JPH0641123B2 - Method for manufacturing wood-based molded body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention provides a wood-based molding material in which a wood fiber is mixed with a binder containing a synthetic resin and the like, and the wood-based molding material is heat-compressed and molded. A method of manufacturing a body.

(Prior Art) This type of wood-based molded product is lighter than plywood, has excellent heat resistance, water resistance, and moisture resistance, and has high strength for its thickness. It is widely used for interior materials, furniture, interior materials for automobiles, televisions, cabinets such as stereos.

Conventionally, in order to produce the above wood-based molded body, generally, a wood fiber obtained by steaming and defibrating wood chips is combined with a binder such as a phenol resin, hemp fiber, or a water repellent such as rosin or paraffin. After blending and depositing it to a suitable thickness, it is lightly heat-compressed and molded by, for example, a roll press to form a so-called molding mat (thickness, 10 to 40 mm), and then the mat is appropriately cut and molded. A method has been adopted in which it is supplied to a mold and thermocompression-molded into a predetermined shape.

(Problems to be Solved by the Invention) However, according to the above-described conventional manufacturing method, matting is an indispensable requirement, so that the process becomes complicated and the productivity cannot be improved as expected, and in addition, There is a problem that cutting becomes indispensable, the yield is reduced accordingly, and the manufacturing cost is increased as a whole.

In addition, when a large plate-shaped body having a deep-drawn portion is formed with a single mat, it becomes difficult for the mat material (wood fiber) to flow into the deep-drawn portion, and the corners become thin, which results from this. In many cases, there were skeins and cracks. As a countermeasure against this, the amount of hemp fiber used is increased, but in this case, it is necessary to add an extra synthetic resin, which causes an increase in raw material cost and an unavoidable increase in product cost. .

Therefore, the inventors of the present application gathered the wood-based molding material in a predetermined shape in advance and supplied it to the molding die (Japanese Patent Application No. 60-230483).
No.) or a method for producing a wood-based molded body by supplying the molding material to a fibrous or mould-forming mold (Japanese Patent Application No. 60-259372) and performing thermal compression molding. It has solved various problems caused by its use.

By the way, according to these methods, when the binder (synthetic resin) is included in the wood fiber, the distribution of the binder varies among the fibers, and the surface swelling and the density variation occur in the subsequent thermal compression molding. There is a risk of inducing and impairing the quality of the molded body.

Most of the wood-based molded products are put to practical use by sticking a skin such as vinyl chloride, but when the rich portion of the binder is mixed in the molding material, when the skin is stuck after the compression molding. For example, when high frequency welding is adopted, sparks are likely to occur and the molded body may be damaged, which has been a problem.

The present invention has been made in order to solve the above-mentioned conventional problems, and improves the yield and productivity by eliminating the need for matting, and the heat compression by making the weight of the molding material uniform. It is an object of the present invention to provide a method for producing a wood-based molded product that has improved moldability.

(Means for Solving Problems) Therefore, according to the present invention, a wood-based molding material is obtained by including a binder or the like in wood fibers, and subsequently, the binder-rich portion is removed from the molding material, and after that, The gist of the present invention is that the fibers or aggregates are assembled into a predetermined shape, supplied to a molding die, and subjected to thermocompression molding.

The wood fiber used in the present invention is obtained by defibrating wood chips and the like, and the wood used and the defibration method thereof are not particularly limited. For example, as the wood, cypress, red pine, cedar, lauan, beech and the like can be used, and as the defibration method, a method of steaming with steam and then mechanically loosening can be used.

The binder contained in the wood fiber may be one having a property of supplementing the caking property of the wood fiber itself, and for example, a thermoplastic resin such as coumarone resin or a thermosetting resin such as a phenol resin or a urea resin. Can be used. In addition to this binder, a water repellent agent or a release agent for improving water resistance can be included.

In the manufacturing method of the present invention, as described above, it includes the content of supplying the wood-based molding material to the fibrous or molding die to perform compression molding. In this case, for example, the upper and lower molds constituting the molding die are The molding materials are preliminarily aligned at a predetermined interval and placed on an air flow to fill the molding material with the molding material. On the other hand, when the wood-based molding material is assembled into a predetermined shape and then supplied into the mold, for example, a laminating container provided with a wire net, punching metal or the like is provided, and the molding material is sucked into the container to suck the metal net. It may be arranged such that it is piled up, then held by suction in a separately provided holder, conveyed to the top of the molding die, and subsequently, the suction is released to drop it into the die.

