Molded article and method for producing molded article

Abstract

This molded article 10 is a molded article of a fiber-reinforced composite material including: a resin material (11) that serves as a base material and can be melted or decomposed; and a knitted fabric base material (21) that is knitted so that knitted yarn (20) in a continuous state forms a shape corresponding to the resin material (11), is embedded in the resin material (11), and reinforces the resin material (11). The molded article (10) is configured so as to include, in at least a portion of a knitting yarn blank region (30) formed between an edge (23a) of the knitted fabric base material (21) and an edge (12a) of the molded article (10) when viewed in a thickness direction (X) of the molded article (10), a different fiber material (13) that is separate from the knitted fabric base material (21).

Description

Molded product and manufacturing method of molded product

[0001] The present invention relates to a molded article made of a fiber-reinforced composite material and a method for producing the molded article.

[0002] Conventionally, molded articles have been provided from fiber-reinforced composite materials using fiber materials such as carbon fiber and natural fiber as reinforcement materials. Recently, there has been an increasing demand for recycling fiber-reinforced composite materials from the viewpoint of effective utilization of resources. Patent Document 1 listed below discloses a fiber-reinforced composite material in which the fiber substrate is a knitted fabric and a thermoplastic resin is used as the matrix resin.

[0003] Japanese Patent Application Laid-Open No. 2021-133593

[0004] As in Patent Document 1, if a knitted fabric substrate in which a knitting yarn is knitted is used as a reinforcing material and a meltable or decomposable resin material is used as a matrix resin, the resin material can be melted or decomposed to separate the knitting yarn from the resin material, making it possible to reuse the knitting yarn. In this way, molded products of fiber-reinforced composite materials that use a meltable or decomposable resin material as a matrix resin and a knitting yarn as a reinforcing material have the advantage that the knitting yarn can be reused, and there is a growing need for utilizing such products.

[0005] Here, the molded article may have through-holes (functional holes) that function as screw holes, drainage holes, or the like in the product. When a molded article of a fiber-reinforced composite material using a knitted fabric substrate as a reinforcement material is drilled in the part containing the knitted fabric substrate with a drill or the like, the knitting yarn is cut, making it impossible to fully utilize the length of the knitting yarn, and the range of products that can be manufactured using the cut knitting yarn is limited. Meanwhile, there is a demand for recovering the knitting yarn while maintaining its length, thereby expanding the uses of the knitting yarn when it is reused.

[0006] Another possible method for forming through holes in molded articles using a knitted fabric substrate is to drill holes in portions of the molded article that do not contain a knitted fabric substrate and are composed only of resin material using a drill or the like. However, in molded articles of fiber-reinforced composite materials, portions of the molded article that do not contain a knitted fabric substrate and are composed only of resin material are more susceptible to cracking than portions that contain a knitted fabric substrate. Therefore, when attempting to drill holes to serve as functional holes such as screw holes or drainage holes using a drill or the like in portions that do not contain a knitted fabric substrate, the drilling operation must be performed carefully to avoid cracking and to avoid the knitted fabric substrate. Furthermore, when through holes are to function as screw holes in products after their formation, there is a demand for improved fastening strength. Therefore, there is a demand for strengthening the areas around through holes in molded articles of fiber-reinforced composite materials.

[0007] Furthermore, in order to make the product uniform in size or thickness, after the molded product is removed from the mold, a portion of the outer edge of the molded product (e.g., a flange portion) may be removed by grinding or cutting. Furthermore, when removing a portion of the outer edge of the molded product, the portion that does not contain the knitted fabric substrate and is made of only the resin material is more likely to crack than the portion that contains the knitted fabric substrate. Therefore, when attempting to remove the portion that does not contain the knitted fabric substrate, the removal work must be carried out carefully so as to avoid cracks and to avoid the knitted fabric substrate. Furthermore, there is a demand for improving the strength of the outer edge of the product after removing a portion of the outer edge of the molded product.

[0008] An object of the present invention is to provide a molded article in which the periphery of the through-hole and the outer end are reinforced while expanding the uses of the knitting yarn when reused, and a method for manufacturing the molded article.

[0009] The inventors of the present application have studied a configuration for providing a through hole in a molded article using a knitted fabric base material knitted with knitting yarn as a reinforcing material without breaking the knitting yarn, and for strengthening the area around the through hole. As a result, the inventors of the present application have discovered that if a molded article is formed by providing a hole in the knitted fabric base material and arranging a different fiber material separate from the knitted fabric base material in the portion of the knitted fabric base material that will become the hole (knitted fabric hole), and then providing a through hole in the portion that will become the knitted fabric hole after molding, the area around the through hole will become a portion that contains the different fiber material, thereby strengthening the area around the through hole and allowing the through hole to be provided without breaking the knitting yarn.

[0010] Furthermore, we have come to the realization that if a different fiber material is placed in a portion (the outer end of the molded product) that is outward from the outer edge of the knitted fabric base material to form a molded product, and the portion containing the different fiber material is removed after molding by grinding or cutting, the outer end of the molded product will become the portion containing the different fiber material, which will strengthen the outer end of the molded product, and will also allow us to remove part of the outer end without breaking the knitting yarn, thereby making the size and thickness of the molded product uniform.

[0011] Molded articles according to each aspect of the present invention, which have been completed based on the above findings, have the following configuration: (1) The molded article is a molded article of a fiber-reinforced composite material, which includes a base material, a meltable or decomposable resin material, and a knitted fabric substrate in which a continuous knitting yarn is woven to form a shape corresponding to the resin material and embedded in the resin material, reinforcing the resin material, and the molded article is configured so that a different fiber material that is separate from the knitted fabric substrate is included in at least a part of a knitting yarn blank region formed between an edge of the knitted fabric substrate and an edge of the molded article, as viewed in the thickness direction of the molded article.

[0012] In the molded product of (1) above, a region (knitting yarn blank region) containing no knitting yarn is formed in the resin material between the edge of the knitted fabric substrate and the edge of the molded product, and at least a portion of the knitting yarn blank region is configured to contain a different fiber material that is separate from the knitted fabric substrate. Therefore, the molded product described above can strengthen the periphery of the edge of the molded product (e.g., the periphery of the through-hole or the outer edge of the molded product). Furthermore, in the molded product described above (1), after the resin material is melted or decomposed, the knitting yarn can be recovered while maintaining its length, thereby expanding the uses of the knitting yarn when reused. Thus, the molded product described above (1) can achieve both expanded uses of the knitting yarn when reused and strengthening the periphery of the edge of the molded product.

[0013] According to one aspect of the present invention, the molded product can adopt the following configuration: (2) A molded product is the molded product described in (1) above, wherein the knitted fabric base material includes knitted fabric holes penetrating the knitted fabric base material, the molded product includes through holes that are smaller than the knitted fabric holes and are provided so as to penetrate the resin material in portions corresponding to the inside edges of the knitted fabric holes, and the molded product is configured such that, by providing the through holes in the knitted fabric holes, the knitted yarn blank region is formed inward from the edges of the knitted fabric holes and outward from the edges of the through holes as viewed in the thickness direction, and the different fiber material is included in at least a portion of the knitted yarn blank region.

[0014] In the molded product (2) above, the portion of the knitted fabric substrate that will become a hole and that surrounds the through hole (the knitting yarn blank region) contains a different fiber material that is separate from the knitted fabric substrate. Therefore, in the molded product (2) above, the periphery of the through hole can be strengthened. Furthermore, in the molded product (2) above, a through hole is provided in the portion of the knitted fabric substrate that will become a hole (the knitting yarn blank region). In other words, in the molded product (2) above, the through hole is formed in the molded product so as to avoid the knitting yarn and without cutting the knitting yarn. Therefore, in the molded product (2) above, after the resin material is melted or decomposed, the knitting yarn can be recovered while maintaining its length, allowing for expanded uses of the knitting yarn when reused. Thus, the molded product (2) above can achieve both expanded uses of the knitting yarn when reused and strengthening of the periphery of the through hole.

[0015] According to one aspect of the present invention, the molded article can have the following configuration: (3) The molded article is the molded article described in (1) above, configured such that the different fiber material is contained in at least a part of the knitting yarn blank region between the outer edge of the knitted fabric base material and the outer edge of the molded article.

[0016] In the molded product of (3) above, at least a portion of the knitting yarn blank region formed between the outer edge of the knitted fabric substrate and the outer edge of the molded product is configured to contain a different fiber material. Therefore, the molded product of (3) above can strengthen the outer edge of the molded product. Furthermore, in the molded product of (3) above, after the resin material is melted or decomposed, the knitting yarn can be recovered while maintaining its length, thereby expanding the uses of the knitting yarn when reused. In this way, the molded product of (3) above can realize both expanding the uses of the knitting yarn when reused and strengthening the periphery of the outer edge of the molded product.

[0017] According to one aspect of the present invention, the molded article can have the following configuration: (4) In the molded article described in any one of (1) to (3) above, the molded article is configured so that the different fiber material different from the knitted fabric base material is contained in at least a part of the knitting yarn blank region.

[0018] In the molded article of (4) above, a different fiber material different from the knitted fabric substrate is included in the knitting yarn blank region. Therefore, in the molded article of (4) above, it is easy to distinguish the knitted fabric substrate from the different fiber material after the resin material is melted or decomposed. As a result, in the molded article of (4) above, it is easy to remove the different fiber material from the knitted fabric substrate after the resin is melted or decomposed.

[0019] According to one aspect of the present invention, the molded article can have the following configuration: (5) In the molded article described in any one of (1) to (4) above, the molded article is configured so that the different fiber materials formed into an aggregate are included in at least a portion of the knitting yarn blank region.

[0020] According to the molded article of (5) above, the knitting yarn and the different fiber material can be easily separated after the resin material is melted or decomposed. Specifically, in the molded article of (5) above, the different fiber materials are in an aggregate, so that after the resin material is melted or decomposed, the different fiber materials can be easily removed all together from the knitting yarn. As a result, with the molded article of (5) above, the knitting yarn can be easily recovered after the resin material is melted or decomposed.

[0021] According to one aspect of the present invention, the molded product can have the following configuration: (6) In the molded product described in any one of (1) to (5) above, the molded product is configured such that the different fiber material included in the knitting yarn blank region is arranged to extend outside the knitting yarn blank region, thereby forming an overlapping region including the knitting yarn and the different fiber material.

[0022] In the molded article of (6) above, the vicinity of the edge of the knitted fabric base material (the edge of the knitted fabric hole or the outer edge of the knitted fabric base material) is a portion containing the knitting yarn and the different fiber material, and is reinforced by the two fiber materials (the knitting yarn and the different fiber material). As a result, with the molded article of (6) above, the periphery of the knitted fabric hole and the periphery of the outer edge can be reinforced.

[0023] According to one aspect of the present invention, the molded product can have the following configuration: (7) In the molded product described in (6) above, the molded product includes the different fiber material in at least a part of the knitting yarn blank region, and the different fiber material arranged in the knitting yarn blank region is arranged so as to reach the outside of the knitting hole, thereby forming the overlap region outside the knitting hole.

