the composite mat 7.

An example of the manufacturing method of the present invention is shown in FIG.

FIG. 9 is obtained by crushing the kenaf core 4 and the above-mentioned kenaf long fiber mat 4 obtained through the steps of defibrating, dispersing the adhesive and forming a mat as described above. A method for producing a long fiber composite board 15 having a three-layer structure in which an adhesive 12 is dispersed in a kenaf particle 5 and then a kenaf particle mat 6 obtained by subjecting the kenaf particle 5 to a matting step is laminated is shown. There is. By this method, it is possible to manufacture the long fiber composite board 15 in which the particle layer 15b made of the kenaf particles 5 and the fiber layer 15a made of the kenaf long fibers 1 are laminated as shown in FIG.

The method for forming the composite mat 7 by laminating the kenaf filament mat 4 and the kenaf particle mat 6 is not particularly limited. For example, as shown in FIG. 9, a method of stacking a kenaf particle mat 6 on a kenaf filament mat 4 which has been cut into a predetermined size in advance and then stacking the kenaf filament mat 4 again on the kenaf particle mat 6 is used. Can be mentioned.

Generally, the performance of the long fiber composite board 15 having the structure shown in FIG. 10 is greatly affected by the breaking strength or dimensional stability of the fiber layer 15a, but it is obtained by the manufacturing method of the present invention. The long fiber composite board 15
The long fiber mat 4 formed by the defibrating step of separating the kenaf long fiber bundle 3 into a large number of kenaf long fibers 1, the adhesive dispersing step in the aggregate 9 of the kenaf long fibers 1, and the matting step is used as the fiber layer 15a. Since a longer fiber, that is, a kenaf long fiber mat 4 composed of kenaf long fibers 1 of 200 mm or more can be used as the fiber layer 15a, it is possible to manufacture a long fiber composite board 15 with improved strength or dimensional stability. It will be.

In the kenaf filament mat 4, the kenaf filaments 1 having a size of 200 mm or more are entangled with each other, and the entanglement of the kenaf filaments 1 is strengthened. The composite mat 7 can be easily formed by the method shown in FIG.

Furthermore, the defibration process or the adhesive dispersion process can be simplified, and a special fiber orientation process is not required. Therefore, the manufacturing process can be greatly simplified as compared with the conventional manufacturing method, and the higher manufacturing process can be achieved. The performance and cost can be reduced.

FIG. 11 shows another embodiment showing a method for manufacturing the long fiber composite board 15. That is, FIG.
Is a continuous kenaf filament mat 4 and a kenaf particle 5 in which the adhesive 12 is dispersed is continuously supplied to continuously stack the kenaf particle mats 6 and further continuously. The long fiber composite board 15 having a three-layer structure by continuously supplying the kenaf long fiber mat 4 onto the kenaf particle mat 6 laminated by
An example of continuously manufacturing is shown.

By the manufacturing method of the present invention, a composite mat in which the kenaf filament mat 4 and the kenaf particle mat 6 are laminated can be continuously formed, and the obtained composite mat 7 is subjected to thermocompression molding. It is possible to manufacture a board having the three-layer structure shown.

The method of forming the continuous kenaf filament mat 1 is not particularly limited. For example, in FIG.
Using a device as shown in FIG. 3, the defibrating device 10, the adhesive dispersing device 11 (the defibrating by the defibrating device 10, the adhesive dispersing device 11 The adhesive 12 is dispersed as described above, and thus the description thereof is omitted.) To obtain the kenaf filament mat 4 in which fibers are oriented parallel to the direction in which the mat is continuous. . Alternatively, by using the apparatus shown in FIG. 8, it is possible to obtain the kenaf long fiber mat 4 in which the fibers are oriented in the direction orthogonal to the mat continuous direction.

The continuous kenaf filament mat 4 thus obtained can be wound into a roll as shown in FIG.

Therefore, when forming the composite mat 7,
The advantage is that the handling of the mat is excellent.

FIG. 13 shows a method of manufacturing the long fiber composite board 15 having a five-layer structure by the same method, and FIG. 14 shows a board structure obtained by this method. In FIG. 14, the arrow indicates the orientation direction of the fiber.

The manufacturing method shown in FIG. 13 is characterized in that it can be combined with an existing particle board line. Usually, a particle board production line made of small pieces of wood has a step of forming a three-layer particle mat having a surface layer and an inner layer, as shown in FIG.

Therefore, the continuous kenaf filament mat 4
By using the, it is possible to form the composite mat 7 with a small capital investment, and it is possible to significantly reduce the manufacturing process cost.

In the manufacturing method shown in FIGS. 11 and 13 in the present invention, the continuous filament mat 4 composed of kenaf filaments 1 having a length of 200 mm or more can be used as the fiber layer, so that the strength or dimensional stability is improved. The long fiber composite board 15 can be manufactured.

Further, the manufacturing process can be greatly simplified as compared with the conventional manufacturing method, such as the need for a special fiber orientation process which can simplify the defibration process or the adhesive dispersion process, and to the continuous production. By being able to respond,
The cost can be reduced, and therefore, the method of manufacturing the long fiber composite board 15 according to the present invention can further improve the performance and reduce the cost.

Next, another example of the method for manufacturing the long fiber composite board will be described.

That is, in the method of manufacturing the long fiber composite board 15 in this example, in addition to the step of forming the long fiber mat, the kenaf particles 5 in which the adhesive 12 is dispersed are added to the voids of the long fiber mat 4. It has a step of forming a composite mat 8 by dispersing the composite mat 8 in a portion and a step of thermocompressing the composite mat 8.

