Thermal storage board manufacturing method

Abstract

To provide a production method for a thermal storage board with less bleeding of heat storage material from a surface of the thermal storage board.SOLUTION: A production method for a thermal storage board includes: a moisture removal step S2 for removing moisture WA in a vessel 11a originated from wood of wood chips 11 by heating the wood chips 11; a thermal storage material introduction step S3 for introducing thermal storage material 12 into the vessel 11a through application of the thermal storage material 12 including latent thermal storage material in a melting state on the wood chips 11; an adhesive coating step S4 for applying adhesive 13 to the wood chips 11; a mat production step S5 for producing forming mat 10' from the wood chips 11 coated with the adhesive 13; a board forming step S6 for forming the thermal storage board 10 by hot-pressing the forming mat 10'.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a thermal storage board. [Background technology]

[0002] In recent years, proposals have been made to minimize indoor temperature changes by storing natural energy such as sunlight, thermal energy generated by air conditioning and heating systems, or thermal energy generated in daily life in latent heat storage materials, and absorbing and releasing heat in response to fluctuations in outdoor temperature.

[0003] For example, Patent Document 1 discloses a method for producing a heat storage board, in which a porous substrate such as a wooden board is impregnated with a curable heat storage composition at a temperature equal to or higher than the melting point of the heat storage material in the curable heat storage composition, and the curable heat storage composition impregnated in the porous substrate is cured. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-94202 Summary of the Invention [Problem to be solved by the invention]

[0005] However, according to the manufacturing method of the heat storage board shown in Patent Document 1, a large amount of heat storage material is contained in the voids of the porous substrate, and there is a risk that the heat storage material will seep out from the surface of the heat storage board during manufacturing and use.

[0006] The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a thermal storage board that reduces the seepage of the thermal storage material from the surface of the thermal storage board. [Means for solving the problem]

[0007] In view of the above problems, the inventors conducted extensive research and discovered a new finding: if latent heat storage material could be introduced into the conduits of the wood chips before they were used to form the heat storage board, the amount of latent heat storage material present in the gaps between the wood chips could be reduced, and the seepage of latent heat storage material from the heat storage board could be reduced.

[0008] The present invention has been made in consideration of these points, and the manufacturing method for a heat storage board according to the first invention is a manufacturing method for a heat storage board with heat storage properties, and is characterized by comprising: a moisture removal step of heating wood chips and removing moisture from the conduits derived from the wood of the wood chips; a heat storage material introduction step of applying a heat storage material containing a molten latent heat storage material to the wood chips from which the moisture has been removed and introducing the heat storage material into the conduits; an adhesive application step of applying an adhesive to the wood chips whose conduits have introduced the heat storage material; a mat manufacturing step of manufacturing a forming mat from the wood chips to which the adhesive has been applied; and a board molding step of molding the forming mat by heat pressing the forming mat.

[0009] According to the first aspect of the present invention, wood chips are heated to remove moisture and other substances from the conduits formed in the wood chips. By applying a heat storage material to the wood chips from which moisture has been removed, the heat storage material can be more easily introduced into the conduits formed in the wood chips, allowing more heat storage material to be retained inside the wood chips.

[0010] Furthermore, even if adhesive is applied during the adhesive application process, the heat storage material is trapped in the conduits, so the applied adhesive is likely to adhere to the surface of the wood chips. Therefore, even if a forming mat made from such wood chips is heated and pressed, the heat storage material impregnated in the wood chips is unlikely to seep out, so the latent heat storage material can be retained in the formed heat storage board and the adhesion between the wood chips can be improved.

[0011] The method for manufacturing a heat storage board according to the second invention is a method for manufacturing a heat storage board with heat storage properties, and is characterized by including: a moisture removal step of heating wood chips and removing moisture from the conduits derived from the wood of the wood chips; a heat storage material introduction step of applying a heat storage material containing a molten latent heat storage material and an adhesive to the wood chips from which the moisture has been removed, and attaching the adhesive to the wood chips so that at least a portion of the surface of the wood chips is exposed, and introducing the heat storage material into the conduits from the exposed surface of the wood chips; a mat preparation step of preparing a forming mat from the wood chips into which the heat storage material has been introduced; and a board formation step of forming a heat storage board by hot pressing the forming mat.

[0012] As in the first invention, in the second invention, the wood chips are heated to remove moisture and other substances from the conduits formed in the wood chips. By applying a heat storage material to the wood chips from which moisture has been removed, it becomes easier for the heat storage material to be introduced into the conduits formed in the wood chips, and more heat storage material can be retained inside the wood chips.

[0013] Unlike the first invention, the second invention does not perform the thermal storage material introduction step and the adhesive application step separately. Instead, in the thermal storage material introduction step, a thermal storage material containing a molten latent heat storage material and an adhesive are applied to wood chips from which moisture has been removed. At this time, the adhesive is applied to the wood chips so that at least a portion of the surface of the wood chips is exposed, and the thermal storage material is introduced into the conduit from the exposed surface of the wood chips. This allows the adhesive to adhere to the wood chips before the thermal storage material is introduced into the conduit, but since the surface of the wood chips is exposed from the adhesive, the thermal storage material can be introduced into the conduit from the exposed surface. Furthermore, the adhesive that adheres to a portion of the surface of the wood chips is impregnated into the wood chips, and thus a portion of the adhesive is impregnated into the surface layer of the wood chips, improving the adhesion between the wood chips when forming the thermal storage board.

[0014] In the second invention, the heat storage material introduction step of "applying a heat storage material containing a molten latent heat storage material and an adhesive to the wood chips" may mean either applying the heat storage material and adhesive to one wood chip simultaneously, or applying the heat storage material and adhesive with a time lag, and is not particularly limited as long as it is possible to "adhere the adhesive to the wood chips so that at least a portion of the surface of the wood chips is exposed, and introduce the heat storage material into the conduit from the exposed surface of the wood chips."

[0015] Here, in the heat storage material introduction process of the second invention, the temperature of the applied latent heat storage material and adhesive is not particularly limited, as long as the adhesive can be attached to the surface of the wood chips and the heat storage material can be introduced into the conduits of the wood chips.

[0016] However, in a more preferred embodiment of the second invention, in the heat storage material introducing step, the heat storage material is heated so that the viscosity of the heat storage material becomes lower than the viscosity of the adhesive.

[0017] According to this aspect, the viscosity of the heat storage material is lower than that of the adhesive, so the heat storage material applied to the wood chips is easier to introduce into the conduit than adhesive applied to the wood chips.

[0018] Furthermore, the method of applying the adhesive and the heat storage material is not particularly limited, but in a preferred embodiment of the second invention, in the heat storage material introduction step, the application of the adhesive and the application of the heat storage material are repeated alternately.

[0019] According to this aspect, by alternately applying adhesive and heat storage material, the heat storage material can be introduced into the conduit while preventing the adhesive from penetrating excessively into the wood chips in a single application, and further, the adhesive can be applied more uniformly to the surface of the wood chips.

[0020] Here, in the heat storage material introduction process of the first and second inventions, as long as the heat storage material is introduced into the conduits within the wood chips and the latent heat storage material contained in the heat storage material solidifies after the board molding process, the temperature conditions of the wood chips in the heat storage material introduction process are not particularly limited.

[0021] However, in the first and second inventions, a more preferred embodiment is that in the heat storage material introduction step, the temperature of the wood chips is adjusted to a temperature higher than the temperature of the heat storage material at the time of application, the heat storage material is applied to the wood chips in a temperature-adjusted state, and the heat storage material is introduced into the conduit.

[0022] According to this aspect, in the heat storage material introduction step, the wood chips are heated to a temperature equal to or higher than the temperature of the heat storage material at the time of application (specifically, equal to or higher than the temperature of the latent heat storage material in a molten state), and thereby the heat of the wood chips is input to the applied heat storage material. As a result, when the heat storage material is introduced into the conduit of the wood chips, the heat of the heat storage material is not taken away and an increase in the kinetic viscosity of the heat storage material can be suppressed, so that the heat storage material can be introduced into the conduit deeper inside the wood chips in a shorter time.

[0023] Here, if the latent heat storage material contained in the heat storage material is unlikely to seep out due to the heat pressure applied to the forming mat in the molding process of the first and second inventions, other work may be performed before the board molding process, and the content of that work is not particularly limited.