[0024] In the molded article of (7) above, the different fiber material is arranged from the inside to the outside of the knitted hole. Therefore, in the molded article of (7) above, the vicinity of the edge of the knitted hole becomes a portion that includes the knitting yarn and the different fiber material, and is reinforced by the two fiber materials (the knitting yarn and the different fiber material). As a result, the molded article of (7) above can reinforce the periphery of the edge of the knitted hole.

[0025] According to one aspect of the present invention, the molded product can have the following configuration: (8) In the molded product described in (6) above, the different fiber material is included in at least a portion of the knitting yarn blank region, and the different fiber material arranged in the knitting yarn blank region is arranged so as to reach a position overlapping with an outer end of the knitted fabric base material when viewed in the thickness direction, thereby forming the overlapping region.

[0026] In the molded product of (8) above, the different fiber material is arranged from the knitting yarn blank region to the outer edge of the knitted fabric substrate. Therefore, in the molded product of (8) above, the vicinity of the outer edge of the knitted fabric substrate is a portion including the knitting yarn and the different fiber material, and is reinforced by the two fiber materials (the knitting yarn and the different fiber material). As a result, the molded product of (8) above can strengthen the periphery of the outer edge of the knitted fabric substrate. For example, in a component such as a boat hull, when a flange portion having a brim-shaped cross section is formed at the outer edge, the flange portion is often cut to smooth the end surface, and there is a demand for strengthening it. Furthermore, for example, the flange portion is a joint portion with other components, and there is a demand for strengthening it.

[0027] The manufacturing method of a molded product according to each aspect of the present invention has the following configuration: In the manufacturing method of a molded product (9), in a setting step, a knitted fabric substrate is set in a mold, and a different fiber material that is separate from the knitted fabric substrate is set so as to be positioned between the edge of the knitted fabric substrate and the edge of the molded product as viewed in the thickness direction of the molded product, and in a molding step, a resin material is injected into the mold with the knitted fabric substrate and the different fiber material set, so that the molded product contains the different fiber material in at least a part of a knitting yarn blank region formed between the edge of the knitted fabric substrate and the edge of the molded product as viewed in the thickness direction of the molded product.

[0028] According to the manufacturing method (9) above, after the resin material is hardened, the molded product is reinforced with a different fiber material outside the outer edge or inside the inner edge of the knitted substrate. Therefore, the manufacturing method (9) above can strengthen the edge of the molded product (outside the outer edge or inside the inner edge of the knitted substrate) so that cracks are less likely to occur. Furthermore, in the molded product manufactured by the manufacturing method (9) above, after the resin material is melted or decomposed, the knitting yarn can be recovered while maintaining its length, allowing for expanded uses of the knitting yarn when reused. Thus, the manufacturing method (9) above can produce a molded product that can both expand the uses of the knitting yarn when reused and strengthen the edge of the molded product.

[0029] The manufacturing method of a molded article according to each aspect of the present invention has the following configuration: The manufacturing method of a molded article according to (10) further comprises a removing step of removing a part of the knitting yarn blank region.

[0030] According to the manufacturing method (10) above, after the resin material is cured, a portion of the knitting yarn blank region containing the different fiber material is removed. Therefore, in the manufacturing method (10) above, when a portion of the molded product is removed, the portion can be strengthened so that cracks are less likely to occur.

[0031] According to one aspect of the present invention, the method for manufacturing a molded product can employ the following configuration: (11) In the method for manufacturing a molded product described in (9) above, the knitted fabric base material has knitted fabric holes penetrating the knitted fabric base material, and the mold is provided with convex portions formed in a convex shape, and in the setting step, the knitted fabric base material is set in the mold so that the convex portions pass through the knitted fabric holes.

[0032] According to the manufacturing method of (11) above, the knitted fabric base material can be set on the mold by inserting the knitted fabric holes into the protrusions of the mold. In other words, according to the manufacturing method of (11) above, the knitted fabric holes can be used as positioning holes for the mold. As a result, the manufacturing method of (11) above can reduce the effort required for positioning when setting the knitted fabric base material on the mold.

[0033] The term "meltable or decomposable resin material" includes, for example, a resin material that can be melted by heating, a resin material that can be decomposed by chemical decomposition using chemicals, and a resin material that can be decomposed by superheated steam decomposition.

[0034] For example, thermoplastic resins are examples of resin materials that can be melted by heating. Furthermore, thermosetting resins are examples of resin materials that can be decomposed by chemical decomposition using chemicals or by superheated steam decomposition. The resin material may be, for example, one that can be recovered by melting or decomposition. Various thermoplastic resins can be selected, such as polyethylene, polypropylene, ABS resin, acrylic resin, and polyamide. Various thermosetting resins can be selected, such as epoxy resin, vinyl ester resin, and unsaturated polyester resin.

[0035] "Fiber material" refers to a fiber material that is used as a raw material without undergoing processing such as spinning. Specifically, fiber material refers to, for example, a fiber material that constitutes the knitting yarn of a knitted fabric substrate, or a fiber material that constitutes a different fiber material. Fiber material refers to, for example, a single fiber. Examples of fiber materials include natural fibers such as cotton, wool, and silk, as well as carbon fiber, amilad fiber, and glass fiber. Fiber materials can be classified into natural materials or chemical fibers, and short fibers or long fibers.

[0036] For reference, short fibers and long fibers are not clearly defined, but are recognized as follows in the textile industry. "Short fibers" are recognized as, for example, short, cotton-like fibers with a length of approximately 1 to 128 millimeters per fiber. "Long fibers" are recognized as, for example, continuous fibers with a length of 1,000 meters or more. Examples of short natural fibers include cotton and wool. Examples of long natural fibers include silk. Note that the recognition of whether something is a long fiber or a short fiber differs depending on the industry in which the fiber is used, and the explanation in this specification is merely a reference example.

[0037] A "braiding yarn" is, for example, a thread-like material (including a string-like material) that forms the stitches of a knitted fabric substrate. A braiding yarn, for example, includes at least one fiber material. A braiding yarn is, for example, formed by twisting multiple fiber materials into a thread-like shape. A braiding yarn may include, for example, one type of fiber material or multiple types of fiber materials. The thickness of the braiding yarn can be appropriately selected depending on, for example, the size and thickness of the molded product, the knitting machine used, etc. In this specification, any material that can be knitted using a knitting machine is referred to as a "braiding yarn" regardless of its thickness. That is, in this specification, "braiding yarn" includes both a thickness generally referred to as a "thread" and a thickness generally referred to as a "string." The braiding yarn used in the molded product or the manufacturing method for a molded product of the present invention may be any material that can be used as a reinforcing material to reinforce a resin material. For example, the type of fiber material that constitutes the braiding yarn can be selected from a variety of materials, such as natural fiber, carbon fiber, and amirad fiber.

[0038] "Continuous state" means, for example, that the knitting yarn is continuous from the start to the end. Note that "continuous knitting yarn" does not matter whether it is, for example, a single knitting yarn without a joint, or whether it has a portion (a joint) where multiple knitting yarns are connected. In other words, "continuous knitting yarn" also includes, for example, a knitting yarn with a joint along the way. The knitting yarn may be configured so that it can be handled as a single piece, for example. Furthermore, it does not matter whether the knitting yarn is, for example, a single piece, or multiple pieces bundled together.

[0039] A "knitted fabric substrate" is, for example, a substrate formed by continuously looping knitting yarns. More specifically, a knitted fabric substrate is, for example, a substrate formed by continuously looping knitting yarns, passing a knitting yarn through the looped portions to form further loops, and forming a knitted fabric by continuously looping the knitting yarns (stitches). The knitted fabric substrate can be formed, for example, using a knitting machine.

[0040] The knitted substrate may include, for example, a reinforcing material that does not form stitches. For example, the knitted substrate may include a reinforcing material other than the knitting yarn. That is, the knitted substrate may be composed of, for example, one type of reinforcing material or may include multiple types of reinforcing materials. For example, the knitted substrate may be composed of only the knitting yarn, or may include the knitting yarn and the inlay yarn. Furthermore, the knitted substrate may include other yarn materials (such as bias yarn) in addition to the knitting yarn.

[0041] Furthermore, the knitted fabric substrate may be, for example, one piece. Furthermore, the knitted fabric substrate may be, for example, a plurality of pieces. When a plurality of knitted fabric substrates are used, for example, the molded article may be one in which a plurality of knitted fabric substrates are arranged so as to conform to the shape of the molded article. Furthermore, for example, the molded article may be one in which a plurality of knitted fabric substrates are stacked and molded.

[0042] Furthermore, the knitted fabric substrate may be, for example, a single flat piece, or a single knitted fabric substrate knitted into a three-dimensional shape.

[0043] "So as to form a shape corresponding to the resin material" means, for example, that the knitting yarn forms the shape (skeleton) of the molded product. In other words, the knitting yarn is not, for example, used partially in the molded product, but rather forms the outer shape of the molded product. For example, "a knitted fabric substrate in which the knitting yarn is knitted to form a shape corresponding to the resin material and is embedded in the resin material" means that the knitted yarn is knitted to form the knitted fabric substrate, and the knitted fabric substrate has a shape that follows the shape of the molded product. "a knitted fabric substrate in which the knitting yarn is knitted to form a shape corresponding to the resin material and is embedded in the resin material" means that the knitted fabric substrate is used, for example, as a reinforcing material that reinforces the resin material that constitutes the molded product.

[0044] The "thickness direction" refers to a direction intersecting (e.g., perpendicular to) the surface of the molded article. For example, if the two surfaces of the molded article formed corresponding to the front and back of the knitted fabric substrate are designated as the first surface and the second surface, respectively, the thickness direction refers to a direction including a first direction from the second surface toward the first surface and a second direction from the first surface toward the second surface. Furthermore, if through holes are formed in the molded article, the thickness direction can be said to be the same as the direction in which the through holes penetrate (the penetration direction).

[0045] The "edge of a molded product" refers to, for example, the outline of the molded product when viewed in the thickness direction. The edge of a molded product includes, for example, the outer edge of the molded product. Furthermore, if a through hole is provided in the molded product, the edge of the through hole is included in the edge of the molded product.

[0046] The "edge of the knitted fabric substrate" is the outline of the knitted fabric substrate when viewed in the thickness direction. The edge of the knitted fabric substrate is the edge when the knitted fabric substrate, which is formed by knitting knitting yarns, is viewed as a single object. The edge of the knitted fabric substrate includes, for example, the outer edge of the knitted fabric substrate. Furthermore, when knitted fabric holes are provided in the knitted fabric substrate, the edges of the knitted fabric holes are included in the edge of the knitted fabric substrate. Furthermore, the edges of the knitted fabric holes can be said to be the inner edge of the knitted fabric substrate.

[0047] A "knitted fabric hole" is a portion of a knitted fabric substrate that is a hole that penetrates the knitted fabric substrate. For example, a knitted fabric hole is a hole in a knitted fabric substrate where there are no stitches and the knitting yarn is left blank, compared to a knitted fabric where stitches are densely packed. From another perspective, a knitted fabric hole is, for example, a hole in a knitted fabric substrate that is a gap larger than the gap between the stitches. From the opposite perspective, it can be said that the stitches are formed in the knitted fabric substrate so as to avoid the portion that will become the knitted fabric hole.

