JP2021159856A - Resin molding production method and resin molding - Google Patents

Abstract

To provide a resin molding production method and a resin molding capable of being helpful for solving ocean plastic refuse problem.SOLUTION: There is provided a production method of a resin molding 1, the method is for producing the resin molding 1 by thermal press of a plastic material including a thermoplastic resin by a press machine. The resin molding 1 of the invention is obtained by integrating plastic materials including the thermoplastic resin by a compression molding. As the plastic material including the thermoplastic resin, ocean plastic refuse can be used.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a resin molded product and a resin molded product.

In recent years, the so-called marine plastic waste problem, in which a large amount of plastic waste is washed ashore on the coast, has spread on a global scale, and various discussions have been held on efforts such as controlling the use and emission of plastic products.

Conventionally, as a method for producing a resin molded product that can help improve the marine plastic waste problem, a method for producing a resin molded product using plastic waste PET resin has been proposed (Patent Document 1).

In this manufacturing method, a crushing step of crushing a waste PET molded product to obtain a waste PET crushed product, a volatile component removing step of removing volatile components in the waste PET crushed product to obtain a raw material crushed product, and raw material crushing. A resin molded product is manufactured through a kneading step of kneading a product and an additive component to obtain a molding material and a molding step of molding the molding material into a molded product such as a tray or a tableware.

JP-A-2018-115289

In the above manufacturing method, a resin molded product is manufactured by injection molding. In injection molding, all the material needs to be melted because the material is injected from the cylinder nozzle. However, since marine plastic waste contains materials other than thermoplastic resin, such as thermosetting resin that does not melt, metal, shellfish, and sand, it can clog the molding machine or melt everything. Therefore, it is difficult to manufacture a resin molded product by injection molding.

The present invention has been made in view of such circumstances, and the problem to be solved is a resin capable of treating not only general waste plastics but also various foreign substances such as marine plastic waste. It is an object of the present invention to provide a molded product manufacturing method and a resin molded product.

[Resin molded product manufacturing method]
The method for producing a resin molded product of the present invention is a method for producing a resin molded product by putting a plastic material containing a thermoplastic resin into a mold and hot-pressing the mold. As the plastic material containing the thermoplastic resin, for example, marine plastic waste can be used. In the method for producing a resin molded product of the present invention, a plastic material can be crushed and a crushed piece obtained by crushing can be used.

In the method for producing a resin molded product of the present invention, plastic materials having different melting points (melting points) can be used. Further, in the method for producing a resin molded product of the present invention, the coating material can be integrally molded to produce a resin molded product whose surface is covered with the coating material.

In the method for producing a resin molded product of the present invention, an inorganic substance can be mixed to produce a resin molded product. Further, in the method for producing a resin molded product of the present invention, the plastic material or its crushed pieces can be washed and / and separated before being placed in the mold. In this case, the plastic material can be sorted by color or by material.

[Resin molded product]
The resin molded product of the present invention is a product in which a plastic material containing a thermoplastic resin is integrated by compression molding. In the resin molded product of the present invention, for example, marine plastic waste can be used as the plastic material containing the thermoplastic resin. In the resin molded product of the present invention, a crushed piece of the plastic material may be used as the plastic material containing the thermoplastic resin.

The resin molded product of the present invention may also use plastic materials having different melting points. Further, the coating layer may be integrally provided on the surface of the resin molded product of the present invention. The resin molded product of the present invention may be a mixture of inorganic substances.

Since the resin molded product manufacturing method and the resin molded product of the present invention manufacture the resin molded product by compression molding, there is no difficulty as in the case of manufacturing the resin molded product by injection molding, and various types such as marine plastic waste are used. Even if foreign matter is mixed, it can be processed.

The flowchart which shows an example of the resin molded article manufacturing method of this invention. (A) to (c) are explanatory views which show an example of the manufacturing process of the resin molded article provided with the coating layer. (A) and (b) are explanatory views which show an example of the resin molded article of this invention. (A) and (b) are explanatory views showing an example of a mold used for manufacturing a resin molded product. (A) and (b) are explanatory views showing another example of a mold used for manufacturing a resin molded product. Explanatory drawing in the case of manufacturing a resin molded product using a mold.

(Embodiment of Resin Molded Product Manufacturing Method)
An example of the embodiment of the method for producing a resin molded product of the present invention will be described with reference to the drawings. The method for producing a resin molded product of the present invention can be used as a method for producing a resin molded product 1 from various plastic materials containing a thermoplastic resin, but here, an example is obtained when the plastic material containing the thermoplastic resin is marine plastic waste. And.

