JPH1110608A - Dimensionally stabilizing method of wooden material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give a high dimensional stability at all times to a wooden material by a method wherein steam is surely permeated and uniformly supplied into the wooden material. SOLUTION: A wooden material W to be processed is pinchingly arranged in an enclosed space, which is formed between two press platens 1a and 1b and has a height equal to or slightly lower than the initial thickness of the wooden material W to be processed. Then, vacuum suction is executed from one press platen 1b side through pores 3b and a piping 4b with a vacuum pump VP so as to supply high pressure steam in the enclosed space under pressure reduced state from the other press platen 1a side through a piping 4a and pores 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dimensional stabilization of a wooden material, and more particularly to a method for processing a wooden material in which high-pressure steam is supplied into the wooden material to improve the dimensional stability of the wooden material. Method improvement.

[0002]

2. Description of the Related Art Wood swells or shrinks due to the absorption and release of moisture. This means solid sawn board, thin wood (thickness 0.2
mm to 10 mm), particle board, MDF
The same applies to (medium fiber board), OSB (oriented strand board) and the like. When a wooden material is used as a material for construction or furniture, it is not preferable that the wooden material swells or shrinks depending on the environment, and it is desired that the wooden material has dimensional stability that is not affected by the environment.

[0003] As a countermeasure, a method has been used in which a wooden material is sandwiched up and down by a press machine, placed in an autoclave, and treated with high-pressure steam for several minutes to stabilize the dimensions of the wooden material. However, in this method, in addition to the large-scale equipment, it is difficult to infiltrate the high-pressure steam into the wood material (central portion), and the treatment state in the central portion and the peripheral portion of the wood material may be different.

[0004] The present applicant has conducted many experiments and studies in order to eliminate the inconvenience, and arranged wood materials to be processed between hot plates of a flat press having a hot plate used in conventional wood processing. In addition, an elastic sealing material such as an elastic silicon material around the surroundings, and a thickness-regulating jig made of a material such as a stainless steel surrounding the same, with a height equal to or slightly lower than the thickness of the wooden material to be treated. A certain thickness regulating jig is arranged and sealed by moving the press plate to form a sealed space, and high-pressure steam is supplied from the steam supply holes provided in the upper and lower hot plates into the sealed space to thereby provide high-pressure steam. A method for stabilizing the size of a wooden material has been proposed (JP-A-6-238616).

[0005] The above-mentioned processing method can be performed by using a flat plate press having a normal hot plate used for pressing wood and manufacturing composite materials, and dimensional stabilization processing of wood materials is simplified. . Furthermore, the dimensional stabilization treatment of wood using high-pressure steam can be performed without using chemicals such as phenol and formalin. It is also useful from a certain point.

[0006]

In the process of stabilizing the dimensions of a wooden material by the above-described processing method, the present inventors have determined that the specific gravity, thickness, size, surface condition, etc. of the wooden material may vary. However, they experienced that high-pressure steam was not uniformly supplied to the interior of the wood material, and as a result, the desired dimensional stability was not achieved.

[0007] In the case of a flat wooden material, high-pressure steam can easily penetrate from the front end of the wood as compared with the front and back surfaces.
In the conventional dimensional stabilization method, high-pressure steam is supplied from the upper and lower press boards, and as a result, high-pressure steam enters the interior of the wood material mainly from the front and back sides of the wood material. Therefore, it takes a long time for the high-pressure steam to enter the wood material. High energy is required to obtain high-pressure steam (saturated steam or superheated steam), and it is desired that the required amount of high-pressure steam be as small as possible so as not to increase processing costs.

A wood material having a water content of at least about 8 to 10% and a temperature of about 15 to 25 ° C. at normal temperature and normal state is directly placed in a sealed space formed between hot plate presses or the like. In this case, the temperature of the wood is raised to a temperature at which the water contained in the wood becomes steam, and the energy of the high-pressure steam produced at high cost is used to convert the water into high-pressure steam. This means that there is a loss in terms of processing time and energy. In addition, when the wood material to be treated is a plate material made of natural wood such as a solid ground plate or a thin wood plate, it is difficult for internal moisture to emanate as described above, and high-pressure steam does not easily enter. ,
Processing takes time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to facilitate the intrusion of high-pressure steam supplied from the outside into the interior of a wooden material, thereby enabling high-pressure steam treatment. An object is to reduce the processing cost by shortening the required time.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for storing a wooden material in a sealed space, depressurizing the sealed space, and then applying high pressure to the depressurized sealed space. A method for dimensional stabilization of a wooden material, in which steam is introduced to stabilize the size of the wooden material by high-pressure steam treatment, wherein the wooden material is sandwiched between upper and lower surfaces constituting a sealed space, and The reduced pressure in the sealed space is obtained by evacuation from one or both sides of the upper and lower surfaces of the sealed space, or by evacuation from the side surfaces of the sealed space, or one or both of the side surfaces and the upper and lower surfaces of the sealed space. Is performed by evacuation from the side of.

