JP5126647B2 - Multilayer molding method for resin, mold for multilayer molding, and multilayer molding apparatus - Google Patents

Description

  The present invention relates to multi-layer molding of a resin in which at least two types of resins are injected and molded into a mold cavity. When molding a multi-layer resin, the multi-layer molding can be changed in different layers. The present invention relates to a method, and a multilayer molding die and a multilayer molding apparatus suitable for use in the multilayer molding.

  2. Description of the Related Art Conventionally, a resin multilayer molding method in which two or more types of resins are injected into a mold and molded is widely known, and resin multilayer molded products are used in a wide range of fields.

  Multi-layer molded products with a foam layer have also been produced in the past, but in recent years, the market has become widespread, especially because the amount of resin used can be reduced to reduce weight, and its use in many product fields. Being considered. Along with the fact that weight reduction leads to cost reduction, we have further expanded the field of foam products.

As a technique for molding a multilayer molded article having a foam layer, a multilayer molding method disclosed in Patent Document 1 or Patent Document 2 is known.

JP 54-86550 A

Japanese Patent Publication No.46-29637

In Patent Document 1, after molding the first layer of resin in the mold, the mold is slightly opened to enlarge the mold cavity, and the second layer of resin is injected into the expanded mold cavity. A multilayer molding method for foaming a resin is disclosed. Further, Patent Document 1 further discloses a foam molding method in which a mold cavity is appropriately enlarged as necessary when foaming a second layer of resin. According to the multilayer molding method disclosed in Patent Document 1, the resin for molding the first layer can be different from the resin for molding the second layer. For example, by foaming only the resin of the second layer, It is also possible to mold a high-functional foam-molded product that has both a soft feel and rigidity.

  Similarly, Patent Document 2 discloses a multilayer in which a first layer of resin is molded in a mold, a mold cavity is expanded, and a second layer of resin is injected into the expanded mold cavity for foaming. A molding method is disclosed. Therefore, in the same way as the multilayer molding disclosed in Patent Document 1, in the multilayer molding method disclosed in Patent Document 2, the resin for molding the first layer and the resin for molding the second layer can be different. As a result, it is possible to mold a highly functional multilayer molded product.

  In addition, in order to secure a gap necessary for injecting the resin of the second layer, a method of slightly opening the mold as described above is known as a method of enlarging the mold cavity. There are several methods, for example, a method of expanding a mold cavity by die replacement as shown in Patent Document 3 is known.

JP-A-6-134803

  The technique disclosed in Patent Document 3 is a method of changing a shape of a mold cavity by exchanging a part of a mold during molding.

By the way, in order to adapt a multilayer molded product to a wider product field, a multilayer molded product having different shapes of the first layer and the second layer has been demanded.
For example, it is a multi-layer molded product that is shaped so that it can be easily attached to other parts by forming protrusions only on the second layer, or the second layer is a foam layer and the layer thickness is partially increased. It is a multi-layer molded product whose sound absorption and heat insulation properties are functionally enhanced by changing the size or size.

However, in the conventional multilayer molding method disclosed in Patent Document 1 or Patent Document 2 described above, the shape of the molded product molded in the second layer is limited by the shape of the molded product molded in the first layer. In addition, the shape of the molded product formed in the second layer has little freedom.
In other words, when the mold cavity is enlarged by opening the mold and the second layer resin is molded there, the second layer molded product is inevitably the same as the molded product molded with the first layer resin. The molded product is shaped so as to cover the outer shape with a resin having a uniform thickness in the mold opening and closing direction.
Therefore, the molded product of the second layer has a degree of freedom that can increase or decrease the overall thickness (dimension on the mold opening / closing direction side). In other words, the shape of the molded product molded in the second layer is almost determined by the shape of the molded product molded in the first layer.
For this reason, it is difficult to perform foam molding in which the outer shape of the second layer is partially changed to be different from the outer shape of the molded product molded in the first layer.

  In the multilayer molding method disclosed in Patent Document 3, the shape of the molded product formed in the second layer is determined by the shape of the molded product molded in the first layer as in Patent Document 1 or 2 described above. There is nothing. However, in order to replace the mold during molding, a special mold exchanging device is necessary, and the size of the molding machine is increased and the cycle time is increased. Furthermore, there is a problem that a mold for replacement during molding is necessary and expensive.

