JP3488566B2 - Dimensional stabilization method for wood - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimensional stabilization treatment method for wood materials, and more particularly to a treatment method for wood materials by improving the dimensional stability of wood materials by supplying high-pressure steam into the wood materials. Regarding the improvement of the method.

[0002]

BACKGROUND ART Wood swells or contracts by absorbing and releasing water. This means solid sawn wood, thin wood (thickness 0.2
mm to 10 mm), particle board, MDF, O
The same applies to SB and the like. When a wood material is used as a building or furniture material, it is not preferable that the wood material swells or shrinks depending on the environment, and it is desired that the wood material has dimensional stability independent of the environment.

As a countermeasure therefor, a method has been used in which a wood material is vertically sandwiched by a press board, placed in an autoclave, and treated with high-pressure steam for several minutes to stabilize the size of the wood material. However, in this method, in addition to large-scale equipment, it is difficult for high-pressure steam to penetrate into the interior of the wood material (central part), and the treatment conditions at the central part and the peripheral part of the wood material may differ.

The present applicant has conducted many experiments and researches to eliminate the inconvenience, and arranges a wood material to be treated between the heating plates of a flat plate press having a heating plate used in conventional wood processing, Further, an elastic sealing material such as an elastic silicon material and a required thickness controlling jig such as a stainless material are further arranged around the peripheral sealing material and sealed, and then high pressure steam is supplied from steam supply holes provided in the upper and lower heating plates. Has been proposed to stabilize the dimension of wood materials (Japanese Patent Laid-Open No. 6-238616).

[0005]

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-238
The treatment method described in Japanese Patent No. 616 can be performed by using a flat plate press having an ordinary hot platen used for compressing wood and manufacturing composite materials, and simplifies the dimensional stabilization treatment of wood materials. Have the advantage of The present inventors, in the process of performing dimensional stabilization of the wood material by the above treatment method, depending on the specific gravity and thickness / size of the wood material, its surface state, etc.,
It was experienced that high-pressure steam was not uniformly supplied to the inside of the wood material, and as a result, the desired dimensional stability could not be achieved. In addition, the degree of sealing between the elastic sealing material and the heating plate becomes non-uniform, and high-pressure steam may partially leak to the outside from a portion having a low degree of sealing.

An object of the present invention is to further improve the dimensional stabilization treatment method for the wood material, more specifically, the steam to be supplied is surely permeated to the inside of the wood material and uniformly supplied. Therefore, it is an object of the present invention to provide a dimensional stabilization treatment method in which high dimensional stability is always provided regardless of the type of wood material. Another object of the present invention is to provide a dimension stabilization treatment method which prevents water vapor from leaking out from the space between the heating plates and enables continuous stable treatment. Further, it is an object of the present invention to provide a processing method capable of achieving high dimensional stability in a shorter processing time.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention basically involves sandwiching a wood material between two press boards and applying high pressure steam from one press board side to the wood material. Disclosed is a method for dimensional stabilizing treatment of a wood material, which is characterized in that the wood material is supplied toward the wood material and the other press board side is evacuated.

In the present invention, the wood material to be treated is not particularly limited, and not only solid wood such as veneer but also medium fiber board (M
Woodworking materials such as DF), oriented board (OSB) and particle board can also be processed. In the case of a woodworking material, it is particularly effective to carry out the treatment of the present invention while applying pressure and compression with a press board. The press platen used in the present invention may be a press platen mounted on a flat plate press conventionally used for compaction of wood and production of composite materials, and may or may not have a heat source. Good. When the press board has a large number of pores communicating with the outside, the pores of one press board are connected to a conventionally known high-pressure steam generation source through appropriate pipes and valve means, etc., The pores of the other press platen are connected to a vacuum source such as a conventionally known and preferably heat-resistant vacuum pump through appropriate pipes and valve means. Preferably, a suction blower is arranged in the evacuation side pipe. As a result, it becomes possible to supply high-pressure steam to the wood material through the press board and to evacuate the wood material.

As another method of supplying steam and vacuuming, another member having a large number of pores and having pressure resistance and heat resistance may be arranged between the upper and lower press plates and the wood material. You may In that case, one said separate member is connected to a high pressure steam generation source, and the other said separate member is connected to a vacuum source. As a result, it becomes possible to supply high-pressure steam to the wood material through the pores of the separate member and to perform vacuuming. A preferred embodiment of this type of separate member is composed of a box-shaped member having an internal space capable of accommodating a wood material to be treated and a lid member for sealing the internal space. In either method, the press board may be in a heated state or a non-heated state by a heat source.

