JP2003200464A - Injection molding mold for molding with film and method for producing molding with film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a injection molding mold for a molding with a film which is easy of demolding and can prevent the deformation of the molding during the demolding. <P>SOLUTION: In the injection molding mold 1, a resin film is arranged between paired molds provided with a cavity side mold 3 having a recessed part 3a in the shape of a final product and a core side mold 4 closing the recessed part 3a, and the molding with the film is molded. The core side mold 4 has a base plate 5 integrated with a gate 8b for injecting a molten resin and a striper plate 6 which is arranged on the recessed part 3a side of the base plate 5 and can move in the mold opening direction. After the core side mold 4 is separated from the cavity side mold 3 for mold opening, the striper plate 6 is moved to the recessed part 3a side to be separated from the base plate 5, and the molding with the film is detached from the core side mold 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die for a molded article with a film, in which a resin film is placed in a pair of molds and a molten resin is injection-molded on the resin film. The present invention relates to an injection-molding die for a molded product with a film that can be easily taken out from a mold and a method for producing a molded product with a film using this mold.

[0002]

2. Description of the Related Art As a resin molded product having a plurality of protrusions such as a push button sheet of a mobile phone, it has a shape in which a plurality of protrusions 21 are connected at a base 22 as shown in FIG. The outer surface of the protrusion 21 and the base 22
It is known that a molded product with a film is formed in which the resin film 23 is continuous and the resin 24 is filled inside each of the protrusions 21 and characters are printed on the resin film 23 on the top 21a of the protrusion 21. There is.

In order to manufacture such a molded article with a film, an injection molding die 20 as shown in FIG. 8 is used. For example, in Japanese Patent No. 3136388, a cavity side metal having a cavity recess 25 is used. The resin film 23 preformed according to the plate shape or the product shape is arranged between the mold 26 and the core-side mold 29 on which the spool 27, the gate portion 28, etc. are arranged, and the molten resin 24 is discharged from the gate portion 28. By injecting, the resin film 23 is stretched and deformed by the heat and injection pressure of the molten resin, and the resin film 2 is closely attached to the inner surface of the cavity recess 25.
It is manufactured by integrating 3 and the resin 24.

In such an injection mold 20, the cavity side mold 2 is used to take out a molded product from the mold after molding.
6 is opened from the core side mold 29, and then the resin film 2
An operator grips a part of 3 and pulls out the protruding portion 21 from the cavity recess 25, or blows compressed air from the cavity side mold 26 onto the resin film 23 to take out the resin film 23.

Incidentally, in the case of an injection-molded product which does not use the resin film 23, a protrusion pin or the like is generally provided in the mold, and the molded product is directly taken out by the protrusion pin.

[0006]

However, in such an injection molding die 20, when a molded product is taken out, a pressing force and a peeling force are locally applied, so that the molding product is completely cured immediately after the mold is opened. There has been a problem that the former molded article which is easily deformed is deformed by its local force.

Particularly in the case of a film-formed molded product having a plurality of protrusions 21, all the protrusions 21 must be taken out from the cavity recesses 25 of the mold, and the resin film 23 is taken out while uniformly applying a force. It had a problem that it was not easy.

Therefore, an object of the present invention is to provide an injection mold for a molded product with a film, in which the molded product can be easily taken out and the deformation of the molded product can be prevented at the time of taking it out.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a cavity side mold having a recess having a final product shape and a core side mold closing the recess. A resin film is disposed between a pair of molds provided, and a molten resin is injected to inject the molten resin and the resin film into one piece while closely adhering the resin film to the wall surface of the recess. Molding die,
The core-side mold has a base plate integrally formed with a gate part for injecting the molten resin, and a stripper plate arranged on the recess side of the base plate and movable in the mold opening direction. After the mold is separated from the cavity side mold and the mold is opened, the stripper plate is moved to the recess side and separated from the base plate.

The invention described in claim 2 is the same as claim 1.
In addition to the configuration described in, the stripper plate,
It is characterized in that it has a convex portion facing the peripheral edge of the opening of the concave portion.