The present invention has been made in view of the above problems, and a multilayer molded product in which the shapes of the first layer and the second layer are different for the purpose of expanding the use range of the multilayer molded product to a wider product field. The present invention provides a multilayer molding method and a multilayer molding apparatus that are suitable for manufacturing the present invention.

In order to achieve the above object, a method for multilayer molding of a resin according to the present invention includes:
(1) Filling the mold cavity with the first resin and molding the first layer, and forming the first layer and then expanding the volume of the mold cavity by mold opening operation the parts, and filling the second resin having a foaming, after filling the second resin, further, the mold opening operation to expand the volume of the mold cavity, foaming of said second resin by the steps of forming the second layer, in a multilayer molding method of a resin having a placed incorporate nested moving retractably with respect to the mold cavity as part of the mold cavity surface, said When foaming the resin of No. 2, the shape of the mold cavity is changed by moving the insert forward or backward in the mold cavity direction.

Furthermore, in order to achieve the above object, a multilayer molding apparatus for resin according to the present invention comprises:
( 2 ) At least two or more resin injection mechanisms, a multilayer molding die capable of molding at least two or more resins, and a clamping device for clamping the multilayer molding die, a step of forming the first layer is filled with a first resin, after molding the first layer, the gap portion formed by expanding the volume of the mold cavity by mold opening operation, the having foamable After filling the second resin and filling the second resin, the mold is further opened to expand the volume of the mold cavity, foam the second resin, and mold the second layer. in a multilayer molding apparatus of the resin for performing the steps, a to said multi-layer molding die, as well as by arranging the nest into the mold to form a part of the mold cavity surface in nesting, the mold cavity of the nest Slidably supported in the mold so that it can move forward and backward in the direction, and A driving device for coupling to the nest by placement into the mold, when the foaming of said second resin has a structure in which the nest is advanced also retracted relative to the mold cavity surface.

( 3 ) In the multilayer molding apparatus according to ( 2 ), the mold clamping device includes a toggle type mold clamping mechanism.

  According to the multilayer molding method of the present invention, multilayer molded products having different shapes of the first layer and the second layer can be manufactured without using a special device such as a mold changer.

  Further, when a foamable resin (for example, a resin in which a foaming agent is mixed in advance) is used as the resin for forming the second layer, the sound absorption is achieved by partially increasing or decreasing the layer thickness. A multilayer molded article with improved properties and heat insulation can be obtained.

  Furthermore, since the position of the movable plate can be controlled with high accuracy by using the toggle type clamping mechanism as the clamping mechanism of the multilayer molding apparatus according to the present invention, the volume of the mold cavity can be controlled with high precision. It is possible to obtain a multilayer molded article having uniform and fine foamed cells and a highly accurate foaming ratio.

Hereinafter, a preferred example of a mode for carrying out the present invention will be described in detail with reference to the drawings. 1 and 2 relate to an embodiment of the present invention, FIG. 1 is a cross-sectional view of a principal part showing a schematic configuration of a multilayer molding die, and FIG. 2 is an explanatory diagram conceptually showing an overall configuration of the multilayer molding apparatus. It is.
3 and 4 are conceptual diagrams for explaining the steps of the multilayer molding method according to the embodiment of the present invention. FIG. 5 is an explanatory diagram for explaining another drive mechanism for driving the slide core.

  A multilayer molding apparatus 100 used in the embodiment shown in FIG. 2 includes a mold 10, a mold clamping apparatus 20, an injection apparatus 30, and a control apparatus 60.

  Hereinafter, the structure of the mold 10 will be described. 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 fixed mold 3 and the movable mold 4 have a half-push structure in which the fitting parts are fitted together. The mold cavity 5 is formed in the fitted state.

The fitting portion of the half-pressing structure is formed over the entire circumference of the mold cavity, and even after the molten resin is filled, the mold cavity can be opened or closed slightly to increase or decrease the volume of the mold cavity. The resin filled in is prevented from leaking out of the mold 10.

  The fixed mold 3 constituting the mold 10 includes a hot runner for introducing a resin injected from a first injection unit 31 described later to the mold cavity 5 from the introduction port 3A, and a second injection described later. A hot runner for introducing the resin injected from the unit 32 into the mold cavity 5 through the introduction port 3B, and the former hot runner has a first valve gate 6A (also referred to as a first valve 6A). The latter hot runner includes a second valve gate 6B (sometimes referred to as a second valve 6B).

