Particleboard manufacturing method

Abstract

The present disclosure addresses the problem of providing a method for producing a particle board, the method being capable of producing a high-strength particle board. The method for producing a particle board according to the present disclosure includes a compression step, a fragmentation step, a forming step, and a thermal compression step. In the compression step, a pulverized product of Palmae plant is compressed to obtain a compressed material. In the fragmentation step, the compressed material is cut to obtain small pieces. In the forming step, a mat is obtained by adding an adhesive to the small pieces and forming. In the thermal compression step, the mat is compressed while being heated. The pulverized product contains chips having a length of 5.0 mm to 100.0 mm and an outer diameter of 1.0 mm to 10.0 mm. The content of the chips is at least 70 mass% with respect to the total mass of the pulverized product.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a particle board. In the law

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a wood board (such as a particle board). This method for manufacturing a wood board includes a forming step, a high-frequency preheating step, and a hot press step.

[0003] Here, in the forming step, wood materials such as chips mixed with an adhesive or defibrated fibers are spread to a certain thickness. In the high-frequency preheating step, the wood material spread to a certain thickness is heated by high-frequency dielectric heating. In the hot press step, the wood material preheated by high-frequency dielectric heating is heated to a certain high temperature and thermally pressed to a predetermined thickness.

[0004] However, in the method for manufacturing a wood board of Patent Document 1, when using palm family plants as raw materials, there is a problem that it is difficult to obtain a high-strength wood board.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] An object of the present disclosure is to provide a method for manufacturing a particle board that can manufacture a high-strength particle board when using palm family plants as raw materials. Law

[0007] ​​A method for manufacturing particleboard according to one aspect of the present disclosure includes a compression step, a fragmentation step, a forming step, and a hot-pressing step. In the compression step, crushed palm plants are compressed to obtain a compressed material. In the fragmentation step, small pieces are obtained by cutting the compressed material. In the forming step, an adhesive is added to the small pieces and formed to obtain a mat. In the hot-pressing step, the mat is heated and compressed. The crushed material contains chips with a length of 5.0 mm or more and 100.0 mm or less, and an outer diameter of 1.0 mm or more and 10.0 mm or less. The content of the chips is 70% by mass or more of the total mass of the crushed material.

[0008] A compressed material for manufacturing particleboard according to one aspect of this disclosure is a compressed material obtained by compressing pulverized palm plants. The pulverized material contains chips with a length of 5.0 mm or more and a length of 100.0 mm or less and an outer diameter of 1.0 mm or more and a diameter of 10.0 mm or less. The content of the chips is 70% by mass or more of the total mass of the pulverized material. [Modes for carrying out the invention]

[0009] 1. Overview As the palm oil industry grows, large quantities of oil palm trunks (OPT) and empty fiber bundles (EFB) are discarded. In Malaysia, one of the palm oil-producing countries, more than 50 million tons of this waste are generated annually. In addition, the release of methane gas from these discarded materials amounts to more than 1 million tons per year. When converted to carbon dioxide emissions, this accounts for approximately 10% of the country's total carbon dioxide emissions, making it an extremely serious social problem.

[0010] Furthermore, palm trees have a moisture content of approximately 70-300%, which is more than twice that of typical tropical hardwoods. As a result, green lumber milled from logs rots within 1-2 weeks, posing a significant problem in terms of storage. In addition, while the apparent specific gravity of green palm wood is around 0.60-0.80, its specific gravity drops to around 0.35 after drying. Therefore, when transporting green lumber from logging sites to processing facilities, the amount of usable material obtained is only about half of the actual mass transported. Moreover, if the wood is dried on-site, its bulk density becomes too low during transport, increasing the number of transport trips and reducing transport efficiency.

[0011] As one solution to environmental problems, the use of palm plants as building materials is being explored. However, as mentioned above, the method for manufacturing wood-based boards described in Patent Document 1 had the problem that it was difficult to obtain high-strength wood-based boards when palm plants were used as raw materials. The inventors of this invention believe that the reason for this is the low bulk density of palm plants.

[0012] Therefore, the inventors focused on particleboard and diligently conducted research to resolve the above-mentioned issues. As a result, they developed the following manufacturing method that can produce high-strength particleboard by using palm plants as raw materials and adding an extra step to the conventional particleboard manufacturing method.

