JPH1199536A - Injection molding simultaneous patterning apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the clogging of the suction port opened to a sheet fixing suction groove even if resin burr is generated in an injection molding method to dispense with complicated disassembling cleaning in an injection molding simultaneous patterning apparatus and method. SOLUTION: A sheet fixing suction groove 16 for sucking a pattern sheet S under vacuum so as to partially or entirely surround the cavity 13 is formed to the periphery of the cavity 13 in the parting surface 14 of a female mold 12. The vacuum suction holes 17, 17... formed in the female mold 12 are opened to the sheet fixing suction groove 16 and one or a plurality of flash stopping grooves 43, 46 are formed to the predetermined region between the cavity 13 and the sheet fixing suction groove 16 independently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art There have been proposed several forms of simultaneous injection molding and painting methods in which a painting sheet is integrally adhered to the surface of an injection-molded resin molded article simultaneously with injection molding. All or some of the following steps (a) to (i) are performed in the order described, or the order of the steps is changed, and the steps are sequentially performed or a plurality of steps are simultaneously performed in parallel or in parallel. No. 50-19132, Japanese Utility Model Publication No. 3-56344, Japanese Patent Publication No. 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 female cavity 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 trimming step of separating a portion of the painted sheet to be attached to the injection molded product from another portion (unnecessary portion). (I) A take-out step of taking out the injection-molded product to which the painting sheet is adhered 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 product to form a decorative layer. On the other hand, when the painting sheet is a transfer sheet, the support sheet of the decorative sheet integrated with the surface of the injection resin molded product is peeled off, and only the transfer layer such as the decorative layer is placed on the injection resin molded product side. Painting is completed by leaving it as a decorative layer.

[0007] By the way, when performing simultaneous painting by injection molding, as described in the above (d), usually, as a preforming step, the painted sheet is passed through a vacuum suction means having a vacuum suction hole or the like formed inside the female mold. A vacuum drawing step, a stretching step is required to stretch the painted sheet along the cavity of the female mold so as to closely contact the cavity, but in order to perform this stretching step more appropriately, the parting surface of the female mold is required. A suction groove for fixing the painting sheet by vacuum suction so as to partially or entirely surround the cavity, and forming the female groove in the sheet fixing suction groove. There has been proposed an injection molding simultaneous painting apparatus in which a vacuum suction hole formed inside a mold is opened (see Japanese Patent Application Laid-Open No. 4-197607).

FIG. 4 shows such an injection molding simultaneous painting apparatus.
(Schematic plan view of female mold) and FIG. 5 (Schematic cross-sectional view showing mold clamping and injection molding state) will be briefly described. Here, in order to avoid a complicated description, only a schematic configuration will be briefly described. For the details of each part, the corresponding parts in the apparatus 10 of the embodiment of the present invention shown in FIGS. 1 to 3 which will be described later are denoted by the same reference numerals and are described in detail.

A conventional simultaneous injection molding painting apparatus 50 shown in FIGS. 4 and 5 includes a female mold 12 having a nested structure composed of an aggregate of a plurality of divided portions, and runners 36 and 2.
A male mold 25 provided with book gates 37, 37;
Stepping parting surface 14 (14) of female mold 12
a, 14b, 14c, 14d) cavity 13
Is formed around the cavity 13 so as to surround the entire periphery of the cavity 13 by suctioning and fixing the painted sheet S by vacuum suction. A predetermined number of vacuum suction holes 17, 17,... Formed inside the mold 12 are opened at predetermined pitch intervals.

Between the split molds of the female mold 12, there is formed a slit-like gap 15 opening to the cavity 13 of the female mold 12, and this gap 15 and the vacuum suction holes 17, 1 are formed.
7, ... are the vacuum suction passages 1 formed in the female die 12.
8 and a conduit 19 connected to an external vacuum pump.

The female mold 12 is provided with a rectangular frame-shaped clamper 20 for pressing and fixing the picture sheet S to the upper part 14a of the parting surface 14 of the female mold 12. The clamper 20 is driven by a drive mechanism (not shown) by four connecting rods 23 slidably fitted in through holes provided near four corners of the female mold 12.
Of the upper part 14a of the parting surface 14 in the vertical direction. The male mold 2
5 is provided with a groove-shaped recess 29 capable of accommodating the clamper 20 in the mold clamping state shown in FIG.

