JPS641050Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field The present invention relates to a mold for a transfer molding device.

(B) Prior Art A transfer molding device is a device that inserts a plastic film with a printed design between molds and transfers the design onto the molded product at the same time as molding. In the case of transferring a design only to the flat surface of a molded product, a mold as shown in FIG. 1 has conventionally been used. That is, the fixed mold 10 is provided with a carved portion 14 that is open on the parting surface 12 side, while the movable mold 16 is
The parting surface 18 is uniformly flat. Such a fixed mold 10 and a movable mold 16,
The mold is closed with the transfer film sandwiched between the parting surfaces 12 and 18, and the carved part 14 of the fixed mold 10 and the parting surface 18 of the movable mold 16 are removed.
When the molten resin is injected into the cavity formed by this method, the pattern on the transfer film is transferred simultaneously with the molding, and a molded product 20 as shown in FIG. 2, for example, is obtained. The pattern is transferred to a flat surface 20a marked with hatching in FIG. However, when transfer molding is performed using the mold of such conventional transfer molding equipment, the transfer film comes into contact with the high-temperature molten resin during injection and stretches. Wrinkles occurred in the pattern around the periphery of the image 20a, and the desired transfer could not be performed.

(c) Purpose of the invention The purpose of the invention is to obtain a mold for a transfer molding device that can transfer a design onto a flat surface without causing wrinkles in the design.

(d) Structure of the invention The invention is based on a mold that has a very shallow flat recess that allows the transfer film to stretch without causing wrinkles when it is stretched, on the side of the mold that contacts the flat surface of the molded product. By providing this, the above objective is achieved. That is, in the present invention, a transfer film with a pattern is sandwiched between one mold having an engraved part corresponding to the shape of the molded product and the other mold,
It is intended for the mold of a transfer molding device that transfers the design on the transfer film onto the flat surface of the molded product at the same time as molding, and peels off the part of the transfer film other than the design from the molded product when the mold is opened. The other mold is provided with a flat recess at a position corresponding to the flat surface of the molded product, and the depth of this recess from the parting surface is set to a size that can absorb the elongation due to thermal expansion of the transfer film during molding. It is characterized by what it did.

With this configuration, the elongation that occurs in the transfer film during molding is absorbed by the recessed portions, and wrinkles are prevented from forming in the design.

(E) Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 3 to 5 of the accompanying drawings.

The parting surface 32 of the fixed mold 30 is provided with a carved portion 34 of a predetermined shape that is open to the parting surface 32 side. Note that in this embodiment, the carved portions 34 are provided at four locations, so that there are four carved portions 34.
The movable mold 36 is provided with a recess 38 having a depth t from the parting surface 37 at a position corresponding to the carved part 34. The depth t is uniform over the entire surface of the recess 38 (that is, the bottom of the recess 38 is flat), and its value varies depending on the size of the molded product, the thickness of the transfer film, etc. It is 0.1~0.5mm. The fixed mold 30 is provided with a clamp 40 for fixing the transfer film, and the movable mold 36 is provided with a guide bar 42 for guiding the transfer film.

Transfer molding using this mold is performed as follows. First, a transfer film is fed and positioned at a predetermined position between the molds by a film positioning device (not shown) provided on a movable platen to which the movable mold 36 is attached. Next, the movable mold 36 is moved forward together with the movable platen, and the transfer film is sandwiched between the parting surface 37 of the movable mold 36 and the parting surface 32 of the fixed mold 30. The transfer film is fixed by a clamp 40 that sinks into the fixed mold 30 while being pressed by a spring. Next, molten resin is injected from the fixed mold 30 side into the cavity formed by the carved part 34 and the recessed part 38, and the pattern on the transfer film is transferred simultaneously with the molding. At this time, the transfer film contacts the high-temperature molten resin and stretches, but since it is pushed into the movable mold 36 by the dimension t, the stretching is absorbed and wrinkles do not occur. Next, the mold is opened, and the transfer film is pulled by the guide bar 42 and moves together with the movable mold 36, and is peeled off from the molded product in the carved part 34 of the fixed mold 30. Then,
The molded part is ejected. This completes one molding cycle, and the same molding cycle is repeated thereafter. 1 of 50 molded products molded as described above
An example is shown in FIG. In FIG. 5, the hatched surface is the flat surface 50a to which the design is transferred. In this case, the end surface 50b of the molded product 50 is also transferred by the dimension t, but as mentioned above, the dimension t is 0.1 to 0.5 mm, which is a very small value, so it is essentially flat. It is possible to obtain the same effect as when the pattern is transferred only to the surface 50a. Furthermore, since the transfer film is stretched by an amount corresponding to the t dimension, wrinkles do not occur around the pattern.

(F) Effect of the invention As explained above, in the mold of the transfer molding apparatus according to the invention, one mold has a flat surface on which the pattern of the molded product to be transferred is located on the parting surface side. The other mold has a flat recessed part with a depth that can absorb the elongation due to thermal expansion of the transfer film during molding, so wrinkles can be avoided. The design can be transferred onto a flat surface without any generation.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a mold of a conventional transfer molding device;
Fig. 2 is a diagram showing a molded product transfer-molded by a mold of a conventional transfer molding device, Fig. 3 is a diagram showing a mold of a transfer molding device according to the present invention, and Fig. 4 is similar to Fig. 3. FIG. 5 is a view showing a mold of the transfer molding apparatus shown in FIG. 30...Fixed type, 32...Parting surface, 3
4... Engraved part, 36... Movable mold, 37... Parting surface, 38... Recessed part, 50... Molded product, 5
0a...Flat surface.

Claims (1)

[Claim for Utility Model Registration] A transfer film with a pattern is sandwiched between one mold having an engraved part corresponding to the shape of the molded product and the other mold, and the transfer film is placed on the transfer film at the same time as molding. In the mold of a transfer molding device that transfers the design onto the flat surface of the molded product and then peels off the portion of the transfer film other than the design from the molded product when the mold is opened, the other mold is used to transfer the design onto the flat surface of the molded product. A flat recess is provided at a position corresponding to the parting surface, and the depth of the recess from the parting surface is set to a size that can absorb elongation due to thermal expansion of the transfer film during molding. Mold.