JPS60201930A - Manufacture of resin molding - Google Patents

Abstract

PURPOSE:To mold even a product having a complicated shape easily by a method wherein a heated mold is set in a powder resin holding tank and turned, a molten resin layer is formed and set to a cooling tank and an expanded resin is injected into a mold cavity in the molding of a sheet, etc. for a car. CONSTITUTION:A mold 6 previously heated by a fluidized bed is set to a holding tank 10, the inside thereof holds powder resin 9 and turned around a shaft 13 to form a molten resin layer on the molding surface 6a of the mold. The mold 6 is set to a cooling tank 10, and cooled by cooling water from showers 15 and a skin 21 is formed while a mold cavity 8 set to a cooling tank 14 is covered with a movable die 16 to which a core material 20 is fitted or is not fitted, a resin as foams 22 is injected into the cavity 8 by an injector 17 and solidified, and terminal treatment is executed. Accordingly, processes up to unifying from skin molding are executed through a series of processes, no bubbles, etc. are included in the surface of a product, and even a complicated product can be molded easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing resin molded products such as interior parts such as automobile console boxes, door panels, packet seats, and headrests, or motorcycle seats.For example, foam materials have recently been used as vehicle seats. A resin molded product is used in which the surface of the foam is covered with a resin skin, and the back surface of the foam is supported by a core material. The most common method for manufacturing such resin molded products is to prepare the skin, foam in the shape of the product, and core material in advance, attach the foam and core material, and then attach the foam and core material to the skin. This method involves wrapping the foam. However, when using this method, after cutting the skin to match the product shape, the ends of the skin must be folded in and sewn or glued to the core material, etc., which requires many manual steps and is extremely inefficient. Therefore, there is a disadvantage that wrinkles are likely to occur at the folded part of the epidermis. In addition, a resin sheet such as vinyl chloride is vacuum-formed to form a skin that matches the shape of the product, and this skin is attached to a foam mold to make the foam -J.
There is also a way to solidify one person. However, when this method is used, when vacuum forming the resin sheet into a predetermined skin shape, the sheet stretches, making the grain unclear or creating thinner parts in some areas. Furthermore, when attaching the skin to the foam mold, there is a disadvantage that wrinkles and folding marks remain in the rounded portion.

Furthermore, after filling the plastic sol into the heated mold,
After a certain period of time, the plastic sol is discharged from the mold to form a gel-like plastic layer of a predetermined thickness on the inner surface of the mold, which is then covered with the skin, and then a foam is injected into the mold and solidified. A method using so-called slush molding is also considered.

However, when using this method, air is trapped when the plastic in a sol state is attached to the inner surface of the mold, and when it is heated later, the air tends to remain, resulting in a product that contains air bubbles inside. In this method, the process of filling a heated mold with plastic sol and discharging it is repeated, so the shape of the mold is limited to a relatively simple one, and a large number of old molds must be prepared.
The equipment also makes a loud noise.

The present invention has been made in order to improve the drawbacks of the conventional methods described above, and its purpose is to manufacture a resin molded product that integrates a skin, a foam, and a core material, from the molding of the skin to the molding of the skin. To provide a method for producing a resin molded product, which can be completed in a series of steps up to integration, does not contain air bubbles in the skin of the obtained product, and can be easily molded even if the product has a complex shape. .

