JP2001088166A - Lamination molding method and lamination molding - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To obtain a laminated molded product having a deep and high-grade appearance by forming a transparent or substantially transparent resin layer in appearance. SOLUTION: After filling a first resin between a back surface of a skin material and a cavity surface of a mold facing the back surface of the skin material, a surface of the skin material and a metal facing the surface of the skin material are filled. A cavity is formed between the mold and the cavity surface, and the cavity is filled with a second resin to form a transparent or substantially transparent resin layer on the surface of the skin material to form a deep layer. To form a high quality laminated molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamination molding method for integrally molding a skin material and a molten resin, and a lamination molded product. The present invention relates to a high-quality bonded molded article and a method of bonding and forming the same.

[0002]

2. Description of the Related Art Conventionally, as a method of improving the appearance and feel of a molded product to increase the added value of the molded product, a skin material cut into a predetermined shape is inserted between a pair of opened molds. After the mold is closed, a lamination molding method of filling a molten resin as a core material into a mold and integrally molding the skin material and the resin of the core material is performed.

[0003] The skin material used in the lamination molding method has a pattern printed thereon as a decoration for enhancing the added value on the surface (sometimes referred to as the front side) of the skin material which forms the appearance after molding. In recent years, a transparent or almost transparent resin layer (referred to as a clear resin layer) has been formed on the surface of the skin material in order to form a deep and luxurious laminated molded product. Bonding is often performed using a skin material on which (sometimes) is formed.

[0004] Such a skin material having a clear resin layer on the surface is generally obtained by printing a pattern or a character on a film (also referred to as a base film) as a base, and printing the pattern or characters on the printed surface. It is manufactured by coating a clear resin layer. The clear resin layer has a function of protecting a pattern or the like printed on the skin material and improving abrasion resistance and weather resistance. The appearance with a certain can be formed.

[0005]

However, when the thickness of the clear resin layer is increased to increase the gloss of the skin material used in the conventional laminating method, the thickness of the skin material increases. There is a problem that the winding length per weight is shortened and handling is reduced,
In addition, when the thickness of the clear resin layer is increased, the thickness of the skin material is increased, the shapeability of the skin material is deteriorated, and wrinkles are easily generated when the skin material is sandwiched in a mold.

[0006] In the conventional lamination molding method, since it can only be used with a skin material that can be formed without causing wrinkles or tears when sandwiched in a mold, the thickness of the clear resin layer can be reduced or The type of the resin in the clear resin layer had to be soft.

However, if the thickness of the clear resin layer is reduced, the appearance of the molded article does not become deep and the sense of quality is lost, and if the type of resin of the clear resin layer is made soft, the hardness of the clear resin layer becomes low. When shaping the skin material in the mold, the coated clear resin layer may be damaged by rubbing or scratching with the mold, or the surface of the finished molded product may be damaged. This has the drawback that it tends to stick and is inferior in durability.

Further, at the time of laminating, when disposing of the remaining skin material (cut portion or the like) obtained by cutting the skin material into a predetermined shape, the type of the resin of the clear resin layer to be coated with the base film of the skin material is changed. Otherwise, the skin material becomes a composite material of different materials, and it is difficult to recycle the skin material remaining during molding.

The present invention has been made in view of the above-described problems of the prior art, and has been made by laminating a transparent or substantially transparent resin layer on the surface of a skin material in a mold. The purpose of the present invention is to obtain a laminated molded product having a good appearance.

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems, (1) In the lamination molding method according to the first invention, a skin material is arranged between a pair of dies and a back surface of the skin material is provided. And after filling the first resin between the cavity surface of the mold facing the back surface of the skin material, and between the surface of the skin material and the cavity surface of the mold facing the surface of the skin material. By forming a void and filling the void with a second resin, a transparent or substantially transparent resin layer is laminated on the surface of the skin material.

(2) The lamination molding method according to the second invention is characterized in that, after the first resin is filled in the first invention, the mold is slightly opened to form the surface of the skin material and the surface of the skin material. A gap is formed between the mold and the cavity surface facing the mold.