[0048] A "through hole" is a hole formed in a molded product so as to penetrate a resin material. For example, a through hole is a hole provided so as to penetrate two surfaces of a molded product. For example, a through hole is a hole provided so as to penetrate two surfaces that form the front and back of a molded product.

[0049] The through-hole may have a function in the molded product, for example. For example, the function of the through-hole can be selected from various options, such as a screw hole, a drainage hole, a hole for fitting a part, a window, etc. Furthermore, the through-hole may also constitute, for example, a pattern that appears on the exterior of the molded product.

[0050] The size and shape of the through holes can be selected as appropriate. For example, the through holes may have any opening shape, such as a circle, an elongated hole, a rectangle, or a keyhole. Furthermore, the through holes may have a diameter that changes in the thickness direction so as to be tapered, for example. Furthermore, the through holes may have any opening size, as long as it is smaller than the size of the knitted fabric holes. Furthermore, the opening size of the through holes may be larger than the size of one stitch, for example. Furthermore, the through holes may have a processed inner circumferential surface, for example. For example, the inner circumferential surface of the through holes may be threaded.

[0051] "A through hole provided to penetrate the resin material in a portion corresponding to the inside of the edge of the knitted fabric hole" means, for example, that the through hole is provided without overlapping with the edge of the knitted fabric hole. Also, "a through hole provided to penetrate the resin material in a portion corresponding to the inside of the edge of the knitted fabric hole" means, for example, that the through hole is provided inward from the edge of the knitted fabric hole. In other words, the through hole means, for example, that the through hole is provided to fit within the area that will become the knitted fabric hole. Also, "the through hole is smaller than the knitted fabric hole" means, for example, that the size of the opening of the through hole is smaller than the size of the opening of the knitted fabric hole.

[0052] A "knitting yarn blank region" is a portion of the resin material that does not contain a knitting yarn. The knitting yarn blank region is, for example, a portion that contains only a resin material, or a portion that contains a resin material and something other than a knitting yarn. The knitting yarn blank region may be a portion before a portion of the molded article is removed during the manufacturing process of the molded article, or a portion after a portion of the molded article has been removed. Furthermore, a molded article that includes a knitting yarn blank region may or may not be a molded article from which a portion of the molded article has been removed.

[0053] The knitting yarn blank region is, for example, the entire region in the thickness direction between the edge of the knitted fabric substrate and the edge of the molded article when viewed in the thickness direction. The knitting yarn blank region is, for example, the region inside the edge of the knitted fabric hole (the inner edge of the knitted fabric substrate) and outside the through hole (around the through hole of the molded article). Also, for example, the knitting yarn blank region is the region between the outer edge of the knitted fabric substrate and the outer edge of the molded article (the outer edge of the molded article).

[0054] The knitting yarn blank region is, for example, a region that is inward from the edge of the knitting hole and outward from the through hole when the molded product is viewed in the thickness direction, and is the entire region in the thickness direction. Furthermore, for example, "the entire region in the thickness direction" means, for example, the entire region from the first surface to the second surface. In other words, the knitting yarn blank region is, for example, a region that is inward from the edge of the knitting hole and outward from the through hole when the molded product is viewed in the thickness direction, and is the entire region from the first surface to the second surface. The knitting yarn blank region is, for example, a region sandwiched between the inner surface of the through hole and the inner surface of the knitting hole. Furthermore, the inner surface of the knitting hole is, for example, a virtual surface that includes the edge of the knitting hole and extends in the thickness direction. In other words, the inner surface of the knitting hole is a boundary surface that separates the knitted stitches from the knitting hole in the knitted fabric substrate.

[0055] The knitting yarn blank region is, for example, the entire region in the thickness direction that is located inside the edge (inner edge) of the knitting hole.

[0056] "At least a portion of the knitting yarn blank region contains a different fiber material" means that there are cases where the different fiber material is contained in the entire region of the knitting yarn blank region, and cases where the different fiber material is contained in only a portion of the knitting yarn blank region. For example, at least a portion of the entire region of the knitting yarn blank region may be a different fiber material-containing portion. For example, the knitting yarn blank region may have a different fiber material-containing portion and a resin material portion.

[0057] For example, the molded product of the present invention may include a different fiber material 13 in the entire knitting yarn blank region 30 (see Figures 3(b) and 5(b)). Also, for example, the molded product of the present invention may include a different fiber material 13, 43 in a portion of the knitting yarn blank region 30. For example, the molded product of the present invention may include a different fiber material 13, 43 in a portion of the thickness direction X of the knitting yarn blank region 30 (see Figures 1(b), 2(b), 4(b), and 6(b)). Also, for example, the molded product of the present invention may include a different fiber material 13 in a portion of the radial direction of the knitting yarn blank region 30 (see Figure 4(b)).

[0058] The molded article of the present invention, for example, comprises a braided yarn-containing portion which is a portion in a resin material that contains a braided yarn but does not contain a different fiber material. The molded article, for example, comprises a different fiber material-containing portion which is a portion in a resin material that contains a different fiber material but does not contain a braided yarn. The molded article may, for example, comprise a mixed portion which is a portion in a resin material that contains both a braided yarn and a different fiber material. The molded article may, for example, comprise a resin material portion which is a portion in a resin material that does not contain either a braided yarn or a different fiber material.

[0059] As described above, the knitting yarn blank region may include, for example, both a different fiber material-containing portion and a resin material portion. The knitting yarn blank region may be configured, for example, so that the different fiber material-containing portion and the resin material portion are aligned (layered) in the thickness direction. The knitting yarn blank region may be configured, for example, so that the different fiber material-containing portion and the resin material portion are layered in the radial direction of the through hole. The knitting yarn blank region may be configured, for example, so that the entire region is made up of a different fiber material-containing portion. In other words, the knitting yarn blank region may include, for example, a different fiber material-containing portion but not a resin material portion.

[0060] For example, one through-hole may be provided for one knitted hole, or multiple through-holes may be provided for one knitted hole. Furthermore, the through-holes may be provided so that their center lines coincide with the center lines of the knitted hole. Furthermore, the through-holes may be provided so that their center lines are offset from the center lines of the knitted hole.

[0061] "Dissimilar fiber material" refers to, for example, fiber material. Dissimilar fiber material refers to, for example, a single fiber. Dissimilar fiber material does not have continuity with, for example, the fiber material that constitutes the knitted substrate. Dissimilar fiber material can be, for example, a fiber material that is separate from the knitted substrate and is made of fiber material.

[0062] The dissimilar fiber material may be, for example, a filament-like single fiber. The dissimilar fiber material may be, for example, shorter than the knitting yarn that constitutes the knitted fabric substrate. The dissimilar fiber material may be, for example, thinner than the knitting yarn that constitutes the knitted fabric substrate. The dissimilar fiber material may be selected from various materials, such as natural fibers such as cotton, wool, and silk, carbon fiber, amilad fiber, and glass fiber.

[0063] The different fiber material may be, for example, the same type of fiber material as the fiber material constituting the knitted substrate. For example, both the fiber material constituting the knitted substrate and the different fiber material may be natural fibers. Furthermore, for example, both the fiber material constituting the knitted substrate and the different fiber material may be carbon fibers.

[0064] The dissimilar fiber material may be a fiber material of a different type from the fiber material constituting the knitted substrate. For example, the fiber material constituting the knitted substrate may be natural fiber, and the dissimilar fiber material may be resin fiber. Alternatively, the fiber material constituting the knitted substrate may be carbon fiber, and the dissimilar fiber material may be Amilado fiber. In this way, the dissimilar fiber material may be a fiber material used as a raw material that is different from the fiber material constituting the knitted substrate.

[0065] The different fiber material included in the knitting yarn blank region may be, for example, one fiber. For example, the different fiber material included in the knitting yarn blank region may be one single fiber. Also, the different fiber material included in the knitting yarn blank region may be, for example, multiple fibers. For example, the different fiber material included in the knitting yarn blank region may be multiple single fibers in a scattered state. Also, the different fiber material included in the knitting yarn blank region may be an aggregate of multiple single fibers (different fiber materials).

[0066] The term "dissimilar fiber materials formed into an aggregate" means, for example, that a plurality of dissimilar fiber materials are gathered together to form an aggregate. In this specification, dissimilar fiber materials formed into an aggregate may be referred to as a "dissimilar fiber material aggregate."

[0067] For example, when the dissimilar fiber material assembly is formed by twisting a plurality of dissimilar fiber materials into a thread, it may be thinner than the knitting yarn that constitutes the knitting yarn substrate. For example, when the dissimilar fiber material assembly is formed by twisting a plurality of dissimilar fiber materials into a thread, it may be shorter than the knitting yarn that constitutes the knitted fabric substrate. For example, the dissimilar fiber material assembly may be thinner (thinner) than the knitted fabric substrate. For example, the dissimilar fiber material assembly may be smaller in volume than the knitted fabric substrate.

[0068] The dissimilar fiber material assembly may include any type of dissimilar fiber material. For example, the dissimilar fiber material assembly may include one type of dissimilar fiber material, or may include multiple types of dissimilar fiber materials.

[0069] The dissimilar fiber material assembly can be selected from various forms, for example. The dissimilar fiber material assembly can be, for example, a sheet-like assembly formed by stacking dissimilar fiber materials. Examples of sheet-like dissimilar fiber material assembly include nonwoven fabrics in which dissimilar fiber materials are stacked, gauze in which dissimilar fiber materials are woven, and knitted fabrics in which knitting yarns in which dissimilar fiber materials are twisted are listed. The dissimilar fiber material assembly can also be, for example, a clump of dissimilar fiber materials. Examples of clumped dissimilar fiber material assembly include cotton, which is a single mass of cotton. In this way, the dissimilar fiber material assembly can be selected from various forms, such as woven fabrics, nonwoven fabrics, cotton, knitting yarns, knitting yarn scraps (cut knitting yarns), and knitted fabrics.

[0070] The dissimilar fiber material assembly may be, for example, a single sheet-shaped assembly, or may include a plurality of sheet-shaped assembly members.

[0071] The dissimilar fiber material assembly may be in a different form from the knitted substrate, for example. "The dissimilar fiber material assembly is in a different form from the knitted substrate" means that the form of the dissimilar fiber material assembly formed by assembling a plurality of dissimilar fiber materials is different from the form of the knitted substrate formed by assembling a plurality of fiber materials.

[0072] The following are examples of "a different fiber material assembly having a different configuration from the knitted fabric substrate." For example, a knitted fabric substrate is formed by knitting a knitting yarn in which fiber materials are twisted into a thread form, whereas a different fiber material assembly is formed by accumulating different fiber materials into a sheet form (for example, a nonwoven fabric in which different fiber materials are laminated into a sheet form). Also, for example, a knitted fabric substrate is formed by knitting a knitting yarn in which fiber materials are twisted into a thread form, whereas a different fiber material assembly is formed by accumulating different fiber materials into a single mass (for example, cotton).