[0024] However, in the first and second aspects of the present invention, a more preferred embodiment is to apply water to the wood chips after the heat storage material introducing step and before the board forming step.

[0025] By applying water to the wood chips after the heat storage material introduction process and before the board molding process, the applied water turns into steam during the board molding process. This steam can push the heat storage material introduced into the conduit into the inside of the conduit. Furthermore, during the board molding process, the pressure of the evaporation of water adhering to the surface of the wood chips can prevent the latent heat storage material from seeping out from the surface of the heat storage board when it is heated and pressed.

[0026] Here, the water to be applied may be at room temperature or may be heated, as long as it can be vaporized and prevent the latent heat storage material from seeping out from the surface of the thermal storage board. However, in a more preferred embodiment of the first and second inventions, when applying the water, water heated to a temperature higher than the phase change temperature of the latent heat storage material is applied.

[0027] According to this aspect, by applying water heated to a temperature higher than the phase change temperature of the latent heat storage material, it is possible to prevent the latent heat storage material from locally solidifying and precipitating, thereby ensuring that the latent heat storage material is dispersed inside the wood chips.

[0028] Furthermore, such application of water may be carried out on the wood chips containing the heat storage material before the forming mat is produced, or may be carried out during the formation of the forming mat. In the first and second inventions, in a more preferred embodiment, the water is applied to the wood chips that form the surface of the forming mat.

[0029] According to this embodiment, the surface of the forming mat is heated by a heat press (hot press), and at this timing, the water on the surface of the forming mat is likely to vaporize. The generated steam pushes the introduced heat storage material further inside (to the back of the conduit) in the wood chip conduits on the surface of the forming mat, and flows into the forming mat. This makes it possible to prevent the latent heat storage material contained in the heat storage material 12 from seeping out from the surface of the thermal storage board after molding.

[0030] Furthermore, the thermal storage board may be constructed with a single layer structure or multiple layers, so long as the thermal storage capacity and mechanical strength can be ensured. However, in a more preferred embodiment of the first and second inventions, the method for manufacturing a thermal storage board is a method for manufacturing a thermal storage board having a pair of surface layers arranged on both sides and an inner layer arranged between the pair of surface layers, wherein in the moisture removal step, moisture is removed from first wood chips that form the surface layers and second wood chips that are larger than the first wood chips and form the inner layer, and in the thermal storage material introduction step, the thermal storage material is applied to the first and second wood chips so that a greater amount of thermal storage material is introduced per unit weight into the second wood chips than into the first wood chips, and when applying water, the water is applied to the first and second wood chips so that a greater amount of water is applied per unit weight into the first wood chips than into the second wood chips.

[0031] According to this aspect, the second wood chips have a larger amount of heat storage material introduced per unit weight than the first wood chips, which improves the heat storage capacity of the internal layer of the heat storage board and makes it less likely for the latent heat storage material to seep out of the first wood chips that make up the surface layer of the heat storage board.

[0032] Furthermore, when applying water, the water is applied to the first and second wood chips so that the amount of water applied per unit weight is greater for the first wood chips than for the second wood chips. As a result, during the board forming process, the water contained in the surface layer of the thermal storage board evaporates and steam is sent to the inner layer, which has larger voids than the surface layer, and flows out from the side of the thermal storage board. This flow of water steam can prevent the latent heat storage material from seeping out from the surface of the thermal storage board.

[0033] Here, as long as the heat storage properties of the heat storage board can be ensured, the heat storage material (heat storage composition) may be composed only of latent heat storage material, or may be a mixture containing other resins, solvents, etc., and its composition is not particularly limited.

[0034] However, in the first and second inventions, a more preferred embodiment is that the heat storage material is a mixture of the latent heat storage material and room temperature curing resin, and the latent heat storage material of the mixture impregnated into the wood chips is maintained in a molten state from the heat storage material introduction step until the board molding step is completed, and after the board molding step is completed, the hardening of the room temperature curing resin is completed with the latent heat storage material in a molten state.

[0035] According to this embodiment, after the board forming step is completed, the room temperature curable resin hardens while forming a fine three-dimensional network structure, and the latent heat storage material is held and solidified within the three-dimensional network structure. As a result, it is possible to prevent the latent heat storage material from seeping out of the mixture.

[0036] Unlike adhesives made of thermosetting resins, the hardening of which is accelerated by a polymerization reaction or a crosslinking reaction due to heating, room-temperature curing adhesives are not easily hardened by heating. Therefore, it is obvious to those skilled in the art that by adjusting the ratio of the main components and solvent of the room-temperature curing adhesive, and by adjusting the type of latent heat storage material, heating temperature, and heating time, it is possible to "complete the hardening of the room-temperature curing resin after the molding process is completed, with the latent heat storage material in a molten state." [Effects of the Invention]

[0037] The thermal storage board according to the present invention provides a method for manufacturing a thermal storage board in which little thermal storage material seeps out from the surface of the thermal storage board. [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 3 is a flow chart for explaining a method for manufacturing a thermal storage board according to a first embodiment of the first invention. [Figure 2A] FIG. 2 is a schematic conceptual diagram for explaining the moisture removal step shown in FIG. [Figure 2B] FIG. 2 is a schematic conceptual diagram for explaining the heat storage material introducing step shown in FIG. [Figure 2C]FIG. 2 is a schematic conceptual diagram for explaining the adhesive application step shown in FIG. [Figure 2D] FIG. 2 is a schematic conceptual diagram for explaining the mat preparation step and the board forming step shown in FIG. [Figure 2E] FIG. 2 is a schematic cross-sectional view of a heat storage board manufactured by the manufacturing method shown in FIG. [Figure 3] FIG. 4 is a flow chart for explaining a method for manufacturing a thermal storage board according to a second embodiment of the first invention. [Figure 4A] FIG. 4 is a schematic conceptual diagram for explaining the water application step shown in FIG. 3. [Figure 4B] FIG. 4 is a schematic conceptual diagram for explaining the state of the heat storage material present inside the wood chips in the board forming process shown in FIG. 3. [Figure 5] FIG. 10 is a flow chart for explaining a method for manufacturing a thermal storage board according to a third embodiment of the first invention. [Figure 6A] 6 is a schematic conceptual diagram for explaining the mat production process shown in FIG. 5, where (a) is a diagram showing the process of forming a first surface layer mat corresponding to the surface layer, (b) is a diagram for explaining the process of laminating an internal layer mat corresponding to the internal layer onto the first surface layer mat corresponding to the surface layer, and (c) is a diagram for explaining the process of further laminating a second surface layer mat corresponding to the surface layer onto the internal layer mat. [Figure 6B] FIG. 6 is a schematic cross-sectional view of a heat storage board manufactured by the manufacturing method shown in FIG. 5. [Figure 7] FIG. 10 is a part of a flow chart for explaining a method for manufacturing a thermal storage board according to a fourth embodiment of the first invention, and is a flow chart for explaining details of a mat manufacturing step. [Figure 8] 8(a) to 8(c) are schematic diagrams illustrating the first to third water application steps shown in FIG. [Figure 9] FIG. 10 is a flow chart for explaining a method for manufacturing a thermal storage board according to a modified example of the fourth embodiment of the first invention. [Figure 10] FIG. 10 is a flow chart for explaining a method for manufacturing a thermal storage board according to a first embodiment of a second invention. [Figure 11]11(a) to 11(c) are schematic diagrams for explaining the details of the heat storage material introducing step shown in FIG. [Figure 12] FIG. 12 is another schematic diagram for explaining the details of the heat storage material introducing step shown in FIG. [Figure 13] FIG. 10 is a flow chart for explaining a method for manufacturing a thermal storage board according to a second embodiment of the second invention. [Figure 14] FIG. 10 is a flow chart for explaining a method for manufacturing a thermal storage board according to a third embodiment of the second invention. [Figure 15] FIG. 10 is a part of a flow chart for explaining a method for manufacturing a thermal storage board according to a fourth embodiment of the second invention, and is a flow chart for explaining details of a mat manufacturing step. [Figure 16] FIG. 10 is a flow chart for explaining a method for manufacturing a thermal storage board according to a modified example of the fourth embodiment of the second invention. DETAILED DESCRIPTION OF THE INVENTION

[0039] A. First embodiment of the present invention [First embodiment] A method for manufacturing a thermal storage board according to a first embodiment of the first invention will be described below with reference to Figures 1 to 2E. Figure 1 is a flow diagram for explaining the method for manufacturing a thermal storage board according to the first embodiment of the first invention, Figures 2A to 2D are schematic diagrams for explaining the details of each step shown in Figure 1, and Figure 2E is a schematic cross-sectional view of a thermal storage board manufactured by the manufacturing method shown in Figure 1.

