Method for binding plant-derived fragments, composition for binding plant-derived fragments, molded body of plant-derived fragments, and method for manufacturing molded body of plant-derived fragments

Abstract

This invention provides a low-cost and simple method for binding plant-derived fragments, a highly safe binding composition, and a molded plant-derived fragment body and a method for manufacturing the molded plant-derived fragment body, using plant-derived materials as examples of waste products generated as a result of plant resource production. [Solution] The method for binding plant-derived fragments is characterized by using mushroom fruiting body-derived fibers as a binding component to bind the plant-derived fragments. The composition for binding plant-derived fragments is characterized by containing mushroom fruiting body-derived fibers as a binding component. The molded plant-derived fragment is characterized by containing mushroom fruiting body-derived fibers and plant-derived fragments. The method for producing the molded plant-derived fragment is characterized by mixing mushroom fruiting body-derived fibers, which are the binding component, with plant-derived fragments, which are the component to be bound (S01), and drying them (S02).

Description

Technical Field

[0001] The present invention relates to a method for binding plant-derived fragments, a composition for binding plant-derived fragments, a plant-derived fragment molded body, and a method for producing a plant-derived fragment molded body.

Background Art

[0002] Plant resources play a role in maintaining human life and health by serving as a source of energy or nutrition as food, or by being involved in the growth of other resource organisms as feed, green manure, culture media, etc. In addition, plant resources are used as fibers for clothing or as building materials for houses. Thus, plant resources are important biological resources that support human food, clothing, and shelter.

[0003] On the other hand, the production of plant resources also generates unwanted plant-derived substances. Specific examples include non-harvested parts of agricultural crops, waste materials generated during the manufacturing process of clothing, waste materials generated during the manufacturing process of lumber, used building materials generated by the demolition of wooden houses, and waste culture media for mushrooms.

[0004] The effective utilization of plant-derived substances exemplified in such unwanted substances generated as a result of plant resource production has become an issue. And one of the solutions is to use them as plant-derived fragment molded bodies obtained by fragmenting and binding these plant-derived substances (Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-089988).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Conventionally, particleboard is known that is formed by binding wood chips together with a binder derived from fossil resources. However, binders derived from fossil resources often contain formaldehyde, which may have adverse effects on human health and the environment depending on the concentration. In contrast, Patent Document 1 (Japanese Patent Application Publication No. 2020-089988) describes a biomass molded body formed by mixing a polycarboxylic acid and an ammonium salt with pulverized plant material or veneer containing sugars, pressing it, and then heating and pressurizing it. The invention described in Patent Document 1 hardens by reacting the sugars in the plant with a polycarboxylic acid, and catalyzing this reaction with an ammonium salt. While this eliminates the need for binders derived from fossil resources, it has drawbacks such as being complicated and costly due to the use of multiple chemical substances. [Means for solving the problem]

[0007] Against this backdrop, the present invention aims to provide a low-cost and simple method for binding plant-derived fragments, a highly safe binding composition, and a molded plant-derived fragment and a method for manufacturing the molded plant-derived fragment, using plant-derived materials as examples of waste products generated as a result of plant resource production.

[0008] The present invention solves the above problem by a solution described below as one embodiment.

[0009] In other words, one embodiment of the present invention is a method for binding plant-derived fragments, characterized by using mushroom fruiting body-derived fibers as a binding component to bind plant-derived fragments.

[0010] Furthermore, one embodiment of the present invention is a plant-derived fragment binding composition characterized by containing mushroom fruiting body-derived fibers as a binding component.

[0011] Furthermore, one embodiment of the present invention is a plant-derived fragment molded body characterized by containing mushroom fruiting body-derived fibers and plant-derived fragments.

[0012] Furthermore, one embodiment of the present invention is a method for producing a molded plant-derived fragment, characterized by mixing mushroom fruiting body-derived fibers, which are binding components, with plant-derived fragments, which are components to be bound, shaping the mixture into a predetermined form, and then drying it. As an example, mushroom fruiting bodies, plant-derived materials, and / or water may be added as needed to spent culture medium after mushroom cultivation, the mixture is stirred and pulverized, shaped into a predetermined form, and then dried.

[0013] This invention is based on the novel discovery that plant fibers can be bound together using mushroom fruiting body-derived fibers as a binding component. According to this invention, a molded plant-derived fragment can be formed by binding the fibers of each plant-derived fragment together with mushroom fruiting body-derived fibers. Mushroom fruiting body-derived fibers are natural materials with high safety, can utilize waste materials generated during the production, processing, distribution, and sales processes of mushrooms, and can be obtained easily and at low cost simply by crushing the fruiting bodies. The method of binding the plant-derived fragments is also an extremely simple process, and the molded plant-derived fragment can be manufactured at low cost with simple equipment. Because this molded plant-derived fragment is composed only of natural materials, it is highly safe, can maintain its shape, has a certain strength, and its porosity can be changed by adjusting the mixing ratio of mushroom fruiting body-derived fibers and plant-derived fragments. By taking advantage of these properties, this molded plant-derived fragment has various industrial applications. [Effects of the Invention]

[0014] According to the present invention, it is possible to manufacture a molded body of plant-derived fragments at low cost and in a simple manner by binding plant-derived fragments at a high level of safety using a plant-derived fragment binding composition, using plant-derived materials, which are examples of waste products generated as a result of plant resource production, as the raw material. [Brief explanation of the drawing]

[0015] [Figure 1] Figures 1A, 1B, 1C, 1D, and 1E are photographs of examples of plant-derived fragments. [Figure 2]FIG. 2 is a flowchart showing an example of a method for producing a plant-derived fragment molded body according to the present embodiment. [Figure 3] FIGS. 3A and 3B are external appearance photographs of the plant-derived fragment molded body in Test 1. [Figure 4] FIGS. 4A, 4B, 4C, 4D, 4E, and 4F are magnified photographs of the surface of the plant-derived fragment molded body in Test 1. [Figure 5] FIG. 5 is a graph showing the maximum bending stress of the plant-derived fragment molded body in Test 2. [Figure 6] FIG. 6 is a magnified photograph of the mushroom fruiting body-derived fiber (mushroom fruiting body pulverized product) in Test 3. [Figure 7] FIGS. 7A and 7B are magnified photographs photographs of the surface of the plant-derived fragment molded body in Test 3. [Figure 8] FIG. 8 is a graph showing the maximum bending stress and bending Young's modulus of the plant-derived fragment molded body in Test 3. [Figure 9] FIG. 9 is a graph showing the porosity of the plant-derived fragment molded body in Test 3.