Further, the parting surface 1 of the female mold 12
An O-ring 22 is mounted on the upper part 14 a of the fourth member 4 so as to surround the cavity 13. This O-ring 2
2. The frame-shaped clamper 20 is provided with a sheet S
Upper part 14 of parting surface 14 of female mold 12 with
When pressed against a, it functions to hermetically shut off the cavity 12 from the outside.

In the simultaneous injection molding painting apparatus 50 having such a configuration, simultaneous injection molding painting is performed as follows. First, the parting surface 14 of the female mold 12
A sheet supply step of supplying a sheet S with a picture thereon is performed,
Subsequently, a clamping step of pressing the picture sheet S with the clamper 20 against the upper portion 14a of the parting surface 14 of the female mold 12 to fix and hold the same is performed.

Next, a heating and softening step of bringing a hot plate close to the painting sheet S fixed and held by the clamper 20 and heating and softening the heating board is performed, and the painting sheet S is removed from the vacuum suction holes 17, 17 and An elongating step is performed in which the evacuation is performed through the vacuum suction passage 18 and the conduit 19 from the sheet fixing suction groove 16 and the slit-shaped gap 15 through the vacuum suction passage 18 and the conduit 19 so that the elongation is performed so as to closely contact the cavity 13 of the female mold 12. .

In the stretching step, first, the outer peripheral portion of the central portion (the portion which is brought into close contact with the cavity 13) of the painted sheet S, which is adhered to the molded product (P), is fixed to the sheet fixing portion. The drawing sheet S is drawn into the suction groove 16, whereby a moderate tension is applied to the painting sheet S, and the painting sheet S is firmly fixed in the sheet fixing suction groove 16 portion. The central portion is further extended and drawn into the cavity 13, and is finally brought into close contact with the cavity 13.

After the stretching step is performed as described above,
A mold clamping step of moving the female mold 12 to the male mold 25 side to perform mold clamping is performed. As shown in FIG. 5, the parting surface 14 (14a to 14d) of the female mold 12 and the male mold 25 are separated. The parting surface 34 (34a to 34d) is brought into contact with the painting sheet S therebetween. Thereby, the female mold 12
A molding cavity 3 corresponding to the molded product (P) to be obtained, comprising the cavities 13 and 33, is formed between the male mold 25 and the male mold 25. Runner 36 and gates 37, 37
(For convenience of illustration, in FIG. 4, the gate 37 on the female mold,
The position of the gate is shown by a dotted line at a position facing the 37, but the gates 37 and 37 themselves are perforated in the male mold 25). After the resin in the molding cavity 3 is cured, a mold opening step of separating the female mold 12 and the male mold 25 is performed, and the injection molded product (P) to which the painting sheet S is adhered is removed from the female mold. An unloading step for taking out from the mold 12 or the male mold 25 is performed.

As described above, in the simultaneous injection-molding and painting apparatus 50 in which the sheet fixing suction grooves 16 are formed on the parting surface 14 of the female mold 12, at the beginning of the stretching step, the painting sheet S Is drawn into the sheet fixing suction groove 16 and is fixed and held. Thereafter, the central portion is stretched along the cavity 13 so as to be in close contact with the cavity 13, so that the painted sheet S is moved only to the cavity portion. Wrinkling, peeling, tearing, and the like can be less likely to occur on the painted sheet as compared with those suctioned by vacuum.

[0018]

However, in the conventional simultaneous injection-molding and painting apparatus 50 provided with the suction groove 16 for fixing the sheet as described above, the following problems may occur.

That is, depending on molding conditions such as molding pressure (injection pressure and the like) and molding temperature, the painted sheet S is partially melted or broken, and is injected into the molding cavity 3 in the injection molding process. The resin which has formed becomes a burr and leaks from the melt-ruptured portion (for example, a portion indicated by X in FIG. 5) to the surface side of the painted sheet S (the side opposite to the molded product P), and the vacuum suction holes 17, 17,. Since the suction force through the sheet fixing suction groove 16 is stronger than the suction force through the slit-shaped gap 15, the leaked resin burrs pass between the pictorial sheet S and the parting surface 14 so that the sheet fixing The vacuum suction hole 1 which is pulled toward the suction groove 16 and flows into the sheet fixing suction groove 16 and is opened in the sheet fixing suction groove 16 by the resin burr Zp.
7, 17, ... sometimes clogged. In addition, the sheet S with a picture and the male parting surfaces 34b, 34d
In some cases, the molten resin leaks from the gap between them and forms resin burrs. In this case as well, the painting sheet S was cut by the suction from the vacuum suction holes 17, and penetrated and clogged the vacuum suction holes 17.

