JP6561285B2 - Wood processing methods and processed products - Google Patents

Description

  The present invention relates to a processing method and a processed product for suppressing deformation such as warpage that occurs over time for wood, in particular, solid plate material, strip-shaped wood, or wood that has been subjected to decorative processing, and decorative processing on the processed product. It relates to the processed product.

Wood, especially wood that has been processed into a plate or strip shape, has been deteriorated over time due to a decrease in moisture content due to a decrease in moisture content, and due to changes in the state and amount of substances constituting the wood. Deformation (this is hereinafter referred to as temporal deformation) has been a problem. For this reason, when using wood, the moisture content of the wood exceeding 100% before drying is reduced to less than 15%, or the wood is dried while inverting the front and back every day for a period of about one year, Such processing is performed.
However, even with wood with a reduced moisture content, the shape may change due to further drying or moisture absorption / drying due to seasonal changes in humidity and temperature, resulting in poor dimensional accuracy. It was a problem. In particular, when precision processing such as laser processing or printing is performed on wood, there has been a problem that a shift due to temporal deformation of the wood occurs in these processing to a selected location.
This time-dependent deformation is complicated in form due to the amount and shape of the canal contained in the wood, the amount of lignin and hemicellulose that connect the canal and the temporary canal (hereinafter referred to as the canal), etc. It was difficult to predict and could not be controlled. Here, the canal is a main component in the xylem tissue of angiosperms.
For this reason, when various types of processing are performed on wood, it is difficult to handle such as surface processing that expresses the desired design due to dimensional errors, and it is also a product of surface processing that never looks beautiful. It was an issue on. Further, when laser processing or the like is performed, there is a problem that the wood is further deformed after the processing.

In order to solve such a problem, for example, in Patent Document 1, wood is placed in a sealed atmosphere in order to remove the internal stress of the wood, and the temperature of the sealed atmosphere is raised to a uniform state at a predetermined temperature and humidity. It describes a method and apparatus characterized in that after maintaining for a predetermined time, the wood is taken out from the sealed atmosphere, sprayed with hot water at a predetermined temperature, and further dried until the moisture content of the wood decreases to a predetermined value.

Further, Patent Document 2 holds water vapor at 60 ° C. to 150 ° C. in a state close to hermetically sealed for a certain period of time, lowers the softening point of lignin and hemicellulose, which are the main components of wood, and further reduces the wood structure by internal stress of wood. A method for reducing the internal stress of wood is described in which cells are flowed and moisture in the wood is evaporated.

On the other hand, Non-Patent Document 1 shows that many wooden buildings exist in Japan, including Horyuji five-storied pagoda and Shokurain Masakura, and wood is a long-life material on the order of 1000 years. However, although there is not much change in the strength of the wood in the fiber direction (the direction of the canal), it has been shown that the strength in the radial direction decreases with time and that deformation such as warpage does not occur. As the cause, it has been shown that quantitative and qualitative changes such as lignin and hemicellulose have occurred.

Japanese Patent No. 2757170 JP-A-8-267414

Osamu Yokoyama, Journal of Materials Life Society, 27, 39-40 pages, 2015

In the method described in Patent Document 1, since all parts of the wood are uniformly treated, it has been a problem that the processing of selecting a place to be treated on the wood surface in a complicated state cannot be performed.
In addition, since a process such as spraying hot water is required, there has been a problem in terms of cost such as installation of a large and complicated apparatus. Furthermore, the heating temperature of wood requires heating in the range of 90 ° C. to 120 ° C., or heating time of 60 hours or more is required, and this is easily performed in terms of cost, time, equipment, etc. It was difficult.

Further, as described in Patent Document 2, in the treatment method using water vapor, the internal pressure in the treatment tank becomes high, so that the wood can be placed inside, and the pressure exceeding 1 atm is maintained. Since a sealing device that can be used is necessary, it has been difficult to secure cost and equipment, and safety during work.

For these reasons, a relatively easy method, a short processing time, a method for removing internal stress that can be performed at a relatively low temperature and limiting and selecting the parts of the wood to be processed, and processed wood products that have undergone such processing Was strongly desired.