[0013] In other words, the method for manufacturing particleboard according to this embodiment includes a compression step, a fragmentation step, a forming step, and a hot-pressing step.

[0014] In the compression process, crushed palm plants are compressed to obtain a compressed material. Here, the crushed material contains suitable chips (chips with a length of 5.0 mm to 100.0 mm and an outer diameter of 1.0 mm to 10.0 mm). The content of suitable chips is 70% by mass or more of the total mass of the crushed material.

[0015] Thus, instead of crushing palm plants, which have low bulk density and poor storage properties, and proceeding directly to the forming process, by primarily using crushed material of a size suitable for particleboard manufacturing and compressing it, the bulk density of the resulting particleboard can be increased, and the storage properties of the compressed material can also be improved. Storage properties include, for example, mold resistance. Furthermore, because it is a compressed material, its transportability can also be improved.

[0016] The three steps following the compression process—the fragmentation process, the forming process, and the hot-pressing process—are the same as those included in conventional particleboard manufacturing methods. Even after these processes, a large amount of suitable chips tend to remain in the particleboard.

[0017] Therefore, the strength of the particleboard can be improved.

[0018] 2.Details (1) Particleboard The particleboard according to this embodiment is a plate-like material formed using palm plants as raw materials. Particleboard includes single-layer particleboard, three-layer particleboard, and multi-layer particleboard.

[0019] Single-layer particleboard is a particleboard consisting of a single layer containing small pieces (particles) of roughly the same size.

[0020] Furthermore, a three-layer particleboard is a particleboard consisting of three layers (one core layer and two surface layers). That is, in a three-layer particleboard, the surface layers are arranged on both sides of the core layer in the thickness direction. Here, the particles contained in the core layer are coarse, and the particles contained in the surface layers are fine. Note that the particles contained in the core layer only need to be coarser than the particles contained in the surface layers, and the size of each particle is not particularly limited.

[0021] Furthermore, multilayer particleboard is a type of particleboard in which the size of the individual particles decreases almost continuously from the center in the thickness direction toward the surface.

[0022] Thus, compared with single-layer particle boards, three-layer particle boards and multi-layer particle boards are more likely to achieve both surface smoothness and strength. Furthermore, materials can be utilized without waste.

[0023] (2) Method for manufacturing particle board The method for manufacturing a particle board according to this embodiment includes a compression step, a fragmentation step, a forming step, and a hot pressing step. Hereinafter, these steps will be described in order.

[0024] <Compression step> In the compression step, the crushed material of a palm family plant is compressed to obtain a compressed material for manufacturing a particle board (hereinafter sometimes simply referred to as "compressed material"). Hereinafter, the crushed material of the palm family plant and the compressed material will be described in order.

[0025] ≪Crushed material of palm family plant≫ The type of palm family plant is not particularly limited. For example, it includes oil palm, saw palmetto, coconut palm, date palm, sago palm, acai, and schizophylla, etc. The available parts of palm family plants are not particularly limited. For example, they include trunk parts, leaf parts, fruit parts, inflorescence parts, and seed parts, etc.

[0026] The crushed material of palm family plant is obtained as an aggregate of chips by crushing the palm family plant with a chipper. The shape of the chips obtained by crushing the palm family plant generally has an elongated shape with a long length in the fiber direction. The chips preferably have a length of 5.0 mm or more and 100.0 mm or less, and an outer diameter of 1.0 mm or more and 10.0 mm or less. The chips corresponding to this length and outer diameter are hereinafter referred to as "suitable chips", and the chips not corresponding to the above length and outer diameter may be hereinafter referred to as "unsuitable chips". The length and outer diameter of the chips contained in the crushed material of palm family plant can be obtained by photographing a predetermined amount of the crushed material of palm family plant or observing it with a magnifying glass and measuring the length and outer diameter of the chips.

[0027] Here, having a chip length of 5.0 mm or more can suppress the reduction in the strength of the particleboard. This is also true when the outer diameter of the chip is 1.0 mm or more.

[0028] Furthermore, keeping the chip length 100.0 mm or less helps to suppress the reduction in surface smoothness of the particleboard. This is also true when the chip's outer diameter is 10.0 mm or less.

