JPH11198174A - Method and apparatus for multilayer molding of resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously satisfy a soft feeling, cushioning properties, a touch feeling or a quality feeling by injecting a second layer molten resin becoming an intermediate material into the space formed by a first layer filler becoming a core material and a skin material to fill the space and applying mold clamping force to the whole. SOLUTION: A shut-off valve 31A is opened to inject a molten resin of a first layer becoming a core material into a mold cavity to fill the cavity. Next, a skin material is inserted into the gap between a movable mold 4 set to a mold opening state and a first layer core resin molded object and mold clamping operation is performed corresponding to the mold opening quantity set value set by a mold clamping condition setting part 66. Next, a shut-off valve 31B is opened to inject a molten resin of a second layer becoming an intermediate material into the secondary space part formed by the core molded object and a movable mold to fill the space part. Next, the injection filling completion of the molten resin of the second layer is detected by a timing control part 63 and, thereafter, the shut-off valve 31B is closed and mold closing operation is performed on the basis of a preset mold clamping operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method in which a first layer core material molten resin is injected and filled in a mold, and then a second layer intermediate material molten resin is laminated on the surface of the first layer core material filling. at the same time,
The present invention relates to a multilayer molding method and a multilayer molding apparatus for a resin obtained by fusing and integrating a decorative skin material on the surface of a second layer intermediate material.

[0002]

2. Description of the Related Art In recent years, resin molded parts used for automobiles, home appliances, building materials, and the like are increasingly required to have added value.
Along with demands for providing added value such as touch feeling and texture as well as soft feeling and cushioning property, demands for cost reduction by reducing the number of molding steps are increasing. In order to cope with these, conventionally, the following multilayer molding is performed. That is, after a skin material (decorative material) is inserted and set in a mold, and the core material is injected and filled in a mold-clamped or mold-opened state, an injection holding pressure or a mold-clamping force is applied and the core material is removed. Cooling. After the completion of the cooling, the molded product is taken out after opening the mold to obtain a surface decorative molded product in which a skin material (decorative material) is fused and integrated to the surface of the core resin molded product ( Skin material insert molding). The first layer resin (core material) was injected and filled in the mold, and the second layer resin (decorative material) was injected and filled while the mold was partially or completely retracted or the mold clamping force was reduced. Thereafter, the mold is advanced or a mold clamping force is applied, and the filled resin is cooled. After completion of cooling, the molded product is opened and the molded product is taken out to obtain a surface decorative molded product in which the decorative resin is laminated and integrated on the surface of the core resin (sandwich molding).

[0003]

