Manufacturing method of molding material using cloth fiber

Abstract

To provide a manufacturing method of a molding material using cloth fibers, which can easily prepare a molding material in which cloth fibers are uniformly mixed.SOLUTION: A manufacturing method of a molding material using cloth fibers comprises: a first pulverizing step (step 1-1) for pulverizing a cloth into a cotton-like material; a compression step (step 1-2) for compressing cloth fibers pulverized by the first pulverization step into a compressed body; a second pulverizing step (step 1-3) for pulverizing the compressed body solidified by the compression step into a powder-like material; and a molding step (step 1-4) for molding a material obtained by heating and melting a cloth powder pulverized in the second pulverizing step mixed with a thermoplastic synthetic resin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a molding material using cloth fibers such as cotton. [Background technology]

[0002] Conventionally, molding materials have been developed and used that are made by mixing synthetic resin with powders derived from plants such as wheat bran, bamboo, and coffee grounds, or powders of minerals such as zeolite and talc, and then heating, melting, and molding the mixture (see, for example, Patent Documents 1 and 2).

[0003] This type of molding material allows the mixing ratio of synthetic resin in the molding material to be reduced, and also allows for effective use of organic waste materials such as bran, bamboo, and coffee grounds, making it environmentally friendly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-224665 A [Patent Document 2] JP 2016-23282 A Summary of the Invention [Problem to be solved by the invention]

[0005] The powders of various waste materials to be mixed into the molding material must be crushed into small pieces in order to thoroughly mix the powders of the various waste materials into the molten synthetic resin.

[0006] However, when trying to create a molding material by mixing cloth fibers, such as discarded clothing, the following problems arose.

[0007] That is, when cloth fibers such as cotton cloth are crushed, the fibers expand like cotton and are light in weight (low density), so when trying to mix them with molten synthetic resin, they are difficult to mix with the synthetic resin in the first place, and even if they are mixed, they are difficult to distribute evenly throughout the synthetic resin, so there is a risk that they will harden in some places, or conversely, there will be places where they are only sparsely present. For this reason, it has been difficult to create a molding material by mixing cloth fibers with synthetic resin.

[0008] The present invention has been made in consideration of the above-mentioned points, and its object is to provide a manufacturing method for molding materials using cloth fibers, which can easily create molding materials in which cloth fibers are uniformly mixed. [Means for solving the problem]

[0009] The method for producing a molded material using cloth fibers according to the present invention includes a first crushing step of crushing cloth into a cotton-like material, a compression step of compressing and solidifying the cloth fibers crushed in the first crushing step into a compressed body, a second crushing step of crushing the compressed body solidified in the compression step into a powdered material, and a step of mixing the cloth powder crushed in the second crushing step with a synthetic resin, heating and melting the mixture, and molding the mixture. 1. A molding process; A third crushing step of crushing the molding material molded by the first molding step into a powder form, and a second molding step of heating, melting, and molding the powder of the molding material crushed by the third crushing step; The present invention is characterized in that it has the following features. According to the present invention, the cloth fibers that become only cotton-like in the first crushing process are first solidified into a compressed body in the compression process, and the solidified and densified compressed body is crushed again in the second crushing process, so that cloth that is difficult to crush into powder can be powderized, and it is thereby possible to mix the cloth powder evenly into synthetic resin and mold it. Furthermore, depending on the type of cloth and the state of crushing in the first and second crushing steps, the mixed state of the synthetic resin and the cloth powder in the molding material molded in the first molding step may be insufficient (uneven). If the mixed state is insufficient, for example, the shape of the molding material molded in the first molding step may not be the desired shape. In such a case, as in the present invention, the molding material is further crushed in a third crushing step. Since the cloth powder is fixed in the synthetic resin by the first molding step, if this molding material is crushed, the cloth can be crushed further finely together with the synthetic resin. This allows the powder of cloth fibers crushed more finely to be mixed uniformly in the molding material molded in the subsequent second molding step, and the molding material can be more reliably molded into the desired shape.

