JPH0439010A - Molding method for composite molded object - Google Patents

Abstract

PURPOSE:To obtain an extensively homogeneous molded object, by a method wherein molten resin injected into a space between a stationary and movable molds is stemmed once by a stationary mold which is provided with a weir and when mold clamping is performed, the resin is brought into contact with the whole surface of a skin material by one effort. CONSTITUTION:A movable weir member 5, which is reciprocatable between a stemming position interrupting a passage of resin injected within a molding space from a gate 2b at close range from an opening of the gate 2b and a shunting position where the weir member 5 is withdrawn from a resin molding space and a part of the surface forms substantially a part of a mold surface, is provided in a stationary mold 2. After a skin material 8 is stuck to a movable mold 3 under a state where the movable mold 3 is separated sufficiently from the stationary mold 2 and a fixed quantity of molten resin 9 is injected under a state where the movable weir member 5 is projected to the front of an opening of a gate, the molten resin 9 is blocked by hitting against the tip part of the movable weir member 5, a speed and pressure are lowered remarkably and stuck to a resin molding surface of the stationary mold. With this construction, since contacting between molten resin 7 and the skin material 8 is started and completed in an extremely short time when mold clamping is performed, low pressure and uniform contacting is materialized extending over the whole surface and homogeneous composite molded product is obtained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to manufacturing a composite molded article made by pasting a desired skin material on the surface of a plastic base material in order to provide surface decoration or desired functionality. Regarding the method.

[Conventional technology]

Examples of these composite molded products include interior materials for automobiles, etc., and these composite molded products are usually made by adding highly decorative materials such as PvC leather or carpet to the base plastic molded product using an adhesive. It is made by pasting a skin material with However, these often require time and effort to process when pasting the skin material, which limits designs, has a high defect rate, and increases manufacturing costs.

Therefore, a composite molded product covered with a skin material is obtained by using a special stamping molding machine, applying a skin material inside the mold in advance, then injecting molten resin into the mold and closing the mold. A method has also been proposed.

However, in conventionally known stamping molding methods of this type, when injection of molten resin is started, part of the resin immediately comes into contact with the skin material, but on the other hand, the skin material is completely covered with resin. Since the contact time between the resin and the skin material differs in some parts, there are parts where the two come into contact at a high temperature and parts where they come into contact at a slightly lower temperature. Particularly when trying to obtain a large molded product, there is a drawback that a homogeneous product cannot be obtained, and to solve this problem, if the molten resin is placed evenly on the skin material, the time required will increase. occurs.

More specifically, in the vicinity of the gate, the injected high-temperature resin collides directly with the surface of the skin material under high pressure, and in the edge piece far from the gate, the resin is clamped. Because it comes into contact with the skin material at low temperature and low pressure, the thickness and density of the composite material may become uneven, and wrinkles and uneven gloss may occur on the surface, making it impossible to obtain a high-quality composite material. It is something.

In order to solve the above-mentioned problems, has a stamping molding machine been proposed, which injects and applies molten resin onto the surface of the skin material almost uniformly and then molds it? The problems of long cycles, limitations on the type of resin that can be used, and uneven temperature of the resin during molding have not been completely resolved.

Further, a dedicated stamping device is not only expensive, but also requires a considerable amount of time to obtain a molded product of good quality.

[The invention or the problem the invention is trying to solve]

The present invention has been made in order to solve the above problems, and its purpose is to make the above-mentioned large-sized stamping molding machine by using an inexpensive general-purpose injection molding machine without requiring a special stamping molding device. The purpose of the present invention is to provide a method for forming a composite body, and more specifically, when obtaining a large composite body such as the one described above, the molten resin is heated under the same conditions as possible and the skin material is removed in the shortest possible time. The object of the present invention is to provide a novel manufacturing method capable of forming a homogeneous molded body over the entire surface by bringing the molded body into contact with the molded body.

[Means to solve the problem]

The above purpose is to use a fixed mold equipped with a movable dam member to temporarily dam the molten resin injected into the space between the fixed and movable molds, make it adhere to the surface of the fixed mold, and quickly form the skin material. This is achieved by preventing the resin from coming into contact with the surface material and, when clamping the mold, bringing the resin into contact with the entire surface of the skin material at once to form a composite molded product.

More specifically, the above purpose is to provide a stationary mold that protrudes toward a movable mold and directs the passage of the resin injected from the gate to the opening of the gate, in order to obtain the composite molded product as described above. A movable weir member capable of reciprocating between a weir position in which it is blocked at a close distance from the molding space and a retracted position in which it exits the molding space and forms a part of the mold surface or substantially a part of the mold surface. This is achieved by using a fixed mold that is movable in and out, and by reciprocating the mold between the dam position and the retracted position to form a composite molded product.