A vacuum suction hole 17 is formed by the resin burr Zp.
If the... Are clogged, it will interfere with the vacuum suction step (stretching step) at the time of subsequent molding. Therefore, it is necessary to remove the clogged resin burr Zp. It had to be disassembled and cleaned, which was troublesome.

The problems caused by the resin burrs as described above are as follows.
In normal mass production (continuous molding), this may occur depending on molding conditions. In particular, when testing equipment or performing special operations for determining mass production conditions, etc., the injection pressure should be lower than during normal mass production. Is also likely to occur if the setting is too high. Also,
At the time of the test or the like, the resin burr may be actively generated in order to determine the limit performance or the like.

More specifically, at the time of the test or the like,
If the injection pressure is excessively increased, resin burrs flow out to the outer peripheral side from the pushed-off portion of the female parting surface 14, which should not flow in, and enter the vacuum suction hole 17 from the sheet fixing suction groove 16, and remove it. They will be clogged. The resin burrs are likely to be generated around a weld portion (in the illustrated example, a central portion in the vertical (up and down) direction) where the resin injected from the gates 37 and 37 merges particularly on the side close to the two gates 37 and 37. .

Even during the special operation such as the above test,
If the vacuum suction holes are clogged by resin burrs, not only are appropriate measurement values and operation information not obtained, but also troublesome disassembly and cleaning are required as described above, and tests and research are delayed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to allow a resin fixing burr to be opened in a sheet fixing suction groove even when a resin burr occurs in an injection molding process. It is an object of the present invention to provide an apparatus and method for simultaneous painting by injection molding, in which the vacuum suction holes are not clogged, so that troublesome disassembly and cleaning are not required.

[0025]

In order to achieve the above-mentioned object, an injection-molding simultaneous painting apparatus according to the present invention comprises a female mold and a male mold, and a cavity around a cavity in a parting surface of the female mold. A sheet fixing suction groove for fixing the painting sheet by vacuum suction so as to partially or completely surround the cavity is formed, and the sheet fixing suction groove is formed inside the female mold. Vacuum suction holes are opened, and one or a plurality of burr-fixing grooves are formed at predetermined portions between the cavity and the sheet-fixing suction grooves, independently of them. Features.

A method for simultaneous painting by injection molding according to the present invention uses the above-described apparatus, and includes a sheet supplying step of supplying a painting sheet on a parting surface of the female mold; Clamping step for fixing and holding on the parting surface, and vacuum suction of the painted sheet through vacuum suction means including the vacuum suction hole and the sheet fixing suction groove formed inside the female mold,
A stretching step of stretching so as to be in close contact with the female mold cavity, a mold clamping step of moving one of the female mold and the male mold to the other side and clamping the mold, and the female mold and the male mold. An injection molding step of performing injection molding by injecting and filling a resin in a flow state from the male mold side into a cavity formed therebetween, a mold opening step of separating the female mold and the male mold, and the painted sheet Taking out the bonded injection-molded article from the female mold or the male mold, wherein the steps are described in the order described, or the order of the steps is interchanged, sequentially, or a plurality of steps are simultaneously overlapped or parallel. To be done.

In a preferred embodiment of the method of the present invention, the painting sheet is heated and softened with a hot plate or the like before or in parallel with the stretching step. The sheet fixing suction groove of the apparatus of the present invention may be a single continuous annular groove surrounding the entire circumference of the female mold cavity, or may be an intermittent groove located only at a required portion.
In the latter case, it is preferable that the sheet fixing suction grooves are formed at the four corners of the cavity or the like where the painted sheet is easily pulled.

The shape of the suction groove for fixing the sheet in a plan view is not limited to a rectangle or a straight line, but may be uneven, arcuate, curved, or the like according to the cavity shape or other conditions. By attaching irregularities or corrugations to the sheet fixing suction groove in plan view, the overall length can be increased,
It is possible to increase the force for holding and fixing the sheet at a portion provided with the irregularities and the waveform.

