JP3646503B2 - Multilayer molding method and apparatus for resin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, after setting the skin material in the mold, the first molten resin is injected and filled, and then the second molten resin is injected and filled, or after the second molten resin is injected and filled, the mold is once opened. The outer skin material is set, and then the first molten resin is injected and filled, and the outer skin material, the first molten resin, and the second molten resin are fused and integrated, so that the surface of the resin having a decorative property is obtained. The present invention relates to a resin multilayer molding method and multilayer molding apparatus for obtaining a multilayer molded article.
[0002]
[Prior art]
In recent years, more and more added value is required for resin molded parts used in automobiles, home appliances, building materials and the like. Along with the demand for added value such as feel and texture as well as softness and cushioning properties, there is an increasing demand for cost reduction by reducing the number of molding processes. In order to cope with these, conventionally, the following multilayer molding has been carried out. That is,
(1) Insert and set the skin material (decorative material) in the mold and inject and fill the core material in the mold-clamped or mold-opened state, and then apply the injection holding pressure or mold-clamping force and apply the core material. Cool down. By waiting for the completion of cooling and removing the molded product after opening the mold, a surface decorative molded product is obtained in which the skin material (decorative material) is fused and integrated on the surface of the core resin molded product ( Skin material insert molding).
(2) The first layer resin (core material) is injected and filled into the mold, and the second layer resin (decorative material) is placed in a state where the mold is partially or entirely retracted or the clamping force is reduced. After injection filling, the mold is advanced or a clamping force is applied and the filling resin is cooled. By waiting for the completion of cooling and taking out the molded product after opening the mold, a surface decorative molded product in which the decorative resin is laminated and integrated on the surface of the core material resin is obtained (sandwich molding).
[0003]
[Problems to be solved by the invention]
However, such a conventional method has the following problems.
(1) In the case of skin material insert molding, a skin material with a foam layer laminated on the back surface (core material resin side) is used to provide a soft feeling and cushioning properties. The foamed layer is easily melted away by the material resin, and the soft feeling and cushioning properties 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, a feeling of touch and texture are often required, but it is not possible to give a feeling of touch and texture only with a molding resin. Brushed or woven fabrics are ideal for decorating materials as a way to give a feeling of touch and texture, and conventional sandwich molding could not be used.
When a soft feeling, cushioning property, touch feeling and texture are required at the same time, it has been difficult to cope with the conventional molding method.
[0004]
[Means for Solving the Problems]
In order to solve the above-described problems, in the present invention, in the first invention, after the mold is clamped by interposing a skin material having a decorative layer on the surface between a pair of opposed molds, the skin A first molten resin is injected and filled into a mold cavity space formed by the material and the two molds to laminate the skin material and the first molten resin to form a first resin layer, and subsequently the first resin. A second molten resin is injected and filled into a mold cavity space formed by a layer and a mold to form a second resin layer, and a skin material, a first resin layer, and the second resin layer are sequentially stacked. After heating, the skin material decoration layer is heated to a set temperature set within the temperature range showing the rubbery elasticity of the skin material decoration layer using a heating means, and a predetermined amount is provided between the skin material and the mold. A mold opening amount was provided and held for a predetermined set time.
In the second invention, after the second molten resin is injected and filled into a mold cavity space formed by a pair of opposing molds to form the second resin layer, the two molds are relatively moved. And the mold is clamped with a skin material interposed between the second resin layer and the mold, and then the first molten resin is placed in the mold cavity space between the second resin layer and the skin material. After the injection filling, the skin material, the first resin layer, and the second resin layer are sequentially laminated and molded, and then the set temperature set within the temperature range showing the rubber-like elasticity of the skin material decoration layer using the heating means In addition to heating the skin material decoration layer, a predetermined mold opening amount is provided between the skin material and the mold, and the predetermined set time is maintained.
Furthermore, in the third invention, a multilayer injection mechanism that injects and fills the first molten resin and the second molten resin, an injection control unit that controls the multilayer injection mechanism, a skin material is set in the mold, and a multilayer molded product The temperature condition setting unit that inputs and sets the temperature at which the skin material decoration layer is heated within the temperature range showing the rubbery elasticity of the skin material decoration layer, and the skin material decoration A temperature monitoring unit for monitoring the temperature of the layer, heating means for heating the skin material decoration layer by comparing a signal of the temperature monitoring unit and a set value of the temperature condition setting unit, and a first molten resin and a second molten resin The mold clamping condition setting section for setting the mold opening condition value and mold opening holding time of the mold clamping operation linked with the heating means and the setting value of the mold clamping condition setting section A resin multi-layer molding device having a mold clamping control unit for controlling the clamping mechanism. .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
After the skin material is set in the mold and clamped, the first molten resin (intermediate material) is injected and filled. Subsequently, the second molten resin (core material) is injected and filled into a mold cavity space formed by the first resin layer (intermediate layer) and the mold. Alternatively, after the second molten resin (core material) is first injected and filled, the mold is opened and the skin material is set in the mold. After the mold clamping, the first molten resin (intermediate material) is injected and filled into the mold cavity space formed by the second resin layer (core layer) and the mold, and the skin material, the first resin layer, and the first Two resin layers are sequentially laminated. As a result, it is possible to freely impart surface decorating properties by selecting and combining the materials of each layer.
