JPH0755517B2 - Molding equipment - Google Patents

Description

The present invention relates to a molding apparatus for vacuum forming, pressure forming, or vacuum pressure forming a synthetic resin sheet, film, or the like (hereinafter simply referred to as a film). The present invention relates to a molding apparatus suitable when a thin film that is easily deformed is used.

[Conventional technology]

Conventionally, as a manufacturing device for a molded product with a painting, the same as the molded product, such as vacuum molding, pressure molding, vacuum pressure molding, etc., using a mold of an injection molding machine on a painting film such as a prepainted thermoplastic synthetic resin. An injection molding simultaneous painting apparatus is known in which a shape is given and then a resin is injected into the mold to perform painting and molding at the same time [for example, Japanese Patent Application No. 57-142398.
No. (JP-A-59-31130)]. In the device disclosed in this patent application, a part of the painting film is unrolled from a roll of strip-shaped painting film on which a large number of patterns are printed at regular intervals to a female mold for vacuum forming and injection molding, and The heating plate and the frame member which were in the position are moved in the longitudinal direction with respect to the painting film to position them at a predetermined position for the pattern, and then the pattern portion is sandwiched between the heating plate and the frame member and heated in this state. The plate and the frame member are moved in the longitudinal direction of the film in the direction opposite to the previous direction (the film is pulled out from the roll at this time), the pattern portion is made to be desired on the cavity surface of the female mold, and then heated by the heating plate. The softened film is attached to the molding surface of the female mold by vacuum forming, then the sandwiching between the heating plate and the frame member is released, and the heating plate and the frame member are repainted for sandwiching the next pattern part. The film is moved in the longitudinal direction and positioned at the next pattern portion, while the male mold is engaged with the female mold with the film attached to the molding surface and the molten resin is injected to separate the resin and the painted film. It is configured to be integrally molded. Therefore, in the above-mentioned device, by repeating the reciprocating motion of the heating plate and the frame member in the longitudinal direction of the decorative film, each pattern portion of the roll-shaped decorative film can be intermittently supplied to the female cavity surface. Is.

[Problems to be solved by the invention]

However, in such a conventional apparatus, when a film that is relatively vulnerable to heat, for example, a thin film (about 40 to 100 μ) is used as a painting film to be used, there is a problem that the positioning accuracy of the pattern is deteriorated. found. That is, in the above-mentioned conventional device, the heating plate and the frame member are moved along the painting film for positioning at a predetermined position with respect to the painting film. At that time, the painting plate before being sandwiched by the heating plate and the frame member is used. It was found that the film was heated by the heating plate and expanded and contracted, impeding accurate alignment.

Therefore, as a solution to this problem, the inventors of the present invention, as shown in FIG. 12, have a female mold 1 having a cavity 1A.
On the other hand, the painting film 6 is conveyed by a film feeding device composed of an unwinding roll 7, a winding roll 8, a guide roller 9, etc., and a predetermined pattern portion is positioned at a position facing the cavity 1A. The heating plate 16 is pressed against the heating to heat it, vacuum forming or pressure forming is performed, and then the heating plate
We developed a device that injection-molds resin by retracting 16 to the standby position and combining the female mold 1 with the male mold for injection. Here, as the picture-bearing film 6 to be used, there are a case where a transfer film for transferring only a pattern to a molded product is used and a case where an overlay film which forms the surface of the molded product is used. However, it has been found that this device has a problem that wrinkles occur on the surface of the molded product.

