JP7719039B2 - Model parts and manufacturing method of model parts - Google Patents

Description

The present invention relates to model parts and methods for manufacturing model parts.

When coloring the parts (also called components) of assembled models known as plastic models (registered trademarks), such as the faces of toys, each part is painted by hand, or spray painted using a mask with openings in the areas to be painted (see Patent Document 1). Automated painting using a coloring device equipped with multiple printing machines and conveyors has also been proposed (see Patent Document 2).

Publication number 3-34226 Japanese Patent Application Publication No. 8-47585

However, creating a gradation where the color gradually darkens requires skill, and it is difficult to achieve consistent quality. Furthermore, using a painting device poses the problem of additional capital investment and larger equipment. It has also been difficult to produce model parts with a consistently high-quality base layer that is visible from the outside.

The present invention therefore aims to provide a model component with a base layer of stable quality that can be seen from the outside, and a method for manufacturing such a component.

The invention of model parts
a first layer formed of a first material of a first color;
a second layer formed to cover at least a portion of the first layer, the second layer being made of a second material and having a second color;
the melting point of the first material is higher than the melting point of the second material;
The first layer is externally visible through the second layer.
The invention of model parts also
A model part that is combined with other model parts to form a doll toy,
a first layer formed of a first material of a first color;
a second layer formed to cover at least a portion of the first layer, the second layer being made of a second material of a second color; and
and
the melting point of the first material is higher than the melting point of the second material;
the first layer is visible from the outside through the second layer;
the first layer is connected to a first runner made of the first material for fixing the model part, and the second layer is connected to a second runner made of the second material for fixing the model part;
the first layer constitutes a body part of the doll toy;
The second layer constitutes the clothing of the doll toy.

The invention relates to a method for manufacturing a model part, and includes a first step of molding a first layer using a first material of a first color, and a second step of molding a second layer using a second material of a second color so as to cover at least a portion of the first layer, wherein in the second step, the second layer is molded before the first layer is cooled to room temperature, the melting point of the first material is higher than the melting point of the second material, and the first layer is visible from the outside through the second layer.
The invention also provides a method for manufacturing a model component that is combined with other model components to form a doll toy, the method comprising: a first step of molding a first layer using a first material of a first color; and a second step of molding a second layer using a semi-transparent second material of a second color so as to cover at least a part of the first layer, wherein in the second step, molding of the second layer is started at a predetermined temperature before the first layer is cooled to room temperature, the melting point of the first material is higher than the melting point of the second material, the first layer is visible from the outside through the second layer, and the first layer is formed using a molding material for fixing the model component. The first layer is connected to a first runner formed of a first material, and the second layer is connected to a second runner formed of the second material for fixing the model part, the first layer constituting a body part of the doll toy, and the second layer constituting a costume of the doll toy , and in the second step, the second layer is molded by pouring the second material into a cavity formed between the mold and a second surface opposite to the first surface, with the entire first surface of the first layer being directly supported by the mold, and in the model part, the second layer is formed on the second surface and not on the first surface .

The present invention provides a model component with a base layer of stable quality that can be seen from the outside, as well as a method for manufacturing the same.

1 is a flowchart illustrating an example of a method for manufacturing a model component according to an embodiment of the present invention. 1A to 1C are diagrams illustrating a molded product produced according to a method for manufacturing a model component according to an embodiment of the present invention. 1A and 1B are diagrams for explaining the structure of a model component corresponding to an embodiment of the present invention. 1A and 1B are diagrams for explaining a cross-sectional structure of a model part corresponding to an embodiment of the present invention.

Illustrative embodiments of the invention will be described below with reference to the drawings. Note that the same reference numerals in each drawing indicate the same elements. Furthermore, in each drawing, the up, down, left, and right directions on the paper surface will be used in the following description to refer to the up, down, left, and right directions of the parts (or components) in this embodiment. Note that in the embodiments described below, the present invention uses ABS (acrylonitrile-butadiene-styrene) resin, SBC (styrene-butadiene copolymer), and special styrene-based transparent resin as molding materials, but is not limited to these, and does not exclude the use of other materials (thermoplastic resins such as polyethylene, thermosetting resins, soft resins, metals, etc.).

First, a method for manufacturing a model part corresponding to an embodiment of the invention will be described according to the flowchart in Figure 1. In S101, primary molding is performed to form a primary molding layer that constitutes the skeleton of the model part. ABS can be used as the molding material (raw material) for the primary molding layer. Next, in S102, secondary molding is performed to form a secondary molding layer on the surface of the primary molding layer before the primary molding layer cools to room temperature. SBC can be used as the molding material for the secondary molding layer. The secondary molding layer will form the outer surface (skin) of the model part, and is formed so that the degree to which the color of the primary molding layer formed underneath shows through varies depending on the thickness of the secondary molding layer.