In addition, as described in Non-Patent Document 1, it can be used for a long period of time as a building material for buildings, that is, a method of treating so that the internal stress of the wood is removed and the wood is used for a long time. Development was desired. In addition, it has been desired to develop a method for treating wood, which has an effect of improving the sound absorbing performance expressed by the increase in the surface area per unit weight of the wood surface and the deodorizing effect by adsorption.

As a result of intensive studies to solve the above problems, the present inventors have been able to realize a quantitative and qualitative change such as lignin and hemicellulose, which has been reported in wood used for a long time, in a short time. We thought that it was possible to reduce the deformation over time, which was a problem in the use of.

The inventors contact protease solution, galactanase, cellulase, pectinase, xylanase, and an aqueous solution containing at least one enzyme from hemicellulase containing these in combination with part or all of the wood, and The present invention has been accomplished by developing a method for treating wood, which selectively decomposes lignin and hemicellulose present at the location to reduce the internal stress present in the wood and is less likely to cause shape deformation over time.

That is, the present invention is a method for removing internal stress of wood, a contact step of contacting an aqueous enzyme solution with a part or all of wood having a moisture content of 1% or more and 60% or less, a substance constituting the wood, and the enzyme It is the internal stress removal method for reducing the time-dependent deformation | transformation of the timber including the process process which reacts and a drying process.
In the contacting step of contacting wood with the enzyme aqueous solution, 0.05 weight of at least one enzyme from protease, galactanase, cellulase, pectinase, xylanase, and hemicellulase containing these in combination as enzymes contained in the enzyme aqueous solution. It is a step of bringing the aqueous solution adjusted to pH 2 or more and pH 11 or less containing from 15% to 15% by weight into contact with wood.
As the contact method on wood, a method of immersing the timber in an aqueous enzyme solution, a method of spraying the aqueous enzyme solution onto the surface of the timber, a method of applying by brush or brush the surface of the wood, the analysis of the pictures in the wood surface and a side surface The location selected from the results is contacted by at least one contact method selected from a method of treating with an aqueous enzyme solution using a printing technique. When this contact step is performed, a portion where the treatment is not performed can be selected by masking the wood before contacting the aqueous enzyme solution.
Processing steps after the contacting step, a reaction step of reacting the enzyme material constituting the timber such as lignin and hemicellulose, the timber contacting the aqueous enzyme solution to 80 ° C. below the ambient temperature 20 ° C. or higher in that state Let stand for not less than 0.5 hours and not more than 24 hours.
The drying process performed after the treatment process includes natural drying and drying using a thermostatic bath, drying using a dryer, drying while heating with a hot press, and heating after drying. A method of performing and drying is preferably used. The moisture content of the wood dried by the drying process can be confirmed by a moisture content meter or the like, and it is preferably less than 60% when using wood.
When Furthermore the process to the inside of the timber, timber contacting step of contacting the aqueous enzyme solution is keeping the temperature of the temperature and timber of the enzyme solution below 20 ° C. lower than the processing temperature of the enzyme, the enzyme solution until the internal timber After the infiltration, the reaction can be carried out at a predetermined temperature of the wood.

The present invention includes a contact process in which wood, in particular, a solid plate material, a strip-shaped wood, or a decorated wood is brought into contact with an enzyme aqueous solution, a treatment process in which a substance constituting the wood and an enzyme are reacted, and a drying process. The present invention relates to a processed product obtained by applying at least one decorative process from laser processing, cutting processing, dyeing processing, and printing processing to wood whose deformation with time has been reduced by an internal stress removing method including.

Furthermore, the present invention provides a contact step of contacting wood with an enzyme aqueous solution after performing at least one processing selected from laser processing, cutting processing, dyeing processing, and printing processing, and a substance constituting the wood and an enzyme . It is the manufacturing method of the processed wood product which removes internal stress by the internal stress removal method including the process process made to react and the drying process.