For example, hard resin is used for the core material to maintain the shape and strength of the molded product, foam resin and soft resin are used for the intermediate material to provide softness and cushioning, and the skin decoration layer has a touch and high-quality feel. By using brushed fabric, woven fabric, or laser sheet for the purpose of imparting softness, surface treatment that combines softness, cushioning, hand feeling, and luxury without the conventional heat treatment / lamination surface treatment of the laminate A decorative molded product (which was impossible with the conventional molding method) can be obtained efficiently and stably.
[0006]
Furthermore, when the fusion integration and shaping of the skin material / intermediate material / core material is completed, the skin is brought to the set temperature set within the temperature range showing the rubber-like elasticity of the skin material decoration layer using a heating means. Heating the decorative layer and holding the specified space with a gap between the skin material and the mold to secure the recovery space, the skin was deformed (damaged) by external force during molding. The material decoration layer is self-recovered by the elastic force, and the original texture of the skin material is restored.
This makes it possible to solve the conflicting control factors of fusing and shaping the skin material, intermediate material, and core material and preventing damage to the skin material at the same time and in a stable manner. A multi-layer process is not required, and a high-quality multilayer molded product having excellent surface decoration performance over the entire molded product can be obtained efficiently and stably.
[0007]
Furthermore, when foamed resin is used for the purpose of imparting a soft feeling and cushioning to the intermediate material, it is possible to control foaming of the foamed resin at the same time by heat treatment for restoring the elasticity of the skinned decorative layer. Three types of molding, multilayer molding of resin and foam molding can be achieved by a series of molding processes, and an extremely high quality and multifunctional multilayer molded body can be obtained efficiently and stably.
[0008]
【Example】
Details of embodiments of the present invention will be described below with reference to the drawings. 1 to 5 relate to an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a resin multilayer molding apparatus, FIG. 2 is a flowchart of a resin multilayer molding process according to an embodiment relating to claim 1 of the present invention, FIG. 3 is a flowchart of a resin multilayer molding process according to an embodiment relating to claim 2 of the present invention, and FIGS. 4 to 5 are explanatory views of the heating means of the present invention.
[0009]
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, a multilayer injection mechanism 30, a control apparatus 60, and an unillustrated skin material and molded article carry-in / out apparatus. The
The mold apparatus 10 includes a fixed mold 3 attached to the fixed platen 1 and a movable mold 4 attached to the movable platen 2, and the movable platen 2 and the movable mold 4 are mold clamping cylinders of the mold clamping device 20. 22 is configured to be able to move forward and backward.
The mold clamping apparatus 20 includes a mold clamping cylinder 22 that operates to open and close the molds 3 and 4 of the mold apparatus 10, and the movable mold 4 is a tie bar (not shown) with respect to the fixed mold 3. Go forward and backward as guided by.
[0010]
The multilayer injection mechanism 30 includes a first injection unit 30A for supplying a first molten resin (intermediate material) into the cavity 5 and a second injection unit 30B for supplying a second molten resin (core material) into the cavity 5. These are connected to the three-way valve 31 via a nozzle / resin passage. Further, the three-way valve 31 communicates with the cavity 5.
[0011]
On the other hand, as shown in FIG. 1, the control device 60 includes a temperature monitor unit 61 that detects the surface temperature of the skin material decoration layer, a temperature condition setting unit 62, a heating means control unit 63, a mold clamping control unit 64, and injection control. It comprises a part 65, a mold clamping condition setting part 66, and the like.
The mold clamping control unit 64 is connected to the heating means control unit 63, the injection control unit 65, and the mold clamping condition setting unit 66, and the heating means control unit 63 is connected to the temperature monitor unit 61 and the temperature condition setting unit 62. .
In this embodiment, an injection molding machine having a direct pressure type clamping device is used. However, an injection molding machine of a toggle clamping device, an injection molding machine of a vertical type, or an injection having an electric clamping device. A molding machine may be used.
