JPH05220781A - Pattern sheet feed device in injection molding simultaneous patterning mold - Google Patents

Abstract

PURPOSE:To eliminate wrinkles crossing the running direction of a pattern sheet at a right angle and to form a pattern at an accurate position by providing a pattern sheet pressing member pressing the pattern sheet allowed to protrude toward a male mold from the mating surfaces of a female mold and the male mold at the point of time of mold clamping to at least one place on the upstream and downstream sides of a cavity. CONSTITUTION:A flat recessed surface 5 is formed to a female mold 1 and a guide bar 7 is arranged above the female mold 1 at a place slightly near to a male mold 2 from a parting surface in parallel to the parting surface. A cavity 8a is formed to the parting line surface slightly above the recessed surface 5 and a clamp bar 9a pressing a pattern sheet S to the parting surface is attaches to the mold 1 at the position opposed to the cavity 8a and a clamp bar 9b is also attached to the mold 1 at the position opposed to the cavity 8b below the recessed surface 5. When an injected resin is allowed to flow in the mold 1, said resin flows while it presses the pattern sheet S but the pattern sheet S is pushed toward the male mold by the guide bar 7 and strong tension acts on the pattern sheet S in the longitudinal direction thereof to prevent the generation of wrinkles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for simultaneous painting with injection molding for pressing a continuous painting sheet having a pattern against the inner wall of a cavity by injection pressure and performing painting simultaneously with injection molding.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 11, an in-mold injection molding simultaneous painting apparatus has a movable female die 100 and a male die 101 fixed so as to face the female die 100. A continuous drawing sheet S having a pattern formed at a predetermined pitch between the two dies 100 and 101 is a supply roll 102.
Then, it travels between the winding rolls 103.
Reference sign g is a gate outlet. A pinch roller 104 is provided in the vicinity of the supply roll 102, and a sensor 105 for positioning the picture-added sheet S at a predetermined position in the cavity of the female mold 100 below the pinch roller 104.
Is provided.

In such an in-mold injection molding simultaneous painting apparatus, a plate-like product 106 as shown in FIG. 12 is formed, and a pattern P is formed on the painting surface on the upper surface of the product 106. In order to mold such a product 106, the process shown in FIG.
As shown in FIG. 3, a female mold 1 in which a cavity 108 is formed
00 is used. When the male mold 101 is overlapped so that the painting sheet S is located on the inner wall side of the cavity 108 and is ejected in this state, the continuous painting sheet S is pressed by the injection pressure, and the product 106 as shown in FIG. 12 is formed. To be done.

By the way, at the time of the above-mentioned injection molding, as shown in FIG. 14, a wrinkle W which is orthogonal to the traveling direction of the picture-added sheet may occur at the corner of the product 106. The symbol g
Indicates the location of the gate. In particular, the cavity 108
If the sheet has a quadric surface, a large area, etc., the wrinkle is likely to occur because the drawing sheet S is remarkably stretched into a three-dimensional shape by the injection pressure.

As a means for preventing the generation of such wrinkles W, it is effective to increase the tension of the picture-added sheet. Therefore, for example, the winding roll 103 is strongly driven or a dancer roller D is provided to increase the tension. ing.

[0006]

However, only by the means for strongly driving the take-up roll 103 or the means for applying the tension by the dancer roller D, the distance between the installation position of these take-up rolls and the product molding position becomes large. In addition, since the propagation of the tension is blocked by the two molds that have been clamped or the 7 lamp bars, the increase in the tension is not sufficiently transmitted, and the positional accuracy of the picture to be painted on the product is improved. Considering this, there is a limit to the increase in tension by the above-mentioned means. Therefore, the wrinkles cannot be removed sufficiently.

Therefore, according to the present invention, it is possible to obtain a molded product (product) in which a wrinkle orthogonal to the running direction of the painting sheet does not occur at the time of injection molding of the painting sheet, and a painting pattern is formed at an accurate position. An object of the present invention is to provide a painting sheet feeding device in a mold for simultaneous injection molding and painting.

[0008]

In order to solve the above-mentioned problems, the present invention has a state in which a painting sheet is arranged between molds composed of a female mold and a male mold, which are opposed to each other, and the painting sheet is sandwiched. In the injection molding simultaneous painting mold in which the injection resin is poured from the gate and molding and painting are simultaneously performed by injection pressure, at least at the time of mold clamping, from the joint surface formed by the female mold and the male mold, the male mold side A picture sheet pressing member for pressing the picture sheet projected to was provided at at least one position on the upstream side and the downstream side of the cavity.

[0009]

According to the present invention, when the drawing sheet is sandwiched between the molds and the mold is clamped, the drawing sheet pressing member pushes the drawing sheet in the direction of the female mold, thereby removing wrinkles from the drawing sheet. To be done.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. In addition, the same reference numerals are given to the parts already described, and the duplicated description will be omitted.

First Embodiment FIGS. 1 (A) and 1 (B) are a perspective view and a sectional view of a feeding device in a mold according to the first embodiment.