However, such a conventional method has the following problems. (1) In the case of insert molding of the skin material, a skin material with a foam layer laminated on the back surface (core material resin side) is used to give a soft feeling and cushioning property. The foamed layer is easily melted and damaged by the resin material, and the soft feeling and the cushioning property are lost. As a countermeasure, a skin material in which a protective layer having heat resistance and pressure resistance is laminated on the back surface of the foam layer is used. However, the cost of the skin material is increased and it is difficult to completely protect the foam layer. (2) Even in sandwich molding, there are many cases where a feeling of touch or texture is required, but a feeling of texture or texture cannot be imparted only by molding resin. A brushed cloth or a woven cloth is ideal as a decorating material as a method of giving a feeling of touch or texture, and conventional sandwich molding could not cope with it. When the softness and cushioning property and the feel and texture are required at the same time, it has been difficult to cope with the conventional molding method.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems and obtain a multilayer molded product of resin stably at a high quality with a simple control, in the present invention, in the first invention, In a preset first mold clamping state, a first layer molten resin serving as a core material is injected and filled into a mold space formed by a movable mold and a fixed mold, and then both molds are relatively moved. Separated to maintain a predetermined mold opening set value, a skin material is interposed between the first layer filling and the mold, and then the first layer filling is performed in a preset second mold clamping state. After injecting and filling a second layer molten resin as an intermediate material into a space formed by the object and the skin material, a mold clamping force is applied to the first layer core material resin, the second layer intermediate material resin and the skin. Lamination fusion bonding was performed in the order of materials. In the second invention, the first mold clamping state is a mold clamping force that does not cause the mold to open due to the resin pressure of the filled first layer core material molten resin until the mold filling is completed. And hold it. In the third invention, the first mold clamping state is such that the first mold clamping force that allows the mold to be opened by the resin pressure of the filled first layer core material molten resin during the injection filling is applied to the mold. The mold was loaded, and then the pressure was increased to a second mold clamping force for the purpose of shaping the first layer core material resin. In the fourth invention, the first mold clamping state is such that the two molds are separated from each other and held at a predetermined mold opening set value during injection filling, and thereafter, the first layer core material resin is applied. A mold clamping force for shaping was applied to the mold. Further, in the fifth invention, the second mold clamping state includes applying a mold clamping force to the mold to allow the mold to open by the resin pressure of the filled second layer intermediate material molten resin. And In the sixth invention, in the second mold clamping state, the two molds are separated from each other and held at a predetermined mold opening amount set value. In the seventh invention, a multilayer injection mechanism for injecting and filling the first and second layers of molten resin into a mold space formed by a movable mold and a fixed mold, and a skin material is interposed in the mold. And a loading / unloading mechanism for transporting the multilayer molded product out of the mold, and a mold clamping in a first and second mold clamping states when the first and second layers of molten resin are injected and filled into the mold space. The force is set in multiple steps or the mold opening set value is set in multiple steps, the mold opening set value when the skin material is interposed in the mold, and the mold clamping force or mold after injection filling of the second layer molten resin. A mold clamping condition setting unit for setting and inputting an opening amount, a mold clamping control unit for controlling a mold clamping mechanism based on a signal from the mold clamping condition setting unit, and a mold clamping device operated by a signal from the mold clamping control unit. And a resin multilayer molding apparatus having the following formula:

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, after a first-layer resin (core layer) is injected and filled, the mold is temporarily opened, and a skin material (decorative layer) is inserted and set in a mold. Clamp the mold. Subsequently, after injecting and filling the second layer resin (intermediate layer), an injection holding pressure or a mold clamping force is applied and the filled resin is cooled. After the completion of the cooling, the molded product is taken out after opening the mold to obtain a multilayer molded product of the core layer / intermediate layer / surface decoration layer. The material of each layer can be selected according to the quality and function required for the molded article, and the surface decoration performance can be freely imparted by combining these layers. For example, a hard material resin (providing the shape retention and strength of the molded product) for the core layer, a foamed resin or a soft resin (for imparting a soft feeling or cushioning property) for the intermediate layer, and a brushed cloth or a woven cloth (touch) for the skin decoration layer. By adding a texture or texture)
Even without the conventional heat-resistant and pressure-resistant protective layer laminating treatment, soft feeling, cushioning property, touch feeling and texture can be simultaneously provided, and the skin-decorated molded product which was impossible with the conventional molding method can be efficiently used. It can be supplied stably. By controlling the mold clamping force or the mold opening amount in multiple stages as needed during the injection filling of the first layer resin and the second layer resin, it is possible to suppress the flow rate and the resin pressure of the resin during the injection filling, Damage to the skin material during molding can be reduced.
In addition, due to the holding pressure from the mold clamping side, the resin pressure in the mold is made uniform, a molded product without deformation or warpage can be obtained, and a high quality molded product with excellent surface decoration performance can be obtained. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 relate to an embodiment of the present invention,
1 is an overall configuration diagram of a resin multilayer molding apparatus, FIG. 2 is a flowchart of a resin multilayer molding process, and FIG. 3 is an operation explanatory diagram for explaining a molding operation of multilayer molding.