[0073] Further examples of "the dissimilar fiber material aggregate has a different configuration from the knitted fabric substrate" include the following. For example, the dissimilar fiber material aggregate may be formed by twisting dissimilar fiber materials to form a knitting yarn that is thinner than the knitting yarn of the knitted fabric substrate, and the knitting yarn is knitted to form a knitted fabric. For example, the dissimilar fiber material aggregate may be formed by twisting dissimilar fiber materials to form a knitting yarn, and the knitting yarn is knitted to form a knitted fabric with a different stitch density than the knitted fabric substrate. For example, the dissimilar fiber material aggregate may be formed by twisting dissimilar fiber materials to form a knitting yarn, and the knitting yarn is knitted to form a knitted fabric with a higher stitch density than the knitted fabric substrate. For example, the dissimilar fiber material aggregate may be formed by twisting dissimilar fiber materials to form a knitting yarn, and the knitting yarn is knitted to form a knitted fabric with a different knitting method than the knitted fabric substrate.

[0074] The dissimilar fiber material assembly may be in the same form as the knitted fabric substrate, for example. "The dissimilar fiber material assembly is in the same form as the knitted fabric substrate" means, for example, that the dissimilar fiber material assembly is constructed using knitting yarn of the same thickness as the knitting yarn of the knitted fabric substrate, with stitches of the same size as the knitted fabric substrate, and in the same knitting method. In other words, "the dissimilar fiber material assembly is in the same form as the knitted fabric substrate" means that the dissimilar fiber material assembly is the same as the knitted fabric substrate in all of the knitting yarn thickness, stitch size, and knitting method. From the opposite perspective, if the dissimilar fiber material assembly differs from the knitted fabric substrate in any of the knitting yarn thickness, stitch size, and knitting method, this means that the dissimilar fiber material assembly is in a different form from the knitted fabric substrate.

[0075] The dissimilar fiber material assembly may have a density different from that of the fiber material of the knitted substrate. The dissimilar fiber material assembly may have a density higher than that of the fiber material of the knitted substrate. "The dissimilar fiber material assembly has a density higher than that of the fiber material of the knitted substrate" means, for example, that the volume of dissimilar fiber material per unit volume of the dissimilar fiber material assembly is higher than the volume of fiber material per unit volume of the knitted substrate. In other words, "The dissimilar fiber material assembly has a density higher than that of the fiber material of the knitted substrate" means, for example, that the proportion of dissimilar fiber material per unit volume of the dissimilar fiber material assembly is higher than the proportion of fiber material per unit volume of the knitted substrate. Explained from the opposite perspective, "the density of the dissimilar fiber material assembly is higher than the density of the fiber material of the knitted substrate" means, for example, that the proportion of things other than the dissimilar fiber material (e.g., air or resin material) per unit volume of the dissimilar fiber material assembly is lower than the proportion of things other than the fiber material (e.g., air or resin material) per unit volume of the knitted substrate. "The density of the dissimilar fiber material assembly is higher than the density of the fiber material of the knitted substrate" means, for example, that the proportion of things other than the dissimilar fiber material in the dissimilar fiber material assembly is lower than the knitted substrate, and there are fewer gaps between the dissimilar fiber materials.

[0076] If the dissimilar fiber material assembly is configured so that the density of the dissimilar fiber material is higher than the density of the fiber material of the knitted substrate, the gaps between the dissimilar fiber materials in the portion where the dissimilar fiber material assembly is arranged can be made smaller than in the portion containing the knitted substrate, and the dissimilar fiber material can be uniformly reinforced. As a result, after the resin material is melted or decomposed, it becomes easier to distinguish between the knitted substrate and the dissimilar fiber material and remove the dissimilar fiber material from the knitted substrate, and the area around the through hole (the knitting yarn blank area where the dissimilar fiber material is arranged) can be reinforced evenly.

[0077] An example of an "aggregate of different fiber materials in which the density of the different fiber materials is higher than the density of the fiber material of the knitted fabric substrate" is a knitted fabric having smaller stitches than the stitches of the knitted fabric substrate. An example of a knitted fabric having smaller stitches than the stitches of the knitted fabric substrate is a knitted fabric in which a knitting yarn thinner than the knitting yarn used in the knitted fabric substrate is used, and the stitches formed by the knitting yarn are smaller (finer stitches) than the knitted fabric substrate.

[0078] Examples of "a dissimilar fiber assembly in which the density of dissimilar fiber materials is higher than the density of the fiber material of the knitted substrate" include nonwoven fabrics, woven fabrics, cotton, and the like, in which the volume of dissimilar fiber materials per unit volume is higher than the volume of the fiber material in the knitted substrate. For example, in nonwoven fabrics, the dissimilar fiber materials constituting the nonwoven fabric are thinner than the knitting yarn and are laminated in a sheet shape so that the dissimilar fiber materials are in close contact with each other, so the gaps between the dissimilar fiber materials are often smaller than the gaps between the fiber materials (such as stitches) in the knitted substrate. In addition, for example, in woven fabrics, the dissimilar fiber materials are arranged vertically and horizontally, so the gaps between the dissimilar fiber materials are often smaller than in knitted fabrics. In addition, for example, in cotton, dissimilar fiber materials (single fiber cotton) that are thinner than the knitting yarn are entangled and aggregated so as to contain a lot of air. Therefore, when compressed to reduce the volume, the density of the dissimilar fiber materials may become higher than the density of the fiber material of the knitted substrate.

[0079] The dissimilar fiber material assembly may have a different uniformity of the dissimilar fiber materials than the uniformity of the fiber materials of the knitted fabric substrate. For example, the dissimilar fiber material assembly may have a higher uniformity of the dissimilar fiber materials than the uniformity of the fiber materials of the knitted fabric substrate. "Uniformity" refers to, for example, the degree of evenness of the distribution of the fiber materials. "High uniformity" refers to, for example, the degree of evenness of the distribution of the fiber materials. "High uniformity" refers to, for example, the fact that the fiber materials are evenly distributed.

[0080] "The dissimilar fiber material aggregate has a higher degree of uniformity of dissimilar fiber materials than the uniformity of the fiber materials of the knitted fabric substrate" means, for example, that the dissimilar fiber materials that make up the dissimilar fiber material aggregate are single fibers or threads that are thinner than the knitting yarns of the knitted fabric substrate, and that the dissimilar fiber materials are evenly distributed throughout the dissimilar fiber material aggregate.

[0081] The knitted fabric substrate is made by knitting a knitting yarn in which a plurality of fiber materials are twisted, and therefore includes portions where the fiber materials are bundled (knitting yarns) and portions where there are gaps (gaps between stitches, etc.). The knitted fabric substrate has a large bias in the fiber material between the portions where the fiber materials are concentrated and the portions where there are gaps.

[0082] Examples of "a heterogeneous fiber assembly in which the degree of uniformity of the heterogeneous fiber materials is higher than the degree of uniformity of the fiber materials of a knitted substrate" include nonwoven fabrics, woven fabrics, cotton, etc. For example, in nonwoven fabrics, the fiber materials constituting the nonwoven fabric are single fibers or threads thinner than knitting yarns, and the fiber materials are laminated in a sheet shape so that they are in close contact with each other, resulting in less bias and uniformity of the fiber materials compared to knitted substrates. Also, for example, in woven fabrics, thread-like fiber materials (thread materials) are woven so that they are aligned vertically and horizontally, and the gaps between the thread materials are uniform. Also, for example, in cotton, the cotton, which is a single fiber thinner than knitting yarn, is aggregated in an entangled manner, resulting in more uniformity of the cotton compared to knitted substrates.

[0083] If the dissimilar fiber material assembly is configured so that the dissimilar fiber material is more uniform than the knitted substrate, the portion where the dissimilar fiber material assembly is arranged can be reinforced more uniformly than the portion containing the knitted substrate. As a result, after the resin material is melted or decomposed, it becomes easier to distinguish between the knitted substrate and the dissimilar fiber material and remove the dissimilar fiber material from the knitted substrate, and the area around the through hole (the knitting yarn blank area where the dissimilar fiber material is arranged) can be reinforced evenly.

[0084] "Density" is, for example, the ratio of the volume of fiber material per unit volume of a knitted fabric substrate or an assembly of different fiber materials, while "uniformity" is, for example, the degree of uniformity of the fiber material in a knitted fabric substrate or an assembly of different fiber materials. In other words, for example, "density" is an index of whether a large amount of fiber material is contained, while "uniformity" is an index of whether the fiber material is evenly distributed (whether there is a large bias).

[0085] The dissimilar fiber material assembly may be formed, for example, in a shape that matches the opening shape of the knitted fabric hole, or in a shape different from the opening shape of the knitted fabric hole. For example, a circular dissimilar fiber material assembly may be used for a circular knitted fabric hole, or a rectangular dissimilar fiber material assembly may be used for a circular knitted fabric hole. Note that, for example, when an overlapping region is provided in a molded product using a sheet-shaped dissimilar fiber material assembly, it is preferable to use a dissimilar fiber material assembly that is larger than the size of the knitted fabric hole. This allows the dissimilar fiber material to be arranged so that it extends from the inside to the outside of the knitted fabric hole.

[0086] "The different fiber material contained in the knitting yarn blank area is arranged so as to extend outside the knitting yarn blank area" means, for example, that the different fiber material arranged in an area where no knitting yarn is arranged (knitting yarn blank area) is arranged so as to form a layer with the knitted fabric substrate from the knitting yarn blank area or to penetrate into the stitches of the knitted fabric substrate.

[0087] "The different fiber material arranged in the knitting yarn blank region is arranged so as to reach the outside of the knitting holes" means, for example, that the different fiber material arranged in part or all of the knitting yarn blank region is arranged so as to protrude from the region that will become the knitting holes (knitting yarn blank region). The different fiber material arranged in part or all of the knitting yarn blank region is arranged, for example, from the different fiber material-containing portion to the mixed portion.

[0088] "The different fiber material arranged in the knitting yarn blank region is arranged so as to reach the outside of the knitting hole" means, for example, if the different fiber material is a single fiber, that one different fiber material arranged in part or all of the knitting yarn blank region is arranged so as to protrude from the region that will become the knitting hole. "The different fiber material arranged in the knitting yarn blank region is arranged so as to reach the outside of the knitting hole" means, for example, if a different fiber material is an aggregate of multiple different fiber materials, that the different fiber material aggregate arranged in part or all of the knitting yarn blank region is arranged so as to protrude from the region that will become the knitting hole.

[0089] The "overlap region" is a region that includes a knitting yarn and a different fiber material. The overlap region is, for example, any of "a region where the knitting yarn and a different fiber material overlap when viewed in the thickness direction," "a region where the knitting yarn and a different fiber material are mixed," and "a region where the knitting yarn and a different fiber material overlap in the thickness direction and where the knitting yarn and a different fiber material are mixed."

[0090] An "overlapping region where the knitting yarn and the different fiber material overlap when viewed in the thickness direction" is, for example, a region in a molded product where a portion containing the knitting yarn and a portion containing the different fiber material are arranged so as to overlap when viewed in the thickness direction. Explained in more detail, an "overlapping region where the knitting yarn and the different fiber material overlap when viewed in the thickness direction" can be said to be, for example, a region where at least one knitting yarn-containing portion and at least one different fiber material-containing portion are arranged so as to line up in the thickness direction, and where the knitting yarn-containing portion containing the knitting yarn and the different fiber material-containing portion containing the different fiber material are arranged so as to overlap at least partially when viewed in the thickness direction.

