JPH07276420A - In-mold transfer molding method and mold therefor - Google Patents

Abstract

PURPOSE:To provide an inmold transfer molding method with the capability of relieving the deformation of a transfer film even in the case where large steps exist, and integrally molding even an item with large steps. CONSTITUTION:Injection molding is performed after putting an insert 5 for defining an interstice 8 communicating to a molding space 3 between the insert and a core mold 2 In the recessed part 2a of the core mold 2 for forming step parts 3a with a predetermined dimension or more in the molding space 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides molding and heat transfer decoration to a molded product by injection molding with a film for heat transfer (hot stamp) interposed between a cavity mold and a core mold. The present invention relates to an in-mold transfer molding method capable of performing simultaneously, and an in-mold transfer molding die used for such in-mold transfer molding.

[0002]

2. Description of the Related Art In-mold transfer molding is also called simultaneous molding transfer, in which a transfer film having a printing layer on a base film is interposed between a cavity mold and a core mold, and the transfer film and the core mold are separated from each other. The resin material is injected into the molding space formed between the two parts, and in the in-mold transfer molding method, injection molding and surface decoration by thermal transfer to the molded product can be performed at the same time. Since the heat and pressure at the time of molding are used for thermal transfer as they are, there is no need to provide a new heat source or pressure source for thermal transfer, which saves manpower due to energy saving and process shortening, space saving, time saving etc. It can be expected to reduce costs significantly, and is used for example for molding interior parts for automobiles and panels for home electric appliances.

[0003]

However, the transfer film is three-dimensionally deformed according to the unevenness of the molded product, and has a large step like a holder part of a cigarette lighter in an instrument panel of an automobile, for example. In the part, the transfer film is in a deep drawing state,
It cannot extend along the outer shape of the molded product, causing defective molding and breakage of the transfer film.

Therefore, the parting line of the die has to be set to the extension limit of the transfer film, and for the step portion beyond that, the members are separately molded and adhered or fused. There is a problem that the number of molds and bonding jigs increases, the number of processes required for molding and bonding increases, and the manufacturing cost increases. In addition, it cannot be said that the adhesive portion will not be peeled off or fall off due to defective adhesion, and solving these problems has been an issue for improving the quality of the in-mold transfer molded product and reducing the cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems in conventional in-mold transfer molding.
Even if there is a large step in the molded product, the transfer film is not significantly deformed, and a product with a large step can be integrally molded, so that significant cost reduction and quality improvement can be achieved. An object of the present invention is to provide a mold transfer molding method and an in-mold transfer molding die.

[0006]

In the in-mold transfer molding method according to the present invention, a transfer film is interposed between a core mold and a cavity mold, and a resin material is interposed between the transfer film and the core mold. In in-mold transfer molding for injection, the molding space between the core mold and the core mold is formed in the recessed portion of the core mold that forms a step portion having a predetermined size or more in the molding space formed between the core mold and the cavity mold. The mold for injection molding according to the present invention is suitable for carrying out the above-mentioned in-mold transfer molding method. Between the core mold and a cavity mold that forms a molding space between the core mold and the core mold in a recessed portion of the core mold that forms a step portion having a predetermined size or more in the molding space. A nest inserted through a gap communicating with the molding space, a first nest fastening means for fastening the nest to the core mold side, and a second nest for fastening the nest to the cavity mold side. It is characterized in that it is configured to include a fastening means, characterized in that the above-mentioned configuration in the in-mold transfer molding method and in-mold transfer molding die is a means for solving the above-mentioned conventional problems. ..

[0007]

In the in-mold transfer molding method according to the present invention, the insert is inserted in the recessed portion of the core mold which forms the large step portion of the molding space which will force the transfer film to undergo deep deep drawing. Since the injection molding is performed above, the step size is reduced by the size of the nest, and the deep drawing deformation of the transfer film is alleviated, and the deformation of the transfer film falls within its deformability. Is prevented from breaking. Further, since the resin material enters the gap formed between the insert and the core mold during the injection molding, the step portion having the target size is integrally molded, so that another member is bonded or fused after molding. There is no need.