FIG. 15 shows an example of the manufacturing method in this example.

In the manufacturing method shown in FIG. 15, the kenaf parties in which the adhesive is dispersed in the kenaf long fiber mat 4 obtained through the steps of defibrating, dispersing the adhesive and matting as described above. The kenaf particles 5 are applied to the voids of the kenaf filament mat 4 by spraying the knuff particles 5.
And the step of forming the composite mat 8 by thermocompression molding. By this method, the long fiber composite board 15 as shown in FIG. 16 can be manufactured.

The method for forming the composite mat 8 by dispersing the kenaf particles 5 in the voids of the kenaf filament mat 4 is not particularly limited to the above method. In addition to the above, for example, the kenaf particles 5 shown in FIG. 15 are dispersed on the upper surface of the kenaf long fiber mat 4 for the purpose of uniformly dispersing the kenaf particles 5 in the voids of the kenaf long fiber mat 4, and then the composite A method of applying vibration to the mat 8 may be used.

The long fiber composite board 15 obtained by the production method of the present invention has a composite structure in which the kenaf particles 5 are dispersed inside the voids of a large number of kenaf long fibers 1 of 200 mm or more. The kenaf filaments 1 in the composite board 8 increase the board strength and reduce the dimensional change of the board. As a result, the long fiber composite board 15 having excellent strength characteristics or dimensional stability can be manufactured.

Furthermore, the manufacturing process of the kenaf long fiber mat 4 can be simplified, and continuous production can be supported, so that the cost can be reduced. Therefore, the high-performance long fiber composite board 15 can be realized at low cost by the method for manufacturing the long fiber composite board 15 according to the present invention.

The weight ratio of the kenaf filaments 1 to the kenaf particles 5 constituting the filament composite board 15 described above is not particularly limited, but the weight ratio of the kenaf filaments 1 is 5 to 50%. Preferably, more preferably 10
Within the range of 30%.

The amount of the adhesive added to the kenaf filaments 1 or the kenaf particles 5 is not particularly limited, but is preferably 2 to 30% by weight, more preferably 8 to
It is 15% by weight.

The method of dispersing the adhesive 12 on the kenaf particles 5 in the present invention is not particularly limited, but the method shown in FIG. 17 may be used. In FIG. 17, reference numeral 17 is a stirring device having a stirring blade 18 inside, and is adapted to supply kenaf particles 5 from an inlet 19 at one end.
The adhesive 12 is supplied from the spray section 21 at the tip of the adhesive supply section 20 provided near 9 and the supplied kenaf particles 5 and the adhesive 12 are conveyed while being mixed and stirred by the stirring blade 18, and the outlet 22 is provided. The adhesive 12 is dispersed in the kenaf particles 5 by being discharged from the.

As another embodiment of the present invention, in the step of forming the kenaf continuous fiber mat 4 described above, a plurality of kenaf continuous fiber mats 4 are laminated so that the fiber directions thereof are orthogonal to each other. A kenaf long fiber mat 4 (that is, an orthogonally oriented mat) oriented in two directions orthogonal to each other is formed, and then the orthogonally oriented mat alone is thermocompression-molded to produce a fiber board 2, or The long fiber composite board 15 may be manufactured by thermocompressing the composite mat 7 including the kenaf long fiber mat 4 (that is, the orthogonal alignment mat) and the kenaf particle mat 6 that are oriented in two directions orthogonal to each other. It is a thing.

There is no particular limitation on the method for forming the orthogonally oriented mat in the manufacturing method of the present invention.

For example, there is a method in which the kenaf long fiber mat 4 in which the fiber direction is oriented in one direction is cut into a predetermined size, and the cut kenaf long fiber mats 4 are stacked so that the fiber directions thereof are orthogonal to each other. .

Alternatively, the kenaf filament mats 4 oriented in one direction are laminated at right angles by the method shown in FIG. 20, whereby the kenaf filament mats 4 oriented in two directions in which the fiber directions are orthogonal, that is, kenaf The orthogonally oriented mat of the long fibers 1 can be continuously formed. In FIG. 20, an assembly 9 of kenaf filaments 1 oriented in one direction 9
Is transferred in the direction of arrow A, and another aggregate 9 of kenaf filaments 1 oriented in one direction is transferred in the direction A by the cross layer 13 in the transport direction of the aggregate 9 of kenaf filaments 1. The kenaf long fiber mat 4 having the fiber directions oriented in the two directions orthogonal to each other is laminated and formed by supplying and overlapping while reciprocating in the direction B which is a direction orthogonal to the above.

18 and 19 show examples of the long fiber composite board 15 and the fiber board 2 obtained by the manufacturing method of the present invention.

FIG. 18 is obtained by thermocompressing a three-layer composite mat 7 in which kenaf filament mats 4 oriented in two directions in which the fiber directions are orthogonal and kenaf particle mats 6 are laminated. The long fiber composite board 15 is shown. Further, FIG. 19 shows a fiber board 2 obtained by thermocompressing a kenaf filament mat 4 oriented in two directions in which the fiber directions are orthogonal to each other. The arrows in FIGS. 18 and 19 indicate the orientation directions of the fibers.

Long fiber composite board 15 obtained by thermoforming after forming these orthogonally oriented mats
Since the fiber board 2 can utilize the kenaf filament mat 4 composed of kenaf filaments 1 having a length of 200 mm or more as the fiber layer, the strength in the two directions in which the kenaf filament 1 is oriented is enhanced and the strength anisotropy is small. Become. Similarly, with respect to dimensional stability, dimensional changes in the oriented two directions are suppressed, and anisotropy of dimensional changes is reduced.

