Fiber-reinforced resin molded body and manufacturing method thereof

Abstract

To provide a method capable of manufacturing an appealing resin molded body without increasing environmental load from a fiber product and a resin product which should be recycled.SOLUTION: A manufacturing method for a fiber-reinforced resin molded body includes: sorting steps S2A, S2B of sorting a fiber product and a resin product to be used as materials, according to predetermined sorting rules, from fiber products and resin products which should be recycled; a mixing step S3 of mixing the materials sorted in steps S2A, S2B with a predetermined ratio; and a molding step S4 of molding the materials mixed in step S3 in a predetermined shape. The sorting rules have been set to sort the fiber product and the resin product having a color included in a color range including target colors, and the color range is defined by, for example, an inner angle of Munsell hue ring.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fiber-reinforced resin molding comprising a fiber product and a resin product to be recycled, and a method for producing the same. [Background technology]

[0002] In order to achieve the Sustainable Development Goals (SDGs), efforts are being made to reuse various materials. Naturally, various studies are being made on the reuse of textile products. For example, Non-Patent Document 1 proposes using textile products that should be reused, called "used fibers," as reinforcing agents for resins.

[0003] The reuse of plastic products is also progressing: for example, according to a report by the PET Bottle Recycling Promotion Council, the reuse rate of PET bottles in Japan in recent years has exceeded 85%. On the other hand, the reuse of PET bottle caps (hereinafter simply referred to as "caps") has hardly progressed at all.

[0004] In view of this situation, the present inventor came up with the idea of ​​producing a new resin molded body reinforced from a used cap by using a textile product to be reused. However, textile products and caps come in a variety of colors. Therefore, it is thought that simply combining these products will only produce a molded body that is unattractive, with a dull color or that appears to have uneven coloring. This will not accelerate the reuse of textile products and caps.

[0005] However, if bleaching and dyeing processes are performed before molding, colorful and attractive molded products can be produced. However, bleaching and dyeing processes have a high environmental impact. For this reason, performing such processes goes against the spirit of the SDGs. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Motoko Uchimaru and 3 others, “Color Changes during Molding of Fiber-Reinforced Plastic Products Using Color-Sorted Waste Fibers”, Textile Product Consumption Science, Japan Textile Product Consumption Science Society, October 2015, Vol. 56, No. 10, pp. 819-825 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method capable of producing attractive resin molded bodies from textile products and resin products to be reused without increasing the environmental burden, and a resin molded body produced by the method. [Means for solving the problem]

[0008] In order to solve the above problems, the manufacturing method of the present invention is a method for manufacturing a fiber-reinforced resin molded body having a target color, and includes a sorting process for selecting fiber products and resin products to be used as materials from fiber products and resin products to be reused in accordance with predetermined sorting rules, a mixing process for mixing the materials selected in the sorting process in a predetermined ratio, and a molding process for molding the materials mixed in the mixing process into a predetermined shape, wherein the sorting rules stipulate that fiber products and resin products having colors included in a color range including the target color are selected.

[0009] The color range can be defined, for example, by the interior angle of the Munsell hue circle (for example, 85 to 105°).

[0010] The resin product is, for example, a cap for a used PET bottle.

[0011] The ratio by weight of the materials mixed in the mixing step is preferably fiber product:resin product=20:80 to 40:60.

[0012] It is preferable that the above-mentioned manufacturing method does not include a step of decolorizing at least one of the fiber product and the resin product before the mixing step, and a step of decolorizing the material before the molding step.

[0013] Preferably, the manufacturing method does not include a step of dyeing the material prior to the molding step.

[0014] In addition, in order to solve the above-mentioned problems, the fiber-reinforced resin molded product of the present invention is a resin molded product having a target color, and is manufactured by carrying out a sorting process in which fiber products and resin products to be used as materials are selected from the fiber products and resin products to be reused in accordance with predetermined sorting rules, a mixing process in which the materials selected in the sorting process are mixed in a predetermined ratio, and a molding process in which the materials mixed in the mixing process are molded into a predetermined shape, and the sorting rules stipulate that fiber products and resin products having colors included in a color range including the target color are selected.

