Method for producing fiberboard and compressed biomass for producing fiberboard

Abstract

Provided is a method for manufacturing a fiber board with which it is possible to easily produce a board having stable quality even when a palm plant having low bulk density is used. An adhesive is added to woody fibers obtained by steaming and fibrillating a woody material. Then, forming and heat press molding are performed. The woody material contains a compressed material obtained by compressing and integrating pulverized materials of a plurality of dried palm plants.

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a fiberboard and a compressed biomass product for producing a fiberboard. More particularly, the present disclosure relates to a method for producing a fiberboard using a wood material and a compressed biomass product for producing a fiberboard. [Background technology]

[0002] Patent Document 1 describes a method for manufacturing a wood fiberboard. In this manufacturing method, wood chips are steamed and defibrated to obtain wood fibers, which are then dried, and an isocyanate adhesive is added to the wood fibers, which are then foamed and hot pressed. Starches are added to the wood chips before or during the steaming process. Tropical wood chips are used as the wood chips.

[0003] However, in recent years, tropical wood has been in decline on a global scale, and as an alternative, Patent Document 2 proposes a fiberboard using wood fibers obtained from oil palm. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-052514 A [Patent Document 2] JP 2018-069670 A Summary of the Invention

[0005] However, when the manufacturing method described in Patent Document 1 is applied to palm plants, there is a problem in that productivity decreases because palm plants are materials with poor storage properties and low bulk density after drying.

[0006] An object of the present disclosure is to provide a fiber board manufacturing method and compressed biomass product for manufacturing fiber board that are highly productive even when using palm plants, which are materials with poor storage properties and low bulk density after drying.

[0007] In one embodiment of the present disclosure, a fiberboard is manufactured by steaming and defibrating a wood material to obtain wood fibers, adding an adhesive to the wood fibers, and then forming and thermo-compressing the wood material. The wood material includes a compressed material obtained by compressing and integrating dried crushed materials of multiple palm family plants.

[0008] The compressed biomass material for fiber board production according to one embodiment of the present disclosure is a compressed material obtained by integrating dried pulverized materials of a plurality of palm family plants. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment) (1) Overview Hereinafter, the process leading to the method for producing a fiber board and the compressed biomass material for producing a fiber board according to this embodiment will be described.

[0010] The current global market for wood boards is worth over 10 trillion yen per year, and in parallel with the growing concern of global environmental issues, further market expansion and demand are expected in the future. Accordingly, there is an increasing need for technology to utilize alternative materials, as the traditionally used tropical woods such as lauan and softwoods such as cedar are exhaustible resources that require more than 30 years to grow.

[0011] There are various types of wood boards, including laminated wood, which is mainly used for structural materials and formwork, chipboard, which is used for underlayment and as a furniture material, and fiberboard, which is widely used for interior materials and the surface finish of furniture. Technologies for using low-quality wood such as small diameter trees and fast-growing plantation trees with short felling periods have been developed as alternative materials to these exhaustible resources for wood boards, and are currently in widespread use around the world. However, with further increases in usage and a decrease in the global area of ​​afforestation, it is thought that these materials will gradually become more difficult to procure.

[0012] In particular, fiberboards can be manufactured using only fibrous materials, not pieces of wood of a certain shape, and so in the past many efforts have been made to utilize plants from the grass family, such as bamboo, straw, and bagasse, which have strong bast fibers, as well as plants from the mallow family, such as kenaf and jute, as future material technologies.However, these have not been widely put to practical use due to issues in terms of quality, manufacturing, and raw material procurement.

[0013] In this context, palm plants such as oil palm and coconut palm, which are widely distributed mainly in tropical regions, are attracting attention as a material with a large accumulation as a raw material. In particular, with the growth of the palm oil industry, large amounts of trunk parts (Oil Palm Trunk: OPT) and fruit bunch parts (Empty Fiber Bulk: EFB) of oil palm are discarded, and in Malaysia, one of the palm oil producing countries, more than 50 million tons are discarded annually. Furthermore, if these are left unattended, more than 1 million tons of methane gas is released annually. When converted into carbon dioxide emissions, this amounts to approximately 10% of the country's carbon dioxide emissions, and is currently an extremely serious social issue.