(3) The bonded molded product according to the third invention is characterized in that a skin material is disposed between a pair of molds, and a back surface of the skin material and a cavity surface of the mold facing the back surface of the skin material. After filling the first resin in between, forming a gap between the surface of the skin material and the cavity surface of the mold facing the surface of the skin material, and filling the gap with the second resin Thus, a transparent or substantially transparent resin layer is laminated on the surface of the skin material.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 6 relate to an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a lamination molding apparatus used in the method of the invention, and FIG. 2 is a mold showing steps in lamination molding. And FIG. 3 is a conceptual diagram for explaining a state inside the mold, and FIG. 3 is a cross-sectional view of a main part for explaining details of a portion A in FIG. FIG. 4 is a flowchart of the lamination molding method according to the embodiment of the present invention. FIG. 5 is a longitudinal sectional view illustrating the structure of the bonded molded product according to the method of the present invention. FIG. 6 is a flowchart of the lamination molding method according to the second embodiment of the present invention.

As shown in FIG. 1, the laminating apparatus 100 used in the laminating method of the present invention comprises a mold 10, a mold clamping unit 20, a multilayer injection unit 30, and a control unit 60.
It is composed of

Here, the mold 10 includes a fixed mold 3 attached to the fixed platen 1 and a movable mold 4 attached to the movable platen 2.
The molded product formed by the mold 10 used in the present embodiment has a structure in which it adheres to the cavity surface of the movable mold 4 and remains, and can be ejected from the movable mold 3 by a product ejection device and removed. It is a structure that can be done.

Hereinafter, the mold clamping device 20 used in this embodiment will be described. The mold clamping device 20 includes a fixed platen 1, a movable platen 2, a mold clamping cylinder 22, and a hydraulic source for supplying a desired oil pressure to the mold clamping cylinder 22. The movable platen 2 is not shown by the operation of the mold clamping cylinder 22. It is configured to be guided by the tie bar and move forward and backward with respect to the fixed platen 1.

In the present embodiment, the position sensor H is provided so as to detect the position of the movable platen 2. The output signal of the position sensor H which has detected the position of the movable platen 2 is:
The details are input to a control device 60 described later. Control device 6
0 indicates the position of the movable platen 2 based on the output signal of the position sensor H, and controls a mold clamping cylinder control valve that supplies hydraulic pressure to the mold clamping cylinder 22 to move the movable platen 2 at a desired position at a desired speed. By moving the movable mold 4 attached to the movable platen 2 to the desired position at a desired speed, the mold 10 can be freely opened and closed, and the mold can be clamped. ing.

In this embodiment, a toggle-type mold clamping device 20 as shown in FIG. 1 is used. However, the movable platen 2 is accurately and freely moved to a desired position at a desired speed. As long as the mold clamping device can apply a sufficient mold clamping force to the mold, it is not limited to the one described in the present embodiment, and a direct pressure type, or another type of mold clamping device may be used. It may be used in the present invention.

Next, the multilayer injection device 3 used in this embodiment
0 will be explained. The multilayer injection device 30 includes a first injection device 30A and a second injection device 30B shown in FIG. Then, the injection device 30A and the injection device 30B
Includes a barrel, a screw provided in the barrel, a hopper for supplying a core material resin into the barrel, an injection cylinder for moving the screw back and forth, a hydraulic motor for rotating the screw, A hydraulic source for supplying a desired hydraulic pressure to the cylinder and the hydraulic motor is provided, and a heater (not shown) is attached to the outer peripheral surface of the barrel.

The injection device 30A and the injection device 30B have a structure in which pellet-shaped resin is supplied from the hopper into the barrel by the rotation of the screw by a hydraulic motor. The resin is heated by a heater attached to the barrel, and is sent to the front of the screw while being melted by the kneading and compressing action due to the rotation of the screw.

In the present embodiment, the injection device 30
A rotary valve 3 is provided at the nozzle at the tip of the barrel A.
1A is arranged and the valve 31A rotates,
Open and close the resin flow path. Therefore, only when the valve 31A is in an open state, the molten resin sent to the front of the screw is extruded (sometimes referred to as injection) from the nozzle at the tip of the barrel by the screw advanced by the injection cylinder. )be able to.