As shown in FIG. 1, a multilayer molding apparatus 100 according to the present invention includes a mold apparatus 10, a mold clamping apparatus 20, an injection apparatus 30, a control apparatus 60, and a not-shown skin material or molded article loading / unloading apparatus. Be composed. The mold apparatus 10 includes a fixed mold 3 attached to a fixed platen 1 and a movable mold 4 attached to a movable platen 2. The movable platen 2 and the movable mold 4 are formed by a mold clamping cylinder of a mold clamping device 20. It is configured to be able to move forward and backward at 22. The mold clamping device 20 is provided with two dies 3, 4 of the mold device 10.
The movable mold 4 is guided by a tie bar (not shown) with respect to the fixed mold 3 to move forward and backward with respect to the fixed mold 3.

The injection device 30 comprises a first injection unit 30A for supplying the first layer core material molten resin into the cavity 5, and a second injection unit 30B for supplying the second layer intermediate material molten resin into the cavity 5. The molten resin can be supplied from the sides and below the fixed mold 3 via paths connected to the cavity 5. Each path is provided with shut-off valves 31A and 31B for shutting off and communicating the resin flow path.

Next, the control device 60 will be described. As shown in FIG. 1, the control device 60 includes a mold clamping control unit 61, a timer 62, a timing control unit 63, an injection control unit 64, a mold opening amount sensor 65, a mold clamping condition setting unit 66, and the like. The timing control unit 63 is connected to the mold clamping control unit 61, the injection control unit 64, and the timer 62.
Is connected to the mold opening sensor 65 and the mold clamping condition setting unit 66.

FIG. 2 shows a flow chart of the resin multi-layer molding process, which will be outlined below. The first mold clamping state has the following three patterns, one of which is selected.

Pattern A is a method in which the mold is clamped by a mold clamping force that does not generate burrs during the injection filling of the first layer resin, and this state is maintained until the injection filling is completed. This pattern A is selected when a high-flow resin is used as the first-layer resin, or when the mold is easy to flow. The pattern B is injection-filled in a state where the mold is clamped with a small mold-clamping force such that the mold opens appropriately when the first layer resin is injected and filled. This is a method of shaping the first layer resin by increasing the mold clamping force at any time during injection filling or at the completion of injection filling. This pattern B is selected when a low-flow resin is used as the first layer resin, or when a mold or a thin wall shape is difficult to flow. As means for shaping the first layer resin, both molds are held at a mold clamping position set value that gives a compressing action (shaping action) in addition to the above-described mold clamping force load (pressure control). Means for controlling (position control) is also possible. The pattern C is injected and filled with the first layer resin in a state where the mold is clamped and held at a predetermined mold opening position. This is a method of shaping the first layer resin by applying a mold clamping force at an arbitrary point during the injection filling or at the completion of the injection filling. This pattern C is selected when a resin having low fluidity is used as the first layer resin. Also in this case, the first layer resin can be shaped by position control as in the case of the pattern B.

When the pattern B or the pattern C is selected, the mold is slightly opened at the time of injection filling, so that the resin flow path in the mold is enlarged and flows easily, and the air and gas in the mold are easily released. In addition, the filling behavior of the resin becomes smooth. Therefore, the injection filling pressure is reduced, the injection time is shortened, the decrease in the resin temperature during filling is reduced, and the molding cycle can be shortened.

The second mold clamping state has the following two patterns, one of which is selected. The pattern D is injection-filled in a state where the mold is clamped with a small mold-clamping force such that the mold opens appropriately when the second layer resin is injected and filled. At any time during injection filling or at the completion of injection filling, the mold clamping force is increased and the second
This is a method of shaping the layer resin. Since the mold opens slightly during injection filling, the resin flow path in the mold expands and flows more easily, the resin pressure can be kept low, and the thermal and pressure external forces applied to the skin material are reduced. . Therefore, damage to the skin material during injection filling of the second layer resin can be reduced. The pattern E is injected and filled with the second layer resin in a state where the mold E is held at a predetermined mold opening position. This is a method in which a mold clamping force is applied at an arbitrary point during injection filling or at the time of completion of injection filling to form the second layer resin. The effect of preventing damage to the skin material is higher than that of pattern D, and particularly, the effect of preventing damage to the skin material near the gate portion during injection filling is large. The second
Also in the case of the mold clamping state, the first layer resin can be shaped by position control in addition to the mold clamping force load (pressure control) as in the case of the first mold clamping state.