In order to achieve the first and first objectives, the present invention involves placing a mold heated in advance in a fluidized bed in a holding tank containing powdered resin.
This holding tank is rotated to form a molten resin layer on the molding surface of the mold, and then the mold is set in a cooling tank to use the molten resin layer as a skin, and the mold cavity set in the cooling tank is used as a core material. The gist is that the mold is covered with a movable mold with a core attached or a movable mold with no core attached, and in this state, a resin that will become a foam is injected into the cavity and solidified, and then terminal treatment is performed.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of the mold heating device "i" used in the present invention.
Inside (1), a filter (2) made of sintered stainless steel fibers is installed in the horizontal direction, and this filter (2) controls the inside of the heating tank (1) into the lower chamber (Sl) and the lower chamber (S1).
2). The lower chamber (S1) is filled with particles (3), such as alumina particles, that serve as a heating medium, and a heater (4) is provided, while the lower chamber (S2
) An air introduction pipe (5) is attached to the side wall of the chamber (S2) to supply compressed air into the lower chamber (S2). The compressed air supplied into the lower chamber (S2) enters the upper chamber (Sl) via the filter (2), and the particles are heated to 350°C to 400°C by the heater (4). (
3)... is made to flow and a fluidized bed (
7). Then, a mold (
6) Soak. Here, when immersing the mold (6), a support piece (l) protruding from the inside of the heating tank (1)
a), while locking the flange part of the mold (6) to (Ia), with the inner molding surface (6a) of the mold (6) facing upward;
The molding surface (6a) is heated in such a manner that the particles (3) do not adhere to the molding surface (6a). In addition, particles (3) scattered on the molding surface (6a)
)... to prevent 4=J from attaching to the mold cavity (
8) may be covered with M(9). After the mold (6) is heated to about 240°C to 250°C in the first step, the mold (6) is removed from the fluidized bed (7),
Proceeding to step 22 shown in Figure 2. That is, in the second step, a holding tank (10) holding powdered resin (8) such as vinyl chloride in a fluid state is prepared. Then, set the heated mold (8) in the upper opening of this holding tank (10) so that the molding surface faces downward.The inside of the holding tank (1G) is covered with a filter (11). It is divided into a partial chamber (S3) and a lower chamber (S4), and an air introduction pipe (12) is connected to the lower chamber (S4) to supply compressed air into the lower chamber (S4). The compressed air supplied into (S4) enters the -1 part chamber (S3) via the filter (11), and makes the powdered resin (9)... in a fluid state. In addition, the holding tank (10) has a horizontal rotation axis (13)
It rotates in a vertical plane about a rotation axis (13). Holding 40 (10) facing the mold (6
) while clamping the holding tank (lO) at 180°, for example.
Rotate to invert the mold (6) and holding 40 (10). Then, the powdered resin (9) in the holding tank (10)...
・Transfers into the mold (6) and heats up to high temperature (24G"0~250°)
Powdered resin (9) in contact with the molding surface (6a) of C)...
is melted to form a molten resin layer on the molding surface (6a). Here, the molten resin layer is formed so as to be gradually piled up starting from a portion close to the surface of the molding surface (8a), so that no air is contained inside. The mold (6) with the molten resin layer formed on the molding surface (6a) is placed in the holding tank (10).
), the mold (8) is set to 1 (14) for cooling as shown in FIG. 3, and the third step is performed. That is, the cooling tank (10) is opened at the top, and the mold (6) is set in the cooling tank (14) by locking the flange of the mold (6) in this opening. A cooling shower (15) is installed inside the tank.Instead of this shower (15), a wind cooling nozzle may be installed.
4) A movable mold (18) that can be moved up and down is placed above the
An injection device (17) for injecting molten resin is fixed to this movable mold (16), and this injection device (17)
) and an injection hole (18) connected to the suction vent (18).
) is installed.

In the third step, a core material (20) made of ABS resin or the like is previously adsorbed onto the mold surface of the movable mold (16) through the ventilation holes (18). In addition, this core material (20)
has a hole (20a) at a location that coincides with the injection hole (18).
The mold (16) is placed in the cooling tank (14).
) After setting the movable mold (!6), lower the movable mold (!6) and place the core material (2
0) to close the cavity (8) of the mold (6), and then
Foam raw materials such as urethane resin are injected from the injection device (17) into the cavity (
8) Charge Jd within. First, the mold (6) is cooled to around 60°C by the shower (15) of the cooling tank (14), so the molten resin layer formed on the molding surface (6a) of the mold (6) It cools and solidifies to become the skin (21), and the urethane resin filled in the cavity (8) also solidifies to become the foam (22), forming the skin (21), foam (22), and core material ( 20) are integrated.