MODE FOR CARRYING OUT THE INVENTION

[0016] [Method for Binding Plant-Derived Fragments, Composition for Binding Plant-Derived Fragments] The present invention is based on the newly found fact that plant fibers can be bound using mushroom fruiting body-derived fibers as a binding component. One aspect of the present invention is a highly specific creative technical idea as a substance and method for binding plant-derived fragments by binding the fibers of each plant-derived fragment to each other.

[0017] That is, one aspect of the mode for carrying out the present invention is a method for binding plant-derived fragments, characterized by binding plant-derived fragments using mushroom fruiting body-derived fibers as a binding component. Also, one aspect of the mode for carrying out the present invention is a composition for binding plant-derived fragments, characterized by containing mushroom fruiting body-derived fibers as a binding component.

[0018] (Fibers derived from mushroom fruiting bodies) The binding component, mushroom fruiting body-derived fiber, is a fiber obtained from the fruiting bodies of mushrooms. Here, "mushroom" refers to a group of organisms belonging to the fungi, where hyphae gather to form fruiting bodies. Examples of mushrooms include enoki, maitake, buna-shimeji, oyster mushroom, sparassis crispa, king oyster mushroom, shiitake, nameko, button mushroom, and reishi mushroom. Since any type of mushroom can be a binding component, the binding component may consist of a mixture of fibers derived from multiple types of mushroom fruiting bodies.

[0019] In this context, a fruiting body is a structure formed by the aggregation of mycelium into a specific shape. The fruiting body includes not only the cap of the mushroom, but also the ring, stem, and volva, or in other words, the stalk and base. While fruiting bodies are produced as edible mushrooms, a certain amount of waste material exists in the mushroom production, processing, distribution, and sales process, such as surplus products, substandard products, defective products, unsold products, unused parts (e.g., bases), and residues from previous uses (e.g., residues after component extraction). This embodiment is beneficial because it allows for the effective utilization of such waste material. For example, if the mycelium (mycelial body) of the mushroom is the binding component, it is highly likely that cultivation will be required to secure a predetermined amount, which could lead to higher costs.

[0020] Mushroom fruiting body-derived fibers are structurally a group of fibers obtained by defibrating a mushroom fruiting body to a certain extent. This degree of defibration can be indicated by the average fiber width. This average fiber width is defined as the average value of the total fiber widths measured by acquiring an image of the target sample using an optical microscope, such as a digital microscope, or an electron microscope, such as a scanning electron microscope, from the image, and extracting 30 target fibers from the image. If necessary, when extracting target fibers, for example, methods such as visually classifying the fibers in the image into about three categories based on width and extracting approximately the same number from each category, or performing measurements on multiple images and taking the average, are used to ensure that the fiber width is not biased depending on the measurement method.

[0021] The degree of defibration of mushroom fruiting body-derived fibers is not limited, but for example, if the average fiber width is 500 μm or less, it can function sufficiently as a binding component. While these mushroom fruiting body-derived fibers mainly consist of fibers with a fiber width of 500 μm or less and have high binding performance, it is also acceptable for fibers with a fiber width exceeding 500 μm (for example, fibers with a fiber width of several millimeters that are visible to the naked eye) to be mixed in. As will be described later, such relatively large fibers also have the effect of binding plant-derived fragments. Furthermore, such relatively large fibers may also play a role as part of the constituent material in the plant-derived fragment molded body obtained by binding.

[0022] As a fiber derived from mushroom fruiting bodies, finely ground mushroom fruiting bodies are preferred. The method of finely grinding the fruiting bodies is not limited, but for example, water can be added according to the degree of dryness of the fruiting bodies and then ground in a grinding device. It is not always necessary to add water to fruiting bodies that contain sufficient moisture. Since mushroom fruiting bodies have a relatively high moisture content, wet grinding is generally preferred. On the other hand, dried mushroom fruiting bodies can also be wet-ground by adding water, but dry grinding may also be performed using a dry grinding device, for example.

[0023] The resulting pulverized mushroom fruiting bodies, as shown in Figure 6 of the later example, are mushroom fruiting body-derived fibers with an average fiber width of approximately 5 to 500 μm, and can function sufficiently as a binding component. Furthermore, passing the pulverized fruiting bodies through a sieve makes it easier to adjust the average fiber width. Figure 6 shows the results of adding an appropriate amount of water to enoki mushroom (Flammulina velutipes) fruiting bodies, pulverizing them in a household blender, and then passing them through a sieve with a mesh size of 1 mm.

[0024] On the other hand, mushroom fruiting body-derived fibers with an average fiber width of, for example, several hundred nanometers or less, obtained by further defibration of the fruiting body using chemicals, enzymes, or bacteria, may also be used. However, such defibration methods are generally time-consuming and tend to be costly. Furthermore, considering that sufficient binding effect is already achieved with an average fiber width of 500 μm or less or 5 to 500 μm, it is more preferable for mushroom fruiting body-derived fibers to have an average fiber width of, for example, 500 μm or less or 5 to 500 μm. As mentioned above, a suitable mushroom fruiting body-derived fiber is a pulverized mushroom fruiting body obtained by finely pulverizing the mushroom fruiting body.