In the present invention, the supply of the high-pressure steam into the sealed space may be performed from any position and in any manner as long as the depressurized state of the sealed space is established. For example, it may be performed by jetting from any one of the side surface, the upper surface, or the lower surface of the sealed space, or a combination of any of those surfaces. It is performed by evacuation from one side, and after evacuation is established, evacuation is stopped, and high-pressure steam is applied from the other side of the upper and lower surfaces of the sealed space and, if necessary, from the side surface of the sealed space. May be supplied.

Further, after the supply of the high-pressure steam is started, the evacuation of the sealed space may be stopped, and the evacuation of the sealed space may be continuously performed in parallel with the supply of the high-pressure steam. .

In the present invention, there is no particular limitation on the wood material to be treated, and not only wood materials such as solid ground boards and wood veneers, but also wood processing materials such as MDF, OSB and particle board. Can also be processed. It is particularly effective to perform the treatment of the present invention while applying pressure and compression by a press plate to a plate made of natural wood.

In the present invention, the hermetically sealed space is preferably formed between press plates of a flat press conventionally used for pressing wood or manufacturing a composite material, but is not limited thereto. In the case of using a press board, the press board may or may not have a heat source. When the press board has a large number of pores communicating with the outside, connect the pores of one press board to a conventionally known high-pressure steam generation source via appropriate piping and valve means, The other press plate is connected to a well-known, preferably heat-resistant vacuum pump such as a vacuum pump through a suitable pipe and valve means. Preferably, a suction blower is arranged on the piping on the vacuum side. Thereby, it becomes possible to evacuate the inside of the sealed space accommodating the wood material through the press board to reduce the pressure and to supply high-pressure steam. One or both pores of the upper and lower press boards are switchably connected to a vacuum source and a high-pressure steam source, and vacuum is performed from one or both of the upper and lower press boards, and when a predetermined depressurized state is reached. Alternatively, the pressure may be switched from the vacuum source to the high-pressure steam source, and high-pressure steam may be supplied from one or both of the upper and lower press boards.

As another method for supplying and evacuation of water vapor, a large number of pores are formed between upper and lower press boards and wood material on upper and lower surfaces and, if necessary, on side surfaces, and are pressure-resistant and heat-resistant. You may make it arrange | position another member which has a property, and may perform it.
In this case, the pores formed in the separate member are formed in the same manner as the pores formed in the press platen, and the steam generation source and / or
Alternatively, connect to a vacuum source. Thereby, it is possible to reduce the pressure in the sealed space and supply high-pressure steam through the pores of the separate member. A preferred embodiment of this kind of separate member comprises 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 the present invention, the wood material to be treated is placed and clamped in a sealed space having a height equal to or slightly less than its initial thickness. That is, in the present invention, the term “clamped” includes not only a clamped state in a non-compressed state but also a mode clamped while being pressed and compressed.
Due to the sandwiching, the surface of the wooden material and the upper and lower surfaces of the sealed space are brought into close contact with each other, and the intrusion of the jetted high-pressure steam into the wooden material is ensured.

A mesh having a small mesh, for example, a wire mesh,
It is also possible to carry out the above-mentioned treatment in a state where it is arranged on the upper or lower surface or any surface of the wooden material, or is attached to both or any surface on the upper and lower inner surfaces of the sealed space. Is ensured,
It is possible to perform uniform processing in a short time.

In a preferred embodiment in which a sealed space is formed between two press plates, a thickness regulating jig having a height equal to or slightly lower than the initial thickness is arranged around the wooden material. The material of the thickness regulating jig may be a member having the required rigidity and heat resistance, and an aluminum material, a stainless steel material or the like is preferably used. As described above, when a member including a box-shaped member and a lid member is used as another member, the thickness (height) of the member itself is used.
It is possible to form a sealed space in which the thickness is regulated, and it is not always necessary to use a thickness regulating jig. In this case, for example, the distance between the upper and lower press plates is measured, and a means for controlling the movement distance of the press plate to a desired distance based on the measured value is equal to or slightly lower than the initial thickness of the wooden material. It is possible to form a sealed space with a height inside.

