JPH03253317A - Method for simultaneous in-mold decorating and mold and transfer foil used therefor - Google Patents

Abstract

PURPOSE:To make it possible to transfer the transfer layer of transfer foil by the heat and pressure of molten resin by a method wherein the injected molten resin is fed from the cavity side through a hole to the core side in a runner so as to locate the transfer layer side in order to form a molded item by transferring the transfer layer to the exterior side of the molded item at the solidification of the molten resin. CONSTITUTION:Resin is injected from the nozzle of an injection machine to a sprue part 25. The heated resin under molten state is pushed out of the sprue part 25 to a runner 13 and fed through a sprue hole 46 to the bonding layer 45 side of transfer foil 40 so as to push the transfer foil 40 against a cavity-retainer plate 22, run through the runner 13 and a gate 12 and reach a cavity. Accordingly, the transfer foil 40 in the cavity locates, under the state that the bonding layer 45 faces to the molten resin side, between the molten resin and the cavity side mold 22. And the molten resin filled in the cavity is solidified so as to be turned to a molded body. At the solidification of the molten resin, the bonding layer 45 of the transfer foil 40 in the cavity is bonded to the external surface of the molded body by the heat of fusion of the molten resin and the injection molding pressure.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a molding method and a method for simultaneous painting in which a transfer layer of a transfer foil is transferred simultaneously with the molding of a molten resin injected into a mold. This invention relates to a mold used and a transfer foil used in the method.

[Prior Art] Conventionally, methods have been known for attaching characters, patterns, etc. to the surface of a molded body formed by injection molding by silk printing, transfer, intaglio offset printing, or the like.

However, in the case of printing, if the printing area is large or the print has a complicated pattern, it is not easy to attach it to the molded object reliably, and in addition, multicolor printing requires many steps. It was difficult to align the position. Furthermore, in the case of transfer, if the object to be transferred has a cubic surface, the transfer operation is not easy and the transfer takes time.

In contrast to these methods, by placing a transfer foil in advance in an injection mold or compression mold and then injecting molten resin, the heat and pressure of the molten resin can be used to transfer the transfer foil at the same time as molding. There is a method of transferring characters, designs, etc. to a molded object.

[Problems to be Solved by the Invention] However, when using a method of transferring a design, etc. to a molded body at the same time as molding, the fixed side on which the injection path from the injection machine is formed is the cavity side of the molded body. This could not be done with a model.

In other words, since the designs etc. are mainly attached to the exterior side of the molded product, it is necessary to place the transfer foil on the cavity side. Therefore, the cavity side is not the fixed side where the injection path is formed, but the movable side (injection It had to be formed on the opposite side of the machine.

This requires that bosses, ribs, etc., which are often formed on the back side of the molded body, be located on the fixed side (ie, on the injection machine side).

Therefore, the mold has to be extremely complicated and large, and the ejector mechanism must be of the stripper plate type, or even if it is not, a plate must be provided on the core side to push out the eject bin. It disappears. When ejecting, the mold is opened by pulling the plate using a method such as a tension link, but at this time, it is necessary to open the parting part, which is the dividing surface between the cavity side and the core side, more than usual. Become. For this reason, the length of the tension link must be longer than the stroke required to remove the molded product, and in addition, since this tension link is contained within the mold, the stroke for opening the mold must be longer than the normal stroke. It must be larger than the mold,
There was a problem that the mold was thick and complicated.

In particular, this becomes even more complicated in the case of a mold for a molded article with an undercut. For many industrial parts, the more complex they are with undercuts, the greater the cost advantage of injection molding, but many of these require complicated ejection methods such as sliding, diagonal bins, and tipping bins. There is a need.

Therefore, it is necessary to regulate the timing when the mold is opened and closed, and in addition to increasing the number of plates, the mold must become thicker and larger.

This invention was made in view of the above problems, and
The purpose of this method is to transfer the transfer layer of the transfer foil using the heat and pressure of the molten resin without making the mold thick, large, or complicated. An object of the present invention is to provide a mold and a transfer foil used in the method.