[0040] In this embodiment, a heat storage board 10 having heat storage properties as shown in Fig. 2E is manufactured. The heat storage board 10 is a board material used as a building material such as a wall material, floor material, or ceiling material, or as a base material for fittings or storage furniture. The heat storage board 10 is a board formed by bonding wood chips 11 containing a heat storage material with an adhesive and then thermocompressing the wood chips 11.

[0041] The wood chips 11 that make up the heat storage board 10 are bonded together with an adhesive, and the conduits of the wood chips 11 are filled with a resin material, so that the wood chips 11 are filled with a larger amount of heat storage material than the wood chips that make up the heat storage board shown in, for example, Patent Document 1. The heat storage material is a resin material that contains a latent heat storage material, as will be described later.

[0042] [Chip manufacturing process S1] In this manufacturing method, first, a chip preparation step S1 shown in Fig. 1 is carried out. In this step, wood chips are prepared from wood. The wood chips 11 are pieces of wood made from coniferous trees such as pine, cedar, and cypress, or broad-leaved trees such as lauan, capol, and poplar. The wood chips 11 are prepared by crushing or cutting wood or the like into small pieces using a crusher or a cutting machine. The small pieces of chips may be classified into desired sizes using a sieve.

[0043] [Moisture removal process S2] Although the surfaces of the prepared wood chips 11 are dried to a certain extent, as shown in the left diagram of Fig. 2A, moisture WA remains in the conduits 11a of the wood chips 11. Therefore, in this embodiment, a moisture removal step S2 shown in Fig. 1 is performed.

[0044] In this process, as shown in FIG. 2A, wood chips 11 are heated, and the resulting heat H1 removes moisture from conduits 11a derived from the wood of wood chips 11. Specifically, wood chips 11 are heated for a longer time than in the past. In this case, the heating temperature may be higher than in the past. Note that the moisture removal does not necessarily remove all of the moisture from wood chips 11.

[0045] For example, the heating temperature of the wood chips 11 is in the range of 50 to 200°C, and the heating time is in the range of 10 to 120 minutes. Within this heating condition range, it is preferable that the moisture content of the wood chips 11 is 9% by mass or less, and more preferably 5% by mass or less.

[0046] [Heat storage material introduction process S3] Next, the heat storage material introduction step S3 shown in Fig. 1 is performed. In this step, as shown in Fig. 2B, heat storage material 12 containing a molten latent heat storage material is applied to the wood chips 11 from which moisture has been removed in conduit 11a, and heat storage material 12 is introduced into conduit 11a.

[0047] The heat storage material 12 is a resin composition containing a latent heat storage material, and its composition is not particularly limited as long as it can ensure heat storage properties. Specifically, it may be a mixture further containing an organic solvent, a thermoplastic resin, a thermosetting resin, or the like.

[0048] The phase change temperature (melting point) of the latent heat storage material from the liquid phase to the solid phase is preferably 18 to 35°C. Examples of latent heat storage materials include saturated aliphatic hydrocarbons such as n-paraffin and paraffin wax, typically having 16 to 24 carbon atoms, composed of n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, etc., or mixtures thereof; mono- or polyunsaturated aliphatic hydrocarbons such as linear α-olefins, typically having 16 to 24 carbon atoms, composed of 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, etc., or mixtures thereof; long-chain fatty acids such as octanoic acid, capric acid, lauric acid, myristic acid, etc., or mixtures thereof; esters of the above fatty acids, polyether compounds such as polyethylene glycol, etc. For example, if the latent heat storage material melts at 28°C, n-octadecane is selected, and if the latent heat storage material melts at 18°C, n-hexadecane is selected. Furthermore, a plurality of latent heat storage materials having different melting points may be mixed and used.

[0049] When the heat storage material contains a thermosetting resin, the thermosetting resin may be a room temperature curing or thermosetting thermosetting resin, such as urea resin, melamine resin, phenolic resin, epoxy resin, unsaturated polyester resin, polyurethane resin, diallyl phthalate resin, silicone resin, or alkyd resin. In this embodiment, the thermosetting resin is preferably a room temperature curing thermosetting resin such as a two-component room temperature curing polyurethane resin obtained using a polyol and an isocyanate.

[0050] It is generally known that when the thermosetting resin is a room-temperature curing resin such as a two-component room-temperature curing polyurethane resin, the timing of curing can be easily adjusted by adjusting not only the amount of heat input to the resin but also the mixing ratio, the type or amount of reaction catalyst, etc. Therefore, as will be described later, it is easy to make adjustments so that "the curing of the room-temperature curing resin is completed when the latent heat storage material is in a molten state."

[0051] In this way, the latent heat storage material can be maintained in a molten state in the form of a mixture while the room-temperature curable resin can be cured, so that the room-temperature curable resin hardens while forming a fine three-dimensional network structure, and can be solidified in a state in which the latent heat storage material is held inside the three-dimensional network structure. As a result, it is possible to make it difficult for the latent heat storage material to seep out of the mixture.

[0052] Here, when applying the heat storage material 12, it is preferable that the heat storage material 12 is in a liquid state, and the heat storage material 12 is applied in a state in which at least the latent heat storage material is molten. Furthermore, the wood chips 11 may be heated in the moisture removal step S2 and then cooled by, for example, standing to cool.

[0053] However, a preferred embodiment of the heat storage material introducing step S3 is to apply the heat storage material 12 while maintaining the wood chips 11 in a heated state (i.e., in a continuously heated state) in the moisture removing step S2. Specifically, as shown in Fig. 2B, the temperature of the wood chips 11 is adjusted to a temperature equal to or higher than the temperature of the heat storage material 12 at the time of application, and the heat storage material 12 is applied to the wood chips 11 in the temperature-adjusted state, and the heat storage material 12 is introduced into the conduit 11a. For example, if the temperature of the wood chips 11 is lower than the temperature of the heat storage material 12 at the time of application, the wood chips 11 are heated with heat H2 from a temperature adjustment device (not shown), as shown in Fig. 2B, and the heat storage material 12 is applied to the wood chips 11 in the heated state, and the heat storage material 12 is introduced into the conduit 11a.

[0054] In the heat storage material introduction step S3, the wood chips 11 are heated to a temperature equal to or higher than the temperature of the molten latent heat storage material, so that the heat of the wood chips 11 is input to the applied heat storage material 12. As a result, when the heat storage material 12 is introduced into the conduits 11a of the wood chips 11, the heat of the heat storage material 12 is not removed, and an increase in the kinetic viscosity of the heat storage material 12 can be suppressed. This allows the heat storage material 12 to be introduced into the conduits 11a further inside the wood chips 11 in a shorter time.

[0055] In the heat storage material introduction process S3, the heat storage material 12 in a flowable state such as a liquid may be applied to the wood chips 11 by spraying, the heat storage material 12 may be applied by brushing, or the wood chips 11 may be mixed with the heat storage material 12, and the application method is not particularly limited.

[0056] In this way, by applying the heat storage material 12 to the wood chips 11 from which moisture has been removed in the moisture removal step S2, the heat storage material 12 can be easily introduced into the conduits 11a formed in the wood chips 11. Therefore, more heat storage material 12 can be held inside the wood chips 11.

[0057] [Adhesive application process S4] Next, the adhesive application step S4 shown in Fig. 1 is performed. In this step, adhesive 13 is applied to the wood chips 11 in which the heat storage material 12 has been introduced into the conduits 11a. In this embodiment, since the heat storage material 12 has already been introduced into the conduits 11a of the wood chips 11 in the heat storage material introduction step S3, the adhesive 13 easily adheres to the surface of the wood chips 11. This makes it possible to increase the adhesion between the wood chips 11, 11 with a small amount of adhesive 13.