Further, in the invention described in claim 3, in addition to the structure described in claim 2, the height of the convex portion is 20% to 70% of the thickness of the resin film. I am trying.

Further, in the invention of the manufacturing method according to the fourth aspect, a resin film is provided between a pair of molds provided with a cavity side mold having a recess of a final product shape and a core side mold closing the recess. A method for producing a molded article with a film, wherein the molten resin and the resin film are integrated while closely contacting the resin film with the wall surface of the recess by injecting a molten resin, wherein the core-side mold is A base plate integrated with a gate portion for injecting the molten resin, and a stripper plate arranged on the concave side of the base plate and movable in the mold opening direction, and injecting the molten resin from the gate portion A step of molding the film-formed molded product into a final product shape; a step of separating the core side mold from the cavity side mold to open the mold; and the stripper plate It is characterized by comprising a step of moving the parts side by cutting the gate portion by separating the base plate removed molded article with the film from the core side mold, a.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
It will be described with reference to the drawings.

FIG. 1 shows an injection molding die according to an embodiment of the present invention.

The injection molding die 1 comprises a cavity side die 3 and a core side die 4, and the cavity side die 3 is shown in FIG.
The outer surface 3 that is continuous between the recesses 3a having the final product shape corresponding to the plurality of protrusions 21 as shown in FIG.
b, the wall surface 3c of the recess 3a has the shape of the outer surface of the final product.

The core-side mold 4 includes a base plate 5 connected to the molten resin supply side, and a stripper plate 6 adjacent to the base plate 5 and facing the cavity-side mold 3.
And have. Further, the core side mold 4 is accommodated in a through hole 7 penetrating the base plate 5 and the stripper plate 6, one end of which is locked to the base plate 5 to be integrated, and the other end of which is a cavity. It has a gate bush 8 exposed on the side of the recess 3a of the side die 3. The outer surface 6c of the stripper plate 6 and the end surface 8c of the gate bush 8 facing the recess 3a correspond to the bottom shape of the product.

Then, the wall surface 3c of the recess 3a of the cavity side mold 3 and the stripper plate 6 of the core side mold 4 are used.
Outer surface 6c, through hole 7 and end surface 8 of gate bush 8
The space surrounded by c is filled with the filling resin 2.

FIG. 2 is a sectional view of the injection molding die 1 in the vicinity of the gate bush 8.

The gate bush 8 has a spool portion 8a and a gate portion 8b which are continuous from the molten resin supply side, one of which is a columnar body 11 protruding from the base plate 5 in a columnar shape, and one end face 8c thereof. At gate 8b
Are arranged. Also, the other end 8e on the supply side
A flange portion 8f locked to the base plate 5 is provided on the outer periphery on the side. The through hole 7 accommodating the gate bush 8 is provided so as to be oriented in the mold opening direction, and prevents molten resin from entering between the gate bush 8 and the through hole 7 and allows gas to enter. Width, for example 5-25μ
A radial gap 13 having a width of about m is provided to communicate the outside of the stripper plate 6 with the outside of the base plate 5.

Further, in this injection molding die 1, the through hole 7
On the outer surface 6c of the outer stripper plate 6, an annularly continuous convex portion 6a is provided so as to face the opening peripheral edge portion 3e of the concave portion 3a of the cavity side mold 3. This convex portion 6a
The preform molding 10 made of a resin film is firmly sandwiched between and the opening peripheral edge portion 3e of the cavity side mold 3.

In this convex portion 6a, it is preferable that the width of the sandwiching portion for sandwiching the preform molded body 10 so as to face the opening peripheral edge portion 3e is set to 2 mm or less. Opening peripheral edge 3e
This is because the preform molded body 10 can be more uniformly sandwiched by. Here, the convex portion 6a further has a width from the inside to the outside of the opening peripheral edge portion 3e of the concave portion 3a.