[Means for Solving the Problems] In order to achieve the above object, the simultaneous painting and molding method according to the present invention is characterized in that a molten resin is placed between a mold consisting of a cavity side having an injection path for molten resin and a core side. After arranging the transfer foil having a transfer layer to be transferred to the mold and having holes penetrating between the front and back surfaces, with the transfer layer on the core side and the holes corresponding to the opening of the injection path, the transfer foil is placed in the mold. A cavity is formed between the cavity side and the core side by mold clamping, and the molten resin is injected from the injection machine into the cavity via the runner, and the injected molten resin passes through the hole in the runner from the cavity side. The molten resin is sent to the core side and located on the transfer layer side, and when the molten resin is solidified, a molded body with the transfer layer transferred to the external side is formed.

Furthermore, the mold used in the molding method of the simultaneous painting according to the present invention is a transfer foil having a transfer layer to be transferred to the molten resin and a hole penetrating between the front and back surfaces, and an injection mold for injecting the molten resin. It is characterized in that a cavity is formed by sandwiching the cavity side where a path is formed and where the opening of the injection path is located corresponding to the hole, and the core side which is located on the transfer layer side.

Further, in the simultaneous painting according to the present invention, the transfer foil used in the molding method is placed between a mold consisting of a cavity side and a core side having an injection path for molten resin, and is transferred to the injected molten resin. A transfer foil having a transfer layer, in which the holes through which the injected molten resin can pass between the front and back surfaces are aligned with the pitch of the transfer, and at the time of injection, the positions are arranged opposite to the opening of the injection path. It is characterized by being formed in

[Operation] The simultaneous painting according to the present invention is performed by a molding method, after placing a transfer foil having a transfer layer and having holes between the mold consisting of a cavity side having an injection path for molten resin and a core side. The molten resin injected into the cavity formed by the mold clamping is sent from the cavity side through the hole to the core side and located on the transfer layer side, and at the same time as the molten resin solidifies, the molded product appearance side The transfer layer is transferred to.

[Example 7] Hereinafter, an example of a mold used in the molding method for simultaneous painting according to the present invention will be described with reference to the drawings.

The mold 10 shown in Fig. 1 is composed of a so-called cavity side 20 which is the appearance of the molded product (see Fig. 4), and a so-called core side 30 which is the inside of the molded product with bosses and ribs. , the core side 30 is formed so as to be able to approach and separate from the cavity side 20.

The cavity side 20 is provided with a cavity side mounting plate 21 and a cavity side mold plate 22, and the core side 30 is provided with a core side mold plate 31 and a core side mold plate 31 facing the cavity side mold plate 22. A core-side mounting plate 33 is provided with an ejector plate 32 in between.

A recess 23 is formed in the cavity side template 22 on the surface facing the core side template 31.

The core-side mounting plate 33 is provided with a sleeve pin 34 that penetrates the ejector plate 32 and the core-side mold plate 31 and whose tip reaches the molded body. An ejector bin 35 is provided which reaches the parting surface of the compact. Further, a protrusion 36 corresponding to the recess 23 is formed on the surface of the core side template 31 facing the cavity side template 22 .

Then, by closing the mold 10 by bringing the core side mold plate 31 close to the cavity side mold plate 22, the cavity side 2
0 and the core side 30, a runner 13 is formed as a gap communicating with the cavity 11 via a cavity 11 and a gate 12.

As the gate 12, a side gate, a jump gate, a submarine gate, etc. are used. Especially in the case of Bingate,
A nameplate or label can be pasted on the gate of the molded body to hide it, and in the case of a film gate (flush gate), it can be made into a wide and thin film-like gate.

In addition, the cavity side mounting plate 21 and the cavity side template plate 2
A sprue bushing 24 is attached passing through the sprue bushing 2, and a sprue portion 25 passing through the sprue bushing 24 is formed in the sprue bushing 24. This sprue part 25
is an injection path that connects the runner 13 to the nozzle of an injection machine (not shown) that is brought into contact with the nozzle touch 24a.