As a result of diligent examination of the cause of wrinkles on the surface of the molded product, the present inventor found the following matters. That is, for example, when a transfer film is used as a painting film, after performing film molding and resin injection, the mold is opened, and the molded product is peeled from the painting film and taken out to perform one simultaneous painting operation. Although finished, when the painting film 6 is conveyed by the take-up roll 8 to perform the next step, as shown in FIG. 13, the conveyed painting film 6 has uneven portions formed by vacuum forming in the previous step. Due to the presence of 6A, wrinkles 6B are generated in the portion of the painted film 6 facing the cavity 1A.
Although the wrinkles 6B have a relatively large curvature as shown in FIG. 14, when the heating plate 16 is brought into contact with the painting film 6 having the wrinkles 6B to heat it,
Since it does not slide so much with respect to the heating plate 16, it becomes a small wrinkle 6C as shown in FIG. 15, which remains even after the vacuum forming of the painting film 6 and appears as a wrinkle on the surface of the injection molded product. Such wrinkles occur not only when the transfer film is used as the painting film but also when the overlay film is used. That is, in this case, since the film portion integrated with the molded product is punched out after the injection molding, the remaining film has a punching hole, and this hole causes a wrinkle upstream of the film during transport. Further, such wrinkles are particularly remarkable when the painted film 6 is thin.

The present invention has been made in view of the above problems, and prevents wrinkles from being generated when a film is brought into contact with a heating plate and heated even when a thin film is used. An object of the present invention is to provide a forming apparatus capable of preventing the formation of wrinkles in a formed film during forming, vacuum pressure forming and the like.

[Means for solving problems]

The present invention relates to a female mold having a cavity for vacuum forming, pressure forming or vacuum pressure forming, a film feeding device for conveying a film to be formed through a position facing the cavity, and a film feeding device facing the cavity. A heating plate for contacting and heating the film at a position, and at least 2 arranged in the film feed path immediately downstream of the female mold so that the film contacts and bends over the entire width.
The gist is a molding device having individual guides.

[Action]

According to the apparatus having the above structure, the film feeding device positions a predetermined portion of the film at a predetermined position with respect to the female cavity, and then the heating plate contacts and heats the film portion. Pressure forming or vacuum pressure forming is performed. Here, an uneven portion (or a punching hole when punching the forming portion) is formed on the film by the previous forming step, and this uneven portion (or the punching hole) is wrinkled on the upstream film portion when the film is fed. However, if the uneven portion (or punched hole) passes through at least two guides arranged downstream of the mold by the film transport, the flat portion of the film spreads across the two guides over the entire width. In addition, since the contact is made at an appropriate bending angle, the influence of the uneven portion (or punching hole) on the film portion upstream of the guide is eliminated, and therefore, the wrinkle of the film in the portion facing the cavity is eliminated. Therefore, when the heating plate is pressed against the film to heat it, the film does not have wrinkles and a good shape can be formed.

〔Example〕

 Embodiments of the present invention shown in the drawings will be described below.

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to an injection molding simultaneous painting device using a transfer painting film, and FIG. 2 is a view showing the device of the embodiment in the direction of arrows II-II in FIG. FIG. In the figure, 1 is a female mold for vacuum molding or pressure molding and for injection molding, which is provided with a cavity 1A and a vacuum suction port (not shown) for communicating the cavity 1A with a vacuum suction device. 2 is a male mold provided corresponding to the female mold 1, 3 is a movable plate that holds the female mold 1 and can move toward the male mold 2, 4 is a fixed plate that holds the male mold 2, 5 is a molten resin Injection holes, which form a part of the resin injection molding device.

6 is a painting film composed of a transfer film arranged so as to run between the female die 1 and the male die 2, and 7 is a painting film 6
Is a roll for feeding the film, 8 is a roll for winding the paint film 6, and 9 is a guide roller. A drive device (not shown) is connected to the take-up roll 8, and by rotating the take-up roll 8 with the drive device, the picture film is taken up from the roll 7 and fed into the cavity 1A of the female die 1. It is designed to run in the facing position. Further, the winding roll 8 is movable in the lateral direction with respect to the film traveling direction, and the film traveling position can be adjusted in the lateral direction. This picture-bearing film 6 is formed by printing a pattern to be painted on a molded product on a base film so that it can be transferred at a predetermined pitch. Further, a positioning mark 10 in the feed direction and a positioning mark 11 in the lateral direction are provided at a constant pitch. Is printed.
Reference numerals 12 and 13 denote mark detectors for detecting the positioning marks 10 and 11, respectively. The outputs of the mark detectors 12 and 13 are the drive device for the winding roll 8 and the device for moving the winding roll 8 in the lateral direction. Used to control. That is, the paint film 6 is taken up by the take-up roll 8 in the cavity 1A.
The mark detectors 12 and 13 are positioned at positions where the positioning marks 10 and 11 are detected and stopped. At this time, the pattern portion of the decorative film 6 is positioned at a predetermined position facing the cavity. Therefore, the take-up roll 8, the guide roller 9, the mark detectors 12, 13 and the like use the painting film for the female cavity 1A.
And a predetermined pattern is positioned at a position facing the cavity. It should be noted that in order to apply the conveying force to the picture-bearing film 6, not only the case where only the winding roll 8 is driven, but the guide roller 9 downstream of the female die 1 may be driven.