As an example, the resin molded product manufacturing method shown in FIG. 1 is a method of manufacturing the resin molded product 1 through a crushing step S1, a cleaning step S2, a molding step S3, and a secondary processing step S4. The order of the crushing step S1 and the cleaning step S2 may be reversed. Further, a sorting step S5 for sorting marine plastic waste by color or type can be inserted before the crushing step S1 or before and after the cleaning step S2.

The crushing step S1 is a step of crushing marine plastic waste as a raw material to a desired size. In this step, marine plastic waste is crushed into a desired size (for example, about 10 to 50 mm). The crushed piece 2 obtained in this step becomes the main raw material of the resin molded product 1. The size of the crushed piece 2 may be larger or smaller than this. The size of the crushed piece 2 does not have to be constant, as long as it is a size suitable for processing. The crushing step S1 may be omitted depending on the size of the marine plastic waste.

The cleaning step S2 is a step of cleaning marine plastic waste as a raw material. In this step, the collected marine plastic waste is washed away with tap water, and then the marine plastic waste is washed with chlorine bleach. The washed marine plastic waste is dried in a drying oven or the like. Cleaning can be performed by other procedures.

The molding step S3 is a step of molding the resin molded product 1. In this step, the crushed piece 2 is put into a mold of a press machine (heat press machine) and hot pressed. It is preferable to apply a mold release agent to the upper plate 4 and the lower plate 5 of the mold before putting the crushed piece 2.

In the molding step S3, after pressing for a predetermined time, the mold is taken out from the press machine and the mold is cooled. After cooling, the upper and lower plates of the mold are opened, and the flat plate-shaped resin molded product 1 is taken out. Since burrs are generated on the resin molded product 1 by pressing, burrs are removed from the removed resin molded product 1. In addition, deposits and stains are removed from the surface of the resin molded product 1.

In the case of manufacturing the resin molded product 1 having the coating layer 3 on the surface, the coating material is placed on the lower plate 5 before the crushed piece 2 is placed on the lower plate 5, and the crushed piece 2 is placed on the lower plate 5. , Place the covering material on the crushed piece 2. By covering the upper plate 4 and heat-pressing in this state, it is possible to obtain a resin molded product 1 having both sides coated with a coating material (having a coating layer 3 on both sides). As shown in FIGS. 2 (a) to 2 (c), the covering material is deformed following the shape of the wall surface of the mold by the heat of the press and is joined at the top and bottom, so that the molded product can be covered without gaps.

As the coating material, for example, a thermoplastic transparent film such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), vinyl chloride (PVC), or polyethylene terephthalate (PET) can be used. The resin molded product 1 manufactured by the resin molded product manufacturing method of this embodiment contains different materials having different colors, sizes, materials, etc., and is excellent in designability. It is preferable to use an uncolored transparent film that does not impair (the color of the crushed piece 2 inside can be seen).

In molding the resin molded product 1, an inorganic substance may be mixed in addition to the crushed piece 2. As the inorganic substance, cloth such as glass woven cloth, various fibers (filamentous substances) such as fishing thread and fishing net, glass fiber and carbon fiber, sand, shellfish and the like can be used. By mixing these inorganic substances, the inorganic substances play a role of a binder, and the strength of the resin molded product 1 is improved.

In the past, although a large amount of fishing line and fishing nets were generated, they were rarely recycled and were often disposed of by incineration or landfill. By mixing it with the resin molded product 1 as in the present invention, it leads to the recycling of fishing lines and fishing nets that have been disposed of, and can help solve environmental problems.

In addition, instead of or together with the inorganic substance, an adhesive material such as EVA or SEBC can be mixed as a binder. As a result, it is possible to obtain the effect of improving the strength of the resin molded product 1 as in the case of mixing the inorganic substances.

In the molding step S3, when the upper plate 4 and the lower plate 5 have a desired three-dimensional shape, the shape of the product is formed by heat pressing. However, it may be advantageous to prepare a mere flat plate-shaped molded product in the molding step S3 and then perform the secondary molding in the secondary processing step S4. Specifically, it is easier to mix a plurality of types of materials to create a pattern with a clean composition by arranging the materials in a flat plate shape. In addition, in the case of a three-dimensional shape with depth, the mold becomes large and expensive. In this case, a desired three-dimensional product shape can be imparted by secondary processing.

