JP4321003B2 - Method for producing multilayer molded product - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer molded article in which a skin material is partially bonded and integrated to at least a part of the outer peripheral portion of a base material surface made of a thermoplastic resin, and the skin material bonded portion has a shape including a three-dimensional shape. It relates to the manufacturing method.
[0002]
[Prior art]
Multi-layer molded products in which a skin material is bonded to a base material layer made of a thermoplastic resin are used for automobile interior parts such as door trims and instrument panels, and home appliances because of their economical efficiency, light weight, and good formability. Is widely used in a wide range of other interior and exterior parts.
[0003]
As a typical example of such a multilayer molded article, a skin material is partially bonded and integrated to at least a part of the outer peripheral portion of a base material surface made of a thermoplastic resin, such as a door trim. A multilayer molded article having a shape including a three-dimensional shape is known. Conventionally, as a method for producing such a multilayer molded article, a skin material bonding part and a skin material non-bonding part are separately provided. A method of manufacturing and joining them by a method such as heat caulking in a subsequent process is known.
[0004]
This method has the advantage that the boundary between the skin material bonding part and the skin material non-bonding part is clear and excellent in the appearance of the product, but the number of processes is increased and the bonding strength is increased due to partial bonding. There was a problem of being inferior, and it was not sufficient as an industrial production method.
[0005]
In addition, as another method for producing a multilayer molded article in which the skin material is partially bonded, the skin material is supplied between molds in an open state, and the movable material provided at a position corresponding to the outer periphery of the skin material bonding portion With the weir protruding into the mold, supply molten thermoplastic resin equivalent to the base material part of the skin material bonding part, and mold clamping until the cavity clearance reaches the final product thickness. A method of supplying the remaining molten thermoplastic resin to the remaining sealed cavity space while holding the cavity clearance is known. (JP-A-8-25407).
[0006]
This method can obtain a good molded product having no problem in the bonding strength between the skin material bonding part and the non-bonding part and the appearance of the non-bonding part at low cost. When manufacturing a multilayer molded product having a three-dimensional shape such as a vertical wall portion such as a door trim, it is difficult to position the skin material, and as shown in FIG. There is a problem that the boundary portion between the joint portion and the non-sealable portion is unclear and the product appearance is inferior.
[0007]
[Problems to be solved by the invention]
For these reasons, the present inventors have integrated and integrated the skin material partially on at least a part of the outer peripheral portion of the base material surface made of thermoplastic resin, and the skin material bonding portion has a three-dimensional shape. Multi-layer molded products with a shape that includes a clear boundary between the skin material bonding part and the skin material non-bonding part, excellent product appearance, excellent mechanical strength, and low cost As a result of studies to develop a method for easy production, the present invention has been achieved.
[0008]
[Means for Solving the Problems]
That is, the present invention uses a pair of male and female molds provided with movable weirs that can project at positions corresponding to the boundary portions between the skin material bonding part and the non-bonding part in the cavity of one of the male and female molds. A multilayer molded article in which the skin material is partially bonded and integrated with at least a part of the outer peripheral portion of the surface of the base material made of thermoplastic resin, and the skin material bonded portion has a shape including a three-dimensional shape. A method of manufacturing comprising:
1) A terminal portion in which the skin material covers at least a part of the outer peripheral portion of the surface of the base material and fits inside the base material of the skin material in a state along the shape of the cavity surface when both the male and female molds are clamped Cutting the skin material in advance into a shape that matches the shape of the boundary portion between the skin material bonding portion and the non-bonding portion on the substrate surface.
2) A step of supplying the skin material to a predetermined position between the male and female molds in the open state.
3) Clamping both male and female molds to make the skin material conform to the shape of the cavity surface
4) A step of causing the movable weir to protrude into the cavity and pressing the end portion of the movable dam inside the base material of the skin material against the mold surface.
5) A step of opening the male and female molds until the cavity clearance is larger than the final product thickness while maintaining the state in which the skin material is pressed against one of the male and female mold surfaces.
6) Melting of the amount of resin necessary to form the base material portion to which the skin material is bonded, out of the total molten thermoplastic resin amount, in the cavity between the skin material and the non-skin material side mold surface Supplying a thermoplastic resin.