Based on the above, the first layer core material resin is selected from hard resin materials (for example, ABS resin) and second layer resin, which are hard resin materials for the purpose of maintaining the shape of the molded article and imparting strength. Laminate made of elastomer from soft resin material for softness and cushioning as an intermediate resin, and leather (synthetic leather) from decorative material for skin feel and luxury as a skin material The molding operation in actual operation will be described by taking a molded product as an example. Since a resin having poor fluidity is used as the core material, the pattern C is selected as the first mold clamping state. A leather made of polyvinyl chloride (PVC) is used as a skin material, and a pattern E is selected as the second mold clamping state in order to prevent the skin material near the gate from being melted.

After grasping the conditions under which a good product can be formed at the trial driving stage before the actual operation, the following forming conditions are set. Injection conditions such as the injection condition of the first layer core material resin and the injection condition of the second layer intermediate material resin, the mold opening amount set value (Q1) in the pattern C in the first mold clamping state, and the mold clamping force load. Force setting value (P4) for setting, the mold opening amount setting value (Q2) which is the mold opening amount when the skin material is inserted into the mold, and the mold opening in the pattern E which is the second mold clamping state. The mold setting conditions such as the set amount (Q3), the mold clamping force set value (P6) for the mold clamping force load to be performed when injecting the second layer intermediate material resin, the cooling holding time T1 of the first layer core material resin, and The cooling holding conditions such as the cooling holding time T2 of the second layer intermediate material resin are input and set.

After the setting of the initial conditions is completed as described above, the molding operation in the actual operation is started.
The following procedure is performed as shown in FIG. (A) The mold opening amount set value (Q
The mold clamping operation is performed corresponding to 1). Mold opening sensor 65
After the detection signal reaches the set value, the position holding control is performed by controlling the oil pressure of the mold clamping cylinder 22 so as to maintain the set value (Q1). (B) Shut-off valve 3 of first injection unit 30A
1A is opened, and the molten resin of the first layer serving as the core material is injected and filled into the mold cavity. At this time, since the injection filling is performed in the mold open state, the pressure deviation of the resin in the mold cavity is eliminated, and a high-quality core molded body with little residual distortion and no deformation or warpage is obtained. By reducing the pressure of the resin in the mold cavity, high-speed injection filling becomes possible. As a result, the resin is injected and filled with a small decrease in temperature, and the quality of the core molded body is promoted. The completion of the injection filling of the molten resin of the first layer is determined by the timing control unit 63.
, The shut-off valve 31A of the first injection unit 30A is closed, the hydraulic pressure of the mold clamping cylinder 22 is controlled to apply the mold clamping force (P4), and the molding of the molten resin in the first layer is performed. Do.

(C) Simultaneously with the application of the mold clamping force (P4), the mold opening operation is performed based on the mold clamping conditions previously set by the mold clamping condition setting section 66. In addition, the mold opening operation is performed in accordance with the cooling and solidification state of the first layer molten resin, taking into consideration the adhesiveness with the second layer intermediate material resin, and immediately after completion of filling, a cooling holding time set at an arbitrary time. This is performed after the lapse of T1. This cooling holding time T
If 1 is too short, the shape of the first layer core resin will be insufficient. On the other hand, if the length is too long, the state of welding between the first layer core resin and the second layer intermediate material resin becomes insufficient, resulting in a decrease in strength.
The mold opening operation is performed in accordance with the mold opening amount set value (Q2) set by the mold clamping condition setting unit 66. After the detection signal of the mold opening sensor 65 reaches the set value, the position holding control is performed by controlling the oil pressure of the mold clamping cylinder 22 so as to maintain the set value (Q2). Next, between the movable mold in the mold open state and the first layer core resin molded body, a skin material carry-in device (not shown)
Insert and set the skin material. After the skin material is inserted and set, the mold clamping operation is performed in accordance with the mold opening amount set value (Q3) set by the mold clamping condition setting unit 66. After the detection signal of the mold opening sensor 65 reaches the set value (Q3),
The position holding control is performed by controlling the oil pressure of the mold clamping cylinder 22 so as to hold the set value (Q3).

(D) The shut-off valve 31B of the second injection unit 30B is opened to inject the second layer of molten resin as an intermediate material into the secondary space formed by the core molding and the movable mold. Fill. Here, since the second layer intermediate resin is injected and filled in a state where the mold is opened and held with the mold opening amount Q3, the resin pressure in the mold cavity is reduced and the tree finger pressure in the gate portion is suppressed to be low. Further, it is possible to prevent the skin material near the gate from being melted.

(E) After detecting the completion of the injection filling of the molten resin of the second layer by the timing control section 63, the shut-off valve 31B of the second injection unit 30B is closed, and
The mold clamping operation is performed based on the mold clamping conditions set in the mold clamping condition setting unit 66 previously. That is, the mold clamping force is applied and the mold is clamped and held by the mold clamping force of P6. Here, by applying a uniform compressive force to the resin from the mold clamping side corresponding to the cooling, solidification and shrinkage behavior of the resin, the pressure deviation and residual strain of the resin in the mold cavity caused during injection filling are reduced. As a result, deformation and warpage are eliminated, the degree of adhesion between the core molded body, the second layer molten resin and the skin material is enhanced, and the effect of the state of holding the mold open when the first layer molten resin is injected and filled is synergistic. As a result, an extremely high-quality multilayer molded product can be obtained.

The control of the mold clamping side and the injection side in the mold clamping process is performed, for example, at the same time as the start of the injection and filling of the first layer of the molten resin or the timer which is started simultaneously with the start of the injection and filling of the second layer of the molten resin. This is performed based on the 62 timeout signal. Here, the measurement start time (t1, t
2) The cooling holding time (T1, T2) is set in advance. That is, the measurement start times t1 and t2 are for measuring the first and second injection units in preparation for the next molding, and the cooling holding times T1 and T2 are the physical properties of the resin to be filled and the cooling of the mold. This is for calculating the resin cooling completion time from the capacity and the like, and for calculating the resin cooling time from the properties and the cooling capacity of the mold.

(F) After the cooling holding time T2 has elapsed, the mold is opened, and a molded product is taken out by a molded product removal device (not shown) to complete one molding cycle.

In addition to the above description, for example, when a foaming resin is used as the intermediate resin of the second layer, the second mold clamping state may be controlled in position by setting a multi-stage mold opening set value or a minute control. By adopting the mold opening control by setting the mold clamping force, the expansion ratio can be controlled. That is, the volume occupied by the second layer intermediate resin (foamable resin) can be controlled by controlling the mold opening amount at the time of completion of filling with respect to the mold opening amount at the start of injection filling of the second layer intermediate material resin. This makes it possible to control the expansion ratio. Further, as the skin material, a printing film, a raised cloth, or the like may be used, or the skin material may be attached to both sides or the whole surface.
Another resin layer may be provided in addition to the two-layer resin of the core material and the intermediate material.

[0023]

As described above, in the present invention,
The following excellent effects can be exhibited. (1) Surface decoration can be freely expressed by selecting and combining the material of each layer of the first layer core material resin, the second layer intermediate material resin, and the decorative skin material, and can be handled by the conventional multilayer molding method. It has become possible to produce multilayer molded products that have both softness and cushioning, and feel and texture that were not available. (2) Added value by decorating a high-quality surface without damage to the skin material and without deformation or warping by multi-stage control of the mold clamping force and mold opening amount and selection of molding conditions suitable for the molding resin and the skin material High quality molded products can be supplied efficiently and stably.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a resin multilayer molding apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of a resin multilayer molding process according to an embodiment of the present invention.

FIG. 3 is an operation explanatory diagram for explaining a molding operation according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed board 2 Movable board 3 Fixed mold 4 Movable mold 5 Cavity 10 Mold device 20 Mold clamping device 22 Mold clamping cylinder 30 Injection device 30A First injection unit 30B Second injection unit 31A Shut-off valve (First injection unit) 31B Shut-off valve (second injection unit) 60 Control device 61 Mold clamping control unit 62 Timer 63 Timing control unit 64 Injection control unit 65 Mold opening sensor 66 Mold clamping condition setting unit 67 Mold opening setting unit 68 Mold position Sensor 69 Mold clamping cylinder stroke sensor 70A, 70B, 70C Hydraulic control valve 80A, 80B, 80C Hydraulic supply source 100 Multilayer molding device P1, P2, P3, P4, P5, P6 Mold clamping force set value Q1, Q2, Q3 Mold opening Quantity setting value T1 T2 Cooling completion time t1, t2 Measurement start time

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 9:00

Claims (7)

[Claims] 1. A first layer core material molten resin serving as a core material is injected and filled into a mold space formed by a movable mold and a fixed mold in a preset first mold clamping state. After the filling is formed, the two molds are relatively separated from each other and are kept at a predetermined mold opening set value, and a skin material is interposed between the first layer filling and the mold, and subsequently, In a preset second mold clamping state, a second material serving as an intermediate material is formed in a space formed by the first layer filler and the skin material.
Injection-filling the layer intermediate material molten resin, then applying and releasing the mold clamping force, and laminating and fusing and integrating the first layer core material resin, the second layer intermediate material resin, and the skin material in this order. Molding method of resin. 2. The first mold clamping state applies a mold clamping force that does not cause the mold to open due to the resin pressure of the filled first layer core material molten resin until the mold filling is completed. Claim 1 retained
A multilayer molding method for the resin as described in the above. 3. The first mold clamping state is such that a first mold clamping force that allows the mold to open by the resin pressure of the filled first layer core material molten resin during injection filling is applied to the mold. 2. The method according to claim 1, wherein the pressure is increased to a second clamping force for shaping the first layer core material resin. 4. The first mold clamping state is to hold both molds at a predetermined mold opening set value during injection filling, and thereafter to shape the first layer core material resin. The method according to claim 1, wherein the applied mold clamping force is applied to the mold. 5. The mold clamping state according to claim 1, wherein in the second mold clamping state, a mold clamping force that allows the mold to open by the resin pressure of the filled second layer intermediate material molten resin is applied to the mold. Resin multi-layer molding method. 6. The method according to claim 1, wherein in the second mold clamping state, the two molds are separated from each other and held at a predetermined mold opening set value. 7. A multi-layer injection mechanism for injecting and filling a first layer and a second layer of molten resin into a mold space formed by a movable mold and a fixed mold, and interposing a skin material in the mold. A carry-in / out mechanism for carrying the multilayer molded article out of the mold, and a mold clamping force in first and second mold clamping states when the first and second layers of molten resin are injected and filled into the mold space. Is set in multiple stages or the mold opening amount is set in multiple stages, the mold opening amount set value when the skin material is interposed in the mold, and the mold clamping force or mold opening amount after injection filling of the second layer molten resin. A mold clamping condition setting unit for setting and inputting a quantity, a mold clamping control unit for controlling a mold clamping mechanism based on a signal from the mold clamping condition setting unit, and a mold clamping device operated by a signal from the mold clamping control unit. And a multilayer molding apparatus for a resin.