The height of the convex portion 6a is preferably 20% to 70% of the thickness of the resin film. When this height exceeds 70% of the thickness of the resin film, the cavity-side mold 3 is not formed in a portion other than between the convex portion 6a and the opening peripheral edge portion 3e.
The gap between the stripper plate 6 and the stripper plate 6 becomes large, and the resin film becomes slack during molding and easily deforms into a waveform. On the other hand, when the thickness of the resin film is less than 20%, when the thickness of the preform molded body 10 becomes uneven in the previous step such as printing or molding, the thickness between the convex portion 6a and the opening peripheral edge portion 3e is increased. The preform molded body 10 cannot be firmly held, and the filled resin 2 easily flows out.

In this injection molding die 1, a cavity side die 3 is formed by a guide member, a driving device, etc. not shown.
And the stripper plate 6 are movable in the mold opening direction.

A method for manufacturing a push-button sheet for a mobile phone, which is a molded product with a film, by using the injection molding die 1 having the above-mentioned structure will be described as an example.

Here, the injection molding die 1 is manufactured by injecting a molten resin and integrating it with a resin film sandwiched between the cavity side die 3 and the core side die 4.

Examples of the resin film used in this manufacturing method include films made of polyethylene terephthalate, polyurethane, polyamide, polycarbonate, or alloys thereof.

For this resin film, it is preferable to use a preform molded body 10 which has been preformed into a final product shape in advance. This is because it is not necessary to heat the molten resin during injection and to stretch and deform the resin film during injection, and it is possible to prevent defective molding due to deformation of the resin film. This preforming process is a vacuum forming process that is usually used to form irregularities on a resin film,
It may be performed by a molding method such as pressure air vacuum molding.

On the other hand, as the filling resin 2, polyurethane, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyacrylonitrile butadiene styrene, etc., which have fluidity suitable for injection molding in a molten state, are used. It is desirable to use a resin that is compatible with the film.

Therefore, first, a temperature adjusting means (not shown) is used for the injection mold 1 to adjust the temperature to a temperature suitable for injection molding.

The temperature of the injection molding die 1 may be such that the fluidity of the molten resin can be secured as a whole, but when the preform molding 10 is used, the cavity side die 3 having the concave portion 3a is made of resin. It is preferable to set the temperature below the heat distortion temperature of the film. Since it is preformed into the final product shape in advance, it is not necessary to stretch and deform the resin film at the time of injection, and it is not necessary to excessively heat the resin film.

When the above-mentioned materials are used as the filling resin and the resin film, for example, the temperature of the cavity side mold 3 is set to preferably 40 ° C. or higher and lower than 80 ° C., more preferably 50 ° C. or higher and 60 ° C. or lower. .

On the other hand, the core side mold part 4 may be set to a temperature at which the fluidity of the molten resin can be ensured, as in the case of the conventionally used injection molding mold, and the push button sheet of a mobile phone is used. When the protrusion 21 is small as described above, it is possible to set the same temperature as that of the cavity side mold 3. When the core side mold part 4 is set to the same temperature as the cavity side mold 3, the gate bush 8 may be set to a temperature at which the fluidity of the molten resin and the like can be secured.

When using the above-mentioned filling resin and resin film, for example, the temperature of the core side mold 4 is set to 90 ° C. or higher, more preferably 100 to 120 ° C., and the temperature of the cavity side mold 3 is preferably 40. It is possible to set the temperature to not less than 80 ° C and more preferably not less than 50 ° C and not more than 60 ° C.

The temperature of such an injection molding die 1 is preferably set before injection molding and kept constant during and after injection molding.

Next, as shown in FIG. 3, the injection-molding die 1 whose temperature has been set as described above is opened at the parting line between the cavity-side die 3 and the core-side die 4 as shown in FIG. ,
Preform molded body 10 previously molded into a final product shape
The plurality of protruding parts of the cavity side mold 3
Insert into a and set. At this time, since the preform molded body 10 is molded into the final product shape, the recess 3a
Is arranged along the wall surface 3c.