[0091] The "overlapping region where the knitting yarn and the different fiber material are mixed" is a region in the molded product where the knitting yarn and the different fiber material are mixed. For example, the "overlapping region where the knitting yarn and the different fiber material are mixed" is a portion (mixed portion) embedded in the resin material so that the different fiber material is inserted into the stitches and the knitting yarn and the different fiber material are mixed.

[0092] The overlapping region may be configured, for example, such that a different fiber material-containing portion and a knitting yarn-containing portion form layers in the thickness direction. The overlapping region may be configured, for example, entirely of a mixed portion. The overlapping region may be configured, for example, such that a mixed portion containing a knitting yarn and a different fiber material and a different fiber material-containing portion form layers in the thickness direction. The overlapping region may be, for example, a region including a plurality of knitting yarn-containing portions. The overlapping region may be, for example, a region including a plurality of different fiber material-containing portions.

[0093] The molded article may be any part. For example, the molded article may be a boat part, a blade, a drone part, or the like. Furthermore, the molded article may be a finished product itself.

[0094] In the molded article of the present invention, the ratio (volume or weight ratio) of the resin material to the braiding yarn can be appropriately selected depending on, for example, the thickness and size of the molded article, the manufacturing method, and the like.

[0095] The method for producing a molded article of the present invention can be implemented by selecting from various techniques, for example, for setting a reinforcing material (e.g., a knitted fabric substrate) that has not been impregnated with resin in a mold and injecting resin. Examples of techniques for setting a reinforcing material in a mold and injecting resin include the RTM (Resin Transfer Molding) method. The RTM method involves setting a reinforcing material in a mold, closing a mold including an upper mold and a lower mold, injecting resin into a cavity in the mold, impregnating the reinforcing material with the resin in the mold, and allowing it to harden to form a molded article. The upper mold and lower mold include a film bag. That is, the RTM method includes a method in which a reinforcing material is placed between the upper mold or lower mold and the film bag and impregnated with resin.

[0096] The "removal process" is a process of removing a portion of the knitting yarn blank region. In the removal process, for example, a portion of the knitting yarn blank region is removed so that at least a portion of the different fiber material remains in the molded product. The removal process includes a through hole forming process in which a portion of the knitting yarn blank region inward from the edge of the knitted fabric hole is removed to form a through hole. The removal process also includes an outer end portion removing process in which a portion of the knitting yarn blank region outward from the outer edge of the knitted fabric base material is removed. In the outer end portion removing process, for example, the end face of the flange portion formed at the outer end portion of the molded product may be removed by grinding, cutting, or the like. Various methods can be selected to remove a portion of the molded product in the removal process (through hole forming process or outer end portion removing process), such as grinding, drilling, or cutting.

[0097] In the through-hole forming process, for example, through-holes smaller than the knitted fabric holes are formed so as to fit within the knitting yarn blank region. In the removing process, for example, a portion of the knitting yarn blank region is removed so that at least a portion of the different fiber material remains in the molded product. In other words, in the removing process, for example, a portion of the knitting yarn blank region is removed so that at least a portion of the different fiber material-containing portion included in the knitting yarn blank region remains in the molded product.

[0098] The knitted fabric substrate may be prepared in advance. Alternatively, the knitted fabric substrate may be formed using a knitting machine or the like in a substrate forming step that is performed before the setting step. In other words, the knitted fabric substrate may be formed at any time.

[0099] In the method for producing a molded article of the present invention, for example, in the setting step, the knitted substrate on which the different fiber material has been set in advance may be set in a mold. Also, in the method for producing a molded article of the present invention, in the setting step, the different fiber material may be set in the knitted holes or the outer end of the knitted substrate after the knitted substrate has been set in the mold. Also, for example, the different fiber material may be attached to the knitted substrate using an adhesive or the like, or may be set to the knitted substrate without using an adhesive or the like.

[0100] In the method for producing a molded article of the present invention, for example, different fiber materials may be set inside the knitted holes, or different fiber materials may be set so as to cover the knitted holes, or different fiber materials may be set inside the knitted holes and different fiber materials may be set so as to cover the knitted holes. Furthermore, in the method for producing a molded article of the present invention, for example, different fiber materials may be set outside the knitted substrate, or different fiber materials may be set so as to cover the outer edge of the knitted substrate, or different fiber materials may be set outside the knitted substrate and different fiber materials may be set so as to cover the outer edge of the knitted substrate. Furthermore, in the method for producing a molded article of the present invention, for example, one type of different fiber material may be set in one knitted hole, or two or more types of different fiber materials may be set in one knitted hole. Furthermore, in the method for producing a molded article of the present invention, for example, when a plurality of different fiber materials are gathered to form a different fiber material assembly, one different fiber material assembly may be set in one knitted hole, or two or more different fiber material assemblies may be set in one knitted hole.

[0101] A "protrusion" is, for example, a part of a mold formed in a convex shape. The protrusion may have any shape, as long as it is formed in a convex shape so as to raise a part of the mold. For example, when viewed in the thickness direction of the molded product, the protrusion may have any shape, such as a circle, an ellipse, an oval, or a rectangle. Furthermore, for example, the protrusion may have a rounded tip (a semicircular tip shape in cross-section), a rectangular tip, or a tapered shape that narrows in the radial direction toward the tip. Furthermore, the protrusion may be provided, for example, on the upper mold, the lower mold, or both the upper and lower molds.

[0102] The "protrusion" may be, for example, a part formed in advance in the mold, or may function as a protrusion by being set in the mold. For example, a core may be used as the protrusion.

[0103] The method for producing a molded article of the present invention may include steps other than the setting step, the molding step, and the removing step (the through-hole forming step or the outer end removing step). For example, the method for producing a molded article of the present invention may include a base material forming step of forming a knitted fabric base material by knitting a knitting yarn using a knitting machine, a deburring step of removing burrs around the through-holes, etc.

[0104] According to the present invention, it is possible to provide a molded article in which the periphery of the through-hole and the outer end are reinforced while expanding the uses of the knitting yarn when reused, and a method for manufacturing the molded article.

[0105] (a) is a plan view of a molded product according to a first embodiment of the present invention, (b) is a cross-sectional view taken along line A1-A1' in FIG. 1(a), (c) is an enlarged view of a main portion of FIG. 1(b), and (d) is a diagram showing the stitches of the knitted fabric substrate of the molded product of FIG. 1(a). (a) is a plan view of a molded product according to a second embodiment of the present invention, (b) is a cross-sectional view taken along line A2-A2' in FIG. 2(a), and (c) is an enlarged view of a main portion of FIG. 2(b). (a) is a plan view of a molded product according to a first example of the present invention, and (b) is a cross-sectional view taken along line A3-A3' in FIG. 3(a). (a) is a plan view of a molded product according to a second example of the present invention, and (b) is a cross-sectional view taken along line A4-A4' in FIG. 4(a). (a) is a plan view of a molded product according to a third example of the present invention, and (b) is a cross-sectional view taken along line A5-A5' in FIG. 5(a). 6(a) is a plan view of a molded product according to a fourth example of the present invention, and (b) is a cross-sectional view taken along line A6-A6' in FIG. 6(a). It is a flowchart showing a method for manufacturing the molded product of FIG. 1. It is a schematic diagram showing each step of the manufacturing method of FIG. 7. (a) is a setting step, (b) is a molding step, (c) is a through-hole forming step, and (d) is a molded product obtained after the through-hole forming step of FIG. 8(c). It is a schematic diagram showing each step of the manufacturing method of the molded product of FIG. 2. (a) is a setting step, (b) is a molding step, (c) is a through-hole forming step, and (d) is a molded product obtained after the through-hole forming step of FIG. 9(c). It is a flowchart showing a method for recovering knitting yarn from a molded product. (a) is a plan view of a molded product according to a third example of the present invention, (b) is a cross-sectional view taken along line A7-A7' in FIG. 11(a), and (c) is an enlarged view of a main portion of FIG. 11(b). It is a flowchart showing a method for manufacturing the molded product of FIG. 11. It is a schematic diagram showing each step of the manufacturing method of the molded product of FIG. 12. (a) is a setting step, (b) is a molding step, (c) is an outer edge removing step, and (d) is a molded product obtained after the outer edge removing step of Fig. 13(c). (a) is a plan view of a molded product according to a fourth embodiment of the present invention, (b) is a cross-sectional view taken along line A8-A8' in Fig. 14(a), and (c) is an enlarged view of a main part of Fig. 14(b).

[0106] Hereinafter, the details of the embodiment of the molded article and the manufacturing method of the molded article of the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example.

[0107] [First embodiment] First, a molded article 10 according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1(a) is a plan view of the molded article 10 according to the first embodiment of the present invention. Fig. 1(b) is a cross-sectional view taken along line A1-A1' in Fig. 1(a). Fig. 1(c) is an enlarged view of a main portion of Fig. 1(b). Fig. 1(d) is a diagram showing stitches 22 of a knitted fabric substrate 21 of the molded article 10 of Fig. 1(a).

[0108] The molded product 10 of this embodiment is a molded product of a fiber-reinforced composite material including a resin material 11 as a base material and a knitted fabric substrate 21 that reinforces the resin material 11. In the molded product 10 of this embodiment, a heat-meltable thermoplastic resin is used as the resin material 11. In addition, in the molded product 10 of this embodiment, natural fibers are used as the fiber material that constitutes the knitted fabric substrate 21. More specifically, the knitted fabric substrate 21 is formed by knitting knitting yarns 20 that are formed by twisting natural fibers into thread form.

[0109] Furthermore, the molded article 10 of this embodiment partially includes a dissimilar fiber material 13. In the molded article 10 of this embodiment, the dissimilar fiber material 13 is separate from the fiber material constituting the knitted fabric substrate 21. In addition, in the molded article 10 of this embodiment, the dissimilar fiber material 13 is cotton. Furthermore, in the molded article 10 of this embodiment, the dissimilar fiber material 13 (cotton in this embodiment) is an aggregate (e.g., cotton). More specifically, in the molded article 10 of this embodiment, a plurality of dissimilar fiber materials 13 are aggregated to form a dissimilar fiber material aggregate (cotton) formed in a block shape. As shown in FIG. 1( a), in the molded article 10 of this embodiment, the dissimilar fiber materials 13 are arranged so as to fill the substantially circular knitted fabric holes 23.

[0110] In the molded article 10, the resin material 11 is impregnated into the knitting yarn 20 and hardens to form a fiber-reinforced composite material using the knitting yarn 20 (knitted fabric substrate 21) as a reinforcement material. In other words, the molded article 10 has a portion containing the knitting yarn 20 in the resin material 11. The molded article 10 also has a portion containing the different fiber material 13 in the resin material 11.

[0111] In the description of the molded product of each embodiment below, a portion of the resin material 11 that does not contain both the braiding yarn 20 and the different fiber material (the different fiber material 13 or the different fiber material 43) may be referred to as a "resin material portion Ra." Also, a portion of the resin material 11 that contains the braiding yarn 20 but does not contain the different fiber material may be referred to as a "braiding yarn-containing portion Rb." Furthermore, a portion of the resin material 11 that contains the different fiber material but does not contain the braiding yarn 20 may be referred to as a "different fiber material-containing portion Rc." Furthermore, a portion of the resin material 11 that contains both the braiding yarn 20 and the different fiber material may be referred to as a "mixed portion Rd."