As shown in FIGS. 1 (A) and 1 (B), a mold for simultaneous injection-molding painting includes a movable female mold 1 and a fixed male mold 2 arranged to face the female mold 1. Consists of. Continuous picture-added sheet S in which a pattern is formed between the molds 1 and 2
Is arranged so that it can travel in the direction of arrow Y. The painting surface of the painting sheet S is oriented in two male mold directions. Here, the painting sheet S may be the transfer painting sheet S ₁ shown in FIG.
The laminated picture-added sheet S ₂ shown in FIG. 9 may be used. That is, as shown in FIG. 8, the transfer painting sheet S ₁ is provided with a decorative layer 3c made of a pattern, partial metal vapor deposition, etc. as a transfer layer on the releasable substrate film 3a. The peeling protection layer 3b and the adhesive layer 3d that form the transfer layer are formed as needed. In addition, the laminated picture-added sheet S ₂ is provided with a decorative layer 4b composed of a picture pattern, partial metal vapor deposition or the like on the base film 4c, and the adhesive layer 4a and the surface protective layer 4d are formed as necessary. .. In the case of the laminated picture sheet S ₂ , the adhesive layer 4a, the decorative layer 4b, and the base film 4c.
-The entire surface protection layer 4d remains on the product.

A flat concave surface 5 is formed on the female die 1, and the male die 2 is slightly above the parting surface (joining surface) above the female die 1.
At the side (15 mm from the parting line surface), a cylindrical bar-shaped guide bar 7 is arranged in parallel with the parting surface as a sheet pressing member for pressing the picture-added sheet S to the male die 2 side. The tension can be maintained at 5 to 20 kg, preferably by setting the distance to 5 to 15 mm. In this way, when the guide bar 7 is arranged on the opposite side of the painting surface of the painting sheet S, there is no risk of damaging the picture printed on the painting sheet S.

A recess 8a is formed on the parting line surface slightly above the recess surface 5, and a clamp bar 9a for pressing the picture-added sheet S against the parting line surface is attached at a position facing the recess 8a. .. This recess 8a
Plays a role of preventing the pressed decorative sheet S from being completely pressed against the parting line surface and not running. Similarly, a recess 8b is formed on the parting line surface below the recess surface 5, and a clamp bar 9b that presses the picture-added sheet S against the parting line surface is attached at a position facing the recess 8b.

A core portion 2a to be inserted into the recessed surface 5 is formed on the front surface of the male mold 2, and a gate 6 is formed at substantially the center of the core portion 2a. The core portion 2a and the female mold 1
A cavity is formed with the concave surface 5 of the.

Next, the molding operation of the mold configured as described above will be described. The decorative sheet S is inserted into the gap where the female die 1 and the male die 2 are arranged so as to face each other. A reference mark (not shown) is written on the picture-added sheet S, a sensor (not shown) detects the reference mark, and a picture-added sheet position adjusting device (not shown) operates to select the optimum position for molding / painting. ..
When it is not necessary to align the shape of the molded product with the pattern of the decorative layer, these reference mark, sensor, and position adjusting device are unnecessary.

Next, the female die 1 is pressed against the male die 2 to form a cavity. When the female die 1 is pressed, the picture-added sheet S is extruded to the male die 2 side by the guide bar 7 at the upper part of the die (see FIG. 1 (B)).

In this state, when the injection resin is poured from the gate 6 provided in the male mold 2, the injection resin sequentially flows toward the facing end surface while pressing the decorative sheet S. In this case, since the drawing sheet S is extruded toward the male mold 2 side by the guide bar 7, a strong tension acts in the longitudinal direction of the drawing sheet S, so that wrinkles are eliminated, and therefore, the drawing surface of the molded product is removed. Wrinkles disappear.

Second Embodiment As shown in FIG. 2, a guide bar 7 on the upstream side of the cavity is provided.
a, the guide bar 7b on the downstream side of the cavity is arranged at a position of 15 mm in the direction of the male die 2 from the parting line surface.

Third Embodiment As shown in FIG. 3, before the mold clamping, the guide bars 7c and 7d are formed.
Is arranged so as to be retracted from the parting line surface in the direction of the female mold 1, and the guide bars 7c and 7d are moved by 15 mm in the two directions of the male mold (to the right) at the time of mold clamping to increase the tension of the decorative sheet S.

Fourth Embodiment As shown in FIG. 4, a guide bar 7a is arranged 15 mm closer to the male die 2 than the parting line surface of the female die 1 to form the male die 2.
The mounting member 11 is provided from the lower surface of the
Mount the guide bar 10 slightly closer to the female die 1 than the parting line surface.

A mold for comparison with the first to fourth embodiments will be described. Comparative Example A first comparative example is shown in FIG. In this case, no guide bar is provided.

A second comparative example is shown in FIG. In this case, although the clamp bars 9a and 9b are provided, the guide bar is not provided. The third comparative example is shown in FIG.
This is a case where the distance from the parting line surface of the guide bar 7 is 5 mm in the first embodiment shown in (B).