The in-mold transfer molding die according to the present invention has a core die, a cavity die, and a nest, and a first die for transferring the nest between the core die and the cavity die.
And the second nesting fastening means,
The structure is suitable for carrying out the in-mold transfer molding method according to the present invention. That is, by setting the transfer film in a state where the insert is fixed to the core mold side by the first nest fixing means, the transfer film can be smoothly mounted on the cavity mold side and the injection molding is completed. When the mold is opened later, the mold is opened while the mold is opened with the second mold fixing means fixed to the cavity mold side. At the same time when the mold is opened, the mold is separated from the molded product. This will speed up the process and improve the productivity of in-mold transfer molding.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of an in-mold transfer molding die according to the present invention. The in-mold transfer molding die 1 shown in the drawing has a core located on the lower side in the drawing. A mold 2 and a cavity mold 4 that forms a molding space 3 between the core mold 2 and a concave portion 2a of the core mold 2 that allows the molding space 3 to have large step portions 3a, 3a having a predetermined size or more. The core mold 2 and the cavity mold 4 are mainly composed of the inserted molds 5, and the core mold side and the cavity mold 4 are fixed to the core mold side and the cavity mold side, respectively, by the mechanism described later. Wearing means 6
(First nest fixing means) and cavity mold side nest fixing means 7 (second nest fixing means) are provided respectively, and the nest 5 is transferred between the core mold 2 and the cavity mold 4. It is like this.

In addition, in the central portion of the nest 5, as shown in FIG.
As shown in an enlarged view in (a), conical (mortar-shaped) fitting holes 5a and 5b opening toward the core mold 2 and the cavity mold 4 respectively are formed, and the nest 5 of the nest 5 is formed. Gaps 8 and 8 are formed around the core mold 2 and communicate with the molding space 3 to form part of the step portions 3a and 3a of the molding space 3. .

Further, the core mold 2 is provided with an ejector pin 9 for ejecting a molded product from the core mold 2 and an ejector plate 10 for operating the ejector pin 9 when the mold is opened after the molding is completed. .

The core mold side and cavity mold side nesting fastening means 6 and 7 have the same structure and are attached to the core mold 2 and the cavity mold 4, respectively, and are operated by hydraulic pressure. Drive cylinders 6a and 7a, core mold side and cavity mold side fitting rods 6b and 7b that are driven by the drive cylinders 6a and 7a and operate in the vertical direction in the figure, respectively.
As shown in (a), the core-type and cavity-type side lock nuts 6c are attached to the tips of the conical fitting rods 6b and 7b with some play.
And 7c, respectively.

The lock nuts 6c and 7c are shown in FIG.
It is a frustoconical ring shape as shown in (b),
A plurality of slits S provided on the periphery of the washer 6 are elastically expanded in the radial direction within a certain range, and the washer 6 attached to the tips of the fitting rods 6b and 7b.
The fitting rods 6b and 7b are prevented from falling off by the fitting rods 6d and 7d.
Based on the pushing operation of the
As a result, it expands in the radial direction.

That is, in the core mold side and cavity mold side nest fixing means 6 and 7, the fitting rod 6b or 7b together with the lock nut 6c or 7c is caused by the pushing operation of the drive cylinder 6a or 7a. After being fitted into the conical fitting hole 5a or 5b, the fitting rod 6b or 7b is further pushed by the pressing force of the drive cylinder 6a or 7a.
The lock nut 6c or 7c expands in the radial direction, whereby the insert 5 is fitted to the tip of the fitting rod 6b or 7b.

Then, as shown in FIG. 3, when one fitting rod 6b or 7b is fitted into the fitting hole 5a or 5b of the insert 5, the tips of the fitting rods 6b and 7b come into contact with each other, and the other Since the fitting rod 7b or 6b of the insert 5 is pushed out from the fitting hole 5b or 5a of the insert 5, the insert 5 is pushed by the driving cylinder 6a of the core-side insert fixing means 6 to push the core 2
Is fixed to the cavity mold 4 side by the pushing operation of the drive cylinder 7a of the cavity mold side nest fixing means 7.

Next, a procedure for performing in-mold transfer molding using the mold 1 having the above structure will be described with reference to FIGS. 4 to 9.