[0014] The annual global use of fiberboard is 150 million tons, so even just the 50 million tons that are discarded is an extremely large accumulation, accounting for about one-third of the world's total. However, palm plants have a moisture content of about 70-300%, more than twice that of normal tropical wood, meaning that green wood will rot within one to two weeks, making storage extremely difficult.

[0015] Furthermore, the apparent specific gravity of a typical palm plant in its green state is about 0.60 to 0.80, but after drying, the specific gravity is about 0.35. Therefore, when transporting green timber, the amount of material obtained is about half of the mass actually transported, which is an issue. Also, when drying on-site, the bulk density becomes too low during transportation, which increases the number of transports, which is an issue that reduces transportation efficiency.

[0016] In addition, although the fibers of palm plants are rigid, they contain approximately 40% by mass of fine powder with a diameter of less than 0.5 mm called parenchyma cells.When fiberboards are usually manufactured using conventional methods using palm plants as raw materials, not only do these fine powders cause reduced board productivity during board manufacturing, such as clogging of blades, poor drying, and quality variations, but they also do not contribute to the development of strength, making it difficult to ensure the strength performance of the fiberboard.

[0017] Due to the issues mentioned above, palm plants have hardly been put to practical use for fiberboard applications, and currently most oil palm waste is left abandoned and disposed of locally, which remains a social issue.

[0018] Therefore, in this embodiment, even when using palm plant waste materials, which have poor storage properties and low bulk density after drying, as raw materials, it is possible to produce fiberboards with high productivity. At the same time, it is possible to provide fiberboards that can be used as an alternative to fiberboards in the global market in the future, thereby stabilizing procurement and helping to solve social issues in Southeast Asia.

[0019] That is, in the method for producing a fiberboard according to the present embodiment, a wood material is steamed and defibrated to obtain wood fibers, to which an adhesive is added, and then the wood material is formed and thermo-compressed. The wood material includes a compressed material obtained by compressing and integrating dried crushed materials of multiple palm family plants.

[0020] In this way, the method for producing a fiberboard according to the present embodiment uses a compressed biomass product obtained by compressing and integrating the dried pulverized material of multiple palm family plants. Since the fiberboard is produced using the compressed biomass product, whose fiber tissue is not easily damaged and does not easily decay, even when the raw material is a palm family plant, which is a waste material with poor storage properties and low bulk density after drying, a fiberboard having excellent strength and other practical properties can be easily and productively produced.

[0021] (2) Details <Compressed biomass for fiberboard manufacturing> The compressed biomass for fiberboard production according to this embodiment is a compressed product of dried pulverized material of multiple palm family plants. That is, coconut cuttings and crushed pieces, which are pulverized material of palm family plants, are used as raw materials, and after drying, multiple pieces are compressed together to obtain a compressed biomass product composed of renewable biological resources (palm family plants). The compressed biomass for fiberboard production (hereinafter sometimes simply referred to as "compressed biomass product") has improved transportability and improved productivity compared to the case where the pulverized material of palm family plants is not compressed. In addition, since dried pulverized material is used, the progression of decay is prevented, the material yield rate can be increased, and productivity is improved.

[0022] The type of palm plant used for the compressed biomass is not particularly limited, but it can be oil palm, bougainvillea, coconut palm, date palm, sago palm, acai, palm, etc. Also, the parts that can be used are not particularly limited, but can be trunk, leaves, fruit, bunch, seeds, etc.