In the above process, the molding material that makes up the primary molding layer has an opaque color (e.g., flesh color, white, red, or other color, such as a solid color, metallic color, or pearlescent color) or a translucent (or even transparent) color (e.g., flesh color, white, red, or other color). The molding material for the secondary molding layer has a transparent or translucent color. For example, if the model part constitutes a doll's torso, the secondary molding layer that makes up the surface can be clear orange (transparent orange), while the primary molding layer can be white or flesh colored. In this case, making the secondary molding layer transparent or translucent makes it possible to express the appearance of wearing transparent or sheer clothing on the skin. The colors of the secondary molding layer and the primary molding layer can be the same or similar colors, or similar or contrasting colors, as long as the secondary molding layer is formed with a higher transparency. In this embodiment, the primary molding layer and secondary molding layer are formed from molding materials of different colors, and the secondary molding layer is formed from a clear or translucent material, allowing the primary molding layer of a different color underneath to be seen through, making it possible to create a gradation effect.

The molding material for each molding layer can be a common material to bond and integrate the primary and secondary molding layers. For example, PS, KPS, and GPPS have different properties, but they share the same polystyrene material. However, if the melting points of the materials are similar, when forming the secondary molding layer on top of the primary molding layer, the heat from the secondary molding layer and the frictional heat from injection molding can erode the primary molding layer, causing a rough surface. If the secondary molding layer is opaque, this is not a problem because the roughness of the primary molding layer, which serves as the base layer, cannot be seen from the outside. However, if the secondary molding layer is transparent or translucent, the surface of the primary molding layer can be seen through the secondary molding layer, causing a problem. On the other hand, if different materials (materials with different properties) are used for the primary and secondary molding layers, the bonding strength between the layers is weakened, resulting in the secondary molding layer easily peeling from the primary molding layer after molding.

In this embodiment, the primary molding layer is formed from ABS, and the secondary molding layer is formed from a different material, SBC. The melting point of ABS is 100 to 110°C, while the melting point of SBC is 80 to 100°C. Therefore, even if the primary molding layer is formed from ABS in the primary molding process and then the secondary molding layer is formed from SBC in the secondary molding process, the primary molding layer will not be eroded in the secondary molding process due to the difference in melting points. Therefore, roughness in the primary molding layer will not be visible through the secondary molding layer. Furthermore, in this embodiment, the primary molding layer is formed from ABS, and then the secondary molding layer is formed without cooling to room temperature, thereby maintaining the bonding strength between the layers. The temperature of the primary molding layer at the start of the secondary molding process may be a predetermined temperature higher than room temperature (e.g., 40 to 50°C, 30 to 60°C, or any range within that range) that allows it to be touched by hand.

The above-described method for manufacturing model parts, which consists of two molding steps, can be carried out using, for example, a multi-color molding machine. Each molding step uses a mold corresponding to that step. Specifically, molding material is poured into the mold's runner grooves and the molding spaces (cavities) used to mold each part to form a molded product, which is then removed from the mold. The primary molded product produced in the primary molding step is attached to the mold for the secondary molding step, and secondary molding is carried out. After primary molding, the primary molded product is attached to the mold for the secondary molding step without being cooled to room temperature. Because molding methods using multi-color molding machines are themselves well known, a detailed description will be omitted.

In addition, while the above describes the case where the primary molding layer is formed in a single molding process, the primary molding layer can be divided and primary molding carried out twice depending on the thickness of the primary molding layer to be formed and the color of the material. In this case, the molding process carried out will be in three stages. By dividing the primary molding layer into two parts, dents and distortions in the molding can be reduced, and a molded product with a uniform appearance can be produced.

Next, referring to Figure 2, the molding procedure from the primary molding layer to the secondary molding layer will be described in accordance with the molding method of Figure 1 corresponding to this embodiment. Figure 2 is a cross-sectional view of the mold and molded product during the molding process. Figures 2(A) and 2(B) correspond to the primary molding in S101. As shown in Figure 2(A), the mold (male mold 201 and female mold 202; the assignment of male and female molds may be reversed) has a cavity 203 corresponding to the primary molding layer to be molded, and the molding material ABS is poured into this cavity 203 via main and sub-runners (not shown) to form a part.