In the production method of the present invention, since the kenaf filament mat 4 oriented in two directions in which the fiber directions are orthogonal to each other can be used as the fiber layer, the strength or dimensional stability in the two directions orthogonal to each other can be improved, and The fiber board 2 and the long fiber composite board 15 with reduced anisotropy can be manufactured.

Furthermore, the defibration process or the adhesive dispersion process can be simplified, and a special fiber orientation process is not required. Thus, the manufacturing process can be greatly simplified as compared with the conventional manufacturing method, and continuous production can be realized. By making it possible to cope with the above, the cost can be reduced, and thus the production method of the present invention can further improve the performance and reduce the cost.

As another embodiment of the present invention, the entanglement of the kenaf filaments 1 is strengthened by subjecting the filament mat 4 to needle punching in the step of forming the kenaf filament mat 4 described above. A fiberboard comprising a step of forming a long fiber mat 4 and then thermocompressing the long fiber mat 4 alone or a step of thermocompressing a composite mat composed of the long fiber mat 4 and the kenaf particle mat 5. 2 and long fiber composite board 15
The manufacturing method of is mentioned.

As a method for forming the kenaf filament mat 4 in which the kenaf filaments 1 are entangled with each other in the production method of the present invention, for example, the kenaf filament mat 4 oriented in one direction is prepared by the method shown in FIG. 22 is subjected to a needle punching process with a needle 23.
It is possible to continuously form the kenaf continuous fiber mat 4 in which the entanglement of the kenaf continuous fibers 1 is strengthened as shown in FIG.

Then, the kenaf long fiber mat 4 is subjected to thermocompression molding to obtain a fiber board 2 as shown in FIG. FIG. 23 shows a fiberboard 2 obtained by thermocompressing a kenaf filament mat 1 in which kenaf filaments 1 are intertwined.

Further, by thermocompressing the composite mat 7 composed of the kenaf filament mats 4 and the kenaf particle mats 6 in which the kenaf filaments 1 are entangled with each other,
It is possible to obtain a long fiber composite board 15 in which the kenaf long fibers 1 are intertwined in the fiber layer.

These fiber board 2 and long fiber composite board 15
In the above, the entanglement between the kenaf filaments 1 is strengthened, so that the characteristics of the kenaf filament material can be further utilized. As a result, the anisotropy of strength and dimensional stability is reduced, and the strength is increased. A fiber board and a long fiber composite board having a function of increasing and an effect of suppressing dimensional change, and therefore having a small anisotropy of strength, a very high strength, and an excellent dimensional stability in the in-plane direction Is obtained.

In the production method of the present invention, a continuous long-fiber mat made of kenaf long fibers of 200 mm or more can be used as a fiber layer, and further, a step of forming a mat in which the long fibers are entangled with each other has a strength Alternatively, it is possible to manufacture fiberboards and long fiber composite boards with improved dimensional stability and reduced anisotropy, and further, the defibration process or the adhesive dispersion process can be simplified. Since the manufacturing process can be greatly simplified compared to the conventional manufacturing method, such as eliminating the need for various fiber orientation steps, and it is possible to support continuous production, cost can be reduced. According to the manufacturing method of the invention,
Higher performance and lower cost have become possible.

[0092]

Example 1 A long fiber bundle obtained from a kenaf bast (width 1 to 2 cm, thickness several mm, length 2 to 4 m)
2 was supplied to a defibration device having a mechanism in which a pin-equipped cylinder as shown in FIG. Without cutting the long fiber bundles obtained from the kenaf bast, the long fiber bundles are aligned and supplied to the defibrating device so that the long fiber bundles are substantially parallel, and the tension of the fibers is applied in the defibrating device in the long fiber bundle direction. By disintegrating without disturbing the orientation, many kenaf filaments were separated so that they would face in the same direction). The kenaf filaments disentangled after the defibration treatment have a length of about 0.2 to 2 m and a diameter of about 50 to 600 μ.
As a result, an aggregate of kenaf long fibers having a fiber length of m was obtained.

Next, an adhesive was uniformly sprayed on the aggregate of kenaf filaments oriented in the same direction obtained in the defibration step using a spraying device as shown in FIG. 3, and shown in FIG. A fiber assembly in which the adhesive as described above was dispersed was obtained. A phenolic adhesive was used as the adhesive, and the amount of dispersion was adjusted so that the adhesive solid content was 10 wt% with respect to the weight of the fiber.

Next, the aggregate of kenaf filaments in which the adhesive was dispersed was superposed in a mold of 300 × 900 mm,
A kenaf long fiber mat arranged in one direction as shown in FIG. 6 was formed. The kenaf filament mat obtained had a size of 300 × 900 mm and a surface weight of 0.24 g / cm ^2.
Met.

Finally, the kenaf filament mat was taken out of the mold and placed between the hot plates, and then a distance bar having a thickness of 4 mm was placed around the kenaf filament mat and subjected to thermocompression molding to form a kenaf fiber board. Got The conditions for thermocompression molding are a press temperature of 150 ° C. and a press pressure of 50 kgf / cm.
^2. Press time was 5 minutes.

The obtained fiber board (board) is shown in FIG. 7, and the size was 4 mm in thickness, 300 × 900 mm, and the specific gravity of the board was 0.60.

