TWI533993B - Metal mold for injection molding and method of manufacturing synthetics using the same - Google Patents

Description

Metal mold for injection molding and method for producing the same

The present invention relates to a mold and a method for producing a composite product in which a decorative layer is formed on a surface of a metal body and a resin portion is formed on a metal inner surface.

A molded article in which a metal material and a resin are integrated is used in various fields such as automobiles, household electrical products, mobile phones, and personal computers. A method of producing a synthetic product of a metal and a resin by using a resin on a metal material has been a method of injection molding using a resin or a method of applying a bonding layer to a metal surface to adhere a resin layer (see Patent Document 1).

Moreover, the decoration of the surface of the metal material is carried out by painting, sublimation transfer, laser printing, heat stamping, and stencil printing.

[Prior Art]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-144987

However, the number of processes for decorating the surface of the above-mentioned metal material is large, and when the resin portion is formed on the inner surface, it is necessary to perform a resin molding or resin injection molding in another process. Therefore, it takes a considerable amount of time and effort to decorate the surface of the metal material and form the resin portion on the inner surface.

Accordingly, an object of the present invention is to provide a metal mold for injection molding and a method for producing a composite product which can easily perform the decoration of the surface of the metal material and the resin portion of the inner surface molding.

The first characteristic configuration of the metal mold for injection molding of the present invention can be used for producing a synthetic product in which a resin portion is formed on the inner surface of the metal of the synthetic product, and the surface of the metal body is decorated with a decorative sheet while the resin portion is molded. The injection molding die includes a first mold having a first cavity surface on which the metal body is disposed, and a second mold having a second cavity surface formed along a surface of the metal body. Forming a cavity corresponding to the resin portion between the metal body and the first cavity surface by clamping the first die, and forming a gate facing the metal body in the first direction The cavity faces and the molten resin is ejected to the aforementioned cavity.

According to this configuration, in the state after the mold clamping, the molten resin is injected from the gate toward the inner surface of the metal, and the molten resin is injected into the cavity formed between the metal body and the surface of the first cavity, whereby the resin portion is formed on the metal. Inside the body. Further, when the decorative sheet is placed along the second cavity surface and the mold is clamped, the molten resin that is ejected from the metal body is pressed toward the second cavity surface, and the surface of the metal body is decorated with the decorative sheet. In this way, a synthetic product in which a resin is formed on the inner surface of the metal and the surface of the metal body is decorated while the resin portion is formed can be obtained.

According to a second aspect of the metal mold for injection molding of the present invention, the first mold includes a protruding portion that protrudes into the cavity, and the front end surface presses the inner surface of the metal body during the mold clamping.

According to this configuration, the portion in which the resin portion is formed on the inner surface of the metal is pressurized by the molten resin that is emitted, and the portion of the inner surface of the metal in which the resin portion is not formed is pressurized by the protruding portion. Therefore, even when the resin portion is partially formed on the inner surface of the metal body, the entire inner surface of the metal can be pressurized, and the surface of the metal body can be stably decorated.

According to a third aspect of the present invention, the metal mold for injection molding has a sliding mold, and the sliding mold is relatively movable in the mold clamping direction with respect to the first mold, and the tip end portion protrudes to the foregoing In the cavity, when the mold is clamped, the front end surface presses the inner surface of the metal body.

According to this configuration, when the sliding mold relatively moves relative to the first mold, and the front end portion of the sliding mold protrudes into the cavity, the front end surface of the sliding mold presses the inner surface of the metal body, and the portion of the sliding mold protruding in the cavity does not inject the molten resin. . As a result, the sliding mold has a portion in the inner surface of the metal in which the resin portion is not formed. In this way, it is possible to easily manufacture a synthetic product in which a resin portion is partially formed on the inner surface of the metal.

Further, by relatively moving the slide mold, the pressure at which the front end faces the inner surface of the metal body changes. Therefore, the pressure of the inner surface of the pressing metal can be easily adjusted.

According to a fourth aspect of the present invention, in the metal mold for injection molding, the first mold includes a peripheral abutting portion, and the peripheral abutting portion determines a position for arranging the metal body, and presses the metal body during mold clamping. The circumference of the face.

