Method of manufacturing fiber reinforced resin, system of manufacturing fiber reinforced resin, and structure

Abstract

To provide a method of manufacturing a fiber reinforced resin capable of achieving desired physical properties.SOLUTION: A method of manufacturing a fiber reinforced resin comprises recovery step S1, cleaning step S2, crushing step S3, homogenizing step S4, pelletizing step S5, inspection step S6, first determination step S7, second determination step S8, mixing step S9, and manufacturing step S10. Among these steps, the inspection step S6 is a step of inspecting a fiber state being a state of fibers contained in a used fiber reinforced resin. The mixing step S9 is a step of mixing the used fiber reinforced resin, a matrix resin, and raw material fibers being a virgin material at a predetermined ratio in accordance with the fiber state. The manufacturing step S10 is a step of manufacturing a recycled fiber reinforced resin being a recycled fiber reinforced resin using a mixture obtained in the mixing step S9.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing fiber reinforced resin, a system for producing fiber reinforced resin, and a structure. [Background technology]

[0002] Attempts have been made to recycle fiber-reinforced resins. The technology described in Patent Document 1 is known as a technology related to the recycling of fiber-reinforced resins. The abstract of Patent Document 1 describes a method for regenerating glass fiber-reinforced thermoplastic resin by remelting and kneading the resin, which is characterized in that, when the blending amounts of (A) recycled glass fiber-reinforced thermoplastic resin, (B) non-regenerated thermoplastic resin, and (C) non-regenerated glass fiber are a, b, and c parts by weight, respectively, a+b+c=100, a>0, b>0, c≧0, and a / (b+c)<0.8 are satisfied, and the recycled glass fiber-reinforced thermoplastic resin (A) is supplied to a process in which the non-regenerated thermoplastic resin (B) is in a molten state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-120224 A Summary of the Invention [Problem to be solved by the invention]

[0004] Fiber reinforced resins have different fiber contents, different fiber lengths, etc., depending on, for example, the product in which they were used and the part in which they were used in the product. For this reason, the fiber state (fiber content, fiber length, fiber length distribution, etc.) of the fibers in the fiber reinforced resin varies depending on, for example, the used fiber reinforced resin that has been recovered. However, in the technology described in Patent Document 1, used thermoplastic resin, disaster-affected thermoplastic resin, and non-recycled glass fibers are mixed in a predetermined ratio without considering the fiber state (paragraph 0014). Therefore, the physical properties of a newly manufactured fiber reinforced resin (recycled fiber reinforced resin) using used fiber reinforced resin may not be the desired physical properties. The problem to be solved by the present disclosure is to provide a fiber-reinforced resin manufacturing method, a fiber-reinforced resin manufacturing system, and a structure that can achieve desired physical properties. [Means for solving the problem]

[0005] The manufacturing method of the fiber reinforced resin of the present disclosure includes an inspection step of inspecting the fiber state, which is the state of the fibers contained in the used fiber reinforced resin, a mixing step of mixing the used fiber reinforced resin, a base resin, and a virgin raw material fiber in a predetermined ratio according to the fiber state, and a manufacturing step of manufacturing a recycled fiber reinforced resin, which is a recycled fiber reinforced resin, using the mixture obtained in the mixing step. Other solutions will be described later in the description of the embodiment of the invention. Effect of the Invention

[0006] According to the present disclosure, it is possible to provide a fiber reinforced resin manufacturing method, a fiber reinforced resin manufacturing system, and a structure that can achieve desired physical properties. [Brief description of the drawings]

[0007] [Figure 1] 1 is a flowchart illustrating a method for producing a fiber reinforced resin according to the present disclosure. [Diagram 2] FIG. 1 is a diagram showing an example of a database that associates the required quality of recycled fiber reinforced resin with the fiber content and ratio. [Diagram 3]FIG. 13 is a diagram showing the results of an experiment to verify the effect of an elastomer. [Figure 4] FIG. 1 is a perspective view showing a structure of the present disclosure. [Diagram 5] 1 is an electron microscope photograph of a fiber-reinforced resin that does not use the first fiber derived from used fiber-reinforced resin, but uses only the second fiber derived from virgin material. [Figure 6] 6 is a graph showing the fiber length distribution in the fiber reinforced resin shown in FIG. 5. [Figure 7] 1 is an electron microscope photograph of recycled fiber-reinforced resin containing 40 mass % first fibers derived from used fiber-reinforced resin and 60 mass % second fibers derived from virgin materials. [Figure 8] 8 is a graph showing the fiber length distribution in the recycled fiber reinforced resin shown in FIG. 7. [Figure 9] 1 is a graph showing the fiber length distribution in a recycled fiber reinforced resin using only first fibers derived from used fiber reinforced resin without using second fibers derived from virgin materials. [Figure 10] FIG. 1 is a system diagram showing a fiber reinforced resin manufacturing system according to the present disclosure. [Figure 11] FIG. 2 is a block diagram showing a hardware configuration of a control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a form for carrying out the present disclosure (referred to as an embodiment) will be described with reference to the drawings. In the following description of one embodiment, other embodiments applicable to the one embodiment will also be described as appropriate. The present disclosure is not limited to the following one embodiment, and different embodiments can be combined with each other or modified as desired without significantly impairing the effects of the present disclosure. In addition, the same symbols will be used for the same members, and duplicate descriptions will be omitted. Furthermore, the same names will be used for members having the same functions. The contents shown are merely schematic, and for the sake of illustration, changes may be made from the actual configuration within a range that does not significantly impair the effects of the present disclosure, and some members may be omitted or modified between drawings. In addition, the same embodiment does not necessarily need to have all the configurations.