The wood material to be treated may be arranged between the two press plates with their perimeters open, so that a sealed space is formed between the two press plates and the wood material is arranged in the sealed space. You may In the former case, it is preferable to form the large number of pores in the area where the surface of the press board or the separate member abuts the wood material to be treated. In the latter case, the pores may be formed on all of the surface portions located in the sealed space, but in this case also, it is preferable to form the pores in the area that abuts the wood material to be treated.

Further, preferably, a thickness regulating jig for regulating the thickness of the treated wood material is arranged between the two press plates. The material of the thickness regulating jig may be a member having necessary rigidity and heat resistance, and aluminum material, stainless material, etc. are preferably used. As described above, when a separate member composed of a box-shaped member and a lid member is used, it is possible to form a sealed space whose thickness is regulated by itself, and a special thickness regulation jig is used. There is no need to use a tool.

The method for forming the sealed space between the two press plates is arbitrary, but for example, the elasticity of the circumference of the wood material to be treated is slightly higher than the thickness of the wood material after the treatment. It is effective to arrange a sealing material and bring the upper and lower press plates close to each other so that the internal space surrounded by the elastic sealing material becomes a sealed space. As the elastic sealing material, any material can be used as long as it has a sealing function of not leaking the high-pressure steam ejected from the press plate or the separate member to the outside and has heat resistance and compressibility. Packing materials are particularly preferred. In this case, the thickness regulating jig is arranged outside the elastic sealing material.

In the processing, the pores of one press board (or another member) are connected to the high-pressure steam supply source, and the pores of the other press board (or another member) are connected to the evacuation means side. After arranging the elastic sealing material and the thickness regulating jig on the press plate (or another member) located below, in consideration of the positions of the pores provided on the press plate (or another member), if necessary. , Place wood materials.

If necessary, the upper and lower press plates are brought close to each other while the press plates are heated by a heat source, and the wood material is sandwiched between the two press plates (or separate members). The sandwiching may be sandwiching the wood material under a non-compressed state, or may be sandwiched under a pressure-compressed state. When the elastic sealing material and the thickness regulating jig are used, the wood material is subjected to the amount of compression regulated by the thickness regulating jig in the sealed space defined by the elastic sealing material. It is also possible to perform processing using only the thickness control jig without using the elastic sealing material.

In that state, the circuit on the side of the high-pressure steam generator is opened, and saturated steam or superheated steam (higher than saturated steam) of preferably 180 ° C. or higher is directed toward the wood material from the pores of one press board (or another member). At the same time as ejecting steam (temperature steam), the evacuation means such as a vacuum pump is driven to perform evacuation from the pores of the other press platen (or another member). As a result, in addition to the jetting force, suction force acts on the water vapor ejected from the pores of the press board (or another member) toward the wood material, and the water vapor is ejected from the surface of the wood material (and in some cases, the surrounding area) Kinetic energy toward the other press platen (or another member) increases. As a result, the high-pressure steam is surely transmitted to the interior of the wood material in a shorter time than the conventional method, and is evenly and uniformly distributed. As a result, the dimensional stabilization process proceeds rapidly and over the entire area.

When vacuuming is performed at the same time when the supply of high-pressure steam is started, depending on the type of the wood material, the high-pressure steam does not sufficiently penetrate into the wood material, and the high-pressure steam directly passes through the surrounding space to the outside. It may be discharged. In such a case, prior to the start of the supply of high-pressure steam, the vacuuming means such as a vacuum pump is driven to perform vacuuming, and the sealed space formed between the press plates is preliminarily depressurized, and then high pressure is applied. It is recommended to start the supply of steam. By being in a decompressed state,
The supplied high-pressure steam can easily penetrate into the wood material, and the supply loss of the high-pressure steam is eliminated. After vacuuming and depressurizing the sealed space, shut off the valve and stop the vacuuming, supply high pressure steam into the depressurized sealed space so that high pressure steam permeates the wood material. Good. In this case, since the release of the high-pressure steam to the outside is reliably suppressed, the loss of steam can be eliminated. Furthermore, after supplying a predetermined amount of high-pressure steam into the sealed space that has been depressurized as described above,
The high-pressure steam may be supplied while evacuating again. In this case, the high-pressure steam can be effectively used and the processing can be speeded up. Further, high-pressure steam may be supplied into the sealed space that is not evacuated, and the evacuation may be started when a certain amount of water vapor permeates the wood material.