When a thickness regulating jig is arranged, many pores are formed on the inner surface side of the thickness regulating jig, and the pores are connected to a high-pressure steam generation source and / or a vacuum source. You may do so. In this case, it becomes possible to evacuate and / or supply high-pressure steam from the side surface of the thickness-regulating jig, so that the dimensional stabilization method is further homogenized and speeded up.

When a sealed space is formed between two press boards, it is effective to arrange an elastic sealing material having a height higher than the thickness regulating jig together with the thickness regulating jig. As the elastic sealing material, any material can be used as long as it has a sealing function of not leaking 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, preferably, the thickness regulating jig is arranged outside the elastic sealing material.

When a sealed space is formed between two press plates, the press plate is heated to a temperature slightly higher than the high-pressure steam to be supplied by a heat source, if necessary. And the wooden material is accommodated between two press boards (or separate members). Thereby,
The sealed space is in a high temperature state, and the heat loss of high-pressure steam supplied later can be reduced. In that state, evacuation is started, and preferably, when the pressure is reduced to about 60 to 750 mmHg, saturated steam or superheated steam (steam having a higher temperature than saturated steam) is jetted into the sealed space. At this point, the evacuation means such as a vacuum pump may be stopped, or the high-pressure steam may be supplied while evacuation is continued without stopping. In any case, since the sealed space is in a decompressed state, the high-pressure steam jetted from the pores toward the wood material enters the wood material from the surface and surroundings of the wood material in a short time, Distribute equally and evenly. As a result, the dimensional stabilization process proceeds quickly over the entire area. In addition, release of high-pressure steam to the outside is suppressed, and loss of steam can be eliminated.
After a predetermined amount of high-pressure steam has been supplied to the sealed space which has been reduced in pressure as described above, and preferably has been set in a heated state, high-pressure steam may be supplied while evacuating again. In this case, it is possible to use the high-pressure steam effectively and to speed up the processing.

The optimum treatment conditions are determined experimentally according to 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.

Immediately after the end of the predetermined high-pressure steam ejection, the high-pressure steam may be released to the atmosphere and decompressed.
After leaving for a predetermined time for a while, the high-pressure steam may be released to the atmosphere to release the pressure. 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 a hot platen. According to the experiment, the dimensional change rate of the obtained final product was smaller when the decompression was performed in the cold state than when the decompression was performed gradually, and the surface state was smoother.

As the wood material to be subjected to the high-pressure steam treatment, a wood material which has been heated in advance and has a lower moisture content than a naturally dried state may be used. In this case, the time required for the wooden material to heat up to the temperature at which the high-pressure steam treatment starts can be shortened, and the amount of energy of the supplied high-pressure steam required to convert the water content of the wooden material into steam can be reduced. Thereby, energy loss in the high-pressure steam processing is avoided, and the time required for the dimensional stabilization processing in the sealed space is also reduced.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows an example of an apparatus for carrying out a method for stabilizing the size of wood material according to the present invention. In the figure, reference numerals 1a and 1b denote press plates similar to those mounted on a flat plate press used in conventional wood processing, each of which is provided with heaters 2a and 2b as a heat source, and further, a large number of heaters are provided on the surface portion. Pores 3a, 3b are formed. The pores 3a formed in the upper press platen 1a are pipes 4
a and the on-off valve V are connected to the high-pressure steam generation source S, and the fine holes 3b formed in the lower press platen 1b are connected to the vacuum pump VP via the pipe 4b. A blower (not shown in FIG. 1) may be used instead of the vacuum pump. Further, a thickness regulating jig 10 having a height equal to or slightly lower than the initial thickness of the wooden material W to be processed is attached to the upper press platen 1a by appropriate fixing means (not shown). Reference numeral 11 denotes an elastic packing provided on the upper edge and the lower edge of the thickness regulating jig 10 to maintain the sealing.

In carrying out the treatment method according to the present invention using this apparatus, first, a flat wooden material W as a treatment material is placed on a lower press platen 1b, preferably with pores 3b.
Is placed at the position where is formed, and then the press platen 1a,
1b is approached and stopped until it is regulated by the thickness regulating jig 10. As a result, the wood material W is placed on the upper press platen 1
a and the lower press plate 1b is housed in a sealed space in the thickness regulating jig 10 in a posture sandwiched between both surfaces of the lower press plate 1b. As described above, an elastic sealing material (not shown) may be arranged around the wooden material W to increase the degree of sealing between the press plates 1a and 1b.

In this state, the vacuum pump VP (or blower) is operated to evacuate the small holes 3b formed in the lower press platen 1b, thereby reducing the pressure in the sealed space. When a predetermined reduced pressure is obtained, stop evacuation,
The on-off valve V provided on the pipe 4a on the side of the high-pressure steam generation source S is opened, and high-pressure steam is ejected from the fine holes 3a formed in the press platen 1a. Thereby, the jetted steam easily and uniformly reaches the interior of the wood material W. Further, since the evacuation is performed, the high-pressure steam does not leak to the outside, eliminating waste of the high-pressure steam and compensating for the surrounding safety.