[0029] The content of preferred chips is 70% by mass or more, preferably 80% by mass or more, relative to the total amount of crushed palm plants (total amount of preferred and unsuitable chips). A preferred chip content of 70% by mass or more not only suppresses a decrease in the strength of the particleboard but also makes it easy to manufacture particleboard of more stable quality. The upper limit of the preferred chip content is not particularly limited, but for example, it is 100% by mass or less.

[0030] Here, the parenchymal cell tissue of palm plants can be a factor in variations in the quality of particleboard. Therefore, it is preferable that the crushed palm plant material is obtained by crushing the palm plant and then classifying it to reduce the amount of parenchymal cell tissue. That is, the crushed palm plant material before classification contains crushed material mainly composed of parenchymal cell tissue and crushed material mainly composed of vascular tissue, but it is preferable to reduce the amount of crushed material mainly composed of relatively small parenchymal cell tissue by classification. In this way, the amount of crushed material mainly composed of parenchymal cell tissue is reduced in the crushed material after classification compared to the crushed material before classification. As a result, the proportion of vascular tissue contained in the compressed material increases, and particleboard can be manufactured stably. Furthermore, parenchymal cell tissue contains a lot of sugar and can cause mold growth, but by reducing the proportion of parenchymal cell tissue contained in the compressed material, mold growth can be suppressed and the storage life of the compressed material can be improved. Parenchymal cell tissue is tissue composed of parenchymal cells. Parenchyma tissue includes anabolic tissue, secretory tissue, and storage tissue, and has physiological functions such as synthesis, degradation, and storage.

[0031] There are no particular limitations on the method for reducing unsuitable chips (chips mainly composed of parenchyma tissue, chips mainly composed of short vascular bundle tissue, and chips that are large in size) through classification, but one example is to use two sieves with different mesh sizes. That is, pulverized material that passes through the sieve with a large mesh size but not through the sieve with a small mesh size is more likely to have unsuitable chips removed. Here, sieves with a large mesh size include sieves of 2.16 mesh (mesh opening 9.5 mm) to 3.5 mesh (mesh opening 5.6 mm). On the other hand, sieves with a small mesh size include sieves of 6.5 mesh (mesh opening 2.8 mm) to 18 mesh (mesh opening 850 μm). Alternatively, parenchyma tissue may be selectively separated by passing the material through a particularly small sieve of about 200 mesh (mesh opening 75 μm), and then unsuitable chips may be reduced using the two sieves with different mesh sizes mentioned above.

[0032] It is preferable to dry the crushed palm plant material. The moisture content of the crushed palm plant material is preferably 25% by mass or less, more preferably 20% by mass or less. A moisture content of 25% by mass or less improves the shape retention of the compressed material. It also prevents the decay of the woody fibers contained in the compressed material, improving its storability. The moisture content of the crushed palm plant material can be determined by the total drying method.

[0033] Thus, in this embodiment, palm trees can be used as plants for particleboard manufacturing, thereby enabling the effective utilization of resources.

[0034] Compressed material The compressed material for manufacturing particleboard according to this embodiment is a compressed material obtained by compressing crushed palm plants. The shape of the compressed material is not particularly limited, but examples include pellets, briquettes, and blocks.

[0035] The size of the pelletized compressed material is not particularly limited, but is generally between 10 mm and 25 mm in outer diameter and between 30 mm and 100 mm in length. The pelletized compressed material can be obtained, for example, using a known pelletizer. Known pelletizers are not particularly limited, but include, for example, flat-die type molding machines and ring-die type molding machines. Such pelletizers have the advantage of excellent productivity of compressed material.

[0036] The size of the briquette-shaped compressed material is not particularly limited, but is typically 30 mm to 150 mm in outer diameter and 50 mm to 200 mm in length. The briquette-shaped compressed material can be obtained, for example, using a known briquette maker. Known briquettes are not particularly limited, but examples include a push-type molding machine. A push-type molding machine comprises a cylindrical mold that extends in the front-rear direction, has an inlet at the rear and an outlet at the front, and a piston positioned at the rear of the mold that reciprocates in the front-rear direction inside the mold. When using this push-type molding machine, crushed material is fed into the mold from the inlet, and the material is compressed by moving the piston forward. Next, the piston is retracted, and the next batch of crushed material is fed into the mold from the inlet, and the material is compressed by moving the piston forward. This further compresses the previously compressed material and moves it forward towards the outlet. By repeating this process, briquette-shaped compressed material is obtained sequentially from the outlet at the front of the mold. Such briquetters have the advantage that the wood fibers in the crushed material are less likely to break during feeding and compression, which can further increase the strength of the resulting particleboard.