[0015] In this specification, the term "textile products" includes textile products such as used clothing, as well as textile waste generated during the manufacturing process of textile products. In addition, in this specification, the term "resin products" includes resin products such as used caps (e.g., caps of PET bottles for storing beverages, caps of various containers for storing seasonings, detergents, etc.), as well as resin waste generated during the manufacturing process of resin products (e.g., scraps generated during the molding process). Effect of the Invention

[0016] According to the present invention, it is possible to provide a method for producing an attractive resin molded body from textile products and resin products to be reused without increasing the environmental burden, and a resin molded body produced by the method. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a flow diagram showing a method for producing a fiber-reinforced resin molded product according to the present invention. [Diagram 2]FIG. 2 is a diagram for explaining the selection rules used in the fiber product selection step and the resin product selection step of the manufacturing method for a fiber-reinforced resin molded body according to the present invention. [Diagram 3] FIG. 10 is a diagram for explaining another selection rule used in the fiber product selection step and the resin product selection step of the manufacturing method for a fiber-reinforced resin molding according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, a fiber-reinforced resin molded product according to the present invention and a method for producing the same will be described with reference to the accompanying drawings.

[0019] As shown in Figure 1, the manufacturing method of the present invention includes a textile product recovery process S1A, a subsequent textile product sorting process S2A, a resin product recovery process S1B, a subsequent resin product sorting process S2B, a mixing process S3 performed after the two sorting processes S2A and S2B, and a molding process S4 performed after the mixing process S3.

[0020] In the textile product recovery step S1A, textile products to be reused are recovered. Examples of textile products include used clothing and textile waste generated during the manufacturing process of clothing, but are not limited to these.

[0021] In the textile product sorting step S2A, textile products to be used as materials are sorted from the textile products collected in step S1A. In the present invention, as shown in FIG. 2, textile products are sorted based on the Munsell color wheel. For example, when a resin molded body having a color corresponding to 5YR is to be manufactured, textile products having a color included in a first color range defined by an interior angle of 85° are sorted. The first color range only needs to include a color corresponding to 5YR, and the color corresponding to 5YR does not necessarily have to be located in the center of the first color range. In addition, when a resin molded body having a color corresponding to 10PB is to be manufactured, textile products having a color included in a second color range defined by an interior angle of 85° are sorted. The second color range only needs to include a color corresponding to 10PB, and the color corresponding to 10PB does not necessarily have to be located in the center of the second color range.

[0022] The interior angle defining the color range was set at 85° based on knowledge gained from a survey conducted by the inventor in the past, namely, that the percentage of people who find a mixed fiber made by mixing any two or more cotton-like fibers of colors within 85° preferable is greater than the percentage of people who find a mixed fiber made by mixing any two or more cotton-like fibers of colors that are 85° or more apart preferable.

[0023] The sorting of textile products may be performed visually, or may be performed using a commercially available colorimeter (e.g., CM-2600d manufactured by Konica Minolta, Inc.) or a color sorter. When using a colorimeter or a color sorter, the output of the colorimeter or the color sorter may be input to the trained model to improve the accuracy of sorting.

[0024] In the resin product recovery process S1B, resin products to be reused are recovered. For example, the resin products may be caps of used PET bottles, but are not limited thereto. Note that there are caps that are mainly made of polypropylene (PP) and caps that are mainly made of polyethylene (PE).