Furthermore, on the cavity side 20, there is a parting line 1, which is a dividing line between the cavity side 20 and the core side 30 of the mold lO.
4, an optical sensor 15 for vertical direction detection and an optical sensor 16 for horizontal direction detection are provided. The vertical direction detection optical sensor 15 is disposed at both ends or one end of the metal 210 in the vertical direction, and the horizontal direction detection optical sensor 16 is disposed at both left or right ends or one end of the mold 10. The transfer foil 40 sent to is detected.

Then, the molten acrylonitrile styrene resin (AS resin) injected into the mold 10 under pressure is cured, thereby forming a molded body. Letters, designs, etc. are transferred onto the external side of the molded body using a transfer foil placed in advance on the parting line 14.

The transfer 91140 is, for example, 38μ, as shown in FIG.
m film-like polyethylene terephthalate (PET
), a release layer 42, a release layer 43, an ink layer 44 for patterns, letters, etc., and an adhesive layer 45 are stacked on top of each other in the order described. Then, by adhering the adhesive layer 45 to the molded body and peeling it off from the base 41 with the release layer 43, the ink layer 44, which is a transfer layer, is transferred, and patterns, characters, etc. are exposed on the outer surface of the molded body. This transfer foil 40 has a diameter of about 15 mm that penetrates between the front and back surfaces of the transfer foil 40 and is placed on the parting line 14 and opposite the opening of the sprue part 25 in accordance with the transfer pitch. A sprue hole 46 having a diameter is drilled (see FIG. 3).

Furthermore, it is more productive to form the transfer foil 40 into a shape that can be wound onto a roll or the like. Print eye marks at equal pitches about 20 cm apart. By detecting this with the vertical direction detection optical sensor 15 and the horizontal direction detection optical sensor 16 and controlling the position of the transfer foil 40, the sprue hole 46 of the transfer foil 40 pulled out from the roll etc. is placed in a predetermined position. The opening of the sprue portion 25 can be prevented from being blocked by the transfer foil 40. Instead of printing the eye mark, you can also make a hole.

Next, I will explain the molding method for simultaneous painting.

First, the mold 10 is opened with the core side 30 separated from the cavity side 20, and the transfer foil 40 with the base 41 side facing the cavity side 20 and the adhesive layer 45 facing the core side 3o is placed along the parting line. 14, and when the transferred part of the transfer foil 40 is located at the predetermined position, the transfer foil 40
(See Figure 3). The transfer foil 40 is sent out from one of the rolls (not shown) placed on both sides of the mold lO and is wound onto the other, but its positioning is as follows.
For example, the eye mark is detected by the vertical direction detection optical sensor 15 and the horizontal direction detection optical sensor 16.

When the transfer foil 40 is stopped, the core side 30 is brought closer to the cavity side 20 to close the mold 10, resulting in a mold clamping state. By closing the mold lO, a cavity II is formed, and at the same time, the transfer foil 40 is fixed on the parting line 14 with the transfer portion located in the cavity II.

At this time, since the cavity 11 of the transfer foil 40 is formed by the recess 23 of the cavity side template 22,
In close contact with the cavity side template 22 (core side template 31
), and the sprue hole 46
is arranged in communication with the opening of the sprue portion 25 facing the parting line 14.

Subsequently, resin is injected into the sprue portion 25 from a nozzle of an injection machine (not shown) that is brought into contact with the nozzle touch 24a. The heated and molten resin is transferred to the sprue section 25.
The cavity 11 is filled by being injected into the cavity 11 under pressure. The molten resin pushed out from the sprue part 25 to the runner 13 passes through the sprue hole 46 and is transferred? l! I4
The transfer foil 40 is sent to the adhesive layer 45 side of 0 (see arrow in FIG. 3), presses the transfer foil 40 against the cavity side template 22, and reaches the cavity 11 via the runner 13 and gate 12.