The optimum treatment conditions are determined experimentally depending on the type and size of the target wood material, but the pressure of the high-pressure steam is several kgf / cm ^{2 to} 30 kgf / cm.
^{2. The} temperature is preferably about 150 ° C to 230 ° C. As mentioned above, the initial thickness of the wood material to be treated in the present invention may be about the same as or thicker than the desired final product thickness. In the former case, so-called consolidation treatment is not performed, but in the latter case, dimensional stabilization treatment is performed together with consolidation treatment.

The decompression may be carried out immediately after the ejection of the predetermined high-pressure steam is finished, or the decompression may be carried out by leaving it for a predetermined time for a while. The decompression may be performed gradually over a certain period of time, or may be performed in a so-called cold state by supplying cooling water to the hot platen. According to the experiment, the dimensional change rate of the obtained final product was smaller and the surface condition was smoother when the decompression was performed in the cold state than when the decompression was gradually performed.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail with reference to the drawings. FIG. 1 shows an example of an apparatus for carrying out the method for stabilizing the dimension of wood material according to the present invention. In the figure, 1a and 1b are press plates similar to those mounted on a flat plate press used in conventional wood processing, each provided with a heater 2a and 2b as a heat source, and a wood material W to be processed. A large number of pores 3a, 3b are formed in the surface portion that comes into contact with. The pores 3a formed in the upper press platen 1a are connected to the high-pressure steam generation source S via the pipe 4a and the opening / closing valve V, and the pores 3b formed in the lower press platen 1b are connected via the pipe 4b. Connected to the vacuum pump VP. A blower (not shown in FIG. 1) may be used instead of the vacuum pump.

In carrying out the treatment method according to the present invention using this apparatus, first, a flat wood material W is placed as a treatment material on the lower press board 1b at a position where the pores 3b are formed. Then, the thickness regulating jig 10 made of stainless steel or the like is arranged on the side of the jig. The height of the thickness regulating jig 10 is the same as or slightly lower than the thickness of the wood material W. Next, the press plates 1a and 1b are brought close to each other until they are regulated by the thickness regulating jig 10 and stopped. Although not shown, a sealing material may be arranged around the wooden material W as described above to form a sealed space between the press plates 1a and 1b.

In this state, the pipe 4 on the side of the high-pressure steam generator S
The on-off valve V provided in a is opened, high-pressure steam is ejected from the pores 3a formed in the press board 1a, and at the same time, the vacuum pump VP (or blower) is operated to form the thin film formed in the press board 1b below. A vacuum is drawn from the hole 3b. The water vapor ejected from the pores 3a toward the wood material W receives the force due to the suction force in addition to the ejection force and can easily and uniformly reach the inside of the wood material W of the wood material. Further, since the evacuation is performed, the high-pressure steam does not leak to the outside, the waste of the high-pressure steam is eliminated, and the safety of the surroundings is compensated.

The vacuum pump VP (or blower) is stopped immediately after or immediately before the ejection of a desired amount of high-pressure steam, and thereafter, in the same manner as in the conventional method,
By performing the decompression and cooling steps, the method for stabilizing dimension of wood material according to the present invention is completed.

When a sealing material is arranged around the wood material W to form a sealed space between the press plates 1a and 1b,
Before the ejection of high-pressure steam is started, the vacuum pump VP (or blower) is operated to evacuate the pores 3b formed in the lower press platen 1b to reduce the pressure in the sealed space. After that, the valve may be closed and the vacuum pump VP (or the blower) may be stopped so that the high-pressure steam is jetted into the sealed space in the depressurized state. In this case, leakage of the high-pressure steam to the outside can be prevented more reliably, waste of the high-pressure steam can be surely eliminated, and the safety of the surroundings can be further compensated.

FIG. 2 shows another example of the apparatus for carrying out the method for stabilizing the dimension of wood material according to the present invention. This example is a suitable example when a flat plate press in which the press plate is not provided with pores communicating with the outside is used in the processing method of the present invention, and is a flat plate-shaped first having pores 23a for jetting steam. The separate member 20a is fixed to the upper press platen 1a with the screw 21a, and the second plate-like second separate member 20b having the pores 23b for vacuuming is further installed with the screw 21b. It is fixed to. Each of the pores 23a and 23b is connected to the high-pressure steam generation source S and the vacuum pump VP, as in the case of the device shown in FIG. The method of using this device is substantially the same as in the case of FIG.