The width of the sheet fixing suction groove is preferably at least four times the thickness of the painting sheet so that the painting sheet can be sufficiently drawn into the suction groove, and the depth of the suction groove is set to be less than that of the drawing groove. Pictured sheet can be fixed firmly,
In addition, it is only necessary that the depth is such that it is not pulled in such that the sheet is broken, and it is preferably 200 times or less the thickness of the painting sheet.

On the other hand, the deburring groove is provided between the female mold cavity and the sheet fixing suction groove, in other words,
It is required that the female parting surface be formed at a position located on the cavity side (inner peripheral side) of the sheet fixing suction groove on the parting surface of the female mold. It may be a continuous annular groove of books, or may be an intermittent groove located only at a required part. However, resin burrs are particularly likely to occur, for example, injection from two gates on the side close to the gate It suffices if it is formed around the weld portion where the resin in the fluidized state merges.

The burr-retaining groove may have a width and depth enough to retain the resin burr so that the resin burr does not flow into the sheet-fixing suction groove. It is preferable that the depth is about the same or less and the width is about the same or more than the sheet fixing suction groove. The cross-sectional shape of the burr-retaining groove is optional. However, in order to easily remove the captured resin burr, the round shape is preferably a round shape such as a semi-circular or U-shaped cross-section. Is preferred.

In the injection molding simultaneous painting apparatus and method of the present invention having the above-described structure, the painted sheet is partially melted or broken, and the flow injected into the molding cavity in the injection molding step. Even if the resin in the state becomes a burr and leaks between the painted sheet and the parting surface from the melt fractured portion, the resin burr enters the burr-fixing groove before reaching the sheet fixing suction groove and there. Can be fastened. For this reason, it is possible to reliably prevent the vacuum suction hole which is opened in the sheet fixing suction groove from being clogged with the resin burr, while having a simple configuration in which the burr-retaining groove is simply added to the conventional female die. As a result, it is not necessary to perform a troublesome operation such as disassembling and cleaning the female mold to remove the resin burrs.

In the present invention, the male and female molds are made of metal such as iron or ceramics, and are provided with small holes (vacuum suction holes or the like) for vacuum suction or compressed air supply as required. In this case, all of the vacuum suction holes may be opened in the sheet fixing suction groove, or a part thereof may be opened in the sheet fixing suction groove, and the rest may be opened in the female mold cavity. Is also good. In addition, the female mold is composed of an aggregate of a plurality of divided parts (so-called nested structure)
Then, a slit-shaped gap may be formed between adjacent divided portions, and the gap may be used as a vacuum suction hole to perform vacuum suction.

The painting sheet may be supplied in a required amount (one shot at a time) from the state of a long continuous belt-shaped sheet wound up in a roll shape, or a single sheet cut in advance to a predetermined size. May be supplied. Further, in order to supply a painted sheet consisting of a strip-shaped sheet (the next shot portion) or a single sheet, between a female mold and a male mold arranged opposite to each other, the unwinding machine and the winding machine are used to remove the strip-shaped sheet. A roll / roll system in which one shot is continuously supplied, or a system in which the robot is transported by a robot (manipulator) or the like equipped with a suction plate or the like for holding the sheet with a picture, may be used. The roll / roll method is recommended from the aspect of properties.

Further, a clamping means is provided for fixing and holding the picture sheet on the female parting surface. As the clamping means, a frame-shaped holding plate or the like can be used, and the driving thereof can use a molding driving force such as a mold clamping operation or the power of an ejector pin driving mechanism. This is achieved by separately providing a 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 keeping the base sheet in close contact with the 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 polyvinyl chloride, acrylic, polystyrene, ABS resin, polycarbonate, polyester, polypropylene and polyethylene can be used as the base sheet. The thickness of the substrate sheet is usually 20 to 500
It is about μm. As the decorative layer, printed pattern, colored or transparent coating, metal thin film, or hard coating, anti-fog paint,
A functional layer such as 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, and is not necessary on the support sheet. 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 preferably a thermoplastic resin film having flexibility, such as polyamide such as nylon 6 or nylon 66, polyolefin such as polyethylene or polypropylene, or polyvinyl chloride, or a laminate thereof.

As the resin for injection molding, ABS (acrylonitrile-butadiene-styrene copolymer) resin,
Thermoplastic resins such as polystyrene, vinyl chloride, acrylic, and polycarbonate that have been heated and melted to be in a liquid or fluid state, or two-part curable and catalyst-curable resins such as uncured liquids such as polyurethane and polyester For example, materials conventionally known for simultaneous painting with injection molding can be used, and are selected in accordance with the required physical properties and cost of the product.