Similarly, in the injection device 30B, a rotary valve 31B is disposed at the nozzle at the end of the barrel, and the molten resin is advanced by the injection cylinder only when the valve 31B is open. The screw allows extrusion from a nozzle at the tip of the barrel.

Next, the configuration of the control device 60 used in the present embodiment will be described. The control device 60 includes a mold clamping control unit that controls the mold clamping device 20 and a mold clamping condition setting unit (also referred to as a mold clamping condition setting unit), and an injection device control unit that controls the multilayer injection device 30 and an injection device. In this embodiment, the position sensor H detects the movement of the movable platen 2 in order to control the mold opening Lt of the mold 10 in this embodiment. The measurement is always performed, and the measurement result is input to the control device 60.

The steps of the bonding and forming method according to the first embodiment of the present invention performed using the bonding and forming apparatus having the above-described configuration will be described in detail below with reference to FIGS. 2 and 4. explain. Fig. 4 (1)
Start the molding (cycle start) at
In steps (2) and (3), the mold 10 is largely opened by the operation of the mold clamping device 20. Then, as shown in FIG. 2A, when the mold is largely open, the upper and lower rolls R, R are used to fix the skin sheet S, which is a skin material, to the fixed mold 3.
It is stretched with its surface facing the side, supplied between the fixed mold 3 and the movable mold 4, and the skin sheet S is set between the molds.

After setting the skin sheet S in the mold, FIG.
In step (4), the mold 10 is closed by the operation of the mold clamping device 20. At this time, while the skin sheet S is being pulled by the movable mold 4 while maintaining a constant tension, the fixed mold 3
It is pressed to the side and sandwiched between the fixed mold 3 and the movable mold 4.

In the first embodiment, when the skin sheet S is sandwiched between the fixed mold 3 and the movable mold 4,
As shown in FIG. 3, the gate end of the hot runner HA is configured to enter the back surface side of the skin sheet S. Also,
The skin sheet S is stretched and deformed along the cavity shape of the fixed mold 3 by being sucked by a vacuum suction device (not shown) so as to be in close contact with the mold cavity 5 of the fixed mold 3. It is arranged in the mold 10 in a shape substantially similar to the cavity shape. In the first embodiment, a hole is formed in a predetermined position of the skin sheet S in advance so that the gate tip of the hot runner HA easily penetrates the skin sheet S and enters the back side.
Of the gate can be penetrated.

In the first embodiment, when the mold is closed,
A sheet cutting mechanism (not shown) built in the mold 10 operates to cut the skin sheet S at both upper and lower ends of the mold 10. The skin sheet S used as the skin material in the first embodiment is a decorative sheet having a pattern printed on the front surface side,
Its material is polypropylene. However, the skin material that can be used in the present invention is not limited to the decorative sheet having the single-layer structure as in the first embodiment, and may be a sheet having a multilayer structure. Further, as the skin material, a skin material (sometimes referred to as a preform skin material) formed in advance by press molding or the like into substantially the same shape as the cavity shape of the mold may be used. The material may have a single-layer structure or a multilayer structure.

As the material forming the back surface (sometimes referred to as the back surface side) of the skin material, it is preferable to select a material having a fusibility with the molten resin of the core material as the first resin. If the back surface of the skin material and the molten resin of the core material do not have a fusion property, the back surface of the skin material is subjected to surface treatment or the like, so that the back surface of the skin material and the molten resin of the core material are fused or bonded. It is necessary to perform processing so as to be integrated. Similarly, the material forming the surface of the skin material is preferably selected from the transparent or substantially transparent material having a fusibility with the resin layer. It is necessary to apply a surface treatment or the like so that the surface of the skin material and the molten resin of the transparent or substantially transparent resin layer are integrated by fusion or adhesion.

Next, after the mold 10 is closed, FIG.
Proceed to steps (5) and (6). In the steps of FIGS. 4 (5) and (6), the switching valve 31A is switched from the closed state to the open state, and the injection device 30A performs the injection operation.
As shown in (1), the first resin (in the present embodiment, polypropylene) is injected and filled between the back surface of the skin sheet S and the cavity 5 of the movable mold 4 via the hot runner HA. After the first resin is injected and filled, the pressure is maintained and cooling is performed for a preset time.