[0112] 1( a), a molded article 10 is provided with a through hole 12. In the following description of each embodiment, the two end faces of the molded article (resin material) where the through hole 12 is provided, on which the opening of the through hole 12 is located, may be referred to as a "first surface F1" and a "second surface F2," respectively.

[0113] In the following description of each embodiment, the thickness direction of the molded product may be simply referred to as the "thickness direction X." In addition, within the thickness direction X, the direction from the second surface F2 to the first surface F1 may be referred to as the "first direction X1," and the direction from the first surface F1 to the second surface F2 may be referred to as the "second direction X2." Furthermore, the direction intersecting the thickness direction X may be referred to as the "cross-sectional direction Y."

[0114] Furthermore, in the following description of each embodiment, the molded product viewed in the second direction X2 (thickness direction X) may be referred to as a "planar view." Also, the molded product viewed in the cross-sectional direction Y may be referred to as a "cross-sectional view."

[0115] Furthermore, in the description of each embodiment below, when the molded product is viewed in the second direction X2 (thickness direction X) (when viewed in a plan view), the region that is inward from the edge 23a of the knitted fabric hole 23 (the edge of the knitted fabric base material) and outward from the edge 12a of the through hole 12 (the edge of the molded product), and the entire region in the thickness direction X, may be referred to as the "knitting yarn blank region 30." In other words, the knitting yarn blank region 30 is the region that is outward from the edge 12a of the through hole 12 among the regions that are inward from the edge 23a of the knitted fabric hole 23 when the molded product is viewed in the thickness direction X, and is the portion that corresponds to the entire region in the thickness direction X of the molded product when viewed in the cross-sectional direction Y.

[0116] The knitting yarn 20 has a continuous thread-like shape and is configured as a knitted fabric substrate 21, which will be described later. That is, in the molded product 10, the knitting yarn 20 (knitted fabric substrate 21) is embedded in the resin material 11 over most of the molded product 10 that forms the outer shape of the product. In addition, in the molded product 10 of this embodiment, each knitted fabric substrate 21 has a three-dimensional shape that matches the shape of the molded product 10. As shown in FIG. 1(b), the molded product 10 of this embodiment includes one knitted fabric substrate 21.

[0117] The knitted fabric substrate 21 will be described in detail with reference to Fig. 1(d). In the following description, the direction in which the knitting yarn 20 is supplied (the horizontal direction in Fig. 1(d)) may be referred to as the "course direction B1", and the direction intersecting the course direction B1 (the vertical direction in Fig. 1(d)) may be referred to as the "wale direction B2".

[0118] As shown in Fig. 1(d), the knitting yarn 20 is formed in a loop shape, and the knitting yarn 20 is passed through the looped portion to sequentially form looped portions (stitches 22), resulting in a knitted substrate 21 with continuous stitches 22. Specifically, as shown in Fig. 1(d), the knitting yarn 20 forms a plurality of stitches 22 aligned in the course direction B1 in the knitted substrate 21. For example, the knitting yarn 20 forms a stitch 22a and a stitch 22b adjacent to the stitch 22a in the course direction B1 in the knitted substrate 21.

[0119] The knitting yarn 20 also forms a stitch 22c adjacent to the stitch 22a in the wale direction B2, and a stitch 22d adjacent to the stitch 22b in the wale direction B2. In this way, the knitting yarn 20 forms a plurality of stitches 22 in each of the course direction B1 and the wale direction B2, and is configured as a knitting base material 21. From another perspective, the knitting base material 21 forms a knitting path in which the knitting yarn 20 meanders, and the stitches 22 are formed so that the knitting yarn 20 is entangled.

[0120] As shown in Fig. 1(a), a knitted fabric hole 23 is provided in a knitted fabric substrate 21. As shown in Fig. 1(a), in the molded article 10 of this embodiment, the knitted fabric hole 23 has a substantially circular shape in a plan view.

[0121] The through holes 12 are provided so as to penetrate the molded article 10. As shown in Fig. 1(a) , in the molded article 10 of this embodiment, the through holes 12 have a substantially circular shape in a plan view. As shown in Fig. 1(b) , the through holes 12 are provided so as to be located inward of the edges 23a of the knitted fabric holes 23.

[0122] As shown in Fig. 1(b), the molded product 10 of this embodiment is configured to include a different fiber material 13 in a portion in the thickness direction X of the entire region of the knitting yarn blank region 30. Specifically, as shown in Fig. 1(c), in the molded product 10 of this embodiment, a portion in the thickness direction X (the middle portion in the thickness direction X) of the entire region of the knitting yarn blank region 30 is a different fiber material-containing portion Rc, and the other portion is a resin material portion Ra.

[0123] [Second embodiment] Next, a molded article 40 according to a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2(a) is a plan view of the molded article 40 according to the second embodiment of the present invention. Fig. 2(b) is a cross-sectional view taken along line A2-A2' in Fig. 2(a). Fig. 2(c) is an enlarged view of a main portion of Fig. 2(b).

[0124] The molded article 40 of this embodiment is a molded article of a fiber-reinforced composite material including a resin material 11 and a knitted fabric substrate 21. As shown in Fig. 2(b) , the molded article 40 of this embodiment includes one knitted fabric substrate 21.

[0125] The molded article 40 of this embodiment also includes a dissimilar fiber material 43 in part. The dissimilar fiber material 43 is separate from the fiber material constituting the knitted fabric substrate 21. In the molded article 40 of this embodiment, the dissimilar fiber material 43 is cotton. Furthermore, in the molded article 40 of this embodiment, the dissimilar fiber material 43 (cotton) is layered to form a nonwoven fabric. More specifically, in the molded article 40 of this embodiment, a plurality of dissimilar fiber materials 43 are assembled, and these are formed into a sheet-like dissimilar fiber material assembly (nonwoven fabric). As shown in FIG. 2( a), in the molded article 40 of this embodiment, the dissimilar fiber material 43 has a substantially rectangular shape large enough to cover the knitted fabric holes 23.

[0126] As shown in Fig. 2(a), the molded article 40 is provided with through holes 12. Also, as shown in Fig. 2(a), the knitted fabric base material 21 is provided with knitted fabric holes 23.

[0127] As shown in Fig. 2(b), the through-holes 12 are provided so as to penetrate the molded article 40. As shown in Fig. 2(a), in the molded article 40 of this embodiment, the through-holes 12 have a substantially circular shape in a plan view. As shown in Fig. 2(b), the through-holes 12 are provided so as to be located inward of the edges 23a of the knitted fabric holes 23.

[0128] As shown in Fig. 2(c), the molded product 40 of this embodiment is configured to include a different fiber material 43 in a portion in the thickness direction X of the entire region of the knitting yarn blank region 30. Specifically, as shown in Fig. 2(c), in the molded product 40 of this embodiment, a portion in the thickness direction X (a portion in the vicinity of the first surface F1) of the entire region of the knitting yarn blank region 30 is a different fiber material-containing portion Rc, and the other portion is a resin material portion Ra.

[0129] 2(b), the molded article 40 of this embodiment has an overlapping region 44. In the molded article 40 of this embodiment, the overlapping region 44 is configured such that the different fiber material 43 arranged in the knitting yarn blank region 30 reaches the outside of the knitting holes 23, so that the knitting yarn 20 and the different fiber material 43 overlap when viewed in the thickness direction X.

[0130] 2(c), in the molded article 40 of this embodiment, the different fiber material 43 is arranged so as to cover the knitted fabric hole 23, and the different fiber material 43 is arranged so as to reach the outside of the knitted fabric hole 23. As a result, an overlapping region 44 is formed outside the knitted fabric hole 23 of the molded article 40 when viewed in the thickness direction X, where a portion including the knitting yarn 20 (knitting yarn-containing portion Rb) and a portion including the different fiber material 43 (different fiber material-containing portion Rc) overlap. When viewed in the thickness direction X, the overlapping region 44 is an area where the knitting yarn-containing portion Rb and the different fiber material-containing portion Rc are arranged side by side in the thickness direction X, and is arranged so that the knitting yarn-containing portion Rb and the different fiber material-containing portion Rc overlap when viewed in the thickness direction X.

[0131] [First Example] Next, an example of a molded product of the present invention will be described with reference to Figures 3 to 6. In the following description of this example of the molded product, the same components as those of the molded product 10 of the first embodiment and the molded product 40 of the second embodiment will be designated by the same reference numerals as those used in these descriptions, and detailed description thereof will be omitted.

[0132] First, a molded article 50 according to a first example will be described with reference to Fig. 3. Fig. 3(a) is a plan view of the molded article 50 according to the first example of the present invention. Fig. 3(b) is a cross-sectional view taken along line A3-A3' in Fig. 3(a).

[0133] The first example is an example of a molded article 50 that includes a different fiber material 13 in the entire knitting yarn blank region 30. The molded article 50 is a molded article of a fiber-reinforced composite material that includes a resin material 11 and a knitting yarn 20 (knitted fabric substrate 21).

[0134] As shown in Fig. 3(a), the molded article 50 includes a portion of a different fiber material 13. As shown in Fig. 3(a), the molded article 50 has a through hole 12. Also, as shown in Fig. 3(a), the knitted fabric base material 21 has a knitted hole 23.

[0135] As shown in Fig. 3(b), the molded product 50 is configured so that the different fiber material 13 is contained in the entire knitting yarn blank region 30. In other words, the entire knitting yarn blank region 30 in the molded product 50 is a different fiber material-containing portion Rc.

[0136] [Second Example] Next, a molded product 60 according to a second example will be described with reference to Fig. 4. Fig. 4(a) is a plan view of a molded product 60 according to the second example of the present invention, and Fig. 4(b) is a cross-sectional view taken along line A4-A4' in Fig. 4(a).

[0137] The second example is an example of a molded article 60 that includes a different fiber material 13 in a radial portion of the knitting yarn blank region 30. The molded article 60 is a molded article of a fiber-reinforced composite material that includes a resin material 11 and a knitting yarn 20 (knitted fabric substrate 21).

[0138] As shown in Fig. 4(a), the molded article 60 includes a portion of a different fiber material 13. As shown in Fig. 4(a), the molded article 60 has a through hole 12. Also, as shown in Fig. 4(a), the knitted fabric base material 21 has a knitted hole 23.

[0139] 4(b), the molded product 60 is configured to include a different fiber material 13 in a portion of the knitting yarn blank region 30. To explain in more detail, in the molded product 60, of the entire area of ​​the knitting yarn blank region 30, a portion in the radial direction (inward in the radial direction) and a portion in the thickness direction X (middle portion in the thickness direction X) of the knitting yarn blank region 30 is a different fiber material-containing portion Rc, and the other portion is a resin material portion Ra.

[0140] [Third Example] Next, a molded product 70 according to a third example will be described with reference to Fig. 5. Fig. 5(a) is a plan view of a molded product 70 according to the third example of the present invention. Fig. 5(b) is a cross-sectional view taken along line A5-A5' in Fig. 5(a).

[0141] The third example is an example of a molded article 70 that includes the different fiber material 13 in the entire knitting yarn blank region 30 and has an overlap region 74 .

