JPH07227877A - Injection molding simultaneous painting method and device - Google Patents

Abstract

(57) [Abstract] [Purpose] Appropriate injection molding simultaneous painting can be performed on a molded product with uneven surface steps and a large curvature without causing large distortion or displacement. [Structure] The decorated sheet 15 is held by the sheet clamp 50 at the peripheral edge of the cavity while being projected into the molding cavity of the female die 30, and is heated and softened by the curved surface type heating plate 60, and then is sucked from the female die suction hole 32. Suction to bring it into close contact with the inner peripheral surface of the molding cavity. Next, the female die 30 and the male die 40 are united and clamped, and a molten resin is injected and filled into the molding cavity to perform injection molding. [Effect] Since the amount of displacement when preforming a heat-softened painted sheet on the female mold cavity surface can be reduced, sheet distortion, wrinkles or tears, misalignment between the decorative layer and the irregularities of the molded product, the decorative layer Distortion and the like can be reduced, and high quality painting can be performed even on a molded product having a surface uneven step or a large curved curvature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding simultaneous painting method and apparatus for painting a surface of a molded product simultaneously with injection molding, and particularly to a surface of a molded product having a relatively large curvature or uneven surface. The present invention relates to a method and an apparatus suitable for properly painting.

[0002]

2. Description of the Related Art The surface of a molded product is painted at the same time as the injection molding of a resin molded product to manufacture a molded product 13 having a pattern 11 and a character 12 formed on the surface thereof, as shown in FIG. It is being appreciated. For this simultaneous injection molding painting, a molding apparatus 10 as shown in FIG. 20 is used (JP-A-59-31130, JP-B-4-42).
172, etc.).

This device 10 includes a female die 20 and a female die 2
And a male die 25 arranged to face 0. Female 20
Is a molding cavity 2 corresponding to the contour of the molded body to be obtained.
1 is provided inside the cavity 2
1 is provided with an intake hole 22 that is moved forward and backward in a direction toward and away from the male die 25 by an advance / retreat device 23 including a cylinder or the like. Further, the male die 25 has a core portion 26 which is inserted into the cavity 21, and a pouring hole (gate) 27 of the molten resin injection device is provided therein. And the female mold 2
A hot platen 29 is arranged between 0 and the male die 25 so as to be able to move back and forth. The front surface (female mold 20 side) of the heating plate 29 is a heating surface.

In order to perform painting simultaneously with injection molding using the apparatus 10, first, a sheet 15 for painting is placed opposite to the molding cavity of the female mold 20, and the sheet 15 for painting is heated and softened by the heating plate 29. (FIG. 20), then, the opening surface of the cavity 21 is closed by sandwiching the painted sheet 15 between the female die 20 and the heating plate 29, and vacuuming is performed through the air intake hole 22 provided in the female die 20. If necessary, compressed air is supplied through vent holes (not shown) provided in the heating plate 29.

As a result, as shown in FIG. 21, the decorative sheet 15 is stretched along the inner peripheral surface of the cavity 21 and adheres thereto. Note that this step is generally called preforming. Next, after the hot platen 29 is retracted from between the two molds, the female mold 20 is advanced to merge with the male mold 25 to perform mold clamping as shown in FIG. Pouring hole 2 of the injection device provided in the male die 25 in the cavity space formed between the male die 25 and
The molten resin is injected and filled through 7, and injection molding is performed.

As a result, the painting sheet 15 in the female die 25
Is attached integrally with the injected resin (molded body P) and the mold is opened after the completion of injection molding, the molded body having the decorative sheet 15 adhered to the outer surface is taken out from the mold. here,
When the painting sheet 15 is a laminated laminated film (laminate film), it means that painting is performed as it is, and all the painting sheet 15 layers are bonded and integrated to the outer surface of the molded body P to form a decorative layer. On the other hand, a painted sheet 15
Is a transfer film, in the subsequent step, only the base film of the decorative sheet 15 integrated on the outer surface of the molded body P is peeled off, and the transfer layer such as a pattern layer is left on the molded body P side. The decoration is completed by forming a decorative layer.

[0007]

In the conventional simultaneous injection molding painting method, the painting sheet is arranged on the opening side of the molding cavity of the female mold, and it is evacuated or pushed into the molding cavity by the core member. Since the sheet is attracted to the inner peripheral surface of the cavity all at once from a flat surface, the painted sheet must be stretched in the mold cavity. The amount of stretching of the decorative sheet in the mold becomes larger as the unevenness of the surface of the molded product and the curvature become larger, and the amount of stretching of each part of the decorative sheet is not constant but varies depending on various conditions. Then, when the picture-added sheet is greatly stretched, naturally the picture layer or the like formed on it is stretched and distorted so much that it cannot be ignored, or a misalignment occurs between the picture of the picture-added sheet and the irregular shape of the molded body. The desired painting cannot be applied to the surface of the molded product. In extreme cases, wrinkles and tears may occur.

As described above, by heating and softening the decorative sheet in advance by using the hot platen, it is possible to avoid the disadvantage associated with the stretching of the decorative sheet to some extent, but even in this case, the uneven surface step and the curvature are large. When molding a product, the stretching amount and drawing amount of the painting sheet will increase, so
It was inevitable that wrinkles and distortion would occur, and it was difficult to paint as expected.

In view of the above point, the present invention provides an injection molding simultaneous painting method and a device therefor capable of appropriately painting a molded body having uneven surface steps or a large curvature without causing large distortion or positional deviation. The purpose is to provide.