[0023] Palm plants are crushed and dried, and then compressed. The order of crushing and drying may be any, or they may be performed simultaneously. The method of crushing palm plants is not particularly limited, but may be performed, for example, using a chipper. Drying the crushed material to a moisture content of 25% by mass or less is preferable because it can prevent the progression of decay. After crushing the palm plants, it is preferable to wash them with water to reduce the amount of ash, since this can reduce the occurrence of process troubles due to ash in the steaming process described below.

[0024] The ground material of a palm family plant is an aggregate of fibrous materials (including powdered materials) obtained by grinding the above-mentioned usable parts of a palm family plant. The ground material of a palm family plant preferably contains vascular tissue of a palm family plant. Vascular tissue of a palm family plant is tissue that transports water and nutrients necessary for the growth of a palm family plant, and contains xylem and phloem. Xylem is a transport path for water and nutrients absorbed from the roots, and contains vessels and tracheids. Phloem is a transport path for nutrients created by the leaves, and contains phloem tubes.

[0025] The length of the pulverized material of the palm family plant is preferably within the range of 0.8 mm to 50.0 mm, and the diameter is preferably within the range of 0.10 mm to 2.00 mm. If the length of the pulverized material is shorter than 0.8 mm or the diameter of the pulverized material is smaller than 0.10 mm, the vascular tissue of the palm family plant contained in the pulverized material according to this embodiment becomes too fine, and the strength of the fiber board is likely to decrease. If the length of the pulverized material is longer than 50.0 mm or the diameter of the pulverized material is larger than 2.00 mm, the fiber shape of the wood fibers constituting the fiber board according to this embodiment, which will be described later, becomes too coarse, and the surface smoothness of the fiber board is likely to decrease. In addition, in this disclosure, "diameter" means diameter.

[0026] The length of the palm pulverized material is more preferably within the range of 5.0 mm or more and 40.0 mm or less, and the diameter is more preferably within the range of 0.3 mm or more and 2.00 mm or less.

[0027] The length and diameter of the palm family crushed material are obtained by photographing a predetermined amount of crushed material or observing it with a magnifying glass and measuring the length and diameter.

[0028] The crushed material having a length of 0.8 mm or more and a diameter of 0.10 mm or more and 2.00 mm or less is preferably contained in a mass ratio of 70% or more of the total amount of the crushed material of the palm family plant. If this mass ratio is lower than 70%, the fiber components contributing to the strength expression of the fiber board of this embodiment will be reduced, and the strength of the fiber board will be easily reduced. In addition, since the ratio of the parenchyma cell tissue of the palm family plant, which is the main component of the fine powder, is increased in the crushed material of the palm family plant, it may be difficult to stably produce the fiber board because the blade clogging, poor drying, quality variation, etc. are likely to occur. It is more preferable that the crushed material of the palm family plant having a length of 0.8 mm or more and a diameter of 0.10 mm or more and 2.00 mm or less is contained in a mass ratio of 80% or more of the total amount of the crushed material of the palm family plant, and most preferably 100%.

[0029] The crushed material of a palm family plant is preferably a palm family plant crushed and then classified to reduce the amount of palm family plant parenchyma tissue. In other words, the crushed material of a palm family plant contains small crushed material mainly composed of palm family plant parenchyma tissue and large crushed material mainly composed of palm family plant vascular tissue, and is preferably a palm family plant crushed by reducing the amount of the small crushed material. Palm family plant parenchyma tissue is a tissue composed of palm family plant parenchyma cells. Palm family plant parenchyma tissue contains assimilation tissue, secretion tissue, storage tissue, etc., and has physiological functions such as synthesis, decomposition, and storage.

[0030] If the palm family plant parenchyma tissue is contained in a large amount in the pulverized product of the palm family plant, it may be difficult to stably produce a fiberboard because the palm family plant parenchyma tissue is a fine powder. Therefore, in this embodiment, the palm family plant parenchyma tissue is reduced in weight to obtain a pulverized product of the palm family plant with a low content of the palm family plant parenchyma tissue. As a method for reducing the weight of the palm family plant parenchyma tissue, a method of removing small sized pulverized products by classification can be adopted. For classification, a method such as sieving, wind sorting, water bathing, etc. can be considered, but is not particularly limited.