[0009] FIG. 1 is a flowchart showing a manufacturing method (hereinafter simply referred to as the manufacturing method of the present disclosure) of fiber reinforced resin (hereinafter appropriately referred to as "FRP") of the present disclosure. The manufacturing method of the present disclosure is a method of manufacturing new FRP using used FRP (hereinafter appropriately referred to as "used FRP"). In order to distinguish FRP newly manufactured using used FRP from used FRP, for convenience, FRP may be referred to as recycled fiber reinforced resin (hereinafter appropriately referred to as "recycled FRP"). Both used FRP and recycled FRP are one form of FRP. The manufacturing is performed by further using the same type of resin (base resin, for example, recycled resin) as the resin contained in the used FRP and the same type of fiber (raw fiber, for example, virgin material) as the fiber contained in the used FRP.

[0010] The manufacturing method of the present disclosure includes a recovery step S1, a washing step S2, a crushing step S3, a homogenization step S4, a pelletization step S5, an inspection step S6, a first determination step S7, a second determination step S8, a mixing step S9, and a manufacturing step S10. The manufacturing method of the present disclosure can be performed, for example, using a manufacturing system 100 (FIG. 10) described below.

[0011] The recovery step S1 is a step of recovering used FRP from, for example, a scrapyard or the like. FRP is a resin reinforced with fibers such as glass fiber, carbon fiber, and naturally derived fibers (such as cellulose nanofiber). The resin is, for example, a thermoplastic resin or a thermosetting resin. The used FRP is, for example, one that has been used in the structures of white goods such as washing machines, vehicles, industrial machines, and the like, but is not particularly limited.

[0012] The amount of fiber contained in the used FRP varies depending on, for example, the lot of the used FRP collected, the molded product made of the FRP, the manufacturer of the molded product, the manufacturing time of the product, etc. Thus, as will be described in detail later, in the manufacturing method disclosed herein, the amount of fiber contained in the collected FRP is determined. Then, based on the determined amount of fiber, the amount of used FRP used to manufacture the recycled FRP is determined. The form of the collected used FRP may be the same as the molded product made of the used FRP, or may be a molded product that has been appropriately crushed.

[0013] The cleaning step S2 is a step of cleaning the used FRP collected in the collection step S1. The cleaning may be performed on the used FRP that has been appropriately separated, for example, by size, type, etc. The cleaning can be performed using any cleaning liquid, such as water, an organic solvent (alcohol, etc.), etc.

[0014] The crushing step S3 is a step of crushing the used FRP washed in the washing step S2. The crushing produces flake-like used FRP. The degree of crushing is arbitrary, but it is preferable to crush to an extent that allows pelletization as described below, for example, and the material can be crushed to a size of, for example, 1 mm to 5 mm (the length of the longest part). Crushing can also be carried out, for example, for each lot of collected used FRP (for example, for each collection time or collection location, etc.).

[0015] The homogenization step S4 is a step of mixing the flakes from each lot obtained in the crushing step S3, for example, across lots. As described above, the fiber content is likely to vary from lot to lot for used FRP. Therefore, by mixing flakes from different lots and reweighing them at predetermined intervals, it is possible to reduce the large variation in the fiber content and homogenize the flakes. In the present disclosure, after suppressing the large variation in the fiber content by homogenization, the fiber state of the pellets (fiber content, etc.) is further inspected in the inspection step S6 described later.

[0016] The pelletizing step S5 is a step of producing pellets made of used FRP by crushing and molding the used FRP. In the pelletizing step S5, pellets of used FRP are obtained by molding (granulation) the flakes homogenized in the homogenizing step S4. The pellets have a cylindrical shape with a diameter of about 5 mm to 1 cm and a height of about 1 cm to 2 cm, for example, but the shape of the pellets is not limited to this.

[0017] The inspection process S6 is a process for inspecting the fiber condition, which is the state of the fibers contained in the used FRP. In the inspection process S6, the fiber condition of the pellets is grasped by inspecting the pellets obtained in the pelletizing process S5. The fiber condition grasped here (content rate, etc., described below) is used in the second determination process S8 described below.