[0012]
FIG. 2 is a flowchart of a resin multilayer molding process according to Embodiment 1 of the present invention, and FIG. 3 is a flowchart of a resin multilayer molding process according to Embodiment 2 of the present invention. 5 is an explanatory view of the heating means of the present invention, and its outline and operation method will be described below.
[0013]
Example 1
(A) With the molds 3 and 4 of the mold apparatus 10 being opened, the skin material S is set and held at a predetermined position on the mold cavity surface using means such as a vacuum suction method or a needle stick method. . As the skin material S, a material having a decoration layer suitable for the decoration characteristics required for the decoration layer exhibiting rubber-like elastic behavior is used. In addition, if necessary, for example, it is made of a resin of the same type and the same type as the intermediate material resin, which serves to prevent the intermediate material molten resin from exuding on the surface side and to promote fusion integration with the intermediate material resin. Laminated sheets on the back of the decorative layer, cushioned layers for the purpose of creating a soft feeling, multilayered skin materials and printed films with colored layers and adhesive layers for other purposes It can also be used as a skin material. In the present embodiment, a sheet-like skin material is used, but a material that has been pre-formed into a three-dimensional molded product shape may be used as the skin material. In this embodiment, the skin material is bonded only to one surface, but the skin material may be bonded to both surfaces of the core material resin.
[0014]
(2) The first molten resin (intermediate material) is injected and filled under a preset clamping condition, and a holding pressure is applied. When injecting and filling the intermediate material, an appropriate mold clamping control pattern is selected and adopted according to the type and combination of the skin material and the intermediate material, the product shape, and the like.
For example, if the filling conditions for the intermediate material resin are poor (low flow resin, mold cavity is complicated / thin wall shape), the intermediate material resin is injected and filled in a state where the mold is kept open at a predetermined mold opening position. A mold clamping control pattern is adopted in which a mold clamping force is applied at the time of completion of injection or at an arbitrary time during injection and the process proceeds to a pressure holding process. In this case, the flow of the mold cavity can be expanded by holding the mold open, the air and gas can be removed from the gap between the two molds, and the skin decoration layer can be prevented from being damaged (especially the gate). Demonstrate.
[0015]
(3) The second molten resin (core material) is subsequently injected and filled into the first resin layer and the cavity space of the mold, and the holding pressure is applied. Again, as in the case of injection filling with the first molten resin, an appropriate mold clamping control pattern is selected and adopted depending on the type / combination of the skin material, intermediate material, and core material, product shape, and the like.
The timing of starting the injection of the core material resin needs to be able to be fused and integrated with the intermediate material when the core material is injected and filled, and can be set by, for example, a time-out signal (t1) of a timer that starts when the injection of the intermediate material starts .
[0016]
(4) The skin material decoration layer is damaged by receiving a higher load than the molten resin in a high temperature / high pressure state simultaneously with the start of injection filling of the intermediate resin, and the degree of damage in the pressure holding process after the injection filling of the core resin It becomes a peak. From the viewpoint of preventing damage to the skin decoration layer, we want to reduce the applied external force (reduce the holding pressure and shorten the holding time), but fuse and integrate the skin material, intermediate material and core material. From the viewpoint of body shaping, it is desirable to increase the holding pressure and holding time. Although it is extremely difficult to achieve these contradictory control factors at the same time in one molding process, in the present invention, the damage prevention of the skin material decoration layer is performed in the next process (micro mold opening process after completion of pressure holding). Therefore, in this pressure holding step, it is possible to mainly perform welding integration and shaping of the skin material, intermediate material, and core material.
[0017]
(5) After completion of the pressure holding step, the skin material decoration layer is heated directly or indirectly using, for example, a heating means incorporated in the mold (see FIGS. 4 and 5).
The heating means incorporated in the mold is, for example, a mold cavity formed by an energized heating element disposed inside the mold along the shape of the mold cavity of the skin material decoration layer with the mold closed. It heats and heats a skin material decoration layer (refer FIG. 4). When the temperature of the skin material decoration layer is detected simultaneously with the heating, and the temperature of the skin material decoration layer reaches a set temperature (preset within a temperature region indicating the rubbery elasticity of the decoration layer) (M) The mold is kept open for the set time (t2) at the set mold opening value (T) (see FIG. 5). It should be noted that heating may be continued during mold opening or may be stopped if necessary. In addition, the skin material decoration layer is heated (in this case, using radiant heat due to mold cavity heating) in a state (FIG. 5) in which the mold is kept open at a preset mold opening value (T) (set temperature (M)). After reaching, the set time (t2) may be held, or the mold opening holding operation and the heating operation may be performed simultaneously.