After the jetting of the desired amount of high-pressure steam,
Thereafter, the decompression and cooling steps by releasing high-pressure steam to the atmosphere are performed in the same manner as in the case of the conventional method, whereby the method for stabilizing the size of wood material according to the present invention is completed.

FIG. 2 shows another example of an apparatus for carrying out the method for stabilizing the size of woody material according to the present invention. This example is a preferred example in the case where a flat plate press in which a press plate is not provided with pores communicating with the outside is used in the processing method of the present invention, and a flat plate-like first plate having pores 23a for steam ejection is used. Is fixed to the upper press platen 1a using screws 21a, and a flat plate-like second separate member 20b having pores 23b for evacuation is formed using the screws 21b. It is fixed to. Each of the pores 23a and 23b is connected to a high-pressure steam generation source S and a vacuum pump VP, as in the case of the apparatus shown in FIG.

Further, the plate-shaped first separate member 20a has a height equal to or slightly lower than the initial thickness of the wooden material W to be treated, and elastic packings 11 on the upper and lower edges. The holding thickness control jig 10 is attached by an appropriate fixing means. The thickness regulating jig 10 has a large number of pores 10a formed on the inner peripheral surface side.
The pores 10a are connected to a high-pressure steam generation source S via a pipe 4a. The method of using this device is substantially the same as that of FIG.
Is supplied also from the pores 10a located in the vicinity of the side surface of the wood material W formed on the inner peripheral surface of the wood material W, so that the high-pressure steam supplied therefrom easily enters the inside of the wood material W from the tip of the wood. And a uniform and rapid high-pressure steam treatment proceeds.

FIG. 3 shows still another example of an apparatus for carrying out the method for stabilizing the size of wood according to the present invention. This device is a bottomed box-shaped pressure-resistant container having an open space 35 in which a second separate member 30b is open on the upper side, and the depth of the open space 35 is equal to the depth of the wooden material W to be treated. It is assumed to be almost equal to or slightly shallower at the beginning. Further, a large number of pores 33c are formed on the inner peripheral surface side of the open space 35, and the pores 33c are connected to the vacuum pump V via a pipe 4b.
Connected to P. A packing 36 is attached to the upper end surface of the second separate member 30b. In this device, a sealed space can be easily formed between the press plates without separately arranging the thickness regulating jig 10 and the sealing material. Since the evacuation is also performed from the pores 33c opened on the peripheral surface side, there is an advantage that the pressure in the sealed space can be quickly reduced.

FIG. 4 shows still another example of the apparatus for performing the method for stabilizing the size of wood material according to the present invention. Compared to the apparatus shown in FIG. 2, the second separate member 30b is a box-shaped pressure-resistant container having an open space 35 with an open upper side, and the first separate member 30a It is different in that it has an insertion protrusion 31a having a cross section substantially the same as the cross section of the space 35, and the pore 33a reaches the tip end surface of the insertion protrusion 31a. Then, a packing 36 is attached around the projection 31a of the first separate member 30a. In this apparatus, a sealed space can be easily formed between the press plates, and the wood materials W having different thicknesses can be easily adjusted by adjusting the distance between the press plates 1a and 1b. It becomes possible to pinch.

FIG. 5 shows still another example of an apparatus for carrying out the method for stabilizing the size of wood according to the present invention. In this example, a mesh made of a material having heat resistance and pressure resistance such as a wire mesh is fixedly attached to the surfaces of the press plates 1a and 1b. Due to the presence of the reticulated body, the evacuation between the surface of the wood material and the surfaces of the press plates 1a and 1b becomes easy,
Further, the dispersion of the supplied high-pressure steam is improved, and uniform processing can be performed in a short time. Instead of attaching the net-like body 61 to the press plates 1a and 1b, it may be simply disposed on the lower press plate 1b or on the upper surface of the wooden material W so as to be freely detachable.

Although not shown, the pores 10a formed on the inner surface side of the thickness regulating jig 10 may be connected to a vacuum evacuation source VP, and the side of the thickness regulating jig may be evacuated. This may be performed independently, or may be performed in parallel with evacuation from the upper and lower press boards 1a and 1b. Further, in the case of the apparatus shown in FIG. 3, it is also possible to connect the pore 33c formed on the inner side surface of the second separate member 30b to the high-pressure steam generation source S and supply the high-pressure steam from the side surface. is there. Further, although not shown, also in the case of the apparatus shown in FIG. 4, a large number of pores are formed on the inner side surface of the second separate member 30b, and the pores are formed in the vacuum source VP and / or the high-pressure steam source S. It is also possible to connect and supply vacuum and / or high pressure steam from its side.