[0031] The biomass compressed product according to this embodiment is obtained by compressing and integrating a plurality of dried pulverized materials. That is, the biomass compressed product according to this embodiment is a compressed product that includes dried pulverized materials of a plurality of palm plants (biomass) and is an integrated pulverized material. The shape of the biomass compressed product may be, but is not limited to, a tablet, pellet, tablet, briquette, block, plate, or the like. The biomass compressed product is compressed and integrated into a predetermined shape by a compression molding machine such as a pelletizer. When compressing the pulverized material, no adhesive is used, and the material is integrated by compression force, but an adhesive may be used to the extent that it does not interfere with the defibration of the wood material. In addition, the pulverized material may be mixed with a material having functionality such as an antibacterial agent, an aromatic agent, or a colorant to integrate the material. In this case, the obtained fiber board can be given these functions, which is preferable.

[0032] The specific gravity of the compressed biomass product is preferably in the range of 0.35 to 1.50. If the specific gravity of the compressed biomass product is less than 0.35, the mechanical durability of the compressed biomass product is reduced, and the compressed biomass product is likely to be crushed or broken during transportation. If the specific gravity of the compressed biomass product is greater than 1.50, the fiber tissue constituting the pulverized material of the palm family plant may be compressed and damaged, and the strength characteristics of the finally obtained fiber board are likely to be reduced. The specific gravity of the compressed biomass product is more preferably in the range of 0.40 to 1.50. If it is less than 0.40, the bulk density becomes high, and the volume rate becomes the limiting factor during transportation, so the number of round trips during transportation increases. For this reason, the specific gravity of the compressed biomass product is preferably in the range of 0.40 to 1.50.

[0033] The compressed biomass product preferably has a moisture content of 25% by mass or less, more preferably 20% by mass or less. If the moisture content is higher than 25% by mass, the compressed biomass product is likely to be less able to maintain its shape and is more likely to spoil, which means that its storage properties are also likely to be reduced.

[0034] Thus, when the compressed biomass product of this embodiment has a specific gravity in the range of 0.35 to 1.50, storage properties and mechanical durability are improved, and the fibrous tissue of the palm plant is less likely to be damaged by compression. Furthermore, when the compressed biomass product of this embodiment has a moisture content of 25% by mass or less, it is less likely to decay and storage properties are improved. Note that "mechanical durability" in this disclosure refers to shape retention, and refers to the property of being less likely to crumble or break during storage.

[0035] <Manufacturing method of fiberboard> In the method for producing a fiberboard according to the present embodiment, a wood material is steamed and defibrated to obtain wood fibers, and then an adhesive is added to the wood fibers, followed by forming and thermo-compression molding. The compressed biomass product according to the present embodiment is used as the wood material. In the method for producing a fiberboard according to the present embodiment, by using the compressed biomass product, boards of stable quality can be easily produced even when palm plants with low bulk density are used. As the wood material, the compressed biomass product alone may be used, or the compressed biomass product may be used in combination with crushed material of tropical wood or coniferous trees that have been conventionally used in the production of medium density fiberboards.

[0036] In the steaming process, wood material (compressed biomass) is treated with high-temperature, high-pressure saturated steam. The steaming conditions are not particularly limited, but may be, for example, a temperature of 150 to 200°C, a pressure of 0.5 to 2.0 MPa, and a time of 1 to 15 minutes. Steaming is carried out using a digester or the like.

[0037] Defibration is a process that breaks down wood materials (compressed biomass) into wood fibers (mainly vascular tissue of palm plants). Defibration involves processing wood materials after steaming using a refiner or similar device.