[0010]

In the injection molding simultaneous painting method of the present invention, the painting sheet is held by deforming it into a shape having a smaller or smaller unevenness than that of the surface of the female molding cavity and having the same or small curvature. A step, and a step of heating and softening the held decorative sheet by a heating plate having a heating surface having a substantially same shape as the surface shape of the retained decorative sheet,
A step of bringing the softened decorative sheet into close contact with the molding cavity surface of the female mold, a step of combining the female mold and the male mold to perform mold clamping, and a molding formed between the female mold and the male mold The above object is achieved by including a step of injecting and filling a molten resin into the cavity, performing injection molding, and adhering and integrating the injection-molded product and the decorative sheet.

Further, the injection molding simultaneous painting method of the present invention is
A step of holding the picture-added sheet on the peripheral edge of the molding cavity by projecting it into a female mold cavity in a shape having a shallower unevenness or a smaller curvature than the surface of the molding cavity by a sheet clamp, and the surface of the held picture-added sheet A step of heating and softening the held decorative sheet by a heating plate having a heat generating surface of substantially the same shape, and a step of sucking the softened decorative sheet from the female mold side and closely contacting the inner peripheral surface of the molding cavity. A step of combining the female mold and the male mold to perform mold clamping, and injecting and filling a molten resin into a molding cavity formed between the female mold and the male mold to perform injection molding to obtain an injection molded product. The above-mentioned object is achieved by including the step of adhering and integrating the decorative sheet.

The simultaneous injection-molding painting apparatus of the present invention is a female mold having a molding cavity and an intake hole opening to the molding cavity, a male mold having a resin pouring hole, and a vacuum suction means connected to the intake hole. And a peripheral pressing frame that abuts the peripheral edge of the female molding cavity and a sheet pressing frame that projects from the peripheral pressing frame. A sheet clamp capable of holding, a heating plate having a three-dimensional heating surface, a means for moving the sheet clamp relative to the female mold, and the heating plate with respect to the female mold. It includes means for relatively moving, means for relatively moving the female die with respect to the male die, and sheet feeding means for feeding the painted sheet to the female die cavity surface side. To achieve the above object by.

The seat clamp may be integrated with the female die by fixing it to a sliding rod protruding from the female die surface. The heating plate includes a main body and a plurality of surface heating elements fixed to the main body, and the shape of the heating surface can be a three-dimensional curved surface. In addition, the hot platen has a flat base having a plurality of power transmission plugs on its surface, an outlet on the lower surface, and a platen block unit having a surface heating element on at least one surface other than the lower surface, and an outlet on the lower surface. A relay block unit having a plug on the upper surface thereof, and connecting the plug and the outlet so that the shape of the heating surface formed by the surface heating element has a desired three-dimensional shape, and the relay block unit on the base, The hot platen block unit may be assembled and configured.

If heating is hindered at a portion of the sheet with a sheet that is in contact with the sheet holding frame and the portion is not softened sufficiently and distortion occurs during stretching, a heater is provided in the holding frame of the sheet clamp. The sheet can be heated more uniformly. The heating of the picture-added sheet by the heating plate may be performed by a method of directly heating the picture-added sheet mainly by heat conduction (contact heating method), or by making sure that the picture part of the picture-added sheet does not come into contact with the heating surface. A method (non-contact heating method) in which the sheet is heated mainly by infrared radiation from a curved heating plate (heating surface) may be used.

As a specific means of the contact heating method, for example, the surface shape of the heating platen is the same as that of the picture-formed sheet which is deformed and held, and the surface of the heating plate is disclosed in JP-A-59-31130. There is a method in which an air intake hole similar to the above is provided and the painted sheet is brought into close contact with the surface of the hot platen by vacuum suction and heated. As a specific means of the non-contact heating method, for example, the surface shape of the hot platen is the same as that of the deformation holding sheet, and the sheet holding with the air intake hole on the surface disclosed in JP-A-5-301250 is provided. There is a method in which a peripheral wall is provided, the sheet is fixed at a distance from the surface of the heating plate by the height of the peripheral wall, and the sheet is radiantly heated.

The decorative sheet is composed of a base sheet and a decorative layer laminated on the base sheet, and is used as a final product while the base sheet is closely adhered to the molded product to be used as a final product, or once the decorative sheet and the molded sheet are formed. It is possible to use any transfer sheet in which the base material sheet is peeled off after leaving the decorative layer only on the molded product side after the product and the product are integrated. As the base sheet, a thermoplastic resin such as polyvinyl chloride, acrylic, polystyrene, ABS resin, polycarbonate, polyester, polypropylene can be used.
The thickness of the base sheet is usually about 20 to 500 μm. As the decorative layer, a printed pattern, a colored or transparent coating, a metal thin film, or the like can be used.

The female mold and the male mold used in the injection molding simultaneous painting apparatus of the present invention may basically have the same structure as the conventional one, and the concave and convex patterns are provided on the molding surfaces of the female mold and the male mold ( Therefore, an uneven pattern is formed on the molded body).
The female and male materials can be metals such as iron or ceramics. In order to suck the painted sheet softened by heating, it is preferable to provide an intake passage having one end connected to a decompression device such as a vacuum pump and the other end opened to the surface of the molding cavity in the female mold. Alternatively, the female mold may be made of porous ceramics or porous metal, and the porous structure itself may be used as an intake passage or an intake hole.

The female molding cavity may be concave or convex. Then, the unevenness of the sheet clamp and the curved surface type heating plate is determined depending on whether the molding cavity of the female mold is concave or convex. That is, when the female molding cavity is concave, the heat generation surface shape of the sheet clamp and curved surface heating plate is convex, and when the female molding cavity is convex, the sheet clamp and curved surface heating plate is The heating surface shape of is a concave surface.