(Example 2) An aggregate of kenaf filaments disintegrated in the same manner as in Example 1 was used, as shown in FIG.
The powdery adhesive was uniformly dispersed using an adhesive dispersion device. As the adhesive, 10 wt% of a phenol powder adhesive was dispersed with respect to the weight of the fiber.

The obtained kenaf filament aggregates were laminated in the mold so that the fiber directions thereof were orthogonal to each other to form an orthogonal orientation mat. The orthogonal orientation mat has a size of 300 × 900 mm and a surface weight of 0.24 g / cm ² . The obtained orthogonally oriented mat (kenaf long fiber mat)
Was subjected to thermocompression molding in the same manner as in Example 1 to form a fiber board.

The fiberboard obtained has the structure shown in FIG. 19, and the size is 4 mm, 300 × 900 mm,
Board specific gravity became 0.61.

(Example 3) A kenaf filament aggregate obtained by defibrating treatment and dispersing an adhesive in the same manner as in Example 1 was prepared.
After stacking a plurality of sheets so that the surface weight becomes 0.24 g / cm ² , needle punching treatment as shown in FIG. 21 is performed to obtain a kenaf long fiber mat as shown in FIG. 22 in which long fibers are entangled with each other. Formed. The kenaf long fiber mat was subjected to thermocompression molding in the same manner as in Example 1 to obtain a fiber board.

The obtained board structure is as shown in FIG. 23, and the size is 4 mm, 300 × 900 m.
m, and the board specific gravity became 0.60.

(Example 4) As in Example 1, the kenaf filament aggregates, which had been defibrated and dispersed with an adhesive, were put into an apparatus as shown in FIG. Unidirectionally oriented kenaf mats were formed. By cutting the obtained kenaf filament mat, size 300 × 900 mm, surface weight 0.045 g /
kenaf length fiber orientation mat of cm ² was obtained (fiber is kenaf long fiber mat oriented in one direction).

Next, the kenaf core portion having a specific gravity of 0.15 was crushed using a ring flaker device, and an average thickness of 0.5 mm,
A kenaf particle having an average size of 4 × 8 mm was formed. A urea melamine-based adhesive was applied to the obtained kenaf particles in a solid content of 8 wt% based on the weight of the particles.

As a method of dispersing the adhesive, a stirring blender was used.

When forming the composite mat in which the fiber layer and the particle layer were laminated, the method shown in FIG. 9 was used. First, after the kenaf long fiber orientation mat is placed in the mold, the kenaf particles in which the adhesive is dispersed have an area weight of 0.
It was sprayed at 36 g / cm ² , and a kenaf long fiber oriented mat was further placed thereon to form a composite mat having a three-layer laminated structure.

Next, this composite mat was taken out of the mold, placed between hot plates, and then a distance bar having a thickness of 9 mm was installed around the mat and thermocompression molding was carried out to obtain a kenaf long fiber composite board. Obtained. The hot-pressing conditions were a press temperature of 150 ° C., a press pressure of 50 kgf / cm ² and a press time of 10 minutes.

The obtained board had the structure shown in FIG. 10, and the size was 9 mm in thickness, 300 × 900 mm, and the specific gravity of the board was 0.51.

(Example 5) A kenaf long fiber oriented mat obtained in the same manner as in Example 4 and a mat composed of kenaf particles were combined to form a composite mat by the following method, and then hot pressing was performed. By molding, a kenaf long fiber composite board was obtained. The method of dispersing the adhesive in the kenaf filament and the kenaf particle, the kind of the adhesive, and the amount of dispersion are the same as in Example 4.

The method of forming the composite mat is as follows.

A kenaf particle in which an adhesive was dispersed was placed in the mold frame of 300 × 900 mm with a surface weight of 0.045 g.
/ Cm ² and sprinkle it with a surface weight of 0.04
A kenaf long fiber orientation mat of 5 g / cm ² was installed. A kenaf particle was further sprayed on the kenaf long-fiber oriented mat so that the surface weight was 0.27 g / cm ² . After that, a kenaf long fiber oriented mat having a surface weight of 0.045 g / cm ² was installed, and further, a kenaf particle was sprayed so that the surface weight became 0.045 g / cm ² to form a 5-layer laminated composite mat. did.

Next, this composite mat was taken out of the mold, placed between hot plates, and then a distance bar having a thickness of 9 mm was placed around the mat, and thermocompression molding was carried out to obtain a kenaf long fiber composite board. Obtained. The hot-pressing conditions were a press temperature of 150 ° C., a press pressure of 50 kgf / cm ² and a press time of 10 minutes.

The obtained board has the structure shown in FIG. 14, and the size is 9 mm in thickness, 300 × 900 mm,
Board specific gravity became 0.49.

(Embodiment 6) By the method shown in FIG.
The long fiber bundle of the raw material bast portion was passed through the disentanglement and dispersion process of the adhesive without interruption to form a continuous long fiber mat in which the fibers were oriented. The method of dispersing the adhesive in the kenaf filaments, the kind of the adhesive, and the amount of dispersion were the same as in Example 1, and the width of the kenaf filament mat was about 3.
It was set to 00 mm.

The continuous kenaf filament mats are shown in FIG.
Using the method shown in 3, a kenaf long fiber composite board was obtained by incorporating it into a particle board line at a laboratory level to form a 5-layer composite mat and then thermocompressing it.

The surface weights of the kenaf filament mats and particle mats and the thermocompression molding conditions were the same as in Example 4.

The board obtained is shown in FIG.
The size was 9 mm thick, 300 × 900 mm, and the board specific gravity was 0.52.