[0025] In the resin product selection step S2B, resin products to be used as materials are selected from the resin products collected in step S1B. In the present invention, resin products are selected by the same method as in step S2A. That is, in step S2B, as shown in FIG. 2, resin products are selected based on the Munsell color wheel. For example, when a resin molded body having a color corresponding to 5YR is to be manufactured, a resin product having a color included in a first color range defined by an interior angle of 85° is selected. The first color range only needs to include a color corresponding to 5YR, and the color corresponding to 5YR does not necessarily have to be located in the center of the first color range. In addition, when a resin molded body having a color corresponding to 10PB is to be manufactured, a resin product having a color included in a second color range defined by an interior angle of 85° is selected. The second color range only needs to include a color corresponding to 10PB, and the color corresponding to 10PB does not necessarily have to be located in the center of the second color range.

[0026] Similar to sorting textile products, sorting of resin products can be done visually or using a commercially available colorimeter or color sorter (+ trained model).

[0027] In the mixing step S3, the fiber product and the resin product selected in steps S2A and S2B are mixed in a predetermined ratio.

[0028] Step S3 may include a step of pulverizing the selected textile product and resin product to an extent that they can pass through a mesh of a predetermined diameter (e.g., 2 mmφ). The textile product and resin product may be pulverized separately or together. Also, only one of the textile product and resin product may be pulverized.

[0029] Step S3 may also include pelletizing the mixture.

[0030] The ratio by weight of the mixed textile product and resin product is preferably textile product:resin product=20:80 to 40:60. The reason why the upper limit of the preferred textile product ratio is set to 40% by weight is that a ratio higher than this may cause problems in molding in the molding step S4. The reason why the lower limit of the preferred textile product ratio is set to 20% by weight will be explained later together with the experimental results.

[0031] In the molding step S4, the materials (the fiber product and the resin product) mixed in the step S3 are molded into a predetermined shape. Examples of the molding method include known molding methods such as injection molding and extrusion molding, but are not limited to these.

[0032] In this way, the manufacturing method according to the present invention uses a fiber product and a resin product that are selected according to a predetermined selection rule using color. Therefore, this manufacturing method can obtain an attractive fiber-reinforced resin molded product that is highly appealing (i.e., does not cause discomfort to the viewer) even though it does not include a step of bleaching at least one of the fiber product and the resin product before the mixing step S3, a step of bleaching the material before the molding step S4, and a step of dyeing the material before the molding step S4.

[0033] Next, a tensile test was performed on the test piece of the fiber-reinforced resin molding produced by the above-mentioned production method in accordance with JIS K7161 to measure the strength and elastic modulus. The results will be described.

[0034] In the first example, a test piece was prepared according to JIS K7139 using used clothing as the textile product and a cap (mainly made of PP) as the resin product. The ratio of the textile product was 10% by weight.

[0035] In the second to fourth examples, test pieces were prepared in the same manner as in the first example, except that the ratio of the textile product was 20% by weight, 30% by weight, and 40% by weight.

[0036] In the first comparative example, a test piece was made in accordance with JIS K7139 using only a cap (mainly made of PP) as a resin product.

[0037] In the fifth example, a test specimen was prepared according to JIS K7139 using used clothing as the textile product and a cap (mainly made of PE) as the resin product. The ratio of the textile product was 10% by weight.

[0038] In the sixth to eighth examples, test pieces were prepared in the same manner as in the fifth example, except that the ratio of the textile product was 20% by weight, 30% by weight, and 40% by weight.

[0039] In the second comparative example, a test piece was made in accordance with JIS K7139 using only a cap (mainly made of PE) as a resin product.

[0040] Table 1 summarizes the strength and elastic modulus of the test pieces according to the first to fourth examples and the first comparative example. This table shows that the strength and elastic modulus are improved by mixing a fiber product with a resin product mainly composed of PP. However, the test piece according to the first example, in which the ratio of the fiber product is 10% by weight, showed a strength improvement rate of only 1.95%. For this reason, the ratio of the fiber product is preferably 20% by weight or more. This table also suggests that the strength and elastic modulus are further improved by increasing the ratio of the fiber product to more than 40% by weight. However, care must be taken when the ratio of the fiber product exceeds 40% by weight, as described above, because this may cause moldability problems. [Table 1]