In the step of FIG. 4 (7), the mold clamping device 20 starts the mold opening operation immediately after the completion of the cooling of the first resin. The mold opening operation is performed by monitoring the position of the movable platen 2 with the position sensor H, and setting a desired mold opening amount L set in advance in the mold clamping condition setting device.
Until t (2.0 mm in this embodiment), the mold is opened accurately. When the mold is opened, the first resin moves together with the movable mold 4 in a state of being fused to the back surface of the skin sheet S, so that a slight gap is generated between the surface of the skin sheet S and the fixed mold 3. .

In the first embodiment, after the mold is opened, the position of the movable platen 2 is controlled so that the movable mold 4 is always at a desired position (may be referred to as mold opening amount control). Of course, when the mold is opened, the cavity space formed between the two dies 3 and 4 is sealed so that the resin does not leak.
The relative positions of the dies 3 and 4 at this time are as shown in FIG.

The first resin (polypropylene) used in the first embodiment is a barrel setting temperature 200 of the injection device 30A.
Plasticized and melted at ℃.

4 (8) and (9), the switching valve 31B is switched from closed to open, and the injection device 30B
By the injection operation shown in FIG. 2, the second resin (in this embodiment, polypropylene which solidifies and becomes transparent) is converted into the second resin as shown in FIG.
As shown in (5), after injecting and filling the gap formed between the surface of the skin sheet S and the fixed mold 3, the pressure is maintained and the cooling is performed for a preset time. In the first embodiment, the surface of the skin sheet S and the cavity 5 of the mold facing the surface of the skin sheet S are opened by slightly opening the mold.
A gap is formed between the surface sheet and the surface of the skin sheet S by filling the gap with a second resin which becomes transparent when solidified in the gap, and formed as shown in FIG. Such a bonded molded product is formed. In addition, when the resin is injected and filled in the gap, and the pressure is maintained, a mold opening force of the resin that tries to open the mold 10 is generated. However, in the first embodiment, by increasing the mold clamping force, the mold clamping force is always increased. The mold opening was controlled so as to be constant.

The second resin, polypropylene, used in the first embodiment is plasticized and melted at a barrel setting temperature of 200 ° C. in the injection device 30B.

After the cooling is completed, the process proceeds to the step of FIG.
The mold opening control of the movable platen 2 is released. Then, FIG.
In the steps from 1) to (13), as shown in FIG. 2 (6), the mold 10 is largely opened by the operation of the mold clamping cylinder 22 and one cycle is completed by removing the molded product from the mold. .

According to the first embodiment of the present invention, since the skin sheet S having no clear resin layer is used as the skin material, the thickness of the skin material before being formed by the clear resin layer is increased. Since there is no such a problem that the winding length per weight of the skin material is shortened and the handling is reduced, the flexibility of the skin material is enhanced by reducing the thickness of the skin material, and the shapeability is improved. As a result, wrinkles do not occur when the skin material is sandwiched between the molds.

Further, since the clear resin layer is formed in the mold 10, the clear resin layer previously coated on the surface of the skin sheet S is rubbed or scratched when it is formed in the mold. It doesn't hurt you.

Further, in order to form the clear resin layer in the mold 10, by changing the type and amount of the clear resin layer injected into the mold 10, the color tone and the hardness of the bonded molded product are variously changed. A hard resin (for example, polystyrene, polycarbonate, or the like) that cannot be used by coating the surface of the skin sheet S can be used as the clear resin layer. Since the skin sheet S in the first embodiment has a single-layer structure, it is easy to recycle when the remaining skin material (cut portion or the like) obtained by cutting the skin material into a predetermined shape is disposed.

In the first embodiment, when the first resin is filled, the mold is slightly opened to make the mold open, so that the space between the first resin and the mold cavity 5 of the fixed mold 3 is increased. Although a void was created, a core (movable core) was arranged in the cavity of the mold to form a cavity variable mechanism, and after filling and cooling of the first resin was completed, the core was slid by driving means such as a hydraulic cylinder. The method of forming the gap by causing the gap may be used in the present invention.