Example 7 In the same manner as in Example 1, the kenaf filament aggregates subjected to the defibration treatment and the adhesive dispersion were put into an apparatus as shown in FIG. A directionally oriented kenaf filament mat was formed.

Next, the kenaf continuous fiber mat was formed into a kenaf continuous fiber mat whose fiber directions were orthogonal to each other by using an apparatus as shown in FIG. The obtained kenaf filament mat had a size of 300 × 900 mm and a surface weight of 0.045 g / cm ² , and the kenaf filaments in two directions orthogonal to each other had substantially the same weight.

Finally, the kenaf continuous fiber mat was combined with a mat composed of kenaf particles to form a composite mat having a three-layer structure, and thermocompression molding was performed to obtain a kenaf continuous fiber composite board.

The method of dispersing the adhesive in the kenaf filaments and the kenaf particles, the kind of the adhesive, the amount of the dispersion, and the thermocompression molding conditions are the same as in Example 4.

The board thus obtained is shown in FIG. 18. The size was 9 mm in thickness, 300 × 900 mm, and the specific gravity of the board was 0.50.

Example 8 A kenaf was prepared by forming a composite mat and thermocompressing it in the same manner as in Example 5 except that a kenaf long fiber mat formed by needle punching was used as the long fiber mat. A long fiber composite board was obtained.

The weight of the kenaf filaments and kenaf particles, the method of dispersing the adhesive, the type of the adhesive, and the amount of the dispersion during the formation of the composite mat are the same as in Example 5.

The needle punched kenaf filament mat used in this example is formed in the same manner as in Example 3 except that the surface weight is changed. The kenaf long fiber mat has long fibers entwined with each other and has a size of 300 × 900 mm and a surface weight of 0.045 g /
cm ² .

The obtained board had a thickness of 9 mm and a size of 3.
It has a size of 00 × 900 mm and a board specific gravity of 0.51.

(Embodiment 9) As in Embodiment 1, 300
Surface weight of 0.18 g / cm in a 900 mm mold ²No ke
A naphtho filament mat was formed. Next, as in Example 4,
The kenaf particles obtained by
Surface weight of 0.27 g / cm²Sprinkle so that
It was

Thereafter, while holding the mat made of particles and long fibers in the mold with plywood of 300 × 900 mm size, vibration was applied for 10 minutes to uniformly disperse the kenaf particles in the voids of the kenaf long fiber mat. Formed a composite mat. The obtained composite mat was subjected to thermocompression molding in the same manner as in Example 4 to obtain a kenaf long fiber composite board.

The obtained board has the structure shown in FIG. 16, and the size is 9 mm in thickness and 300 × 900 m.
m and board specific gravity became 0.50.

(Comparative Example 1) A long fiber bundle (width 1 to 2 cm, thickness several mm, length 2 to 4 m) obtained from a kenaf bast was cut into a plurality of pieces in the lengthwise direction, and the pieces were cut. The bundle of long fibers was supplied to a defibration device called an opener in a state where the orientation of the bundle was random, and defibration processing was performed by the defibration device. The average length of kenaf filament after defibration is about 60 mm
Is.

Next, an adhesive was dispersed in the obtained kenaf filaments using an air circulation pipe blender. A phenol-based adhesive was used as the adhesive, and was dispersed in a solid content of 10 wt% with respect to the fiber weight.

Next, the kenaf filaments coated with the adhesive were
A unidirectionally oriented kenaf long fiber mat was formed by applying the long fiber orientation device shown in JP-A-10-295090.

The fiber orienting device means that long fibers coated with an adhesive are sequentially passed through a pair of rollers in a stretching section so that the fibers are stretched to align their directions and are transferred between belts in a twisting section. Is a device for forming a mat-like shape oriented in one direction by reciprocally moving a pair of upper and lower belts in opposite directions in a direction orthogonal to the transfer direction.

The obtained fiber oriented mat was thermocompression-molded in the same manner as in Example 1 to obtain a kenaf fiber board.

The obtained fiber board had the structure shown in FIG. 7, and the size was 4 mm, the thickness was 300 × 900 mm, and the board specific gravity was 0.60.

Comparative Example 2 A kenaf filament mat obtained in the same manner as in Comparative Example 1 and a mat made of kenaf particles were combined to form a composite mat having a five-layer laminated structure, and then, as in Example 5. In the same manner, hot pressing was performed to obtain a kenaf long fiber composite board.

The structure of the composite mat is the same as that of the fifth embodiment.

The obtained board has the structure shown in FIG. 14, and the size is 9 mm in thickness, 300 × 900 mm, and the board top weight is 0.51.

(Comparative Example 3) A long fiber bundle obtained from the kenaf bast was manually defibrated to obtain a kenaf long fiber having a fiber diameter of about 2 mm and a length of about 0.2 to 2 m.

An adhesive was dispersed in the obtained kenaf filaments in the same manner as in Example 1, and then a filament mat was formed in the mold. Using the obtained kenaf filament mat, thermoforming was carried out in the same manner as in Example 1 to obtain a fiber board.

The obtained board is shown in FIG. 7, and the size is 4 mm, the thickness is 300 × 900 mm, and the specific gravity of the board is 0.
It became 61.

Table 1 shows the mat molding methods used in Examples 1 to 9 and Comparative Examples 1 and 2.

Also, the physical properties of the obtained board were measured according to JIS A
5906 (medium fiberboard) and JIS A5905 (fiberboard) were used for the test.

The test items were bending strength, Young's modulus of bending, and rate of change of water absorption length, and the results are shown in Table 2.