2(B), a molded product 204 is produced in primary molding using a male mold 201 and a female mold 202. The molded product 204 is composed of a main runner, a sub-runner, and a primary molding layer. The molded product 204 is made of ABS. The main runner is formed to surround the periphery of the part, and the part is fixed to the main runner by connecting to the main runner via the sub-runner. The main runner and sub-runner correspond to grooves for flowing molding material into the cavity 203 in the molding dies 201 and 202. In primary molding S101, molding material is flowed from the main runner groove through the sub-runner groove in the molding dies 201 and 202 into the cavity 203, filling the cavity, main runner groove, and sub-runner groove. After the molding material is cooled to a temperature that can be touched by hand (the above-mentioned predetermined temperature), the molded product 204 including the primary molding layer can be produced.

Next, in secondary molding in S102, a secondary molding layer is formed to cover the upper side of the primary molding layer, which is at a predetermined temperature. Figures 2(C) and 2(D) correspond to secondary molding in S102. As shown in Figure 2(C), a cavity 212 corresponding to the secondary molding layer to be formed in secondary molding is formed between the mold 211 and the molded product 204. The molding material, SBC, is then poured into this cavity 212 via main and auxiliary runners (not shown). This results in the formation of a molded product 213 including a secondary molding layer, as shown in Figure 2(D), in which the primary molding layer is at least partially covered with SBC. The molded product 213 is composed of the main runner, auxiliary runner, and secondary molding layer. In this embodiment, the secondary molding layer is formed by forming SBC on the upper surface of the ABS primary molding layer from the main runner through the auxiliary runner. At this time, the underside of the primary molding layer is supported by the molding die 202, so the position of the molded product 204 does not fluctuate, and it is possible to accurately form the molded product 213 so that the thickness of the secondary molding layer is the desired thickness.

In the secondary molding of S102, after the molded product 204 is fixed inside the molding dies 211 and 202, the molding material (SBC) is poured from the main runner groove through the sub-runner groove into the cavity 213, filling the cavity 213, the main runner groove, and the sub-runner groove. After the molding material has filled the cavity 213, the main runner groove, and the sub-runner groove, it is cooled, and the molded product 213 can be formed on the upper surface of the molded product 204.

Next, referring to Figure 3, an example of the structure of a model part manufactured according to the manufacturing method of Figures 1 and 2 will be described. Figure 3(A) shows an example of a model part 300 as part of the body of a doll toy, manufactured by a molding process corresponding to this embodiment. The outer surface 302 of the model part 300 is composed of a secondary molding layer, and the primary molding layer 301 covered by the secondary molding layer has a portion exposed to the outside as a connecting portion. The connecting portion functions as a connecting member for connecting to other parts.

Figure 3(B) is a diagram showing the model part 300 separated into multiple molding layers. Figure 3(B) shows a case where primary molding is performed in two stages. That is, the primary molding layer 301 is composed of the first molding layer 311 and the second molding layer 312, and the secondary molding layer 302 is composed of the third molding layer 313. The first molding layer 311 and the second molding layer 312 have different colors, but together they form the skeleton of the model part. Furthermore, the third molding layer 313 forms the outer skin of the model part. For simplicity's sake, the first molding layer 311 and the second molding layer 312 will be collectively referred to as the "skeleton," and the third molding layer 313 will be collectively referred to as the "outer skin."

In this embodiment, the outer skin is made of a transparent material so as to cover the skeleton, and has an uneven surface. The outer skin is a molded layer that forms the surface of the model component 200, and has a surface that corresponds to the desired outer shape of the model. Because the model component 200 is part of the torso of a doll toy, the unevenness of the torso is expressed by the surface shape of the outer skin.

When comparing the shapes of the outer surfaces of the skeletal portion and the outer skin portion, they are configured to include both similar and dissimilar portions. The thickness of the outer skin portion is maintained at a predetermined value for the similar portions. On the other hand, the dissimilar portions are formed to have a different thickness from the similar portions, and the color of the skeletal portion, which can be visually recognized from the outside through the outer skin portion, changes in accordance with the change in thickness. For example, if the outer skin portion is made of a translucent (e.g., clear orange) material and the skeletal portion is made of a white or flesh-colored material, the white or flesh color of the skeletal portion will be visible through the clear orange outer skin portion, or conversely, the orange will be more pronounced.

In this case, the thickness of the skin remains constant in areas with similar external shapes, so the color of the skeletal part visible through the translucent skin remains constant. However, as the skin becomes thicker, the orange color becomes stronger. Conversely, as the skin becomes thinner, the flesh color and white color become stronger. By adjusting the thickness of the skin in this way, it is possible to strengthen the flesh color, or conversely, strengthen the orange color. For example, the unevenness of the torso can be expressed by making the skin thinner in the convex parts of the skeleton to strengthen the flesh color, and by making the skin thicker in the concave parts to strengthen the orange color.