[0025] (Plant-derived fragments) The plant-derived fragments that are bound are fragments obtained from plant-derived materials. Here, "plant-derived materials" refers to plant bodies or processed products thereof, without any limitations, including herbaceous plants and woody conifers and broad-leaved trees. Plant-derived materials exist in a certain amount as waste generated as a result of plant resource production, such as unharvested parts of crops, scraps generated in the clothing manufacturing process, scraps generated in the timber manufacturing process, used building materials generated from the demolition of wooden houses, and spent mushroom growing media. This embodiment is beneficial in that it allows for the effective utilization of such waste materials.

[0026] Plant-derived fragments are structurally groups of fragments of plant-derived material that have been fragmented to a certain extent. However, plant-derived material that is originally fragmented can itself become plant-derived fragments that are bound. The size of the plant-derived fragments used as binding components is not limited; materials ranging from pulverized material that retains some form of plant organ or part thereof to fibrous material that has been defibrated to a certain extent or more can be bound together. For example, coarse pulverized material of several centimeters or more as shown in Figure 1D, pulverized material and fibrous material of several millimeters as shown in Figures 1A and 1C, and fibrous material of several micrometers to several millimeters as shown in Figures 1B and 1E can all be bound, and it has been confirmed that these can actually be bound. Figure 1A shows the crushed dried cone of Larix kaempferi, Figure 1B shows the fibrous material of the dried cone of Cedar deodara, Figure 1C shows the coarse fibrous material of the dried cone of Cedar deodara, Figure 1D shows the coarse crushed dried stem and leaf of Sorghum bicolor, and Figure 1E shows the fibrous material of the dried stem and leaf of Sorghum bicolor.

[0027] Thus, since any type of plant and any size of fragment can be a binding component, the binding component may consist of a mixture of multiple types of plant-derived fragments, and / or a mixture of plant-derived fragments of various sizes or levels of defibration.

[0028] According to this embodiment, plant-derived fragments can be bound together using mushroom fruiting body-derived fibers as a binding component. This allows for the formation of a plant-derived fragment molded body, as described later. Both the mycelial cell surface constituting the mushroom fruiting body-derived fibers and the plant cell surface constituting the plant-derived fragments are rich in polysaccharides (cellulose, hemicellulose, β-glucan, chitin, etc.) that contain many hydroxyl groups (-OH). Therefore, by using mushroom fruiting body-derived fibers as a binding component, the fibers of each plant-derived fragment can be bound together by numerous hydrogen bonds via the mushroom fruiting body-derived fibers.

[0029] Figures 7A and 7B, which are examples described later, are magnified photographs of the surface of a plant-derived fragment molded body bound together by mushroom fruiting body-derived fibers as shown in Figure 6. The plant-derived fragments in the photographs are made by coarsely grinding dried sorghum (Sorghum bicolor) stems and leaves, then finely grinding them in a household blender and passing them through a sieve with a mesh size of 1 mm. As shown in Figure 7B (magnification: 200x), which has a higher magnification, relatively small-sized mushroom fruiting body-derived fibers (white dotted arrows) (e.g., fiber width of several μm or more or less) adhere to each other by cross-linking the fibers of each plant-derived fragment, thus binding the plant-derived fragments together. This can be seen as a typical binding mode due to the numerous hydrogen bonds described above. Also, as shown in Figure 7A (magnification: 50x), which has a lower magnification, relatively large-sized mushroom fruiting body-derived fibers (white solid arrows) (e.g., fiber width of several hundred μm or less or more) intertwine to cover each other's fibers, thus binding the plant-derived fragments together. While it is thought that numerous hydrogen bonds are also occurring as described above, this can be considered another form of binding. Thus, plant-derived fragments are bound together by a multilayered network where the bonds between fibers at a microscopic scale are aggregated at a macroscopic scale.

[0030] Thus, with mushroom fruiting body-derived fibers, plant-derived fragments can be firmly bound together in different ways depending on the size of the fibers. Therefore, according to this embodiment, by using mushroom fruiting body-derived fibers with a relatively wide fiber width distribution as the binding component, a novel structure of plant-derived fragments can be obtained, bound together in a specific manner.

[0031] (Plant-derived fragment binding composition) The composition of a plant-derived fragment binding composition containing mushroom fruiting body-derived fibers as a binding component is not limited in its composition, as long as it does not impair the binding performance of the binding component. For example, in addition to mushroom fruiting body-derived fibers, the plant-derived fragment binding composition may contain additive components such as excipients, hygroscopic agents, preservatives, deodorants, colorants, and solid particles that maintain, enhance, or impart predetermined properties to the plant-derived fragment binding composition and / or the molded plant-derived fragment. Furthermore, the plant-derived fragment binding composition may be in any form, such as a powder, granules, a molded product combining these, a paste-like gel, or a liquid sol. In the case of a solid molded product, it is assumed that the composition will break down in the presence of moisture while simultaneously exhibiting its binding performance.

[0032] [Plant-derived fragment molded body, method for manufacturing plant-derived fragment molded body] Another embodiment of the present invention is the creation of a highly concrete technical concept as a result obtained by binding plant-derived fragments together by binding the fibers of each plant-derived fragment together, and a method for producing the result.

[0033] In other words, one alternative embodiment for carrying out the present invention is a plant-derived fragment molded body characterized by comprising mushroom fruiting body-derived fibers and plant-derived fragments. Another alternative embodiment for carrying out the present invention is a method for producing a plant-derived fragment molded body, characterized by mixing mushroom fruiting body-derived fibers, which are binding components, with plant-derived fragments, which are components to be bound, shaping the mixture into a predetermined form, and then drying it. As an example, one can take a method in which mushroom fruiting bodies, plant-derived materials, and / or water are added as needed to spent culture medium after mushroom cultivation, the mixture is stirred and pulverized, shaped into a predetermined form, and then dried.