Hereinafter, the multilayer molding die 10 according to the present embodiment will be described.
In the multilayer molding die 10 according to the present embodiment, two slide cores are arranged as a nesting in the die to form a part of the die cavity surface. As shown in FIG. A mold cavity surface is formed by incorporating the first slide core 7 (first insert 7) and the second slide core 8 (second insert 8) as a part of the cavity.

Here, the mold 10 according to the embodiment shown in FIG. 1 will be described. The first slide core 7 and the second slide core 8 are round holes formed in the mold cavity surface of the movable mold 4 and extending in the mold opening / closing direction. It is incorporated by being inserted into (sometimes referred to as a cylinder part), and is arranged so as to be slidable in the cylinder part. In the embodiment shown in FIG. 1, components for constituting a hydraulic cylinder such as a piston rod are inserted into the cylinder portion, and the components such as the piston rod and the cylinder portion are adjacent to the mold cavity 5. Forming a hydraulic cylinder. The first slide core 7 and the second slide core 8 are connected to the piston rod tip of the hydraulic cylinder formed adjacent to the mold cavity 5.
In the present embodiment, in order to simplify the structure, the hydraulic cylinder as described above is used as a drive machine. However, the drive machine is a commercially available general purpose as in the embodiment shown in FIG. A driving system such as a hydraulic cylinder Y or an electric cylinder may be driven by connecting the connecting flange F or a cam (not shown) to the slide core.

In the present embodiment, the first slide core 7 and the second slide core 8 can be moved forward or backward in the mold cavity direction by the above-described configuration.
A hydraulic line P1 or P3 is connected to the rod side of the hydraulic cylinder, and a hydraulic line P2 or P4 is connected to the piston head side of the hydraulic cylinder.
Accordingly, in the first slide core 7, the first slide core 7 moves forward in the mold cavity direction side (in this embodiment, the fixed mold 3 side) by applying hydraulic pressure to the hydraulic line P2 and extracting oil from P1. Then, the first slide core 7 projects into the mold cavity, and the volume of the mold cavity is reduced by the amount of projection of the first slide core 7.
In the first slide core 7, by applying oil pressure to the hydraulic line P <b> 1 and extracting oil from P <b> 2, the first slide core 7 retreats away from the mold cavity, so that the first slide core 7 is The volume of the mold cavity is increased by the amount retracted from the mold cavity direction.

Similarly, for example, in the second slide core 8, oil pressure is applied to the hydraulic line P <b> 4 and oil is extracted from P <b> 3, so that the second slide core 8 is on the mold cavity direction side (in this embodiment, on the fixed mold 3 side). ), The second slide core 8 protrudes into the mold cavity, and the volume of the mold cavity is reduced by the amount of protrusion of the second slide core 8.
Further, in the second slide core 8, by applying oil pressure to the hydraulic line P <b> 3 and extracting oil from P <b> 4, the second slide core 8 moves backward so as to be separated from the mold cavity 5, and the first slide core 7. Is configured such that the volume of the mold cavity is increased only by a portion retracted from the mold cavity direction.

  Here, in the embodiment shown in FIG. 1, the first slide core 7 and the second slide core 8 are arranged to partially increase or decrease the thickness of the molded product of the second layer. ing.

It should be noted that the drive method, shape, etc. of the nesting used in the present invention are not limited to the above-described embodiments, and the drive method, shape, etc. of the nesting are adapted to the functions and shapes required for the product. Should be decided.
For example, in the embodiment shown in FIG. 1, in order to form an engagement portion with other parts in the molded product portion of the second layer, the slide cores 7 and 8 are formed so as to have a protruding portion and a fitting portion. The shape is determined, and the shape may be, for example, a prismatic shape, an L shape, or the like according to the required purpose. After forming the second layer, the molded product is the mold 10. Any shape can be used as long as it can be removed from

Further, the number of slide cores as the nesting can be increased or decreased according to the product shape, and the number may be adjusted as appropriate according to the shape required for the product.
Further, in the embodiment shown in FIG. 1, the hydraulic cylinder directly connected to the slide cores 7 and 8 is installed in the movable mold 4. However, the present invention is not limited to this, and the technical idea of the present invention is not deviated. Within the range, if necessary, a slide core as a nesting may be arranged in the fixed mold 3.