[0058] Although there are no particular limitations on the adhesive 13, in this embodiment it is preferable that it be a thermosetting resin adhesive, such as a polyurethane adhesive, a urea resin adhesive, a melamine resin adhesive, a urea-melamine co-condensation resin adhesive, or a phenolic resin adhesive.

[0059] Alternatively, an isocyanate adhesive may be used as the adhesive 13. Examples of the isocyanate adhesive include MDI (diphenylmethane diisocyanate), TDI (tolylene diisocyanate), MDI prepolymer, TDI prepolymer, and a mixture of two or more of these.

[0060] Since the isocyanate adhesive is a moisture-curing adhesive that reacts with moisture and hardens, for example, by applying water as shown in the second embodiment, hardening of the adhesive 13 can be promoted at the timing of board formation, thereby improving the adhesion between the wood chips 11.

[0061] In the adhesive application step S4, the adhesive 13 may be applied to the wood chips 11 by spraying, the heat storage material 12 may be applied by brushing, or the wood chips 11 may be mixed with the adhesive 13; the application method is not particularly limited. Furthermore, in the mat preparation step S5 described below, the adhesive 13 may be applied while the wood chips are being stacked in layers.

[0062] [Mat production process S5] Next, the mat preparation step S5 shown in Fig. 1 is carried out. In this step, as shown in Fig. 2D, a forming mat 10' is prepared from wood chips 11 to which adhesive 13 has been applied. In this embodiment, the wood chips 11 are placed on a base 61 of a press device shown in Fig. 2D and formed into a mat (formed into a forming mat). At this time, the forming mat 10' may be prepared by laying the wood chips 11 in layers in the thickness direction of the forming mat 10'.

[0063] [Board forming process S6] Next, the board forming step S6 shown in Fig. 1 is carried out. As shown in Fig. 2D, in this step, the produced forming mat 10' is hot-pressed to form the thermal storage board 10. Specifically, the forming mat 10' is hot-pressed using a heated pressing member 62 of a hot press device to form the thermal storage board 10. At this time, both the base 61 and the pressing member 62 are heated. The temperature (heating temperature) at which the forming mat 10' is formed into a board shape depends on the type of adhesive 13, but is in the range of 120 to 220°C, for example, and the pressure during hot pressing is about 2 to 5 MPa, for example.

[0064] In this embodiment, as described above, even if the adhesive 13 is applied in the adhesive application step S4, the heat storage material 12 penetrates the conduits 11a, so the applied adhesive 13 easily adheres to the surface of the wood chips 11. Therefore, even if a forming mat 10' made from such wood chips 11 is hot-pressed, the heat storage material 12 impregnated in the wood chips 11 is unlikely to seep out. This makes it possible to retain the latent heat storage material inside the wood chips 11 of the formed heat storage board 10, and also to increase the adhesion between the wood chips 11, 11, thereby increasing the strength of the heat storage board 10.

[0065] Here, when a mixture of a latent heat storage material and a room-temperature curing resin is used as the heat storage material 12, it is preferable to maintain the latent heat storage material of the mixture impregnated into the wood chips 11 in a molten state from the heat storage material introduction step S3 until the board molding step S6 is completed. Furthermore, after the board molding step S6 is completed, the hardening of the room-temperature curing resin is completed while the latent heat storage material is in a molten state. Thereafter, the heat storage board 10 is allowed to cool, thereby solidifying the latent heat storage material.

[0066] After the board forming step S6 is completed, the room temperature curing resin hardens, forming a fine three-dimensional network structure, and the latent heat storage material is held and solidified within the three-dimensional network structure. As a result, it is possible to prevent the latent heat storage material from seeping out of the mixture.

[0067] Second Embodiment A method for manufacturing a thermal storage board 10 according to a second embodiment of the first invention will be described below with reference to Figs. 3 to 4B. Fig. 3 is a flow diagram illustrating a method for manufacturing a thermal storage board 10 according to the second embodiment of the first invention. Fig. 4A is a schematic conceptual diagram illustrating the water application step S70 shown in Fig. 3. Fig. 4B is a schematic conceptual diagram illustrating the state of the thermal storage material 12 present inside the wood chips 11 in the board forming step S6 shown in Fig. 3.

[0068] The present embodiment differs from the manufacturing method according to the first embodiment in that a water application step S70 is newly added. Therefore, detailed descriptions of the steps similar to those of the first embodiment of the first invention will be omitted below, and only the differences will be described.

[0069] In this embodiment, water is applied to the wood chips 11 after the heat storage material introducing step S3 and before the board forming step S6. Specifically, as shown in Fig. 3, water WB is applied to the wood chips 11 after the adhesive applying step S4 and before the mat making step S5.

[0070] 4A, the heat storage material 12 is introduced into the conduit 11a, and water WB is applied to the wood chips 11 having the adhesive 13 attached to their surfaces. This allows the water WB to adhere to the surfaces of the wood chips 11. In this embodiment, the adhesive 13 is applied in advance, and then the water WB is applied, so that the adhesion of the adhesive 13 to the wood chips 11 is less likely to be affected by the application of the water WB. However, as long as the adhesion of the adhesive 13 can be ensured, for example, the adhesive 13 may be applied after the application of the water WB, or the adhesive 13 and the water WB may be applied (sprayed) simultaneously.

[0071] Here, the water WB may be sprayed, for example, by a sprayer. When applying the water WB, water WB (specifically, hot water) heated to a temperature higher than the phase change temperature of the latent heat storage material of the heat storage material 12 may be applied. Applying water in this manner can prevent the latent heat storage material from locally solidifying and precipitating (or segregating if it is a mixture) before forming the heat storage board 10. This ensures that the latent heat storage material is dispersed inside the wood chips 11.

[0072] After the application of water, the mat is prepared in the mat making step S5, and during the board forming step S6, the applied water turns into steam S due to the heat from the base 61 and the pressing member 62, as shown in Fig. 4B. This steam S can force the heat storage material 12 introduced into the conduit 11a into the inside of the conduit 11a, as shown in Fig. 4B. Furthermore, during the board forming step S6, the pressure of the steam S adhering to the surface of the wood chips 11 can prevent the latent heat storage material from seeping out from the surface of the heat storage board 10 during heat pressing.

[0073] In this embodiment, water is applied to the wood chips 11 into which the heat storage material 12 has been introduced before the mat-making step S5, but water may also be applied in the mat-making step S5, for example. For example, water may be applied to the surfaces of the wood chips 11 that form the surface of the forming mat 10'. In this case, water may be applied to the wood chips 11 that are stacked in the stage of making the forming mat 10', or the wood chips 11 that form the surface of the forming mat 10' (wood chips into which the heat storage material has been introduced) may be prepared in advance, and water may be applied to them before making the forming mat 10'.

[0074] The surface of the forming mat 10' is heated by the base 61 and pressing member 62 of the heat pressing device (hot press device), and at this timing the water WB applied to the wood chips 11 turns into steam S. This steam S pushes the introduced heat storage material further in (to the back of the conduit) in the conduits of the wood chips on the surface of the forming mat 10', and flows into the interior of the forming mat 10'. This makes it possible to prevent the latent heat storage material contained in the heat storage material 12 from seeping out from the surface of the heat storage board 10 after molding, and furthermore, the steam flowing inside can promote the hardening of the adhesive 13 if it is an isocyanate adhesive.

[0075] Third Embodiment A method for manufacturing a thermal storage board 10 according to a third embodiment of the first invention will be described below with reference to Figs. 5 to 6B. Fig. 5 is a flow diagram illustrating a method for manufacturing a thermal storage board 10 according to the third embodiment of the first invention. Figs. 6A(a) to (c) are schematic conceptual diagrams illustrating the mat manufacturing step S5 shown in Fig. 5. Fig. 6B is a schematic cross-sectional view of a thermal storage board 10 manufactured by the manufacturing method shown in Fig. 5.

[0076] The manufacturing method of this embodiment differs from that of the first embodiment in that first and second wood chips 11A, 11B are used for the heat storage board 10. Therefore, detailed explanations of the same steps as in the first embodiment will be omitted below, and only the differences will be explained.