7) A step of clamping the mold until the final product thickness is obtained after or while supplying the molten thermoplastic resin.
8) A step of primarily cooling the thermoplastic resin in the mold.
9) The process of accommodating a movable weir in a metal mold | die.
10) A step of supplying the remaining molten thermoplastic resin into the remaining cavity while maintaining the cavity clearance.
11) A step of secondary cooling of the thermoplastic resin in the mold.
12) A step of removing the molded body with the mold open.
The manufacturing method of the multilayer molded article which consists of is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
In addition, the following description is an example of this invention, and it cannot be overemphasized that this invention is not limited to this example.
[0010]
FIG. 2 is a plan view showing a door trim (1) which is an example of a multilayer molded article manufactured by the method of the present invention. The outer peripheral portion (13) on the surface of a base material (2) made of a thermoplastic resin. Part (all on the upper end side in the drawing) is partially bonded and integrated with the surface material (3), and the surface of the base material (2) made of thermoplastic resin is the design surface. It has become.
FIG. 3 shows an example of another door trim manufactured by the method of the present invention.
In this example, the skin material (3) is partially bonded and integrated to a part of the outer peripheral portion (13) on the surface of the base material (2) made of a thermoplastic resin.
In these examples, the outer peripheral portion (upper end side in the drawing) to which the cover material of the door trim shown in the figure is bonded is not clearly shown in the drawing, but has a three-dimensional structure for its three-dimensional design. .
[0011]
Thus, in the production method of the present invention, the skin material is partially bonded and integrated to at least a part of the outer peripheral portion of the substrate surface made of the thermoplastic resin, and the skin material bonding portion is three-dimensional. The target is a multilayer molded article having a shape including a shape, but the skin material is not limited to the outer peripheral portion of the base material, and the base material (2) is made of the thermoplastic material (3). It is bonded and integrated including at least a part of the outer peripheral part (13) of the surface, and another skin material (3 ′) is bonded and integrated at a position different from the outer peripheral part of the base material (2). For example, even if another skin material (3 ′) is in contact with the skin material (3) bonded and integrated including part of the outer peripheral portion (13) as shown in FIG. Alternatively, they may be bonded independently as shown in FIG.
[0012]
FIG. 6 is a schematic cross-sectional view of an example of a mold used in the method of the present invention, which is composed of a male and female pair of male mold (4) and female mold (5). A movable weir (8) is provided at a position corresponding to the boundary between the skin material bonding portion and the non-bonding portion of the male mold (4) corresponding to the non-design surface. It has a structure that can be projected and housed in the mold opening and closing direction by a cylinder or the like (9).
[0013]
Further, the molding surface of the male mold (4) is provided with molten resin supply ports (7A, 7B) for supplying molten thermoplastic resin, and is melted into the cavity through the molten resin supply passage (6). A thermoplastic resin is supplied.
The location of the molten resin supply port (7A, 7B) is appropriately determined depending on the product shape and size, but the mold portion corresponding to the location where the skin material is pasted and the mold portion where the skin material is not pasted It is necessary to provide at least one place for each of the two, and the number thereof may be one or more.
[0014]
Also, in this example, when the thermoplastic resin supplied to the mold part corresponding to the place where the skin material is bonded and the thermoplastic resin melt supplied to the mold part where the skin material is not bonded are the same In order to show the structure, one molten resin passage has a structure branched to each molten resin supply port (7A, 7B), but the thermoplastic resin to be supplied is a skin material bonding portion and a non-bonding portion. If different from each other, an independent molten resin passage may be provided corresponding to each molten resin supply port.
[0015]
In order to effectively carry out the method of the present invention, when the skin material is set in a mold and then clamped, a mold cavity is formed without wrinkles so that an appropriate tension is applied to the skin material. For this purpose, a clamp frame (10) for clamping the end of the skin material is provided on the outer periphery of the mold of the male mold (4).
[0016]
With such a clamp frame, the end portion is fixed when the skin material is supplied between the male and female molds, and the skin material is sandwiched between the male mold (4) and the female mold (5) when clamping the mold. Appropriate tension can be applied to the material.