[0040]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing a female mold in one embodiment of the simultaneous injection molding painting apparatus according to the present invention, FIG. 2 is a plan view of the female mold, and FIG. 3 is mold clamping and injection between the female mold and the male mold. FIG. 3 is a cross-sectional view (vertical center cross-sectional view) along a line AA of FIG. 2 in a molded state.

Injection molding simultaneous painting apparatus 1 of the illustrated embodiment
The molded product P to be obtained by the method 0 is a L-shaped panel having a trapezoidal shape in a plan view (FIG. 2), a cross section (FIG. 3) including a long side portion Pa and a short side portion Pb, and a vertical length of about 300 mm, width (the length of the long side portion Pa is about 50 mm, length in the depth direction (height of the short side portion Pb) is about 20 mm, and thickness is about 5 to 5 mm.
It is about 10 mm.

Injection molding simultaneous painting apparatus 10 of this embodiment
Has a female mold 12 and a male mold 25 having an uneven shape corresponding to a molded product P to be obtained. The female mold 12 has a bottom fixed to a movable plate (not shown) and has a fluid pressure cylinder. The ram moves forward and backward in a horizontal direction, in other words, in a direction approaching / separating from the male mold 25.

In the present embodiment, the female mold 12 is movable 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 mode in which the female molds are vertically opposed and one of them is moved in the vertical direction.

The female mold 12 has a nested structure composed of a plurality of split molds.
2, a cavity 13 corresponding to the molded article P is formed, and a stepped parting surface 14 is formed on the outer peripheral side of the cavity 13. The parting surface 14 includes an uppermost portion 14a located at the outermost periphery, a middle portion 14b on the inner circumference side, an upper and lower inclined portion 14c (FIGS. 1 and 2) connected to the middle portion 1b, and the inclined portion. And a lower part 14d connected to the middle part 14d of the stepped parting surface 14.
4b, an annular continuous section rectangular sheet having irregularities in plan view for vacuum suction of the painting sheet S so as to surround the cavity 13 around the cavity 13 in the upper and lower inclined portions 14c and the lower portion 14d. A fixing suction groove 16 is formed, and the sheet fixing suction groove 1 is formed.
6, a predetermined number of vacuum suction holes 17 are opened at a predetermined pitch.

In the sheet fixing suction groove 16, irregularities (meanders) are formed over the entire right side in plan view (FIG. 2), and a convex portion is formed around the center of the left side in plan view. One of the reasons why is attached is that the right side is deeper (the short side portion Pb extending in the depth direction of the molded product P is located) and the central portion in the vertical direction (both right and left).
The reason for this is that the painted sheet is easily pulled strongly, so that that portion is elongated to increase the sheet suction holding force. Another reason is to secure a space for forming the burring grooves 41 to 46 as described later.

Then, between the cavity 13 and the suction groove 16 for fixing the sheet, in other words, on the parting surface 14 (14b, 14d) of the female die 12, the cavity 13 side (inside of the suction groove 16 for fixing the sheet). On the peripheral side, burring grooves 41 to 46 are formed.

More specifically, in the plan view, relatively short burrs 41 and 42 are formed on the inner peripheral side of the convex portion on the upper right side of the suction groove 16 for fixing the sheet. A relatively long burr-retaining groove 43 is formed on the inner peripheral side of the central convex portion, and a relatively short burr-retaining groove 44, 45 is formed on the inner peripheral side of the lower convex portion of the right side portion. A relatively long burring groove 46 is formed on the inner peripheral side of the convex portion at the center of the left side portion of the fixing suction groove 16.

As described above, the five burring grooves 41 to 45 are formed intermittently on the right side of the cavity 13 and the burring grooves 46 are formed at the center part on the left side. Two gates 3 for resin injection provided at 25
7 and 37 are located near the right side of the cavity 13 (however, for convenience of illustration, the gates 37 and 37 of the female cavity 13 are indicated by broken lines at positions facing the male gates 37 and 37 in FIG. Position of the gate 37)
The welded portion where the molten resin injected from 37 joins is a central portion in the vertical direction, and a weld near the gates 37 and 37 where the molten resin injected from the two gates 37 and 37 joins. This is because resin burrs are likely to occur around the portion.