[0010] In addition to the above features, the present invention further comprises the 1. The blending ratio of the powdered cloth in the molding step is 10 to 30 mass %, and the blending ratio of the synthetic resin is 70 to 90 mass %. The reason why the blending ratio of the cloth powder is set to 30 mass% or less is that the density (unit: kg / m3 ) is quite small (low), so it tends to float up from the synthetic resin powder. This phenomenon becomes particularly noticeable when the blending ratio of the cloth powder exceeds 30 mass%, 1. It becomes difficult to mix and mold the cloth powder and synthetic resin evenly during the molding process. For this reason, the blending ratio of cloth powder is set to 30 mass% or less. On the other hand, the blending ratio of cloth powder is set to 10 mass% or more because if the blending ratio of cloth powder is too low, the effect of effectively utilizing the cloth is reduced. In other words, the blending ratio of the present invention is specific to cloth powder with very low density. Effect of the Invention

[0012] According to the present invention, a molding material in which fabric fibers are uniformly mixed can be easily produced. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a process diagram of a method for producing a molding material. [Diagram 2] FIG. 2 is an explanatory diagram of a specific method for producing a molding material. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing an agitation mixer 50 and an extruder 60. [Figure 4] FIG. 2 is a process diagram of a method for producing a molding material. [Diagram 5] FIG. 2 is an explanatory diagram of a specific method for producing a molding material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. [First embodiment] Fig. 1 is a process diagram of a manufacturing method of a molded material according to a first embodiment of the present invention. As shown in the figure, the manufacturing method of a molded material according to the first embodiment includes a first crushing step (step 1-1) of crushing a cloth into a cotton-like shape, a compression step (step 1-2) of compressing the cloth fibers crushed in the first crushing step into a plate-like compressed body, a second crushing step (step 1-3) of crushing the compressed body solidified in the compression step into a powder shape, and a first molding step (hereinafter referred to as "molding step" in this embodiment) (step 1-4) of mixing the cloth powder crushed in the second crushing step with a thermoplastic synthetic resin, heating and melting the resin to mold it.

[0015] The materials (fibers, textile fibers) used for the fabric include a variety of natural fibers, such as cotton, linen, and silk, as well as synthetic fibers (nylon, acrylic, polyester, etc.).

[0016] In the first crushing process in step 1-1, the cloth is crushed finely using a crusher, but due to the characteristics of the cloth fibers, the crushed cloth becomes finely cut fibers, each fiber intertwined in a complex manner, and becomes a fluffy, light, and large mass of cotton-like material. Even if this mass of cotton-like material is crushed further in a crusher, it tends to remain cotton-like.

[0017] In the compression process of step 1-2, for example, a press is used to place an upper mold with a flat lower surface on a lower mold having a concave storage section for storing the cotton-like cloth fibers, and the upper mold is inserted into the storage section of the lower mold to press and compress the cotton-like cloth fibers that have been stored in the storage section beforehand. This compresses the cotton-like cloth fibers and hardens them into a flat-plate-like compressed body. Instead of using a press, the cotton-like cloth fibers may be passed between a pair of rollers to pressurize them into a flat-plate-like compressed body.

[0018] In the second crushing step of step 1-3, the plate-shaped compressed body that has been hardened and made denser by the compression step is crushed again. At this time, the compressed body made of the cloth fibers is crushed into powder. The cloth fibers are turned into powder because the plate-shaped compressed body that has been made hard by increasing the density of the cloth fibers is crushed. This results in a cloth powder with a relatively high density.

[0019] In the molding process of steps 1-4, the powder of the cloth pulverized in the second crushing process and the powder of a thermoplastic synthetic resin are mixed, for example, using a stirring mixer, and then fed into, for example, an extruder, where the mixture is heated, melted, and kneaded. After that, the mixture is drawn out, for example, into a thin rod shape and cut into short pieces with a cutter, thereby obtaining a molding material molded into pellets.