The skin material clamp frame (10) is connected to an air cylinder or the like (11) and operates in the mold clamping direction in conjunction with the position of the female mold (5) when the male and female molds are clamped.
[0017]
FIG. 7 is a schematic plan view of a mold part obtained by removing the female part from the mold of FIG. 6 to show the installation state of the skin material clamp frame (10), and shows the molding surface of the male mold (4). A skin material clamp frame (10) is provided on a part of the outer periphery of the mold.
The skin material clamp frame (10) is provided so that the skin material end is fixed along the outer periphery of the mold corresponding to the skin material bonding portion.
[0018]
In addition, although the metal mold | die demonstrated above showed the example of what is called a vertical type in which both male and female metal molds open and close (vertical direction), the opening and closing direction of a metal mold | die is not limited to an up-down direction at all, and a horizontal direction There is no problem even if it is a so-called horizontal type that opens and closes in the (horizontal direction).
[0019]
Hereinafter, a specific production example of a multilayer molded product will be described using this mold.
FIG. 8 is a schematic cross-sectional view of a mold where the skin material (3) is supplied between the male and female molds in the example of manufacturing the multilayer molded article having the shape shown in FIG. 2, and FIG. 9 corresponds to FIG. The supply state of the skin material at that time is shown by a schematic plan view.
[0020]
The skin material (3) is placed so as to correspond to the portion corresponding to the skin material bonding portion of the male mold (4), and its outer peripheral end is a clamp frame (10 provided on the outer peripheral portion of the male mold (4). ) And is positioned and fixed by pins or the like (not shown).
[0021]
At this time, the skin material (3) to be supplied is in a state in which the skin material conforms to the shape of the cavity surface when the male and female molds are clamped with the outer peripheral edge of the skin material fixed with a clamp frame or the like. Covers at least a part of the outer peripheral portion of the surface of the base material, and the end portion on the inner side of the base material (end that fits inside the base material) (14) is not bonded to the skin material bonding portion on the base material surface It is important to supply the shape that matches the shape of the boundary part of the part, with the cut material being cut in advance with the expected amount of skin material being clamped. If it is, a multilayer molded article having a good appearance cannot be obtained.
At this time, depending on the type of the skin material, preheating may be performed prior to supply so that the mold cavity shape can be easily aligned during mold clamping.
[0022]
As described above, after the skin material cut in advance is supplied to a predetermined position between the male and female molds in an open state, the male and female molds are clamped. (Fig. 10)
By the mold clamping, the skin material (3) is in a state along the shape of the mold cavity surface, and the base material inner side end portion (14) of the skin material not fixed is a mold corresponding to the three-dimensional shape of the base material. While being along the shape of the molding surface, the outer peripheral edge of the skin material is drawn into the outer peripheral part of the mold, and moves to a position corresponding to the boundary between the bonded part / non-bonded part after molding.
[0023]
The mold clamping amount at this time may be usually performed up to a position where the skin material contacts the molding surface of both the male and female molds.
Note that FIG. 10 shows a state where the mold is slightly opened after the mold clamping in order to make it easy to understand the condition after the mold clamping is completed.
[0024]
By clamping the mold, the movable weir (8) is protruded into the cavity by the hydraulic cylinder (9) with the skin material conforming to the shape of the mold cavity surface. The end (14) is pressed and fixed between the female mold (5) and the molding surface (FIG. 11).
This movable weir has a structure that can freely move in the opening and closing direction of the mold and interlock with the opening and closing direction of the mold.
[0025]
Next, the male and female molds are opened while maintaining the state in which the inner end of the base material of the skin material is pressed and fixed between the movable weir (8) and the female mold (5) molding surface. (Fig. 12)
Thereby, the skin material is arranged in a state substantially along the shape of the mold cavity while forming the cavity space.
[0026]
The mold opening at this time is opened up to a cavity clearance larger than the final product thickness, but specifically, depending on the type and thickness of the skin material to be used, the type and properties of the thermoplastic resin supplied thereafter, etc. It is determined.