There may be a portion where the resin portion is not required in the peripheral portion of the inner surface of the metal body. In this case, since the peripheral abutting portion of the first metal mold presses the peripheral edge of the inner metal surface at the time of mold clamping, the resin portion is not formed at the peripheral portion of the inner metal surface pressed by the peripheral abutting portion. Further, the position of the metal body disposed in the first mold can be determined by the peripheral abutting portion.

The manufacturing method of the synthetic product of the present invention is characterized by a method for producing a synthetic product in which a resin portion is formed on the inner surface of the metal, and the surface of the metal body is decorated with a decorative sheet while the resin portion is molded. The method for producing a synthetic product is characterized in that a mold for injection molding having a first mold and a second mold is used, and the first mold and the second mold are formed by mold clamping to form a cavity corresponding to the resin portion. Further, the metal body is disposed on the first cavity surface of the first mold, and the process of the decorative film is disposed on the second cavity surface of the second mold having a shape along the surface of the metal body; Simultaneously pressing the inner surface of the metal surface, and exposing the molten resin toward the mold cavity toward the inner surface of the metal body, integrally forming the resin portion and the inner surface of the metal body, and simultaneously pressing the inner surface of the metal body The pressure and the heat and pressure of the molten resin fix the decorative sheet on the surface of the metal body.

According to this configuration, in the state after the mold clamping, the molten resin is emitted toward the inner surface of the metal body, and the molten resin is injected into the cavity formed between the metal body and the surface of the first cavity, whereby the resin portion is formed on the inner surface of the metal body. Further, in the decorative sheet disposed on the second cavity surface, the metal body is pressed toward the second cavity surface by the molten resin that is emitted, and the metal body is heated by the heat of the molten resin that is emitted, thereby promoting the surface of the metal body. Make decoration. In this way, it is possible to easily manufacture a synthetic product in which a resin portion is formed on the inner surface of the metal and the surface of the metal body is decorated by the decorative sheet while molding the resin portion.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]

Each of Figs. 1 to 3 is a view showing a molding forming process using the metal mold for injection molding of the present invention. Figure 4 is an enlarged view of the important part of Figure 2.

[metal body]

The metal body 20 has a flat plate shape and has a rising portion formed around it. On the surface of the metal body 20, a surface treatment is performed in advance so that the decorative layer can be easily formed, or a decorative layer can be attached in advance to easily follow the sheet. Further, on the inner surface of the metal body 20, a layer having a high adhesion property is formed by applying an adhesive layer to the inner surface of the metal body 20 so as to be easily fixed, or by chemical treatment. The surface treatment of the metal body 20 made of metal or the coating material on the surface and the inner surface is required to be selected in accordance with each combination of the decorative layer formed on the metal and the surface of the metal body 20 and the resin which is formed on the inner surface and molded into the resin portion. Suitable material.

[1st mold]

The first mold 1 is fixed to the fixed disk 11 and the first cavity surface 1A on which the metal body 20 is placed is formed. A recess 1a is formed in a peripheral portion of the first cavity surface 1A, and the recess 1a is a resin portion 30 for forming a convex shape on the inner surface of the metal body 20.

[2nd mold]

The second mold 2 is fixed to the movable platen 12, and has a second cavity face 2A having a shape along the surface of the metal body, and is clamped to the first die 1 and the slide die 3 to form a metal body and a first cavity. A cavity V corresponding to the resin portion 30 is formed between the faces 1A. Further, the second mold 2 is configured such that the decorative film F is disposed along the second cavity surface 2A when the mold is locked. After the metal body 20 is placed on the first cavity surface 1A of the first mold 1, the decorative film F is placed between the metal body 20 and the second mold 2. The decorative film F may be, for example, a roller-shaped long-sized film that is unfolded and disposed at the position, or may be formed by arranging and fitting the outer shape of the metal body 20. In the decorative film F is a transfer sheet and When the release sheet is formed, the transfer sheet becomes a decorative sheet 40 for decorating the surface of the metal body. The decorative film F itself may also be a decorative sheet 40 for decorating the surface of the metal body. Further, a heater H is provided inside the second mold 2. This heater H is a case where the heat of the molten metal on the surface of the metal body 20 is not sufficient, and the heat of the molten resin is not sufficient.