The sheet clamp is of a type that can be inserted and removed between the male and female dies, that is, the sheet clamp is inserted between the male and female dies only when the sheet is clamped in the female dies, and is placed outside the dies when clamping is not required. It may be of a retractable type, or may be of a type that is integrated with a female die and clamps the sheet in the female die to become a part of the female die and clamp the die.

The curved surface heating plate may have a constant heating surface shape, or may be formed by combining a plurality of units, and the shape of the heating surface can be changed by changing the combination of the units. It may be something like this. The picture-added sheet may be supplied in a required amount from a continuous strip film wound in a coil, or may be supplied as a sheet-shaped film which is cut into a predetermined size in advance.

The injection molding according to the present invention is carried out by injecting an uncured liquid of a curable resin which is hardened by a chemical reaction, in addition to a method of injecting a thermoplastic resin which is melted by heat, and a reactive injection molding (so-called RIM molding). The method is also included. In the case of reactive injection molding, a resin "solution" that is not hot melt is used. Therefore, in the present specification, the term "molten resin" refers to a resin containing a solution of the resin in addition to the resin in the heated and molten state.

[0022]

[Working] According to the present invention, the painted sheet has uneven steps smaller than the unevenness of the female molding cavity surface, and the degree of curvature is the same as or smaller than that of the cavity surface, and wrinkles or wrinkles are formed even when not softened. It is deformed with a sheet clamp in advance to a shape that does not cause tearing, and in that state the painting sheet is softened by heating, and then the painting sheet is completely adhered to the female cavity surface (preforming is performed in two steps). Therefore, when the sheet is preformed on the female molding cavity surface, the amount of displacement of the heat-softened painted sheet is reduced. Therefore, distortion of the sheet, occurrence of wrinkles, breakage, misalignment between the decorative layer and the unevenness of the molded product, distortion of the decorative layer, and the like are reduced, and a molded body having a large uneven surface step or a large curved curvature, for example, an automobile interior member High quality painting can be done on the surface of plastic cans and plastic cans.

It is not essential to form the painted sheet "completely" in close contact with the surface of the female mold cavity, and the sheet can be deformed and molded by the heat and pressure of the molding resin to some extent. Further, according to the present invention, since the curved surface type heating plate is used and the surface shape of the heat generating surface is made substantially the same as the shape of the decorative sheet deformed and held by the sheet clamp, each part of the decorative sheet can be heated at an equal distance. Therefore, the entire surface of the sheet can be uniformly heated to be softened.

[0024]

Embodiments of the present invention will be described in detail below with reference to the drawings. [Embodiment 1] FIG. 1 is a schematic view showing an example of an injection molding simultaneous painting apparatus according to the present invention. The apparatus of the present embodiment includes a female die 30 similar to the conventional example, and a male die 40 arranged to face the female die 30. The female die 30 is provided with a molding cavity 31 corresponding to the outer shape of the molded body to be molded, and a plurality of intake holes 32 opening to the cavity 31 are provided therein. The intake hole 32 is connected to a vacuum pump (not shown) via an intake pipe 33. The male die 40 is fixed to the stationary platen 44, and the female die 30 is connected to the pressure ram 35 via the moving plate 34 so that the female die can move with respect to the male die. Further, the male mold 40 is similar to the conventional one in that the female mold cavity 3
1 has a core part to be inserted therein, and a pouring hole of a molten resin injection device is provided therein.

Between the female die 30 and the male die 40, a sheet clamp 50 and a curved surface type heating plate 60 are arranged so as to be able to move forward and backward, and the painted sheet 15 has a female die 30 and a sheet clamp 50.
Is passed through. The seat clamp 50 is made of, for example, a stainless steel plate or the like, and has a female molding cavity 31.
And a curved pressing frame 54 fixed to the peripheral pressing frame and protruding into the molding cavity during use. Curved holding frame 54
Is an unevenness smaller than the amount of unevenness on the inner surface of the cavity 31,
Further, it has the same curvature as the inner surface of the cavity 31 or a curvature smaller than that, and holds the decorative sheet 15 in a state of being pushed into the cavity 31, as described later.

Here, when the female die 30 has a concave cavity surface as shown in FIG. 1, the concave and convex amount ΔD of the inner surface of the female die cavity 31 means the cavity surface concave portion measured from the level of the parting surface 36. It is defined by the depth of the deepest part. When the female mold has a convex cavity surface as shown in FIG. 13, it is defined by the height of the highest portion of the cavity surface convex portion measured from the level of the parting surface. The unevenness amount Δd of the painted sheet 15 is defined as the height difference from the flat portion of the sheet to the highest portion or the deepest portion of the sheet. In the present invention, ΔD>
Δd.

In FIG. 1, two curved pressing frames 54 are provided at positions corresponding to both ends of the cavity 31.
The number is not necessarily limited to two, and the cavity 31
Three or more may be provided depending on the size, depth, shape, etc. The seat clamp 50 is fixed to a rod 56 of an air cylinder 55, and is put in and taken out between the female die 30 and the male die 40 by the air cylinder 55 and is brought close to the female die 30 by a drive mechanism (not shown). It is possible to move in the direction of moving in and out.

As shown in detail in FIG. 2, the curved surface type heating plate 60 is constructed by fixing a plurality of surface heating elements 62 to the surface of the heating plate main body 61 with screws 63, and the female mold 30 side is heated. Is a face. The surface heating element 62 is supplied with electric power from a power source (not shown) through the wiring 64, and the heater embedded inside uniformly heats the entire surface. This curved surface type heating plate 60 also
It is fixed to the rod 66 of the air cylinder 65, and is inserted / removed between the female die 30 and the male die 40, as in the seat clamp 50, and the direction close to the female die 30 by a drive mechanism (not shown) and It can be moved in the direction of leaving.