[0038] After defibration, drying is performed as necessary. Drying is a process for reducing the moisture content of the defibrated wood fibers. Drying can be performed by supplying hot air to the defibrated wood fibers. The moisture content of the wood fibers after drying is not particularly limited, but it is preferable that the moisture content is, for example, 20 mass% or less with respect to the total amount of the wood fibers after bone drying. The drying may be performed after adding an adhesive to the wood fibers, before adding an adhesive to the wood fibers, while adding an adhesive to the wood fibers, or by adding an adhesive to the wood fibers, drying the fibers, and adding an adhesive again.

[0039] The adhesive added to the wood fibers is used as a binder that hardens to bond the wood fibers. The adhesive is a synthetic resin adhesive that is liquid at room temperature and hardens when heated, such as an adhesive containing diphenylmethane diisocyanate or an adhesive containing urea-melamine.

[0040] The wood fibers with the adhesive added thereto are formed into a desired shape, for example into a mat.

[0041] The wood fibers to which the adhesive has been added are formed and then thermocompressed. That is, the wood fibers formed into a plate shape or the like are heated and pressurized. The thermocompression molding can be performed, for example, by pressing the wood fibers between a pair of hot plates. The thermocompression molding conditions are not particularly limited, but the molding temperature is, for example, in the range of 140°C to 230°C. The molding time is, for example, in the range of 10 seconds to 3 minutes. The molding pressure is, for example, in the range of 0.5 MPa to 4 MPa. The adhesive added to the wood fibers is hardened by such thermocompression molding, and the wood fibers are bonded to each other, thereby producing the fiber board of this embodiment. The fiber board can be widely used, for example, in building materials, furniture, and residential interiors.

[0042] The equipment for the processes of steaming, defibrating, adding adhesive, forming, hot pressing, etc. can be the same as that used for the conventional manufacture of medium density fiberboards, which increases the efficiency of equipment use, and makes it possible to obtain fiberboards with excellent productivity even when using palm plant waste, which has poor storage properties and low bulk density after drying, as the raw material. EXAMPLES

[0043] Example 1 As shown in Table 1, the trunk part (OPT) of oil palm was taken out as the raw material for fiberboard, and was put into a chipper to obtain palm plant pulverized material of 30 mm to 40 mm square. Then, foreign matter was removed using a foreign matter remover, and the material was put into a wet grinder and dried to a specified moisture content using a rotary kiln after grinding. Then, the material was sieved through an 8.6 mesh sieve and then through a 200 mesh sieve to classify it and reduce the palm plant parenchyma tissue ratio, thereby obtaining palm plant pulverized material of average length 21.4 mm and average diameter 1.08 mm. This pulverized material contained 83% by mass of pulverized material with a length of 0.8 mm to 50.0 mm and a diameter of 0.10 mm to 2.00 mm (hereinafter, pulverized material in this range will be referred to as "large size pulverized material"). The average length and average diameter of the palm family crushed materials are obtained by measuring the length and diameter of each crushed material with a magnifying glass for a given amount of crushed material and calculating the arithmetic mean. The mass ratio of the large size crushed materials is obtained by measuring the length and diameter of a given amount of crushed material with a magnifying glass, classifying the materials according to whether or not the length is within the range of 0.8 mm to 50.0 mm and the diameter is within the range of 0.10 mm to 2.00 mm, and calculating the mass ratio of the materials within this range to those not within this range.

[0044] The obtained palm plant powder was used as a raw material and compressed into cylindrical pellets with a diameter of 15 mm and a length of 40 mm using a pelletizer, resulting in a compressed biomass product with a specific gravity of 0.61 and a moisture content of 9 mass%.

[0045] These compressed biomass materials were fed into a pressurized refiner, steamed at 170°C for 5 minutes, defibrated, and dried in a jet dryer at 200°C to produce dry fiber (wood fiber).