[0018]
In addition to the above heating means, for example, heating means inside the mold such as heating of the mold by circulating the heating medium, thin film heating with an energized heating thin film coated on the cavity surface, and die heating using induction heat generation due to magnetism or high frequency. Heating method with heater, method of heating by inserting external heating means such as heater, hot air blowout, halogen heating irradiation etc. into the mold, direct induction by mixing induction heating material into the skin decoration layer Heating means for generating heat can be used alone or in combination.
[0019]
The set temperature (M) is a temperature condition for recovering the damage of the skin material decoration layer received during molding, and within the temperature range where the skin material decoration layer exhibits rubber-like elasticity (temperature above the glass transition point Tg). Set. Set mold opening (T) is the gap between the mold and the skin material equal to or greater than the thickness of the skin material including the skin material decoration layer in order to secure a self-healing space by the elastic force of the skin material decoration layer Alternatively, the gap is set by adding a space in which the heating means can be inserted. The set time (t2) is a time required for self-recovery by the rubber-like elasticity of the skin material decoration layer, and can be set by a time-out signal of a timer that starts when the set temperature (M) is reached by the heating means, for example. it can.
[0020]
(6) After the set time (t2) has elapsed, the mold opening operation is performed, the molded product is taken out, and one cycle is completed.
[0021]
Example 2
(1) In the same manner as in Example 1, the second molten resin (core material) is injected and filled under preset mold clamping conditions, and a holding pressure is applied. When injecting and filling the core material, an appropriate mold clamping control pattern is selected and adopted depending on the type of core material and product shape.
(2) The mold is held open at a predetermined mold opening position, the skin material is set in the mold opposite to the second resin layer, and after the mold is clamped, the second resin layer The first molten resin (intermediate material) is injected and filled into the gap between the mold and the holding pressure is applied. Again, as in the first embodiment, an appropriate mold clamping control pattern is selected and adopted in advance depending on the type / combination of the skin material, intermediate material, and core material, the product shape, and the like. The combination of the skin material and the skin material / intermediate material / core material is the same as in the first embodiment.
The injection start timing of the intermediate material resin is such that when the intermediate material is injected and filled, the core material can be fusion-integrated and the skin material can be fusion-integrated. For example, a timer that starts when the core material starts to be injected Set by timeout signal (t3).
Similar to the first embodiment, in this pressure holding process, the skin material, the intermediate material, and the core material are mainly fused and shaped.
[0022]
(3) After completion of the pressure-holding step, the skin decoration layer is heated directly or indirectly using, for example, a heating means incorporated in the mold as in Example 1 (see FIG. 4). The temperature of the skin material decoration layer is detected, and when the temperature of the skin material decoration layer reaches a set temperature (preset within a temperature region indicating the rubbery elasticity of the decoration layer) (M), the setting type The mold is held open for a set time (t2) with the opening amount (T) (see FIG. 5).
(4) After the set time (t2) has elapsed, the mold opening operation is performed to take out the molded product, thereby completing one molding cycle.
[0023]
In this way, after the pressure holding process is completed (the fusion integration of the skin material and the intermediate material resin and the shaping of the intermediate material and the core material resin are completed), the skin material decoration layer is heated using heating means. Then, at a set temperature (M) in the temperature range showing rubbery elasticity, by giving a gap between the mold of the set mold opening amount (T) and the skin material decorating layer, and holding the set time (t2), The skin material decoration layer deformed (damaged) during molding is self-recovered by rubber-like elasticity, and as a result, the original texture of the skin material is secured even after molding. This makes it possible to solve the conflicting control factors of the fusion and integration of the skin material, the intermediate material, and the core material resin, and the prevention of damage to the skin material simultaneously and stably, and the subsequent process and skin for recovery from damage. Eliminates the need for multi-layer processing of materials, and efficiently stabilizes multi-layer molded products of high-quality resin with excellent surface decoration performance on the entire surface of the molded product that achieves both softness, cushioning, touch and luxury. Can be obtained.
[0024]
Furthermore, as an incidental effect of the present invention, a great effect is exhibited when a foamed resin is used for the purpose of imparting a soft feeling and cushioning property to the intermediate material. In other words, the heat treatment for restoring the elasticity of the skin material decoration layer can control the foaming degree of the foamed resin at the same time, so a series of molding processes of skin material insert molding, resin multilayer molding and foam molding. Can be achieved. In this case, in the heat treatment step, the expansion ratio of the foamed resin can be accurately controlled by performing mold opening and holding with a predetermined mold opening amount by controlling the mold clamping side. It is also possible to perform control so that a predetermined mold opening amount is obtained by mold clamping force control.