[0027]
Next, through the molten resin supply passage (6) from the molten resin supply port (7A) to the cavity corresponding to the place where the skin material is bonded, that is, the cavity between the skin material and the non-skin material mold surface, A molten thermoplastic resin (12) having a resin amount necessary for forming a base material portion to which the skin material of the molten thermoplastic resin amount is bonded is supplied (FIG. 13).
[0028]
Thereafter, the mold is clamped until the cavity clearance reaches the final product thickness, and the cavity is filled (FIG. 14).
At this time, since the movable weir (8) is in contact with the female mold (5) via the inner end (14) of the base material of the skin material, the movable weir becomes a partition wall, and the mold is clamped. The molten thermoplastic resin (12) that is supplied flows only in the cavity corresponding to the skin material bonding portion, and the resin is placed in the adjacent cavity corresponding to the base material portion to which the skin material is not bonded. It does not protrude.
[0029]
The supply timing and mold clamping timing of the molten thermoplastic resin (12) are appropriately determined according to the molding conditions such as the type and thickness of the skin material to be used, the type of the thermoplastic resin, the resin temperature, etc. In this timing, the resin supply may be started after the mold opening shown in FIG. 12, or the resin supply may be started before the mold opening is completed. In addition, the mold clamping may be started after the resin supply is completed, or the mold clamping may be started before the resin supply is completed.
[0030]
After completion of mold clamping, the thermoplastic resin supplied and filled in the cavity corresponding to the skin material bonding portion is cooled and solidified while maintaining the cavity clearance.
This cooling is performed by maintaining the mold clamping state for a predetermined time by using the difference from the mold temperature which is lower than the temperature of the supplied molten thermoplastic resin and is usually set to about 30 to 80 ° C. and held. Is called.
[0031]
After the thermoplastic resin is cooled and solidified, the movable weir (8) is accommodated in the male mold (4) (FIG. 15).
The timing of accommodating the movable weir (8) in the male mold (4) needs to be accommodated after the thermoplastic resin has cooled and solidified, but the entire thermoplastic resin need not be completely solidified. When the movable weir is accommodated, only the surface may be solidified so that the thermoplastic resin does not protrude into the cavity space on the side where the skin material is not bonded.
[0032]
After the movable weir (8) is stored in the mold, the molten thermoplastic resin (12) is fed from the resin supply port (7B) into the remaining closed cavity space where the skin material is not bonded while maintaining the cavity clearance. Supply (Fig. 16)
At this time, it is necessary to supply the cavity clearance while maintaining the final product thickness, but the supplied molten thermoplastic resin (12) does not protrude from the surface of the product on which the skin material is bonded. As long as the molten resin supply pressure is used, the clearance between the male and female dies may be slightly widened and widened.
The thermoplastic resin supplied into the cavity on the side where the skin material is not bonded is the same as the thermoplastic resin supplied to the portion where the skin material is normally bonded, but another different molten thermoplastic resin. It may be.
[0033]
When the supply of the thermoplastic resin is completed and the cavity is filled, the filled molten thermoplastic resin is cooled (secondary cooling) and solidified. (Fig. 17)
Thereafter, the male and female molds are opened, and the product is removed from the mold, so that the thermoplastic resin base material portion to which the skin material is bonded and the thermoplastic resin base material portion to which the skin material is not bonded are the base material portions. Multi-layer molding with excellent appearance with no misalignment of the edge of the skin material, which is firmly fused and integrated between the end faces, and the inner end of the base material of the skin material that has been partially bonded is in place. Goods can be obtained.
[0034]
As mentioned above, although the manufacturing method of the multilayer molded product in which the base material portion is not foamed has been described, it is basically said that the partially foamed multilayer molded product in which the base material portion of the portion to which the skin material is bonded is foamed is also described above. It can also be produced by a similar method.
[0035]
Hereinafter, a method for producing a partially-foamed multilayer molded product in which the base material portion of the portion to which the skin material is bonded is foamed will be described.