Next, a method of performing painting simultaneously with injection molding using the apparatus of this embodiment will be described. As shown in FIG. 3, the painted sheet 15 is fed from the unwinding roll 71 by the feeding roll 72 and runs in front of the female die 30. The other end of the sheet is pulled and driven in the direction of the arrow by means not shown so that the picture-added sheet 15 does not loosen. A desired pattern is printed on the sheet 15 at a predetermined pitch, and if it is a back-printing laminated sheet or a transfer sheet, the printed surface is set on the side opposite to the female mold 30, In the case of a laminated sheet for printing and laminating, the printing surface is set on the side of the female mold 30. A positioning mark 17 (for example, a register mark, a cross mark, a rectangle, a stripe, etc.) is printed on the sheet 15 together with the design at a predetermined pitch or endless (striped).

First, with the sheet clamp and the curved surface type heating plate retracted from between the male and female dies 30, 40, the feed roll 7
By one, the drawing sheet 15 is unwound for one shot from the unwinding roll 71. The unwinding of one shot and the positioning of the pattern with respect to the female die 30 are performed by stopping the driving of the sheet when the mark 17 on the sheet is detected by the positioning sensor 75 such as a photoelectric tube. It is general to install one pair of vertical and horizontal positioning sensors so as to enable positioning in the length direction and the horizontal direction of the picture-added sheet.

When the design of the picture-added sheet 30 is a single-color pattern on the entire surface that does not require positioning, the positioning step can be omitted. Next, the sheet clamp 50 and the curved surface type heating plate 60 are inserted between the female die 30 and the male die 40. Then, as shown in FIG. 4, the seat clamp 5
0 is driven toward the female die 30, and its surrounding holding frame 5
2 is used to clamp the painted sheet 15 on the peripheral edge of the female molding cavity. The sheet 15 is pushed into the cavity by the curved pressing frame 54 of the sheet clamp 50, and is deformed and held in a shape protruding toward the cavity side in a state in which the degree of curvature or unevenness thereof is smaller than the degree of curvature or unevenness of the female cavity surface. At this time, the opening surface of the cavity 31 is closed by the sheet 15, and an area that separates atmospheric pressure is formed during a depressurizing process in the cavity described later. The curved pressing frame 54 of the sheet clamp 50 is designed in its shape, curvature, and the like so as not to be wrinkled or torn in the sheet that is pushed and deformed in the cavity to project and deform.

While the sheet 15 is clamped to the peripheral edge of the female molding cavity in this manner, the curved surface heating plate 60 is inserted between the male and female dies, or brought closer to the clamped sheet as indicated by the broken line. Heats and softens the entire surface of the sheet uniformly. The surface shape of the heating surface of the curved surface type heating plate 60 is the same as or substantially the same as the surface shape of the sheet which is deformed and held by the sheet clamp 50 in a state of protruding into the cavity 31. The distance ΔL between the curved surface type heating plate 60 and the deformed and held sheet 15 is set to ΔL> 0 so that each part of the sheet and the heating platen surface are heated by radiant heat while maintaining a substantially equal distance in a non-contact state. Alternatively, ΔL = 0 may be set so that the sheet is brought into close contact with the surface of the heating plate to heat mainly by heat conduction. At that time, the seat portion contacting the curved pressing frame 54 of the sheet clamp 50 is the pressing frame 54.
If it is difficult to heat compared to other portions due to the shadow of No. 2, a heater may be attached to the pressing frame 54 to supplementarily heat that portion.

In any case, the curved surface type heating plate 60 of the present invention
The pictured sheet 1 whose heating surface is fixed in a state in which its heating surface is projected into the molding cavity by the sheet clamp 50.
Since it has the same or substantially the same surface shape as the surface shape of No. 5, it becomes possible to uniformly heat and soften the entire surface of the sheet. Next, as shown in FIG. 5, the vacuum pump is operated to evacuate the inside of the molding cavity 31 of the female die 30 from the intake hole 32, and the softened painted sheet 15 held by the sheet clamp 50 is moved to the inner circumference of the molding cavity. Suction to the surface and make it adhere. At this time, if necessary, an exhaust hole may be provided on the surface of the hot platen, and compressed air may be blown out from the exhaust hole to help the sheet adhere to the female cavity surface.

According to the preforming step of the present embodiment, the sheet is preliminarily projected and deformed in the female mold cavity by the sheet clamp, and in that state, the sheet is heated and softened, and then the molding cavity surface is molded. Therefore, the amount of deformation of the softened sheet when sucked and brought into close contact with the cavity surface is reduced, and it is possible to reduce sheet distortion, wrinkles, tears, and misalignment between the pattern and the unevenness of the molded product.

When the preforming is completed in this way, the sheet clamp 50 and the curved surface type heating plate 60 are moved in a direction separating from the female die 30 and retracted from both male and female dies, and as shown in FIG. After the male and female dies are clamped by the pressure ram 35, the molten resin is injected and filled into the cavity 31 from the pouring hole 47 of the injection device provided in the male die 40 to perform injection molding.

As the injection resin, in addition to thermoplastic resins such as polyvinyl chloride, polystyrene, ABS resin, acryl and polycarbonate which are melted and fluidized,
A resin liquid which is cured by a chemical reaction, such as polyurethane having an isocyanate as a curing agent, or unsaturated polyester having an isocyanate or an organic sulfonate as a curing agent, can be used.