[0034] (Method for manufacturing plant-derived fragment molded bodies) Figure 2 is a flowchart showing an example of a method for manufacturing a plant-derived fragment molded body according to this embodiment. A plant-derived fragment molded body (hereinafter sometimes simply referred to as "molded body") can be easily manufactured by performing a mixing step S01 in which a binding component, which is a mushroom fruiting body-derived fiber, and a plant-derived fragment, which is the component to be bound, is mixed and the mixture is shaped into a predetermined form, and then a drying step S02 in which the mixture is dried.

[0035] Mixing step S01 involves, for example, mixing mushroom fruiting body-derived fibers and plant-derived fragments in a predetermined ratio, adding an appropriate amount of water and stirring, then removing some of the water from the mixture and shaping it into a predetermined form. The mixing method is not limited, but it is preferable to add an appropriate amount of water to make the binding component and the component to be bound more homogeneous. It is also preferable to add an appropriate amount of water to shape the mixture into a predetermined form in order to obtain a molded body. Since the water will be removed later, the amount added is not limited. Also, since the water will be almost completely removed in the end, the degree to which water is removed from the mixture is not limited.

[0036] Known apparatus and equipment can be used for stirring the mixture, removing moisture, and adjusting its shape. Depending on the stirring method, pulverization and defibration of the mushroom fruiting body-derived fibers and plant-derived fragments may occur, but this is generally not detrimental to the production of the molded body, so the progression of pulverization and defibration is acceptable. Also, as shown in the examples described later, depending on the moisture removal method, relatively small-sized mushroom fruiting body-derived fibers may be lost along with the moisture. Therefore, depending on the molded body to be obtained, moisture removal should be performed slowly, but as shown in the examples described later, it has been confirmed that a molded body that can maintain its shape can be obtained even with only relatively large-sized mushroom fruiting body fibers.

[0037] In the example described below (Test 1), a Büchner funnel and a suction flask were used to separate the mixture from the water, and water removal was facilitated by suction from the flask with an aspirator. In this example, the Büchner funnel was also used as a mold to shape the mixture. A similar mechanism can be used in implementation. For example, the mixture can be poured into a mold placed on a mesh, and water removal can be facilitated by suction from below as needed. Then, by removing the mold, a certain amount of water can be removed from the mixture, and the mixture can be shaped into a predetermined form.

[0038] As mentioned above, it is preferable to set the average fiber width of the mushroom fruiting body-derived fibers to 500 μm or less, or 5 to 500 μm. For such mushroom fruiting body-derived fibers, pulverized mushroom fruiting bodies are preferred. Furthermore, as mentioned above, the plant-derived fragments used may consist of a mixture of multiple types of plant-derived fragments, and / or a mixture of plant-derived fragments of various sizes or levels of defibration. In addition to the mushroom fruiting body-derived fibers and plant-derived fragments, additives such as hygroscopic agents, preservatives, deodorants, colorants, and solid particles may be mixed in, to the extent that they do not impair the binding performance of the mushroom fruiting body-derived fibers, to maintain, enhance, or impart predetermined properties to the molded body.

[0039] The mixing ratio of the crushed mushroom fruiting body material and the plant-derived fragments is not limited, but the properties of the resulting molded article can be changed depending on the mixing ratio. This mixing ratio can be indicated by the dry matter ratio (A:B) of the mushroom fruiting body-derived fibers (A) and the plant-derived fragments (B), or the mixing ratio [mass%] (=[A / (A+B)]×100) of the mushroom fruiting body-derived fibers in the said dry matter ratio (A:B) (symbol A is the dry matter amount of the mushroom fruiting body-derived fibers, and symbol B is the dry matter amount of the plant-derived fragments). As will be described in detail in the examples, in terms of the shape retention and strength of the resulting molded article, the lower limit of the mixing ratio of mushroom fruiting body-derived fibers is preferably 0.5 mass% (A:B=0.5:95.5) or more, more preferably 1 mass% (A:B=1:99) or more, and even more preferably 10 mass% (A:B=10:90) or more. Furthermore, in terms of balancing the strength of the resulting molded article with the usability of the binding components, the upper limit of the mixing ratio of mushroom fruiting body-derived fibers is preferably 90% by mass (A:B=90:10) or less, more preferably 80% by mass (A:B=80:20) or less, and even more preferably 70% by mass (A:B=70:30) or less.

[0040] Furthermore, to obtain a molded article with unique properties that combines a certain strength and a certain porosity, the mixing ratio of mushroom fruiting body-derived fibers is preferably 40 to 60% by mass (in the range of A:B=40:60 to A:B=60:40).

[0041] From the above viewpoint, the preferred range for the mixing ratio of mushroom fruiting body-derived fibers in the dry matter ratio of mushroom fruiting body-derived fibers to plant-derived fragments can be set to 0.5-90% by mass, 0.5-80% by mass, 0.5-70% by mass, 1-90% by mass, 1-80% by mass, 1-70% by mass, 10-90% by mass, 10-80% by mass, 10-70% by mass, 0.5-60% by mass, 1-60% by mass, 10-60% by mass, 40-60% by mass, etc. Alternatively, when expressed as the dry matter ratio of mushroom fruiting body-derived fibers to plant-derived fragments, it can be set to ranges such as 0.5:99.5 to 90:10, 0.5:99.5 to 80:20, 0.5:99.5 to 70:30, 1:99 to 90:10, 1:99 to 80:20, 1:99 to 70:30, 10:90 to 90:10, 10:90 to 80:20, 10:90 to 70:30, 0.5:99.5 to 60:40, 1:99 to 60:40, 10:90 to 60:40, 40:60 to 60:40, etc.

[0042] Next, in drying step S02, the mixture containing mushroom fruiting body-derived fibers and plant-derived fragments is dried to completely or to a similar extent to remove moisture from the mixture. This results in a molded body in which the plant-derived fragments are bound together and formed into a predetermined shape. The drying method of the mixture is not limited, and known apparatus and equipment can be used for drying. For example, constant temperature drying (high temperature drying), hot air drying, freeze-drying, etc., using known apparatuses can be applied. The drying conditions can be adjusted according to the size of the molded product, etc. In the examples described later, a sample with a thickness of about 1.5 cm was completely dried in appearance by maintaining a constant temperature of 120°C for 12 hours or more (Test 1). In addition, complete drying was achieved by maintaining a constant temperature until there was no change in mass (Tests 2 and 3).