According to the wood processing method of the present invention, the internal stress of wood can be reduced. By reducing this internal stress, the occurrence of warpage can be reduced. For this reason, it is possible to use a solid plate material as a material, to use it as a composite material in which a solid plate material is combined, or to reduce warpage even in wood where warpage has occurred. Furthermore, since the internal stress is reduced, it becomes easy to perform bending as a processed product. Further, after removing the internal stress of the wood, it is possible to create a processed wood product that has been subjected to at least one processing selected from laser processing, cutting processing, dyeing processing, and printing processing. Further, after performing at least one process selected from laser processing, cutting, dyeing, and printing, the wood can be treated by the internal stress removal method of the wood to remove the internal stress.

It is an external view of the wood surface before warping generate | occur | produces. It is an external view of the wood surface where curvature generate | occur | produced. It is a side surface conceptual diagram of the measurement of the curvature rate of wood. It is an electron micrograph of the wood processed in Example 1 of this invention. 2 is an electron micrograph of wood treated in Comparative Example 1. It is a figure of the curvature improvement rate with respect to evaluation by an enzyme solution performed in Experimental example 2. FIG.

Hereinafter, the present invention will be described in more detail. The method and apparatus for wood pretreatment are not particularly limited. However, a method of natural drying, a method of drying using a thermostatic bath capable of controlling temperature and humidity, and a dryer. A method of drying using a silica gel or a method of drying using a desiccant such as silica gel is preferably used.
The method for measuring the moisture content of the wood after pretreatment can be confirmed by measuring with a moisture meter or by measuring the change in weight per unit volume by deriving the volume of the wood from the shape measurement of the wood.
The moisture content of the dried wood is preferably 1% to 60%, more preferably 1% to less than 50%, and even more preferably 1% to less than 40%. Effect of water content becomes liable enzyme solution penetrates into the wood in the process that it less than 60% 1% with the enzyme solution present invention can be confirmed appropriately. If the moisture content of the wood is less than 1%, time and cost are required for preliminary drying. On the other hand, if the moisture content of the wood is higher than 60%, the effect of the enzyme aqueous solution may be inhibited by moisture contained in the wood.
If the deformation of the wood cannot be confirmed after the pretreatment of the wood, processing such as laser processing, cutting processing, dyeing processing, and printing processing can be performed subsequently.

As the enzyme of the enzyme aqueous solution that can be used in the wood treatment step, at least one enzyme selected from protease, galactanase, cellulase, pectinase, xylanase, and hemicellulase containing these in combination can be used.
The amount of the enzyme in the aqueous enzyme solution is preferably 0.05% by weight or more and 15% by weight or less, more preferably 0.2% by weight or more and less than 10% by weight, and further preferably 0.3% by weight or more and less than 5% by weight.
When the enzyme amount in the enzyme aqueous solution is 0.05% by weight or more and 15% by weight or less, the permeation rate and reaction rate of the enzyme aqueous solution into the wood fall within a suitable range, so internal stress can be removed while maintaining the wood surface hardness. .
If the enzyme amount in the aqueous enzyme solution is less than 0.05% by weight, a long treatment time may be required. If the enzyme amount is higher than 15% by weight, the correlation between the enzyme amount and the effect of the treatment tends to decrease, or the wood surface hardness May tend to decrease or cost may increase.

The water used for the enzyme aqueous solution is not particularly limited, but the safety of the manufacturer or worker should be taken into consideration, and tap water, distilled water, ion-exchanged water and the like can be preferably used. Further, even if an aqueous solution containing less than 5% by weight of sodium, calcium, or potassium is used, it can be suitably treated without deteriorating the enzyme treatment effect.
In the enzyme aqueous solution, a thickener that does not impair the treatment effect of the enzyme can be used to adjust the viscosity of the aqueous solution. As the thickener, cyclodextrin is preferably used. Increase in the viscosity of the aqueous enzyme solution, in the step of applying the enzyme solution brush or the like, is particularly effective when performing a selective enzyme solution at a location for processing.
The pH of the aqueous solution is preferably 2 or more and 11 or less because an enzyme treatment effect is recognized. The enzyme can be selected in view of the type and processing capacity of the selected enzyme.