[0037] The size of the compressed block is not particularly limited, but is generally 30 mm to 300 mm in length, 30 mm to 300 mm in width, and 30 mm to 300 mm in height. The compressed block can be obtained, for example, using a known volume reduction machine. Known volume reduction machines are not particularly limited, but examples include a single-shaft volume reduction machine that can compress the crushed material fed into the compression chamber from one direction, and a triple-shaft volume reduction machine that can compress the crushed material fed into the compression chamber from three directions. Similar to a bricketer, such volume reduction machines have the advantage that the wood fibers in the crushed material are less likely to break during feeding and compression, and the strength of the resulting particleboard can be further increased.

[0038] The specific gravity of the compressed material is preferably 0.30 to 1.60, more preferably 0.35 to 1.50, and particularly preferably 0.40 to 1.50. This improves the mechanical durability of the compressed material, making it less likely to crumble or break during transport. If the specific gravity of the compressed material is greater than 1.60, the woody fibers constituting the crushed palm plant material may be compressed and damaged, which can easily reduce the strength characteristics of the resulting particleboard. If the specific gravity of the compressed material is less than 0.30, it becomes bulky, and if there is a limit to the volume of compressed material that can be transported at one time, the number of transports required to reach the required mass of compressed material will increase.

[0039] The moisture content of the compressed material is preferably 25% by mass or less, more preferably 20% by mass or less. A moisture content of 25% by mass or less improves the shape retention of the compressed material. Furthermore, it inhibits the decay of the wood fibers contained in the compressed material, improving its storability. The moisture content of the compressed material can be determined by the total drying method.

[0040] When compressing the pulverized material, adhesives are not used; the material is integrated solely by compressive force. However, adhesives may be used if they do not interfere with the cutting of the compressed material during the fragmentation process. Alternatively, heated pulverized material may be compressed. In this case, there is the advantage that a compressed material with the desired specific gravity can be obtained even with a lower compressive force than that used when the material is not heated. Furthermore, functional materials such as antibacterial agents, fragrances, and colorants may be mixed into the pulverized material and integrated. In this case, it is preferable to impart these functions to the resulting particleboard.

[0041] <Small pieces process> The fragmentation process is a process of breaking down compressed material into smaller pieces. In other words, in the fragmentation process, small pieces (particles) are obtained by cutting the compressed material. Specifically, small pieces can be obtained from compressed material using known flakers. Here, the flaker is not particularly limited, but examples include ring flakers, drum flakers, and disc flakers.

[0042] Preferably, the obtained pieces are dried. Specifically, the pieces can be dried using a known dryer. The drying temperature is not particularly limited, but for example, it is between 100°C and 230°C. The drying time is also not particularly limited.

[0043] Here, the small pieces may be classified to obtain coarse pieces and fine pieces. Classification includes screen sorting using sieves and wind classification (separating using wind power based on differences in specific gravity). By obtaining coarse pieces and fine pieces in this way, a three-layer particleboard can be manufactured.

[0044] <Forming Process> In the forming process, a mat is obtained by adding adhesive to small pieces and forming them. Forming is preferably carried out by a dry method. In dry forming, a known gravity-type former or suction-type former can be used. In addition to the adhesive, a water-repellent agent may also be added.

[0045] The adhesive used here is not particularly limited, but examples include diphenylmethane diisocyanate (MDI), urea resin, urea-melamine cocondensation resin, and phenolic resin.

[0046] The amount of adhesive mixed with respect to the total mass of the small pieces and adhesive is not particularly limited, but for example, it is between 1% by mass and 10% by mass.

[0047] In the manufacturing of a three-layer particleboard, a three-layer mat is obtained during the forming process. The three-layer mat consists of three layers (one core layer and two surface layers). That is, in the three-layer mat, the surface layers are located on both sides of the core layer in the thickness direction. The core layer contains coarse fragments and adhesive, while the surface layers contain fine fragments and adhesive. The fragments used in the mat may consist only of fragments obtained by cutting compressed material, or fragments obtained by cutting tropical hardwoods or softwoods, which are used in the conventional manufacture of particleboard, may also be used.