When the injection resin is cooled and solidified in this state, the painting sheet 15 in the female die 30 is attached integrally with the injection resin. Next, as shown in FIG. 7, the male and female dies are opened, and the picture-formed compact Q is demolded and taken out. Here, when the painting sheet 15 is a laminated laminated film (laminate film), it means that the painting is performed as it is, and all the layers of the painting sheet 15 are integrally bonded to the surface of the molded body Q to form a decorative layer. (FIG. 8a). On the other hand, when the decorative sheet 15 is a transfer film, only the base material sheet 16 of the decorative sheet 15 integrated on the surface of the molded product Q is peeled off in a subsequent step, and the transfer layer 18 such as a pattern layer 18 is peeled off.
Is left on the side of the molded body Q to form a decorative layer, thereby completing the painting (FIG. 8b).

Immediately after the mold is opened, the molded product Q is often attached to the surface of the female mold cavity surface or the surface of the male mold. In order to remove the adhered molded body from the mold and ensure the state as shown in FIG. 7, although not shown, a known ejector is used to separate the molded product from the mold. As an example of the ejector, a sliding rod capable of projecting and retracting is installed in a male mold or a female mold, and after the mold is opened, the sliding rod is projected to remove the molded product from the mold. Except for the peeling process, the sliding rod is retracted to a position where its tip surface is flush with the mold surface.

It should be noted that the curved surface type heating plate only needs to have a shape of its heat generating surface similar to the shape of the sheet deformed and held by the sheet clamp, and the heating plate body is not necessarily a semi-cylindrical shape as shown in FIG. Does not have to be. For example, the heating plate body may be a curved plate-shaped member, and the heat-generating panel may be attached to the surface thereof.

Example 2 A molded body 80 as shown in FIG.
An embodiment in which the curved side face 81 and the end faces 82 and 83 are simultaneously painted will be described. In the case of the present embodiment, the shape of the female mold cavity and the shape of the male mold must naturally match the shape of the molded body 80, but the basic configuration of the apparatus is the same as that shown in FIG. . That is, the sheet clamp and the curved surface type heating platen are placed between the female mold and the male mold so as to be freely inserted and removed.

The seat clamp is, as shown in FIG.
It has a peripheral pressing frame 86 and two curved pressing frames 87a and 87b extending from it in a substantially arc shape, but the two curved pressing frames 87a and 87b are attached so as to be closer to each other as they approach the center of the pressing frame. . In this way, by making the three-dimensional shape of the curved pressing frames 87a, 87b of the sheet clamp correspond to the ridge lines 84, 85 of the molded body 80, the unevenness is smaller than the unevenness amount ΔL of the inner surface of the molding cavity, and the curvature of the inner surface of the cavity is small. It is possible to make the decorated sheet project into the cavity of the female mold so as to be deformed and held, with a smaller or the same curvature and in a shape following the shape of the inner surface of the cavity. Curved pressing frame 8 from surrounding pressing frame 86
It is needless to say that the degree of protrusion of 7a and 87b must be such that wrinkles and tears do not occur in the sheet before being softened which is deformed thereby.

Further, as shown in FIG. 11, the curved surface type heating plate has surface heating elements 88, 89 so that the heating surface thereof has substantially the same surface shape as the picture-added sheet deformed and held by the sheet clamp. Is attached around the hot platen body. In this embodiment, the surface heating element is provided not only on the curved side surface but also on the other two surfaces. This curved surface type heating plate may be heated mainly by heat conduction by closely adhering the sheet deformed and held by the sheet clamp to the entire surface, similarly to the above-described embodiment, or the sheet and the curved surface type heating plate. It may be heated mainly by radiant heat while keeping the distance between the surfaces substantially equal.

The heated and softened sheet is sucked and closely adhered to the inner peripheral surface of the cavity by vacuum sucking the inside of the molding cavity from the suction hole provided in the female mold, as in the above embodiment. According to the preforming step of this embodiment, the sheet is deformed by the sheet clamp in advance so as to have the shape of the forming cavity and is projected into the female forming cavity. The amount of deformation is reduced, and the sheet has distortion, wrinkles, and tears.
It is possible to reduce the positional deviation between the pattern and the unevenness of the molded product. Since the steps after preforming are the same as those in the first embodiment, the detailed description thereof will be omitted.

[Embodiment 3] A picture-formed molded product having a curved shape as shown in FIG. 12 and having its inner surface decorated was produced. This decorative molded product is used as an interior member of an automobile.

The structure of the injection molding simultaneous painting apparatus of this embodiment is schematically shown in FIG. In the apparatus of this embodiment, the female mold 3
The molding cavity surface of 0a is a convex surface unlike the case of the apparatus of the above embodiment. The sheet clamp 90 is composed of a curved pressing frame 91 and an auxiliary clamp 92 having a shape similar to the curved shape of the female molding cavity surface.
It is arranged between 0a and the painted sheet 15 so that it can be taken in and out. The curved heating plate 95 includes a curved plate-shaped main body 96,
It is composed of a surface heating element 97 attached to the surface of the female mold side, and is arranged between the female mold and the male mold so that it can be taken in and out, like the sheet clamp. The surface shape of the surface heating element 97 is substantially the same as the shape of the picture-added sheet 15 deformably held by the sheet clamp. Therefore, the heating surface of the curved surface heating plate of this embodiment is concave.