Further, in order to remove the rich portion of the binder from the wood-based molding material, for example, a vertical classification container is provided, the molding material is dropped from the upper part of this container, and the lightweight portion is sucked and discharged from the middle thereof, It is possible to employ a method in which a heavy portion rich in binder is dropped under the container.

(Operation) In the method for manufacturing a wood-based molded product configured as described above, since the wood-based molding material is directly supplied to the molding die, matting is not necessary, and the yield is improved and the process is simplified. Can be achieved. Further, since the compression is started from a state in which the wood fibers are less entangled, the compression moldability is improved and the molding including the deep-drawn portion is facilitated. Furthermore, by removing the rich portion of the binder from the wood-based molding material, in the subsequent compression molding process, it is possible to produce a quality stable molding without surface swelling and density variation, and when the epidermis is welded to this with high frequency. It is possible to prevent the occurrence of sparks.

(Example) Hereinafter, an example of the present invention is described based on an accompanying drawing.

1 and 2 show an example of a schematic manufacturing process of a wood-based molded product according to the present invention. In FIG. 1, reference numeral 1 is a storage tank for storing wood chips W1, and the wood chips W1 conveyed from the storage tank 1 reach a chip washing machine 2 to be subjected to a washing action, and are subsequently conveyed to a defibrating machine 3, where It is made into fibers by being steamed and defibrated. At this time, the water repellant is supplied from the pump 4 to the defibrating machine 2. The fibrous wood fiber W2 is conveyed to the hot air tube 5a of the dryer 5 and placed on the hot air from the dryer 5b to reach the cyclone 5c, where it is dried. The dried wood fiber W2 is conveyed to the hopper 6a of the mixer 6 and then reaches the main body 6b of the mixer 6, where the binder,
It is mixed with a water resistant agent and transported to the next step.

The fibrous mixture (wooden molding material) M conveyed from the mixer 6 is subjected to a laminating action from above in a collecting device 10 and is subjected to a predetermined operation, as shown in FIG. The material aggregate W having a shape is formed, then transferred to the holder 20, conveyed to the molding device 30, and put into the lower mold 31 of the molding device 30. The raw material aggregate W put into the lower die 31 is subjected to a heating action there, and is then compressed by the upper die 32 of the forming device 30 to be formed into a formed body P having a predetermined shape.

Hereinafter, the details of each step will be described with reference to other drawings.

As shown in FIG. 3, the defibrating machine 3 includes a chip washing machine 2
A hopper 3a for temporarily storing the wood chips W1 conveyed from (FIG. 1), and a first screw feeder 3b provided under the hopper 3a for quantitatively feeding the wood chips W1.
A steaming tank 3c for steaming the wood chips W1 supplied from the first screw feeder 3b, and a second screw feeder 3d provided under the steaming tank 3c for quantitatively feeding the steamed wood chips W1. And a defibration disc 3e for mechanically defibrating the wood chips W1 supplied from the second screw feeder 3d.

Steam S is supplied to the steaming tank 3c from above, and the wood chips W1 supplied therein are supplied.
Is agitated by the agitating rod 3f and steamed by the steam, so that the fiber is easily disintegrated. The wood chips W1 thus steamed are further processed by the second screw feeder 3
It is conveyed to the defibration disc 3e by d, mechanically defibrated there, and then conveyed to the dryer 5 (FIG. 1) via the pressure feed pipe 3g.

As shown in FIG. 4, the main body 6b of the mixer 6 has a cylindrical case 6c in which a stirring blade 6d is rotatably incorporated, and one end of the case 6c is provided with the hopper 6a (first
From the drawing), a receiving port 6d for taking in the wood fiber W2 and a spray nozzle 6e for supplying a binder such as a phenol resin or a waterproofing agent such as paraffin are provided, and the mixture M (at the other end of the case 6c). It has a discharge port 6f for discharging (FIG. 2).

As a result, the wood fibers W2 taken in from the receiving port 6d to one end of the case 6c are combined with the binder, water resistant agent, etc. injected from the spray nozzle 6e there, and the stirring blades are driven to rotate by a drive means (not shown). 6d mixes well, sequentially moves to the discharge port 6f side, is discharged from there, and is further carried out to the next step.

The mixture M carried out from the mixer 6 is put into the classification device 40 shown in FIG. In FIG. 5, 41 is
This is a classification container that is vertically fixed and fixed to the pedestal 42 and has an open lower end, and integrally has a discharge pipe 41a that extends obliquely upward at the upper end thereof. Inside the classification container 41, a plurality of classification plates 43, 43
... are provided so as to be swingable by alternately changing the direction in the vertical direction. The free end of each classification plate 43 is the classification container 41.
It is supported by an eccentric cam 44 rotatably disposed therein, and an appropriate inclination angle can be taken by the rotation of the eccentric cam 44. That is, this classification plate 4
3 is capable of forming classifying portions 45, 45, ... Having a predetermined opening between the eccentric cam 44 and the inclined state maintained by being supported by the eccentric cam 44. Has become.