[0077] In this embodiment, as shown in FIG. 6B, a thermal storage board 10 is manufactured that includes a pair of surface layers 10A, 10C arranged on both sides and an internal layer 10B arranged between the pair of surface layers 10A, 10C.

[0078] The pair of surface layers 10A, 10C are formed to sandwich the inner layer 10B from both sides thereof. The first wood chips 11A, which form the base material of each surface layer 10A (10C), are bonded to each other in each surface layer 10A (10C) with a first adhesive. In this embodiment, the second wood chips 11B are bonded to each other in the inner layer 10B with a second adhesive. The surface layer 10A (10C) and the inner layer 10B contain a heat storage material, and the amount of heat storage material contained per unit weight of the second wood chips 11B in the inner layer 10B is greater than the amount of heat storage material contained per unit weight of the first wood chips 11A in the surface layer 10A (10C).

[0079] The following describes a method for manufacturing the heat storage board 10. Note that the order of the steps for the first and second wood chips is not particularly limited, as long as the steps from the first chip production step S11 to the first adhesive application step S14 shown below are in order, and the steps from the second chip production step S21 to the second adhesive application step S24 are in order.

[0080] First, in this embodiment, a first chipping process S11 and a second chipping process S21 are performed. In the first chipping process S11, first wood chips 11A that form the surface layer 10A are produced. In the second chipping process S21, second wood chips 11B that are larger than the first wood chips 11A and that form the inner layer 10B are produced.

[0081] The sizes of the first wood chips 11A and the second wood chips 11B can be adjusted by a commonly known method, for example, by changing the conditions for crushing or cutting a predetermined piece of wood. Furthermore, the first wood chips 11A and the second wood chips 11B may be classified using a sieve with a predetermined mesh size.

[0082] Next, in a first chip moisture removal step S12, moisture is removed from the conduits 11a derived from the wood of the first wood chips 11A, and in a second chip moisture removal step S22, moisture is removed from the conduits 11a derived from the wood of the second wood chips 11B. The moisture removal is performed in the same manner as described in the first embodiment, as shown in Fig. 2A etc.

[0083] Next, in a first heat storage material introduction step S13, the heat storage material 12 is applied to the first wood chips 11A and the heat storage material 12 is introduced into the conduit 11a. Similarly, in a second heat storage material introduction step S23, the heat storage material 12 is applied to the second wood chips 11B and the heat storage material 12 is introduced into the conduit 11a. The method for applying the heat storage material 12 is the same as that described in the first embodiment, as shown in Fig. 2B etc.

[0084] In this embodiment, the heat storage material 12 is applied to the first and second wood chips 11A, 11B so that a greater amount of heat storage material 12 is introduced per unit weight into the second wood chips 11B than into the first wood chips 11A. This allows a greater amount of heat storage material 12 to be introduced per unit weight into the second wood chips 11B than into the first wood chips 11A. This improves the heat storage capacity of the inner layer 10B of the heat storage board 10, and makes it less likely for the latent heat storage material to seep out of the first wood chips 11A that make up the surface layers 10A, 10C of the heat storage board 10. In this embodiment, the same heat storage material is applied to the first wood chips 11A and the second wood chips 11B, but different materials may be selected from the examples of heat storage materials described above.

[0085] Next, in a first adhesive application step S14, an adhesive (first adhesive) is applied to the first wood chips 11A in which the heat storage material 12 has been introduced into the conduit 11a, and in a second adhesive application step S24, an adhesive (second adhesive) is applied to the second wood chips 11B in which the heat storage material 12 has been introduced into the conduit 11a. The adhesive is applied in the same manner as described in the first embodiment, as shown in Fig. 2C etc.

[0086] The first adhesive is not particularly limited, but in this embodiment, it is preferably a thermosetting resin adhesive. Examples of thermosetting resin adhesives include those exemplified as adhesive 13 in the first embodiment, but among these, isocyanate-based adhesives, urea resin adhesives, melamine resin adhesives, urea-melamine co-condensation resin adhesives, and phenolic resin adhesives are preferred. A more preferred first adhesive is a urea resin adhesive or a melamine resin adhesive.

[0087] The second adhesive is also not particularly limited, and examples include the adhesives exemplified as adhesive 13 in the first embodiment, but among these, isocyanate-based adhesives such as MDI (diphenylmethane diisocyanate), TDI (tolylene diisocyanate), MDI prepolymer, TDI prepolymer, and mixtures of two or more of these are more preferred.

[0088] Next, the mat preparation step S5 is performed. Specifically, as shown in Figures 5 and 6A(a), in the first surface layer formation step S51, a first surface layer mat 10a corresponding to the surface layer 10A is formed on the base 61. The first surface layer mat 10a uses the first wood chips 11A to which the first adhesive has been applied in the first adhesive application step S14.

[0089] 5 and 6A(b), an inner layer mat 10b corresponding to the inner layer 10B is laminated on the first surface layer mat 10a corresponding to the surface layer 10A. The inner layer mat 10b is made of second wood chips 11B to which the second adhesive has been applied in the second adhesive application step S24.

[0090] 5 and 6A(c), a second surface layer mat 10c corresponding to the surface layer 10C is laminated on the inner layer mat 10b. The second surface layer mat 10c is made of the first wood chips 11A coated with the first adhesive in the first adhesive application step S14.

[0091] In this way, the forming mat 10' can be produced. The forming mat 10' is subjected to the board forming step S6 in the same manner as in the first embodiment. As a result, the heat storage board 10 shown in Fig. 6B can be obtained.

[0092] In this embodiment, the first and second adhesives are applied to the first and second wood chips 11A, 11B before the forming mat 10' is produced, but the first and second adhesives may also be applied to the first and second wood chips 11A, 11B when forming the first and second surface layer mats 10a, 10c and the inner layer mat 10b.

[0093] [Fourth embodiment] A method for manufacturing a thermal storage board 10 according to a fourth embodiment of the first invention will be described below with reference to Fig. 7 and Fig. 8. Fig. 7 is a part of a flow diagram for explaining a method for manufacturing a thermal storage board according to the fourth embodiment of the first invention, and is a flow diagram for explaining details of the mat manufacturing step S5. Figs. 8(a) to (c) are schematic diagrams for explaining the first to third water application steps S71 to S73 shown in Fig. 7.

[0094] The manufacturing method of this embodiment differs from that of the third embodiment in that first to third water application steps S71 to S73 are newly performed in the mat fabrication step S5. Therefore, detailed description of the steps similar to those of the third embodiment will be omitted below, and only the differences will be described.

[0095] In this embodiment, as shown in Figures 7 and 8(a), a first water application step S71 is performed after the first surface layer formation step S51. In this step, water WB is applied to the first surface layer mat 10a, which corresponds to the surface layer 10A on which the base 61 is arranged, using a spray nozzle 41 or the like. The application of water WB is performed in the same manner as the water application step S70 shown in Figure 3.

[0096] 7 and 8(b), after the inner layer forming step S52, a second water applying step S72 is performed. In this step, water WB is applied to the inner layer mat 10b using a spray nozzle 41 or the like.

[0097] 7 and 8(c), the second surface layer forming step S53 is followed by a third water application step S73. In this step, water WB is applied to the second surface layer mat 10c using a spray nozzle 41 or the like. The water WB is applied to the first and second wood chips 11A, 11B so that the amount of water WB applied per unit weight is greater for the first wood chips 11A of the first and second surface layer mats 10a, 10c than for the second wood chips 11B of the inner layer mat 10b.

[0098] In this way, in the board forming step S6, the water contained in the surface layers 10A, 10C of the thermal storage board 10 evaporates and the resulting steam is sent to the internal layer 10B, which has larger voids than the surface layers 10A, 10C, and flows out from the side of the thermal storage board 10. This flow of water vapor can prevent the latent heat storage material from seeping out from the surface of the thermal storage board 10.

[0099] In this embodiment, the first to third water application steps S71 to S73 are performed in the mat-making step S5. However, as shown in a modified example in Fig. 9, for example, a first water application step S70A may be performed after the first adhesive application step S14 and before the mat-making step S5 to apply water to the first wood chips 11A, and a second water application step S70B may be performed after the second adhesive application step S24 and before the mat-making step S5 to apply water to the second wood chips 11B.