[0048] <Heat pressure process> In the hot-pressing process, the mat is heated and compressed. A known hot press can be used in the hot-pressing process. A distance bar (thickness gauge) may be installed between the hot plates of the hot press. The distance bar can be used to ensure a consistent thickness for the particleboard.

[0049] The heating temperature is not particularly limited, but for example, it is between 140°C and 230°C. The pressure applied during crimping is not particularly limited, but for example, it is between 0.5 MPa and 10 MPa. The heat pressing time is not particularly limited, but for example, it is between 10 seconds and 3 minutes.

[0050] As described above, a particle board according to this embodiment is obtained. The thickness of the particle board is not particularly limited, but for example, it is 1 mm or more and 20 mm or less.

[0051] <Other> The method for manufacturing particleboard may further include a cold-pressing step. The cold-pressing step is a step in which the mat is compressed without heating after the forming step and before the hot-pressing step. The cold-pressing step is particularly effective in the manufacture of three-layer particleboard and multi-layer particleboard. This allows for temporary bonding between layers.

[0052] The manufacturing method for particleboard may further include a humidity control step. In the humidity control step, the particleboard after the hot-pressing step is left in the atmosphere for a certain period of time, or is processed in a humidity control device. Since the moisture content of the particleboard immediately after the hot-pressing step is very low, it is preferable to increase the humidity until it approaches the moisture content that is in equilibrium with the usage conditions.

[0053] Furthermore, the equipment used for these fragmentation, forming, and hot-pressing processes may be the same as that used in the conventional manufacturing of particleboard. Thus, the particleboard according to this embodiment can be produced using conventional particleboard manufacturing equipment. Therefore, the efficiency of equipment use can be increased. Consequently, even when using palm plants, which are waste materials with poor storage properties and low bulk density after drying, as raw materials, particleboard can be obtained with excellent productivity.

[0054] <Effects and Effects> As described above, the method for manufacturing particleboard according to this embodiment includes a compression step, a fragmentation step, a forming step, and a hot-pressing step.

[0055] In the compression process, crushed palm plants are compressed to obtain a compressed material. Here, the crushed material contains suitable chips (chips with a length of 5.0 mm to 100.0 mm and an outer diameter of 1.0 mm to 10.0 mm). The content of suitable chips is 70% by mass or more of the total mass of the crushed material.

[0056] Thus, instead of crushing palm plants, which have low bulk density and poor storage properties, and proceeding directly to the forming process, by primarily using crushed material of a size suitable for particleboard manufacturing and compressing it, the bulk density of the resulting particleboard can be increased, and the storage properties of the compressed material can also be improved. Furthermore, because it is a compressed material, its transportability can also be improved.

[0057] In the fragmentation process following the compression process, small pieces are obtained by cutting the compressed material. In the forming process following the fragmentation process, a mat is obtained by adding adhesive to the small pieces and forming them. In the hot-pressing process following the forming process, the mat is heated and compressed. This results in particleboard.

[0058] The length of the suitable chips may be slightly shortened through the fragmentation, forming, and hot-pressing processes. However, since a large number of suitable chips remain in the compressed material used for particleboard manufacturing, these suitable chips will still be included in the particleboard even after these processes.

[0059] Therefore, the strength of the particleboard can be improved.

[0060] 3. Appearance As is clear from the above embodiments, this disclosure includes the following aspects.

[0061] The first embodiment is a method for manufacturing particleboard, comprising a compression step, a fragmentation step, a forming step, and a hot-pressing step. In the compression step, crushed palm plants are compressed to obtain a compressed material. In the fragmentation step, small pieces are obtained by cutting the compressed material. In the forming step, an adhesive is added to the small pieces and formed to obtain a mat. In the hot-pressing step, the mat is heated and compressed. The crushed material contains chips with a length of 5.0 mm or more and 100.0 mm or less, and an outer diameter of 1.0 mm or more and 10.0 mm or less. The content of the chips is 70% by mass or more of the total mass of the crushed material.

[0062] According to this embodiment, when palm plants are used as raw materials, high-strength particleboard can be manufactured.

[0063] A second embodiment is a method for manufacturing particleboard based on the first embodiment. In the second embodiment, the specific gravity of the compressed material is 0.35 or more and 1.50 or less. The water content of the compressed material is 25% by mass or less.