In this embodiment, the sheet fixing suction groove 16 is separated from the cavity 13 of the female mold 12 by 3 to 5 mm at a position closest to the cavity 13 (concave portion) and by 10 to 12 mm at a position farthest from the cavity 13 (convex portion). It has a width of about 3 mm and a depth of about 3 mm. The burrs 41 to 46 are formed at a distance of 2 to 3 m from the cavity 13 of the female mold 12.
m, the width is about 5mm, and the depth is about 3m
m, the shortest one is about 10 to 20 mm, and the longest one is 40 to 50 mm. The cross section was U-shaped.

On the other hand, a slit-like gap 15 serving as a vacuum suction hole is formed between the split dies on the right side in FIG. The slit-shaped gap 15 is formed by a rounded corner (R) that forms a corner of the cavity 13 (the intersection of the long side Pa and the short side Pb of the molded product P to be obtained) and the short section that follows. An opening is provided at a boundary between the plane part on the side Pb side. The reason why the slit-shaped gap 15 is opened at the boundary is as follows.
This is because the boundary part is a place where traces of the filaments left on the molded product P are the least noticeable due to the existence of the gap 15 used as a vacuum suction hole.

The vacuum suction hole 17 and the slit-shaped gap 15 are connected to an external vacuum pump through a vacuum suction passage 18 and a conduit 19 formed in the female die 12 and are provided in this embodiment. In the form, the vacuum suction hole 17, the sheet fixing suction groove 16, the slit-shaped gap 15,
A vacuum suction means is constituted by the vacuum suction passage 18, the conduit 19, an external vacuum pump, and the like.

Further, the parting surface 1 of the female mold 12
An O-ring 22 is attached to the upper part 14 a of the fourth member 4 so as to surround the entire circumference of the cavity 13. When the frame-shaped clamper 20, which will be described later, is pressed against the upper portion 14a of the parting surface 14 of the female mold 12 with the painting sheet S interposed therebetween, the O-ring 22
And hermetically shut off the outside.

On the other hand, although not shown, the male mold 25 is fixed to a fixed plate on which a nozzle of an injection molding machine is mounted, and the male mold 25 corresponds to the shape of the molded product P. A cavity 33 is formed, and parting surfaces 34 (34a to 34a) are formed on the outer peripheral side of the cavity 33.
d) is formed therein, and the cavity 13 of the female mold 12 and the male mold cavity are formed in the interior thereof by forming the molten resin from the nozzle of the injection molding machine between the female mold 12 and the male mold 25. 33 for injecting and filling into the molding cavity 3 consisting of
7, 37 are provided. The gates 37, 37
The right side of the molding cavity 3 (short side P of the molded product P)
a) It is located near and above it.

The parting surface 34 of the male mold 25 is used.
The lower part 34a located at the outermost periphery, the middle part 34b on the inner periphery side therefrom, and the upper and lower inclined parts (not shown) connected to the middle part 34b so as to be complementary to that of the female mold 12; Upper section 3 connected to the inclined section
4d, and comes into contact with the parting surfaces 14 (14a to 14d) of the female mold 12 with the picture sheet S interposed therebetween.

The female die 12 is provided with a rectangular frame-shaped clamper 20 for pressing and fixing the painting sheet S to the parting surface 14 thereof. This clamper 2
The upper part 14a of the parting surface 14 of the female mold 12 is driven by a drive mechanism (not shown) by four connecting rods 23 slidably fitted into through holes provided near four corners of the female mold 12. It can move forward and backward in the vertical direction. The male mold 25 is provided with a groove-shaped recess 29 having a depth that allows the clamper 20 to perform a separating operation for releasing the pressing and fixing state with respect to the painting sheet S in a mold-clamped state as shown in FIG. Has been established.

In addition, here, as the above-mentioned painted sheet S, a base sheet made of an acrylic resin (having a thickness of 125 μm)
And a decoration layer (acryl resin and vinyl chloride-vinyl acetate copolymer 1:
1 weight ratio mixture) and an adhesive layer (vinyl chloride / vinyl acetate copolymer system). Lamination and lamination used as a final product while the base sheet is tightly integrated with the molded product (injection resin molded product). A sheet (laminated sheet) is used. The decorative layer (pattern layer) has a wood grain pattern formed by combining three colors of a pattern plate, and the adhesive layer has a gravure solid printing plate (screen depth of 60 μm) having a screen ruling of 40 lines / cm. This is a layer having a thickness of 2 μm formed by using (gravure printing in two colors).