[0020] As described above, the cloth fibers that become only cotton-like in the first crushing process are first solidified into a plate shape in the compression process, and this solidified and densified plate shape is then crushed again in the second crushing process, so that cloth that is difficult to crush into powder can be made into a powder, and a molding material in which cloth fibers are evenly mixed into synthetic resin can be created.

[0021] (First Example) Fig. 2 is an explanatory diagram of a specific method for producing a molding material according to a first example of the first embodiment. As shown in Fig. 2(a), first, a cloth 10 to be mixed into the molding material is prepared. Cotton cloth is used as the cloth 10 used here. Next, as shown in Fig. 2(b), the cloth 10 is fed into a crusher 20 and crushed (the first crushing step, step 1-1). As a result, the cloth 10 is crushed into a fibrous form, resulting in a cotton-like material 25 as shown in Fig. 2(c).

[0022] Next, as shown in Fig. 2(d), the cotton-like material 25 is compressed by a press or other pressure molding machine 30, thereby forming a flat compressed body (hereinafter referred to as "plate") 35 as shown in Fig. 2(e) (the compression process, step 1-2 above). Next, as shown in Fig. 2(f), the plate 35 is fed into a crusher 40 and crushed (the second crushing process, step 1-3 above). This results in a cloth fiber powder 45 with a relatively high density as shown in Fig. 2(g).

[0023] Next, the cloth fiber powder 45 (10-30% by mass) and separately prepared polypropylene pellets (or powder) 47 (70-90% by mass) are charged into a stirring mixer 50 and stirred and mixed (see FIG. 2(h)). This stirred mixture is charged into an extruder 60 shown in FIG. 2(i) and heated, melted and kneaded, and then, for example, drawn into a thin rod shape and cut into short pieces with a cutter to obtain a pellet-shaped molding material 65 shown in FIG. 2(j) (the above molding process, step 1-4).

[0024] FIG. 3 is a schematic cross-sectional view showing the stirring mixer 50 and the extruder 60. As shown in the figure, the stirring mixer 50 puts the cloth fiber powder 45 and the polypropylene pellets (or powder) 47 into a hopper 51 and stirs and mixes them with a stirring member 53. Next, the mixture mixed in the stirring mixer 50 is introduced into the extruder 60, and a screw 63 provided with a helical protrusion 62 is rotated in a cylinder 61 while being heated by a heater 64, thereby melting the polypropylene in the mixture, and uniformly kneading the cloth fiber powder 45 into the molten polypropylene. Then, a rod-shaped molding material is discharged from a nozzle (not shown) provided near the end of the extrusion side of the extruder 60, cut into short lengths with a cutter (not shown), and hardened to obtain a pellet-shaped molding material. Through the above steps, the pellet-shaped molding material 65 according to the first embodiment is completed.

[0025] Here, the mixing ratio of the cloth powder 45 is set to 30 mass % or less because the density (unit: kg / m) of the cloth powder 45 is small when the cloth powder 45 and the polypropylene pellets (or powder) 47 are kneaded.3 ) is considerably smaller than that of polypropylene, the cloth powder 45 is likely to float upward from the polypropylene pellets (or powder) 47 during mixing in the mixing machine 50, and this phenomenon becomes more pronounced when the mixing ratio of the cloth powder 45 exceeds 30% by mass, which makes it difficult to mix the two materials well, and therefore makes it difficult to mix and mold the cloth powder 45 and polypropylene 47 properly when the mixture is fed from the mixing machine 50 to the extruder 60 for molding. The mixing ratio of the cloth powder 45 is set to 10% by mass or more because if the mixing ratio of the cloth powder 45 is too low, the effect of effectively utilizing the cloth is reduced. In other words, this mixing ratio is specific to the cloth powder 45, which has a very low density compared to synthetic resins.

[0026] In the next process, the molding material (pellets) 65 manufactured as described above is fed, for example, into an injection molding machine, heated and melted, and then injected into the cavity of a mold connected to the injection molding machine. It is then cooled and solidified, becoming a molded item formed into the shape (final shape) of various products.