[0043] One of the simplest and most efficient applications of the method for producing plant-derived fragment molded bodies described above is the use of spent culture medium after mushroom cultivation. Mushroom culture medium is generally composed of biological resources consisting of a base material such as sawdust or corn cob, and nutrients such as rice bran, wheat bran, soybean meal, or soybean hulls. After mushroom cultivation, most of the nutrients are usually decomposed and absorbed by the mushroom fungus and disappear, but most of the base material remains. In addition, even after harvesting the mushroom fruiting bodies, some parts of the fruiting bodies, such as the stem base, may remain in the spent culture medium. In other words, since spent mushroom culture medium basically contains mushroom fruiting bodies and plant-derived materials that can be used as material for plant-derived fragment molded bodies, the materials can be supplemented according to their respective content ratios, or the spent culture medium can be used as is in this embodiment. Therefore, in mixing step S01, mushroom fruiting bodies, plant-derived materials, and / or water are added to the spent culture medium after mushroom cultivation as needed, and the mixture is stirred and crushed to the necessary extent to form a predetermined shape. The stirring and grinding may be completed simultaneously in one step, or they may be completed separately as one operation primarily for stirring and the other primarily for grinding. Next, in drying step S02, the mixture is dried. This makes it possible to produce plant-derived fragment molded bodies very simply and efficiently.

[0044] (Plant-derived fragment molded material) The plant-derived fragment molded body produced in this manner is characterized by containing mushroom fruiting body-derived fibers and plant-derived fragments. This molded body can maintain its shape, possesses a certain strength, and its porosity can be changed by varying the mixing ratio of mushroom fruiting body-derived fibers and plant-derived fragments. By utilizing these properties, this molded body has various industrial applications. For example, since this molded body can be constructed without containing substances that cause sick building syndrome, such as formaldehyde, it is suitable as a highly safe building material. Also, for example, since this molded body can be constructed solely from biomass, it is suitable as a reusable packaging material. Furthermore, when a molded body manufactured with a mixing ratio of mushroom fruiting body-derived fibers of 40% by mass to possess both a certain strength and a certain porosity was plotted on a log-log chart of Ashby's Young's modulus and density, it was shown that the molded body had properties similar to those of a porous body made of a soft polymer, such as urethane foam. Therefore, this molded body has the potential to be used in applications similar to those of a porous body made of a soft polymer.

[0045] Furthermore, unless there is extreme crushing, defibration, or loss of materials during manufacturing, the constituent properties of the mushroom fruiting body-derived fibers and plant-derived fragments do not usually change significantly during manufacturing (compounding), and the mixing ratio of mushroom fruiting body-derived fibers and plant-derived fragments does not significantly change as their content ratio in the molded plant-derived fragments. Therefore, it can be said that it is preferable for the molded plant-derived fragments to have an average fiber width of 500 μm or less or an average fiber width of 5 to 500 μm. Furthermore, in the molded plant-derived fragments, it is preferable that the content of mushroom fruiting body-derived fibers in the dry matter ratio of mushroom fruiting body-derived fibers to plant-derived fragments is 0.5-90% by mass, 0.5-80% by mass, 0.5-70% by mass, 1-90% by mass, 1-80% by mass, 1-70% by mass, 10-90% by mass, 10-80% by mass, 10-70% by mass, 0.5-60% by mass, 1-60% by mass, 10-60% by mass, 40-60% by mass, etc. Alternatively, in the plant-derived fragment molded body, the dry matter ratio of mushroom fruiting body-derived fibers to plant-derived fragments is preferably in the range of 0.5:99.5 to 90:10, 0.5:99.5 to 80:20, 0.5:99.5 to 70:30, 1:99 to 90:10, 1:99 to 80:20, 1:99 to 70:30, 10:90 to 90:10, 10:90 to 80:20, 10:90 to 70:30, 0.5:99.5 to 60:40, 1:99 to 60:40, 10:90 to 60:40, 40:60 to 60:40, etc.

[0046] In the embodiments of the present invention described above, a molded body of plant-derived fragments can be formed by binding the fibers of each plant-derived fragment together with fibers derived from mushroom fruiting bodies. The fibers derived from mushroom fruiting bodies are natural materials and highly safe, and can utilize waste materials generated during the production, processing, distribution, and sales processes of mushrooms. They can be obtained easily and at low cost simply by crushing the fruiting bodies. The method for binding the plant-derived fragments is also an extremely simple process, and a molded body of plant-derived fragments can be manufactured at low cost using simple equipment. This molded body of plant-derived fragments is highly safe because it is composed only of natural materials, can maintain its shape, has a certain strength, and its porosity can be changed by adjusting the mixing ratio of the fibers derived from mushroom fruiting bodies and the plant-derived fragments. [Examples]

[0047] [Test 1] Plant-derived fragment molded bodies were manufactured. For the mushroom fruiting body-derived fibers, an appropriate amount of water was added to the fruiting bodies of the enoki mushroom (Flammulina velutipes) and ground them in a household blender. For the plant-derived fragments, ground dried cones of the larch tree (Larix kaempferi) were used. The mixing ratio of mushroom fruiting body-derived fibers to plant-derived fragments in terms of dry matter weight was set to 0% by mass (Comparative Example 1), 10% by mass (Example 1), 20% by mass (Example 2), 30% by mass (Example 3), 40% by mass (Example 4), 50% by mass (Example 5), 60% by mass (Example 6), 70% by mass (Example 7), 80% by mass (Example 8), and 90% by mass (Example 9), respectively. Mushroom fruiting body-derived fibers, plant-derived fragments, and an appropriate amount of water were added to a beaker and thoroughly stirred with a spatula. Comparative Example 1, with a mixing ratio of 0% by mass, means that no mushroom fruiting body-derived fibers were added.