A fluffer case 46 is connected to the upper end of the classification container 41 so as to communicate with it. This fluffer case 46 has the upper end thereof with the mixer 6 (see FIGS. 1 and 4).
Inlet 4 for receiving the mixture M conveyed from the drawing)
7 is provided integrally, and a pair of fluffer rolls 48 that mesh with each other are provided inside thereof. The fluffer roll 48 plays a role of loosening the mixture M. The mixture M dropped from the receiving port 47 is loosened by the fluffer roll 48, and then the classification container 41.
It will fall inside.

On the other hand, below the classification container 41, a conveyor 49 for receiving the mixture falling from the classification container 41 is arranged. The conveyor 49 is supported by a supporting member 51 having a supporting roller 50 under the classification container 41, and can stably receive the falling mixture. Further, a height sensor (for example, a photoelectric tube) 52 is arranged above the conveyor 49. The height sensor 52 serves to quantitatively measure the mixture falling from the classification container 41.

A suction unit 53 having a built-in suction fan is connected to the discharge pipe 41a of the classification container 41 via a suction pipe 54 so that the inside of the classification container 41 is exhausted. A storage case 54 for storing the mixture is attached to the conveyor 49.

In the classifying device 40 as described above, the mixer 6 in the previous step
The mixture M that has been conveyed from the above and introduced from the inlet 47 of the fluffer case 46 is loosened by the fluffer roll 48 and then drops into the classification container 41. At this time, an ascending air current is generated in the classification container 41 due to the operation of the suction fan in the suction unit 53, and the dropped mixture M
While passing through the classifying section 45 defined by each classifying plate 43, the lightweight mixture containing a proper amount of the binder is put on the ascending air current and soars, and passes through the discharge pipe 42 and the suction pipe 54. It is sucked into the suction unit 53. On the other hand, since the binder rich portion in the mixture M has a heavy weight, it gradually moves to the lower side of the classification container 41, finally falls from the lower end opening thereof onto the conveyor 49, and is further conveyed to the conveyor 49 and stored. It reaches the container 54. The mixture introduced into the suction unit 53 is carried out to the collecting device 10 (Fig. 2).

In this way, the binder-rich portion is removed from the mixture M, and only the wood-based fibers containing the binder are uniformly delivered to the next step. The classification level at this time can be arbitrarily adjusted by the opening area of the classification section 45 (the inclination angle of the classification plate 43) or the suction force of the suction unit 53. In this case, the adjustment amount is determined with reference to the amount of the binder rich portion obtained by the height sensor 52.

By the way, the collecting apparatus 10 for obtaining the material assembly W from the mixture M is configured as shown in FIG. 6 as an example. That is, the collecting device 10 is roughly configured by a spraying container 11 in which an iron plate or the like is formed in a roof shape, and a stacking container 12 which is fitted to the lower side of the spraying container 11 and stacks the mixture M. At the upper opening of the spraying container 11, a sprayer 13 for spraying the mixture M, and an air blowing container 14, 14 having an air outlet for controlling the spraying direction of the mixture M sprayed from the sprayer 13 are provided inside. Is provided, and each air outlet container 14 has an air supply pipe 15,
The air switched by the switching valve 16 is supplied via 15. Further, the above-mentioned stacking container 12
A suction pipe 17 for sucking the inside of the stacking container 12 is connected to the bottom side of the, and a shaping member 1 such as a wire mesh or a punching metal that regulates the bottom shape of the assembly is connected to the top thereof.
8 are stretched. The stacking container 12 is integrally provided with a guide plate 12a for fitting the spraying container 11 therein. Further, in this stacking container 12, the lower structure including the suction pipe 17 can be separated.

With such a configuration, first, the switching valve 16 is opened to supply air from the air supply pipe 15 to the air blowing container 14 to form an air flow from the spraying container 11 to the stacking container 12, and then this air is supplied. The mixture M is discharged from the sprinkler 13 with respect to the above flow. The mixture M is placed on the air and descends in a floating state to the stacking container 12, and is sequentially deposited on the shaping member 18. At this time, the air ejected from the left and right air blowing containers 14, 14 is switched by the switching valve 16 to change the descending direction of the mixture M so that the mixture M is scattered all over the shaping member 18 and is thickly deposited at a necessary portion. Further, at this time, air is sucked from the bottom side of the stacking container 12 through the suction pipe 17 to promote rapid deposition of the mixture M.