[sliding mold]

Inside the first cavity face 1A of the first die 1, there is a slide die 3 that is relatively movable in the mold clamping direction with respect to the first die 1. When the slide mold 3 is held at a position along the first cavity surface 1A, the resin portion 30 is entirely formed on the inner surface of the metal body 20 by the injected molten resin. When the front end portion 3a of the slide mold 3 protrudes into the cavity V and the front end surface 3A presses the inner surface of the metal body 20, the resin portion 30 is formed only on the peripheral portion of the inner surface of the metal body 20 by the injected molten resin.

[gate]

The first mold 1 has a gate 4 that emits molten resin. The gate 4 is formed on the first cavity face 1A so as to face the metal body 20 disposed on the first cavity face 1A. The molten resin that has been ejected is sent from the resin flow path 6 of the fixed disk 11 to the gate 4 through the resin flow path 5 of the first mold 1. Next, in a state after the mold clamping, the molten resin is injected from the gate 4 to the cavity V formed between the metal body 20 and the first cavity face 1A.

[Processing order of resin molding]

As shown in Fig. 1, the metal body 20 is placed at a predetermined position of the first mold 1 by using a robot or the like outside the drawing, and a decorative film is disposed between the second mold 2 and the metal body 20 disposed in the first mold 1. F. The metal body 20 disposed on the first cavity face 1A of the first die 1 is sucked and held by a suction hole (not shown) provided in the first die 1 or the slide die 3.

As shown in Fig. 2, when the second mold 2 is brought close to the first mold 1 and the mold is clamped, a cavity V is formed between the inner surface of the metal body 20 and the first cavity surface 1A. The molten resin is injected from the gate 4 provided in the first mold 1 to the formed cavity V. At this time, the inner surface of the metal body 230 is pressed toward the second mold 2 by the molten resin injected into the cavity V. Further, since the molten resin to be injected is a thermosetting resin or a thermoplastic resin and has a high temperature, the inner surface of the metal body 20 is heated while the resin is injected. Further, when the inner surface of the metal body 20 is heated to a high temperature, heat is also transmitted to the surface of the metal body 20 at a high temperature. As a result, the resin portion 30 is formed on the inner surface of the metal body 20 by the molten resin to be injected, and heat and pressure also act on the surface of the metal body 20, and the decorative sheet 40 is attached to the surface of the metal body 20. After the resin is cured, the mold is opened, and the synthetic product P is pushed out by a pusher (not shown) provided in the first mold 1 or the slide mold 3 to take out the synthetic product P (Fig. 3).

As shown in Fig. 3, the obtained synthetic product P is decorated with a decorative sheet on the surface of the metal body 20, and a resin portion 30 is formed on the inner surface thereof. In the injection molding die 10 of the present invention, the resin portion 30 is formed on the inner surface of the metal body 20, and the resin portion 30 is molded, and the surface of the metal body 20 can be decorated.

[Second Embodiment]

When the resin portion 30 is not integrally formed on the inner surface of the metal body 20, for example, when the resin portion 30 is molded only at the peripheral portion, as shown in Fig. 5, the front end portion of the slide mold 3 is protruded into the cavity V, when the mold is locked. The front end surface 3A is pressed toward the inner surface of the metal body 20. When the molten resin is injected in a state where the tip end portion 3a of the slide mold 3 is projected into the cavity V, the portion of the front end surface 3A where the inner surface of the metal body 20 is pressed is not injected with the molten resin. Therefore, the resin portion 30 is formed only on the peripheral portion of the metal body 20.

In this case, of course, the surface side of the inner surface of the metal body 20 which is not filled with the molten resin portion is not heated by the resin, and the surface temperature of the metal body 20 is maintained at a low temperature only at this portion, and there is a possibility that the decoration cannot be performed. Therefore, in this case, the heater H that is placed inside the second mold 2 may heat the hard-to-heat portion of the metal body 20. It is also possible to provide the heater H that heats the metal body 20 inside the slide mold 3.

[Other Embodiments]

(1) In the first embodiment, the injection molding die 10 in which the sliding die 3 is provided in the first die 1 is also formed when the resin portion 30 is entirely formed on the inner surface of the metal body 20. However, in this case, Next, the first mold 1 may not be provided with the slide mold 3. However, when the first mold 1 is equipped with the slide mold 3, the resin portion 30 on the inner surface of the metal body 20 can be selected by the position of the slide mold 3, and a plurality of synthetic products P can be easily manufactured.