This movable weir member is attached to perform linear movement, rotational movement, and combined movement relative to the fixed mold, and at one end of the movement, it dams the jet of resin injected from the gate, It is configured so that it sticks and stays on the resin molding surface of the fixed mold, and at the other end of the movement, is retracted to a position where it does not interfere with the closing of the mold or the resin molding.

Therefore, the movement path between the dam position and the retracted position is as follows:
It can be a straight movement path, a parallel movement path, a swing path, and any combination thereof.

Another object of the present invention is to form appropriate irregularities, grooves,
This can be achieved more reliably by providing protrusions that can be moved in and out, or by making the surface a swingable movable surface and performing molding while manipulating these as necessary.

[Effect]

With the above configuration, the molten resin can be uniformly brought into contact with the skin material at low pressure, evenly and within the shortest time, even if a general-purpose injection molding device is used without using a special stamping molding device, making it inexpensive. Moreover, it becomes possible to easily produce a high-quality composite molded body.

Furthermore, according to the present invention, it is possible to obtain a uniform composite even if a skin material that is relatively easily affected by heat is used, and it is also possible to create a composite with a special texture due to the influence of heat. becomes.

[Preferred Modes for Carrying Out the Invention] Hereinafter, preferred apparatuses and embodiments for carrying out the present invention will be specifically described with reference to the drawings.

1 to 4 are sectional views showing the state of each part of the mold at each step when obtaining a molded product using the mold according to the present invention, and FIG. 1 is a sectional view of the movable mold. Figure 2 is a cross-sectional view showing the state in which the movable dam member has been pulled away from the fixed mold and a skin material has been pasted on its surface. A sectional view showing the state in which the movable weir member is attached to and held on the resin molding surface, Fig. 3 is a sectional view showing the state in which the movable weir member is retracted to the retracted position, and Fig. 4 is a sectional view showing the state when the mold is closed and cooled. It is.

In the figure, 1 is an injection molding machine cylinder 2 is a fixed mold, 3 is a movable mold, 4 is a hydraulic cylinder 5 is a movable weir member,
6 is a link, 7 is an uneven member provided on the surface of the fixed mold 2,
8 is a skin material, and 9 is a molten resin.

The movable weir member 5 is held movably in a guide hole provided in the fixed mold 2 at a position close to the gate, and is connected to the rod of the hydraulic cylinder 4 via a link 6, as shown in FIG. and a dam position where the tip thereof protrudes into the resin molding space 2a toward the movable mold and crosses the path of the molten resin injected from the gate, as shown in FIG. As shown in Figures 4 and 4, the entire mold is retracted from the resin molding space and reciprocated between the retracted position where the tip surface substantially forms part of the fixed mold surface. It is configured to obtain.

When the movable dam member 5 is in the dam position, the molten resin injected from the gate is blocked by the movable dam member 5, and is adhered and held to the fertilizing surface of the fixed mold 2, so that the resin is not injected. There is no direct contact with the skin material.

The operation of opening and closing the mold is the same as in the normal injection molding process, and the first
As shown in the figure, with the movable mold 3 sufficiently separated from the fixed mold 2, a predetermined skin material 8 is attached to a predetermined part of the movable mold 3, and then the movable weir member 5 is attached to the gate opening. A predetermined amount of molten resin 9 is injected in a state where it protrudes to the front.

The injected molten resin 9 hits the tip of the movable weir member 5 and is blocked, its speed and pressure are significantly reduced, and it adheres to the resin molding surface of the fixed mold, forming a lump downward along the mold surface. It then slowly begins to flow down.

At this time, if a concavo-convex member 7 having a large number of protrusions is provided on the resin-attaching surface of the fixed mold 2, the flow rate of the molten resin will be further reduced, and the resin will stay in that part.

The concavo-convex member 7 may be fixed as in this embodiment, but it may also be attached so that it can tilt, or it may be constructed so that only the protrusions can go in and out from the resin molded surface.

In addition, in order to more reliably prevent the molten resin from leaving the fixed mold and hanging down toward the skin material, it is preferable that the main part of the resin molding surface of the fixed mold 2 is not vertical but is appropriately inclined. . For this reason, although it depends on the shape of the mold, the mold mating surfaces are usually inclined.

In addition, if it is not desirable to tilt the entire mold because the mold is large, at least this resin adhesive surface should be a single or zigzag slope, or it can be partially swung. It is recommended that the surface be kept movable.

After the injection of the molten resin 9 is completed, as shown in FIGS. 3 and 4, the movable weir member 5 which is pumping the molten resin
At the same time, the movable mold is moved forward to close the mold, cool for a predetermined period of time, and then open the mold to take out the product.