A part or all of the wood can be selected as the contact point between the wood to be treated and the enzyme aqueous solution.
Method of contacting process for wood and the aqueous enzyme solution, a method of immersing the timber in an aqueous enzyme solution, a method of spraying an aqueous enzyme solution to the wood surface, a method of applying by brush or brush to the wood surface is preferably used.
In the case of wood processed as a plate material, an annual ring appears on the surface of the plate material, but it is possible to identify a place where the warpage of the plate material is likely to occur from the annual ring. Specifically, as time-dependent deformation of the plate material, as shown in FIG. 2, the portion close to the tree skin often warps on the opposite side of the tree axial direction (side closer to the tree skin) (see FIG. 2). ). For this reason, after confirming the location of the annual rings on the surface of the wood, it is possible to effectively reduce the internal stress of the wood by applying the enzyme aqueous solution in the direction parallel to the axis at the center of the surface near the skin of the board. Become.
When the enzyme aqueous solution is applied to the wood surface with a brush or brush, it can be applied to a portion where the internal stress of the wood can be effectively reduced. The brush and brush are not particularly limited, but a resin brush or brush is preferably used. In this case, as described above, the effect of the enzyme for the enzyme solution The addition of the thickener does not easily flow from where it is treated is preferably observed in the enzyme solution.
An air brush used for painting is also preferably used. In the case of using an air brush, the aqueous enzyme solution can be applied to the treatment site using compressed air created by a compressor. At this time, selective processing can be performed by masking a portion of the wood that is not desired to be processed.

As a method of contacting the wood to be treated with the enzyme aqueous solution, after confirming the appearance of annual rings on the surface of the wood as an image, the computer program identifies the places that can be treated effectively and the places that should not be treated by a computer program, etc. With this printing technique, the enzyme aqueous solution can be applied to a desired portion of the wood.

The temperature, humidity, and time of the treatment process for reacting the enzyme aqueous solution with the wood to be treated will be described in detail.
The effect of removing internal stress is confirmed when the temperature of the treatment process is 20 ° C. or higher and 80 ° C. or lower. When the temperature is 30 ° C. or more and less than 70 ° C., the effect of removing internal stress is confirmed in a shorter time, and therefore, it is more preferably used. Since it can be performed, it is more preferably used. This temperature can be arbitrarily determined in view of the processing speed at the processing temperature of the selected enzyme and the time for easy processing.
The humidity in the treatment process is not particularly limited, but it is preferable that the wood surface is not dried, and a humidity of 50% or more and 100% or less is preferred because the transpiration of water from the aqueous enzyme solution is small and the treatment conditions are constant, and the humidity is 75%. It is more preferably 100% or less and a humidity of 80% or more and 100% or less is preferable because more stable treatment can be performed.
Regarding the pH of the aqueous enzyme solution, it is preferable because the treatment effect of the wood with the enzyme is confirmed at pH 2 or more and pH 11 or less, and it is preferably used because the treatment speed increases at pH 3 or more and pH 9 or less, and the treatment speed is further increased at pH 3 or more and pH 6 or less. Therefore, it is more preferably used.
The treatment time can be arbitrarily set in consideration of the treatment state of the wood, but the effect of removing internal stress is confirmed in 0.1 hours to 24 hours from the results of the enzyme treatment speed and experiment. Preferably, 0.2 hours or more and 20 hours or less are more preferable, and 0.3 hours or more and 12 hours or less are more preferable. If the treatment time is too short, the effect of removing the internal stress of the wood by the enzyme aqueous solution tends to be limited, and the treatment time is not particularly limited, but if the treatment time is too long, the treatment time and the internal stress removal of the wood are removed. The correlation with the effect tends to decrease.

Next, a drying process is performed on the wood treated with the enzyme aqueous solution. After the aqueous enzyme solution is washed and removed with water or hot water before the drying process, natural drying or drying using a thermostatic bath as a drying process, drying using a dryer, drying while pressing with a hot press machine A method of drying by hot pressing after drying is preferably used. The time for this drying step is not particularly limited, but the moisture content is preferably less than 60% as the dry state of the wood.