Examples 1, 4, 5, 6, 9 and Comparative Examples 1, 2
Indicates the test results for the fiber orientation direction.

[0145]

[Table 1]

[0146]

[Table 2]

The kenaf fiberboards obtained in Examples 1 to 3 of the present invention are different from the fiberboard of Comparative Example 1 obtained by the conventional production method in comparison with the fiberboard of Comparative Example 1.
Since kenaf filaments having a longer fiber length of 200 mm or more are used, the strength characteristics and the dimensional stability are improved despite the same specific gravity.

Further, also for Comparative Example 3, the fiber diameter was 0.6.
Since the kenaf filaments defibrated to less than mm are used, both strength characteristics and dimensional stability are improved.

Further, the kenaf long fiber composite board obtained by the method shown in Examples 4 to 9 of the present invention has improved strength characteristics and dimensional stability as compared with Comparative Example 2 obtained by the conventional production method. did.

As described in Examples 1 to 9, the production method of the present invention can simplify the defibrating step or the adhesive dispersing step when producing a fiber board or a long fiber composite board. A long fiber mat can be easily formed while maintaining the oriented state of the long fibers, and a special fiber orientation process is unnecessary. Since the function of holding the mat shape is strengthened, the handleability of the mat is improved and the long fiber mat can be continuously formed.

Further, in the conventional manufacturing method, the fiber length of up to about 200 mm can be dealt with.
It is possible to use kenaf filaments having a length of 0 mm or more as a material, and it is possible to easily and uniformly disperse the adhesive. As a result, as shown in the examples, it is possible to manufacture a fiber board or a long fiber composite board with improved strength or dimensional stability.

That is, since the handling of the long fiber mat is improved and the mat can be continuously formed, it is possible to deal with continuous production, and the manufacturing process is greatly simplified as compared with the conventional manufacturing method. Therefore, the cost can be reduced. As a result, the production method of the present invention has enabled higher performance and lower cost.

[0153]

As described above, in the invention according to claim 1 of the present invention, the long fiber bundle obtained from the kenaf bast is
Multiple kenaf filaments are separated so that they are oriented in almost the same direction by arranging them so that the filament bundles are almost parallel and applying tension in the filament bundle direction without disturbing the fiber orientation. A defibration step, a step of dispersing the adhesive in the aggregate of the kenaf filaments oriented in the same direction obtained in the defibration step after the defibration step, and the kenaf filaments in which the adhesive is dispersed Since a matting step of forming a kenaf long fiber mat by stacking the aggregate of and a step of thermocompressing the formed long fiber mat,
A long fiber bundle obtained from the kenaf bast can be supplied to the defibration device as it is without slicing it, and the kenaf filaments can be disassembled into an aggregate in which they are oriented in almost the same direction. It can be formed at the same time as the fibers, and since long kenaf filaments are defibrated in a state of being oriented in almost the same direction, it is possible to disperse the adhesive evenly after that. In addition, since the long kenaf filaments are oriented in substantially the same direction and are entangled with each other, the shape retention of the mat is improved, the handleability is improved, and continuous production is possible. Therefore, compared with the conventional method, the defibration process, the adhesive dispersion process, etc. are simplified and the fiber orientation process is not required, and the fiberboard can be easily manufactured, and further, the long fiber bundle is not cut. However, since it can be defibrated by supplying it in the state of long long fiber bundles and can be defibrated into long kenaf long fibers, a fiber board that has a strong force to retain the mat shape and also improves strength characteristics It can be manufactured by a simple method.

According to the second aspect of the invention, a layer composed of a large number of kenaf filaments in which an adhesive is dispersed,
In a method for producing a long fiber composite board obtained by combining a plurality of layers composed of a large number of kenaf particles in which an adhesive is dispersed and thermocompressing the kenaf bast,
The long fiber bundle obtained from the
The fibers are arranged side by side while applying tension in the direction of the long fiber bundle.
By disintegrating without disturbing the orientation of
Disentanglement in which naphtho filaments are separated so that they are oriented in almost the same direction
The same as the process obtained after this defibration process
Disperse the adhesive in the directionally oriented kenaf filament fiber aggregate
Of the kenaf filaments in which the adhesive is dispersed
Forming kenaf filament mats by stacking aggregates
A matting step of forming, a step of forming a composite mat by laminating a plurality of mats composed of the kenaf particles and the long fiber mat after the matting step, and thermocompressing the composite mat. As a result, the long fiber composite board, which has a layer of kenaf filaments having a long length and a layer of kenaf particles, is laminated and is lightweight but strong. It can be obtained by a simple method of pressure molding, and in forming a kenaf filament mat, without cutting a long filament bundle of a long length obtained from the kenaf bast, as described above. It can be supplied to a defibration device as it is and defibrated to form an aggregate in which long kenaf filaments are oriented in substantially the same direction at the same time as defibration. Since long kenaf filaments are defibrated in the same orientation, it is possible to disperse the adhesive evenly after that, and it is also possible to disperse long kenaf filaments in substantially the same direction. Since the mats are oriented and aligned, the shape retention of the mat is improved, the handling is improved, and continuous production is possible, thus simplifying the defibration process and the adhesive dispersion process, etc., and aligning the fibers No steps are required, and a long fiber mat can be easily obtained. Moreover, even if the long fiber bundle is not cut, it can be supplied and defibrated in the state of a long long fiber bundle,
Since it can be defibrated into long kenaf filaments, a kenaf filament mat having a strong mat-holding force and improved strength characteristics can be produced by a simple method.