In this way, the stacking of the mixture M proceeds, and finally the raw material aggregate W having a predetermined shape can be obtained. At this time, the supply of the mixture M from the sprayer 13 is stopped, and at the same time, the air supply pipe 28 is supplied. The air supply is also stopped, and the wood fiber lamination process is completed. The obtained raw material aggregate W has an extremely low density because it is simply laminated. Further, the thickness thereof is set larger than the desired thickness.

After the stacking is completed, the stacking container 12 is separated from the spraying container 11 and the stacking upper surface is flattened (not shown), and then the stacking container 12 is changed to the cage 20 as shown in FIGS. 7 and 8. Reprint. That is, the cage 20 has a main body 21 having a shape that can be fitted to the stacking container 12, a support member 22 made of wire mesh, and the suction pipe 23 connected to the upper side of the main body 21. When the inside of the main body 21 is sucked through the suction pipe 23 by a suction device (not shown) or the like, the material assembly W moves upward due to its low specific gravity and moves to the support member 22.
Is closely supported by. Then, while keeping this suction state, the holder 20 is lifted up, moved to the forming device 30 by a conveying means (not shown), positioned, and then the suction is released to put the material assembly W into the lower die 31 ( Second
Figure).

FIGS. 9 and 10 show the material aggregate W put in as described above.
2 shows the structure of a molding die for carrying out the compression molding of and its usage. In these figures, the lower die 31 is fixed on the heating plate 33, and the upper die 32 is fixed under the heating plate 34. An outer peripheral portion of the lower die 31 is surrounded by a holding frame 35, and a storage space for the material aggregate W is formed on the lower die 31. The upper die 32 can slide along the inner peripheral surface of the holding frame 35. Further, the upper mold 32 is provided with a plurality of gas vent holes 36, and the gas vent holes 36 are connected through a port 37 to a vacuuming means (not shown) by a pipe 38. A valve 39 is provided in the pipe 38.

With such a configuration, the lower mold 31 and the upper mold 3 are provided prior to compression molding.
2 is heated in advance by the heat plates 33 and 34, and first, the material assembly W is supplied onto the lower mold 31 surrounded by the holding frame 35 (FIG. 9). When the press upper ram (not shown) is lowered while waiting for the supply of the material aggregate W, the upper die 32 and the lower die 3
1, the material aggregate W is narrowed down, the entanglement of the wood fibers is gradually increased, and the density becomes high, and the molding pressure is increased accordingly. During this time, the switching valve 39 is opened to open the gas vent hole 3
Degas through 6.

In this way, it is finally hard and has a predetermined deep drawing P1.
A homogeneous wood-based molding P having Then,
The raw material aggregate W to be subjected to this compression molding has a substantially constant weight because the binder-rich portion is removed in the classification step, and a high-strength compact P having no defects such as surface blisters is obtained. You will get it. Material aggregate W
Since the wood fibers near the outer peripheral portion of the material hardly flow into the mold, the outer shape is completely formed and the subsequent outer shape removing step can be omitted.

Although the low-density material aggregate W was used as the wood-based molding material in the above-mentioned examples, the present invention instead uses the fibrous mixture M as the raw material of the material aggregate W. It can also be supplied to the molding die for compression molding.

FIG. 11 and FIG. 12 show an example of an apparatus for directly supplying the mixture M to the mold. In the figure, 60
Is a filling device, and the filling device 60 is a vertical supply container 61.
And a horizontal pressure feed container 62. The supply container 61 and the pressure-feeding container 62 communicate with each other through the opening 63,
The opening 63 is a shield plate 65 driven by a cylinder 64.
Can be opened and closed by. The supply container 61 is
A supply port 66 for the mixture M is provided at the upper end, and a pair of rotating brushes 67, 67 are installed above the opening 63. Further, the pressure-feeding container 62 has one end connected to a blower (not shown) and the other end (see FIGS. 9 and 10).
Weighing plate 6 tied to the compression mold shown in the drawing) and further connected to a load cell (not shown) at a portion located below the opening 63.
It has 8 interiors. On the other hand, the mold holding frame 35 is provided with a first opening 69 connected to the pressure-feeding container 62 and a second opening 70 connected to the outside on the opposite side. Opening 6
The reference numerals 9 and 70 have a vertical width corresponding to a space 71 in the mold which is semi-closed, and have an appropriate length. Further, the holding frame 35 is provided with doors 72 and 73 capable of opening and closing the openings 69 and 70 so as to be laterally slidable. Door body 7
As is clear from FIG. 12 which shows the one door body 72 side as a representative, the two and 73 have a window 74 having substantially the same size as the openings 69 and 70 on one side thereof, and in particular, 2 openings 7
The door 73 facing 0 has a wire mesh 75 attached to its window. Each door body 72, 73 is also provided with a rack 76 at its lower end, and a motor 78 is fixedly mounted on a bracket 77 protruding from the holding frame 35, and the rack 76 is attached to the output shaft of the motor 78. A pinion 79 that meshes with is attached. That is, the doors 72 and 73 have the motor 78.
Is driven to slide laterally to open the window 74 through the openings 69, 70.
It is possible to appropriately select a position to face the opening and a position to close the openings 69 and 70.