[0018] The fiber condition includes the fiber content of the used FRP. Therefore, by inspecting the fiber condition in the inspection step S6, for example, the fiber content, which is the amount of fiber contained in a pellet per unit mass (or unit number), can be determined. Note that the fiber condition is not limited to the fiber content, and may be, for example, the fiber length, the fiber length distribution, or the degree of bending of the fiber.

[0019] The method for determining the fiber state, such as the fiber content, is not particularly limited. For example, the pellets can be destroyed (e.g., burned) and the content measured, or the fiber state can be determined by a non-destructive determination method, such as that described below.

[0020] The type of resin that makes up used FRP can be assumed to some extent, although it varies somewhat depending on the product that was made of FRP, the part in the product where the FRP was used, the application of the FRP, the manufacturer of the product, etc. Furthermore, the type of resin in used FRP can be determined more easily than determining the fiber content, for example, using a non-destructive method that uses an analytical device. Therefore, the physical properties and type of resin contained in used FRP can be estimated to some extent, and do not vary as much as the content. For this reason, the density of the resin contained in FRP can be easily grasped.

[0021] On the other hand, since FRP contains fibers, the density of FRP differs from the density of resin of exactly the same size as the FRP by the amount of the fibers. Since the content and density are correlated, the content can be determined by grasping the density. Specifically, for example, when a fiber having a density greater than that of the resin is contained, the higher the fiber content, the greater the overall density of the FRP. Therefore, by relating the content and the density of the FRP in advance, the content can be determined from the density of the FRP. Furthermore, the density of the FRP can be easily determined based on the mass and size (dimensions) of the FRP. Therefore, the content in used FRP can be easily determined in a non-destructive manner.

[0022] The content is preferably determined non-destructively as described above, but the content may also be determined by, for example, performing a combustion test or the like for each lot to burn off the resin and measure the amount of remaining fiber.

[0023] The first determination step S7 is a step of determining conditions including the fiber content rate Vf in the recycled FRP and the ratio φv of raw fiber (virgin material) to the total fiber in the recycled FRP so as to satisfy the required quality of the recycled FRP manufactured using the used FRP. Therefore, the fiber content rate Vf and the ratio φv are determined according to the target quality (target specifications) of a molded product (made of current FRP without using used FRP) used in a structure 20 (described later) such as a washing machine. The fiber content rate Vf in the recycled FRP is the content rate of all fibers (total fibers) in the recycled FRP, which is the fiber contained in the used FRP and the fiber (raw fiber) that is a virgin material to be newly used. The ratio φv is the ratio of raw fiber that is a virgin material to the total fiber.

[0024] Fig. 2 is a diagram showing an example of a database 11 that associates the required quality of the recycled FRP with the fiber content Vf and the ratio φv. In the example of Fig. 2, the database 11 is a graph G, but it may also be, for example, a table or a function. The unit of the fiber content Vf is, for example, mass%, and the unit of the ratio Vf is, for example, dimensionless. The database 11 is preferably created, for example, for each resin and each fiber.

[0025] In the database 11, the fiber content Vf and the value (1-φv) obtained by subtracting the ratio φv from 1 extend horizontally at right angles. In addition, an axis relating to the required quality of the recycled FRP extends vertically perpendicular to these axes. The required quality is an index that can be quantified. Point P is the case where used FRP is not included (i.e., in the recycled FRP, the ratio φv of raw fiber to total fiber is 1). Point Q is included together with point P on the horizontal plane S indicated by the two-dot chain line. Point P and point Q have the same required quality. Therefore, point Q is the quality of the recycled FRP that has the same required quality as the required quality of general FRP (point P). Point Q can also be said to be the intersection of graph G and horizontal plane S.

[0026] Graph G was created by actually creating FRPs with different combinations of fiber content Vf and ratio φv, and conducting tests (experiments) for each required quality of the FRP. Required qualities include tensile strength, which will be described below, as well as other characteristics such as tensile elongation, flexural strength, flexural modulus, impact strength (for example, at room temperature, below freezing, etc.), heat deformation temperature, melt flow rate, screw tightening torque, etc. Database 11 can be created, for example, for each type of required quality.

[0027] The recycled FRP manufactured by the manufacturing method disclosed herein is expected to be used for a desired purpose. Therefore, the quality required for the recycled FRP varies depending on the purpose. For example, when the recycled FRP is used for a purpose that requires high tensile strength, the required quality for the recycled FRP is a tensile strength of a certain level or more.

[0028] The required level of tensile strength can be determined by using a general FRP (using virgin resin and fiber) that does not use used FRP. What is determined here is the position of point P. This determines the position (height position) of the required quality extending in the height direction, and therefore the height direction position of horizontal plane S. Then, by determining the position of point Q, which is the intersection point of the determined horizontal plane S and graph G, the fiber content Vf and proportion φv corresponding to point Q can be determined.