In the in-mold transfer molding die 1, the core die 2 is on the side of the fixed holder of the injection molding machine, and the cavity die 4 is provided.
Are attached to the movable holder side. Then, on the movable holder side, that is, on the side of the cavity mold 4, a transfer film roll 12 around which the transfer film 11 is wound, a winding roll 13 around which a used portion of the transfer film is wound when setting the transfer film 11, and a transfer film. A transfer film feeding device including guide rolls 14 and 15 for smoothly guiding 11 to the cavity mold 4 is provided.

FIG. 4 shows a state in which the mold is closed in preparation for the next molding after the end of the in-mold transfer molding.

That is, in the in-mold transfer molding method according to the present invention, as will be described later, the mold 5 is opened while being fixed to the cavity mold 4 side after molding. In order to move the insert 5 to the core mold 2, the molded product is molded, and then the mold is once closed as shown in FIG.

The cavity mold side nesting / fastening means 7
After turning off the hydraulic pressure of the drive cylinder 7a, the drive cylinder 6a of the core-type side nesting / fastening means 6 is pushed out to operate the core-type side fitting rod 6b and the lock nut 6c.
At the same time, the cavity mold side fitting rod 7b is pushed out from the fitting hole 5b of the nest 5 while being pushed into the fitting hole 5a of the nest 5 (see FIG. 3), thereby releasing the state in which the nest 5 is fixed to the cavity mold 4. At the same time, the nest 5 is fixed to the core mold 2 side. Then, the cavity type side drive cylinder 7a is retracted and actuated to further pull up the fitting rod 7b to the position shown in FIG. 2 (a).
Avoid interference between the cavity mold side fitting rod 7b and the transfer film 11.

Next, as shown in FIG. 5, the mold is opened again,
By rotating the winding roll 13 in the arrow direction,
The used portion of the transfer film 11 is moved to the right in the figure, and the unused portion is set in the cavity mold 4. At this time, through-holes (not shown) for inserting the cavity mold side fitting rod 7b when fixing the insert 5 to the cavity mold 4 are provided at predetermined positions at predetermined positions of the transfer film 11, The moving distance of the transfer film 11 is detected by counting the number of rotations of the guide roll 13 of the transfer film feeding device, and the through holes are aligned with each other.

Then, after the mold is closed as shown in FIG. 6, a resin material is injected from the core mold 2 side into the molding space 3 formed between the core mold 2 and the cavity mold 4. .

As a result, the molding space 3 is filled with the resin, and the molded product 16 is molded in the molding space.
The print layer of the transfer film 11 is peeled from the base film by the heat and pressure during the injection molding and is transferred to the surface of the molded product, so that the transfer and decoration of the molded product 16 are simultaneously performed.

At this time, the insert 5 is fixed to the recessed portion 2a of the core mold 2 as described above, which is in a raised bottom state so that the deep drawing state of the transfer film 11 is alleviated, and the transfer film 11 is relaxed. Since the deformation of No. 11 is within the elongation limit, defective molding occurs,
The transfer film 11 does not break.
Further, since a gap 8 is formed around the nest 5 with the core mold 2 (see FIG. 2A), the resin material enters the gap 8 during injection molding, A step portion having a predetermined size is integrally molded.

After completion of the injection molding, the mold insert 5 is moved from the core mold 2 to the cavity mold 4 side before opening the mold. That is, after the hydraulic pressure of the core mold side drive cylinder 6a is cut off, the drive cylinder 7a of the cavity mold side nest fixing means 7 is pushed out to push out the core mold side fitting rod 6b from the fitting hole 5a of the nest 5. By pressing the cavity mold side fitting rod 7b together with the lock nut 7c into the fitting hole 5b of the nest 5, the nest 5 is fitted to the tip of the cavity mold side fitting rod 7b,
As shown in FIG. 3, the nest 5 is fixed to the cavity mold 4 side.

Then, after the mold is opened as shown in FIG. 7, the molded product 16 is ejected from the core mold 2 by the ejector plate 10 and the ejector pin 9 as shown in FIG. As shown in b), it is possible to obtain a molded product 16 which has a large step portion 16a and whose surface portion (cavity mold 4 side) is decorated with the printing layer 17. The molded product 1
In FIG. 6, the printing layer 17 does not reach the bottom of the step 16a, but reaches the parting line of the mold 1.