[0142] The molded article 70 is a molded article of a fiber-reinforced composite material including a resin material 11 and a knitting yarn 20 (knitted fabric substrate 21). As shown in Fig. 5(a), the molded article 70 partially includes a different fiber material 13. As shown in Fig. 5(a), the molded article 70 has a through-hole 12. Also, as shown in Fig. 5(a), the knitted fabric substrate 21 has a knitting hole 23.

[0143] As shown in Fig. 5(b), the molded product 70 is configured so that the different fiber material 13 is contained in the entire knitting yarn blank region 30. In other words, the entire knitting yarn blank region 30 in the molded product 70 is the different fiber material-containing portion Rc.

[0144] 5(b), the molded article 70 has an overlapping region 74. In the molded article 70, the overlapping region 74 is configured such that the different fiber material 13 arranged in the knitting yarn blank region 30 extends to the outside of the knitting holes 23, so that the knitting yarn 20 and the different fiber material 13 overlap when viewed in the thickness direction X.

[0145] 5(b), in the molded article 70, the different fiber material 13 is arranged so as to fill the knitted fabric holes 23, and the different fiber material 13 is arranged so as to reach the outside of the knitted fabric holes 23. As a result, an overlapping region 74 is formed outside the knitted fabric holes 23 of the molded article 70 when viewed in the thickness direction X, where a portion including the knitting yarn 20 (knitted yarn-containing portion Rb) and a portion including the different fiber material 13 (different fiber material-containing portion Rc) overlap. When viewed in the thickness direction X, the overlapping region 74 is an area where the knitted yarn-containing portion Rb and the different fiber material-containing portion Rc are arranged side by side in the thickness direction X, and where the knitted yarn-containing portion Rb and the different fiber material-containing portion Rc are arranged to overlap when viewed in the thickness direction X.

[0146] [Fourth Example] Next, a molded product 80 according to a fourth example will be described with reference to Fig. 6. Fig. 6(a) is a plan view of a molded product 80 according to the fourth example of the present invention. Fig. 6(b) is a cross-sectional view taken along line A6-A6' in Fig. 6(a).

[0147] The molded article 80 of the fourth example includes a mixed portion Rd (overlapping region 84) in which the knitting yarn 20 and the different fiber material 13 are mixed.

[0148] The molded article 70 is a molded article of a fiber-reinforced composite material including a resin material 11 and a knitting yarn 20 (knitted fabric substrate 21). As shown in Fig. 6(a), the molded article 80 partially includes a different fiber material 13. As shown in Fig. 6(a), the molded article 80 has a through-hole 12. Also, as shown in Fig. 6(a), the knitted fabric substrate 21 has a knitting hole 23.

[0149] As shown in Fig. 6(b), the molded product 80 is configured to include a different fiber material 13 in a portion in the thickness direction X of the entire area of ​​the knitting yarn blank region 30. Specifically, as shown in Fig. 6(b), in the molded product 80, a portion in the thickness direction X of the entire area of ​​the knitting yarn blank region 30 is a different fiber material-containing portion Rc, and the other portion is a resin material portion Ra.

[0150] 6(b), the molded article 80 has an overlapping region 84. In the molded article 80, the overlapping region 84 is a mixed portion Rd in which the knitting yarn 20 and the different fiber material 43 are mixed.

[0151] 6(b), in the molded article 80, the different fiber material 13 is arranged in the knitting hole 23, and the different fiber material 13 is mixed in the knitted fabric base material 21 outside the knitting hole 23. As a result, a mixed portion Rd is formed outside the knitting hole 23 of the molded article 80, where the knitting yarn 20 and the different fiber material 43 are mixed.

[0152] [Method for manufacturing molded article according to first embodiment] Next, a method for manufacturing the molded article 10 according to the first embodiment will be described with reference to Figs. 7 and 8. Fig. 7 is a flowchart showing the method for manufacturing the molded article 10. Fig. 8 is a schematic diagram showing each step of the method for manufacturing the molded article 10. Fig. 8(a) shows the setting step, Fig. 8(b) shows the molding step, Fig. 8(c) shows the through-hole forming step, and Fig. 8(d) shows the molded article 10 obtained after the through-hole forming step of Fig. 8(c). In this embodiment, an example will be described in which the molded article 10 is molded by the RTM method.

[0153] The molded article 10 is manufactured by setting the knitted fabric substrate 21 in a mold 110, and injecting and curing the resin material 11 into the mold 110. As shown in Fig. 8(a) , the knitted fabric substrate 21 has knitting holes 23 formed therein.

[0154] 7, the manufacturing method of this embodiment includes a setting step S100, a molding step S101, and a through-hole forming step S102. In this embodiment, the steps included in the manufacturing method of the molded product 10 are performed in the order of the setting step S100, the molding step S101, and the through-hole forming step S102.

[0155] As shown in Fig. 8(a), in the setting step S100, the knitted fabric substrate 21 and the different fiber material 13 are set in a mold 110. The mold 110 includes a lower mold 111 and an upper mold 112. As shown in Fig. 8(a), in the setting step S100, the knitted fabric substrate 21 is set along the mold 110 (the lower mold 111 in this embodiment) with the upper mold 112 and the lower mold 111 spaced apart from each other.

[0156] In the setting step S100, the different fiber material 13 is set so as to fill the knitted fabric holes 23. After the setting of the knitted fabric substrate 21 and the different fiber material 13 is completed, the mold 110 is closed. By closing the mold, a gap (cavity C) into which the resin material 11 is injected is formed in the mold 110. In addition, the knitted fabric substrate 21 is arranged in the cavity C of the mold 110 with the different fiber material 13 set in the knitted fabric holes 23.

[0157] 8(b), in the molding step S101, the knitted fabric substrate 21 and the different fiber material 13 are set and the mold is closed (in a mold-clamped state), and then the resin material 11 is injected into the cavity C. After the resin material 11 is injected into the cavity C, the resin material 11 hardens over time.

[0158] As described above, the cavity C of the mold 110 has the different fiber material 13 arranged in the knitting holes 23 of the knitted fabric base material 21. Therefore, in the molding step S101, a molded product 10A containing the different fiber material 13 is formed in a part of the region (knitting yarn blank region 30) that is inward from the edge 23a of the knitting holes 23 when viewed in the thickness direction X. After the resin material 11 has hardened, the mold is opened, and the molded product 10A with the different fiber material-containing portion Rc formed therein is removed from the mold.

[0159] As shown in Fig. 8(c), the knitting yarn blank region 30 includes a different fiber material-containing portion Rc. Specifically, as shown in Fig. 8(c), in the molded product 10A of this embodiment, the different fiber material-containing portion Rc is formed in a part of the entire knitting yarn blank region 30 in the thickness direction X (the middle part in the thickness direction X), and the other part is the resin material portion Ra.

[0160] In the through hole forming step S102, a through hole 12 is formed in the molded product 10A. Specifically, as shown in Fig. 8(c), in the through hole forming step S102, a hole is opened in the knitting yarn blank region 30 using a drill or the like. As a result, after the through hole forming step S102, a molded product 10 including a different fiber material 13 in the knitting yarn blank region 30 is obtained (see Fig. 8(d)).

[0161] [Method for manufacturing a molded article according to a second embodiment] Next, a method for manufacturing a molded article 40 according to a second embodiment will be described with reference to Fig. 9. Fig. 9 is a schematic diagram showing each step for manufacturing a molded article 40. Fig. 9(a) shows a setting step, Fig. 9(b) shows a molding step, Fig. 9(c) shows a through-hole forming step, and Fig. 9(d) shows a molded article obtained after the through-hole forming step of Fig. 9(c). In this embodiment, a case where the molded article 40 is molded by the RTM method will be described as an example.

[0162] The method for manufacturing the molded product 40 includes a setting step S100, a molding step S101, and a through-hole forming step S102, similar to the method for manufacturing the molded product 10. In this embodiment, the steps included in the method for manufacturing the molded product 40 are performed in the order of the setting step S100, the molding step S101, and the through-hole forming step S102.

[0163] As shown in Fig. 9(a), the mold 120 used in the manufacturing method of this embodiment includes a lower mold 121 and an upper mold 122. The mold 120 is provided with a convex portion 121a and a concave portion 122a. As shown in Fig. 9(a), the convex portion 121a is provided on the lower mold 121. The concave portion 122a is provided on the upper mold 122. When the mold 120 is clamped, the convex portion 121a is fitted into the concave portion 122a (see Fig. 9(b)).

[0164] As shown in Fig. 9(a), in the setting step S100, the knitted fabric substrate 21 and the different fiber material 43 are set on the mold 120. As shown in Fig. 9(a), in the setting step S100, the knitted fabric substrate 21 is set so as to be aligned with the mold 120 (the lower mold 121 in this embodiment) with the upper mold 122 and the lower mold 121 spaced apart. As shown in Fig. 9(a), in the setting step S100 of this embodiment, the knitted fabric substrate 21 is set on the lower mold 121 so that the knitted fabric holes 23 pass through the convex portions 121a. Also, as shown in Fig. 9(a), in the setting step S100 of this embodiment, after the knitted fabric substrate 21 is set on the lower mold 121, the different fiber material 43 is set so as to cover the convex portions 121a and the knitted fabric holes 23.

[0165] After the setting of the knitted fabric substrate 21 and the different fiber material 43 is completed, the mold 120 is clamped. By clamping the mold, a gap (cavity C) into which the resin material 11 is injected is formed in the mold 120. Furthermore, the knitted fabric substrate 21 is arranged in the cavity C of the mold 120 with the different fiber material 43 set so as to cover the knitted fabric holes 23.

[0166] 9(b), in the molding step S101, the knitted fabric substrate 21 and the different fiber material 43 are set and the mold is closed (mold-clamped state), and then the resin material 11 is injected into the cavity C. After the resin material 11 is injected into the cavity C, the resin material 11 hardens over time.

[0167] As described above, the different fiber material 43 is arranged in the cavity C of the mold 120 so as to cover the knitting hole 23 of the knitted fabric base material 21. Therefore, in the molding step S101, a different fiber material-containing portion Rc containing the different fiber material 43 is formed so as to extend from the knitting yarn blank region 30 inside the edge 23a of the knitting hole 23 in the thickness direction X to the outside of the knitting yarn blank region 30. After the resin material 11 has hardened, the mold is opened, and the molded product 40A with the different fiber material-containing portion Rc formed therein is removed from the mold.

[0168] Explaining in more detail, as shown in Fig. 9(c), a different fiber material-containing portion Rc is formed in the knitting yarn blank region 30. As shown in Fig. 9(c), in the molded product 40A of this embodiment, the different fiber material-containing portion Rc is formed in a part of the entire knitting yarn blank region 30 in the thickness direction X, and the other part is a resin material portion Ra. Also, as shown in Fig. 9(c), an overlapping region 44 is formed outside the knitting hole 23, where the knitting yarn-containing portion Rb and the different fiber material-containing portion Rc overlap when viewed in the thickness direction X.

[0169] In the through hole forming step S102, a through hole 12 is formed in the molded product 40A. Specifically, as shown in Fig. 9(c), in the through hole forming step S102, a hole is opened in the knitting yarn blank region 30 using a drill or the like. As a result, after the through hole forming step S102, a molded product 40 is obtained in which the knitting yarn blank region 30 contains a different fiber material 43 and an overlap region 44 is formed (see Fig. 9(d)).