In this case, as the thermoplastic resin for forming the base material portion of the skin material bonding portion, the steps from FIG. 8 to FIG. 14 in the above description, except that a foaming agent-containing thermoplastic resin is used. Basically the same. Therefore, in the state in which the molten thermoplastic resin shown in FIG. 14 is filled in the cavity, the filled molten thermoplastic resin is in a state containing a foaming agent.
[0036]
The molten thermoplastic resin containing the foaming agent was supplied into the cavity corresponding to the foam base material part of the skin material bonding part, and the melted thermoplastic resin containing the foaming agent was filled into the cavity by mold clamping In the state of FIG. 14, primary cooling is performed to form a skin layer on the molten thermoplastic resin in contact with the mold cavity surface.
The primary cooling time at this time varies depending on conditions such as the mold temperature, the temperature of the molten thermoplastic resin, and characteristics, but is usually about 0.1 to 5 seconds.
If the cooling time is too long, the skin layer is enlarged, and the molten thermoplastic resin in the cavity is too solid, and foaming in the next step is not sufficiently performed.
[0037]
After the predetermined skin layer is formed, when the mold cavity is expanded in the thickness direction of the molded body, it is generated by decomposition of the foaming agent confined in the unsolidified portion of the molten thermoplastic resin filled in the cavity The foamed gas expands and increases the thickness while forming a foam layer in the thickness direction of the molded body.
When the cavity clearance reaches the product thickness after foaming, the die expansion operation is stopped, and cooling is performed while maintaining the cavity clearance. (Fig. 18)
[0038]
The cooling time at this time is appropriately determined depending on conditions such as the mold temperature, the temperature of the molten thermoplastic resin, and the characteristics, but if it is too short, it is not sufficiently solidified. There is a possibility that the molten thermoplastic resin containing no foaming agent supplied into the inside of the foam enters the foamed layer, or the positional deviation of the inner end of the base material of the skin material occurs, resulting in poor appearance.
On the other hand, if the cooling time is too long, the temperature drop on the foamed layer side becomes large, and the adhesive strength with the molten thermoplastic resin supplied thereafter may be insufficient. For this reason, it is usually about 3 to 30 seconds, preferably about 5 to 20 seconds.
[0039]
After completion of the foaming and cooling process, the movable weir (8) protruding into the mold cavity is accommodated in the male mold, and the molten thermoplastic resin is filled in the remaining cavity space corresponding to the base material portion to which the skin material is not bonded. (12) is injected, supplied, and filled into the cavity. (Fig. 19)
At this time, it is necessary to supply the cavity clearance while maintaining the final product thickness, but the supplied molten thermoplastic resin (12) does not protrude from the surface of the skin material on the side where the skin material is bonded. Unless otherwise, the clearance between the male and female molds may be slightly widened and widened by the supply pressure of the molten resin.
[0040]
The thermoplastic resin supplied to the remaining cavity space corresponding to the base material portion to which the skin material is not bonded is a thermoplastic resin containing the foaming agent previously supplied to the cavity corresponding to the base material portion to which the skin material is bonded. Although it may be the same as the resin, usually a molten thermoplastic resin containing no foaming agent is supplied.
[0041]
When the supply of the thermoplastic resin is completed and the cavity is filled, the filled molten thermoplastic resin is cooled (secondary cooling) and solidified. (Fig. 20)
Thereafter, the male and female molds are opened, and the product is taken out of the mold, whereby the foamed thermoplastic resin base material portion to which the skin material is bonded and the thermoplastic resin base material portion to which the skin material is not bonded are the base materials. The outer surface of the base material inside the base material of the skin material, which is firmly fused and integrated between the end faces of the parts, is located in a predetermined position, and the outer appearance of the outer edge of the skin material is good. A multilayer molded article in which the base material portion to which the skin material is bonded is partially foamed can be obtained.
[0042]
In the multilayer molded product obtained by such a method, the shape of the boundary portion between the base material portion bonded with the skin material and the base material portion not bonded with the skin material is a flat shape as shown in FIG. However, the appearance of the boundary portion can be made more preferable by forming a concave shape as shown in part A of FIG.