After that, the mold 1 is closed as shown in FIG. 4, and the insert 5 is moved from the cavity mold 4 side to the core mold 2 side to prepare for the next in-mold transfer molding.

[0029]

As described above, in the in-mold transfer molding method according to the present invention, the recessed portion of the core mold for forming a large step portion of the molding space that will force severe deep drawing deformation of the transfer film. Since the injection molding is performed after inserting the nest, the deep drawing deformation of the transfer film is alleviated within its deformability, and the resin film is smoothly deformed according to the injection of the resin material. It is possible to prevent molding failure and breakage of the transfer film.
In addition, since a gap communicating with the molding space is formed between the insert and the core mold, the resin material enters the gap during injection molding to integrally form a step portion having a desired size. It is possible to improve the quality of the in-mold transfer molded product and to reduce the cost, which is an extremely excellent effect.

The in-mold transfer molding die according to the present invention further comprises a core die, a cavity die, a nest, a first nest fastening means for fastening the nest to the core die side, and the nest. And a second nest fastening means for fastening the nest to the cavity mold side. Therefore, when the transfer film is set, the nest is fastened to the core mold side, and when the mold is opened, the nest is fitted to the cavity mold side. By fixing to the above, the excellent effect that the in-mold transfer molding according to the present invention can be smoothly and rationally carried out is brought about.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an in-mold transfer molding die according to the present invention.

2 (a) is an enlarged view showing a structure of a nest and a nest fixing means in the in-mold transfer molding die shown in FIG. 1. FIG. (B) It is a perspective view which shows the shape of the lock nut shown to Fig.2 (a).

FIG. 3 is a cross-sectional view illustrating a delivery state of a nest by first and second nest fastening means of the in-mold transfer molding die shown in FIG.

FIG. 4 is a schematic diagram illustrating a mold closing and nest moving process in an in-mold transfer molding process using the molding die shown in FIG.

FIG. 5 is a schematic view illustrating a mold opening and a transfer film setting process in an in-mold transfer molding process.

FIG. 6 is a schematic diagram illustrating a mold closing and injection process in an in-mold transfer molding process.

FIG. 7 is a schematic diagram illustrating a mold opening step in an in-mold transfer molding step.

FIG. 8 is a schematic view illustrating a step of taking out a molded product in the in-mold transfer molding step.

9A and 9B are a perspective view and a vertical cross-sectional view, respectively, showing the shape of a molded product.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Mold for in-mold transfer molding 2 Core type 2a Recessed part 3 Molding space 3a Step part 4 Cavity type 5 Nesting 6 Core type side nesting fastening means (first nesting fastening means) 6a Drive cylinder 6b Fitting rod 6c Lock nut 7 Cavity type side nesting fastening means (second nesting fastening means) 7a Drive cylinder 7b Fitting rod 7c Lock nut 8 Gap 11 Transfer film

Claims (4)

[Claims] 1. In-mold transfer molding in which a transfer film is interposed between a core mold and a cavity mold, and a resin material is injected between the transfer film and the core mold, wherein the core mold and the cavity mold are Injecting after inserting a nest forming a gap communicating with the molding space with the core mold in the recessed part of the core mold that forms a step portion with a predetermined size or more in the molding space formed between An in-mold transfer molding method comprising molding. 2. The in-mold transfer molding method according to claim 1, wherein after the injection molding is completed, the mold is opened in a state where the insert is fixed to the cavity mold side. 3. A core mold, a cavity mold that forms a molding space between the core mold, and the core mold in a recessed portion of the core mold that forms a step portion having a predetermined size or more in the molding space. A nest inserted between the mold and the molding space, a first nest fastening means for fastening the nest to the core mold side, and a second nest fastening the nest to the cavity mold side. A mold for in-mold transfer molding, comprising: 4. A nesting fastening means comprises a fitting rod having a conical tip end fitted into a conical fitting hole formed in the nest, and a drive cylinder for pushing and pulling the fitting rod. And a lock nut interposed between the conical tip portion of the fitting rod and the conical fitting hole of the nest so as to fit the tip portion of the rod into the fitting hole of the nest. The mold for in-mold transfer molding according to claim 3.