[0027] Second Embodiment Fig. 4 is a process diagram of a manufacturing method of a molding material according to a second embodiment of the present invention. As shown in the figure, the manufacturing method of a molding material according to the second embodiment includes a first crushing step (step 2-1) of crushing a cloth into a cotton-like shape, a compression step (step 2-2) of compressing the cloth fibers crushed in the first crushing step into a plate-like compressed body, a second crushing step (step 2-3) of crushing the plate-like compressed body solidified in the compression step into a powder shape, a first molding step (step 2-4) of mixing the powder of the cloth crushed in the second crushing step with a thermoplastic synthetic resin, heating and melting the mixture, and molding the mixture, a third crushing step (step 2-5) of crushing the molding material molded in the first molding step into a powder shape, and a second molding step (step 2-6) of heating and melting the powder of the molding material crushed in the third crushing step and molding the mixture.

[0028] The first pulverization step (step 2-1), compression step (step 2-2), second pulverization step (step 2-3), and first molding step (step 2-4) in this second embodiment are the same as the first pulverization step (step 1-1), compression step (step 1-2), second pulverization step (step 1-3), and molding step (step 1-4) in the first embodiment, so detailed explanations are omitted. On the other hand, the second embodiment differs from the first embodiment in that a third pulverization step (step 2-5) and a second molding step (step 2-6) are provided, so these steps will be mainly explained below.

[0029] In the molding step (steps 1-4) in the first embodiment, the shape of the molding material formed into pellets was not the desired shape, and the molding material was sometimes deformed. The cause of this may be that the powdering of the cloth fibers in the first and second crushing steps was not performed sufficiently due to the material of the cloth fibers or the weaving method of the cloth, and the mixture of the synthetic resin and cloth powder in the molding material became insufficient.

[0030] Therefore, in the case of this embodiment, after the first molding step (step 2-4) corresponding to the molding step (step 1-4) in the first embodiment, the molding material molded in the first molding step is again pulverized into powder in a third crushing step (step 2-5), and the molding material is again molded in a second molding step (step 2-6). Since the cloth powder is fixed in the synthetic resin in the first molding step (step 2-4), by crushing this molding material, the cloth powder can be crushed even finer and more uniformly together with the synthetic resin.

[0031] In the second molding step of step 2-6, for example, the powder consisting of the synthetic resin and cloth powder crushed in the third crushing step (step 2-5) is fed into an extruder, for example, and is heated, melted, and kneaded by the extruder to obtain a molding material molded into, for example, a pellet shape. Since each powder crushed in the third crushing step is in a state where the cloth powder is solidified with the synthetic resin, that is, since there is no need to knead the single cloth powder during the second molding step, a molding material in which the cloth powder is evenly dispersed in the synthetic resin can be easily obtained.

[0032] Furthermore, the powder to be fed into the extruder in this second molding step may be prepared by adding a new synthetic resin powder alone to the powder consisting of the synthetic resin and cloth powder crushed in the third crushing step, and stirring and mixing these with a stirring mixer, etc. In this case, too, since each powder crushed in the third crushing step is in a state in which the cloth powder is solidified with the synthetic resin, even if a single synthetic resin powder is added to this powder and stirred and mixed, there is no need to knead the single cloth powder during the second molding step, and a molding material in which the cloth powder is evenly dispersed in the synthetic resin can be easily obtained.

[0033] As described above, in this embodiment, the powder of more finely ground cloth fibers can be more uniformly mixed into the molding material formed by the second molding step, and the molding material can be more easily molded into the desired shape.