  Next, as shown in FIG. 2, the mold clamping device 20 includes a toggle-type mold clamping mechanism 21 driven by a fixed platen 1, a movable platen 2, and a link driving mechanism that is moved by a mold clamping servomotor 20B. I have. The movable platen 2 is guided by a tie bar (not shown) installed between the fixed platen 1 and the end plate, and can be moved forward and backward together with the movable die 4 by a toggle type mold clamping mechanism 21.

In this embodiment, a stroke sensor (not shown) is attached to the crosshead drive shaft of the link drive mechanism provided in the mold clamping device 20 in order to detect the position of the crosshead. The movable platen position sensor (not shown) is arranged to detect the position of the movable platen 2 as a mold open / close stroke sensor for detecting the die open / close stroke.

  The multilayer injection device 30 shown in FIG. 2 includes two machines, a first injection unit 31 and a second injection unit 32, as the injection devices. The first injection unit 31 is built in the barrel 31A and the barrel 31A. A screw, a hopper for supplying a thermoplastic resin material to the barrel 31A, and a screw driving device 31C for moving the screw forward and backward or rotating are provided. A heater (not shown) is attached to the outer peripheral surface of the barrel 31A.

  Similarly, the second injection unit 32 is provided with a barrel 32A, a screw provided in the barrel 32A, a hopper for supplying a thermoplastic resin material to the barrel 32A, and a screw driving device 32C for moving the screw forward and backward. . A heater (not shown) is attached to the outer peripheral surface of the barrel 32A.

Further, in the first injection unit, the thermoplastic resin material is supplied from the hopper into the barrel 31A by rotating the screw, and the supplied thermoplastic resin material is supplied into the barrel 31A. It is heated by the attached heater, and melted by receiving a kneading compression action by the rotation of the screw and sent to the front of the screw.
The molten resin sent to the front of the screw can be filled into the mold cavity 5 by the screw from the nozzle 31B attached to the tip of the barrel 31A via the first valve 6A attached to the fixed die 3 or the like. .

  Similarly, in the second injection unit, the mold cavity 5 can be filled from the nozzle 32B attached to the tip of the barrel 32A through the second valve 6B attached to the fixed mold 3 or the like.

  The control device 60 controls the mold clamping control unit for controlling the opening and closing of the mold and the mold clamping force, and the first and second injection units to plasticize the thermoplastic resin material and mold the mold cavity 5 of the molten resin. The injection control part which controls filling to is provided.

  The mold clamping control unit of the mold clamping device 20 can set the opening / closing position of the movable mold 4 in multiple stages as required, and set the opening / closing speed of the movable mold 4 to be variable according to the mold opening / closing position as necessary. A mold clamping condition setting machine is provided, and based on the set value, the movable mold 4 during the mold opening / closing period (that is, during the period from the start of mold closing to the completion of mold opening after final mold clamping) The opening / closing position and opening / closing speed of the can be controlled. Further, the mold clamping condition setting machine can set the opening / closing speed of the movable mold 4 so as to change in multiple stages according to the opening / closing position of the movable mold 4, and also set so as to change continuously. You can also.

  The opening / closing position of the movable mold 4 is controlled by the position data of the crosshead detected during the mold closing operation based on the positional relationship data of the crosshead corresponding to the position of the movable platen 2 stored in advance. It has become.

In the following, a preferred example of a multilayer molding method that is useful for understanding the present invention will be described with reference to FIG.
First, as a first step, the mold 10 is clamped between the movable platen 2 and the fixed platen 1 by the mold clamping device 20 as shown in FIG. A mold cavity 5 is formed between 4.

Next, as the second step, as shown in FIG. 3B, the first resin is fed from the first injection unit 31 into the mold cavity 5 with the first valve 6A switched and opened. Fill. Then, after completion of filling, the first valve 6A is switched and closed for a predetermined time.
In the present embodiment, the resin to be filled as the first resin is a thermoplastic resin that is in a molten state. Accordingly, the resin filled in the mold cavity 5 is held there for a predetermined time and then cooled and solidified to form the first layer of the molded product.
In this step, the cooling time of the first resin is set so that when the mold 10 is slightly opened and when the second resin is filled in the mold cavity in the step described later, This is the time required to solidify the first layer to such an extent that it will not be damaged.