Therefore, the transfer foil 40 inside the cavity 11 has an adhesive layer 45
It is located between the molten resin and the cavity side mold 22 with the molten resin side facing the molten resin side.

The molten resin filled in the cavity 11 is then solidified to form a molded body A shown in FIG. 4.

When the molten resin solidifies, the transfer foil 4 inside the cavity 11
The adhesive layer 45 of No. 0 is adhered to the outer surface A of the molded body A by the melting heat of the molten resin and the injection molding pressure.

That is, the transfer is performed within the mold 10 at the same time as the molding.

Thereafter, after the molten resin is cooled, the mold 10 is opened, and the molded article A is ejected by the operation of the sleeve bin 35 as the ejector plate 32 moves, and the molded article A is taken out from the mold IO.

After taking out the molded body A, the transfer foil 40 is fed and a new transfer portion is placed in the cavity 11. At this time, since the sprue hole 46 is opened in accordance with the transfer pitch, it is reliably arranged in a state in which it communicates with the opening of the sprue portion 25 facing the parting line 14.

In this manner, the simultaneous painting according to this embodiment allows the transfer foil 40 to be positioned on the cavity side (that is, the injection machine side) 20 by the molding method. Therefore, since the ejector mechanism (slide core) can be provided on the core side 30 like the conventional non-transfer mold, it is only necessary to form the sprue part 25 on the cavity side 20 of the mold 10.
There is no need to make the mold lO thick, large, and complicated.

Incidentally, in the above embodiment, two molded bodies were formed using a two-plate molding die using a side gate (see Fig. 5), but the present invention is not limited to this, and for example, a three-plate molding mold using a bin gate may be used. There may be.

In this case, as shown in FIGS. 6 and 7, the gate 27 of the cavity-side template 26 is projected toward the core-side template 28, and the diameter of the gate hole 47 provided in the transfer foil 40 is For the diameter a, let e) b) *. Here, C is the diameter of the tip of the convex portion 29 formed on the cavity side mold plate 26. This is because if b is smaller than a, the molten resin will not flow to the adhesive layer 45 side of the transfer foil 40 and will enter the base 41 side of the transfer foil 40, causing the transfer foil 40 to flow to the side of the cavity that forms the outer surface of the molded body. This is because there will be some parts where is not placed. Therefore, b is 1.5 to 2 of a
It is preferable that it is twice as large. Furthermore, if b is larger than e,
There is also a risk that the molten resin will enter the base side 41 of the transfer foil 40.

Further, as shown in FIG. 7, the height gap C between the convex portion 29 of the cavity side mold plate 26 on which the gate 27 is formed and the top surface of the core side mold plate 37 is in a positive state (the convex portion 29 It is good as long as it enters the core side). However, if this is not the case (C is negative), then b is 1 of a.
．． 5 times or more, and the distance d between the cavity side template 26 and the core side template 37 (approximately equivalent to the amount of protrusion of the gate 27)
Need to be smaller. Because b is a's t, S
If it is less than twice as much, there is a risk that the molten resin will flow to the opposite side of the transfer foil 40, and if b is larger than d, there is a risk that the transfer foil 40 will break or the molten resin will flow to the opposite side of the transfer foil 40. be.

Note that the shape of the sprue hole 46 or the gate hole 47 is preferably a perfect circle or a modified oval or ellipse. At this time, if it is not circular, cuts or wrinkles will appear there. Of course, it doesn't matter if it's not circular as long as the corners are rounded.

[Effects of the Invention] The simultaneous painting molding method according to the present invention has a transfer layer that is transferred to the molten resin between the mold consisting of a cavity side having an injection path for the molten resin and a core side, and also has a transfer layer on the front and back surfaces. After arranging the transfer foil with holes penetrating between the cavity side and the core side, the transfer layer is positioned on the core side and the holes are arranged so as to correspond to the opening of the injection path, and then the mold is clamped to form a hole between the cavity side and the core side. A cavity is formed in the runner, and the molten resin is injected from the injection machine into the cavity via the runner.The injected molten resin is sent inside the runner from the cavity side through the hole to the core side, and is then transferred to the transfer layer side. It is characterized in that when the molten resin solidifies, a molded body with a transfer layer transferred to the external side is formed.