14A and 14B are a pair of guides arranged in the film feed path immediately downstream of the female die 1, and 15 is a bracket for holding the guides 14A and 14B. The pair of guides 14A and 14B are the third
As shown in Fig. 4 and Fig. 4, it has a straight round bar shape,
The painting film 6 is arranged so as to be in contact with the entire width and bend and pass. With this configuration, the painting film 6 is pressed against the guides 14A and 14B, respectively, and regulated to the guide shape, and the uneven portion formed by the previous molding on the portion of the painting film 6 downstream of the guides 14A and 14B.
Even if there are 6A and cutout holes, it is possible to prevent the wrinkles from occurring by keeping the painted film portion upstream of the guides 14A and 14B flat. Here, the film bending angles θ ₁ and θ ₂ in the guides 14A and 14B are the same as those of the guide film 14A and 14B when the painting film 6 is used.
It is preferably as large as possible as long as it can be pressed with a necessary pressing force to prevent the occurrence of wrinkles in the upstream film portion. If this bending angle is made too small, the painting film 6 and the guide 14A,
The pressing force with 14B increases and the friction resistance increases, which may cause excessive elongation of the film. guide
The mounting positions of 14A and 14B are determined so that the bending angle of the film passing therethrough becomes a desired value, but since this bending angle may vary depending on the film used, it can be applied to various films. As described above, the position of the guide may be easily adjustable. The guide used in this embodiment is not limited to the case of two guides as shown in FIG. 4, but may be three guides 14A, 14B, 14C as shown in FIG. You may use a guide. Further, the guides 14A, 14B, etc. are not limited to the round bar shape, and may be a flat plate shape having an edge portion serving as a guide, or a rotatable roller.

Reference numeral 16 denotes a heating plate having a size that covers the cavity 1A of the female mold 1, and can be moved by an air cylinder 17 to a standby position that is laterally removed from the running path of the painted film and a position that covers the cavity through the painted film. is there. Further heating plate 16
An air cylinder (not shown) for moving the heating plate 16 from the position shown in FIG. The heating plate 16 has a breathable portion having a large number of ventilation holes 18 on the side facing the painting film 6.
Is connected to a vacuum source and a pneumatic source via a switching valve (not shown). Therefore, by vacuum-sucking these many vent holes 18, the painting film 6 can be adsorbed and held on the heating plate 16, and by supplying compressed air, the painting film 6 is peeled off from the heating plate 16 and the cavity is removed. It can be pressed against the inner surface. In addition, the film 6 of the heating plate 16
In order to make the portion facing to be air-permeable, it is not limited to the case where a large number of air holes 18 are provided as shown in the figure, and a porous material such as sintered metal may be arranged.

Next, the molding operation by the device having the above-mentioned configuration will be described.
As shown in FIG. 2, with the heating plate 16 in the standby position away from the traveling path of the picture film 6, the picture film 6 is conveyed by the winding roll 8 and the picture film 6 is fed by the mark detector 12. At the position where the positioning mark 10 in the direction is detected, the painting film 6 stops. At this time, the mark detector 13 monitors the positioning mark 11, and the horizontal position of the film 6 is always at the take-up roll 8.
Is adjusted by the lateral movement of the. Thus, one pattern of the painting film 6 is precisely positioned at a predetermined position facing the cavity 1A of the female die 1. Further, in the previous molding step, the uneven portion 6A was formed in the portion facing the cavity 1A, and the uneven portion 6A tends to cause wrinkles in the upstream film portion during film feeding. When the portion 6A passes through the pair of guides 14A and 14B, the influence is almost eliminated, and the guides 14A and 14B
The film portion upstream of B became flat and wrinkles did not occur.