[0043]
In order to make such a concave shape, a protrusion corresponding to the shape of the concave portion is provided at a position corresponding to the boundary portion of the female molding surface, and the distal end portion of the movable weir (8) is the most advanced portion of the skin material. It is sufficient to make it so as to be fitted with the protrusions.
[0044]
As the thermoplastic resin applied to the method of the present invention, resins usually used in compression molding, injection molding, extrusion molding and the like are applied as they are. Although not particularly limited, examples of such resins include polypropylene, polyethylene, acrylonitrile-styrene-butadiene block copolymers, polyamides such as polystyrene and nylon, polyvinyl chloride, polycarbonate, acrylic resins, and styrene-butadiene block copolymers. General thermoplastic resins such as EPM, EPDM and other thermoplastic elastomers, mixtures thereof, polymer alloys using these, and the like are collectively referred to as thermoplastic resins in the present invention.
[0045]
In addition, these thermoplastic resins may contain reinforcing fibers such as glass fibers that are usually used and fillers such as various inorganic or organic fillers, if necessary. Various additives such as pigments, lubricants, antistatic agents and stabilizers may be blended.
[0046]
Moreover, in order to make the base material part to which a skin material is bonded into a foamed base material part, as a foaming agent blended in the thermoplastic resin, it is used when producing a thermoplastic resin foam. Known chemical blowing agents can be used. Specifically, inorganic foaming agents such as sodium bicarbonate, ammonium bicarbonate and ammonium carbonate, nitroso compounds such as N, N'-dinitrosopentamethylenetetramine, azodicarbonamide, azo such as azobisisobutyronitrile Compounds, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, sulfonyl hydrazides such as diphenylsulfone-3,3′-disulfonyl hydrazide, and blowing agents such as p-toluenesulfonyl semicarbazide are exemplified. If necessary, salicylic acid, urea and these It is a preferred embodiment to add a foaming aid containing.
[0047]
The type of the foaming agent is selected in consideration of the melting temperature of the thermoplastic resin to be used, the target foaming ratio, and the like. The amount added is adjusted in consideration of the strength, density and the like of the target molded product, but is generally 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin. Further, in place of the chemical foaming agent, liquid or gaseous carbon dioxide and / or nitrogen may be directly injected into the molten resin, and in some cases, these may be used in combination.
[0048]
Further, the skin material applied to the method of the present invention is not particularly limited, and examples thereof include woven fabrics and knitted fabrics such as moquettes and tricots, nonwoven fabrics such as needle punch carpets, metal foils, sheets and films of thermoplastic resins and thermoplastic elastomers. It is done.
[0049]
These skin materials may be laminated skin materials having two layers or three or more layers in which foam layers and backing layers are appropriately laminated as required. Particularly, skin materials in which foam layers are laminated are preferably applied.
When a skin material in which a foam layer is laminated is used, a polyolefin foam such as polypropylene or polyethylene, a polyvinyl chloride foam, a soft or semi-rigid polyurethane foam is used as the foam layer.
[0050]
In addition, non-woven fabrics, synthetic resin sheets, and films are used as the backing layer, and natural fibers such as cotton, wool, silk, and linen, or synthetic fibers such as polyamide, polyester, and nylon are used as the fibers constituting the non-woven fabric. These can be used alone or in combination to produce nonwoven fabrics by various methods. For example, non-woven fabrics such as a needle punch type, a thermal bond type, a spun bond type, a melt blow type, and a spun lace type are listed.
[0051]
When these laminated skin materials are used, the back surface of the skin material that comes into contact with the base material portion can be heat-sealable with the thermoplastic resin that forms the base material portion on which the skin material is laminated, or the skin material. It is necessary that the thermoplastic resin is impregnated on the back surface and can be adhered to the base resin portion.
[0052]
【The invention's effect】
According to the manufacturing method of the present invention, the skin material is partially bonded and integrated to at least a part of the outer peripheral portion of the base material surface made of the thermoplastic resin, and the skin material bonding portion includes a three-dimensional shape. A multilayer molded product consisting of shapes has a clear boundary between the skin material bonding part and the skin material non-bonding part, excellent product appearance, excellent mechanical strength, and low cost and easy industrialization. Can be manufactured.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of a multilayer molded product manufactured by a conventional method.