[0170] [Material Recovery Method] Next, a method for recovering the knitting yarn 20 and the resin material 11 from the molded product 10 will be described. Fig. 10 is a flowchart showing the method for recovering the knitting yarn 20 from the molded product 10.

[0171] 10 , the process of recovering the knitting yarn 20 and the resin material 11 from the molded product 10 includes at least a heating step S200, a separating step S201, and a winding step S202. The steps for recovering the material of the molded product 10 are performed in the order of the heating step S200, the separating step S201, and the winding step S202. Note that the method of recovering the knitting yarn 20 and the resin material 11 from the molded product 10 may include other steps. For example, the method of recovering the knitting yarn 20 and the resin material 11 from the molded product 10 may include a step of gripping the terminal end of the knitting yarn 20.

[0172] In the heating step S200, a treatment is performed to heat the molded product 10. More specifically, in the heating step S200, the resin material 11 contained in the molded product 10 is heated to melt the resin material 11. In the heating step S200, the resin material 11 of the molded product 10 melts, making it possible to separate the knitting yarn 20 and the resin material 11.

[0173] In the separation step S201, a process is performed to separate the knitting yarn 20 from the resin material 11. Specifically, in the separation step S201, the knitting yarn 20 and the molten resin material 11 are separated by a centrifuge (not shown). After being separated, the knitting yarn 20 and the resin material 11 are each processed for reuse. The knitting yarn 20 is reused as the knitting yarn 20 again through a winding step S202 described below.

[0174] In the winding step S202, the stitches 22 of the knitted fabric substrate 21 are unraveled while pulling the end (not shown) of the knitting yarn 20, and the knitting yarn 20 is wound up. Here, in the molded product 10, since the through holes 12 are formed in the portions corresponding to the knitted fabric holes 23, the knitting yarn 20 is embedded in the resin material 11 without being cut. Therefore, after the resin material 11 is melted, the knitting yarn 20 is recovered while maintaining its length. This expands the uses of the recovered knitting yarn 20.

[0175] Third Embodiment Next, a molded article 130 according to a third embodiment of the present invention will be described with reference to Fig. 11. The molded article 130 of this embodiment is a molded article of a fiber-reinforced composite material including a resin material 11 and a knitted fabric substrate 21 that reinforces the resin material 11. The molded article 130 has a portion (knitted-yarn-containing portion Rb) that contains a braided yarn 20 in the resin material 11, and a portion (different fiber material-containing portion Rc) that contains a different fiber material 13 in the resin material 11.

[0176] As shown in Fig. 11(a), the molded product 130 contains the different fiber material 13 at the outer end 131 of the molded product 130. More specifically, as shown in Fig. 11(c), the molded product 130 contains the different fiber material 13 in a part of the knitting yarn blank region 30 between the outer edge 21a of the knitted fabric base material 21 and the outer edge 130a of the molded product 130. As shown in Fig. 11(c), in the molded product 130, of the entire region of the knitting yarn blank region 30, a part in the thickness direction X (the middle part in the thickness direction X) is a different fiber material-containing portion Rc, and the other part is a resin material portion Ra.

[0177] [Method for manufacturing molded product according to third embodiment] Next, a method for manufacturing the molded product 130 according to the third embodiment will be described. As shown in Fig. 12, the manufacturing method according to this embodiment includes a setting step S150, a molding step S151, and an outer edge removing step S152.

[0178] As shown in FIG. 13( a), in the setting step S150, the dissimilar fiber material 13 is set outward from the outer edge 21a of the knitted substrate 21. After the setting of the knitted substrate 21 and the dissimilar fiber material 13 is completed, the upper die 142 is brought close to the lower die 141, and the die 140 is closed. As shown in FIG. 13( b), by closing the die, a gap (cavity C) into which the resin material 11 is injected is formed within the die 140. As shown in FIG. 13( c), after the molding step S151, a molded product 130A including the dissimilar fiber material 13 is formed in a portion of the region (knitting yarn blank region 30) outward from the outer edge 21a of the knitted substrate 21. After the resin material 11 has hardened, the die is opened, and the molded product 130A including the dissimilar fiber material 13 in the knitting yarn blank region 30 is removed from the die.

[0179] As shown in Fig. 13(c), in the outer end portion removing step S152, a part of the knitting yarn blank region 30 is removed. As a result, after the outer end portion removing step S152, a molded product 130 is obtained that includes a part containing the different fiber material 13 in the knitting yarn blank region 30 (different fiber material-containing part Rc) (see Fig. 13(d)).

[0180] [Fourth embodiment] Next, with reference to Fig. 14, a molded product 160 according to a fourth embodiment of the present invention will be described. The molded product 160 of this embodiment is a molded product of a fiber-reinforced composite material including a resin material 11 and a knitted fabric substrate 21. As shown in Fig. 14(b), the molded product 160 of this embodiment includes one knitted fabric substrate 21. The molded product 160 of this embodiment also includes a dissimilar fiber material 43 in a portion thereof. As shown in Fig. 14(a), in the molded product 160 of this embodiment, the dissimilar fiber material 43 is arranged at an outer end portion 161. As shown in Fig. 14(c), in the molded product 160, of the entire region of the knitting yarn blank region 30, a portion in the thickness direction X is a dissimilar fiber material-containing portion Rc, and the remaining portion is a resin material portion Ra.

[0181] 14(b), the molded product 160 of this embodiment has an overlapping region 44. In the molded product 160 of this embodiment, the overlapping region 44 is configured such that the different fiber material 43 arranged in the knitting yarn blank region 30 reaches the outside of the knitting yarn blank region 30 (the outer end of the knitted fabric substrate 21), thereby overlapping the knitting yarn 20 and the different fiber material 43 as viewed in the thickness direction X. More specifically, as shown in FIG. 14(c), in the molded product 160 of this embodiment, the different fiber material 43 is arranged so as to cover the outer edge 21a of the knitted fabric substrate 21, and is also arranged so as to reach the outside of the knitting yarn blank region 30. As a result, an overlapping region 44 is formed at the outer end 161 of the molded product 160 as viewed in the thickness direction X, where a portion including the knitting yarn 20 (knitting-yarn-containing portion Rb) and a portion including the different fiber material 43 (different fiber material-containing portion Rc) overlap.

[0182] REFERENCE SIGNS LIST 10 Molded object 10A Molded object 11 Resin material 12 Through hole 12a Edge (edge ​​of molded object) 13 Dissimilar fiber material 20 Knitting yarn 21 Knitted fabric base material 21a Outer edge (edge ​​of knitted fabric base material) 22 Knit stitch 23 Knitted fabric hole 23a Edge of knitted fabric hole (edge ​​of knitted fabric base material) 30 Knitted yarn blank area 40 Molded object 40A Molded object 43 Dissimilar fiber material 44 Overlapping area 50 Molded object 60 Molded object 70 Molded object 74 Overlapping area 80 Molded object 84 Overlapping area 110 Mold 120 Mold 121a Convex portion S100 Setting process S101 Molding process S102 Through hole forming process (removal process) 130 Molded object 130a Outer edge (edge ​​of molded object) 160 Molded object 160a Outer edge (edge ​​of molded product) S150 Setting step S151 Molding step S152 Through hole forming step (removal step) X Thickness direction

Claims

1. A molded product of a fiber-reinforced composite material comprising: a base material, a resin material that can be melted or decomposed; and a knitted fabric substrate in which a continuous knitting yarn is woven to form a shape corresponding to the resin material and embedded in the resin material, reinforcing the resin material, wherein the molded product is configured so that a different fiber material that is separate from the knitted fabric substrate is included in at least a portion of the knitting yarn blank area formed between the edge of the knitted fabric substrate and the edge of the molded product when viewed in the thickness direction of the molded product.

2. A molded product as described in claim 1, wherein the knitted fabric base material includes a knitted fabric hole penetrating the knitted fabric base material, and the molded product includes a through hole that is smaller than the knitted fabric hole and is provided so as to penetrate the resin material at a portion corresponding to the inside of the edge of the knitted fabric hole, and by providing the through hole in the knitted fabric hole, the knitted yarn blank area is formed inward from the edge of the knitted fabric hole and outward from the edge of the through hole when viewed in the thickness direction, and the knitted yarn blank area is configured so that at least a portion of the knitted yarn blank area contains the different fiber material.

3. A molded product as described in claim 1, wherein the knitting yarn blank area is formed between the outer edge of the knitted fabric base material and the outer edge of the molded product when viewed in the thickness direction, and the different fiber material is contained in at least a portion of the knitting yarn blank area.

4. A molded product according to any one of claims 1 to 3, wherein the molded product is configured so that at least a portion of the knitting yarn blank region contains the different fiber material that is different from the knitting base material.

5. A molded product according to any one of claims 1 to 4, wherein the molded product is configured so that the different fiber materials are contained in an aggregate in at least a portion of the knitting yarn blank region.

6. A molded product according to any one of claims 1 to 5, wherein the molded product is configured such that the different fiber material contained in the knitting yarn blank area extends outside the knitting yarn blank area, thereby forming an overlapping area containing the knitting yarn and the different fiber material.

7. A molded product as described in claim 6, wherein the knitted fabric base material includes a knitted fabric hole penetrating the knitted fabric base material, the molded product includes a through hole that is smaller than the knitted fabric hole and is arranged to penetrate the resin material at a portion corresponding to the inside of the edge of the knitted fabric hole, the different fiber material is included in at least a portion of the knitted yarn blank area, and the different fiber material arranged in the knitted yarn blank area is arranged so as to reach the outside of the knitted fabric hole, thereby forming the overlapping area outside the knitted fabric hole.

8. A molded product as described in claim 6, wherein the different fiber material is contained in at least a portion of the knitting yarn blank region, and the different fiber material arranged in the knitting yarn blank region is arranged so that it reaches a position where it overlaps with the outer end of the knitted fabric base material when viewed in the thickness direction, thereby forming the overlapping region.

9. A method for manufacturing a molded product, comprising: a setting step of setting a knitted fabric substrate, which is made of a continuous knitting yarn, in a mold; and a molding step of injecting a resin material that serves as a base material and can melt or decompose, into the mold in which the knitted fabric substrate is set, thereby impregnating the knitted fabric substrate with the resin material and forming a molded product, wherein in the setting step, the knitted fabric substrate is set in the mold, and a different fiber material that is separate from the knitted fabric substrate is set so as to be positioned between the edge of the knitted fabric substrate and the edge of the molded product when viewed in the thickness direction of the molded product; and in the molding step, the resin material is injected into the mold with the knitted fabric substrate and the different fiber material set, so that the molded product is configured to include the different fiber material in at least a portion of the knitted yarn blank area formed between the edge of the knitted fabric substrate and the edge of the molded product when viewed in the thickness direction of the molded product.

10. The method for manufacturing a molded product according to claim 9, further comprising a removing step of removing a portion of the knitting yarn blank region.

11. A method for manufacturing a molded product according to claim 9, wherein the knitted fabric base material has knitted fabric holes penetrating the knitted fabric base material, the mold is provided with convex portions formed in a convex shape, and in the setting step, the knitted fabric base material is set in the mold so that the knitted fabric holes pass through the convex portions.

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