Wood processed products that have been subjected to at least one of laser processing, cutting processing, dyeing processing, and printing processing on wood whose internal stress has been reduced by the above-described processing has reduced internal stress that causes temporal deformation of wood. Therefore, the deformation of the wood due to the decoration on the surface is reduced.
Each processing method of laser processing, cutting processing, dyeing processing, and printing processing is not particularly limited, but the laser used for laser processing is at least one of YAG laser, carbon dioxide laser, YVO ₄ laser, excimer laser, and fiber laser. A laser processing machine equipped with two lasers is preferably used. For the cutting process, a machining center, a lathe, a saw, a rotary cutting machine or the like is preferably used. In the dyeing process, a liquid containing a dye or pigment or a dye or pigment can be directly brought into contact with wood for dyeing. As a method for contacting the dye or pigment, a brush, a printer, a printing machine, an air brush, or the like is preferably used. For printing, a printer or a printing machine is preferably used.

A contact process in which an enzyme aqueous solution is contacted with a processed wood product subjected to at least one process selected from laser processing, cutting processing, dyeing processing, and printing processing, a processing step in which an enzyme reacts with a material constituting the wood, and a drying step And a method for producing a processed wood product, in which the internal stress of the wood is removed by an internal stress removing method that reduces the temporal deformation of the wood.
In this manufacturing method, the contact step, the treatment step, and the drying step are at least one processing selected from laser processing, cutting processing, dyeing processing, and printing processing as an internal stress removal method based on the above-described conditions of the internal stress removal method for wood. It can be applied to processed wood products.
Each processing method of laser processing, cutting processing, dyeing processing, and printing processing is not particularly limited, but the laser used for laser processing is at least one of YAG laser, carbon dioxide laser, YVO ₄ laser, excimer laser, and fiber laser. A laser processing machine equipped with two lasers is preferably used. For the cutting process, a machining center, a lathe, a saw, a rotary cutting machine or the like is preferably used. In the dyeing process, a liquid containing a dye or pigment or a dye or pigment can be directly brought into contact with wood for dyeing. As a method for contacting the dye or pigment, a brush, a printer, a printing machine, an air brush, or the like is preferably used. For printing, a printer or a printing machine is preferably used. On the surface of wood that has been dyed or pigmented by dyeing or printing, the processing speed of some of the enzymes used in the internal stress removal method of the wood is reduced, so places where you do not want to remove the internal stress of wood or wood When the surface state is not desired to be changed, the wood surface can be protected by applying these dyes and pigments.

Since the lignin and hemicellulose constituting the wood are decomposed and removed by the treatment method of the present invention, the surface area per unit weight of the wood surface can be increased by about 60 times, and deformation with time can be reduced. It can also be used. The surface area can be measured by a specific surface area measurement test.

  EXAMPLES Hereinafter, although an experimental example, an Example, and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to the following Example.

(Experimental example 1)
First, in order to confirm the treatment effect of wood for each enzyme, an enzyme aqueous solution with adjusted pH was prepared, and wood was treated at a temperature of 10 ° C to 90 ° C. Wood was immersed in an enzyme aqueous solution. The concentration of the aqueous enzyme solution was 1% by weight with respect to the aqueous solution. As the wood, cedar wood (weight 5 g) selected from conifers and cherry wood (weight 5 g) selected from hardwoods were used as materials to be treated.
The treatment time is 5 hours, the effect is verified from the electron micrographs of the treated surface and the weight change of the wood before and after the treatment, and the temperature range, pH range and relative treatment effect in which the treatment effect of wood is confirmed. (Minimum 0, maximum 100). The treatment effect of this enzyme is shown in Table 1 for each enzyme type.

Wood was treated under conditions where the wood treatment effect was confirmed in the experimental examples.

Example 1
First, Example 1 and Comparative Example 1 of the present invention were performed as follows. As shown in FIG. 2 and FIG. 3, the cedar flat plate dried using a thermostatic bath (manufactured by Especmic Co., Ltd.) as a pre-drying (thickness 5 mm × width 100 mm × length 150 mm). After attaching one end surface to a table 6 with a positioning function and fixing it from above with a holding jig 9, the distance from the upper surface of the table at the lower end of the other end surface was measured. The length between the top surface of the table with respect to the width of 100 mm of the wood was 3.5 mm, and the warpage rate of the plate material was 3.5%. Another cedar board having the same size was selected and the warp rate was measured to confirm that it was 3.5%. These two cedar boards were used in Example 1 and Comparative Example 1. When the moisture content of the cedar board materials of Example 1 and Comparative Example 1 was measured, both were 8%.