  Next, as a third step, as shown in FIG. 3 (3), by operating the mold clamping device 20, the movable mold 4 is moved slightly in the direction of the anti-fixed mold 3, and the mold cavity 5. The volume is increased, and a gap is formed between the molded product of the first layer and the mold cavity surface of the movable mold 3 to form a gap. In addition, this space | gap part becomes a new cavity space for filling the 2nd resin mentioned later.

As the fourth step, as shown in FIG. 3 (4), the first slide core 7 and the second slide core 8 are driven to change the shape of the mold cavity 5.
In the process shown in FIG. 3, oil is supplied to the hydraulic lines P2 and P3 to apply oil pressure, and the oil is extracted from the hydraulic lines P1 and P4 so that the first slide core 7 is moved in the direction of the mold cavity 5 (main In the embodiment, the second slide core 8 is moved in the direction of the anti-mold cavity 5 (in the present embodiment, the anti-fixed mold 3 side direction) by moving forward in the direction of the fixed mold 3 side). Retreated from the direction.

  In the present embodiment, the hydraulic cylinder method is selected as the driving method for the slide cores 7 and 8 that are nested. However, the driving method that can be applied to the present invention is not limited to this, for example, It is possible to adopt a known drive system such as a pneumatic cylinder system, an electric system, a cam system, or a spring system. Further, in order to improve the movement accuracy of the moving amounts of the slide cores 7 and 8 that are nested, it is preferable to use a limit sensor that determines a forward limit and a backward limit, a movement amount detection sensor, or the like.

  Further, in the present embodiment, after the completion of the third step, the process proceeds to the fourth step, but for the third step and the fourth step, the nesting operation is performed with the first layer of the molded product and the mold opening operation. It is also possible to carry out the process at the same time by overlapping within a range that does not adversely affect the above.

  Next, as a fifth step, as shown in FIG. 3 (5), the mold cavity 5 in which the second resin is expanded from the second injection unit 32 with the second valve 6B switched and opened. Fill inside. Then, after the filling is completed, the second valve 6B is switched and closed, and is held for a predetermined time to be cooled and solidified.

When the second layer molded product is solidified to such an extent that it can be removed from the mold 10 by holding for a predetermined time, the process proceeds to the sixth step, and the mold clamping device 20 is operated as shown in FIG. As a result, the molded product is taken out from the mold 10.
In the present embodiment, a multi-layer molded product in which the protruding portion and the fitting portion are formed in the molded product portion of the second layer and the engaging portion with other components is formed can be molded by the above-described steps.

  In the present invention, the thermoplastic resin material used for the first layer and the second layer is not particularly limited, but the first layer and the second layer are joined and integrated in the mold. Resins are preferred, for example, olefin resins such as polypropylene and polyethylene, acrylic resins such as polystyrene and polymethyl acrylate, polyamide resins such as 6-nylon, polyester resins, ABS resins, polycarbonate resins, and thermoplastic elastomers. Can be mentioned.

Hereinafter, another preferred example of multilayer molding according to the present invention will be described with reference to FIG. 4 with a focus on the differences from the embodiment described in FIG.
The process illustrated in FIG. 4 is a suitable form when a molten resin having foamability is used as the second resin for molding the second layer, for example, by previously mixing a foaming agent.

First, the first to fourth steps are performed in the same manner as in the embodiment shown in FIG.
As a fifth step, as shown in FIG. 4 (5), in the mold cavity 5 in which the second resin is expanded from the second injection unit 32 with the second valve 6B switched and opened. To fill. Then, after the filling is completed, the second valve 6B is switched to a closed state.

In addition, it does not specifically limit as a foaming agent used for this invention, A chemical foaming agent and a physical foaming agent can be used. Examples of the chemical foaming agent include inorganic foaming agents represented by sodium bicarbonate and organic foaming agents represented by azodicarbonamide (ADCA).
Examples of the physical foaming agent include inert gas such as carbon dioxide, nitrogen, and a mixed gas of carbon dioxide and nitrogen, air, and the like. These foaming agents may be used alone or in combination.

  Next, the process proceeds to a sixth step, and as shown in FIG. 4 (6), the mold clamping device 20 is operated to move the movable mold 4 in the anti-fixed mold 3 direction. Then, the volume of the mold cavity 5 is further expanded so that the second resin can expand and expand to the required magnification.