[0029] Returning to Fig. 1, in the first determination step S7, a database 11 (Fig. 2) that associates the required quality of the recycled FRP with the fiber content Vf and the proportion Vf is used to determine the fiber content Vf and proportion Vf that correspond to the desired required quality. By using the database 11, it is possible to determine the fiber content Vf and proportion Vf that can achieve the required quality, and to manufacture recycled FRP that satisfies the required quality.

[0030] The second determination process S8 is a process for determining the mixing ratio of the used FRP, the base resin, and the virgin raw fiber material in the mixing process S9 based on the conditions (fiber content Vf and ratio Vf) determined in the first determination process S7.

[0031] As described above, the content of the used FRP is determined in the inspection step S6. The difference between the fiber content Vf, which is the target content of all fibers in the recycled FRP, and the ratio φv of the raw fiber to all fibers in the recycled FRP is the amount of fiber (recycled fiber) contained in the used FRP. Therefore, by determining the fiber content Vf and the ratio φv in the first determination step S7, the amount of used FRP containing fiber at the determined content, for example, pellets, can be determined. This allows the mixing ratio of the used FRP, the base resin, and the raw fiber in the mixing step S9 to be determined.

[0032] The mixing step S9 is a step of mixing used FRP, a base resin, and virgin raw fiber at a predetermined ratio according to the fiber state (for example, the fiber content in the pellet). The mixing conditions are not particularly limited, but are preferably conditions under which the resin and an appropriate elastomer (described later) can be melted and the resin, elastomer, and fiber can be kneaded. In the example of the present disclosure, the used FRP to be mixed is a pellet whose fiber content has been determined in the inspection step S6. The base resin used in the mixing step S9 has, for example, a pellet shape. Furthermore, the raw fiber is preferably in the form of a master batch in which it is kneaded in advance into the pellet-shaped base resin. However, the raw fiber may be mixed in a form separated from the base resin.

[0033] The amount of virgin raw fiber used is preferably 40% by mass or less of the total fibers contained in the recycled FRP. By keeping it in this range, the amount of long fiber contained in the recycled FRP can be relatively reduced. Since a large amount of long fiber tends to increase the shrinkage and expansion rates of the recycled FRP, by relatively reducing the amount of long fiber, excessive increases in the shrinkage and expansion rates can be suppressed.

[0034] In the mixing step S9, pellets formed from the used FRP, pellets of the base resin (e.g., master batch), and pellets (e.g., master batch) containing raw fiber in a resin (e.g., the same type of resin as the base resin) are mixed. Therefore, in the mixing step S9, the pellets produced in the pelletizing step S5 are mixed. This makes it easier to disperse the raw fiber throughout, and prevents uneven mixing. In addition, by mixing the base resin and raw fiber in the form of pellets, all the raw materials are mixed in a dry state (dry blended). This makes it possible to independently adjust the amounts of used FRP, base resin, and raw fiber used, making it easier to produce recycled FRP with the desired physical properties.

[0035] The base resin mixed in the mixing step S9 preferably contains recycled thermoplastic resin (e.g., polypropylene, polyethylene, polybutylene terephthalate, etc.). Both used FRP and recycled FRP contain the same type of resin. The resin contained therein is a thermoplastic resin, and among them, it is preferable that it is a recycled thermoplastic resin. By containing recycled thermoplastic resin, the amount of virgin thermoplastic resin used can be reduced, and the proportion of recycled material used in the recycled FRP can be increased. The recycled thermoplastic resin may be contained in the base resin pellets, or in the resin pellets containing fibers.

[0036] In the mixing step S9, it is preferable to further mix an elastomer. Elastomers have high elasticity. On the other hand, since the fibers derived from used FRP are short and brittle, physical properties such as impact strength may be lower than when long fibers are included. Therefore, by using an elastomer, the elasticity of the recycled FRP can be increased and the physical properties (impact strength) that have been reduced in this way can be restored.

[0037] The elastomer to be mixed is preferably in the form of pellets. By mixing the elastomer in pellet form, the elastomer can be easily dispersed throughout the recycled FRP, and local changes in the physical properties of the recycled FRP can be suppressed. The shape of the pellets can be, for example, columnar with a height of 2 mm to 3 mm and a diameter of 1 mm to 2 mm.

[0038] The amount of elastomer used can be, for example, 1.5% by mass to 15% by mass, and preferably 2.5% by mass to 15% by mass, based on the entire recycled FRP.

[0039] The type of elastomer may be one type or two or more types. The elastomer preferably includes a polypropylene-polyethylene elastomer. Since the polypropylene-polyethylene elastomer is widely used, the use of the polypropylene-polyethylene elastomer can reduce the manufacturing cost of the recycled FRP.