Xylanase 1 was selected as the enzyme in the enzyme aqueous solution, and a 0.4 wt% enzyme aqueous solution was prepared using ion-exchanged water. The pH of the aqueous solution was 5.5, and the temperature was 25 ° C. The wood was immersed in this aqueous solution and allowed to stand in a constant temperature bath at a temperature of 60 ° C. for 2 hours. Then, after lightly washing with water, it was dried in a 60 ° C. constant temperature bath for 6 hours. The plate material at this time had a warpage rate of 0.5%, and 86% improved. As a result of taking an electron microscopic image of the surface at this time, it was confirmed that the connection between the pipes decreased, the fiber was unwound and the state causing the internal stress was partially eliminated (FIG. 4). The measured surface area of the timber after the treatment with a specific surface area measuring apparatus, a 0.59 m 2 / ^g, even 59-fold compared to 0.01 m 2 / ^g before the treatment was confirmed to be increased It was.
The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples. Thereafter, the entire surface of this wood was subjected to laser processing using a workstation laser processing machine, and the warpage rate measured after 1 hour and 1 week after laser processing was 0.5%, respectively. It was confirmed that no new warp was generated even by laser processing.

(Comparative Example 1)
The wood was treated in the same manner as in Example 1 except that no enzyme was added. The warpage rate of the plate material when this treatment was performed was 3.5%, and no difference in deformation size could be confirmed compared to before treatment. When an electron microscopic photograph of the surface at this time was performed, it was confirmed that the joints between the ducts remained as they were (FIG. 5). At this time, the warp rate of the wood was 3.5%, and the effect of improving the warp by this treatment was not confirmed.
Thereafter, the entire surface of the wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured 1 hour and 1 week after laser processing were 3.5% and 4.5%, respectively. The occurrence of a new warp was confirmed by laser processing.

From Example 1 and Comparative Example 1 above, the effect of removing internal stress of wood by the enzyme aqueous solution of the present invention and the effect of suppressing the occurrence of new warpage by laser processing on wood from which internal stress was removed were confirmed.

Next, Example 2 and Comparative Example 2 of the present invention were performed as follows. With respect to the cedar flat plate (thickness 5 mm × width 100 mm × length 150 mm) which has been subjected to preliminary drying, as shown in FIGS. Then, the distance from the lower surface of the other end surface to the upper surface of the table was measured. The length between the upper surface of the table with respect to the width of 100 mm was 2.0 mm, and the warpage rate of this plate material was 2.0%. A cedar board having the same dimensions was selected and the warpage rate was measured and found to be 2.0%. These two cedar boards were used in Example 2 and Comparative Example 2, respectively. When the moisture content of the cedar board materials of Example 2 and Comparative Example 2 was measured, both were 8%.

(Example 2)
Xinalase 1 was selected as the enzyme in the enzyme aqueous solution, and a 0.4 wt% enzyme aqueous solution was prepared using ion-exchanged water (pH 4.0). Wood was immersed in this aqueous solution, allowed to stand in a thermostatic bath at a temperature of 60 ° C. for 2 hours, then lightly washed with water, and then dried in a thermostatic bath at 60 ° C. for 3 hours. When the warpage rate of this wood was measured, it was 0.5%, and the warpage rate was improved by 75% or more. Further, the evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples. Thereafter, press drying was performed at 60 ° C. for 2 minutes using a heat press machine (MP-WCL manufactured by Toyo Seiki Co., Ltd.). The board material at this time had a warpage rate of 0.2% or less. From this result, it was confirmed that the warping was further improved by press working.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.2% or less, respectively. It was confirmed that no warping occurred.