Further, in the invention of claim 3, after compounding a large number of kenaf filaments in which an adhesive is dispersed and a large number of kenaf particles in which an adhesive is dispersed, the kenaf particles are combined. In a method for producing a long fiber composite board obtained by thermocompressing a composite made of long fibers, a long fiber bundle obtained from a kenaf bast is formed into a long fiber bundle.
Arrange them so that the bundles are almost parallel, and set the
Solution without disturbing the fiber orientation.
By fiberizing many kenaf filaments in the same direction.
The defibration process that separates it like a
Kenaf long fiber maker obtained in the defibration process and oriented in the same direction
The step of dispersing the adhesive in the aggregate of
By stacking the aggregated kenaf filaments
A matting step of forming a kenaf long-fiber mat, a step of forming a composite mat by dispersing kenaf particles in voids of the long-fiber mat, following the matting step; Since it comprises a step of thermocompressing the composite mat, a large number of kenaf filaments in which an adhesive is dispersed and a large number of kenaf particles in which an adhesive is dispersed are compounded, and then the kenaf particles and long fibers are formed. By a simple method of thermocompression molding the composite, it is possible to obtain a long fiber composite board having the strength characteristics of long kenaf long fibers and the effect of weight reduction of kenaf particles. In forming the kenaf long fiber mat, the long fiber bundle obtained from the kenaf bast is supplied to the defibration device as it is without being cut, as described above. It is possible to defibrate and simultaneously form an aggregate in which long kenaf filaments are oriented in substantially the same direction at the same time as defibration.In addition, kenaf filaments with a long length are oriented in the same direction. Since it is made finer, it is possible to disperse the adhesive evenly after that, and since the long kenaf filaments are orientated in the same direction, the shape retention of the mat is improved. The handling is improved and continuous production is possible. Therefore, compared with the conventional method, the defibration process, the adhesive dispersion process, etc. are simplified and the fiber orientation process is not required, and a long fiber mat can be easily obtained. In addition, since it is possible to defibrate by supplying the long fiber bundle in a state of a long long fiber bundle without cutting the long fiber bundle, it is possible to defibrate a long kenaf long fiber,
A kenaf filament mat having a strong mat shape holding force and improved strength characteristics can be produced by a simple method.

In the invention according to claim 4, in the matting step of forming the long fiber mat according to the first aspect, a plurality of long fiber mats are laminated so that their fiber directions are orthogonal to each other. Therefore, it is possible to increase the strength in the bidirectional direction in which the kenaf filament is oriented, reduce the anisotropy of the strength, and suppress the dimensional change in the bidirectional orientation in terms of dimensional stability. As a result, the anisotropy of dimensional change can be reduced, and as a result, a fiber board with little strength and anisotropy of dimensional change can be easily manufactured.

[0157] In the invention according to claim 5, in the matting step of forming the long fiber mat according to the second or second aspect, a plurality of long fiber mats have their fiber directions orthogonal to each other. Since it is laminated in such a manner, it is possible to increase the strength in the bidirectional direction in which the kenaf filaments are oriented, reduce the anisotropy of the strength, and also in terms of dimensional stability, the bidirectional dimension in the oriented direction. Change can be suppressed,
Anisotropy of dimensional change can be reduced, and as a result,
The long fiber composite board having little anisotropy in strength and dimensional change can be easily manufactured.

Further, in the invention of claim 6, in claim 1 or claim 4, after forming a long fiber mat comprising an aggregate of kenaf long fibers in which an adhesive is dispersed, the long fiber mat is formed. By performing needle punching processing on the fiber mat, the kenaf long fibers are entangled with each other,
The entanglement of long kenaf fibers can reduce the anisotropy of strength and dimensional change, and as a result, a fiberboard having extremely high strength and excellent dimensional stability in the in-plane direction can be produced by a simple method. It is possible.

Further, in claim 7, after forming a long fiber mat comprising an aggregate of kenaf long fibers in which an adhesive is dispersed in claim 2 or claim 3 or claim 5, By performing needle punching treatment on the long fiber mat, the kenaf long fibers are intertwined with each other, so that the kenaf long fibers are intertwined with each other, so that the entanglement of the kenaf long fibers can reduce the anisotropy of strength and dimensional change. As a result, a long fiber composite board having extremely high strength and excellent dimensional stability in the in-plane direction can be manufactured by a simple method.

[Brief description of drawings]

FIG. 1 is a perspective view showing a kenaf long fiber bundle used in the present invention.

FIG. 2 is an explanatory view showing a state of defibrating by the defibrating device of the above.

FIG. 3 is an explanatory view showing a state in which an adhesive is dispersed by the adhesive spray device of the above.

FIG. 4 is an explanatory diagram showing a state in which the adhesive is dispersed by the adhesive dispersion device of the above.

FIG. 5 is a perspective view of an assembly of kenaf filaments in which the above adhesive is dispersed.

FIG. 6 is a perspective view of the above kenaf filament mat.

FIG. 7 is a perspective view showing the unidirectionally oriented fiber layer of the above.

FIG. 8 is a perspective view showing a state where the aggregate of kenaf filaments of the same is matted.

FIG. 9 is an explanatory diagram for explaining a method for manufacturing the above long fiber composite board.

FIG. 10 is a perspective view of the above long fiber composite board.

FIG. 11 is an explanatory diagram for explaining another method for manufacturing the long fiber composite board of the same.

FIG. 12 is an explanatory view of a method of defibrating the above-mentioned kenaf long fiber bundle, dispersing the adhesive, and rolling the kenaf long fiber mat into a roll.

