JP2001079883A - Injection molding in-mold decorating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding in-mold decorating apparatus capable of preventing the generation of wrinkles in the outer peripheral corner part of a projected isolated part in a patterning sheet stretching process to obtain a decorative laminated product of high quality having no wrinkles in its window part. SOLUTION: The projected isolated part 12a projected from the bottom part of a cavity 13 is provided in a female mold 12 in order to form the window part W of a decorative laminated product to be obtained and the suction of a decorative sheet S by a vacuum suction means is preferentially performed from the vacuum suction groove provided to the root part of the outer peripheral corner part of the projected isolated part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for obtaining a decorative laminated product by integrally bonding and laminating a painted sheet on which patterns and characters are applied in a mold simultaneously with injection molding on the surface of an injection resin molded article. And a simultaneous painting apparatus for injection molding.

[0002]

2. Description of the Related Art Several methods have been proposed for simultaneous injection molding and painting methods in which a painting sheet is integrally adhered to the surface of an injection resin molded article simultaneously with injection molding.
Most of them are arranged so that all or some of the following steps (a) to (i) are performed in the stated order or permuted, and the steps are sequentially performed or a plurality of steps are simultaneously performed in parallel or in parallel. (Japanese Patent Publication No. 50-19132, Jitsuhei 3
-56344, JP-B-7-41637, etc.).

(A) A sheet supply step of supplying a picture sheet onto a female parting surface used for injection molding. (B) a clamping step of fixing and holding the painted sheet on the female parting surface; (C) A heating softening step of heating and softening the painted sheet with a hot platen or the like. (D) a stretching step (preliminary molding step) of stretching the painted sheet along the cavity of the female mold by vacuum suction and / or air supply. (E) A mold clamping step of moving one of the female mold and the male mold (usually a female mold) to the other (usually a male mold) to clamp the mold.

(F) An injection molding step of injecting and filling a resin (molten resin) in a flowing state from the male mold into a cavity formed between the female mold and the male mold to perform injection molding. (G) A mold opening step of separating the female mold and the male mold. (H) A sheet trimming step of separating a portion of the painted sheet to be attached to the injection resin molded body from another portion (excess portion). (I) A take-out step of taking out the laminated molded product on which the painted sheet is adhesively laminated from both the male and female molds.

[0005] Simultaneously performing a plurality of steps simultaneously means that a plurality of steps are included in one step. For example, in the mold clamping step (e), the painted sheet is divided into a female type and a male type. If it is not fixed and held between them, the clamping step (b) is performed simultaneously with the mold clamping step, and the painted sheet is used in the injection molding step (f). If the stretching is performed by the heat and pressure of the injected molten resin, this means that the stretching step (d) is performed simultaneously with the injection molding step.

[0006] As the painting sheet, either a laminated sheet (laminated sheet) or a transfer sheet is used depending on the product type. In the case of a laminated sheet, painting is performed as it is by injection molding. That is, all the layers of the sheet are bonded and integrated with the surface of the injection resin molded body to form a decorative layer. On the other hand, when the painting sheet is a transfer sheet, the support sheet of the painting sheet integrated with the surface of the injection resin molded body is peeled off, and only the transfer layer such as the decoration layer remains on the injection resin molding body side. Then, the painting is completed by forming a decorative layer.

[0007]

By the way, as shown in FIG. 7, for example, as shown in FIG. 7, a decorative laminated product to be obtained by the simultaneous injection molding simultaneous painting method is provided with a painted sheet S extending from the outer periphery to the inner periphery of the central portion. There is a case where a window (opening) W or the like that needs to be turned to the right is provided. In providing the window portion W and the like, usually, as shown in FIG. 6, a convex isolated portion 12a corresponding to the window portion W and the like is protruded from the bottom of the female mold cavity 13, and In the process,
The painted sheet is vacuum-suctioned through a vacuum suction hole or the like opened in the female mold cavity 13, whereby the painted sheet S is brought into close contact with the entire cavity 13, that is, the outer peripheral surface of the convex isolated portion 12 a. Thereafter, the injection molding process and the like as described above are performed.

However, conventionally, in the case where the window W or the like is formed by projecting the convex isolated portion 12a in the female cavity 13 as described above, as shown in FIG.
The painted sheet S is vacuum-sucked into the female cavity 13.
In the stretching step along the (including the convex isolated portion 12a), a wrinkle G often occurs near the root of the outer peripheral corner (here, four locations) in the convex isolated portion 12a. As described above, when the wrinkles G are generated near the root of the outer peripheral corner in the convex isolated portion 12a, as shown in FIG. 7, the wrinkles G are generated near the four corners of the window W of the obtained decorative laminate product P. And the quality of the product is greatly reduced.