[0100] B. Second embodiment of the present invention The embodiment of the second invention differs from the embodiment of the first invention in that in the embodiment of the first invention, the heat storage material introduction process and the adhesive application process were carried out separately in that order, whereas in the embodiment of the second invention described below, adhesive is applied in the heat storage material introduction process, and the adhesive application process is not provided separately.

[0101] First to fourth embodiments of the second invention will be described below with reference to Figures 10 to 16. In these embodiments, the wood chips, heat storage material including latent heat storage material, adhesive, water, etc. are the same as those exemplified in the first to fourth embodiments of the first invention. Therefore, in the following embodiments of the second invention, detailed descriptions of similar steps and similar materials will be omitted.

[0102] [First embodiment] A method for manufacturing a thermal storage board according to the first embodiment of the second invention will be described below with reference to Fig. 10 to Fig. 12. Fig. 10 is a flow diagram for explaining the method for manufacturing a thermal storage board according to the first embodiment of the second invention, Fig. 11(a) to (c) are schematic diagrams for explaining details of the thermal storage material introducing step shown in Fig. 10, and Fig. 12 is another schematic diagram for explaining details of the thermal storage material introducing step shown in Fig. 11.

[0103] First, in this embodiment, as in the first embodiment of the present invention, a chip preparation step S1 and a moisture removal step S2 are performed in sequence, as shown in Fig. 10. In the moisture removal step S2, as already explained in Fig. 2A, the wood chips 11 are heated to remove moisture WA from the conduits 11a derived from the wood of the wood chips 11.

[0104] Unlike the embodiment according to the first aspect of the present invention, in the heat storage material introducing step S3A shown in Fig. 10, an adhesive is also applied. Specifically, in the heat storage material introducing step S3A, a heat storage material 12 containing a molten latent heat storage material and an adhesive 13 are applied to wood chips 11 from which moisture has been removed (see Fig. 11(a)). The amounts of the heat storage material 12 and adhesive 13 applied and the method of transporting or stirring the chips are adjusted to adhere at least the adhesive to the wood chips 11 so that a portion of the surface of the wood chips 11 is exposed, as shown in Fig. 11(a). Then, the heat storage material 12 is introduced into the conduit 11a from the exposed surface of the wood chips 11, as shown in Figs. 11(b) and 11(c).

[0105] In this embodiment, the heat storage material 12 and adhesive 13 may be applied to a collection of wood chips 11 contained in a single agitator while the heat storage material 12 and adhesive 13 are being added (specifically, while being applied), and the heat storage material 12 may be introduced into the conduit 11a. In this case, by setting the material settings and application conditions, for example, by making the amount of adhesive 13 applied less than the amount of heat storage material 12 applied, or by heating the heat storage material 12 so that the viscosity of the heat storage material 12 in which the latent heat storage material is melted becomes lower than the viscosity of the adhesive 13, wood chips 11 in the state shown in Figures 11(b) and (c) can be obtained.

[0106] Therefore, the adhesive 13 may be applied and then the heat storage material 12 may be applied, provided that the adhesive 13 does not cover the entire surface of the wood chips 11, preventing the heat storage material 12 from being introduced into the conduits 11a of the wood chips 11. In this case, using a stirring device 90 shown in Fig. 12 (described later), the adhesive 13 may be supplied from two adjacent supply holes 93, 93 on the upstream side of the conveying direction of the wood chips 11, and the heat storage material 12 may be supplied from two adjacent supply holes 93, 93 on the downstream side, although this is different from the supply method shown in Fig. 12.

[0107] For example, in this embodiment, as described above, in the heat storage material introducing step S3A, the heat storage material 12 is heated so that the viscosity of the heat storage material 12 is lower than the viscosity of the adhesive 13. Specifically, in this embodiment, as described above, the above-described materials are selected on the premise that the heat storage performance of the heat storage board and the adhesiveness of the wood chips 11 can be ensured, and the heat storage material 12 is heated by a heating device (not shown) so that the above-described viscosity is satisfied. As a result, the viscosity of the heat storage material 12 is lower than the viscosity of the adhesive 13, and therefore the heat storage material 12 applied to the wood chips 11 is more easily introduced into the conduit 11a than the adhesive applied to the wood chips 11.

[0108] In this embodiment, as in the first aspect of the invention, the wood chips 11 may be maintained in a heated state (i.e., continuously heated) before the application of the heat storage material 12. Specifically, the wood chips 11 are heated by heat H2 from a heat source (not shown) to a temperature equal to or higher than the temperature at which the heat storage material 12 was applied, and the heat storage material 12 is applied to the heated wood chips 11, and the heat storage material 12 is introduced into the conduit 11a.

[0109] In this manner, also in this embodiment, by applying the heat storage material 12 to the wood chips 11 from which moisture has been removed, the heat storage material 12 can be easily introduced into the conduits 11a formed in the wood chips 11. Therefore, a larger amount of the heat storage material 12 can be retained inside the wood chips 11.

[0110] 1, in this embodiment, the heat storage material introducing step S3 and the adhesive applying step S4 are not performed separately, and in the heat storage material introducing step S3A, wood chips from which moisture has been removed are coated with a heat storage material 12 containing a molten latent heat storage material and an adhesive 13. At this time, application conditions and the like are set so that at least a portion of the surface of the wood chips 11 is exposed and the heat storage material 12 is introduced into the conduit 11a from the exposed surface of the wood chips 11.

[0111] As a result, the adhesive 13 may adhere to the wood chips 11 before the thermal storage material 12 is introduced into the conduit, but because the surface of the wood chips 11 is exposed from the adhesive 13, the thermal storage material 12 can be introduced into the conduit from the exposed surface. Furthermore, the adhesive 13 adhering to part of the surface of the wood chips 11 is impregnated into the wood chips 11, and therefore part of the adhesive 13 is impregnated into the surface layer of the wood chips 11, thereby improving the adhesion between the wood chips when the thermal storage board 10 is formed.

[0112] Here, for example, the heat storage material introducing step S3A may be performed using an agitator 90 shown in Fig. 12. Fig. 12 is an enlarged view of a main part of the agitator 90, which has a cylindrical housing 91 and an agitator rod 92 that is disposed inside the housing 91 and has a rotation axis along the axial direction of the housing 91. By rotating the agitator rod 92, the wood chips 11 supplied into the housing 91 can move axially as well as circumferentially (moving in a spiral).

[0113] The agitator 90 is provided with supply holes 93 that can individually supply the heat storage material 12 and the adhesive 13 to the wood chips 11 housed inside the housing 91. In this embodiment, a plurality of supply holes 93 (specifically, four, for example) are provided along the rotation axis of the agitator rod 92 (specifically, along the conveying direction).

[0114] 12, as an example, a plurality of supply holes 93, 93, ... are connected to supply sources (not shown) so that adhesive 13 and heat storage material 12 are alternately supplied to wood chips 11 being transported from the upstream side in the transport direction along the transport direction. Note that the agitator 90 may be provided with a temperature adjustment device (not shown) that adjusts the temperature of the wood chips 11, and the supply source (not shown) that supplies the heat storage material 12 may be provided with a heating device that heats the heat storage material 12.

[0115] For example, the temperature of the wood chips 11 may be adjusted by the temperature adjustment device described above so that the temperature of the wood chips 11 is below the temperature at which the thermal curing reaction of the adhesive 13 begins, but is equal to or higher than the temperature of the heat storage material 12 when the heat storage material 12 is applied (specifically, equal to or higher than the melting point of the latent heat storage material).In this case as well, the heat storage material 12, which has been heated by the heating device described above until the latent heat storage material melts, is applied to the wood chips 11 in a temperature-adjusted state, and the heat storage material 12 is introduced into the conduit 11a.

[0116] 11(a) and 11(b), the wood chips 11 are heated to a temperature equal to or higher than the temperature at which the heat storage material 12 is applied (specifically, equal to or higher than the melting point of the latent heat storage material), using heat H2 from a temperature adjustment device (not shown). On the other hand, if the temperature of the wood chips 11 before application is too high (higher than the curing start temperature of the adhesive 13), the wood chips 11 are cooled with air or the like by the temperature adjustment device so that the temperature is equal to or higher than the temperature of the heat storage material 12 at the time of application (specifically, equal to or higher than the melting point of the latent heat storage material) and lower than the curing start temperature of the adhesive 13.