Next, as a second embodiment of the present invention, a method of bonding and forming the steps shown in FIG. 6 will be described below. The second embodiment includes the above-described embodiment (first embodiment).
The same materials (skin material, first resin, and second resin) were used. Second
As shown in the flowchart of FIG. 6, this embodiment is the same as the first embodiment up to the step of FIG. 6D.

In the second embodiment, before the first resin is injected and filled, the mold clamping force of the mold is adjusted so that the mold 10 is opened by filling the first resin. Set to.
In the second embodiment, the injection filling pressure of the first resin is set to 300 kg / c.
m ² , and the projected area of the mold cavity was 600 cm ² , so that the mold clamping force was 30 tons (30000 kg), and the mold clamping force was such that the mold 10 was easily opened by filling with the first resin. It was adjusted.

Normally, since the mold 10 is clamped by a mold clamping force that does not open under the pressure at the time of filling the resin, when the injection filling pressure of the first resin is set to 300 kg / cm ² , the mold 1
A filling pressure of up to 300 kg / cm ² can occur within zero. However, since the average pressure of the resin filled in the mold 10 does not exceed a value obtained by dividing the mold clamping force by the projected area, the average pressure can be suppressed to a low value by keeping the mold clamping force low. . Therefore, in the second embodiment, the average pressure at the time of filling the first resin does not exceed 50 kg / cm ² , and the pressure applied to the skin sheet S can be reduced.

After the injection and filling of the first resin is completed, the switching valve 30A is switched from open to closed, and the mold clamping force set in advance in the mold clamping condition setting device is applied to the mold 10 to insert the resin into the mold. The molded product is cooled while applying pressure to the filled first resin (sometimes referred to as a pressure-holding step by mold clamping), thereby preventing sink marks caused by cooling the first resin.

Next, proceeding to the step of FIG. 6 (7), the mold clamping force is released and the mold 10 is opened to a desired position to open the mold.
In this case, in the second embodiment, injection filling is performed in a state where the mold opening amount is increased and the thickness is sufficiently larger than the thickness of the clear resin layer forming the void. Therefore, the second
In the embodiment, since the gap is large at the time of injection filling, the molten resin can be filled into the mold 10 at a low injection pressure. In this case, the gap is larger than the thickness of the clear resin layer to be formed. However, since the amount of the second resin to be injected and filled is only the amount of the clear resin layer to be formed, a corner of the enlarged gap is formed. Until now, the second resin is not filled.

After the completion of the injection filling of the second resin, the switching valve 30A is switched from the open state to the closed state, the mold opening amount of the mold is reduced, and the mold clamping force previously set in the mold clamping condition setting device is increased. Load 10 By closing the mold 10,
The molten resin filled in the mold 10 is pushed by the mold cavity 5 and flows through the cavity in the mold cavity 5 to fill every corner in the cavity.

After the second resin has been filled into all the corners of the gap, the amount of mold opening is further reduced to keep the second resin in a pressure-applied state (a pressure-holding step by mold clamping). ), And is cooled in that state. In the second embodiment, sinkage caused by cooling in the pressure holding step by the mold clamping can be prevented.

Here, in the pressure-holding step by the mold clamping, since the pressure is applied to the second resin over the entire surface of the mold cavity by decreasing the opening amount of the mold from large to small, the resin is generally supplemented from the gate portion. As compared with a typical pressure-holding step, the pressure applied to the clear resin layer becomes uniform everywhere, and the pressure applied to the clear resin layer can be suppressed as a whole. Therefore, compared to the general pressure-holding step, the pressure-holding step by the mold clamping can form a clear resin layer having less distortion and being optically excellent. The method of increasing the mold opening amount at the start of injection filling and decreasing the mold opening amount at the completion of filling may be referred to as an injection press.

After the cooling is completed, the process proceeds to the step of FIG.
The mold clamping force control of the movable platen 2 is released. Thereafter, the same steps as those in the first embodiment are performed, and the mold 10 is largely opened by the operation of the mold closing cylinder 22, and one cycle is completed by removing the molded product from the mold.