In the simultaneous injection molding painting apparatus 10 of the present embodiment having the above-described configuration, simultaneous injection molding painting is performed in the following process order. First, the sheet S with a picture is supplied onto the female parting surface 14 by a sheet transport mechanism (not shown) including a transport chuck (sheet supplying step), and the parting surface of the female die 12 is supplied by the clamper 20. The upper part 14 is pressed and fixed to the upper part 14a (clamping step).

Subsequently, a planar infrared radiation type heating plate (not shown) is moved onto the painting sheet S pressed and fixed by the clamper 20, and the painting sheet S is radiated by the heating plate. In a non-contact state by heating and softening (the surface temperature of the radiating surface of the hot platen at that time is 330 ° C., and the heating time is 3 seconds) (heating softening step). By vacuum suction (about 5 seconds) from the sheet fixing suction groove 16 and the slit-shaped gap 15 through the vacuum suction passage 18 and the conduit 19, it is stretched so as to be in close contact with the cavity 13 of the female mold 12. A stretching step is performed.

In this stretching step, first, the outer peripheral portion of the central portion of the painted sheet S (the portion closely adhered along the cavity 13) to be adhered to the molded product (P) is fixed to the sheet fixing portion. The drawing sheet S is drawn into the suction groove 16, whereby a moderate tension is applied to the painting sheet S, and the painting sheet S is firmly fixed in the sheet fixing suction groove 16 portion. The central portion is further extended and drawn into the cavity 13, and is finally brought into close contact with the cavity 13. As described above, in the initial stage of the stretching process, the outer peripheral portion of the painting sheet S is drawn into the suction groove 16 for fixing the sheet, and is fixed and held.
Is stretched along and adheres to it, so that the painted sheet S is wrinkled, peeled, torn, It is possible to prevent a displacement or the like from occurring.

After the stretching step is performed as described above, a mold clamping step of moving the female mold 12 toward the male mold 25 and performing mold clamping is performed. As shown in FIG. Type 1
2 parting surface 14 (14a-14d) and male mold 25
The parting surface 34 (34a to 34d) is brought into contact with the painting sheet S therebetween. Thereby, the cavities 13 and 3 are provided between the female mold 12 and the male mold 25.
3, a molding cavity 3 corresponding to the molded product (P) to be obtained is formed. Thereafter, the runner 36 and the gates 37, 3
7 through molten resin (heat resistant ABS, resin temperature 240 °
C, a mold temperature of 60 ° C.) is injected and filled with a predetermined injection pressure, and after the resin in the molding cavity 3 is cured, the female mold 12 and the male mold 25 are separated. A mold opening step, an extraction step of taking out the injection molded product (P) to which the painting sheet S is adhered from the female mold 12 or the male mold 25, and the like are performed.

In the simultaneous injection molding painting apparatus and the injection molding simultaneous painting method using the injection molding simultaneous painting apparatus according to the present embodiment having the above-described configuration, for example, the painting sheet S is partially formed by a portion indicated by X in FIG. Melts or breaks into the mold cavity 3 in the injection molding process.
7 and 37, the molten resin is turned into burrs, and the sheet S and the parting surface 14 from the molten fractured portion X
(14b, 14d), the vacuum suction holes 17,
17, ... and the suction force through the sheet fixing suction groove 16 is stronger than the suction force through the slit-shaped gap 15, so that the leaked resin burrs Zp cause the painted sheet S and the parting surfaces 14 (14b, 14d). ), The resin burrs Zp enter the burring grooves 41 to 46 before reaching the sheet fixing suction grooves 16 and are stopped there. For this reason, although it is a simple configuration in which the burr retaining grooves 41 to 46 are simply added to the conventional female mold, it is possible to reliably prevent the vacuum suction holes that are opened in the sheet fixing suction grooves from being clogged with resin burrs. As a result, it is not necessary to perform a troublesome operation such as disassembling and cleaning by removing the female mold to remove the resin burr.

Actually, a comparative test was conducted in which the injection pressure was set higher than that in normal mass production to generate resin burrs. As a result, in the simultaneous injection molding method and apparatus 10 of this embodiment, the resin burrs were reduced as described above. Even if it occurs, it does not reach the sheet fixing suction groove 16, and the burr fastening grooves 41 to 4 in front of the sheet fixing suction groove 16.
6 and are captured.
The resin burrs captured in the step could be easily removed.