FIG. 2 is a plan view showing an example of a multilayer molded article produced by the method of the present invention.
FIG. 3 is a plan view showing another example of a multilayer molded article produced by the method of the present invention.
FIG. 4 is a plan view showing another example of a multilayer molded article produced by the method of the present invention.
FIG. 5 is a plan view showing another example of a multilayer molded article produced by the method of the present invention.
FIG. 6 is a schematic sectional view showing an example of a mold used in the method of the present invention.
FIG. 7 is a schematic plan view showing the arrangement of the male molding surface and the clamp frame in the mold of FIG. 6;
FIG. 8 is a schematic cross-sectional view of a mold showing a state in which a skin material cut in advance is supplied between molds in the manufacturing process of the present invention.
FIG. 9 is a schematic plan view showing a state of supplying the skin material in FIG.
FIG. 10 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 11 is a schematic cross-sectional view of a mold showing the manufacturing process of the present invention.
FIG. 12 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 13 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 14 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 15 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 16 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 17 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 18 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 19 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 20 is a schematic sectional view of a mold showing the manufacturing process of the present invention.
FIG. 21 shows an example of a cross section in the vicinity of a boundary portion between a skin material bonding portion and a non-bonding portion of a multilayer molded product manufactured by the method of the present invention.
[Explanation of symbols]
1: Multilayer molded product
2: Thermoplastic resin
3: Skin material
4: Male type
5: Female type
6: Molten resin supply passage
7: Molten resin supply port
8: Movable weir
9: Hydraulic cylinder
10: Skin material clamp frame
11: Air cylinder
12: Molten thermoplastic resin
13: Substrate outer periphery
14: End portion of inner side of skin material

Claims (4)

Thermoplastic resin using a pair of male and female molds provided with a movable weir that can protrude at a position corresponding to the boundary between the skin material bonding part and the non-bonding part in the cavity of either mold The skin material is partially bonded and integrated with at least a part of the outer peripheral portion of the substrate surface, and the skin material bonded portion is a method for producing a multilayer molded article having a shape including a three-dimensional shape. And
1) When the mold is clamped, in a state along the shape of the cavity surface, the skin material covers at least a part of the outer peripheral portion of the surface of the base material, and a terminal portion that fits inside the base material of the skin material A step of cutting the skin material in advance into a shape that matches the shape of the boundary portion between the skin material bonding portion and the non-bonding portion on the substrate surface,
2) supplying the skin material to a predetermined position between the molds in an open state;
3) clamping the male and female molds to a position where the skin material comes into contact with the cavity surface of the male and female molds, causing the skin material to conform to the shape of the cavity surface, and closely contacting ;
4) projecting the movable weir into the cavity, and pressing the end portion of the movable weir at the tip of the inner surface of the skin material against the cavity surface of one of the male and female molds;
5) opening the mold until the cavity clearance is larger than the final product thickness while maintaining the state where the skin material is pressed against the cavity surface;
6) Between the skin material and the cavity surface on the non-skin material side, out of the total molten thermoplastic resin amount, the molten heat of the resin amount necessary to form the base material portion to which the skin material is bonded. Supplying a plastic resin;
7) A step of clamping until the final product thickness is reached after or while supplying the molten thermoplastic resin;
8) a step of primarily cooling the thermoplastic resin in the cavity;
9) accommodating the movable weir in a mold;
10) supplying the remaining molten thermoplastic resin into the remaining cavity while holding the cavity clearance after the movable weir is housed in the mold ;
11 ) secondary cooling of the thermoplastic resin in the mold;
12 ) taking out the molded body with the mold open,
A method for producing a multilayer molded article comprising the steps of:   The method for producing a multilayer molded article according to claim 1, wherein a skin material having a foam layer is used as the skin material. 3. The method for producing a multilayer molded article according to claim 1 , further comprising a step of foaming the thermoplastic resin by slightly opening both the male and female molds after the primary cooling in the step 8). The method for producing a multilayer molded article according to any one of claims 1 to 3, wherein the multilayer molded article is an automobile interior part.

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