[0046] Diphenylmethane diisocyanate (MDI) was dispersed and applied at 5% by mass as a binder to the dried fiber, and then molded at 180°C for 90 seconds to produce a sheet with a thickness of 3 mm and a density of 800 kg / m 3 As a result, a fiberboard of

[0047] Example 2 Oil palm bunches (EFB) were used as the raw material for the fiberboard, and a palm plant pulverized material with an average length of 32.5 mm, an average diameter of 0.30 mm, and a large-size pulverized material content of 92% by mass was produced in the same process as in Example 1. Thereafter, a tablet forming machine was used to compress the palm plant pulverized material, producing tablets with a diameter of 10 mm and a thickness of 5 mm, thereby obtaining a compressed biomass material with a specific gravity of 1.00 and a moisture content of 12% by mass. A fiberboard was produced in the same manner as in Example 1, except that such a compressed biomass material was used.

[0048] Example 3 The trunk of a coconut palm was used as the raw material for the fiberboard, and a crushed palm plant with an average length of 7.8 mm, an average diameter of 1.87 mm, and a large-sized crushed material content of 75% by mass was produced in the same process as in Example 1. Thereafter, a briquette was used to compress the crushed palm plant, and a cylindrical briquette with a diameter of 80 mm and a length of 150 mm was produced to obtain a compressed biomass product with a specific gravity of 1.35 and a moisture content of 19% by mass. A fiberboard was produced in the same manner as in Example 1, except that such a compressed biomass product was used.

[0049] Example 4 Oil palm trunks (OPT) were used as the raw material for the fiberboard, and a palm plant pulverized product with an average length of 40.6 mm, an average diameter of 0.30 mm, and a large-size pulverized product content of 92% by mass was produced in the same process as in Example 1. Thereafter, a three-axis volume reducer was used to compress the palm plant pulverized product, producing a 100 mm square block-shaped compressed product, yielding a biomass compressed product with a specific gravity of 0.40 and a moisture content of 9% by mass. A fiberboard was produced in the same manner as in Example 1, except that such a biomass compressed product was used.

[0050] Example 5 Oil palm bunches (EFB) were used as the raw material for the fiberboard, and a palm plant pulverized product with an average length of 15.6 mm, an average diameter of 0.79 mm, and a large-sized pulverized product content of 70% by mass was produced in the same process as in Example 1. Thereafter, a roller compactor was used to compress the palm plant pulverized product, producing a plate-shaped compressed product with a width of 120 mm, a length of 200 mm, and a thickness of 5 mm, to obtain a compressed biomass product with a specific gravity of 1.22 and a moisture content of 15% by mass. A fiberboard was produced in the same manner as in Example 1, except that such a compressed biomass product was used.

[0051] Example 6 A fiber board was obtained in the same manner as in Example 1, except that the specific gravity of the compressed biomass product in the pellet shape was set to 0.30. The content of large pulverized material in the compressed biomass product was 83% by mass.

[0052] Example 7 A fiber board was obtained in the same manner as in Example 1, except that when preparing the pellet-shaped compressed biomass product, the specific gravity of the compressed product was set to 1.55.

[0053] Example 8 A fiber board was obtained in the same manner as in Example 1, except that when preparing the pellet-shaped compressed biomass product, the moisture content of the compressed product was set to 27 mass %.

[0054] Example 9 A fiberboard was obtained in the same manner as in Example 4, except that when creating the block-shaped biomass compressed material, crushed material of a palm family plant with an average length of 75.7 mm, an average diameter of 0.30 mm, and a large-size crushed material content of 65% by mass was used to create the biomass compressed material.

[0055] Example 10 A fiber board was obtained in the same manner as in Example 2, except that when creating the tablet-shaped biomass compressed product, crushed material of a palm family plant with an average length of 32.5 mm, an average diameter of 0.05 mm, and a large-size crushed material content of 63% by mass was used to create the biomass compressed product.

[0056] Example 11 A fiber board was obtained in the same manner as in Example 3, except that when creating the briquette-shaped biomass compressed material, crushed material of a palm plant with an average length of 10.3 mm, an average diameter of 1.92 mm, and a large-size crushed material content of 61 mass% was used to create the biomass compressed material.