FIG. 3 shows still another example of an apparatus for carrying out the method for stabilizing the dimension of wood material according to the present invention. This device is different from the device shown in FIG.
b is a bottomed box-shaped pressure-resistant container having an open space 35 whose upper side is open, and a packing 36 is attached to the upper end surface of the second separate member 30b. . This device has an advantage that the sealed space can be easily formed between the press plates without separately disposing the thickness regulating jig 10 and the sealing material.

FIG. 4 shows still another example of the apparatus for carrying out the method for stabilizing the dimension of wood material according to the present invention. Compared with the device shown in FIG. 2, the second separate member 30b is a bottomed box-shaped pressure-resistant container having an open space 35 whose upper side is open, and the first separate member 30a is open. The difference is that it has an insertion convex portion 31a having a cross-sectional shape that is substantially the same as the cross-sectional shape of the space 35, and the pores 33a reach the tip end surface of the insertion convex portion 31a. A packing 36 is attached around the convex portion 31a of the first separate member 30a. With this device, a sealed space can be easily formed between the press plates, and at the same time, the press plates 1a, 1b can be formed.
By adjusting the distance of the wood material W of different thickness
Also, there is an advantage that dimensional stabilization processing can be performed.

[0027]

EXAMPLES The present invention will be described below based on examples. Example 1 Using the press plates shown in FIG. 1, pores of 2 mmφ were formed vertically and horizontally at 40 mm intervals on the surfaces of both press plates. The pore group of the upper press platen was connected to a high-pressure steam generation source, and the pore group of the lower press platen was connected to a vacuum pump.
15 mm thick M type particle board 3 as a processing material
0 cm × 30 cm was used, and it was placed on the group of pores formed on the lower press platen. Furthermore, aluminum plates with a height of 15 mm are placed on both sides as thickness control jigs, and 50 kg
It was clamped with a press pressure of f / cm ² . Next, while operating a vacuum pump continuous with the group of pores formed on the lower press platen, 10 kgf / c from the group of pores formed on the upper press platen
m ² of saturated steam (180 ° C.) was spouted for 10 minutes.
After the vacuum pump was stopped and the supply of steam was also stopped, the pressure was released and the treated wood material was taken out (Product 1).

Example 2 Saturated water vapor pressure was set to 15 kgf /
A treated wood material was obtained in the same manner as in Example 1 except that it was changed to cm ² (200 ° C.) (Product 2).

[Comparative Example 1-1] The same wood material as in Example 1 was pressed in the same manner as in Example 1, and then saturated steam of 10 kgf / cm ² was formed from the group of pores formed in both the upper and lower press plates. (180 ° C.) was spouted for 10 minutes. After that, the pressure was released and the treated wood material was taken out (Comparative Product 1-1). [Comparative Example 1-2] A treated wood material was obtained in the same manner as in Comparative Example 1-1 except that saturated steam was jetted for 20 minutes (Comparative Product 1-2).

[Embodiment 3] After being pressed in the same manner as in Embodiment 1 except that a 3 mm thick M type MDF 30 cm × 30 cm is used as a wood material and an aluminum plate having a height of 3 mm is arranged as a thickness regulating jig, Saturated steam (180 ° C.) of 10 kgf / cm ² was ejected for 5 minutes to obtain a treated wood material (Product 3) in the same manner as in Example 1.

[Embodiment 4] A saturated steam pressure of 15 kgf /
A treated wood material was obtained in the same manner as in Example 3 except that the product was cm ² (200 ° C.) (Product 4). [Comparative Example 2-1] The same wood material as in Example 3 was pressed in the same manner as in Example 3, and then saturated steam of 10 kgf / cm ² (1
80 ° C.) was spouted for 5 minutes. Then, the depressurized and treated wood material was taken out (Comparative Product 2-1).

[Comparative Example 2-2] A treated wood material was obtained in the same manner as in Comparative Example 2-1 except that saturated steam was jetted for 10 minutes (Comparative Product 2-2).

[Example 5] Products 1 to 4 and comparative product 1 described above
-1, 1-2, comparative products 2-1, 2-2, and Example 1
And the untreated wood materials used in (3) and (3) (Comparative products 3 and 4), the density (g / cm ² ) and the bending strength (k
gf / cm ² ), peel strength (kgf / cm ² ), cold water immersion thickness change rate (%) (according to JIS A5908 particle board: 20 ° C., 24 hours immersion), and boiling thickness change rate (%) ) (According to JIS A5908 particle board: 2 hours after boiling, 1 hour of cold water) was measured. The results are shown in Tables 1 and 2.