The generation of the wrinkles G as described above is considered to be caused by the drawing sheet S being brought into close contact with the portions on both sides thereof before the wrinkled portions in the stretching step. As one measure for suppressing the generation of such wrinkles G, it is conceivable to adjust the heating conditions of the painted sheet, for example, to set the heating temperature of a part where wrinkles G are likely to occur to be higher than other parts. It is extremely difficult to precisely control the heating temperature of the painted sheet, and stable improvement cannot be expected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to prevent wrinkles from being generated at the outer peripheral corners of a convex isolated portion in a drawing process of a painted sheet. Accordingly, an object of the present invention is to provide an injection molding simultaneous painting apparatus capable of obtaining a high-quality decorative laminated product having no wrinkles in a window or the like.

[0011]

In order to achieve the above-mentioned object, an injection molding simultaneous painting apparatus according to the present invention basically comprises a female mold and a male mold, and a painting sheet, which is formed of a parting surface of the female mold. Clamp means for pressing and holding the painted sheet, vacuum suction means for extending the painted sheet along the cavity of the female mold, and the male mold in a cavity formed between the female mold and the male mold. Resin injection means for injecting and filling a resin in a fluid state from the side, and the female mold has a convex isolated portion projecting from the cavity bottom for forming a window or the like of a decorative laminated product to be obtained. It is characterized in that a suction of the painting sheet by the vacuum suction means is preferentially performed from an outer peripheral corner of the convex isolated portion.

In a preferred specific embodiment of the device of the present invention,
A groove or hole for vacuum suction is provided near the root of the outer peripheral corner in the convex isolated portion. In another preferred aspect, the convex isolated portion is nested, and a gap for vacuum suction is formed between the convex isolated portion and the female mold body. In this case, in a more preferred aspect, a groove for vacuum suction wider than the gap for vacuum suction is provided in the vicinity of the root of the outer peripheral corner of the convex isolated portion and / or at the opposing portion of the female mold main body opposed thereto. Or holes are provided.

In a preferred embodiment of the simultaneous injection-molding and painting apparatus according to the present invention having the above-described configuration, a groove or a hole for vacuum suction is provided near a root of an outer peripheral corner of the convex isolated portion, The painting sheet is sucked by the vacuum suction means preferentially from the outer peripheral corner of the convex isolated portion. In other words, in the step of stretching the painted sheet, the painted sheet is first suctioned through the groove or hole for vacuum suction provided near the root of the outer peripheral corner in the protruding isolated portion where wrinkles easily occur. Being
It is made to adhere along there, and after that, it is made to adhere by suction along the peripheral portions on both sides thereof.

As described above, the suction of the painting sheet is performed preferentially from the outer peripheral corner of the convex isolated portion.
In the step of stretching the painted sheet, it is possible to prevent wrinkles from being generated at the outer peripheral corners of the convex isolated portions, and as a result, it is possible to obtain a high-quality decorative laminated product having no wrinkles in the windows and the like.

Further, since it is not necessary to worry about the occurrence of wrinkles, restrictions on the heating conditions of the sheet with a picture are reduced, and the heating conditions can be applied to other problems such as pattern elongation. In the simultaneous injection molding painting apparatus of the present invention, the male and female molds are made of metal such as iron or ceramics, and small holes (vacuum suction holes, etc.) for vacuum suction or compressed air supply as necessary. Is provided.

Further, the female mold is composed of an aggregate of a plurality of divided parts (in a so-called nested structure), and a slit-like gap is formed between adjacent divided parts, and this gap is used as a vacuum suction hole for vacuum suction. May be performed. In the device of the present invention, preferably, as described above, the convex isolated portion is nested, and a gap for vacuum suction is formed between the convex isolated portion and the female mold main body. A vacuum suction groove or hole wider than the vacuum suction gap is provided in the vicinity of the root of the outer peripheral corner and / or at the opposing portion of the female mold main body opposed thereto. This is performed preferentially from the outer peripheral corner of the shape-isolated portion.

The male mold is provided with a runner and a gate for injecting a resin in a flowing state. The number, position, shape, and the like of runners and gates can be freely set in consideration of the shape of the product to be obtained.