[0057] Example 12 A fiberboard was obtained in the same manner as in Example 1, except that when creating the block-shaped biomass compressed material, crushed material of a palm family plant with an average length of 32.5 mm, an average diameter of 2.50 mm, and a large-size crushed material content of 65% by mass was used to create the biomass compressed material.

[0058] Example 13 A fiberboard was obtained in the same manner as in Example 1, except that when creating the block-shaped biomass compressed material, crushed material of a palm plant with an average length of 0.81 mm, an average diameter of 0.15 mm, and a large-size crushed material content of 60 mass% was used to create the biomass compressed material.

[0059] <Evaluation method> Mechanical durability evaluation The mechanical durability (DU) of the compressed biomass material after molding was measured based on the wood pellet quality standard of the Japan Wood Pellet Association. DU = (m1 / m0) x 100 (%) m0: Mass before test m1: Mass after test (judgement) A: 97.5% or more B: 96.5% or more but less than 97.5% C: Less than 96.5%

[0060] Storage evaluation The mold resistance of compressed biomass was measured based on the "JIS Z 2911 mold resistance test method." (judgement) A: 14 days or more B: 10 days or more but less than 14 days C: Less than 10 days

[0061] Strength evaluation Based on "JIS A 5905 Fiberboard", a bending test was conducted on the fiberboard to measure the bending strength. (judgement) A:25MPa or more B: Less than 25MPa, 20MPa or more C: Less than 20MPa Surface smoothness evaluation The center line average roughness Ra of the fiberboard was measured in accordance with "JIS B 0601 Surface Roughness." (judgement) A: 5μm or less B: greater than 5μm and less than 15μm C: Larger than 15 μm The results of each evaluation are shown in Table 2.

[0062] [Table 1]

[0063] [Table 2]

[0064] All of the examples were rated A or B, and it was confirmed that there was no problem with the practicality of the fiber boat and the manufacturing method thereof.

[0065] In particular, by comparing Example 1 and Example 6, it was confirmed that when the specific gravity of the compressed biomass product is low, the mechanical durability of the compressed biomass product is somewhat low and the compressed biomass product is easily broken during transportation or use.

[0066] By comparing Example 1 and Example 7, it was confirmed that when the specific gravity of the compressed biomass material is too high, the strength of the fiber board is likely to decrease.

[0067] By comparing Example 1 and Example 8, it was confirmed that when the moisture content of the compressed biomass product is too high, the storage properties of the compressed biomass product are likely to decrease.

[0068] By comparing Example 4 and Example 9, it was confirmed that when the average length of the pulverized material is large and the content of large-sized pulverized material is low, the surface smoothness of the fiberboard is likely to decrease.

[0069] By comparing Example 2 and Example 10, it was confirmed that when the average particle size of the pulverized material is small and the content of large-sized pulverized material is low, the strength of the fiber board is likely to decrease.

[0070] By comparing Example 3 and Example 11, it was confirmed that when the content of large-sized crushed material is low, the strength of the fiber board is likely to decrease.

[0071] According to Examples 9, 10, 12 and 13, the average length and average diameter of the pulverized particles and the content of large size pulverized particles are preferably within the above-mentioned specified ranges.

[0072] (summary) As described above, the method for producing a fiberboard according to the first aspect includes adding an adhesive to wood fibers obtained by steaming and defibrating a wood material, forming the wood fibers, and thermo-compressing the wood material. The wood material includes a compressed material obtained by compressing and integrating dried crushed materials of multiple palm family plants.

[0073] According to this embodiment, even when palm plants having low bulk density are used, fiberboards of stable quality can be easily produced. The storage property, which is an issue with palm plants, can be improved, and at the same time, transportability can be improved.

[0074] A second aspect is the method for producing a fiber board according to the first aspect, wherein the compressed product has a specific gravity of 0.35 to 1.50 and a moisture content of 25 mass % or less.