[0048] A Büchner funnel was inserted into the mouth of a suction flask, filter paper was set, and the mixture was poured in. After leveling the surface of the mixture with a spatula, water removal was promoted by suction from the flask with an aspirator. The Büchner funnel was removed from the flask, placed upside down, and then lifted to level the mixture into a disc shape approximately 3 cm in diameter and 1.5 cm thick. After further leveling the surface of the mixture with a spatula, the mixture was placed on an aluminum tray and dried in a constant temperature dryer set to 120°C for more than 12 hours. Through the above procedure, a plant-derived fragment molded body was produced. Figures 3A and 3B show photographs of the appearance of the molded body. Figures 4A and 4B show magnified photographs of the surface of the molded body of Example 1 (10 mass%) (Figure 4A is magnified at 100x, Figure 4B is magnified at 200x). Figures 4C and 4D show magnified images of the molded surface of Example 5 (50% by mass) (magnification: 100x for Figure 4C, 200x for Figure 4D). Figures 4E and 4F show magnified images of the molded surface of Example 8 (80% by mass) (magnification: 100x for Figure 4E, 200x for Figure 4F).

[0049] Comparative Example 1, which did not contain any mushroom fruiting body-derived fibers, barely maintained its shape because there was nothing to bind the plant fibers together. This molded body easily disintegrated upon contact.

[0050] In Examples 1-9, in which mushroom fruiting body-derived fibers were added, the plant fibers were bound together, and the molded bodies maintained their shape without collapsing when touched. When the molded bodies were observed under magnification, as illustrated in Figures 4A-4F, it was observed that relatively small mushroom fruiting body-derived fibers (white dotted arrows) were adhering to the fibers of each plant-derived fragment (black solid arrows) by cross-linking them. In addition, it was observed that relatively large mushroom fruiting body-derived fibers (white solid arrows) were intertwined, covering the fibers of each plant-derived fragment (black solid arrows). This binding method by large and small mushroom fruiting body-derived fibers was similar in all Examples 1-9, although not all are illustrated here.

[0051] However, in Examples 1 and 2, where the mixing ratio of mushroom fruiting body-derived fibers was relatively low, relatively small mushroom fruiting body-derived fibers were not observed in large numbers, and in particular, as shown in Figures 4A and 4B, almost none were observed in Example 1 (10% by mass). One possible reason for this is that relatively small mushroom fruiting body-derived fibers were lost along with the moisture during suction by the aspirator. However, this result indicates that a molded body that can maintain its shape can be formed even with only relatively large mushroom fruiting body-derived fibers (see also Figures 3A and 3B). In practical terms, by performing moisture removal slowly in the mixing step S01, it is possible to retain more relatively small mushroom fruiting body-derived fibers even when the mixing ratio of mushroom fruiting body-derived fibers is relatively low.

[0052] Furthermore, as is clear from comparing Example 1 (10% by mass), which has a relatively low mixing ratio of mushroom fruiting body-derived fibers as shown in Figures 4A and 4B, with Example 8 (80% by mass), which has a relatively high mixing ratio of mushroom fruiting body-derived fibers as shown in Figures 4E and 4F, the higher the mixing ratio of mushroom fruiting body-derived fibers, the more the mushroom fruiting body-derived fibers fill the gaps between the plant-derived fragments, forming a denser structure. As a result, for example, Examples 7, 8, and 9 felt noticeably harder and stronger when held in the hand than Examples 1 and 2.

[0053] On the other hand, since the mushroom fruiting body-derived fibers, which have a relatively high moisture content, tend to shrink during drying, the higher the mixing ratio of mushroom fruiting body-derived fibers, the more easily the molded body deformed after the drying process S02. As shown in Figure 3B, deformation began to occur when the mixing ratio of mushroom fruiting body-derived fibers reached 60% by mass or more, and the deformation tended to increase as the mixing ratio increased.

[0054] [Exam 2] Plant-derived fragment molded bodies were manufactured. For the mushroom fruiting body-derived fibers, an appropriate amount of water was added to the fruiting bodies of the enoki mushroom (Flammulina velutipes) and ground them in a household blender. For the plant-derived fragments, coarsely ground dried sorghum (Sorghum bicolor) stems and leaves were ground more finely in a household blender. The mixing ratio of mushroom fruiting body-derived fibers to plant-derived fragments in the dry matter ratio was set to 0% by mass (Comparative Example 2), 10% by mass (Example 10), 20% by mass (Example 11), 30% by mass (Example 12), 40% by mass (Example 13), 50% by mass (Example 14), 60% by mass (Example 15), 70% by mass (Example 16), 80% by mass (Example 17), and 90% by mass (Example 18).

[0055] In Test 2, following the same procedure as in Test 1, an appropriate amount of water was added to the mushroom fruiting body-derived fibers and plant-derived fragments and mixed. Then, the water was removed using a Büchner funnel, suction flask, and aspirator. After that, a specified amount of the mixture was filled into a rectangular box with external dimensions of 5 × 7 cm and a predetermined depth, and while compressed from above and below with double clips, it was dried in a constant temperature dryer set to 100°C until there was no change in mass. Through these operations, a rectangular plate-shaped molded body of plant-derived fragments was produced.

[0056] Figure 5 shows the maximum bending stress [N / mm²] of molded articles (Comparative Example 2 and Examples 10-18) with a mixing ratio of mushroom fruiting body-derived fibers ranging from 0 to 90% by mass, as determined by a three-point bending stress test. 2 The graph shows this. This maximum bending stress is an indicator of the strength of the molded article, and in all cases, a larger value indicates greater strength. As shown in Figure 5, the strength of the molded article increases with increasing mixing ratio of mushroom fruiting body-derived fibers, reaching a maximum between 30% and 50% by mass (Examples 12-14), then temporarily decreasing slightly, and then rising more sharply from a mixing ratio of 60% by mass (Example 15) onwards, reaching a maximum at a mixing ratio of 90% by mass (Example 18).