(2) In the second embodiment, the slide mold 3 is relatively movable in the mold clamping direction with respect to the first mold 1, and the front end portion 3a is protruded from the cavity V, but the structure may be protruded to The front end portion 3a of the sliding mold 3 in the cavity V is regarded as a part of the first mold 1. That is, as shown in Fig. 5, the front end portion 3a of the slide mold 3 serves as a protruding portion of the first mold 1, and the inner surface of the metal body 20 is pressed against the end surface before the projection portion is formed during the mold clamping. When the inner surface of the metal body 20 is pressed by the slide mold 3 or the front end surface 3A of the protruding portion, when the molten resin is not allowed to flow between the inner surface of the metal body 20 and the front end surface 3A, the peripheral edge portion of the front end surface 3A can be pressed only. The inner surface of the metal body 20.

(3) As shown in Fig. 6, the inner surface of the metal body 20 may be pressed against the second mold 2 by a pressing mechanism 7 such as a spring provided in the slide mold 3. The pressing mechanism 7 not only imparts the pressure required for the decoration, but also absorbs the position of the inner surface of the metal body 20 and the front end portion 3a of the slide mold 3 during the mold clamping. That is, even if the front end portion 3a of the slide mold 3 protrudes beyond the inner surface position of the metal body 20 disposed on the first mold 1, the pressing mechanism 7 absorbs the inner surface of the metal body 20 and the front end portion of the slide mold 3 by the mold clamping. The position of 3a is offset. Therefore, it is easy to align the front end surface 3A of the sliding die 3 with the inner surface of the metal body 20. Further, by changing the spring force of the pressing mechanism 7, etc., the pressing force of the front end surface 3A of the sliding die 3 against the inner surface of the metal body 20 can be easily adjusted.

(4) As described in the second embodiment, even when the resin portion is formed only on the peripheral portion of the inner surface of the metal body 20, a portion where the resin portion 30 is not required may be present in the portion of the inner peripheral edge portion 20A of the metal body 20. In this case, as shown in FIG. 7, a convex peripheral abutting portion 1b which is in close contact with the inner surface of the metal body 20 in the mold clamping state is provided at a necessary portion of the peripheral edge portion of the cavity surface 1A of the first metal mold 1. As a result, as shown in FIG. 8, the resin portion 30 is not formed in the portion of the inner peripheral portion of the inner surface of the metal body 20 of the synthetic product P that does not require the resin portion 30. Further, when a plurality of convex peripheral abutting portions 1b are provided in a portion corresponding to the peripheral edge of the metal body 20, the positioning of the metal body 20 in the first cavity surface is facilitated by the peripheral abutting portion 1b. Further, it is necessary to strongly press the peripheral abutting portion 1b that has not been molded to abut against the inner surface of the metal body 20 during the mold clamping.

(5) The peripheral portion of the inner surface of the metal body 20 is partially not formed with the resin portion 30 by providing the peripheral abutting portion 1b on the first cavity surface 1A, but the cavity portion V of the peripheral portion of the metal body 20 is provided. When the peripheral abutting portion 1b is partitioned, the resin injection gate 4 corresponding to the number of the cavities V is required in the first metal mold 1. Therefore, as shown in Fig. 7, it is preferable that the peripheral abutting portion 1b of the first metal mold 1 is provided with a communication portion 1c that communicates with the cavity V adjacent to the peripheral abutment portion 1b while being injected to the other side. Resin. When the peripheral abutting portion 1b is provided to leave the communicating portion 1c, the amount of the resin injection gate 4 can be reduced, and the structure of the injection molding die 10 can be simplified.

(6) The metal body 20 may be a surface in which the resin portion is filled with a resin in a hole or a recess provided in a part of the metal body 20. In the case of such a metal body 20, the decorative layer can be continuously transferred to the metal portion and the resin portion. In this case, an LED or a liquid crystal may be provided in the resin portion, and a display portion may be provided.