In the embodiment shown in FIG. 4, after the first slide core 7 and the second slide core 8 are driven and moved to predetermined positions in the fourth step, the second resin is injected, and thereafter In the sixth step, the mold cavity is expanded to the extent necessary for foaming.
However, the scope of application of the present invention is not limited to this. For example, after the mold cavity is expanded to the extent necessary for foaming, or after the mold cavity is expanded to the extent necessary for foaming, the first The slide core 7 and the second slide core 8 may be driven to move to a predetermined position.

  In particular, when the insert is moved so as to protrude into the mold cavity and the fluidity of the molten resin as the second resin is poor, the mold filling of the molten resin is facilitated. Since the advantageous effect can be expected, after the mold cavity 5 is expanded to the extent necessary for foaming, or at the same time as the mold cavity 5 is expanded to the extent necessary for foaming, the first slide core 7 and the first It is preferable to drive the two-slide core 8 to a predetermined position. When filling the mold cavity with the second resin before foaming, the resin flow is better when there are no protrusions or fitting parts in the mold cavity. Therefore, it is advantageous after filling the resin.

  Then, after the foaming is completed, when the second layer of the foam molded product is solidified to such an extent that it can be taken out from the mold 10, the process proceeds to the seventh step, as shown in FIG. 4 (7). Then, the molded product is taken out from the mold 10 by operating the mold clamping device 20.

  Note that the present invention is not limited to the above embodiments, and it goes without saying that various changes and improvements can be added without departing from the spirit of the present invention.

It is principal part sectional drawing which showed the general | schematic structure in order to demonstrate the structure of the metal mold | die for multilayer molding in connection with embodiment of this invention. The embodiment of the present invention is an explanatory diagram illustrating the overall configuration of a dependency multilayer molded device. It is a diagram of order to explain the process of the multilayer molding method relates to embodiments that can be used as a guide to understanding the present invention. It is a figure for demonstrating the process of the multilayer molding method in connection with embodiment of this invention. It is a figure for demonstrating the drive mechanism of a nesting in connection with other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed platen 2 Movable platen 3 Fixed type | mold 4 Movable type | mold 5 Mold cavity 7 1st slide core 8 2nd slide core 10 Mold for multilayer molding 20 Clamping device 21 Toggle type clamping mechanism 30 Multilayer injection device 31 1st injection Unit 32 Second injection unit 3A First resin inlet 3B Second resin inlet 60 Controller 6A First valve (first valve gate)
6B Second valve (second valve gate)
P1 Hydraulic line (For first slide core, rod side)
P2 Hydraulic line (For first slide core, head side)
P3 Hydraulic line (for second slide core, rod side)
P4 Hydraulic line (for second slide core, head side)
100 multilayer molding machine 20B servomotor for mold clamping 31A barrel (first injection unit)
31B nozzle (first injection unit)
31C Screw drive (first injection unit)
32A barrel (second injection unit)
32B nozzle (second injection unit)
32C screw drive (second injection unit)

Claims (3)

Filling the mold cavity with the first resin to form the first layer;
Filling the void formed by enlarging the volume of the mold cavity by mold opening operation after molding the first layer, and filling the foamed second resin ;
After filling the second resin, further, mold opening operation to expand the volume of the mold cavity, foam the second resin, and mold the second layer ;
In the multilayer molding method of resin comprising
A nest that moves forward and backward with respect to the mold cavity is incorporated and arranged as a part of the mold cavity surface , and when the second resin is foamed, the nest is moved forward or backward in the direction of the mold cavity. A resin multilayer molding method characterized by changing the shape of a mold cavity. Comprising at least two or more resin injection mechanisms, a multilayer molding die capable of molding at least two or more resins, and a clamping device for clamping the multilayer molding die,
Filling the mold cavity with the first resin to form the first layer;
Filling the void formed by enlarging the volume of the mold cavity by mold opening operation after molding the first layer, and filling the foamed second resin ;
After filling the second resin, further, mold opening operation to expand the volume of the mold cavity, foam the second resin, and mold the second layer ;
In a resin multilayer molding apparatus
The mold for multi-layer molding has a nesting in the mold so that a part of the mold cavity surface is formed by nesting, and the mold is slidable so that the nesting can move forward and backward in the direction of the mold cavity. When the second resin is foamed by disposing a driving device that is supported inside and connected to the insert in the mold, the insert moves forward or backward with respect to the mold cavity surface. A resin multilayer molding apparatus characterized by the above. 3. The resin multilayer molding apparatus according to claim 2, wherein the mold clamping device includes a toggle type mold clamping mechanism.

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