The fourth comparative example is a case where the distance from the parting line surface of the guide bar 7 is 40 mm in the first embodiment shown in FIGS. 1 (A) and 1 (B). Comparative Results The results of actually molding products using the molds 1 and 2 of the first to fourth examples and the results of molding using the molds of comparative examples are shown. The injection conditions and the shape and size of the molded product are as follows.

2) As the injection condition painting sheet, the sheet having the layer structure shown in FIGS. 2 and 3 is used. Molded AS resin: Styrac AS clear made by Asahi Kasei, resin temperature: 220 ° C., mold temperature: 40 ° C, primary injection pressure: 70 kg / square cm, secondary injection pressure: 40 k
g / square cm, injection time: 7 seconds (filling: 3 seconds, holding pressure: 4
Seconds), cooling time: 30 seconds.

Molded product shape and dimensions As shown in FIG. 7, this is a 200 × 200 mm cylindrical plate having a thickness of 3 mm and a curved radius of curvature of 400 R, and the edge has a radius of 0.5 R over the entire circumference. R is formed.

During the transfer, the picture-added sheet was continuously rolled. The results of 100 shot molding are shown in Table 1.

[0028]

[Table 1] As is clear from Table 1, according to the present invention, the generation of wrinkles can be completely suppressed.

In the above embodiment, the guide bar 7 (see FIG.
As a reference), a linear one was used. However, FIG.
As shown in (A), when the product 106A has a curved surface and the curvature thereof is “r”, it is preferable to use the guide bar 7A having the same curvature as the curvature. That is, when the linear guide bar 7 is used, as shown in FIG.
Although wrinkles may occur on the decorative sheet S, wrinkles do not occur on the decorative sheet S as shown in FIG. 10B if the guide bar 7A has a curvature.

In the above embodiment, the case where the gate is provided in the mold (fixed mold, male mold 2) with which the surface of the painted sheet is in contact is described, but in the case of the tunnel gate, the movable parting line surface is used. It goes without saying that the guide bar may be arranged at a position protruding from the direction toward the fixed mold.

The guide bar may be made of any material as long as it does not deform or break due to the tension of the picture-added sheet, but metal such as iron is usually used. The guide bar is
Although it may be fixed so as not to rotate, it may be rotatably arranged around the shaft in order to reduce friction with the painting sheet.

[0032]

As described above, according to the present invention, since the drawing sheet is pressed toward either the male mold or the female mold, the tension in the running direction of the drawing sheet is increased. It is possible to prevent the occurrence of wrinkles on the surface of the product during injection molding, and because the picture sheet pressing member is arranged in the vicinity of the die, the picture position accuracy of the product can be accurately ensured.

[Brief description of drawings]

FIG. 1A is a perspective view of a first embodiment of the present invention, and FIG.
[FIG. 3] is a sectional view of the female mold of the embodiment.

FIG. 2 is a sectional view of a second embodiment of the present invention.

FIG. 3 is a sectional view of a third embodiment of the present invention.

FIG. 4 is a sectional view of a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view of a feeding device in comparison with an embodiment of the present invention.

FIG. 6 is a cross-sectional view of another feeding device compared with the embodiment of the present invention.

FIG. 7 is a perspective view of a product having a curved surface formed by using the molds of the first to fourth examples.

FIG. 8 is a layer cross-sectional view of a transfer painting sheet applied to this example.

FIG. 9 is a layer cross-sectional view of a laminated picture-added sheet applied to this example.

10A is a perspective view when a guide bar having a curvature is applied, FIG. 10B is a diagram showing a situation in which wrinkles are less likely to occur when a guide bar having a curvature is applied, and FIG. It is a figure which shows the situation where wrinkles occur frequently when the guide bar of FIG.

FIG. 11 is a schematic configuration diagram of a conventional injection molding simultaneous painting apparatus.

FIG. 12 is a perspective view of a product manufactured by conventional injection molding.

FIG. 13 is a perspective view of a conventional female mold.

FIG. 14 is a perspective view showing an inconvenience of a conventional product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Female type 2 ... Male type 5 ... Recessed surface 6 ... Gate 7, 7A ... Guide bar (pressing sheet pressing member) 8a, 8b ... Recess 9a, 9b ... Clamp bar S ... Painting sheet

Claims (2)

[Claims] 1. A painting sheet is arranged between molds composed of a female mold and a male mold, which are opposed to each other, and injection resin is poured from a gate while sandwiching the painting sheet, and molding and painting are performed by injection pressure. In the injection-molding simultaneous painting die that simultaneously performs, at least at the time of mold clamping, a painting sheet pressing member that pushes the painting sheet projected toward the male mold from the joint surface formed by the female mold and the male mold. , A painting sheet feeding device in a die for simultaneous painting with injection molding, which is provided in at least one position on the upstream side and the downstream side of the cavity. 2. The painting sheet in the injection-molding simultaneous painting die according to claim 1, wherein the painting sheet pressing member has a curvature substantially equal to a curvature of an outer shape of a product. Feeder.