After that, in the fourth step, as shown in FIG. 4, the integrated skin (21), foam (22) and core material (
20) is taken out, and an adhesive (23) is applied to the inner surface of the skin (21) protruding from the end of the core material (20). After this, as shown in FIG. 5, the pressing device (24)
Fold the end of the skin (21) inward to form the core material (20)
The resin molded product (25) is obtained by pressing the resin molded product (25) and bonding with an adhesive (23). In the illustrated example, the end portion of the skin (21) is treated with the core material (
20), but it may also be fixed with a stapler or the like. 6 to 8 show another embodiment in which the third and subsequent steps are different. In this embodiment, as shown in FIG. (20) is not adsorbed, but directly on the mold surface of the movable mold (16),
The cavity of the mold (6) set in the cooling tank (14) (
8) to form an intermediate molded body (26) that integrates the atomized body (22) and the skin (21), and then, as shown in FIG. 6), and the core material (20) prepared separately is poured into the foam (
22) Paste it on the back side, and then fold back the ends of the skin (2, 1) that protrude from the ends of the core material (20) and tighten them to the core material (20), as shown in Figure 8. Then, the desired resin molded product (25) is obtained.

In addition, although the illustrated example shows an example in which the mold is heated using a heated fluidized bed, there are other methods such as heating the mold with a nichrome wire heater, heating the mold itself with electricity as a resistor, etc. , various heating methods are possible.

As explained above, according to the present invention, a bolt can be produced in which the steps from forming the skin to integrating the skin, foam, and core material are performed in a series of steps. The skin itself can be molded without manual work such as cutting, and compared to vacuum forming or slush molding, it can be of high quality without wrinkles or bubbles, etc. Demonstrates the effect of

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing steps 1 and 8 of the mold forming step of the method of the present invention, Fig. 2 is a sectional view showing the skin forming step, which is the second step, and Fig. 3 is A cross-sectional view showing the third step of the same, which is the step of integrating the skin, foam, and core material, and FIG.
A cross-sectional view showing the step of taking out the integrated molded product from the mold, FIG. 5 is a cross-sectional view showing the end treatment step, which is the fifth step, and FIGS. 6 to 8 are from the third step, respectively. It is a sectional view showing another example of the fifth lower part. In addition, in the drawing (
1) is a heating tank, (3) is a particle serving as a heating medium, (6) is a mold, (6a) is a molding surface, (7) is a fluidized bed, (8) is a mold cavity, and (9) is a mold cavity. Powder resin, (10) is a powder resin holding tank, (14) is a cooling tank, (16) is a movable type, (
17) is an injection device, (18) is an injection hole, (20) is a core material, (21) is a skin, (22) is a foam, and (25) is a resin molded product. Patent applicant Honda Motor Co., Ltd. Agent Patent attorney 2 1) Production Department Patent attorney Kuni Ohashi Production volume Patent attorney Yu Koyama Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) Upper end open I of a holding tank that holds powdered resin in a fluid state
Set the heated mold with the molding surface facing downward, and in this state rotate the holding tank to bring the powdered resin into contact with the molding surface to form a molten resin layer on the molding surface. The mold with the molten resin layer formed thereon is set in a cooling tank to use the molten resin layer as a skin, and the mold cavity set in the cooling tank is covered with a movable mold with a core material attached to the mold surface. The resin that will become the foam is injected into the cavity through the injection hole formed in the injection hole and the hole formed in the core material to integrate the skin, the foam, and the core material, and then the resin protrudes from the end of the core material. A method for producing a resin molded product, characterized in that the end of the skin is folded inward and subjected to end treatment such as adhesion to a core material or wearing. (2) Set the heated mold between ends 1-1 of the holding tank that holds the powdered resin in a fluid state with the molding surface facing downward, and in this state rotate the holding tank to release the powdered resin. A molten resin layer is formed on the molding surface by contacting the molding surface, and the mold with this molten resin layer is set in a cooling tank to use the molten resin layer as a skin, and the mold set in the cooling tank is The mold cavity is covered with a movable mold, and the resin that will become the foam is injected into the mold cavity through the injection hole formed in the movable mold to create a molded body in which the foam and the skin are integrated. is removed from the mold, and a separately prepared core material is pasted on the back of the foam. After this, the outer skin end protruding from the end of the core material is folded inward and glued or fastened to the core material. 1. A method for producing a resin molded product, characterized in that the end treatment is carried out.