[0057] Furthermore, when similar tests were repeated using various plant-derived fragment molded bodies, it was found that, although there were discrepancies between the maximum and minimum values, the strength of the molded bodies increased with increasing mixing ratio of mushroom fruiting body-derived fibers, reaching a maximum at least before a mixing ratio of approximately 50% by mass. After that, it temporarily decreased slightly, and then began to increase more sharply than before, reaching its maximum in the example closest to 100% by mass. Therefore, in the following Test 3, in addition to confirming the above findings, the properties of the molded bodies up to a mixing ratio of approximately 50% by mass, where the strength temporarily decreases slightly, were investigated.

[0058] [Exam 3] Plant-derived fragment molded bodies were manufactured. For the mushroom fruiting body-derived fibers, an appropriate amount of water was added to the fruiting bodies of Enokitake mushrooms (Flammulina velutipes), which were then ground in a household blender and passed through a sieve with a mesh size of 1 mm. For the plant-derived fragments, coarsely ground dried stems and leaves of sorghum (Sorghum bicolor) were further ground in a household blender and passed through a sieve with a mesh size of 1 mm. Figure 6 shows a magnified photograph of the mushroom fruiting body-derived fibers used in this experiment 3 (magnification: 20x). The mushroom fruiting body-derived fibers in this experiment 3 were ground mushroom fruiting bodies with an average fiber width of 500 μm or less (approximately 270 μm).

[0059] The mixing ratio of mushroom fruiting body-derived fibers in the dry matter ratio of mushroom fruiting body-derived fibers to plant-derived fragments was set to 0% by mass (Comparative Example 3), 0.5% by mass (Example 19), 1% by mass (Example 20), 2% by mass (Example 21), 5% by mass (Example 22), 10% by mass (Example 23), 20% by mass (Example 24), 30% by mass (Example 25), 40% by mass (Example 26), and 50% by mass (Example 27), respectively.

[0060] In Test 3, following the same procedure as in Test 1, an appropriate amount of water was added to the mushroom fruiting body-derived fibers and plant-derived fragments and mixed. Then, the water was removed using a Büchner funnel, suction flask, and aspirator. After that, a specified amount of the mixture was filled into a box with external dimensions of 18 × 18 cm and a predetermined depth. To ensure more uniform drying conditions, a 2.3 kg weight was placed on top, and a pressure of approximately 0.7 kPa was applied from above. The box was then dried in a constant temperature dryer set to 100°C until there was no change in mass. Through these operations, a square plate-shaped molded body of plant-derived fragments was produced.

[0061] Comparative Example 3, which did not contain any mushroom fruiting body-derived fibers, barely maintained its shape because there was nothing to bind the plant fibers together. This molded body easily disintegrated upon contact.

[0062] In Examples 19-27, in which mushroom fruiting body-derived fibers were added, the plant fibers bound together, and the molded bodies maintained their shape without collapsing when touched. Even with relatively low mixing ratios of mushroom fruiting body-derived fibers, such as 0.5% by mass (Example 19) and 1% by mass (Example 20), molded bodies that could maintain their shape to the extent that they did not collapse when held in the hand were obtained. Furthermore, in terms of feel when held in the hand, the stability of the shape increased as the mixing ratio of mushroom fruiting body-derived fibers increased (Examples 21 and 22), and when the mixing ratio of mushroom fruiting body-derived fibers reached 10% by mass (Example 23), the stability of the shape was clearly even greater compared to 0.5% by mass (Example 19) and 1% by mass (Example 20), etc.

[0063] Figures 7A and 7B show magnified photographs of the surface of the molded body of Example 26 (40% by mass). As shown in Figure 7B (magnification: 200x), which has a higher magnification, it was observed that relatively small mushroom fruiting body-derived fibers (white dotted arrows) were adhering to each plant-derived fragment (black solid arrows) by cross-linking them. Also, as shown in Figure 7A (magnification: 50x), which has a lower magnification, it was observed that relatively large mushroom fruiting body-derived fibers (white solid arrows) were intertwined, covering each plant-derived fragment (black solid arrows). This binding mode by large and small mushroom fruiting body-derived fibers was similar in all Examples 19-27, although not all are illustrated here. However, as in Test 1, as the mixing ratio of mushroom fruiting body-derived fibers decreased, relatively small mushroom fruiting body-derived fibers were not observed as much, and in particular, they were hardly observed at mixing ratios of 10% by mass or less (Examples 19-23).

[0064] Figure 8 shows the maximum bending stress [N / mm²] of molded articles (Examples 21-27) with a mixing ratio of mushroom fruiting body-derived fibers ranging from 2% to 50% by mass, as determined by a three-point bending stress test. 2 ] and bending Young's modulus [N / mm 2 The graph shows the results. Both the maximum bending stress and the bending Young's modulus are indicators of the strength of the molded article, and a larger value for both indicates greater strength. Although the magnitude of the maximum bending stress itself differs between Test 2 and Test 3 due to differences in manufacturing conditions and sample size (thickness, etc.), the way it progresses is similar. As shown in Figure 8, the strength of the molded article increases as the mixing ratio of mushroom fruiting body-derived fibers increases (Examples 21-25), reaching a maximum at a mixing ratio of 40% by mass (Example 26). After that, the strength of the molded article decreases slightly, and at a mixing ratio of 50% by mass (Example 27), it is about the same as when the mixing ratio was 30-35% by mass.

[0065] Figure 9 shows a graph of the porosity [%] of molded articles (Examples 23-27) with a mixing ratio of mushroom fruiting body-derived fibers ranging from 10% by mass to 50% by mass, as determined by X-ray CT. As shown in Figure 9, the porosity of the molded article exceeded 90% at a mixing ratio of 10% by mass (Example 23), but decreased to approximately 85% at a mixing ratio of 20-40% by mass (Examples 24-26). Subsequently, the porosity of the molded article increased, exceeding 90% again at a mixing ratio of 50% by mass (Example 27).