The secondary processing step S4 is a step of processing a flat plate-shaped molded product into a desired shape. The secondary processing can be performed by vacuum forming, hand bending, or the like. Here, a case where a flat plate-shaped molded product is processed into a bowl shape will be described as an example.

In this step, two bowls are prepared, a flat molded product is placed in one bowl, and the mixture is heated to about 180 ° C. The other bowl is placed on the heated flat molded product, and pressure is applied from above. In that state, cool the molded product and remove it from the bowl when the shape is stable.

The secondary processing can also be performed by a method other than the above-mentioned method. The secondary processing step S4 may be performed as needed, and may be omitted if unnecessary. For example, when it is desired to obtain the flat resin molded product 1, it is sufficient to carry out the steps up to the molding step S3, so that the secondary processing step S4 can be omitted. When molding a flat plate-shaped resin molded product 1, a large mold block is not required and a thin mold is sufficient. Therefore, not only the mold manufacturing cost can be significantly reduced, but also the volume can be suppressed to a small size. , The heating time and cooling time of the mold can be shortened.

One of the features of the resin molded product manufacturing method of the present invention is that a material containing a mixture of thermosetting resin and inorganic substances can be molded. In injection molding, since the material is injected from the cylinder nozzle, it is necessary to melt all the materials, and if a material containing non-melting thermosetting resin or inorganic substances is used, the molding machine itself may be destroyed. be. On the other hand, in compression molding, such a problem does not occur because there is no injection step required for injection molding.

In addition, the method for producing a resin molded product of the present invention has another feature in that marine plastic waste containing a thermoplastic resin is molded by compression molding. In general, compression molding is a method used for molding a thermosetting resin, and is not usually used for molding a thermosetting resin. The reason is low productivity due to the need for a cooling process.

A cooling step is required because the thermoplastic resin does not harden unless it is sufficiently cooled and cannot be taken out from the mold. For this reason, when molding a thermoplastic resin by compression molding, it is necessary to add the steps of cooling the mold, taking out the molded product, inputting the next material, and raising the temperature of the mold to the normal compression molding process. be. When such a process is added, a waiting time for cooling is generated, which leads to a decrease in productivity.

Further, in injection molding, if different materials having different melting points are used, there may be a problem that the thermoplastic resin having a low melting point is decomposed while staying in the cylinder barrel. Further, dissimilar materials having low compatibility are difficult to join, and the surface of the molded product may be peeled off because it separates and flows at the time of injection.

On the other hand, in compression molding, the processing temperature is lower than that in injection molding because the material can be molded in a semi-molten state. Furthermore, even if a material with a low melting point is temporarily exposed to a high temperature, the temperature of the material is raised each time it is molded to melt the material, and then the material is cooled. Since it does not stay, even if different materials having different melting points are processed together, the risk of material decomposition is small.

As described above, the method for manufacturing a resin molded product of the present invention is a new resin molded product that cannot be obtained by injection molding by intentionally adopting compression molding, which is not normally adopted by those skilled in the art, for processing thermoplastic resins. It is valuable to be able to manufacture 1.

(Embodiment of Resin Molded Product)
An example of the embodiment of the resin molded product 1 of the present invention will be described with reference to FIGS. 3 (a) and 3 (b) to 5 (a) and 5 (b). As an example, the one shown in FIG. 3 (a) is a flat plate, and the one shown in FIG. 3 (b) is a bowl manufactured by processing (secondary processing) the flat plate.

The resin molded product 1 of this embodiment uses marine plastic waste as a main raw material, and crushed pieces 2 of marine plastic waste containing a thermoplastic resin are integrated by compression molding. Since various types of marine plastic waste used as the main raw material are mixed, the crushed pieces 2 often have different melting points.

In this embodiment, the crushed piece 2 is about 10 to 50 mm. The crushed piece 2 may be larger or smaller than this. Further, in this embodiment, a plurality of types of crushed pieces 2 having different colors are used, and the plurality of colors are configured to be visually recognizable in appearance. The resin molded product 1 of the present invention can also be configured by using only crushed pieces 2 of the same color. In this embodiment, the case where the crushed piece 2 of marine plastic waste is used is taken as an example, but it is not necessary to crush it when it enters the mold without crushing, and the uncrushed piece can be used as it is. ..