[0040] The elastomer preferably contains a hydrogenated ethylene-butadiene-styrene elastomer, which has hydrogen added to its double bonds, and therefore can suppress deterioration of the elastomer originating from the double bonds in the elastomer even after it is mixed with the recycled FRP.

[0041] The elastomer preferably includes an elastomer whose surface is modified with an acid. In the recycled FRP, the elastomer contacts the fiber at the surface of the elastomer. Therefore, the acid on the surface of the elastomer acts on the fiber, and the deterioration of the fiber surface can be restored. This improves the bonding strength between the elastomer and the fiber, and improves the durability of the recycled FRP. There are no particular limitations on the method of acid modification, but it can be performed by, for example, applying an acid such as maleic acid to at least the surface of the elastomer.

[0042] Fig. 3 is a diagram showing the results of an experiment to verify the effect of elastomer. The graph shown in Fig. 3 shows how the physical properties of FRP changed depending on whether or not an elastomer (polypropylene-polyethylene elastomer, Vistamaxx manufactured by ExxonMobil) was added. In Examples 1 to 3, the values ​​of each physical property in Reference Example 1 are shown as relative values, with the value of each property being 1.

[0043] The solid line (Reference Example 1) is the result for an FRP in which the ratio φv of raw fiber (virgin material) to the total fiber in the FRP is 1 (i.e., no used FRP is included). The widely spaced dashed line (Example 1) is the result for an FRP in which the ratio φv is 0.75 and no elastomer is included. The narrowly spaced dashed line (Example 2) is the result for an FRP in which the ratio φv is 0.75 and the elastomer content is 2.5 mass% relative to the entire FRP. The dotted line (Example 3) is the result for an FRP in which the ratio φv is 0.75 and the elastomer content is 10 mass% relative to the entire FRP.

[0044] The experiments were carried out on six physical properties: tensile strength at yield, tensile elongation at break, flexural strength, flexural modulus, and Izod impact strength (23°C, -10°C). Tensile strength at yield and tensile elongation at break were measured according to ASTM D638. Flexural strength and flexural modulus were measured according to ASTM D790. Izod impact strength (23°C, -10°C) was measured according to ASTM D256.

[0045] As shown in Figure 3, Examples 2 and 3, which used elastomer, were superior to Example 1, which did not use elastomer, in terms of, for example, Izod impact strength (23°C, -10°C). Therefore, it was found that the impact resistance strength can be improved by using elastomer. Furthermore, Examples 2 and 3 also had improved tensile elongation at break compared to Example 1.

[0046] Returning to FIG. 1, the manufacturing process S10 (molding process) is a process for manufacturing recycled FRP, which is recycled FRP, using the mixture obtained in the mixing process S9. The specific manufacturing method is not particularly limited, but for example, the mixture obtained in the mixing process S9 can be supplied to an injection molding machine (not shown) and molded using injection molding to obtain a molded product 21 (FIG. 4) made of recycled FRP. However, molding is not essential because the recycled FRP can be manufactured simply by cooling and solidifying the mixture obtained in the mixing process S9. In addition, the specific molding method is not limited to an injection molding machine, and any molding method such as extrusion molding can be used.

[0047] Fig. 4 is a perspective view showing a structure 20 of the present disclosure. The structure 20 includes a molded product 21 obtained by the manufacturing method of the present disclosure. In the example of Fig. 4, the structure 20 is a washing machine (washer / dryer), and the molded product 21 is a bellows. The bellows is required to have high impact resistance because it comes into contact with the laundry in the washing tub. For this reason, the bellows is made of, for example, FRP.

[0048] The molded product 21 contains fibers and resin derived from used FRP. In particular, for the fibers, unintentional changes in fiber length, fiber length distribution, degree of bending, etc. occur during the process of recovering used FRP and during each step (breaking, kneading, etc.) in the manufacturing method of the present disclosure. For this reason, it is not possible to specify the physical properties (fiber length, etc.) of the molded product 21, which is the final product. Therefore, in order to express the molded product 21, the molded product 21 is specified by the manufacturing method.

[0049] The structure 20 is not limited to a washing machine, and the molded product 21 is not limited to a bellows. For example, the molded product 21 is preferably a part that constitutes at least one type of structure 20, such as a washing machine, a vacuum cleaner, a refrigerator, a cooking appliance, or an air conditioner. These are products that are discarded in large quantities from households and the like, and therefore used FRP is easy to collect. Therefore, recycled FRP obtained from easily collected used FRP can be used again in these products, allowing the material to be recycled.

[0050] The molded product 21 is obtained by the manufacturing method of the present disclosure as described above, and contains used resin and fibers. Therefore, the appearance is likely to be different from that of a molded product using resin and fibers, both of which are virgin materials. Therefore, the molded product 21 is preferably disposed in a location that is unlikely to be seen by the user while the structure 20 is in use, or that the user does not consciously look at. This can suppress the occurrence of anxiety in the user due to the appearance (appearance) that may be different from that of normal FRP.