[0066] The changes in strength and porosity of these molded bodies are thought to be due to the fact that, prior to a mixing ratio of approximately 50% by mass (for example, up to about 40% by mass in Test 3), the relatively large gaps between plant-derived fragments were filled by mushroom fruiting body-derived fibers, resulting in a decrease in porosity and an increase in strength. On the other hand, mushroom fruiting body-derived fibers, which have a relatively high water content, tend to form gaps when they shrink during drying, and the gaps caused by this become larger as the mixing ratio of mushroom fruiting body-derived fibers increases. Therefore, for the molded body as a whole, it is thought that at some point prior to a mixing ratio of approximately 50% by mass (for example, around 40% by mass in Test 3), the decrease in porosity peaked, and then, due to the expansion of gaps accompanying the shrinkage of mushroom fruiting body-derived fibers, the porosity began to increase again, resulting in a decrease in the strength of the molded body. Furthermore, at a mixing ratio of around 50% by mass, under relatively unstable conditions where mushroom fruiting body-derived fibers and plant-derived fragments with different strengths are mixed, stress tends to concentrate in areas where the weaker material is localized, which also contributes to a decrease in strength. Therefore, it is thought that the decrease in strength peaks at a mixing ratio of around 50% by mass (for example, around 50% by mass in Test 3), but a certain level of strength can still be maintained.

[0067] As is clear from the results of previous tests 1, 2, and 3, this decrease in strength is temporary. At a certain point after the mixing ratio of mushroom fruiting body-derived fibers reaches approximately 50% by mass (for example, around 60% by mass in tests 1 and 2), the effect of the denser structure due to the increase in the amount of mushroom fruiting body-derived fibers outweighs the effect of the shrinkage of the mushroom fruiting body-derived fibers, and thereafter the strength increases sharply. Consequently, the porosity of the entire molded body is also thought to decrease again, and the strength is maximized when the mixing ratio is closest to 100% by mass. Therefore, for example, by setting the mixing ratio of mushroom fruiting body-derived fibers in the range of 40-60% by mass, which is around 50% by mass, a unique molded body with a constant strength and a constant porosity can be obtained.

[0068] From the above, in terms of shape retention and strength of the resulting molded article, the lower limit of the mixing ratio of mushroom fruiting body-derived fibers is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 10% by mass or more. Furthermore, in terms of balancing the strength of the molded article with the usability of the binding component (the higher the ratio of mushroom fruiting body fibers, the stronger the molded article becomes, but the usability of the plant-derived fragments that are the binding component decreases), the upper limit of the mixing ratio of mushroom fruiting body-derived fibers is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. Moreover, as a range in which a molded article with specific properties possessing both a certain strength and a certain porosity can be obtained, the mixing ratio of mushroom fruiting body-derived fibers is preferably 40 to 60% by mass. [Explanation of symbols]

[0069] S01 Mixing process S02 Drying process

Claims

1. Using mushroom fruiting body-derived fibers as a binding agent to bind plant-derived fragments. A method for binding plant-derived fragments characterized by the following.

2. The aforementioned mushroom fruiting body-derived fibers are made from crushed mushroom fruiting bodies. A method for binding plant-derived fragments according to claim 1, characterized by the above.

3. The aforementioned mushroom fruiting body-derived fibers have an average fiber width of 500 μm or less. A method for binding plant-derived fragments according to claim 1 or claim 2, characterized by the above.

4. It contains mushroom fruiting body-derived fibers as a binding component. A plant-derived fragment binding composition characterized by the following.

5. The aforementioned mushroom fruiting body-derived fibers are made from crushed mushroom fruiting bodies. The plant-derived fragment binding composition according to claim 4, characterized by the above.

6. The aforementioned mushroom fruiting body-derived fibers have an average fiber width of 500 μm or less. A plant-derived fragment binding composition according to claim 4 or claim 5, characterized by the above.

7. The binding component, which is a fiber derived from mushroom fruiting bodies, and the component to be bound, which is a plant-derived fragment, are mixed together, the mixture is shaped into a predetermined form, and then dried. A method for producing a plant-derived fragment molded body characterized by the following.

8. The aforementioned mushroom fruiting body-derived fibers are made from crushed mushroom fruiting bodies. A method for producing a plant-derived fragment molded article according to claim 7, characterized by the above.

9. The aforementioned mushroom fruiting body-derived fibers have an average fiber width of 500 μm or less. A method for producing a plant-derived fragment molded article according to claim 7 or claim 8, characterized by the above.

10. The mushroom fruiting body-derived fibers and the plant-derived fragments are mixed in a dry matter ratio ranging from 0.5:99.5 to 60:

40. A method for producing a plant-derived fragment molded article according to claim 7 or claim 8, characterized by the above.

11. After cultivating mushrooms, the spent culture medium is mixed with mushroom fruiting bodies, plant-derived materials, and / or water as needed, then stirred and ground, the mixture is shaped into a predetermined form, and then dried. A method for producing a plant-derived fragment molded body characterized by the following.

12. It contains fibers derived from mushroom fruiting bodies and plant-derived fragments. A plant-derived fragment molded body characterized by the following.

13. The aforementioned mushroom fruiting body-derived fibers are made from crushed mushroom fruiting bodies. A plant-derived fragment molded body according to claim 12, characterized by the above.

14. The aforementioned mushroom fruiting body-derived fibers have an average fiber width of 500 μm or less. A plant-derived fragment molded body according to claim 12 or claim 13, characterized by the above.

15. The dry matter ratio of the mushroom fruiting body-derived fibers to the plant-derived fragments is in the range of 0.5:99.5 to 60:

40. A plant-derived fragment molded body according to claim 12 or claim 13, characterized by the above.

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