(Comparative Example 2)
The wood was treated in the same manner as in Example 2 except that no enzyme was added. The plate material after the treatment with water had a warpage rate of 2.0%, and no change could be confirmed in comparison with that before the treatment. When an electron micrograph of the surface at this time was performed, it was confirmed that the joined state of the pipes remained as it was. From this result, the improvement effect of the curvature under this condition was not confirmed.
The wood was dried for 3 hours in a thermostatic bath at 60 ° C. and then press dried at 60 ° C. for 2 minutes with a hot press machine (MP-WCL manufactured by Toyo Seiki Co., Ltd.). The warp rate of the wood at this time was 0.5% or less, and the warp rate was improved by 75% or more.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage measured after 1 hour and 1 week after laser processing was 0.5% and 3.5%, respectively. The occurrence of a new warp was confirmed by laser processing.

(Experimental example 2)
Next, in order to confirm that the internal stress removal effect of the wood by the treatment method of the present invention is consistent with the evaluation performed in the experimental example, xylanase 1 was selected as the enzyme , the pH and the treatment temperature were controlled, and the internal stress was The removal effect was verified.
As a result of performing the test 11 times, as shown in FIG. 6, evaluation of the treatment ability obtained in the experimental example (five levels were evaluated from the result obtained from electron microscope photography and the weight change before and after the treatment of the wood) The internal stress removal effect (% improvement in warpage rate) showed a good correlation.
In addition, it was confirmed that the warpage rate was further improved when the treatment was performed with the treatment time increased under the treatment conditions where the evaluation of the example was 3 or less. Since further improvement of the warpage rate was confirmed, it was confirmed that the improvement of the warpage rate could be controlled by increasing the processing time under the same processing conditions.
From these experimental results, it was confirmed that the internal stress removal effect of the wood by the treatment method of the present invention was consistent with the evaluation performed in the experimental examples.

Examples 3 to 9 were performed as follows. For a pre-dried flat plate (thickness 5 mm × width 100 mm × length 150 mm), one end surface in the length direction was placed on the table 6 with a positioning function, and the distance from the upper surface of the table at the lower end of the other end surface was measured. . The distance from the upper surface of the table with respect to the width of 100 mm was 3.0 mm, and the warpage rate of the plate material was 3.0%.
A cedar board having the same dimensions was selected and the warpage rate was measured, and it was confirmed that the warpage rate was 3.0%. Thus, four cedar boards were selected and used in Examples 3 to 6. In Example 7, the cherry material which showed the same curvature rate% was used. When the moisture content of these cedar board materials and cherry board materials was measured, all of them were 10%.

(Example 3)
Protease was selected as the enzyme in the enzyme aqueous solution, and a 10% by weight enzyme aqueous solution was prepared using ion-exchanged water (pH of the aqueous solution was 5.0). Wood was immersed in this aqueous solution and allowed to stand for 30 minutes in a thermostatic bath at a temperature of 50 ° C. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured, and the warpage rate was improved by 83% to 0.5%. The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.5% or less, respectively. It was confirmed that no warping occurred.

Example 4
Galactanase was selected as the enzyme of the enzyme aqueous solution, and a 10% by weight enzyme aqueous solution was prepared using ion-exchanged water (pH of the aqueous solution was 4.5). The wood was immersed in this aqueous solution and allowed to stand in a constant temperature bath at a temperature of 40 ° C. for 10 hours. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured. As a result, the warpage rate was improved by 0.6% to 80%. The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.6% or less, respectively. It was confirmed that no warping occurred.

(Example 5)
Cellulase was selected as the enzyme of the enzyme aqueous solution, and a 3 wt% enzyme aqueous solution was prepared using ion-exchanged water (pH of the aqueous solution was 5.0). The wood was immersed in this aqueous solution and allowed to stand in a constant temperature bath at a temperature of 45 ° C. for 5 hours. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured, and the warpage rate improved by about 90% at 0.3%. The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were each 0.3% or less. It was confirmed that no warping occurred.

(Example 6)
Pectinase was selected as the enzyme in the enzyme aqueous solution, and a 2% by weight enzyme aqueous solution was prepared using ion-exchanged water (the pH of the aqueous solution was 4.0). The wood was immersed in this aqueous solution and allowed to stand for 4 hours in a thermostat at a temperature of 50 ° C. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured. As a result, the warpage rate improved by 0.4% or more by 85% or more. The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.4% or less, respectively. It was confirmed that no warping occurred.