[0035]

According to the method for stabilizing the size of wood,
Compared with the conventional method, it is possible to obtain a processed wood material having high dimensional stability in a short processing time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an apparatus for performing a method for stabilizing a size of a wooden material.

FIG. 2 is a diagram showing another example of an apparatus for performing a method for stabilizing the size of a wooden material.

FIG. 3 is a diagram showing still another example of an apparatus for performing the method for stabilizing the size of a wooden material.

FIG. 4 is a view showing still another example of the apparatus for performing the method for stabilizing the size of a wooden material.

FIG. 5 is a diagram showing still another example of the apparatus for performing the method for stabilizing the size of a wooden material.

[Explanation of symbols]

1a, 1b: press board, 2a, 2b: heater, 3a: high-pressure steam jetting pore, 3b: vacuum evacuation pore, 4a: high-pressure steam supply pipe, 5b: vacuum evacuation pipe, 10: thickness regulation Jig, W: wood material, S: high-pressure steam supply source, VP
…Vacuum pump

Claims (9)

[Claims] 1. A wooden material is accommodated in a sealed space, and after reducing the pressure in the sealed space, high-pressure steam is introduced into the reduced-pressure sealed space to stabilize the dimensions of the wooden material by high-pressure steam treatment. A method for stabilizing a size of a wooden material, wherein the wooden material is sandwiched between upper and lower surfaces constituting a sealed space, and a reduced pressure in the sealed space is reduced by one or both of upper and lower surfaces of the sealed space. A method for stabilizing the size of a wooden material, wherein the method is carried out by evacuation from wood. 2. A wooden material is accommodated in a sealed space, and after reducing the pressure in the sealed space, high-pressure steam is introduced into the reduced-pressure sealed space to stabilize the dimensions of the wooden material by high-pressure steam treatment. A method for stabilizing the size of a wooden material, wherein the wooden material is sandwiched between upper and lower surfaces constituting a sealed space, and the pressure in the sealed space is reduced by evacuation from a side surface of the sealed space. A method for stabilizing the size of a wooden material, characterized in that: 3. A wooden material is accommodated in a sealed space, and after reducing the pressure in the sealed space, high-pressure steam is introduced into the reduced-pressure sealed space to stabilize the dimensions of the wooden material by high-pressure steam treatment. A method for stabilizing the size of a wooden material, wherein the wooden material is sandwiched between upper and lower surfaces constituting a sealed space, and the pressure in the sealed space is reduced by one or more of the side surface and the upper and lower surfaces of the sealed space. A dimensional stabilization method for wooden materials, wherein the method is performed by vacuuming from both sides. 4. The method according to claim 1, wherein the supply of high-pressure steam into the sealed space is performed by jetting high-pressure steam from the side surface and / or the upper surface and / or the lower surface of the sealed space. Dimensional stabilization method for woody materials described above. 5. A wooden material is accommodated in a sealed space, and after reducing the pressure in the sealed space, high-pressure steam is introduced into the reduced-pressure sealed space to stabilize the dimensions of the wooden material by high-pressure steam treatment. A method for stabilizing a size of a wooden material, wherein the wooden material is sandwiched between upper and lower surfaces constituting a sealed space, and a reduced pressure in the sealed space is reduced by vacuum from one of upper and lower surfaces of the sealed space. The high pressure steam is supplied from the other side of the upper and lower surfaces of the sealed space, and further, the evacuation and the supply of high pressure steam are performed from the side surface of the sealed space. Dimension stabilization processing method for wood materials. 6. The dimensional stabilization method for woody material according to claim 1, wherein the inside of the sealed space is evacuated in parallel with the supply of the high-pressure steam. 7. The sealed space is a sealed space formed between upper and lower press boards.
Any one of the above-described methods for stabilizing wood materials. 8. A separate member for forming a sealed space, supplying high-pressure steam, and evacuating between the press board and the wooden material, and supplying and evacuating high-pressure steam via the separate member. 8. The method for stabilizing the size of wood material according to claim 7, wherein: 9. A wooden material is sandwiched between a surface of the wooden material and an inner surface of the sealed space in a state where a mesh is interposed therebetween, and in this state, the pressure in the sealed space is reduced and the pressure in the sealed space is reduced. The method for stabilizing the size of wood material according to any one of claims 1 to 8, wherein steam is supplied.