That is, the method of the present invention uses a fixed mold 2 having a gate for injecting molten resin into the resin molding space, and a movable mold 3 that is provided so as to be able to move toward and away from the fixed mold. -For forming a composite molded book, - in the above-mentioned fixed mold 2, a passage of the resin protruding into the resin molding space and injected into the molding space from the above-mentioned gate 2b is connected to the opening of the above-mentioned gate 2b. A movable dam that can reciprocate between a dam position where the dam is cut off at a close distance from the resin molding space and a retracted position where the dam exits from the resin molding space and a part of its surface substantially forms part of the mold surface. member 5 and a drive device 4.6 for reciprocating the movable dam member 5 between the dam position and the retracted position, and the fixed mold 2
is attached to a general-purpose injection molding machine together with the movable mold 3, and with the movable mold 3 sufficiently separated from the fixed mold 2, a desired skin material 8 is placed at a predetermined position on the movable mold 3. Steps to set.

fb) moving the movable dam member 5 to its dam position;

(c) A step of injecting the molten resin from the gate, stopping it with the movable dam member 5, making it stick to the resin molding surface of the fixed mold 2, and holding it.

(Move the movable weir member 5 to the retracted position and step b.

(e) A step of moving the movable mold 3 toward the fixed mold 2 and closing the mold.

(f) Cooling for a predetermined period of time in the closed state of the mold.

(Button) Separate the movable mold 3 from the fixed mold 2,
Step of taking out the product.

It consists of carrying out the following.

Therefore, each of the above steps is not necessarily performed sequentially over time; for example, step (bl) may be performed prior to step (a), and steps (a) and (c), and , steps (c) and (d) are preferably performed simultaneously in parallel, and step (a) may be completed at any time before step tel is completed.

Note that the configuration of the present invention is not limited to the above-mentioned embodiments, and can be applied to molding machines other than injection molding machines, such as extrusion molding machines and other various molding machines, and there are no limitations on the shape of the mold, etc. There are no restrictions, and it may be a fixed mold or core, a movable mold or a cavity, and the shape of the movable weir member may be a hinge type, a rotary type, a swing type, or a compound motion type. As an actuator for controlling its position or attitude, in addition to the links and hydraulic cylinders mentioned above, various types of cylinders, electromagnetic solenoids, direct drive systems using linear motors, etc., systems using screws and motors, etc. have been adopted. It is also recommended to link the opening and closing movements of the mold, and the arrangement and number of movable weir members can be changed as necessary. (Both are possible, and the present invention encompasses all embodiments and modifications that can be easily figured out by those skilled in the art from the above description within the scope of its purpose.

〔Effect of the invention〕

Since the present invention is constructed as described above, in accordance with the present invention, the contact between the molten resin and the skin material is started and completed within an extremely short period of time when the mold is closed, so that it is uniformly applied over the entire surface under low pressure. A uniform contact is achieved, which results in a homogeneous composite molded product.

[Brief explanation of drawings]

1 to 4 are cross-sectional views showing the state of each part of the mold in each step when obtaining a molded object using the mold according to the present invention, and FIG. 1 is a sectional view of the movable mold. Figure 2 is a cross-sectional view showing the state in which the movable dam member has been pulled away from the fixed mold and a skin material has been pasted on its surface. A sectional view showing the state in which the movable weir member is attached to and held on the resin molding surface, Fig. 3 is a sectional view showing the state in which the movable weir member is retracted to the retracted position, and Fig. 4 is a sectional view showing the state when the mold is closed and cooled. It is. 1...Injection molding machine 2...Fixed side mold 2a...Resin molding space 2b...Gate fixed mold Hydraulic cylinder Movable weir member Link Uneven member Skin material Molten resin

Claims (1)

[Claims] A fixed mold (2) having a gate (2b) for injecting molten resin into the resin molding space, and a movable mold (3) that is provided so as to be able to move toward and away from the fixed mold are used. In the method for forming a composite molded body consisting of a skin material and a resin layer, a resin is placed in the fixed mold (2), protruding into the resin molding space and injected into the molding space from the gate (2b). A dam position where the passage is blocked at a close distance from the opening of the gate (2b), and a retreat position where the passage is exited from the resin molding space and a part of the surface substantially forms part of the mold surface. a movable weir member (5) that can reciprocate between the weir positions, and a drive device (4, 6) that reciprocates the movable weir member (5) between the weir position and the retracted position, and injection molding. The method for producing the above-mentioned composite molded article, characterized in that the above-mentioned fixed mold and movable mold are mounted on a machine, and the method comprises the steps described in the following items (a) to (g). (a) A step of setting a desired skin material (8) at a predetermined position of the movable mold (3) with the movable mold (3) sufficiently separated from the fixed mold (2). (b) moving the movable dam member (5) to its dam position; (c) Inject the molten resin from the gate and inject the movable weir member (
Step 5) of damming and adhering to the resin molding surface of the fixed mold (2) and holding it. (d) A step of moving the movable weir member (5) to the retracted position. (e) A step of moving the movable mold (3) toward the fixed mold (2) and closing the mold. (f) Cooling for a predetermined period of time with the mold closed. (g) A step of separating the movable side mold (3) from the fixed side mold (2) and taking out the product.