Next, a method for producing a picture-formed molded product shown in FIG. 12 by performing painting simultaneously with injection molding using the apparatus shown in FIG. 13 will be described. Female die 30a by pressure ram 35
Is moved to the left in the figure, the sheet clamp 90 is inserted between the female die 30a and the decorative sheet 15. The picture-added sheet 15 is driven by the feed roll 72 from the unwinding roll 71 and travels in front of the sheet clamp 90. The picture-added sheet 15 is pulled and driven in the direction of the arrow by a means (not shown) so as not to loosen. A desired pattern is printed on the sheet 15 at a predetermined pitch, and if it is a back-printed laminated sheet or transfer sheet, the printed surface is set on the side opposite to the female die 30a, In the case of printing, the printing surface is set on the side of the female die 30a. In addition, a mark 17 is attached to the painted sheet 15 together with the design.
(For example, register marks, cross marks, etc.) are printed at a predetermined pitch.

Then, the feeding sheet 72 unwinds the picture-added sheet 15 from the unwinding roller 71 for one shot. The unwinding of one shot and the positioning of the pattern with respect to the female die 30a are performed by stopping the driving of the sheet when the positioning mark 17 of the sheet is detected by the positioning sensor 75 such as a photoelectric tube. When the positioning of the sheet is completed, the sheet is fixed to the curved pressing frame 91 of the sheet clamp by the auxiliary clamp 92. The auxiliary clamp is, for example, a rod-shaped member rotatably attached to the sheet clamp, and the sheet can be sandwiched and fixed between the clamp frame and the auxiliary clamp. In this way, the seat 15 is the curved pressing frame 91 of the seat clamp.
Is deformed and held in a shape substantially similar to the molding cavity surface. If the design of the picture-added sheet 15 is a full-color monochromatic design that does not require positioning, this positioning process can be omitted.

Next, the curved surface type heating plate 95 is inserted between the female mold and the male mold, and then brought close to the sheet held by the sheet clamp to uniformly heat and soften the entire surface of the sheet. The surface shape of the heating surface of the curved heating plate 95 is the same as or substantially the same as the surface shape of the sheet that is deformed and held by the sheet clamp 90 in a state of protruding into the cavity. The heating of the sheet by this curved surface type heating plate preforms and adheres to the female mold cavity surface without losing the shape of the softening sheet, so the heating and adhesion to the female mold are performed while the softening sheet is fixedly held on the heating plate. A sheet fixing peripheral wall may be provided at the peripheral edge of the surface of the heating plate so that the sheet and the surface of the heating plate are heated by radiant heat while maintaining a substantially equal distance between the sheet and the surface of the heating plate in a non-contact state. The sheet may be suction-adhered to the air intake holes on the surface and heated mainly by heat conduction. Since the heating surface of the curved surface type heating plate 95 has the same or substantially the same surface shape as the surface shape of the sheet deformed and held by the sheet clamp 90, the entire surface of the sheet can be uniformly heated and softened.

Alternatively, as in Embodiment 4 described later, the sheet clamp is fixed to the sliding rod attached to the female die, and the male die is clamped while the sheet clamp holds the sheet against the female die ( Only the hot platen may be retracted) Injection molding may be performed.
Next, the auxiliary clamp 92 is released to release the fixing of the sheet to the sheet clamp, and the sheet clamp 90 and the curved surface type heating plate 95 are retracted from between the female mold and the male mold. Then, after the male and female dies are clamped by the pressure ram 35 to seal the inside of the molding cavity, the vacuum pump connected to the air intake hole provided in the female mold is operated to suck the softened sheet to the inner peripheral surface of the molding cavity. Make them adhere closely. Then, injection molding is performed by injecting and filling molten resin into the molding cavity from the pouring hole 47 of the injection device provided in the male die 40a.

[Embodiment 4] Another embodiment of the seat clamp used in the simultaneous injection-molding painting apparatus of the present invention will be described with reference to FIGS. 14 and 15. The seat clamp 100 according to the present embodiment includes a sliding rod 102 attached to a female die 30b.
The seat clamp is different from the seat clamp of the above-described embodiment in that it is fixed to the female mold and is integrally provided with the female mold. As indicated by the arrow in the figure, the seat clamp 100 is driven by the sliding rod 102 from the female surface toward and away from the male surface. Female mold 30b
Around the periphery of the molding cavity surface of the
4 is provided, and an O-ring 105 is attached to the outside thereof. The suction groove 104 is connected to an external vacuum exhaust device via an intake passage running inside the female mold.

As shown in FIG. 15, the painting sheet 15 runs between the female die 30b and the sheet clamp 100. The sliding rod is housed inside the female mold when the picture-added sheet is clamped, and is driven by a drive mechanism (not shown) so as to project from the female mold when the clamp is released. When the surface of the molding cavity 31b of the female mold is concave as shown in FIG. 14, the sheet clamp 100 presses the painted sheet 15 against the peripheral edge of the molding cavity and holds the sheet in a desired shape / curvature. Part, that is, the peripheral portion of the molding cavity. The airtightness between the female mold and the sheet is maintained by the O-ring 105. The sheet deformed and held by the holding frame 101 of the sheet clamp is heated and softened by a curved platen (not shown) inserted between the female mold and the male mold. The shape of the heating surface of the curved heating plate is designed to be substantially the same as the curved shape of the deformed and held sheet. The heating of the sheet by the curved surface heating plate may be performed mainly by radiant heat while keeping the sheet and the surface of the curved surface heating plate at a substantially equal distance in a non-contact state. You may make it adhere | attach a sheet | seat and heat mainly by heat conduction.

The heat-softened sheet is then sucked and adhered to the inner peripheral surface of the molding cavity by evacuating the inside of the molding cavity from the linear suction groove 104 connected to the vacuum pump. After that, evacuate the curved hot platen,
The female mold and the male mold are clamped, and the molten resin is injected and filled into the molding cavity from the pouring hole 47 of the injection device provided in the male mold 40b to perform injection molding.