[0075] According to this embodiment, even when palm plants having low bulk density are used, fiberboards of stable quality can be easily produced. The storage property, which is an issue with palm plants, can be improved, and at the same time, transportability can be improved.

[0076] The third aspect is a method for producing a fiber board according to the first or second aspect, wherein the crushed material of the palm family plant is obtained by crushing the palm family plant and then classifying it to reduce the amount of parenchyma cell tissue of the palm family plant.

[0077] According to this embodiment, there is an advantage that finely powdered parenchymal tissue of palm family plants is less likely to be included in the wood material, making it easier to produce fiberboards stably.

[0078] A fourth aspect is a method for producing a fiber board according to any one of the first to third aspects, wherein the crushed material of the palm family plant contains crushed material having a length of 0.8 mm or more and 50.0 mm or less and a diameter of 0.10 mm or more and 2.00 mm or less at a mass ratio of 70% or more.

[0079] According to this embodiment, there is an advantage that a fiberboard of more stable quality can be easily produced.

[0080] The compressed biomass material for fiber board production according to the fifth embodiment is a compressed material obtained by integrating dried pulverized materials of a plurality of palm plants.

[0081] According to this aspect, by using the compressed biomass material for the production of fiber boards, fiber boards of stable quality can be easily produced even when palm plants with low bulk density are used. In addition, the storage property, which is an issue with palm plants, can be improved, and at the same time, transportability can be improved.

[0082] A sixth aspect is the compressed biomass material for fiber board production according to the fifth aspect, which has a specific gravity of 0.35 to 1.50 and a moisture content of 25 mass % or less.

[0083] According to this aspect, by using the compressed biomass material for the production of fiber boards, fiber boards of stable quality can be easily produced even when palm plants with low bulk density are used. In addition, the storage property, which is an issue with palm plants, can be improved, and at the same time, transportability can be improved.

[0084] A seventh aspect is a compressed biomass material for fiber board production according to the fifth or sixth aspect, wherein the crushed material of the palm family plant contains 70% or more by mass of crushed material having a length of 0.8 mm or more and 50.0 mm or less and a diameter of 0.10 mm or more and 2.00 mm or less.

[0085] According to this embodiment, there is an advantage that a fiberboard of more stable quality can be easily produced.

Claims

1. A method for producing a fiberboard in which a wood material is steamed and defibrated to obtain wood fibers, an adhesive is added to the wood fibers, and the wood fibers are then formed and thermo-compressed. The wood material includes a compressed material obtained by compressing and integrating dried crushed materials of a plurality of palm family plants, The compressed product contains 70% or more by mass of pulverized material of the palm family plant having a length of 0.8 mm or more and 50.0 mm or less and a diameter of 0.10 mm or more and 2.00 mm or less, The moisture content of the compressed product is 25% by mass or less. How fiberboard is manufactured.

2. The compressed product has a specific gravity of 0.35 or more and 1.50 or less. A method for producing the fiber board according to claim 1.

3. The pulverized material of the palm family plant is obtained by pulverizing the palm family plant and then classifying it to reduce the amount of parenchyma tissue of the palm family plant. A method for producing the fiber board according to claim 1 or 2.

4. The crushed material of the palm family plant contains crushed material having a length of 5.0 mm to 40.0 mm and a diameter of 0.3 mm to 2.00 mm in a mass ratio of 70% or more. The method for producing the fiber board according to any one of claims 1 to 3.

5. A compressed product obtained by integrating dried crushed materials of a plurality of palm family plants, The crushed material of the palm family plant contains crushed material having a length of 0.8 mm or more and 50.0 mm or less and a diameter of 0.10 mm or more and 2.00 mm or less in a mass ratio of 70% or more, The moisture content of the compressed product is 25% by mass or less. Compressed biomass for fiberboard production.

6. Specific gravity is 0.35 or more and 1.50 or less. The compressed biomass material for producing fiberboard according to claim 5.

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