In this embodiment, the case where the resin molded product 1 is a flat plate and a bowl is taken as an example, but the resin molded product 1 of the present invention includes a trash can, a flowerpot, a flowerpot cover, a vase, a lamp shade, and the like other than the plate and the bowl. It may be.

The resin molded product 1 of this embodiment includes a coating layer 3 having a coating material on its surface. It is preferable to use a covering material that can follow the molded product and does not tear even when integrally molded.

As the covering material, it is preferable to use a thermoplastic transparent film such as the above-mentioned polycarbonate, polypropylene, or polyethylene terephthalate, and particularly, as the covering material, a non-colored transparent film in which the color of the crushed piece 2 inside can be seen.

The covering material protects the surface of the molded product that is easily peeled off by different materials that are difficult to join, and also has a protective function that prevents impurities derived from the crushed piece 2 from coming out, and a further function on the surface of the resin molded product 1. For example, it functions to impart antibacterial properties, scratch resistance, stain resistance, weather resistance, hygiene, and decorativeness. When dissimilar materials are integrally molded, the materials may peel off if the compatibility between the materials is low, but such peeling of the materials can be prevented by providing a covering material.

Further, since the covering material is compression-molded up and down by a hot press, the end face of the covering material tends to be weaker than the upper and lower surfaces. In this case, a resin molded product 1 having a high protection function and an excellent appearance design can be manufactured by inserting a member in which only the end face shape is molded in advance and heat-pressing. The method of inserting a member formed only in the end face shape and heat-pressing can be adopted even when the coating layer 3 is not provided. The coating layer 3 may be provided as needed, and may be omitted when it is not needed.

In the resin molded product 1 of the present invention, an inorganic substance or a binder can be mixed with the crushed piece 2. As the inorganic substance, a cloth such as the above-mentioned glass woven cloth, fibers such as fishing line, sand, shellfish and the like can be used, and as the binder, an adhesive material such as EVA and SEBC can be used. The effects of mixing inorganic substances and binders are as described above. The binder can be mixed in place of or with the inorganic material. A commercially available plastic raw material can be mixed with the resin molded product 1 of the present invention.

The resin molded product 1 of the present invention is characterized by having a design property that is not found in the conventional resin molded product 1. Since the materials (crushed pieces 2 and the like) do not mix with each other, the resin molded product 1 of the present invention can be made into an excellent aesthetic product by sprinkling the crushed pieces 2 and the like of various colors. In addition, since materials such as shells and metals that cannot be molded together in the past can be put together, the resin molded product 1 has an unprecedented design.

Further, when the coating layer 3 is provided on the surface, an arbitrary pattern or the like can be printed on the coating material, so that, for example, a resin molded product 1 having a company logo mark or the like can be manufactured. Further, by mixing a material that can be plated such as ABS and a material that cannot be plated, it is possible to create a pattern including a portion that is plated and a portion that is not plated in one product.

The plated pattern can also be used as a functional part such as electrical wiring. Further, in the resin molded product 1 of the present invention, unlike injection molding, the resin does not flow significantly, so that the pattern or characters of the material itself can be utilized as it is.

The resin molded product 1 of the present invention is, for example, a mold provided with an upper plate 4 and a lower plate 5 as shown in FIGS. 4 (a) and 4 (b), and an upper mold as shown in FIGS. 5 (a) and 5 (b). It can be molded using a mold provided with a middle plate 6 in addition to the plate 4 and the lower plate 5.

The mold shown in FIGS. 4A and 4B includes an upper plate 4 and a lower plate 5. The upper plate 4 and the lower plate 5 are provided with product-shaped recesses (hereinafter, the recesses of the upper plate 4 are referred to as "upper recesses" 4a and the recesses of the lower plate 5 are referred to as "lower recesses" 5a). When this mold is used, a material such as a crushed piece 2 is put in the lower recess 5a, and the upper plate 4 is covered from above. In this state, the die is placed in a hot press machine and hot pressed under predetermined conditions. After hot pressing, the die is taken out and the die is cooled. When the mold is sufficiently cooled, the mold is opened and the resin molded product 1 is taken out to obtain a flat plate-shaped resin molded product 1.

The mold shown in FIGS. 5A and 5B includes an upper plate 4, a lower plate 5, and a middle plate 6. The upper plate 4 and the lower plate 5 are flat plates, and the upper recess 4a and the lower recess 5a are not provided. On the other hand, the middle plate 6 arranged between the upper plate 4 and the lower plate 5 is formed with a through hole 6a having a desired shape (the shape of a clover in the illustrated example).