[0034]

[Table 1]

[0035]

[Table 2]

As shown in Tables 1 and 2, the products subjected to the dimensional stabilization treatment method according to the present invention are untreated products and high-pressure steam in both the cold water immersion thickness change rate and the boiling thickness change rate. Compared with the treated product which was treated but not evacuated, it was greatly improved, confirming the effectiveness of the present invention. Also, it can be seen that almost the same result can be obtained in a short processing time.

[Embodiment 5] A press platen capable of forming a sealed space shown in FIG. 3 is used, and both press plates are 2 mm.
Pores having a diameter were formed vertically and horizontally at intervals of 40 mm. The pore group of the upper press platen was connected to a high-pressure steam generation source, and the pore group of the lower press platen was connected to a vacuum pump. The thickness of the frame forming the sealed space was 15 mm. 15 as processing material
mm type M type particle board 30cm × 30c
m was placed on the group of pores formed on the lower press platen. Further, lower the press to 50 kgf / cm.
^It was clamped with a press pressure of ² . Next, the vacuum pump continuous with the group of pores formed on the lower press platen was operated to reduce the pressure in the sealed space to 60 mmHg. After reducing the pressure, the valve was closed and the vacuum pump was stopped. Next, from the group of pores formed on the upper press plate, saturated steam of 15 kgf / cm ² (about 2
(00 ° C.) was spouted for 10 minutes. Next, high-pressure steam was released from the sealed space, the press was decompressed, and the treated wood material was taken out (Product 5).

[Embodiment 6] As a wood material, M type MDF 30 mm × 30 mm having a thickness of 3 mm was used, and the frame body for forming a sealed space had a thickness of 3 mm. The pressure was reduced by a vacuum pump. The saturated steam to be jetted was 15 kgf / cm ² (about 200 ° C.), and the jetting time was 5 minutes. Hereinafter, a treated wood material was obtained in the same manner as in Example 5 (Product 6).

[Embodiment 7] Regarding the above-mentioned products 5 and 6,
Density (g / cm ² ), bending strength (kgf / cm ² ), peel strength (kgf / cm ² ),
Cold water immersion thickness change rate (%) (JIS A5908 particle board conforming: 20 ° C., 24 hours immersion), and boiling thickness change rate (%) (JIS A5908 particle board conforming: 2 hours after boiling, cold water 1 Time) was measured. The results are shown in Table 3.

[0040]

[Table 3]

As shown in Table 3, the products 5 and 6 also show results equal to or higher than those of the products 1 to 4 in all measurement items, and a method of ejecting high-pressure steam after depressurizing the sealed space. Was confirmed to be as effective as the other methods.

[0042]

EFFECTS OF THE INVENTION According to the dimension stabilization treatment method for wood materials,
Compared with the conventional method, it is possible to obtain a treated wood material having high dimensional stability.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an apparatus for performing a dimensional stabilization treatment method for wood materials.

FIG. 2 is a view showing another example of an apparatus for carrying out the dimension stabilization treatment method for wood materials.

FIG. 3 is a view showing still another example of an apparatus for carrying out the dimension stabilization treatment method for wood materials.

FIG. 4 is a view showing still another example of an apparatus for carrying out the dimension stabilization treatment method for wood materials.

[Explanation of symbols]

1a, 1b ... Press board, 2a, 2b ... Heater, 3a ... High pressure steam jetting pore, 3b ... Vacuum suction pore, 4a ... High pressure steam supply pipe, 5b ... Vacuum suction pipe, 10 ... Thickness regulation Jig, W ... Wood material, S ... High-pressure steam supply source, VP
…Vacuum pump

Claims (2)

(57) [Claims] 1. An internal space capable of containing a wood material.
A press board provided with a box-shaped member having
And a press board provided with a lid member for sealing the inside of the sealed space formed by the box-shaped member and the lid member.
A wood-based material, and place one of the box-shaped member and the lid member
After decompressing the sealed space by pre-evacuating via
Supply high-pressure steam toward the wood through the other member
A method for stabilizing the dimension of wood materials, which is characterized by: 2. A method according to claim 1, characterized by performing the processing while the wood material under pressure compressed between the two said press platen
A method for stabilizing the dimension of wood described in the above .