The preform molded body 10 is clamped in a state where it is set in the cavity side mold 3, and the preform molded body 10 has the opening 6a of the stripper plate 6 and the peripheral edge of the recess 3a of the cavity side mold 3. The preform molded body 10 is sandwiched between the surface of 3e and the surface of 3e, and the preform molded body 10 and the recess 3a are fully adhered to each other.

Thereafter, the molten resin is supplied to the injection molding die 1 from a nozzle of a resin supply portion (not shown), and the molten resin is fed into the recess 3a of the cavity side die 3 through the spool portion 8a and the gate portion 8b in the gate bush 8. Inject. When the injection pressure and heat of the molten resin are applied to one surface side of the preform molded body 10, the other surface side is brought into close contact with the outer surface 3b of the recess 3a of the cavity side mold 3 and the wall surface 3 of the recess 3a.
An outer surface that completely matches the slight irregularities of the display portion and the like provided in c is formed.

At the time of this injection molding, the cavity side mold 3
The recess 3a is sealed between the core and the mold 4 on the core side.
The gas in the recess 3a is discharged to the outside from the gap 13 between the gate bush 8 and the through hole 7.

The injection is terminated with the molten resin filled in the recess 3a, and the filling resin 2 is solidified to such an extent that it can be taken out. At this time, the cavity side mold 3 is 40 ° C. or higher 8
Since the resin film is set to less than 0 ° C. and is solidified to the extent that the outer surface shape can be maintained, the filling resin 2 may not be completely solidified.

In order to take out the film-formed molded product from the injection molding mold 1, first, with the base plate 5 and the stripper plate 6 integrated, the cavity side mold 3 is moved in the mold opening direction, and the core is moved. The mold is opened at the parting line between the side mold 4. Thereby, as shown in FIG. 4, the molded product with a film is taken out from the recess 3a of the cavity side mold 3 in a state where the molten resin in the gate portion 8b and the filling resin 2 in the recess 3a are connected.

At this time, the gate portion 8 of the gate bush 8
b and the end surface 8c, and the recess 3 of the stripper plate 6
The outer surface 6c facing a is in contact with the filling resin 2 of the film-formed molded product, and the stripper plate 6
The convex portion 6a is in contact with the resin film of the film-formed molded product.

Next, when the stripper plate 6 is moved in the mold opening direction and separated from the base plate 5, the gate portion 8b and the outer surface 8c of the gate bush 8 and the outer surface 6c and the convex portion 6a of the stripper plate 6 are separated. Be relatively far apart. As a result, the filling resin 2 of the molded product with a film is pressed by the convex portion 6a of the stripper plate 6 and the resin film of the molded product with a film is pressed by the convex portion 6a, and as shown in FIG. The filling resin 2 of the product and the molten resin in the gate portion 8b are separated and cut at the position of the gate portion 8b. As a result, the molded product with the film falls freely from the stripper plate 6 by the action of gravity, and is automatically removed from the injection molding die 1.

According to such an injection molding die 1, the gate bush 8 having the gate portion 8b in contact with the filling resin 2 in the concave portion 3a is locked at a predetermined position of the base plate 5 and integrated, and the stripper plate is formed. Since 6 has an outer surface 6c in contact with the concave portion 3a and is arranged so as to be movable in the mold opening direction, it is possible to simply move the stripper plate 6 after the cavity side mold 3 is opened, and then the molded product with a film. The molded product with film can be removed from the injection mold 1 at the same time when the filling resin 2 and the molten resin in the gate portion 8b are cut, and the molded product with film can be taken out easily.