When this mold is used, a material such as a crushed piece 2 is put into the through hole 6a of the middle plate 6 placed on the lower plate 5, and the upper plate 4 is covered from above. In this state, the die is placed in a hot press machine and hot pressed under predetermined conditions. After hot pressing, the die is taken out and the die is cooled. When the mold is sufficiently cooled, the mold is opened and taken out to obtain a flat resin molded product 1.

Since the mold of FIG. 5 (a) is composed of three thin plates (upper plate 4, lower plate 5 and middle plate 6), it can be submerged as it is as shown in FIG. 5 (b). The cooling process can be simplified.

When the mold shown in FIG. 5A is used, the mold 7 as shown in FIG. 6 can be used instead of the middle plate 6. As the mold 7, for example, one made of resin can be used. In this case, the mold 7 and the material such as the crushed piece 2 are integrated by the hot press, and the end face of the product is protected by the mold 7. Even when the mold 7 is used, it is possible to produce a product having a design that is not found in the conventional resin molded product 1. It should be noted that the mold 7 may be made of a material other than resin.

The shapes of the through holes 6a of the middle plate 6 shown in FIGS. 5 (a) and 5 (b) and the shape of the mold 7 shown in FIG. 6 are examples, and the shapes of the through holes 6a and the mold 7 may be other than this. For example, it can have various shapes such as letters, numbers, symbols, figures, characters, and animals. The through hole 6a of the middle plate 6 can be formed by laser processing. The mold 7 can be formed by laser processing or resin molding. The resin molded product 1 obtained by using such a mold can be used as a key chain or the like.

The present invention is not limited to the structure and shape of each of the above-described embodiments, and various modifications and changes can be made without departing from the gist thereof.

The resin molded product manufacturing method and the resin molded product 1 of the present invention reuse marine plastic waste by mechanical recycling, and have industrial potential in that they help solve the problem of marine plastic waste.

1 Resin molded product 2 Crushed piece 3 Coating layer 4 Upper plate 4a Upper recess 5 Lower plate 5a Lower recess 6 Middle plate 6a Through hole 7 Formwork

Claims (14)

In the manufacturing method of resin molded products
Put the plastic material containing the thermoplastic resin in the mold and put it in the mold.
A resin molded product is manufactured by hot-pressing the die.
A method for manufacturing a resin molded product. In the method for producing a resin molded product according to claim 1,
Use marine plastic waste as a plastic material containing thermoplastic resin,
A method for manufacturing a resin molded product. In the method for manufacturing a resin molded product according to claim 1 or 2.
Crush plastic material containing thermoplastic resin,
Put the crushed piece obtained by the crushing into a mold.
A method for manufacturing a resin molded product. In the method for manufacturing a resin molded product according to any one of claims 1 to 3.
Use plastic materials with different melting points,
A method for manufacturing a resin molded product. In the method for manufacturing a resin molded product according to any one of claims 1 to 4.
A resin molded product whose surface is covered with a coating material is manufactured by integrally molding the coating material.
A method for manufacturing a resin molded product. In the method for manufacturing a resin molded product according to any one of claims 1 to 5.
Manufacture resin molded products by mixing inorganic substances,
A method for manufacturing a resin molded product. In the method for manufacturing a resin molded product according to any one of claims 1 to 6.
Cleaning and / and sorting the plastic material or its crushed pieces before placing the plastic material in the mold.
A method for manufacturing a resin molded product. In the method for manufacturing a resin molded product according to claim 7.
Sorting plastic materials by color or material,
A method for manufacturing a resin molded product. In resin molded products
Plastic materials containing thermoplastic resin are integrated by compression molding,
A resin molded product characterized by this. In the resin molded product according to claim 9,
The plastic material containing the thermoplastic resin is marine plastic waste,
A resin molded product characterized by this. In the resin molded product according to claim 9 or 10.
A crushed piece of plastic material was used as a plastic material containing a thermoplastic resin.
A resin molded product characterized by this. In the resin molded product according to any one of claims 9 to 11.
Plastic materials with different melting points were used,
A resin molded product characterized by this. In the resin molded product according to any one of claims 9 to 12.
A coating layer was provided on the surface,
A resin molded product characterized by this. In the resin molded product according to any one of claims 9 to 13.
A mixture of inorganic substances,
A resin molded product characterized by this.

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