FIG. 13 is an explanatory diagram for explaining still another method of manufacturing the long fiber composite board of the above.

FIG. 14 is a partially cutaway perspective view of the above long fiber composite board.

FIG. 15 is an explanatory diagram for explaining still another method for manufacturing the long fiber composite board of the above.

FIG. 16 is a cross-sectional view of a long fiber composite board formed from a composite mat in which kenaf particles are dispersed in void portions of the above kenaf long fiber mat.

FIG. 17 is an explanatory diagram of an apparatus for dispersing an adhesive in kenaf particles of the above.

FIG. 18 is a perspective view showing another example of the above continuous fiber composite board.

FIG. 19 is a perspective view showing the above-mentioned orthogonally oriented fiber layer.

FIG. 20 is an explanatory view showing a state in which a kenaf long fiber mat oriented in the above two directions is manufactured.

FIG. 21 is an explanatory view showing an example in which a kenaf filament is entangled by needle punching same as above.

FIG. 22 is a perspective view of a kenaf long fiber mat in which the above kenaf long fibers are entangled.

FIG. 23 is a perspective view of the fiber board of the same.

[Explanation of symbols]

1 kenaf filament 2 fiberboard 3 long fiber bundle 4 Kenaf long fiber mat 5 Kenaf particles 6 mat 7 composite mat 8 composite mat 9 aggregate 12 Adhesive

Front page continued (72) Inventor Ryo Sugawara 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Inventor Shuichi Kawai 70-35, Fukakusa Taniguchi-cho, Fushimi-ku, Kyoto (56) References JP-A-11 -333986 (JP, A) JP 63-272501 (JP, A) JP 10-264117 (JP, A) JP 10-305409 (JP, A) Actual development Sho 58-175921 (JP, U) ) (58) Fields investigated (Int.Cl. ⁷ , DB name) B27N 3/00-3/04

Claims (7)

(57) [Claims] 1. A method for producing a fiberboard obtained by thermocompressing a large number of kenaf filaments in which an adhesive is dispersed, wherein the filament bundle obtained from the kenaf bast portion is almost the same as the filament bundle. A defibration process in which a large number of kenaf long fibers are separated so as to be oriented in substantially the same direction by defibrating the fibers without disturbing the orientation of the fibers while applying the tension in the long fiber bundle direction in parallel. After this defibration process,
A step of dispersing an adhesive in an assembly of kenaf long fibers oriented in the same direction obtained in the disentanglement step, and a stack of the kenaf long fibers in which the adhesive is dispersed to form a kenaf long fiber mat. A method for producing a fiberboard, which comprises a matting step of forming and a step of thermocompressing the formed kenaf filament mat. 2. A long fiber obtained by combining a plurality of layers of kenaf filaments in which an adhesive is dispersed and a layer of a large number of kenaf particles in which an adhesive is dispersed and thermocompressing them. In the method for manufacturing the composite board, the long fiber bundle obtained from the kenaf bast is
Arrange them so that they are almost parallel and tension them in the direction of the long fiber bundle.
Defibrate while applying the fiber without disturbing the fiber orientation
By doing so, many kenaf filaments are oriented in almost the same direction.
And the defibration process
Of kenaf long fiber work oriented in the same direction
The process of dispersing the adhesive in the body and before the adhesive is dispersed
Kenaf is made by stacking an aggregate of long fibers.
A matting step of forming a long fiber mat, a step of forming a composite mat by laminating a plurality of mats composed of the kenaf particles and the long fiber mat after the matting step, and forming the composite mat; A process for producing a long fiber composite board, which comprises the step of thermocompression molding. 3. A composite of a large number of kenaf filaments in which an adhesive is dispersed and a large number of kenaf particles in which an adhesive is dispersed, and then a composite of the kenaf particles and long fibers is thermocompression molded. In the method for producing the long fiber composite board obtained by
Align long fiber bundles so that they are almost parallel
Distorts the fiber orientation while applying tension in the fiber bundle direction.
Do not defibrate so that many kenaf filaments
This is the defibration process in which the fibers are separated so that they face in the same direction.
Next to the defibration process, align in the same direction obtained in the defibration process.
The process of dispersing the adhesive in the aggregate of kenaf long fiber workers
And an aggregate of the above-mentioned kenaf long fibers in which an adhesive is dispersed.
The mat that forms a kenaf filament mat by layering
A matting step, a step of forming a composite mat by dispersing kenaf particles in the voids of the long fiber mat, and a step of thermocompressing the composite mat after the matting step. And a method for producing a long fiber composite board. 4. The method for producing a fiber board according to claim 1, wherein in the matting step of forming the long fiber mat, a plurality of long fiber mats are laminated so that their respective fiber directions are orthogonal to each other. 5. The continuous fiber according to claim 2, wherein a plurality of continuous fiber mats are laminated in a matting step of forming a continuous fiber mat so that the fiber directions of the continuous fiber mates are orthogonal to each other. Manufacturing method of composite board. 6. The kenaf filaments are entangled with each other by forming a filament mat made of an aggregate of kenaf filaments in which an adhesive is dispersed and then subjecting the filament mat to a needle punching treatment. Claim 1
Or the manufacturing method of the fiber board of Claim 4. 7. The kenaf long fibers are entangled with each other by forming a long fiber mat made of an aggregate of kenaf long fibers in which an adhesive is dispersed, and then subjecting the long fiber mat to needle punching treatment. Claim 2
Alternatively, the method for manufacturing the long fiber composite board according to claim 3 or claim 5.