[0064] According to this embodiment, the mechanical durability of the compressed material is improved. Furthermore, the storability of the compressed material is improved.

[0065] A third aspect is a method for manufacturing particleboard based on the first or second aspect. In the third aspect, the pulverized material is obtained by pulverizing the palm plant and then classifying it to reduce the amount of parenchyma tissue.

[0066] According to this embodiment, parenchyma cell tissue is less likely to be included in the compressed material, and particle board can be manufactured stably.

[0067] The fourth embodiment is a compressed material for manufacturing particleboard, which is a compressed material obtained by compressing pulverized palm plants. The pulverized material contains chips with a length of 5.0 mm or more and a length of 100.0 mm or less and an outer diameter of 1.0 mm or more and a length of 10.0 mm or less. The content of the chips is 70% by mass or more of the total mass of the pulverized material.

[0068] According to this embodiment, when palm plants are used as raw materials, high-strength particleboard can be manufactured.

[0069] The fifth embodiment is a compressed material for manufacturing particleboard based on the fourth embodiment. In the fifth embodiment, the specific gravity of the compressed material is 0.35 or more and 1.50 or less. The water content of the compressed material is 25% by mass or less.

[0070] According to this embodiment, the mechanical durability of the compressed material is improved. Furthermore, the storability of the compressed material is improved. [Examples]

[0071] The present disclosure will be described in detail below with reference to examples. However, the present disclosure is not limited to the following examples.

[0072] 1. Sample As shown in Table 1 below, for Examples 1 to 7 and Comparative Example 1, compressed material for particleboard production was obtained, and then particleboard was manufactured using this compressed material. For Comparative Example 2, particleboard was manufactured without obtaining compressed material. In Table 1, "Average chip length" is the average length of the chips contained in the crushed palm plant material (crushed material after classification). Also, in Table 1, "Average chip diameter" is the average outer diameter of the chips contained in the crushed palm plant material (crushed material after classification).

[0073] Examples 1-7 and Comparative Examples 1 and 2 will be described in detail below.

[0074] (1) Example 1 As a raw material for particleboard (from the palm family), oil palm trunks (OPT) were used and fed into a chipper to obtain pulverized material between 10 mm and 50 mm in size. After removing foreign matter from the pulverized material using a foreign matter removal machine, the material was dried to a predetermined moisture content using a jet dryer to obtain dried pulverized material.

[0075] Next, the dried pulverized material was subjected to a 7.5-mesh (2.36 mm opening) sieve and a 16-mesh (1.00 mm opening) sieve. Then, from the dried pulverized material that had been pre-sieved through a 200-mesh (75 μm opening) sieve to reduce the amount of parenchyma tissue, pulverized material that passed through the 7.5-mesh sieve but not the 16-mesh sieve was obtained. In this way, the pulverized material obtained by classification had its parenchyma tissue reduced. The average chip length, average chip diameter, and preferred chip content of the classified pulverized material are shown in Table 1.

[0076] The average chip length and average chip diameter were obtained by measuring the length and outer diameter of each chip in a predetermined amount of crushed material using a magnifying glass and calculating the arithmetic mean. The preferred chip content was obtained by measuring the length and outer diameter of the chips in a predetermined amount of crushed material using a magnifying glass, classifying them based on whether they fall within the range of 5.0 mm to 100.0 mm in length and 1.0 mm to 10.0 mm in outer diameter, and calculating the ratio of mass between chips within this range (preferred chips) and chips not within this range (unpreferred chips).

[0077] Next, a briquette-shaped compressed material was obtained from the above-mentioned crushed material using a briquette press. The specific gravity, moisture content, and size of this compressed material are shown in Table 1.

[0078] Next, the compressed material was placed in a knife ring flaker and dried in a 200°C jet dryer to obtain small pieces (particles). Diphenylmethane diisocyanate (MDI) was added to these particles as an adhesive and formed, and the resulting mat was compressed while being heated at 180°C for 6 minutes to obtain a mat with a thickness of 12 mm and a density of 750 kg / m². 3 A particleboard was obtained. The amount of adhesive added was 10% by mass.