Next, the cross-sectional structure of the model component 300 corresponding to this embodiment will be described. Figure 4(A) is a diagram showing an example of how the thickness of the outer skin portion of the model component 300 shown in Figure 3(A) varies. As shown in the cross-sectional view of Figure 4(A), the outer skin portion that forms the outer surface of the model component 300 has thicknesses D1, D2, and D3, with thickness increasing in the order D1 > D2 > D3. In the component D1, the orange color of the outer skin portion appears darker, but as the outer skin portion becomes thinner as in D2 and D3, the orange color becomes weaker and instead the flesh color of the skeleton portion becomes stronger. The thicker the portion, the greater the degree to which the color of the outer skin portion blends with the color of the skeleton portion, resulting in a greater change in color when the model component 300 is viewed from the outside.

By varying the thickness of the outer skin part partially or entirely in this way, it is possible to vary the color tone of the model component 300 when viewed from the outside. In this case, in areas where the thickness of the outer skin part continuously increases, the degree to which the color of the outer skin part is mixed with the color of the skeleton part gradually increases. As a result, from the darkest area where the color of the skeleton part is visible through, the color gradually becomes lighter and changes to the color of the outer skin part itself, allowing the viewer to observe a gradation on the surface of the model component 300.

The appearance of the gradation can be changed by changing the thickness of the outer skin. For example, the way the color changes from dark to light will differ depending on whether the change in thickness is steep or gradual, allowing for different gradation expressions. The thickness can also be changed in the direction of decreasing, which allows for a change from light to dark colors.

Figure 4(A) illustrates an example in which a gradation effect is achieved by varying the thickness of the outer skin, but the present invention is not limited to the above embodiment, and the thickness of the outer skin may be constant, for example. Figure 4(B) is a diagram showing an example of the model component 300 in Figure 3(A) in which the thickness of the outer skin is uniform. As shown in the cross-sectional view of Figure 4(B), the thickness of the outer skin that constitutes the outer surface of the model component 300 is uniform.

In the above, we have described a case where the primary molding layer is made of ABS and the secondary molding layer is made of SBC, but the material combinations are not limited to this. For example, the primary molding layer may be made of ABS and the secondary molding layer of TPE (Thermoplastic elastomer: thermoplastic elastomer, particularly styrene-based thermoplastic elastomer). Alternatively, the primary molding layer may be made of KPS (reinforced polystyrene) and the secondary molding layer of TPE. Alternatively, the primary molding layer may be made of a first material with a higher melting point and the secondary molding layer of a second material with a lower melting point.

As described above, this embodiment makes it possible to provide a model component with a base layer of stable quality that can be seen from the outside, as well as a method for manufacturing the same.

Claims (9)

A method of manufacturing a model part that is combined with other model parts to form a doll toy,
a first step of forming a first layer using a first material of a first color;
a second step of molding a second layer using a second material of a translucent second color so as to cover at least a portion of the first layer;
Including,
In the second step, molding of the second layer is started at a predetermined temperature before the first layer is cooled to room temperature;
the melting point of the first material is higher than the melting point of the second material;
the first layer is visible from the outside through the second layer;
the first layer is connected to a first runner made of the first material for fixing the model part, and the second layer is connected to a second runner made of the second material for fixing the model part;
the first layer constitutes a body part of the doll toy;
the second layer constitutes a costume for the doll toy;
In the second step, the second layer is molded by pouring the second material into a cavity formed between the mold and a second surface opposite to the first surface, with the entire first surface of the first layer being directly supported by the mold;
In the model part, the second layer is formed on the second surface and not on the first surface.
Manufacturing method for model parts. 2. The method for manufacturing a model part according to claim 1, wherein the first material is an acrylonitrile butadiene styrene (ABS) resin and the second material is a styrene butadiene copolymer (SBC) resin, or the first material is an acrylonitrile butadiene styrene (ABS) resin and the second material is a thermoplastic elastomer (TPE) resin, or the first material is a reinforced polystyrene (KPS) resin and the second material is a thermoplastic elastomer (TPE) resin. The method for manufacturing a model component according to claim 1 or 2, wherein the predetermined temperature is within the range of 30 to 60 degrees. The method for manufacturing a model component according to claim 1 or 2, wherein the predetermined temperature is within the range of 40 to 50 degrees. A method for manufacturing a model component according to any one of claims 1 to 4, wherein the second layer includes portions of varying thickness. A method for manufacturing a model part according to any one of claims 1 to 5, characterized in that the transparency of the first color is lower than the transparency of the second color. A method for manufacturing a model part according to any one of claims 1 to 6, wherein the first color is opaque. A method for manufacturing a model part according to any one of claims 1 to 6, wherein the first color is translucent. the first step further comprises molding the first layer with the first material of a third color different from the first color and the second color;
9. A method for producing a model part according to any one of claims 1 to 8, wherein the first layer includes a portion formed of the first material of the third color.