In the apparatus of the present invention, usually, a long strip-shaped picture sheet (sheet roll) wound up in a roll shape is sequentially unwound one shot at a time from the tip end side, and the unrolled picture sheet is rolled. Sheet supply means for conveying one shot on the leading end side onto the female parting surface is provided. The sheet supply means can be roughly classified into two types depending on the transport system. One of them is described in, for example,
As can be seen in Japanese Patent Application Publication No. 0-212314 and Japanese Utility Model Publication No. 1-110185, one shot of a long strip-shaped painting sheet wound in a roll shape is unwound from a female upstream by an unwinder. And a take-up winding system (roll / roll system) in which a winding machine winds down the female mold. The other one is, for example, as disclosed in JP-A-6-315950. An unwinding machine, a transport chuck, and a receiving fixed chuck, wherein the transport chuck is used to grip the vicinity of the leading end of a long strip-shaped painted sheet unwound from the unwinding machine, and one shot thereof is taken out of the female mold party. The sheet is supplied onto the printing surface, and the leading end of the sheet is received and fixed by a receiving and fixing chuck. In this state, the painted sheet is pressed onto the female parting surface by the clamping means and fixed and held. The decorative sheet is intended to take a cut in the width direction single sheet and form conveying chuck system upstream of the clamp means.

Further, a clamping means is provided for pressing and fixing the painting sheet to the female parting surface. As the clamping means, a frame-shaped or double-girder-shaped holding plate or the like can be used, and the driving thereof can be performed by using a molding driving force such as a mold clamping operation or by using the power of an ejector pin driving mechanism. In addition to this, it is possible to provide a separate driving means such as a fluid pressure actuator.

The painted sheet is composed of a base sheet and a decorative layer laminated thereon, and is a laminated sheet (laminated sheet) used as a final product while the base sheet is tightly integrated with a molded product, or Once the painted sheet and the molded article are integrated, any transfer sheet that peels off the substrate sheet (support sheet) while leaving only the decorative layer (transfer layer) on the molded article side can be used.

In the case of the laminated sheet, a thermoplastic resin such as polyolefin resin such as polyethylene and polypropylene, polyvinyl chloride, acrylic resin, polystyrene, ABS resin, polycarbonate resin and polyester resin is used as the base sheet. Can be. The thickness of the base sheet is usually about 20 to 500 μm. As the decorative layer, a printed pattern, colored or transparent coating, a metal thin film, or a functional layer such as a hard coating film, an antifogging paint, or a conductive layer can be used.

In the case of the transfer sheet, it is for transferring a transfer layer composed of a pattern layer or the like once formed on a releasable support sheet to another transfer target. A release layer may be provided according to the conditions, and the transfer layer includes a release layer, a decorative layer, an adhesive layer, and the like, and layers other than the decorative layer are selected as necessary. The decorative layer is selected from a pattern layer, a metal thin film layer (part or entire surface) or a functional layer such as a hard coating film, an anti-fog coating film, or a conductive layer.

The support sheet is made of nylon 6, nylon 6
A flexible thermoplastic resin film such as a polyamide resin such as No. 6 or the like, a polyolefin resin such as polyethylene or polypropylene, polyvinyl chloride or the like, or a laminate thereof is preferable.

As the resin for injection molding, ABS (acrylonitrile-butadiene-styrene copolymer) resin,
Thermoplastic resins such as polystyrene, polyvinyl chloride, acrylic resin, and polycarbonate resin that have been heated and melted to be in a liquid or fluid state, or two-pack curable and catalyst-curable resins such as urethane resins and polyester resins For example, an uncured liquid, such as uncured liquid, can be made of a material that is conventionally known for simultaneous painting with injection molding, and is selected according to the required physical properties of the product, cost, and the like.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show an embodiment of a simultaneous painting apparatus for injection molding according to the present invention. The decorative laminated product to be obtained by the simultaneous injection molding and painting apparatus 10 of the present embodiment is a window W as shown in FIG.
Is a relatively deep drawn rectangular tray-shaped panel having a U-shaped vertical cross-section and having an injection resin molded body Pr (FIG. 2).
(Including the window portion W), a painting sheet S (laminate sheet) having, for example, a wood-grained decorative layer is bonded and laminated.

In the simultaneous injection molding painting apparatus 10 of the present embodiment, the female mold 12 having an uneven shape corresponding to the laminated product is provided.
And a male mold 30. The female mold 12 has a bottom (left end side in the figure) fixed to a movable plate (not shown), and a ram of a hydraulic cylinder in a horizontal direction (X direction in FIG. 1). In other words, it moves forward and backward in a direction approaching and separating from the male mold 30.

In the present embodiment, the female mold 12 is a movable mold and moves in the horizontal direction as described above. However, the present invention is not limited to this. It is also possible to adopt a form in which the female dies are vertically opposed to each other, and one of them (in this case, usually, the female dies) is moved in the vertical direction.