Next, the heating plate 16 is moved to a position facing the cavity 1A of the female die 1 by the air cylinder 17, and is then pressed against the female die 1 by the air cylinder (not shown) as shown in FIG. The picture film 6 is sandwiched between the heating plate 16 and the heating plate 16. At this time, a large number of vent holes 18 of the heating plate 16 are vacuum-sucked, and the decorative film 6 is adsorbed and held on the heating plate and is heated and softened by the heating plate. Heating plate 16
Simultaneously with the heating by, the inside of the cavity 1A is exhausted, and compressed air is supplied to the ventilation holes 18 of the heating plate 16 when the painting film 6 is sufficiently heated and softened. As a result, the painting film 6 is instantaneously deformed and pressed against the inner surface of the cavity as shown in FIG. 9, and is shaped into a shape that fits the inner surface of the cavity. Here, since the film portion before contacting the heating plate 16 is flat and has no wrinkles, no wrinkling occurs even when the film is adsorbed and held by the heating plate 16, and therefore, after being formed in close contact with the inner surface of the cavity. Also, no wrinkle occurs in the film portion.

It should be noted that, without exhausting the inside of the cavity 1A, compressed air may be supplied to the ventilation holes 18 of the heating plate 16 and the picture-bearing film 6 may be pressed against the inner surface of the cavity only by the compressed air to be molded. However, in that case, in order to discharge the residual air in the cavity, it is necessary to provide a large number of exhaust holes on the inner surface of the cavity, and there is a risk that many exhaust holes will remain on the surface of the molded product. From this point, it is preferable to evacuate the inside of the cavity in advance as described above. In addition, it is possible to heat the painting film 6 without vacuum-adsorbing it on the heating plate 16. However, if the method is adopted in which the heating plate 16 is vacuum-adsorbed, and the vacuum is cut off and the compressed air is applied at the same time to press the decorative film 6 against the inner surface of the cavity instantaneously, the pattern of the decorative film 6 becomes unstable. A good design can be obtained without distortion.

As shown in FIG. 9, after the pictured film 6 is attached to the inner surface of the cavity 1A and molded, the heating plate 16 returns to the original standby position (position shown in FIG. 2), and as shown in FIG. The female die 1 is moved forward by the movable platen 3 and united with the male die 2, and molten resin is injected from the injection hole 5 into the cavity 1A. Female mold 1 after the injected and molded molten resin has cooled and solidified
Is retracted and opened from the male mold 2, and the molded product inside is discharged. At this time, the molded product is peeled off from the painting film 6, but the design of the painting film is transferred to the surface, and as shown in FIG. 11, resin molding with a design such as a picture 20 or a character 21 on the surface. Item 22 is obtained.

With the above, one molding operation is completed, and thereafter, by repeating the same operation, a good molded product with no wrinkles on the surface can be manufactured continuously.

The base film constituting the decorative film 6 used in the above examples has a dimensional stability at the time of printing of which the elongation at the drying temperature at the time of printing is 0.1% or less, and has a vacuum formability at a temperature of about 100 ° C. It is preferable that the resin has good heat resistance and does not melt even if it comes into contact with a molten resin of 140 ° C. or higher injected from an injection molding machine. The thickness of the base film is not particularly limited,
Not affected by heat from the heating plate when positioning the film,
In addition, wrinkles can be prevented from occurring during transportation,
It is also possible to use thin ones that are easily affected by heat (for example, about 40 to 100 μm).