[0051] Recycled FRP contains first fibers derived from used FRP and second fibers derived from virgin materials, which are raw fibers. When comparing the fiber lengths of the first fibers and the second fibers, the first fibers, whose fiber length cannot be controlled due to being crushed or the like, tend to be shorter than the second fibers. Therefore, the fiber length distribution in recycled FRP is characteristic.

[0052] FIG. 5 is an electron microscope photograph of an FRP (general FRP, conventional FRP) that does not use the first fibers derived from used FRP, but uses only the second fibers derived from virgin materials. FIG. 5 is an image obtained by breaking the FRP and photographing the fracture surface. In order to exert the performance of the FRP obtained by imparting the performance attributable to the fibers to the resin, the fiber length becomes relatively long (for example, 500 μm or more). For this reason, as shown in FIG. 5, relatively long fibers, shown in white, protrude (expose) on the fracture surface.

[0053] FIG. 6 is a graph (frequency distribution diagram) showing the fiber length distribution in the FRP shown in FIG. 5. The horizontal axis is fiber length, and for example, the item "up to 500 μm" means fibers having a length of 1 μm to 500 μm. The higher the frequency, the higher the content in the FRP. The vertical axis is frequency (detection frequency). The frequency can be measured, for example, by removing the resin of the FRP by burning it or dissolving it in an arbitrary solvent, and then actually measuring the remaining fiber length. These points are the same in FIG. 8 and FIG. 9 described below.

[0054] As shown in Figure 6, the majority of fibers were between 501μm and 1000μm (or "up to 1000μm" in the item description), followed by fibers between 1μm and 500μm (or "up to 500μm" in the item description). Furthermore, fibers between 1001μm and 1500μm and between 1501μm and 2000μm were also present.

[0055] Figure 7 is an electron microscope photograph of a recycled FRP containing 40% by mass of first fibers derived from used FRP and 60% by mass of second fibers derived from virgin materials. The photograph was taken in the same manner as in Figure 5 above. However, compared to Figure 5 above, it can be seen that the length of the fibers protruding from the fracture surface is significantly shorter. That is, while in Figure 5 above, numerous white rod-shaped fibers can be seen protruding toward the front of the page, in Figure 7, such fibers are hardly visible.

[0056] Figure 8 is a graph showing the fiber length distribution in the recycled FRP shown in Figure 7. In the recycled FRP, the majority of fibers were 1μm to 500μm (in terms of the item, "up to 500μm"), followed by fibers 501μm to 1000μm (in terms of the item, "up to 1000μm"). In addition, fibers of 1001μm to 1500μm and 1501μm to 2000μm were also present. Therefore, the most common fiber length range was different from that in Figure 6 above.

[0057] Figure 9 is a graph showing the fiber length distribution in a recycled FRP that uses only the first fibers derived from used FRP, without using the second fibers derived from virgin materials. Unlike Figures 6 and 8 above, no fibers over 1001 μm were detected. In other words, the fiber length contained in the recycled FRP was 1000 μm or less, and among them, there were many fibers with a fiber length of 1 μm or more and 500 μm or less. In particular, the most common fibers were 201 μm or more and 300 μm or less (in terms of categories, "up to 300 μm").

[0058] As shown in Figures 6, 8, and 9 above, it was found that the use of used FRP (Figures 8 and 9) significantly increased the distribution of fiber lengths of 500 μm or less compared to when used FRP was not used (Figure 6). On the other hand, it was also found that the use of second fibers derived from virgin materials (Figure 8) and the use of second fibers (Figure 9) resulted in fibers with fiber lengths of 1000 μm or more remaining in the recycled FRP compared to when second fibers were not used. Therefore, if an FRP contains a mixture of first fibers with a fiber length of 500 μm or less and second fibers with a fiber length of 1000 μm or more, the FRP is found to be a recycled FRP. In other words, recycled FRP contains first fibers with a fiber length of 500 μm or less and second fibers with a fiber length of 1000 μm or more.

[0059] 10 is a system diagram showing a manufacturing system 100 for FRP according to the present disclosure. The manufacturing system 100 is a system for manufacturing new FRP using used FRP. The manufacturing method according to the present disclosure (FIG. 1) can be performed by the manufacturing system 100.

[0060] The manufacturing system 100 includes a recovery device 1, a cleaning device 2, a crushing device 3, a homogenizing device 4, a pelletizing device 5, an inspection device 6, a mixing device 9, and a manufacturing device 10. The manufacturing system 100 also includes a control device 13, which includes a database 11 and an arithmetic control unit 12. The manufacturing system 100 also includes a tank 14 for storing raw fiber, which is a virgin material, and an adjustment mechanism 15 for adjusting the amount of raw fiber supplied from the tank 14 to the mixing device 9. The raw fiber is stored in the tank 14 in the form of pellets containing fiber in the same type of resin as the resin stored in the tank 17. The manufacturing system 100 also includes a tank 17 for storing resin (e.g., recycled thermoplastic resin), and an adjustment mechanism 16 for adjusting the amount of resin supplied from the tank 17 to the mixing device 9. The manufacturing system 100 also includes an adjustment mechanism 18 for adjusting the amount of used FRP supplied to the mixing device 9.