The female mold 12 is provided with a cavity 13 corresponding to the decorative laminated product P to be obtained, and a cavity 1 for forming a window W of the laminated product P.
3, a protruding isolated portion 12a having a rectangular cross section protruding from the bottom. This convex isolated portion 12a is
A nested mold 12 having a T-shaped cross section incorporated in the approximate center of A
B consists of the top.

In the cavity 13, a plurality of vacuum suction holes 15 for vacuum suction are opened in the vicinity of a corner so as to extend the painting sheet S along the cavity 13, and this vacuum suction hole is provided. 15, 15, ...
Is connected to a vacuum source (not shown) including an external vacuum pump and the like via a vacuum suction passage 18 and a conduit 19.

An annular communication passage 16 communicating with the vacuum suction passage 18 is provided between the vertical side portion of the nesting mold 12B and the female main body 12A, as shown in an enlarged view in FIG. A spacer for maintaining an interval is provided between (the lower surface of) the convex isolated portion 12a (the lower surface of the cavity 13) and the female mold body portion 12A (the lower surface of the cavity 13). An annular gap 17 for vacuum suction into which (not shown) or the like is inserted is formed.

Further, near the base (lower surface side) of the outer peripheral corners (four places) of the convex isolated portion 12a,
As shown in FIGS. 4 and 5 (enlarged view as viewed in the direction indicated by the arrow V in FIG. 4), a vacuum suction groove 40 (having a large thickness) wider than the vacuum suction gap 17 and communicating with the communication passage 16. Are drilled. The groove 40 is composed of an arcuate groove portion 41 having a shape along the roundness of the outer peripheral corner of the convex isolated portion 12a, and a straight line portion 42 connecting the arcuate groove portion 41 and the communication passage 16.

In addition to the above, an annular mounting groove 23 in which an O-ring 22 is mounted is provided on the outer peripheral side of the parting surface 14 of the female mold 12. The O-ring 22 hermetically seals the cavity 12 and the outside when a rectangular frame-shaped or cross-girder-shaped clamper 20, which will be described later, is pressed against the parting surface 14 of the female die 12 with the painting sheet S interposed therebetween. Acts as a barrier to

On the other hand, the male mold 30 is fixed to a fixed plate on which a nozzle of an injection molding machine is mounted.
Is provided with a convex core portion 31 corresponding to the shape of the laminated product, and has a 2
The gates 33 of the book and the runner 32 connected to the gates 33 are provided.

Although not shown, the apparatus 10 sequentially unwinds a long strip-shaped picture sheet wound up in a roll form one shot at a time from the front end side. S for one shot on the tip side of the female mold 1
A sheet feeding mechanism for conveying the sheet onto the second parting surface 14 is provided. Although not shown, this sheet feeding mechanism may use any of the above-described unwinding and winding system and the transport chuck system.

Further, the female mold 12 is supplied with the supplied 1
A rectangular frame-shaped or double-girder-shaped clamper 20 is provided to press and hold the shot-painted sheet S on the parting surface 14. This clamper 20
Can be moved back and forth in a direction perpendicular to the parting surface 14 (X direction in the figure) by driving means (not shown) through four sliding rods (not shown) connected to the four corners. Has become.

In order to perform preforming, a hot plate 80 of, for example, a non-contact infrared heating system for heating and softening the painted sheet is provided. The hot platen 80 is moved from a standby position on one side of the female mold 12 to a sheet heating position (the position shown in FIG. 1) on the parting surface 14 of the female mold 12 by a hot plate drive mechanism (not shown). I am being squeezed.

In performing simultaneous injection molding painting by the injection molding simultaneous painting apparatus 10 having the above-described configuration, first, one shot of the painted sheet S is placed on the female parting surface 14 by the sheet supply mechanism. Then, the clamper 20 is advanced to the parting surface 14 side, and the painting sheet S is pressed and fixed to the parting surface 14 by the clamper 20, and then the hot platen 80 is
Pictured sheet S pressed and fixed by clamper 20
By moving to the upper sheet heating position,
Heat softening is performed until the surface temperature becomes, for example, 100 ° C.

Subsequently, the vacuum suction passage 18, the vacuum suction hole 15 opened in the female mold cavity 13, the nesting mold 1
A communication path 16 provided between the vertical side of 2B and the female mold body 12A, between the convex isolated portion 12a (the lower surface) and the female mold body 12A (the bottom surface of the cavity 13 thereof). Vacuum suction means formed by a vacuum suction groove 17 formed near the root (lower surface side) of the outer peripheral corners (four places) of the convex isolated portion 12a, and the like, is formed. Vacuum suction is performed to stretch the painted sheet S so as to closely adhere along the female mold cavity (a stretching step in FIG. 1).