[0079] (2) Example 2 The classified pulverized material was obtained in the same manner as in Example 1, except that the mesh sizes of the two sieves were changed. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0080] Next, a tri-shaft volume reducer was used to obtain a block-shaped compressed material from the above-mentioned pulverized material. The specific gravity, moisture content, and size of this compressed material are shown in Table 1.

[0081] Then, using the compressed material described above, a particleboard was manufactured in the same manner as in Example 1. The thickness and density of the particleboard in Example 2 are the same as those of the particleboard in Example 1.

[0082] (3) Example 3 The classified pulverized material was obtained in the same manner as in Example 1, except that the mesh sizes of the two sieves were changed. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0083] Next, a flat-die pelletizer was used to obtain compressed pellets from the above-mentioned crushed material. The specific gravity, moisture content, and size of these compressed pellets are shown in Table 1.

[0084] Then, using the compressed material described above, a particle board was manufactured in the same manner as in Example 1. The thickness and density of the particle board in Example 3 are the same as those of the particle board in Example 1.

[0085] (4) Example 4 The pulverized material after classification was obtained in the same manner as in Example 1. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0086] Next, using a briquette press, a briquette-shaped compressed product was obtained from the above-mentioned pulverized material under the same conditions as in Example 1. The specific gravity, moisture content, and size of this compressed product are shown in Table 1.

[0087] Then, particleboard was manufactured using the compressed material described above in the same manner as in Example 1. The thickness and density of the particleboard in Example 4 are the same as those of the particleboard in Example 1.

[0088] (5) Example 5 Except for using coconut palm trunks as the raw material (a type of palm plant) for the particleboard and changing the mesh sizes of the two sieves, the classified pulverized material was obtained in the same manner as in Example 1. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0089] Next, a compressed material was obtained in the same manner as in Example 1. The specific gravity, water content, and size of this compressed material are shown in Table 1.

[0090] Then, using the compressed material described above, a particle board was manufactured in the same manner as in Example 1. The thickness and density of the particle board in Example 5 are the same as those of the particle board in Example 1.

[0091] (6) Example 6 The classified pulverized material was obtained in the same manner as in Example 1, except that the mesh sizes of the two sieves were changed. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0092] Next, a tri-shaft volume reducer was used to obtain a block-shaped compressed material from the above-mentioned pulverized material. The specific gravity, moisture content, and size of this compressed material are shown in Table 1.

[0093] Then, particleboard was manufactured using the compressed material described above in the same manner as in Example 1. The thickness and density of the particleboard in Example 6 are the same as those of the particleboard in Example 1.

[0094] (7) Example 7 The classified pulverized material was obtained in the same manner as in Example 1, except that the mesh sizes of the two sieves were changed. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0095] Next, a tri-shaft volume reducer was used to obtain a block-shaped compressed material from the above-mentioned pulverized material. The specific gravity, moisture content, and size of this compressed material are shown in Table 1.

[0096] Then, using the compressed material described above, a particleboard was manufactured in the same manner as in Example 1. The thickness and density of the particleboard in Example 7 are the same as those of the particleboard in Example 1.

[0097] (8) Example 8 The classified pulverized material was obtained in the same manner as in Example 1, except that the mesh sizes of the two sieves were changed. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0098] Next, a flat-die pelletizer was used to obtain compressed pellets from the above-mentioned crushed material. The specific gravity, moisture content, and size of these compressed pellets are shown in Table 1.

[0099] Then, particle board was manufactured using the compressed material described above in the same manner as in Example 1. The thickness and density of the particle board in Example 8 are the same as those of the particle board in Example 1.

[0100] (9) Example 9 The pulverized material after classification was obtained in the same manner as in Example 1. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0101] Next, using a briquette press, a briquette-shaped compressed product was obtained from the above-mentioned pulverized material under the same conditions as in Example 1. The specific gravity, moisture content, and size of this compressed product are shown in Table 1.

[0102] Then, particleboard was manufactured using the compressed material described above in the same manner as in Example 1. The thickness and density of the particleboard in Example 9 are the same as those of the particleboard in Example 1.

[0103] (10) Comparative Example 1 The classified pulverized material was obtained in the same manner as in Example 1, except that the mesh sizes of the two sieves were changed. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0104] Next, a flat-die pelletizer was used to obtain compressed pellets from the above-mentioned crushed material. The specific gravity, moisture content, and size of these compressed pellets are shown in Table 1.