[0061] The recovery device 1 is a device that recovers used FRP, for example, from a scrap collection site. The recovery device 1 is equipped with a transport device, for example, a belt conveyor. The recovery device 1 performs a recovery process S1 (Fig. 1). The cleaning device 2 is a device that cleans the FRP recovered by the recovery device 1. The cleaning device 2 performs a cleaning process S2 (Fig. 1). The crushing device 3 is a device that crushes the FRP cleaned by the cleaning device 2. The crushing device 3 performs a crushing process S3 (Fig. 1). The homogenization device 4 is a device that mixes flakes for each lot obtained by the crushing device 3. The homogenization device 4 performs a homogenization process S4 (Fig. 1).

[0062] The pelletizing device 5 is a device that manufactures pellets made of used FRP by crushing and molding the used FRP. The pelletizing device 5 executes a pelletizing process S5 (FIG. 1). The inspection device 6 is a device that inspects the fiber condition, which is the state of the fibers contained in the used FRP. The inspection device 6 determines, for example, the fiber content Vx in the pellets made of the used FRP. The determined Vx is input to the calculation control unit 12. The inspection device 6 executes an inspection process S6 (FIG. 1).

[0063] The mixer 9 is a device that mixes used FRP, base resin, and virgin raw fiber at a predetermined ratio according to the fiber state. In the example of FIG. 10, in the mixer 9, the mixing ratio of used FRP is x(-), the mixing ratio of raw fiber is y(-), and the mixing ratio of resin is z(-). x, y, and z are determined by the calculation control unit 12 using the fiber content rate Vf and the ratio φv read out from the database 11. The mixer 9 executes the mixing step S9 (FIG. 1). The manufacturing device 10 is a device that uses the mixture obtained in the mixer 9 to manufacture recycled FRP, which is recycled FRP. The manufacturing device 10 executes the manufacturing step S10 (FIG. 1).

[0064] The control device 13 (particularly the calculation control unit 12) executes the first determination step S7 and the second determination step S8. Therefore, the control device 13 uses the database 11 to determine conditions including the fiber content rate Vf (mass%) in the recycled FRP and the ratio φv(-) of the raw material fibers to the total fibers in the FRP so as to satisfy the required quality of the recycled FRP. Based on the determined conditions, the control device 13 also determines the mixing ratio (x, y, z) of the used FRP, the base resin, and the raw material fibers in the mixer 9 as described above.

[0065] If the fiber content in the used FRP determined by inspection device 6 is Vx (mass%) and the fiber content in the base resin (e.g., pellets, master batch) containing the raw fiber is Vy (mass%), then the following equations (1) to (3) hold.

[0066] x=(1-φv)×Vf / Vx…Equation (1) y = φv × Vf / Vy … Equation (2) z=1-(x+y) ... Equation (3)

[0067] Equation (1) for calculating the mixing ratio x is a relational expression between the ratio φv, the fiber content Vf, and the fiber content Vx. Equation (2) for calculating the mixing ratio y is a relational expression between the ratio φv, the fiber content Vf, and the fiber content Vy. The fiber content Vy can be determined when preparing the base resin containing the raw material fibers. Equation (3) for calculating the mixing ratio z is a relational expression between the mixing ratio x and the mixing ratio y.

[0068] Therefore, the control device 13 determines the mixing ratios x, y, and z, for example, using the database 11 and equations (1) to (3). Then, the control device 13 controls the adjustment mechanisms 15, 16, and 18 so that the mixing ratios become x, y, and z.

[0069] 11 is a block diagram showing a hardware configuration of the control device 13. The control device 13 is configured to include, for example, a central processing unit (CPU) 1001, a random access memory (RAM) 1002, a read only memory (ROM) 1003, an interface (I / F) 1004, a bus 1005, and the like. The CPU 1001, the RAM 1002, the ROM 1003, and the interface 1004 are connected, for example, via the bus 1005. The control device 13 is embodied by a predetermined control program (for example, the determination method of the present disclosure, the manufacturing method of the present disclosure) stored in the ROM 1003 being expanded in the RAM 1002 and executed by the CPU 1001. Signals and information are exchanged between the control device 13 and various devices (such as servers), an external network, and the like, in terms of hardware, through the interface 1004.