Moreover, the outer surface 6 of the stripper plate 6
Since c has a convex portion 6a, the resin film of the molded product with a film can be pressed by the convex portion 6a at the same time as the resin film of the molded product with a film can be pressed by the convex portion 6a at the time of removal. It is possible to press with the plate 6, it is difficult to apply a local force, and it is possible to prevent deformation of the film-attached molded product at the time of removal. Further, since the convex portion 6a of the stripper plate 6 is provided at a position facing the opening peripheral edge portion 3e of the concave portion 3a, the resin film is sufficiently compressed between the cavity side mold 3 and the convex portion 6a. It can be sandwiched, and the convex portion 6a and the resin film can be brought into close contact with each other. Therefore, the molten resin does not enter between the convex portion 6a and the resin film during injection, and the filling resin 2 does not adhere to the resin film around the concave portion 3a. Therefore, at the time of removal, the resin film can be pressed in a state in which the convex portion 6a is in direct contact with the resin film around the concave portion 3a, and the force for pressing the filling resin 2 with the convex portion 6a and the resin film around the concave portion 3a. It is possible to equalize the force of pressing with the convex portion 6a, and it is possible to reliably prevent the deformation of the product.

Furthermore, since the stripper plate 6 corresponding to the entire circumference of the concave portion 3a is provided with the continuous annular convex portion 6a, the convex portion 6a can be brought into close contact with the resin film around the concave portion 3a, The resin film around each recess 3a can be pressed completely and uniformly, and the product deformation can be prevented more reliably.

Further, in the above-described embodiment, the gate bush 8 has a pillar portion provided with the gate portion 8b, and is a separate member cylindrical body 11 which is engaged with and integrated with the base plate 5.
However, it may be a pillar portion integrally formed with the base plate 5 in a pillar shape. Further, the amount of protrusion of the pillar portion can be changed as appropriate, and the entire pillar portion may be housed in the through hole 7, and when the stripper plate 6 moves to the core side mold 3 side, the pillar portion penetrates the through hole. As long as 7 does not come off, a part of the pillar may be housed. Further, the gate portion 8b may be directly provided on the surface of the base plate 5 without providing the pillar portion on the base plate 5. In this case, since the gate portion 8b needs to be in contact with the filling resin 2, a through hole, an opening or the like is provided at a position of the stripper plate 6 corresponding to the gate portion 8b. In this way, by appropriately selecting the pillar portion, the relative position of the gate portion 8b and the stripper plate 6 in the mold opening direction can be adjusted, and the position of the gate portion 8b can be set according to the shapes of various film-formed molded products. can do.

Further, although the example of manufacturing the push button sheet of the mobile phone has been described, it may be the manufacture of another film-formed molded product, and a metal for molding a film-formed molded product having at least one protruding portion 21. It can also be applied to molds.

Further, as for the surface shape of the convex portion 6a for sandwiching the resin film, as shown in FIG. 6, for example, a part of the surface in contact with the resin film is roughened to form fine irregularities 6d.
By providing the above, it is possible to appropriately change such that the resin film can be sandwiched more reliably.

[0049]

As described above, according to the first aspect of the invention, the core-side mold is arranged on the base plate having the integrated gate portion for injecting the molten resin, and on the concave side of the base plate. Since it has a stripper plate that is movable in the mold opening direction, and the core side mold is separated from the cavity side mold to open the mold, the stripper plate is moved to the recess side so that it can be separated from the base plate. The molten resin and the filled resin in the gate portion can be separated and cut. Therefore, the molded product with a film can be automatically removed only by moving the mold and the stripper plate on the cavity side, and the removal is easy.

Further, according to the invention as defined in claim 2 or 3, since the stripper plate has the convex portion facing the opening peripheral portion of the concave portion, when the gate is cut, the filling resin is filled with the filling resin. Since the resin film can be pressed by the convex portion at the same time as being pressed by the outer surface of, the entire molded product with a film can be pressed and taken out in addition to the effect of the first aspect. Therefore, it is possible to prevent deformation of the molded product without locally pressing the molded product at the time of taking out.