[0117] 12 is used to apply the heat storage material 12 and adhesive 13 to the wood chips 11, and in the heat storage material introduction step S3A, the application of the adhesive 13 and the application of the heat storage material 12 can be repeated alternately. By alternately repeating the application of the adhesive 13 and the application of the heat storage material 12, the heat storage material 12 can be introduced into the conduit while preventing the adhesive 13 from seeping excessively into the wood chips 11 in a single application. Furthermore, since the wood chips 11 are transported in the transport direction while being stirred together with the heat storage material 12 and adhesive 13, the adhesive 13 can be applied more uniformly to the surfaces of the wood chips 11.

[0118] In this way, the wood chips 11 with the heat storage material 12 introduced into the conduits 11a are used to carry out the mat preparation step S5 and the board formation step S6 in the same manner as described in the first aspect of the invention. In the mat preparation step S5, as shown in the explanation of Fig. 2D above, a forming mat 10' is prepared from the wood chips 11 with the heat storage material 12 introduced, and in the board formation step S6, the forming mat 10' is heated and pressed to form the heat storage board 10.

[0119] As described above, when a mixture of a latent heat storage material and a room-temperature curing resin is used as the heat storage material 12, it is preferable to maintain the latent heat storage material of the mixture impregnated into the wood chips 11 in a molten state from the heat storage material introduction step S3A until the board molding step S6 is completed. After that, after the board molding step S6 is completed, the hardening of the room-temperature curing resin is completed while the latent heat storage material is in a molten state. Thereafter, the heat storage board 10 is allowed to cool, thereby solidifying the latent heat storage material.

[0120] After the board forming step S6 is completed, the room temperature curing resin hardens, forming a fine three-dimensional network structure, and the latent heat storage material is held and solidified within the three-dimensional network structure. As a result, it is possible to prevent the latent heat storage material from seeping out of the mixture.

[0121] Second Embodiment Below, a method for manufacturing a thermal storage board 10 according to a second embodiment of the second invention will be described with reference to Fig. 13 and the already described Figs. 4A, 4B, etc. Fig. 13 is a flow diagram for explaining a method for manufacturing a thermal storage board according to a second embodiment of the second invention. This embodiment differs from the manufacturing method according to the first embodiment of the second invention in that a water application step S70 is newly provided, which is similar to the content described in the second embodiment of the first invention. Therefore, a description of the common points will be omitted, and the content will be described briefly below.

[0122] In this embodiment, after the heat storage material introducing step S3A and before the board forming step S6, water is applied to the wood chips 11. Specifically, as shown in Fig. 13, after the heat storage material introducing step S3A and before the mat making step S5, water WB is applied to the wood chips 11.

[0123] As already explained with reference to FIG. 4A, the heat storage material 12 is introduced into the conduit 11a, and water WB is applied to the wood chips 11 with the adhesive 13 attached to the surface. This allows the water WB to adhere to the surface of the wood chips 11. When applying the water WB, water WB (specifically, hot water) heated to a temperature higher than the phase change temperature of the latent heat storage material of the heat storage material 12 may be applied. Applying water in this manner can prevent the latent heat storage material from locally solidifying and precipitating (or segregating if it is a mixture) before the heat storage board 10 is formed. This ensures that the latent heat storage material is dispersed inside the wood chips 11.

[0124] Alternatively, as explained in the embodiment of the first invention, water may be applied to the surface of the wood chips 11 that form the surface of the forming mat 10'. In this case, water may be applied to the wood chips 11 that are stacked in the stage of producing the forming mat 10', or the wood chips 11 that form the surface of the forming mat 10' (wood chips with heat storage material introduced) may be prepared in advance, and water may be applied to them before producing the forming mat 10'.

[0125] The same effects as those described in the second embodiment of the first invention can be expected. More simply stated, they are as follows. After the application of water, the mat is prepared in the mat preparation step S5, and then in the board formation step S6, the applied water turns into steam S due to the heat from the base 61 and the pressing member 62 (see FIG. 4B). This steam S can force the thermal storage material 12 introduced into the conduit 11a into the interior of the conduit 11a. Furthermore, in the board formation step S6, the pressure of the steam S adhering to the surface of the wood chips 11 can prevent the latent heat storage material from seeping out from the surface of the thermal storage board 10 during heat and pressure. Furthermore, if the adhesive 13 is an isocyanate adhesive, the steam flowing inside can promote hardening.

[0126] Third Embodiment Below, a method for manufacturing a thermal storage board 10 according to a third embodiment of the second invention will be described with reference to Fig. 14 and the already described Figs. 6A, 6B, etc. Fig. 14 is a flow diagram for explaining a method for manufacturing a thermal storage board 10 according to a third embodiment of the second invention. This embodiment differs from the manufacturing method according to the first embodiment of the second invention in that first and second wood chips 11A, 11B are used for the thermal storage board 10. Therefore, detailed description of the same steps as in the second embodiment will be omitted below, and only the differences will be described.

[0127] In this embodiment, as shown in FIG. 6B, a thermal storage board 10 is manufactured that includes a pair of surface layers 10A, 10C arranged on both sides and an internal layer 10B arranged between the pair of surface layers 10A, 10C.

[0128] As in the second embodiment of the first invention, in this embodiment, a pair of surface layers 10A, 10C are formed to sandwich the inner layer 10B from both sides of the inner layer 10B. The first wood chips 11A, which form the base material of each surface layer 10A (10C), are bonded to each other in each surface layer 10A (10C) using a first adhesive. The second wood chips 11B are bonded to each other in the inner layer 10B using a second adhesive. The surface layer 10A (10C) and the inner layer 10B contain a heat storage material, and the amount of heat storage material contained per unit weight of the second wood chips 11B in the inner layer 10B is greater than the amount of heat storage material contained per unit weight of the first wood chips 11A in the surface layer 10A (10C).

[0129] The following describes a method for manufacturing the thermal storage board 10. Note that the order of the steps for the first and second wood chips is not particularly limited, as long as the steps from the first chip production step S11 to the first thermal storage material introduction step S13A shown below are in order, and the steps from the second chip production step S21 to the second thermal storage material introduction step S23A are in order.

[0130] First, in the first chip production step S11, first wood chips 11A that will form the surface layer 10A are produced, and then in the second chip production step S21, second wood chips 11B that are larger than the first wood chips 11A and will form the inner layer 10B are produced. The sizes of the first wood chips 11A and the second wood chips 11B can be set as already explained in the third embodiment of the first invention.

[0131] Next, in a first chip moisture removal step S12, moisture is removed from the conduits 11a derived from the wood of the first wood chips 11A, and in a second chip moisture removal step S22, moisture is removed from the conduits 11a derived from the wood of the second wood chips 11B. The moisture removal is performed in the same manner as described in the first embodiment of the first invention, as shown in Fig. 2A etc.

[0132] Next, in the first heat storage material introduction step S13A, the moisture-removed first wood chips 11A are coated with a heat storage material 12 containing a molten latent heat storage material and an adhesive (first adhesive) 13. At this time, application conditions and the like are set so that the adhesive (first adhesive) 13 adheres to the first wood chips 11A so that a portion of the surface of the first wood chips 11A is exposed, and the heat storage material 12 is introduced into the conduit 11a from the exposed surface of the first wood chips 11A.

[0133] Similarly, in the second heat storage material introduction step S23A, the heat storage material 12 containing a molten latent heat storage material and an adhesive (second adhesive) 13 are applied to the second wood chips 11B from which moisture has been removed. At this time, application conditions and the like are set so that the adhesive (second adhesive) 13 is applied to at least the second wood chips 11B so that a portion of the surface of the second wood chips 11B is exposed, and the heat storage material 12 is introduced into the conduit 11a from the exposed surface of the second wood chips 11B. The method of applying the heat storage material 12 and adhesive 13 is the same as that described in the first embodiment, as shown in Figures 11 and 12, etc.