[0070] According to the manufacturing method and manufacturing system 100 of the present disclosure, it is possible to determine the fiber content Vf and the ratio φv corresponding to the required quality of the recycled FRP, for example by using the database 11. This makes it possible to determine the mixing ratios x, y, and z of the used FRP, the base resin, and the raw fiber material, which is the virgin material, based on the determined fiber content Vf and ratio φv. Then, it is sufficient to mix the materials according to the mixing ratios x, y, and z, and even if the fiber content of the used FRP varies, the physical properties (quality) of the recycled FRP can be easily achieved to the desired physical properties (quality). [Explanation of symbols]

[0071] 1 Recovery device 10 Manufacturing equipment 100 Manufacturing System 11 Database 12 Calculation control unit 13 Control device 14. Tank 15 Adjustment mechanism 16 Adjustment mechanism 17. Tank 18 Adjustment mechanism 2. Cleaning equipment 3 Crushing equipment 4 Homogenizer 5 Pelletizing Device 6 Inspection Device 9 Mixing Device S1 Recovery Process S10 Manufacturing Process S2 Cleaning Process S3 Crushing Process S4 Homogenization Process S5 Pelletizing Process S6 Inspection Process S7 First Decision Process S8 Second Decision Process S9 Mixing Process

Claims

1. An inspection step of inspecting a fiber state, which is a state of fibers contained in the used fiber reinforced resin; A mixing process of mixing the used fiber reinforced resin, the base resin, and the virgin raw material fiber in a predetermined ratio according to the fiber state; A manufacturing process for manufacturing a recycled fiber reinforced resin, which is a recycled fiber reinforced resin, using the mixture obtained in the mixing process. A method for producing a fiber-reinforced resin comprising the steps of:

2. In the mixing step, pellets obtained by molding the used fiber-reinforced resin, pellets of the base resin, and pellets containing the raw material fibers in the resin are mixed. The method for producing a fiber-reinforced resin according to claim 1 .

3. A pelletizing process for producing pellets composed of the used fiber reinforced resin by pulverizing and molding the used fiber reinforced resin, In the mixing step, the pellets produced in the pelletizing step are mixed. The method for producing a fiber-reinforced resin according to claim 2 .

4. A first determination step of determining conditions including a fiber content in the recycled fiber reinforced resin and a ratio of raw fiber to total fiber in the recycled fiber reinforced resin so as to satisfy the required quality of the recycled fiber reinforced resin; A second determination step of determining a mixing ratio of the fiber reinforced resin used in the mixing step, the base resin, and the raw material fiber based on the conditions determined in the first determination step. The method for producing a fiber-reinforced resin according to claim 1 .

5. The recycled fiber reinforced resin includes first fibers having a fiber length of 500 μm or less and second fibers having a fiber length of 1000 μm or more. The method for producing a fiber-reinforced resin according to claim 4 .

6. In the first determination step, a database in which the required quality of the recycled fiber reinforced resin, the fiber content, and the ratio are associated with each other is used to determine the fiber content and the ratio that correspond to the desired required quality. The method for producing a fiber-reinforced resin according to claim 4 .

7. The fiber state includes a content of the fiber contained in the used fiber-reinforced resin. The method for producing a fiber-reinforced resin according to claim 1 .

8. The matrix resin comprises recycled thermoplastic resin The method for producing a fiber-reinforced resin according to claim 1 .

9. In the mixing step, an elastomer is further mixed. The method for producing a fiber-reinforced resin according to claim 1 .

10. The elastomer has a pellet shape. The method for producing a fiber reinforced resin according to claim 9 .

11. The elastomer comprises a polypropylene-polyethylene elastomer. The method for producing a fiber reinforced resin according to claim 9 .

12. The elastomer comprises a hydrogenated ethylene-butadiene-styrene elastomer. The method for producing a fiber reinforced resin according to claim 9 .

13. The elastomer includes an elastomer whose surface is at least acid-modified. The method for producing a fiber reinforced resin according to claim 9 .

14. An inspection device that inspects the fiber condition, which is the condition of the fibers contained in the used fiber reinforced resin; A mixer that mixes the used fiber reinforced resin, the base resin, and the virgin raw fiber in a predetermined ratio according to the fiber state; A manufacturing apparatus for manufacturing a recycled fiber reinforced resin, which is a recycled fiber reinforced resin, using the mixture obtained in the mixing apparatus. A fiber reinforced resin manufacturing system comprising:

15. An inspection step of inspecting a fiber state, which is a state of fibers contained in the used fiber reinforced resin; A mixing process of mixing the used fiber reinforced resin, the base resin, and the virgin raw material fiber in a predetermined ratio according to the fiber state; and a manufacturing step of manufacturing a recycled fiber reinforced resin, which is a recycled fiber reinforced resin, using the mixture obtained in the mixing step. A structure characterized by:

16. The molded product is a component constituting at least one structure of a washing machine, a vacuum cleaner, a refrigerator, a cooking appliance, or an air conditioner.

16. The structure of claim 15.

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