Also in this embodiment, since the heating surface of the curved surface type heating plate has the same or substantially the same surface shape as that of the sheet fixed by the sheet clamp 100, the entire surface of the sheet is uniformly heated and softened. Can be made. In addition, since the sheet is deformed in advance by the sheet clamp so as to project into the female mold cavity, the amount of deformation of the sheet when sucked and adhered to the surface of the molding cavity is reduced, and distortion, wrinkles, and tear of the sheet, It is possible to reduce the positional deviation between the pattern and the unevenness of the molded product.

Although the drawing shows the case where the surface of the molding cavity of the female mold is concave, it will be apparent that this embodiment can be applied to the case where the surface of the molding cavity of the female mold is convex. However, in that case, the pressing frame 101 of the sheet clamp should be formed so as to have an unevenness smaller than the unevenness amount ΔL on the surface of the molding cavity of the female mold, and to project from the female mold with a curvature equal to or smaller than the curvature of the cavity surface. To bend.

The line-shaped suction groove 104 provided in the female die 30b has the same function as the independent suction holes shown in FIG. 1, and instead of the line-shaped suction groove 104, a large number of suction holes are provided. Needless to say, the suction holes may be provided over the entire surface of the molding cavity.

[Embodiment 5] Referring to FIGS. 16 to 18, another embodiment of the curved surface type heating plate used in the simultaneous injection molding and painting apparatus of the present invention will be described. In each of the curved surface type heating plates of the above-mentioned embodiments, the shape of the heating surface is constant, and if the shape of the molded body or sheet clamp to be manufactured changes, the curved surface type heating plate must be manufactured accordingly. The curved surface heating plate of this embodiment eliminates such inconvenience.

FIG. 16 is a schematic view of a curved surface type heating plate of this embodiment. As shown in the figure, the curved surface heating plate 110 of this embodiment is
A plurality of heating plate block units 1 on a flat plate-shaped substrate 112
13 is assembled. Hot plate block unit 11
As for the surface heating element 3, reference numeral 3 indicates that the surface heating element is attached to only one surface thereof, that is attached to two surfaces thereof, that is attached to three surfaces thereof, and that the surface heating element is not provided. There are several types such as 114, and several types in terms of thickness and shape are also prepared. By combining them appropriately and fixing them to the base with a means such as screws, the desired shape is obtained. Get the heating surface of.

Next, details of the board and the heating plate block unit and a method of assembling the heating plate block unit to the board will be described. As shown in FIG. 17, the board 112 has screw holes 115 for mounting the heating plate block unit and a plurality of power holes for supplying power to each unit (in the case of the example, 3 × 3 is 9
Individual) plugs 116 are provided. Each flag 116
Is connected to a power source (not shown) by wiring 117 extending from the board.

The hot platen block unit 113 is shown in FIG.
As shown in (a), a surface heating element 119 is attached to the surface of a block body 118 made of ceramics, ceramics or the like.
21. Hot platen block unit 1 for board 112
As shown in FIG. 17, the screws 122 and 114 are attached.
Done by At this time, the plug 116 protruding from the base is inserted into the outlet 120 of the heating plate block units 113 and 114, and the surface heating element 119 can be energized. As shown in FIG. 18B, the unit 114 that is located between the other hot platen block units and the board and is hidden inside the hot platen is the plug 1 as shown in FIG.
16 and an outlet 120 and a screw hole 121 through which a fixing screw is inserted, but does not include a surface heating element, and is used as a unit for simple relaying.

The heating surface of the curved surface heating plate according to the present embodiment is not a perfect continuous curved surface but is generally an approximate form of a desired curved surface, and may have a step as shown in FIG. However, even with this curved surface type heating plate, it is possible to uniformly heat the decorative sheet deformed and held by the sheet clamp. In addition, by increasing the number of hot platen block units arranged on the base 112 to, for example, 10 × 10 to further subdivide the partition on the base, and further preparing various surface shapes of the units of the outermost layer, The step generated on the heating surface becomes small, and it becomes possible to approximate an arbitrary curved surface with higher accuracy.

As described above, the curved surface type heating plate of this embodiment is constructed by assembling a plurality of units, and a curved surface of an arbitrary shape can be approximated by changing the combination of the units. Therefore, if a certain number of different types of units are prepared, the shape of the heat generating surface can be changed freely by changing the assembly of those units, and a new molded body is required each time the molded body to be manufactured changes. There is no need to make a hot platen.

In the present specification, the present invention has been described mainly with respect to the case where the painted surface of the molded product is a curved surface. However, in the present invention, the entire painted surface of the molded product is a smoothly continuous curved surface. It is not limited to the case. The present invention is similarly applied to the case where the painted surface of the molded product is composed of a combination of a flat surface and a curved surface, or a combination of only flat surfaces. When the pictured surface of the molded body includes a flat surface, the sheet pressing frame of the sheet clamp may include a straight line portion,
The heat generating surface of the hot platen may be partially or wholly flat.

[0063]

According to the injection forming simultaneous painting method and apparatus of the present invention, the painting sheet can be uniformly heated and softened without unevenness. In addition, because the amount of displacement when preforming a heat-softened painted sheet on the female mold cavity surface can be reduced, distortion of the sheet, generation of wrinkles and tears, misalignment between the decorative layer and the irregularities of the molded product, Distortion and the like are reduced, and high-quality painting can be performed even on a molded product having uneven surface steps and a large curved curvature.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an injection molding simultaneous painting apparatus according to the present invention.

FIG. 2 is a detailed view of the curved surface heating plate shown in FIG.

FIG. 3 is a diagram illustrating a step of performing painting simultaneously with injection molding using the simultaneous injection molding painting device of FIG.