[0025]
In addition to the above, for example, application to multilayer molded products in which the core material resin is injected and filled in the intermediate material resin layer, pasting the skin material on both sides instead of one side, changing the combination of the core material and the intermediate material, etc. The third and fourth layers may be multilayered.
[0026]
【The invention's effect】
As described above, according to the method of the present invention, the following excellent effects are achieved.
(1) Surface decoration can be freely expressed by selecting and combining the materials of the core layer, intermediate layer, and skin decoration layer, which can flexibly meet a wide range of requirements for surface decoration molded products. It becomes possible, and a high-quality surface decoration molded product can be supplied stably and efficiently.
(2) A multilayer molded product of resin that is surface-decorated with a skin material having a very excellent surface decoration performance without damaging the original texture of the skin material due to deformation (damage) of the skin material decoration layer during molding. It can be supplied efficiently and stably.
(3) Especially when foamed resin is used for the intermediate layer, the foaming degree control of the foamed resin and the prevention of damage to the skin material can be achieved at the same time in a series of molding processes. Cost reduction and quality improvement by shortening the molding process Can be achieved.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a resin multilayer molding apparatus used in the present invention.
FIG. 2 is a flowchart of a resin multilayer molding process according to Example 1 of the present invention.
FIG. 3 is a flowchart of a resin multilayer molding process according to Example 2 of the present invention.
FIG. 4 is an explanatory diagram of the heating means of the present invention.
FIG. 5 is an explanatory diagram of the heating means of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixed platen 2 Movable platen 3 Fixed metal mold 4 Movable metal mold 5 Mold cavity 10 Mold apparatus 20 Clamping apparatus 22 Clamping cylinder 30 Multilayer injection mechanism 30A 1st injection unit (for 1st molten resin)
30B Second injection unit (for second molten resin)
31 Three-way valve 60 Control device 61 Temperature monitoring unit 62 Temperature condition setting unit 63 Heating means control unit 64 Mold clamping control unit 65 Injection control unit 66 Mold clamping condition setting unit 100 Multi-layer molding apparatus S Skin material M Set temperature T Set mold opening t1, t2, t3 set time

Claims (3)

After clamping the surface having a decorative layer on the surface between a pair of opposing molds, the first molten resin is placed in the mold cavity space formed by the skin material and both molds. The first resin layer is formed by laminating the skin material and the first molten resin by injection filling, and then the second molten resin is injected and filled into the mold cavity space formed by the first resin layer and the mold. After forming the second resin layer and sequentially laminating the skin material, the first resin layer, and the second resin layer,
While heating the skin material decoration layer to a set temperature set within the temperature range showing the rubbery elasticity of the skin material decoration layer using a heating means, a predetermined mold opening amount is provided between the skin material and the mold. A resin multilayer molding method characterized by being provided and held for a predetermined set time After the second molten resin is injected and filled into a mold cavity space formed by a pair of opposing molds, a second resin layer is formed, and then the two molds are relatively separated from each other, Clamping with a skin material interposed between the resin layer and the mold,
Subsequently, the first molten resin is injected and filled into the mold cavity space between the second resin layer and the skin material, and the skin material, the first resin layer, and the second resin layer are sequentially laminated and molded.
While heating the skin material decoration layer to a set temperature set within the temperature range showing the rubbery elasticity of the skin material decoration layer using a heating means, a predetermined mold opening amount is provided between the skin material and the mold. A resin multilayer molding method characterized by being provided and held for a predetermined set time A multi-layer injection mechanism for injecting and filling the first molten resin and the second molten resin, an injection control unit for controlling the multi-layer injection mechanism, and carrying out the multi-layer molded product out of the mold while setting the skin material in the mold Input mechanism,
A temperature condition setting unit for setting and inputting a temperature for heating the skin material decoration layer within a temperature range indicating the rubbery elasticity of the skin material decoration layer, a temperature monitor unit for monitoring the temperature of the skin material decoration layer, and a temperature Heating means for heating the skin material decoration layer by comparing the signal of the monitor unit and the set value of the temperature condition setting unit;
A mold clamping condition setting unit for setting a mold clamping condition at the time of injection filling of the first molten resin and the second molten resin, a mold opening amount value and a mold opening holding time of the mold clamping operation linked with the heating means, and the mold clamping condition And a mold clamping control unit that controls a mold clamping mechanism based on a set value of the setting unit.

Images