[Industrial availability]

In the various fields such as automobiles, household electrical products, mobile phones, and personal computers, the present invention can be widely used in the production of metal bodies in the synthetic products containing the metals, regardless of the interior or exterior products. A synthetic product in which a resin layer is formed on the inner surface of the decorative layer.

1‧‧‧1st mould

2‧‧‧2nd mould

3‧‧‧Sliding mold

4‧‧‧ gate

5‧‧‧Resin flow path

6‧‧‧Resin flow path

7‧‧‧Pushing mechanism

10‧‧‧ Injection molding metal mold

11‧‧‧ Fixed disk

12‧‧‧ movable plate

20‧‧‧Metal body

30‧‧‧Resin Department

40‧‧‧Decorative film

1A‧‧‧1st cavity face

1a‧‧‧ recess

1b‧‧‧Weekly Abutment

1c‧‧‧Connecting Department

20A‧‧‧The Peripheral Department

2A‧‧‧2nd cavity face

3a. . . Front end

3A. . . Front end face

F. . . Decorative film

H. . . Heater

P. . . Synthetic product

V. . . Cavity

Fig. 1 is a view showing a surface of a mold for injection molding according to the first embodiment.

Fig. 2 is a view showing a forming process of the injection molding die according to the first embodiment.

Fig. 3 is a view showing a forming process of the injection molding die according to the first embodiment.

Fig. 4 is an enlarged view showing a molding process using the metal mold for injection molding of the first embodiment.

Fig. 5 is a view showing a molding process using the metal mold for injection molding of the second embodiment.

Fig. 6 is a view showing a forming process of a mold for injection molding according to another embodiment.

Fig. 7 is a view showing a drawing of a metal mold for injection molding according to another embodiment.

Fig. 8 is a view showing the inner surface shape of the formed metal forming ornament.

1‧‧‧1st mould

2‧‧‧2nd mould

3‧‧‧Sliding mold

3A‧‧‧ front face

4‧‧‧ gate

5‧‧‧Resin flow path

10‧‧‧ Injection molding metal mold

11‧‧‧ Fixed disk

12‧‧‧ movable plate

20‧‧‧Metal body

30‧‧‧Resin Department

H‧‧‧heater

V‧‧‧ cavity

Claims (5)

A metal mold for injection molding, which can be used for producing a synthetic product, wherein a resin portion is formed on a metal inner surface of the synthetic product, and the surface of the metal body is decorated with a decorative sheet while the resin portion is molded, and the metal mold for injection molding is characterized. The first mold has a first cavity surface on which the metal body is disposed, and the second mold has a second cavity surface formed along a surface of the metal body, and is locked with the first die. a mold, wherein a cavity corresponding to the resin portion is formed between the metal body and the first cavity surface; and a gate formed on the first cavity face facing the metal body and melted The resin is ejected to the aforementioned cavity. The injection molding die according to the first aspect of the invention, wherein the first mold includes a protruding portion that protrudes into the cavity, and the front end surface presses the inside of the metal body during mold clamping. surface. The injection molding metal mold according to the first aspect of the invention, further comprising a sliding mold, wherein the sliding mold is relatively movable in the mold clamping direction with respect to the first mold, and the front end portion The protrusion protrudes into the cavity, and when the mold is clamped, the front end surface presses the inner surface of the metal body. The injection molding die according to any one of the first to third aspect, wherein the first mold includes a peripheral abutting portion, and the peripheral abutting portion determines a position at which the metal body is disposed. At the same time, after the mold clamping, the circumference of the inner surface of the metal body is pressed. A method for producing a synthetic product, wherein a resin portion is formed on a surface of a metal body, and the surface of the metal body is decorated with a decorative sheet while the resin portion is molded, and the method for producing the composite product is characterized in that the first mold is used. And a mold for injection molding of the second mold, wherein the first mold and the second mold form a cavity corresponding to the resin portion by mold clamping, and the metal is placed on the first cavity surface of the first mold a process of arranging the decorative sheet on a second cavity surface having a shape along a surface of the metal body of the second mold; and a process of pressing the inner surface of the metal while clamping the mold to form the cavity; The molten resin is injected toward the cavity, and the resin portion is integrally molded with the inner surface of the metal, and the pressure of the inner surface of the metal and the heat and pressure of the molten resin are used to The decorative sheet is fixed to the surface of the aforementioned metal body.