In the above embodiment, straight guides were used as the guides 14A and 14B, but instead, as shown in FIGS. 6 and 7, at least the guides on the upstream side are curved in a convex shape toward the heating plate 16. The guide 14a may be used. By using the curved guide 14a in this way, the picture film 6 on the upstream side is curved in a convex shape toward the heating plate 16,
Since it comes into contact with the film from the center of the film when it comes into contact with the film 16, it is possible to more reliably prevent the wrinkle of the painted film on the heating plate, which is preferable.

Further, although the transfer film is used as the painting film in the above-mentioned embodiment, the painting film is not limited to this, and it is an overlay film which is directly joined to the surface of the molded product when it is molded to form the surface of the product. May be. When such a film for overlay is used, after the resin is injection-molded, the portion integrated with the molded product from the painting film may be punched out with a blade provided in a male mold or a female mold.

Further, in the above-mentioned embodiment, the molded product is manufactured by injecting the molten resin into the cavity of the female mold, but the present invention is not limited to this structure, and the reactive liquid resin may be injected at a low pressure or a low temperature to mold. You may

The case where the present invention is applied to the resin-molding simultaneous painting apparatus for molding a painting film and then injecting or injecting a resin has been described above, but the present invention is not limited to this case, and a female provided with a cavity is described. It goes without saying that the present invention can also be applied to a molding apparatus that uses both the mold 1 and the heating plate 16 to perform vacuum forming, pressure forming, or vacuum pressure forming only.

〔The invention's effect〕

As described above, the molding apparatus of the present invention has at least two guides so that the film contacts the entire width and passes through the film feeding path immediately downstream of the female mold having the cavity. Since the uneven parts (or punching holes) formed in the film during the previous forming pass through the guides when the film is conveyed and positioned, the flat part of the film has two full widths. It is possible to eliminate the influence of the uneven portion (or punching hole) on the film portion upstream of the guide, and to prevent the wrinkling of the film in the portion facing the cavity. Therefore, when the heating plate is pressed against the film to heat it, the film has no wrinkle and can be molded into a good shape.

[Brief description of drawings]

1 is a schematic sectional view showing an embodiment of the present invention, FIG. 2 is a side view of the apparatus of FIG. 1 as seen in the direction of arrow II-II, and FIG. 3 is a view of arrow III-III of FIG. 4 and 5 are side sectional views showing the mounting positions of the guides 14A and 14B in an enlarged manner, FIG. 5 is a side sectional view of the same portion as FIG. 4 showing another embodiment, and FIG. FIG. 7 is a sectional view of the same portion as FIG. 3 showing an embodiment, FIG. 7 is a side sectional view of an essential part in the embodiment of FIG. 6, FIG. 8, FIG. 9 and FIG.
1 is a sectional view of an essential part for explaining the operation according to the embodiment shown in FIGS. 1 and 2, FIG. 11 is a perspective view showing a molded article with a paint manufactured by the apparatus shown in FIG. 1, and FIG. 12 is the present invention. A schematic cross-sectional view of the device previously developed by the author, Fig. 13 is its schematic side view, and Fig. 14
Fig. 15 and Fig. 15 show the painting film 6 on the heating plate in the device.
It is sectional drawing which shows the state which touches. 1 ... Female type, 1A ... Cavity, 2 ... Male type 3 ... Movable platen, 4 ... Fixed platen, 5 ... Resin injection hole 6 ... Painted film, 6A ... Uneven parts 6B, 6C ... Wrinkles, 7 ... Unwinding roll 8 ... Winding roll, 9 ... Guide roll 14A, 14B ... Guide, 15 ... Bracket 16 ... Heating plate, 17 ... Air cylinder 18 ... Vent hole

Claims (1)

[Claims] 1. A female mold provided with a cavity for vacuum forming, pressure forming or vacuum pressure forming, a film feeding device for conveying a film to be formed through a position facing the cavity, and a film feeding device facing the cavity. A heating plate for contacting and heating the film at a position to be heated, and at least two films arranged in the film feeding path immediately downstream of the female mold so that the film contacts and bends over the entire width. A molding device having a guide.