Here, in the above-mentioned stretching step, the suction of the painted sheet is performed through the vacuum suction groove 40 (see FIG. 5) provided near the root of the outer peripheral corner of the convex isolated portion 12a. This is performed preferentially from the outer corner of the shape-isolated portion 12a. In other words, in the drawing process of the painted sheet S, the painted sheet S
Around the base of the outer corner of the convex isolated portion 12a where wrinkles are likely to occur, it is sucked through the vacuum suction groove 40 provided therein and adhered along the same,
Thereafter, suction is applied through the vacuum suction gap 17 along the peripheral portions on both sides thereof.

As described above, the drawing sheet S is sucked preferentially from the outer peripheral corner of the convex isolated portion 12a. Wrinkles can be prevented from occurring, and as a result, a high-quality decorative laminated product in which windows and the like have no wrinkles can be obtained. Further, since it is no longer necessary to worry about the occurrence of wrinkles, the restrictions on the heating conditions of the sheet with a picture are reduced, and the heating conditions can be applied to other problems such as pattern elongation.

After the stretching step, as shown in FIG. 2, the female mold 12 is advanced to the male mold 30 side, and the male mold 30 and the female mold 12 are clamped. , 30 (mold clamping step), and subsequently, a resin Pr in a flowing state is injected and filled into the molding cavity, and the obtained injection resin molded body and the above-mentioned painted sheet S are laminated and integrated. (Injection molding step). After the injection resin molded body is completely solidified, the female mold 12 is retracted to the original position, and the male and female molds 12 and 30 are opened (mold). (Opening step), the obtained laminated molded product is taken out from between the male and female molds, and thereafter, a trimming step or the like of trimming an excess portion of the painted sheet in the laminated molded product is performed.

[0042]

As will be understood from the above description, according to the present invention, it is possible to prevent wrinkles from being generated at the outer peripheral corners of the convex isolated portions in the step of stretching the painted sheet, and as a result, the windows and the like can be prevented. It is possible to provide an injection molding simultaneous painting apparatus capable of obtaining a high-quality decorative laminated product without wrinkles.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the overall configuration (stretching step) of an embodiment of a simultaneous painting apparatus for injection molding according to the present invention.

FIG. 2 is a longitudinal sectional view showing an injection molding process of the apparatus shown in FIG.

FIG. 3 is a partially enlarged cross-sectional view showing the vicinity of a convex isolated portion of the device shown in FIG.

FIG. 4 is a perspective view showing a convex isolated portion of the device shown in FIG. 1;

FIG. 5 is a partially enlarged view as viewed in the direction of arrow V in FIG. 4;

FIG. 6 is a perspective view used to explain wrinkles that occur in a painted sheet.

FIG. 7 is a perspective view showing an example of a decorative laminated product in which a window has wrinkles.

[Explanation of symbols]

 S Painting Sheet W Window 10 Simultaneous Injection Molding Painting Device 12 Female Die 12a Convexed Isolated Part 12B Nested Mold 13 Cavity 14 Parting Surface 15 Vacuum Suction Hole 16 Communication Path 17 Vacuum Suction Gap 20 Clamper 30 Male Die Vacuum Suction Groove for

Claims (4)

[Claims] 1. A female mold and a male mold, clamping means for pressing and holding a picture sheet against a parting surface of the female mold, and vacuum suction for extending the picture sheet along a cavity of the female mold. Means, and resin injection means for injecting and filling a resin in a flowing state from the male mold side into a cavity formed between the female mold and the male mold, and the female mold has a decoration to be obtained. For forming windows of laminated products, etc.
A convex isolated portion projecting from the bottom of the cavity is provided, and the suction of the painted sheet by the vacuum suction means is performed.
Injection molding simultaneous painting apparatus characterized by being preferentially performed from the outer peripheral corner of the convex isolated portion. 2. The simultaneous injection-molding and painting apparatus according to claim 1, wherein a groove or a hole for vacuum suction is provided near a root of an outer peripheral corner of the convex isolated portion. 3. The convex isolated portion is of a nested type, and a vacuum suction gap is formed between the convex isolated portion and the female mold body. Injection molding simultaneous painting apparatus according to 1. 4. A groove or hole for vacuum suction wider than the gap for vacuum suction is provided near the root of the outer peripheral corner portion of the convex isolated portion and / or at an opposing portion of the female main body portion opposed thereto. The simultaneous injection molding and painting apparatus according to claim 3, wherein the apparatus is provided.