(Example 7)
Xylanase 2 was selected as the enzyme in the enzyme aqueous solution, and a 2% by weight enzyme aqueous solution was prepared using ion-exchanged water. The viscosity was increased by adding 0.5% by weight of cyclodextrin to this solution (pH of the aqueous solution was 5.0). The cherry board material was immersed in this aqueous solution, and it left still for 4 hours in a 60 degreeC thermostat. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured, and the warpage rate was improved by 85% or more at 0.4%. The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples.
Thereafter, the entire surface of the cherry plate material was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.4% or less, respectively. It was confirmed that no new warping occurred.

(Example 8)
Xylanase 2 was selected as the enzyme in the enzyme aqueous solution, and a 2% by weight enzyme aqueous solution was prepared using ion-exchanged water. To this solution, 0.5% by weight of cyclodextrin was added to increase the viscosity (pH of the aqueous solution was 5.0). This aqueous solution was applied with a polyethylene brush in parallel with the direction of the path 3 of the surface 3 where warpage of the wood having a warpage rate of 2% and a moisture content of 8% is likely to occur. The surface 3 on which the warp of the wood tends to occur was judged from the images of the side surface 4 of the wood and the surface 3 on which the warp tends to occur.
The wood treated with this enzyme aqueous solution was allowed to stand in a constant temperature bath at a temperature of 60 ° C. for 4 hours. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured, and the warpage rate was improved by 75% or more by 0.5%. The evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the results of the experimental examples.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.5% or less, respectively. It was confirmed that no warping occurred.

Example 9
Xylanase 2 was selected as an enzyme in the enzyme aqueous solution, and a 2 wt% enzyme aqueous solution was prepared using ion-exchanged water (pH of the aqueous solution was 5.0). This aqueous solution was applied with an air brush (IS-800, manufactured by Anest Iwata Co., Ltd.) in parallel with the direction of the path 3 of the surface 3 where warpage of wood having a warpage rate of 2% and a water content of 10% is likely to occur. In order to select an application location arbitrarily, masking with a masking tape was performed in addition to the application location. At this time, it was confirmed that the concentration and pH of the enzyme aqueous solution applied from the airbrush did not change with the concentration and pH. The surface 3 where the warp of the wood is likely to occur was judged from the images of the appearance of the annual rings of the side surface 4 of the wood and the surface 3 where the warp is likely to occur.
The wood treated with this enzyme aqueous solution was allowed to stand for 4 hours in a thermostatic bath at a temperature of 60 ° C. Then, after lightly washing with water, after drying for 3 hours in a thermostatic bath at 60 ° C., the warpage rate was measured, and the warpage rate was improved by 75% or more by 0.5%. Further, the evaluation of the treatment method of the present invention confirmed at this time was equivalent to the evaluation assumed from the result of Experimental Example 1. Furthermore, it was confirmed from the results of electron micrographs that the effect of treatment with the enzyme was low at the masked portions.
Thereafter, the entire surface of this wood was subjected to laser processing under the same conditions as in Example 1, and the warpage rates measured after 1 hour and 1 week after laser processing were 0.5% or less, respectively. It was confirmed that no warping occurred.

DESCRIPTION OF SYMBOLS 1 Wood before warpage 2 Wood where warpage occurred 3 Surface where warpage is likely to occur 4 Cross section of wood for judging the direction where warpage is likely to occur 5 Size of wood warpage where warpage occurred 6 Table with positioning function 7 Warpage Image acquisition means 8 for a surface where warpage is likely to occur Image acquisition means 9 for a cross section of wood for judging the direction in which warpage is likely to occur 9 Holding jig

The present invention is utilized in industries related to wood processing and wood products.

Claims (1)

An internal stress relief method that reduces deformation of wood over time,
Contacting a part or all of the wood with an aqueous solution containing at least one enzyme selected from the group consisting of galactanase, cellulase, pectinase, and xylanase ;
A treatment step of reacting the material constituting the wood and the enzyme in an environment of 20 ° C. to 80 ° C .;
A drying step of drying the wood after the treatment step;
The internal stress removal method which reduces the time-dependent change of the timber containing.