FIG. 4 is an explanatory view of a process of clamping a decorated sheet and heating it with a curved heating plate.

FIG. 5 is an explanatory view of a process of suction-adhering the softened sheet with a paint to the inner peripheral surface of the female molding cavity.

FIG. 6 is an explanatory diagram of an injection molding process.

FIG. 7 is an explanatory diagram of a process for taking out a molded product with a picture.

FIG. 8 is an explanatory view when the decorative sheet is a laminated laminated film and when it is a transfer film.

FIG. 9 is a view showing another example of the molded body.

FIG. 10 is a schematic view of another embodiment of the seat clamp.

FIG. 11 is a schematic view of another embodiment of the curved heating plate.

FIG. 12 is a view showing another example of a molded article with a picture.

FIG. 13 is a schematic view of another embodiment of the injection molding simultaneous painting apparatus.

FIG. 14 is a schematic view of another embodiment of the seat clamp.

FIG. 15 is a view for explaining the operation of the seat clamp shown in FIG.

FIG. 16 is a schematic view of another embodiment of the curved surface type heating plate.

FIG. 17 is a view for explaining a method of assembling the hot platen block unit to the board.

FIG. 18 is an explanatory diagram of a hot platen block unit.

FIG. 19 is a view showing an example of a molded product with a picture.

FIG. 20 is an explanatory view of a conventional injection molding simultaneous painting apparatus.

FIG. 21 is an explanatory diagram of a preforming step in a conventional simultaneous injection molding painting method.

FIG. 22 is an explanatory diagram of an injection molding process in a conventional simultaneous injection molding painting method.

[Explanation of symbols]

15 ... Painting sheet, 17 ... Positioning mark, 30 ... Female mold, 31 ... Molding cavity, 32 ... Intake hole, 34 ... Moving plate, 35 ... Pressure ram, 36 ... Parting surface, 40 ... Male mold, 44 ... Fixed Board, 50 ... Sheet clamp, 52 ... Surrounding holding frame, 54 ... Curved holding frame, 60 ... Curved heating plate,
62 ... Surface heating element, 75 ... Positioning sensor, 88, 89
... Surface heating element, 90 ... Sheet clamp, 92 ... Auxiliary clamp, 95 ... Curved heating plate, 100 ... Sheet clamp, 10
2 ... Sliding rod, 104 ... Linear suction groove, 105 ... O
Rings, 110 ... Curved plate, 113, 114 ... Plate block unit, 116 ... Plug, 119 ... Surface heating element,
120 ... Outlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Shibata 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. No. 1 in Dai Nippon Printing Co., Ltd.

Claims (6)

[Claims] 1. A step of holding a decorative sheet by deforming it into a shape having unevenness shallower than that of the surface of a female molding cavity and having the same curvature or a small curvature, and a surface shape of the held decorative sheet A step of heating and softening the pictured sheet held by a hot platen having a heating surface of the same shape; a step of bringing the softened pictured sheet into close contact with the molding cavity surface of the female mold; and the female mold and the male mold. A step of combining and mold clamping, and a step of injecting and molding a molten resin into a molding cavity formed between a female mold and a male mold to perform injection molding to integrally bond an injection molded product and a painted sheet. An injection molding simultaneous painting method comprising: 2. A peripheral edge portion of the molding cavity in which a picture sheet is projected into a molding cavity of a female mold by a sheet clamp so as to have a roughness smaller than that of the surface of the molding cavity and a curvature of the same or a small curvature. A step of holding, a step of heating and softening the held decorative sheet by a heating plate having a heating surface having substantially the same shape as the surface shape of the retained decorative sheet, and sucking the softened decorative sheet from the female mold side And then closely contacting the inner peripheral surface of the molding cavity, the step of combining the female mold and the male mold to perform mold clamping, and the molten resin in the molding cavity formed between the female mold and the male mold. A method for simultaneous painting with injection molding, comprising the steps of injecting and filling, and injection-molding, and adhering and integrating the injection-molded product and the painting sheet. 3. A female mold having a molding cavity and an intake hole opening to the molding cavity, a male mold having a resin pouring hole, a vacuum suction means connected to the intake hole, and a molding cavity of the female mold. A sheet clamp that has a peripheral pressing frame that abuts the peripheral edge and a sheet pressing frame that projects from the peripheral pressing frame, and that can hold the picture-added sheet in the peripheral edge of the molding cavity in a state of protruding into the molding cavity, A heating plate having a three-dimensional heating surface, a means for moving the sheet clamp relative to the female mold, and a means for moving the heating plate relative to the female mold. Injection molding simultaneous painting, including means for moving the female die relative to the male die, and sheet feeding means for feeding a painting sheet to the female mold cavity surface side. apparatus. 4. The injection molding simultaneous painting apparatus according to claim 3, wherein the female die includes a sliding rod protruding from a surface of the female die, and the sheet clamp is fixed to the sliding rod. . 5. An injection molding, comprising: a main body; and a plurality of surface heating elements fixed to the main body, wherein a heating surface formed by the plurality of surface heating elements has a three-dimensional curved shape. Hot plate for simultaneous painting equipment. 6. A flat board having a plurality of power transmission plugs on its surface, a socket on the lower surface, and a heating plate block unit having a surface heating element on at least one surface other than the lower surface, and a socket on the lower surface. A relay block unit having a plug on the upper surface, and the plug and the outlet are connected so that the shape of the heating surface formed by the surface heating element has a desired three-dimensional shape, and the relay block unit and the heat Hot plate for injection molding simultaneous painting device, which is characterized by mounting a board block unit.