On the other hand, in the conventional device 50 shown in FIGS. 4 and 5 having no burr-fixing groove, the resin burr enters the sheet fixing suction groove 16 and the vacuum suction opening there. The holes 17, 17,... Were clogged, requiring troublesome disassembly and cleaning.

In the example of the above-mentioned embodiment, the painted sheet S is preliminarily formed on the surface of the female mold cavity 13 by vacuum forming and closely contacting (preliminary forming). The case where the resin is injected is exemplified. However, the present invention can also be applied to a case where both molds are closed and injection is performed without performing such preliminary molding, and the painted sheet is molded into a male and female cavity shape by the heat and pressure of the injection resin.

[0065]

As will be understood from the above description, according to the simultaneous painting apparatus and method for injection molding according to the present invention, a simple structure is obtained in which only a groove for burr is added to a female die having a conventional structure. However, even if the resin in the flow state injected into the molding cavity becomes burrs and leaks between the painted sheet and the parting surface, the resin burrs will not be able to reach the suction groove for fixing the sheet, but the burring grooves Since it enters inside and is fastened there, it is possible to reliably prevent the vacuum suction hole opened in the suction groove for fixing the sheet with resin burrs from being clogged. As a result, the female mold is taken down to remove the resin burrs and disassembled. The effect of eliminating troublesome work such as cleaning is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a female die of one embodiment of an injection molding simultaneous painting apparatus according to the present invention.

FIG. 2 is a schematic plan view of the female mold shown in FIG.

FIG. 3 is a cross-sectional view (central cross-sectional view in the vertical direction) of the embodiment of the simultaneous injection-molding and painting apparatus according to the present invention, taken along the line AA of FIG. 2 in a mold clamping and injection molding state.

FIG. 4 is a schematic plan view showing a female mold of an example of a conventional simultaneous injection molding painting apparatus.

5 is a diagram illustrating an example of the mold clamping and injection molding apparatus of FIG.
FIG. 5 is a cross-sectional view (central cross-sectional view in the vertical direction) taken along the line BB of FIG. 4 in an injection molding state.

[Explanation of symbols]

 S Painted sheet P Molded product to be obtained 3 Mold cavity 10 Injection molding simultaneous painting device 12 Female mold 13 Female mold cavity 14 Female mold parting surface 15 Slit-shaped gap 16 Sheet fixing suction groove 17 Vacuum suction hole 20 Frame shape Clamper 25 Male 33 Male cavity 34 Male parting surface 41-46 Deburring groove Zp Resin burr

Claims (3)

[Claims] 1. A painted sheet is provided with a female mold and a male mold, and a painted sheet is fixed around a cavity in a parting surface of the female mold so as to partially or entirely surround the cavity. A suction groove for fixing the sheet is formed, and a vacuum suction hole formed inside the female mold is opened in the suction groove for fixing the sheet, and between the cavity and the suction groove for fixing the sheet. At a given site,
An injection molding simultaneous painting apparatus, wherein one or a plurality of burr-fixing grooves are formed independently of them. 2. A simultaneous injection molding and painting method using the simultaneous injection molding and painting apparatus according to claim 1, wherein a sheet supplying step of supplying a painting sheet on the female parting surface, and the painting sheet. And a vacuum step of fixing and holding the sheet on the parting surface of the female mold, and vacuum-suctioning the picture-coated sheet through vacuum suction means formed inside the female mold, the vacuum suction holes and the sheet-fixing suction grooves. By doing so, a stretching step of stretching so as to adhere along the cavity of the female mold, a mold clamping step of moving one of the female mold and the male mold to the other side to perform mold clamping, and the female mold An injection molding step of performing injection molding by injecting and filling a resin in a flow state from the male mold side into a cavity formed between the male mold and a mold opening step of separating the female mold and the male mold, Said pictured sea Taking out the bonded injection-molded article from the female mold or the male mold, wherein the steps are described in the order described, or the order of the steps is interchanged, sequentially, or a plurality of steps are simultaneously overlapped or parallel. Injection molding simultaneous painting method adapted to be performed. 3. The simultaneous painting method for injection molding according to claim 2, wherein the painting sheet is heated and softened by a hot plate or the like before or in parallel with the stretching step.