[0134] As with the third embodiment of the first invention, in this embodiment, the heat storage material 12 and adhesives 13 are applied to the first and second wood chips 11A, 11B so that the amount of heat storage material 12 introduced per unit weight is greater in the second wood chips 11B than in the first wood chips 11A. This allows the amount of heat storage material 12 introduced per unit weight to be greater in the second wood chips 11B than in the first wood chips 11A. This improves the heat storage capacity of the inner layer 10B of the heat storage board 10, and makes it more difficult for the latent heat storage material to seep out of the first wood chips 11A that make up the surface layers 10A, 10C of the heat storage board 10.

[0135] The first adhesive and the second adhesive may be the same adhesive, and are not particularly limited, and may be the same adhesive as the adhesive exemplified in the third embodiment of the first invention. The heat storage material applied to the first wood chips 11A and the second wood chips 11B is the same, but may be different from the heat storage materials exemplified above.

[0136] Next, a mat preparation step S5 is performed. Specifically, as shown in Fig. 14 and Fig. 6A(a), in a first surface layer formation step S51, a first surface layer mat 10a corresponding to the surface layer 10A is formed on a base 61. Next, as shown in Fig. 14 and Fig. 6A(b), an inner layer mat 10b corresponding to the inner layer 10B is laminated on the first surface layer mat 10a corresponding to the surface layer 10A.

[0137] Finally, as shown in Figure 14 and Figure 6A(c), a second surface layer mat 10c corresponding to the surface layer 10C is laminated on the inner layer mat 10b. The second surface layer mat 10c uses the first wood chips 11A to which the first adhesive has been applied in the first adhesive application step S14.

[0138] In this way, the forming mat 10' can be produced. The forming mat 10' is subjected to the board forming step S6 in the same manner as in the first embodiment. As a result, the heat storage board 10 shown in Fig. 6B can be obtained.

[0139] [Fourth embodiment] Below, a method for manufacturing a thermal storage board 10 according to a fourth embodiment of the second invention will be described with reference to Fig. 15 and Fig. 8, which has already been described. Fig. 15 is a part of a flow diagram for explaining a method for manufacturing a thermal storage board according to a fourth embodiment of the second invention, and is a flow diagram for explaining details of the mat manufacturing step S5. This embodiment differs from the manufacturing method according to the third embodiment in that first to third water application steps S71 to S73 are newly performed in the mat manufacturing step S5. Therefore, detailed explanations of steps similar to those in the third embodiment will be omitted, and only the differences will be explained below.

[0140] In this embodiment, as shown in Figures 15 and 8(a), a first water application step S71 is performed after the first surface layer formation step S51. In this step, water WB is applied to the first surface layer mat 10a, which corresponds to the surface layer 10A on which the base 61 is arranged, using a spray nozzle 41 or the like. The application of water WB is performed in the same manner as the water application step S70 shown in Figure 3.

[0141] 15 and 8(b), after the inner layer forming step S52, a second water applying step S72 is performed. In this step, water WB is applied to the inner layer mat 10b using a spray nozzle 41 or the like.

[0142] 14 and 8(c), the second surface layer forming step S53 is followed by a third water application step S73. In this step, water WB is applied to the second surface layer mat 10c using a spray nozzle 41 or the like. The water WB is applied to the first and second wood chips 11A, 11B so that the amount of water WB applied per unit weight is greater for the first wood chips 11A of the first and second surface layer mats 10a, 10c than for the second wood chips 11B of the inner layer mat 10b.

[0143] In this way, in the board forming step S6, the water contained in the surface layers 10A, 10C of the thermal storage board 10 evaporates and the resulting steam is sent to the internal layer 10B, which has larger voids than the surface layers 10A, 10C, and flows out from the side of the thermal storage board 10. This flow of water vapor can prevent the latent heat storage material from seeping out from the surface of the thermal storage board 10.

[0144] In this embodiment, the first to third water application steps S71 to S73 are performed in the mat fabrication step S5. However, for example, as in a modified example shown in Fig. 16, a first water application step S70A may be performed after the first heat storage material introduction step S13A and before the mat fabrication step S5 to apply water to the first wood chips 11A, and a second water application step S70B may be performed after the second heat storage material introduction step S23A and before the mat fabrication step S5 to apply water to the second wood chips 11B.

[0145] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made within the scope of the spirit of the present invention as set forth in the claims. [Explanation of symbols]

[0146] 10: heat storage board, 10A, 10C: surface layer, 10B: inner layer, 10': forming mat, 11: wood chip, 11A: first wood chip, 11B: second wood chip, 11a: conduit, 12: heat storage material, 13: adhesive, WA: moisture, WB: water, S2: moisture removal process, S3, S3A: heat storage material introduction process, S4: adhesive application process, S5: mat production process, S6: board molding process

Claims

1. A manufacturing method for manufacturing a heat storage board having heat storage properties, a moisture removal step of heating the wood chips to remove moisture from the conduits of the wood chips derived from the wood; a heat storage material introduction step of applying a heat storage material containing a molten latent heat storage material to the wood chips from which the moisture has been removed and introducing the heat storage material into the conduit; an adhesive application step of applying an adhesive to the wood chips containing the heat storage material introduced into the conduit; a mat preparation step of preparing a forming mat from the wood chips coated with the adhesive; a board forming step of forming a thermal storage board by hot pressing the forming mat; A method for manufacturing a thermal storage board, comprising:

2. A manufacturing method for manufacturing a heat storage board having heat storage properties, a moisture removal step of heating the wood chips to remove moisture from the conduits of the wood chips derived from the wood; a heat storage material introduction process in which a heat storage material containing a molten latent heat storage material and an adhesive are applied to the wood chips from which the moisture has been removed, the adhesive is attached to the wood chips so that a portion of the surface of the wood chips is exposed, and the heat storage material is introduced into the conduit from the exposed surface of the wood chips; a mat preparation process for preparing a forming mat from the wood chips into which the heat storage material has been introduced; a board forming step of forming a thermal storage board by hot pressing the forming mat; A method for manufacturing a thermal storage board, comprising:

3. 3. The method for manufacturing a thermal storage board according to claim 2, wherein in the thermal storage material introducing step, the thermal storage material is heated so that the viscosity of the thermal storage material becomes lower than the viscosity of the adhesive.

4. 4. The method for manufacturing a thermal storage board according to claim 2, wherein in the thermal storage material introducing step, the application of the adhesive and the application of the thermal storage material are repeated alternately.

5. The method for manufacturing a heat storage board according to any one of claims 1 to 4, characterized in that in the heat storage material introduction step, the temperature of the wood chips is adjusted to a temperature equal to or higher than the temperature of the heat storage material when the heat storage material is applied, the heat storage material is applied to the wood chips in a temperature-adjusted state, and the heat storage material is introduced into the conduit.

6. The method for manufacturing a heat storage board according to any one of claims 1 to 5, characterized in that water is applied to the wood chips after the heat storage material introducing step and before the board forming step.

7. The method for manufacturing a thermal storage board according to claim 6, wherein the water is heated to a temperature higher than the phase change temperature of the latent heat storage material.

8. 8. The method for manufacturing a thermal storage board according to claim 6 or 7, wherein the water is applied to wood chips that form the surface of the forming mat.

9. The method for manufacturing a thermal storage board is a method for manufacturing a thermal storage board including a pair of surface layers disposed on both sides and an internal layer disposed between the pair of surface layers, In the moisture removal step, moisture is removed from the first wood chips constituting the surface layer and the second wood chips larger than the first wood chips and constituting the inner layer, In the heat storage material introduction step, the heat storage material is applied to the first and second wood chips so that the amount of heat storage material introduced per unit weight of the second wood chips is greater than that of the first wood chips; A method for manufacturing a heat storage board as described in claim 6 or 7, characterized in that when applying the water, the water is applied to the first and second wood chips so that the amount of water applied per unit weight is greater for the first wood chips than for the second wood chips.

10. the heat storage material is a mixture of the latent heat storage material and a room temperature curing resin, During the period from the heat storage material introduction step to the completion of the board forming step, the latent heat storage material of the mixture impregnated into the wood chips is maintained in a molten state, The method for manufacturing a heat storage board according to any one of claims 1 to 9, characterized in that after the board molding process is completed, the latent heat storage material is in a molten state, and the hardening of the room temperature curing resin is completed.

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