According to the second embodiment, the filling pressure is reduced at the time of filling the first resin to suppress damage to the skin sheet S, and the filling is performed at the time of filling the second resin. By lowering the pressure and making the pressure applied to the second resin uniform, a high-quality clear resin layer with less distortion can be formed.

[0050]

As described above, in the present invention, in the first invention, the bonding molding method is performed using a skin material having no clear resin layer. The resin layer increases the thickness of the skin material, shortens the winding length per weight of the skin material, and does not cause problems such as reduced handling. In addition, the thickness of the skin material is deteriorated, and the shapeability is deteriorated, so that it is sandwiched in a mold. In this case, it is possible to prevent a problem that the skin material is wrinkled in such a case and a problem that the skin material is damaged by rubbing with a mold or the like. Further, since the clear resin layer is formed in the mold, a hard resin (for example, polystyrene, polycarbonate, or the like) that cannot be used by coating the surface of the skin material can be used as the clear resin layer. Also, by changing the type of the clear resin layer formed by lamination by injection molding, the same skin material can be variously changed in color tone, hardness and the like.

In the second aspect of the present invention, the mold is slightly opened to form a gap between the surface of the skin material and the cavity surface of the mold facing the surface of the skin material. There is no need to provide a core or the like, and the bonding molding method can be performed using a mold having a simple structure.

The laminated molded product according to the third invention is a high-quality laminated molded product having a transparent or substantially transparent resin layer formed on the surface of the product and having a deep feeling.
Since the clear resin layer is formed in the mold, it is a beautiful molded article that is not damaged without being rubbed with the mold. In addition, by changing the type and amount of the clear resin layer injected into the mold, the color tone and hardness of the bonded molded product can be changed in various ways. The clear resin layer is formed by forming a thick hard resin on the surface of the skin material. When formed, a bonded molded article having extremely excellent scratch resistance and weather resistance is obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram according to an embodiment of a lamination molding apparatus applied to a method of the present invention.

FIG. 2 is a conceptual diagram illustrating a mold and a state in the mold showing steps in the embodiment of the lamination molding of the present invention, and (1) shows a state in which a skin material is set between the molds. (2) is a diagram showing a state in which the mold is closed and a skin material is set in the mold, (3) is a diagram showing a state in which the first resin is injected and filled, and 4) is a view in which a mold is opened to form a gap for filling the second resin, (5) is a view showing a state in which the second resin is injected and filled, and (6) is a molded product. FIG. 3 is a view showing a state where the is taken out of a mold.

FIG. 3 is a detailed view of a portion A in FIG. 2 (2).

FIG. 4 is a process flowchart according to an embodiment of the lamination molding method of the present invention.

FIG. 5 is a longitudinal sectional view illustrating the structure of a molded product according to the embodiment of the lamination molding method of the present invention.

FIG. 6 is a process flowchart according to a second embodiment of the lamination forming method of the present invention.

[Brief description of reference numerals]

 Reference Signs List 3 fixed mold 4 movable mold 5 mold cavity 10 mold 20 mold clamping device 30 multilayer injection device 30A injection device (first injection device) 30B injection device (second injection device) 31A valve 31B valve 60 control device 100 Lamination molding machine HA Hot runner HB Hot runner R Roll S Skin sheet

Claims (3)

[Claims] Claims: 1. A skin material is arranged between a pair of molds, and a first resin is filled between a back surface of the skin material and a cavity surface of a mold facing the back surface of the skin material. A void is formed between the surface of the skin material and the cavity surface of the mold facing the surface of the skin material, and the surface of the skin material is transparent or substantially filled by filling the void with a second resin. A bonding method comprising laminating and forming a transparent resin layer. 2. After filling the first resin, the mold is slightly opened to form a gap between the surface of the skin material and the cavity surface of the mold facing the surface of the skin material. The lamination molding method according to claim 1, wherein: 3. After disposing a skin material between a pair of molds and filling a first resin between a back surface of the skin material and a cavity surface of a mold facing the back surface of the skin material, A space is formed between the surface of the skin material and the cavity surface of the mold facing the surface of the skin material, and the space is filled with a second resin to make the surface of the skin material transparent or substantially transparent. A laminated product formed by laminating various resin layers.