With such a configuration, the mixture M introduced into the supply container 61 through the supply port 66 is dropped from the opening 63 while the fibers of the mixture are untangled by the rotating brush 67, and the mixture M is placed on the weighing plate 68 in the pressure-feed container 62. Deposit on. Then, when a predetermined amount is accumulated, the cylinder 64 is operated and the opening 63 is closed by the shielding plate 65, and at this time, the wind from the blower blows,
The mixture M, which is sent as indicated by the arrow A and is deposited on the weighing plate 68, is placed on the air and sent to the space 71 in the mold.

The mixture M fed into the mold is prevented from advancing by the wire netting 75 and gradually accumulates in the void 71, while the air escapes through the wire netting 75 as shown by the arrow B to the outside. Finally, the empty space 71 is filled with the mixture M, and at this time, the motor 78 starts driving, the door bodies 72 and 73 slide, and the first and second openings 69 and 70 are closed.
After that, compression molding is performed in the same process as described with reference to FIGS. 9 and 10 above, and a high-quality wood-based molded product P can be obtained as in the above-described embodiment.

The devices used for manufacturing the above-mentioned wood-based molded product are merely examples, and it goes without saying that devices having other structures may be used.

(Effect of the invention) As described above in detail, according to the present invention, the wood-based molding material is supplied to the molding die for thermocompression molding.
As a result, matting is not required, and the yield can be improved and the process can be simplified.

Further, since the compression is started from a state where the wood fibers are less entangled, the compression moldability is improved, and a molded product including a deep-drawn portion can be manufactured with high quality without defects such as scallops and cracks. . And by improving this moldability, not only can the amount of binder contained in the wood fiber be reduced,
Since the addition of hemp fiber is unnecessary, the effect of achieving a significant reduction in manufacturing cost is achieved.

Furthermore, by removing the rich portion of the binder from the wood-based molding material, surface swelling and density variation can be eliminated in the subsequent compression molding process, and it is possible to produce a high-quality wood-based molding. . Further, by removing the rich portion of the binder as described above, it becomes possible to high-frequency welding the skin to the obtained molded product without the generation of sparks, and the wood-based molded product obtained by this method is remarkably applicable. This has the effect of expanding the range.

[Brief description of drawings]

FIGS. 1 and 2 show an example of a manufacturing process of a wood-based molded body according to the present invention. FIG. 1 is a manufacturing process drawing of a molding material, and FIG. 2 uses the molding material. Molding process diagram,
FIGS. 3 to 10 show an example of the structure of an apparatus for manufacturing the present wood-based molded product and an example of its usage. FIG. 3 is a schematic diagram of a defibrating machine, and FIG. 4 is a mixer. FIG. 5, FIG. 5 is a schematic diagram of a classifying device, FIG. 6 is a sectional view of a collecting device, FIGS. 7 and 8 are sectional views of a cage, and FIGS.
The figure is a cross-sectional view of the molding die, and Figs. 11 and 12 show another example of an apparatus for manufacturing a wood-based molded body. Fig. 11 is a cross-sectional view, and Fig. 12 is a part thereof. FIG. 3 ... Defibrator, 6 ... Mixer 10 ... Collecting device, 20 ... Retainer, 30 ... Molding device, 31 ... Lower mold 32 ... Upper mold, 40 ... Classifying device 60 ... Filling device, M ... Mixture W ... Material aggregate , P ... Wooden molding

Claims (1)

[Claims] 1. A wood-based molding material is obtained by adding a binder containing a synthetic resin or the like to wood fibers, and subsequently, the binder-rich portion is removed from the molding material, and thereafter the fibers are assembled into a fibrous or predetermined shape. A method for producing a wood-based molded product, which comprises: