JPH11207776A - Method and device for resin multilayer molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture efficiently and stably a resin multilayer molded part of superior surface decoration performance provided with the soft feeling and cushioning properties as well as the touch feeling, quality feeling and the like. SOLUTION: First layer molten resin forming a core material is injection filled into a mold space formed of a movable mold and a fixed mold in the preset first mold clamped state, and then both molds are separated relatively and retained at the given mold opening amount set value, and a skin material is interposed between a first layer filler material and the molds. Successively second layer molten resin forming an intermediate material is injection filled into a space formed by the first layer filler material and the skin material in the preset second mold clamped state, and then at the point of time when the temperature monitor value reaches the preset temperature in a temperature zone representing the rubber-like elasticity of the skin decorative material, a clearance corresponding to the thickness of the skin material decorative layer is formed between the skin material and the molds and retained for the set time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a first-layer core material molten resin which is injected and filled into a mold to obtain a first-layer core material filling material, and then the second-layer intermediate material molten resin is filled into the first layer. The present invention relates to a multilayer molding method and a multilayer molding apparatus for a resin that is laminated on a surface of a layer core material filling material and also has a decorative skin material fused and integrated on a 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). After injecting and filling the first layer resin (core material) into the mold, and injecting the second layer resin (decorative material) with the part or entire surface of the mold receded or the mold clamping force reduced. In addition, an injection holding pressure 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. A skin material such as a raised cloth or a woven fabric is used to provide a feeling of touch and texture, but the skin material is damaged by the load of the high-temperature and high-pressure core material resin during molding (for example, With a blanket, it is difficult to maintain the original texture (feel and texture) of the skin material even after molding. (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. (3) As one of the multi-functional expression molded products for which demand is expected to increase in the future, high-quality multi-layer molded products having both softness and cushioning properties and feel and texture are required.
It is extremely difficult to cope with the current 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, After clamping a mold with a skin material having a decorative layer on the surface between a pair of opposing molds, the core material is formed in a mold cavity space formed by the skin material and the two molds. In a multi-layer molding method of a resin in which a molten resin is injected and filled in multiple layers and the skin material and the core material are integrally formed, the decorative layer of the skin material has a glass transition point at the time of injection of the second layer intermediate material resin. Select a material that is lower than the temperature of
After the first layer core material molten resin as a core material is injected and filled into the mold cavity space to form a first layer filling, the two molds are relatively separated from each other to set a predetermined mold opening amount. While maintaining the value, a skin material is interposed between the first-layer filling material and the mold, and then the first-layer filling material and the skin material are formed in a preset second mold clamping state. After the second layer intermediate material molten resin as an intermediate material is injected and filled into the space to be formed, the temperature monitor value reaches a preset temperature in a temperature range indicating the rubber-like elasticity of the skin material decorative layer set in advance. At this point, a gap was provided between the skin material and the mold according to the thickness of the skin material decoration layer, and the gap was maintained for a set time.

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 injection filling is completed. The mold was loaded and held. In the third invention, the first mold clamping state is a 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. Then, a second mold clamping force for forming the first layer core material resin is applied to the mold.

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 is provided. A mold clamping force intended to shape the resin was applied to the mold.
Furthermore, in the fifth invention, the second mold clamping state applies a mold clamping force that does not cause the mold to open due to the resin pressure of the filled second layer intermediate material molten resin until the injection filling is completed. We decided to load and hold.

In the sixth invention, the second mold clamping state is such that a first 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. Then, a second mold clamping force is applied to the mold for the purpose of shaping the resin of the second-layer intermediate material and fusing and integrating the skin material, the first-layer core material, and the second-layer intermediate material. I decided that. In the seventh invention, the second mold clamping state is such that the two dies are relatively separated from each other and held at a predetermined mold opening set value during injection filling, and thereafter, the second layer intermediate material resin is applied. Shape and skin material, first layer core material and second layer
A mold clamping force for the purpose of fusing and integrating the interlayer material was applied to the mold.

In the eighth invention, the temperature monitor value in the first invention is defined as the surface temperature of the skin decoration layer during molding. In a ninth aspect, the temperature monitor value in the first aspect is the surface temperature of the second layer intermediate material resin during molding.

In a tenth aspect, a multilayer injection mechanism for injection-filling a first layer core material and a second layer intermediate material molten resin into a mold cavity space formed by a movable mold and a fixed mold,
A carry-in / out mechanism for interposing a skin material in the mold and carrying out the multilayer molded product out of the mold, and a first and a second mechanism for injection-filling the first layer core material and the second layer intermediate material molten resin. 2
The mold clamping force in the mold clamping state is set in multiple stages or the mold opening amount is set in multiple stages, and the first mold opening amount setting value when the skin material is interposed in the mold, and the skin material decoration layer A mold clamping condition setting unit for setting and inputting a second mold opening set value of a gap between the skin material and the mold according to a thickness, and a temperature region indicating rubber-like elasticity of the skin decoration layer A temperature condition input unit for setting and inputting a temperature at which a mold clamping control state is switched in the temperature monitor unit, a temperature monitor unit for monitoring a surface temperature of a decorative material decoration layer surface or a second layer intermediate resin surface temperature during molding, and a temperature monitor unit. A comparison control unit that compares the signal with the set value of the temperature condition input unit, and issues a timing signal to the mold clamping control unit to switch from the second mold clamping state to the mold clamping state of the second mold opening set value; The mold opening amount detection unit that detects the pressure, the pressure detection unit that detects the mold clamping force, the comparison control unit and the mold clamping condition setting unit And configured to have a mold clamping control unit for controlling the mold clamping mechanism on the basis of the issue.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a material having a glass transition point lower than the temperature at the time of injection of a second layer resin (intermediate layer) is selected for a decorative layer of a skin material. After injection filling of the core layer), the mold is temporarily opened and the skin material (decorative layer)
Is inserted and set in the mold.
Subsequently, after injecting and filling the second layer resin (intermediate layer), the mold clamping force is applied, and the temperature monitor value of the detected temperature of the skin decoration layer indicates the rubber-like elasticity of the skin decoration layer. When the set temperature is reached, the load on the decorative layer of the skin material is removed, and a space is provided in the mold that secures the space where the damaged decorative layer can be elastically recovered. I do. By doing so, the skin material decorative layer damaged by external force during molding (load of the intermediate layer resin at high temperature and high pressure) is restored by the elastic force, and the original texture of the skin material is secured. Waiting for the cooling of the core layer / intermediate layer resin to complete and removing the molded product after opening the mold, the core layer / intermediate layer /
It is possible to efficiently and stably obtain a high-quality multilayer molded product in which the surface decoration layer is integrally fused and the original texture of the skin material is maintained.

Further, in the present invention, the material of each layer can be selected according to the quality and function required of the molded article, and the surface decoration performance can be freely imparted by combining these layers. Become. 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. (A texture and a texture) can be simultaneously provided with a soft feeling, a cushioning property, a touch feeling and a texture without the conventional heat-resistant and pressure-resistant protective layer laminating treatment. It is possible to efficiently and stably supply a skin-decorated molded product that was possible.

By controlling the mold clamping force or the amount of mold opening in multiple stages as required during the injection and filling of the first layer resin and the second layer resin, the flow rate and the resin pressure of the resin at the time of injection and filling are kept low. The pressure in the mold can be reduced and the injection filling time can be shortened. As a result, damage to the skin material during molding can be suppressed to a low level, so that the time required in the process of recovering the decoration layer from damage can be shortened, and the resin pressure in the mold can be made uniform by holding pressure from the mold clamping side. Thus, a molded article free from deformation and warpage can be obtained, and a high-quality molded article excellent in surface decoration performance can be obtained.

When the temperature monitor value is the temperature of the second layer intermediate material resin, the second layer intermediate material resin is retained even if the temperature of the skin decoration layer is cooled below the glass transition point. The heat-transfer effect from the skin material to the mold due to the heat quantity and the gap provided in the mold causes the skin decoration layer to be reheated to a temperature region showing rubber-like elasticity equal to or higher than the glass transition point. Thereby, the damaged part can be self-recovered by the rubber-like elastic force of the skin material decoration layer. In this case, since the load of the mold clamping force for the purpose of fusing and integrating the first layer core material resin, the second layer intermediate material resin, and the skin material and shaping can be continued for a longer time, deformation, warping, and uneven thickness can be achieved. , And a high quality molded product having excellent surface decoration performance can be efficiently and stably obtained.

[0014]

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 4 relate to an embodiment of the present invention,
1 is an overall configuration diagram of a resin multilayer molding apparatus, FIGS. 2 and 3 are flowcharts of a resin multilayer molding process, and FIG. 4 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 comprises 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. In this embodiment, the horizontal mold clamping system is used, but a rigid mold clamping system is also possible. The mold clamping device 20 includes the mold device 10.
Mold cylinder 2 that operates to open and close the molds 3 and 4 of the mold
The movable mold 4 is guided by a tie bar (not shown) with respect to the fixed mold 3 and moves forward and backward.

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. The control device 60 includes, as shown in FIG.
Mold clamping control section 62, injection control section 63, temperature condition input section 6
4, comparison control unit 65, temperature monitoring unit 66, temperature sensor 6
7, a mold opening detecting section 68, a mold position sensor 69, a pressure detecting section 70, a resin pressure sensor 71, a hydraulic control valve 80, a hydraulic supply source 90, and the like. The pressure information measured by the resin pressure sensor 71 disposed on the fixed mold 3 and the two molds 3 and 4
The position information of the mold position sensor 69 for detecting the opening amount of the mold is input to the mold clamping control unit 62, and an operation signal is given to the mold clamping cylinder 22 of the mold clamping device 20 via the hydraulic control valve 80A. In addition, 90 is a hydraulic supply source. The skin material decoration layer temperature information measured by the temperature sensor 67 (when the intermediate material resin temperature information is detected, the temperature sensor 67 is attached to the intermediate material resin side).
Is disposed) via the temperature monitor 66, via the temperature condition input 64 and the comparison controller 65.
2 are connected.

FIGS. 2 and 3 show a flowchart of the resin multi-layer molding process, and the outline thereof will be described below. The first mold clamping state has the following three patterns,
Select one of them.

Pattern A is a method in which the mold is clamped with 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. In addition to the pressure control for shaping the first layer resin by the load of the mold clamping force, the same method is used for the means (position control) for holding the mold at the set value of the mold clamping position that gives a compression (shaping) effect. Shape effects can be obtained. 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, similarly to the pattern B, the first layer resin can be formed by position control.

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 easy to flow, 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 three patterns, one of which is selected. Pattern D is a method in which the mold is clamped with a mold clamping force that does not generate burrs during the injection filling of the second layer resin, and this state is maintained until the injection filling is completed.
This pattern D is selected when a high-flow resin is used as the second-layer resin or when the mold is easily flowable. The pattern E is injection-filled in a state where the mold is clamped with a small mold-clamping force such that the mold is opened appropriately when the second layer resin is injected and filled. This is a method in which the mold clamping force is increased at an arbitrary point during the injection filling or at the completion of the injection filling to perform the shaping of the second layer resin and the fusion bonding of the skin material, the intermediate material, and the core material. 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 F is injected and filled with the second layer resin while holding the mold 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, and the shaping of the second layer resin and the fusion bonding of the skin material, the intermediate material, and the core material are performed. 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. In the patterns E and F, similarly to the pattern B, the shaping of the second layer resin and the fusion bonding of the skin material, the intermediate material, and the core material can be performed by the position control method.

The appropriate mold opening amount during injection filling in patterns C and F differs depending on the gate shape, mold structure, type of skin material and injection conditions, and the molten resin in the cavity does not leak even if the mold is opened. Such a mold structure is required. Based on the above, as a first-layer core material resin, a hard-flowable resin (for example, an ABS resin) or a second-layer intermediate material resin is selected from hard resin materials for the purpose of maintaining the shape and imparting strength of a molded product. P which has an elastomer from a soft resin material for the purpose of imparting a soft feeling and cushioning property and a brushed layer from a decorative material for the purpose of imparting a feeling of touch and luxury as a decorative layer
The molding operation in actual operation will be described by taking a laminated molded article made of an ET skin material as an example. The most important thing for the present invention lies in the selection of the material of the skin decoration layer. That is, in order to use the damage recovery phenomenon of the decorative layer due to the elastic force, the glass transition temperature of the decorative layer (T _g = 7 in the case of PET)
(0 to 80 ° C.) is lower than the temperature at the time of injection of the intermediate resin (in the case of an elastomer, usually heated to about 200 to 220 ° C.). Since a resin having poor fluidity is used as the core material, the first mold clamping state is the pattern C
Select A PET skin material having a raised layer is used as a decorating layer, and a pattern F is selected as the second mold clamping state in order to prevent the skin material near the gate from being melted.

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 set value (Q1) in the pattern C in the first mold clamping state, and the mold clamping Switching timing from position control to mold clamping force control (R2), set mold clamping force (P4), mold opening amount setting value (Q2) which is the mold opening amount when the skin material is inserted into the mold, and the second. The mold closing amount (Q3) in the pattern F in the mold clamping state, the switching timing (R4) from the mold clamping position control to the mold clamping force control, the mold clamping conditions such as the set mold clamping force (P8), and the skin. A mold clamping condition such as a mold opening set value (Q4) in the damage recovery process of the material decoration layer and a cooling holding condition such as a cooling holding time of the first layer core material resin are input and set.

After the setting of the initial conditions is completed as described above, the molding operation of the actual operation is started.
And FIG. 3 and FIG. (A) The mold opening amount set value (Q
The mold clamping operation is performed corresponding to 1). Mold opening sensor 69
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 mold clamping operation is started by the timing signal (R2) set by the mold clamping condition setting unit 61, and the first layer resin is shaped by the set mold clamping force (P4) load. Note that the timing signal (R2) is set at an arbitrary point during the injection filling operation, such as the elapsed time from the start of injection, the stroke of the injection cylinder, and the like. Therefore, when the set mold clamping force (P4) is applied, the shutoff valve 31A of the first injection unit 30A is closed (to prevent backflow of the filled resin).

(C) The mold opening operation is performed based on the mold clamping conditions set by the mold clamping condition setting section 61 previously. 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 done after the lapse.
If the cooling holding time is too short, the shaping of the first layer core resin becomes insufficient. On the other hand, if it is too long, the state of fusion 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 61. After the detection signal of the mold opening sensor 69 reaches the set value, the set value (Q
The position holding control is performed by controlling the oil pressure of the mold clamping cylinder 22 so as to hold 2). Next, a skin material is inserted and set between the movable mold in the mold open state and the first layer core resin molded body by a skin material carrying-in device (not shown). In addition, as the form of the skin material, a material roughly preformed into a sheet shape or a mold shape is used. As a method of setting in a mold, a suitable method is used from among vacuum suction, needle sticking, core pressing and the like.
After inserting and setting the skin material, the mold clamping condition setting unit 6
The mold clamping operation is performed in accordance with the mold opening amount set value (Q3) set in 1. The detection signal of the mold opening sensor 69 is set to the set value (Q
After reaching 3), the position holding control is performed by controlling the oil pressure of the mold clamping cylinder 22 so as to maintain the set value (Q3).

(D) By opening the shut-off valve 31B of the second injection unit 30B, the second layer molten resin as an intermediate material is formed by the core molding and the movable mold / skin material.
The next space is injected and filled. Here, since the second layer intermediate resin is injected and filled in a state where the mold is opened and held at the mold opening amount Q3, the resin pressure in the gate portion is suppressed to be low while the resin pressure in the mold cavity is reduced. Therefore, it is possible to prevent the erosion of the skin material near the gate portion.

(E) According to the timing signal (R4) set by the mold clamping condition setting section 61, the mold clamping operation is started to apply the set mold clamping force (P8). The timing signal (R
4) can be set at any time during the injection filling as in the case of R2. Therefore,
Also in this case, the shutoff valve 31B of the second injection unit 30B is closed. The load of the set mold clamping force (P8) is performed for the purpose of shaping the second layer molten resin (intermediate material) and fusing and integrating the skin material, the intermediate material, and the core material (shaping of the multilayer molded body). Process). The skin material is heated by the calorific value of the intermediate resin at the same time as the injection filling of the intermediate resin,
At the same time as the start of the application of the mold clamping force (P8), the skin material is damaged by the application of the high-temperature and high-pressure intermediate resin. If the mold clamping force holding time is long, the shapeability of the multilayer molded body is improved,
The degree of damage of the skin decoration layer increases. Conversely, when the holding time is shortened, damage to the decorative layer of the skin material is reduced, but the shapeability of the multilayer molded body is deteriorated. That is, the prevention of damage to the skin material and the improvement of the shapeability of the multilayer molded article are contradictory objects to be controlled, and it has been extremely difficult to balance this.

In the present invention, a material whose glass transition point is lower than the temperature at the time of injection of the intermediate resin of the second layer is selected as the decorative layer of the skin material, and the load of the set mold clamping force (P8) is reduced. At the same time as the start, the temperature of the skin decoration layer is monitored by the temperature sensor 67, and the temperature is set within a temperature range (temperature above the glass transition point) where the skin decoration layer exhibits rubber-like elasticity during the shaping process of the multilayer molded body. When the monitor temperature reaches the set temperature M, the mold clamping force is removed and the set mold opening (Q4) is maintained for the set time (T) to decorate the skin material damaged during molding. The layer is recovered by the elastic force, and the adoption of a molding control method for ensuring the original texture of the skin material balances the shapeability of the multilayer molded body and the prevention of damage to the skin material. Here, the set temperature (M) is such that the cooling and solidification of the intermediate resin and the fusion and integration of the skin material, the intermediate material and the core material (that is, the shaping properties of the multilayer molded body) sufficiently proceed, and the decoration of the skin material Within the temperature range where the layer exhibits rubber-like elasticity, it is set as a temperature condition for recovering damage to the decorative layer of the skin material received during molding. In addition, the set mold opening amount (Q4) is such that a gap between the mold and the skin material is provided to be equal to or greater than the thickness of the skin material including the skin decoration layer, and the recovery space due to the elastic force of the skin decoration layer is provided. It is set for the purpose of securing and securing a temperature holding time showing rubber-like elasticity by interrupting heat transfer between the mold and the decorative layer. Setting time (T) is the time recovery by the elastic force (i.e., the range of cooling time from the set temperature (M) to the glass transition temperature T _g), the cooling process of the intermediate material (or core material) in the conventional molding Since it was confirmed by experiments that the time was within the set time range, the cooling time of the intermediate resin was set to be the same. When the temperature monitor value is the intermediate material resin temperature, even if the skin material decoration layer temperature is T
Even if it is cooled below _g , the set mold opening (Q4)
The heat of the heat transfer blocking effect and the intermediate material resin by, the skin material decorative layer is re-heated above T _g, the recovery state of a rubber-like elastic is achieved. In this case, since the load time of the set mold clamping force (P8) can be continued for a long time, the shapeability of the multilayer molded body is greatly improved.

(F) After the set time (T) has elapsed, the mold is opened,
Take out the molded product using a molded product removal device (not shown)
Complete one molding cycle. In addition to the above description, the command of the timing for switching the mold clamping conditions to the set mold opening (Q4) by detecting the set temperature (M) is also issued, for example, from the start of injection of the intermediate resin to the set temperature (M). The arrival time can be measured by several molding trials, and the elapsed time of the measurement result can be used as a switching timing command. In this case, control can be simplified. In addition, although the shaping of the core material resin and the shaping of the multilayer molded body have been performed under the load of the mold clamping force from the mold clamping side (patterns B and C and patterns E and F), the holding pressure from the injection side is reduced. The same effect can be obtained even when used in combination with a load or when only the holding pressure on the injection side is used. However, in this case, the effect of the uniform pressure-holding action from the mold clamping side cannot be expected.

Further, for example, as the second layer intermediate resin,
When a foaming resin is used, the expansion ratio can be controlled by adopting the position control based on the multi-stage mold opening amount setting value and the mold opening control by setting the minute mold clamping force in the second mold clamping state. . In this case, the volume occupied by the second layer intermediate material 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. Thus, the expansion ratio can be controlled. In addition, as the skin material, a printed film, a leather-like sheet, or the like can be used. 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.

[0031]

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) Decorating a high quality surface without damage to the skin material by utilizing the recovery behavior due to rubber-like elasticity, multi-stage control of mold clamping force and mold opening, and selection of molding conditions suitable for molding resin and skin material The obtained high value-added molded product can be efficiently and stably obtained. (3) Due to the uniform pressure-holding action from the mold-clamping surface over the entire surface of the mold cavity and the load of sufficient mold-clamping force, there is no deformation or warpage, and completely multilayered core resin, intermediate resin, and skin material. A very good skin material insert molded product that is integrated by fusion can be obtained.

[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 the first half of a resin multilayer molding process according to an embodiment of the present invention.

FIG. 3 is a flowchart of the second half of the resin multilayer molding step according to the embodiment of the present invention.

FIG. 4 is an operation explanatory diagram for explaining a molding operation according to the embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 fixed platen 2 movable platen 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 Controller 61 Mold clamping condition setting unit 62 Mold clamping control unit 63 Injection control unit 64 Temperature condition input unit 65 Comparison control unit 66 Temperature monitor unit 67 Temperature sensor 68 Mold opening detection Part 69 Mold position sensor 70 Pressure detection part 71 Resin pressure sensor 80A, 80B, 80C Hydraulic control valve 90A, 90B, 90C Hydraulic supply source 100 Multilayer molding device M Set temperature P1, P2, P3, P4, P5, P6, P7 , P8 Mold clamping force setting Q1, Q2, Q3, Q4 Mold opening setting R1, R2, R3, R4 Timing set value T set time

Claims (10)

[Claims] After a mold is clamped by interposing a skin material having a decorative layer on the surface between a pair of opposed molds, the mold is closed in a mold cavity space formed by the skin material and the two molds. In a multilayer molding method of resin in which a molten resin serving as a core material is injection-filled in multiple layers and the skin material and the core material are integrally molded, the decorative layer of the skin material has a glass transition point of a second layer intermediate material. A material lower than the temperature at the time of injection of the resin is selected, and a first layer core material melted resin serving as a core material is injected and filled into the mold cavity space in a first mold clamping state set in advance to form a first layer. After the filling is formed, the two dies 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 dies, Subsequently, in a preset second mold clamping state, the intermediate material becomes an intermediate material in a space formed by the first layer filling and the skin material. After injecting and filling the two-layer intermediate material molten resin, when the temperature monitor value reaches a preset temperature within the temperature range showing the rubber-like elasticity of the skin material decoration layer, the gap between the skin material and the mold is reached. A multi-layer molding method for a resin, wherein a gap corresponding to the thickness of the skin material decoration layer is provided for a predetermined time. 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 to apply a first mold clamping force to the mold to allow the mold to open by the resin pressure of the filled first layer core material molten resin during injection filling. 2. The method according to claim 1, wherein the mold is loaded, and then the mold is subjected 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 second mold clamping state is such that a mold clamping force that does not cause the mold to open due to the resin pressure of the filled second layer intermediate material molten resin is applied to and held by the mold until the injection filling is completed. A method for multilayer molding of a resin according to claim 1. 6. The second mold clamping state is to apply a first 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 thereafter to apply the first mold clamping force to the mold. Wherein a second mold clamping force is applied to the mold for the purpose of shaping the second layer intermediate material resin and fusing and integrating the skin material, the first layer core material and the second layer intermediate material. A multilayer molding method for the resin as described in the above. 7. A second mold-clamped state holds the two molds at a predetermined mold-opening-amount set value during injection filling while keeping the two molds relatively separated from each other.
2. The mold according to claim 1, wherein a mold clamping force for shaping the resin of the second layer intermediate material and fusing and integrating the skin material, the core material of the first layer and the intermediate material of the second layer is thereafter applied. Resin multi-layer molding method. 8. The resin multilayer molding method according to claim 1, wherein the temperature monitor value according to claim 1 is a surface temperature of a skin decoration layer during molding. 9. The method according to claim 1, wherein the temperature monitor value according to claim 1 is a surface temperature of the second layer intermediate material resin during molding. 10. A multilayer injection mechanism for injecting and filling a first layer core material and a second layer intermediate material molten resin into a mold cavity space formed by a movable mold and a fixed mold, and a skin material formed by the mold. A carry-in / out mechanism for interposing the multilayer molded product out of the mold and a mold in the first and second mold-clamped states when the first layer core material and the second layer intermediate material molten resin are injected and filled. The clamping force is set in multiple stages or the mold opening amount is set in multiple stages, and the first mold opening amount set value when the skin material is interposed in the mold and the thickness of the skin material decoration layer are set. A mold clamping condition setting unit for setting and inputting a second mold opening amount set value as a gap between the skin material and the mold; and a mold clamping control in a temperature region indicating rubber-like elasticity of the skin material decorative layer. A temperature condition input section for setting and inputting a temperature at which the state is switched, and a surface temperature of the surface decoration layer during molding or a second layer intermediate material A temperature monitor for monitoring the resin surface temperature, and comparing the signal of the temperature monitor with the set value of the temperature condition input section to the mold clamping control section for clamping the second mold opening set value from the second mold clamping state. A comparison control unit that issues a timing signal for switching to a state, a mold opening amount detection unit that detects a mold opening amount, a pressure detection unit that detects a mold clamping force, and a mold based on signals from a comparison control unit and a mold clamping condition setting unit. A multi-layer resin molding apparatus having a mold clamping control section for controlling a clamping mechanism.