[0105] Then, particleboard was manufactured using the compressed material described above in the same manner as in Example 1. The thickness and density of the particleboard of Comparative Example 1 are the same as those of the particleboard of Example 1.

[0106] (11) Comparative Example 2 Except for using cedar as the raw material for particleboard and changing the mesh sizes of the two sieves, the classified pulverized material was obtained in the same manner as in Example 1. The average chip length, average chip diameter, and preferred chip content of this pulverized material are shown in Table 1.

[0107] Then, without obtaining a compressed product from the above-mentioned pulverized material, the dried pulverized material was used as small pieces (particles) to manufacture a particle board in the same manner as in Example 1. The thickness and density of the particle board of Comparative Example 2 are the same as those of the particle board of Example 1.

[0108] 2. Exam (1) Mechanical durability of compressed material In accordance with the "Wood Pellet Quality Standards" of the Japan Wood Pellet Association, the mechanical durability of compressed materials was evaluated using a durability tester equipped with a rotating box. The mechanical durability DU was calculated using the following formula and classified according to the evaluation criteria below.

[0109] DU = (m1 / m0) × 100 (%) DU: Mechanical durability (%) m0: Mass of the compressed material before rotation (g) m1: Mass (g) of the compressed material remaining in the sieve after rotational processing. <Evaluation Criteria> A: 97.5% or more B: 96.5% or more and less than 97.5% C: Less than 96.5%.

[0110] Furthermore, evaluations A and B are deemed to be without practical problems.

[0111] (2) Storage properties of compressed materials The mold resistance of compressed materials was evaluated in accordance with "JIS Z 2911 Mold Resistance Test Method". The state of mold growth was classified according to the following evaluation criteria, and the storability was assessed.

[0112] <Evaluation Criteria> A: No mold growth is observed even after 14 days or more. B: Mold growth is observed between 10 and 14 days. C: Mold growth can be observed in less than 10 days.

[0113] Furthermore, evaluations A and B are deemed to be without practical problems.

[0114] (3) Strength of particle board The bending strength of particleboard was measured in accordance with "JIS A 5908 Particleboard". The measured values ​​were classified according to the following evaluation criteria, and the strength was evaluated.

[0115] <Evaluation Criteria> A: Bending strength of 18 MPa or more B: Bending strength between 15 MPa and less than 18 MPa C: Bending strength is less than 15 MPa.

[0116] Furthermore, evaluations A and B are deemed to be without practical problems.

[0117] [Table 1]

[0118] From a comparison of Examples 1-9 and Comparative Example 1, it was confirmed that when palm plants are used as raw materials, the strength of the particleboard is improved if the content of suitable chips in the pulverized material is 70% by mass or more.

[0119] Since the particleboards in Examples 1-9 and Comparative Example 2 had similar strengths, it was confirmed that palm trees, which were previously considered more difficult to handle as building materials compared to cedar, can also be effectively utilized.

[0120] A comparison of Examples 1-5, 8-9 with Examples 6 and 7 confirmed that the mechanical durability of the compressed material improves when its specific gravity is 0.35 or higher.

[0121] A comparison of Examples 1-7 and 9 with Example 8 confirmed that the strength of the particleboard improves when the specific gravity of the compressed material is 1.50 or less.

[0122] A comparison of Examples 1-8 and Example 9 confirmed that the storability of the compressed material improves when its water content is 25% by mass or less.

Claims

1. A compression process to obtain a compressed material by compressing crushed palm plants, A fragmentation step to obtain small pieces by cutting the compressed material, A forming step to obtain a mat by adding adhesive to the aforementioned small pieces and forming them, The process includes a hot-pressing step in which the mat is heated and compressed, The aforementioned pulverized material contains chips with a length of 5.0 mm or more and 100.0 mm or less, and an outer diameter of 1.0 mm or more and 10.0 mm or less. The content of the chips is 70% by mass or more of the total mass of the pulverized material. The aforementioned pulverized material is obtained by pulverizing the palm plant and then classifying it to reduce the amount of parenchyma tissue. A method for manufacturing particleboard.

2. The specific gravity of the compressed material is 0.35 or more and 1.50 or less, and the water content of the compressed material is 25% by mass or less. A method for manufacturing particle board according to claim 1.

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