[0041] Table 2 summarizes the strength and elastic modulus of the test pieces according to the fifth to eighth examples and the second comparative example. This table shows that the strength and elastic modulus are improved by mixing a fiber product with a resin product mainly composed of PE. However, the test piece according to the fifth example, in which the ratio of the fiber product is 10% by weight, had a slightly reduced strength, although this may be due to measurement error. For this reason, the ratio of the fiber product is preferably 20% by weight or more. This table also suggests that the strength and elastic modulus are further improved by increasing the ratio of the fiber product to more than 40% by weight. However, care must be taken when the ratio of the fiber product exceeds 40% by weight, as described above, as this may cause moldability problems. [Table 2]

[0042] In this way, according to the manufacturing method of the present invention, a resin molded article reinforced with fibers can be obtained.

[0043] Although the fiber-reinforced resin molded product and the manufacturing method thereof according to the present invention have been described above, the configuration of the present invention is not limited to this.

[0044] For example, the interior angle of the Munsell hue circle that defines the color range may be 105° or any angle between 85 and 105°. This is based on the knowledge obtained from a questionnaire conducted by the present inventor in the past, that is, the percentage of people who find a mixed fiber made by mixing granular fibers of any two or more colors within 105° to be preferable is higher than the percentage of people who find a mixed fiber made by mixing granular fibers of any two or more colors that are 105° or more apart to be preferable.

[0045] In addition, the selection rules used in the selection steps S2A and S2B may stipulate that selection be performed using a color range defined by other known color indices such as the Japan Color Research Institute color scheme system, the NCS color system, the XYZ color system, CLab, RGB, HCV, etc.

[0046] In addition, the sorting rules used in the sorting steps S2A and S2B do not have to be the same. For example, as shown in FIG. 3, resin products may be sorted according to a third color range defined by an 85° interior angle of the Munsell hue circle, and textile products may be sorted according to a fourth color range defined by an 100° interior angle of the Munsell hue circle, i.e., a color range that includes the entire third color range. In other words, the sorting rules for textile products may be looser than the sorting rules for resin products. By adopting such a configuration, it becomes easier to secure a sufficient amount of textile products necessary to manufacture a resin molded body of a target color. This configuration is effective when the ratio of textile products is relatively small and the influence of the color of the resin products is strong. On the other hand, when the influence of the color of textile products is strong, the sorting rules for resin products can be looser than the sorting rules for textile products.

Claims

1. A method for producing a fiber-reinforced resin molding having a target color, A sorting process for sorting out textile products and resin products to be reused according to a predetermined sorting rule; a mixing step of mixing the materials selected in the selection step at a predetermined ratio; a molding step of molding the material mixed in the mixing step into a predetermined shape; Equipped with The sorting rules stipulate that the textile products and the resin products are to be sorted out so as to have colors within a color range including the target color. A manufacturing method comprising the steps of:

2. The color range is defined by the interior angles of the Munsell color wheel. The method according to claim 1 .

3. The interior angle is in the range of 85 to 105 degrees. The method according to claim 2 .

4. The resin product is a cap of a used PET bottle. The method according to any one of claims 1 to 3.

5. The ratio by weight of the materials mixed in the mixing step is the fiber product:the resin product=20:80 to 40:

60. The method according to any one of claims 1 to 3.

6. The method does not include a step of bleaching at least one of the fiber product and the resin product before the mixing step, and a step of bleaching the material before the molding step. The method according to any one of claims 1 to 3.

7. The method does not include a step of dyeing the material before the molding step. The method according to claim 6 .

8. A fiber-reinforced resin molded body having a target color, A sorting process for sorting out textile products and resin products to be reused according to a predetermined sorting rule; a mixing step of mixing the materials selected in the selection step at a predetermined ratio; a molding step of molding the material mixed in the mixing step into a predetermined shape; The method is produced by carrying out The sorting rules stipulate that the textile products and the resin products are to be sorted out so as to have colors within a color range including the target color. A fiber-reinforced resin molded body characterized by the above.

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