Further, even if the resin film has a non-uniform thickness, the resin film can be sufficiently compressed and sandwiched in the convex portions, and the support portion and the resin film can be brought into close contact with each other. Therefore, the molten resin does not enter between the support portion and the resin film during injection, and the filled resin does not adhere to the resin film around the recess. Therefore, the resin film can be pressed in a state where the convex portion is in direct contact with the resin film around the concave portion, and the force for pressing the filling resin with the mold surface and the force for pressing the resin film around the concave portion with the supporting portion. Can be made uniform, and deformation of the product can be reliably prevented.

According to the invention of the manufacturing method described in claim 4, the core-side mold has a base plate integrally formed with a gate part for injecting a molten resin, and a mold opening provided on the concave side of the base plate. With a stripper plate that can be moved in any direction, and a step of injecting molten resin from the gate to mold the molded product with film into the final product shape, and separating the core side mold from the cavity side mold to open the mold. Since it has a step and a step of moving the stripper plate to the recess side and separating it from the base plate to cut the gate part and remove the film-formed molded product from the core side mold, separate the molten resin and the filling resin in the gate part from each other. Can be cut. Therefore, the molded product with a film can be automatically removed only by moving the mold and the stripper plate on the cavity side, and the removal is easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an injection molding die used in a manufacturing method according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the vicinity of a gate bush of the injection molding die of FIG.

FIG. 3 is a cross-sectional view showing a state in which a preform molded body is arranged in the injection mold of FIG.

FIG. 4 is a cross-sectional view showing a state in which a cavity side mold of the injection molding mold of FIG. 1 after molding is opened.

5 is a cross-sectional view showing a state where the stripper plate of the injection molding die of FIG. 1 after molding is opened.

FIG. 6 is a cross-sectional view showing a surface shape of a convex portion provided in the core side mold according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view of a conventional molded product with a film having a plurality of protrusions.

FIG. 8 is a cross-sectional view illustrating a process of manufacturing a film-formed molded product using a conventional injection molding die.

[Explanation of symbols]

1 injection mold 2 Filling resin 3 Cavity side mold 3a recess 4 Core side mold 5 base plate 6 stripper plate 6a convex part 6c outer surface 6d unevenness 8 gate bush 8a spool part 8b Gate part 10 Preform molding 11 cylindrical body

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F202 AD08 AG03 CA11 CB13 CK42                       CM07                 4F206 AD08 AG03 JA07 JB13 JN41                       JQ81

Claims (4)

[Claims] 1. A resin film is disposed between a pair of molds including a mold on the cavity side having a recess having a final product shape and a mold on the core side for closing the recess, and the molten resin is injected to form the resin. An injection molding die for a molded article with a film, wherein the molten resin and the resin film are integrated while closely adhering a film to the wall surface of the recess, wherein the core-side die has a gate portion for injecting the molten resin. It has an integrated base plate and a stripper plate that is arranged on the concave side of the base plate and is movable in the mold opening direction, and after the core side mold is separated from the cavity side mold and the mold is opened, An injection molding die for a molded product with a film, which has a structure in which a stripper plate is moved to the recess side and can be separated from the base plate. 2. The injection-molding die for a molded article with a film according to claim 1, wherein the stripper plate has a convex portion that faces an opening peripheral edge portion of the concave portion. 3. The height of the convex portion is 20% to 70% of the thickness of the resin film.
An injection molding die for a molded article with a film according to. 4. A resin film is placed between a pair of molds including a mold on the cavity side having a recess in the shape of the final product and a mold on the core side to close the recess, and the molten resin is injected to form the resin. A method for manufacturing a molded article with a film, wherein the molten resin and the resin film are integrated while closely contacting a film to the wall surface of the recess, wherein the core-side mold has a gate portion for injecting the molten resin integrally. And a stripper plate that is arranged on the concave side of the base plate and is movable in the mold opening direction. The molten resin is injected from the gate portion to mold the film-formed molded product into the final product shape. A step of separating the core-side mold from the cavity-side mold and opening the mold; and sliding the stripper plate toward the recess side to form the base plate. Method of producing a film with a molded article, characterized in that and a step of removing the by cutting the gate portion and the film with the molded article from said core mold half by pulling apart.