[0034] (Second Example) Fig. 5 is an explanatory diagram of a specific method for producing a molded material according to a second example of the second embodiment. In the second example, similar to the contents explained in Figs. 2(a) to (j) above, first prepare a cloth (cotton cloth) 10 to be mixed into the molded material (Fig. 5(a)), put the cloth 10 into a crusher 20 and crush it (Fig. 5(b)) to make a cotton-like material 25 (Fig. 5(c)), then solidify the cotton-like material 25 with a pressure molding machine 30 such as a press machine (Fig. 5(d)) to mold it into a flat plate-like plate 35 with high density (Fig. 5(e)), and then press the plate. The body 35 is pulverized by a pulverizer 40 (FIG. 5(f)) to obtain a cloth fiber powder 45 (FIG. 5(g)). Next, the cloth fiber powder 45 (10-30% by mass) and separately prepared polypropylene powder 47 (70-90% by mass) are charged into an agitator mixer 50 and agitated and mixed (FIG. 5(h)). This agitated mixture is heated, melted and kneaded by an extruder 60 (FIG. 5(i)), and then molded into pellets to obtain a molding material 65 (FIG. 5(j)).

[0035] Next, the formed material 65 (FIG. 5(j)) obtained as described above is again fed into the crusher 70 shown in FIG. 5(k) and crushed (the third crushing step, step 2-5 above). As a result, the formed material 65 is crushed into fine powder 75 as shown in FIG. 5(l).

[0036] Next, the powder 75 is fed into an extruder 80 (FIG. 5(m)), heated, melted, and kneaded, and then, for example, drawn into a thin rod shape and cut into short pieces with a cutter, thereby obtaining a pellet-shaped molding material 85 shown in FIG. 5(n) (the second molding process, step 2-6 above).

[0037] As another embodiment, a separately prepared polypropylene powder may be mixed with the powder 75 obtained by carrying out the third pulverization step (step 2-5) shown in Fig. 5(k) when carrying out the second molding step (step 2-6) by the extruder 80 shown in Fig. 5(m). In this case, the separately prepared polypropylene powder and the powder 75 shown in Fig. 5(l) are charged into the stirring mixer 50 similar to that shown in Fig. 2(h) and stirred and mixed, and the stirred mixture is charged into the extruder 80 shown in Fig. 5(m) to obtain a molding material 85 molded into a pellet shape as shown in Fig. 5(n).

[0038] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the technical ideas described in the claims, specification, and drawings. Any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical ideas of the present invention as long as it achieves the functions and effects of the present invention. For example, in the above embodiment, one type of cloth (cotton cloth) is used as the cloth, but a mixture of multiple types of cloth may be used. In the above example, the shape of the compressed body compressed in the compression process is a plate shape, but it may be various shapes other than a plate shape. In addition, the molding material to be molded does not need to be pellet-shaped, and may be molded into various other shapes, or in some cases directly into the shape of the final product. In addition, the crushers 20, 40, and 70 may be the same crusher or different crushers. Similarly, the extruders 60 and 80 may be the same extruder or different extruders.

[0039] In addition, the embodiments described above and shown in each drawing can be combined with each other as long as there is no contradiction in the purpose, configuration, etc. In addition, even a part of the description in the above description and the description in each drawing can be an independent embodiment, and the embodiment of the present invention is not limited to one embodiment that combines the description in the above description and each drawing. [Explanation of symbols]

[0040] 10 cloth 20 Crusher 25 Cottony body 30 Pressure molding machine 35 Plate 40 Crusher 45 powder 47 powder 50 Stirring mixer 60 Extruder 65 Molding material 70 Crusher 75 Powder 80 Extruder 85 Molding material

Claims

1. A first crushing step of crushing the cloth into a cotton-like material; a compression step of compressing and solidifying the fabric fibers pulverized in the first pulverization step into a compressed body; A second crushing step of crushing the compressed body solidified by the compressing step into a powder form; A first molding step of mixing the powder of the cloth pulverized in the second crushing step with a synthetic resin, heating and melting the resin, and molding the resin; A third crushing step of crushing the molding material molded in the first molding step into a powder form; A second molding step of heating, melting, and molding the powder of the molding material pulverized in the third pulverization step; A method for producing a molding material using cloth fibers, comprising:

2. A method for producing a molding using the fabric fiber according to claim 1, A method for manufacturing a molding material using cloth fibers, characterized in that the blending ratio of the cloth powder in the first molding step is 10 to 30 mass %, and the blending ratio of the synthetic resin is 70 to 90 mass %.

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