Furthermore, the mold used in the molding method of the simultaneous painting according to the present invention is a transfer foil having a transfer layer to be transferred to the molten resin and a hole penetrating between the front and back surfaces, and an injection mold for injecting the molten resin. It is characterized in that a cavity is formed by sandwiching the cavity side where a path is formed and where the opening of the injection path is located corresponding to the hole, and the core side which is located on the transfer layer side.

Further, in the simultaneous painting according to the present invention, the transfer foil used in the molding method is placed between a mold consisting of a cavity side and a core side having an injection path for molten resin, and is transferred to the injected molten resin. A transfer foil having a transfer layer, in which the holes through which the injected molten resin can pass between the front and back surfaces are aligned with the pitch of the transfer, and at the time of injection, the positions are arranged opposite to the opening of the injection path. It is characterized by being formed in

Therefore, the following effects are achieved.

■Molds for molding can be made at low cost.

■Since the size of the mold for molding can be made smaller and thinner, the molding equipment can also be made smaller, making it possible to reduce molding costs.6 ■It is possible to bring the cavity to the fixed side where the injection path is formed. Therefore, even molded bodies with complex undercuts can be molded.

■If you do this while avoiding sprues, the center of the cavity may become misaligned from the mold's sensor when the sprue is removed, and the injection pressure may cause the mold to become unbalanced and cause the mold to open, putting strain on the molding equipment and mold. , there is no such thing as unreasonableness. Furthermore, when the foil is passed in two lines, problems such as poor positional accuracy or complexity resulting in loss of versatility do not occur.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a mold used in the simultaneous painting and molding method according to the present invention. FIG. 2 is a sectional view showing a transfer layer portion of a transfer foil used in the simultaneous painting and forming method according to the present invention. FIG. 3 is a cross-sectional view showing the state in which the transfer foil is placed in the mold. Figure 4 shows the molded body, (a) is a plan view, (b)
is a sectional view, and (e) is a back view. FIG. 5 is an explanatory view showing two molded bodies. FIGS. 6 and 7 are enlarged sectional views of the gate portion showing other examples of the mold. 10-... Mold 11... Cavity 13... Runner 20... Cavity side 25... Sprue (injection path) 30... Core side 40... Transfer foil 44... Ink layer ( Transfer layer A...Molded body 2nd figure A1...Exterior side figure 4. Figure 9 Figure 9

Claims (2)

[Claims] (1) A transfer foil having a transfer layer to be transferred to the molten resin and having holes penetrating between the front and back surfaces is placed between a mold consisting of a cavity side having an injection path for the molten resin and a core side, After locating the transfer layer on the core side and arranging the holes so as to correspond to the openings of the injection path, a cavity is formed between the cavity side and the core side by clamping the mold. , the molten resin is injected from an injection machine into the cavity via a runner, and the injected molten resin is sent inside the runner from the cavity side to the core side through the hole and into the core side. A method for simultaneous painting and molding, characterized in that a molded article is formed which is located on the transfer layer side and has the transfer layer transferred to the external appearance side when the molten resin is solidified. (2) A transfer foil having a transfer layer to be transferred to the molten resin and having holes penetrating between the front and back surfaces is provided with an injection path through which the molten resin is injected, and a 2. The mold for use in the simultaneous painting and molding method according to claim 1, wherein a sandwiching cavity is formed by a cavity side where an opening of the injection path is located and a core side where the transfer layer side is located. (3) A transfer foil having a transfer layer placed between a mold consisting of a cavity side and a core side having an injection path for molten resin and transferred to the injected molten resin, the transfer foil having a transfer layer that is transferred to the injected molten resin; The holes through which the molten resin can pass between the front and back surfaces are aligned with the transfer pitch, and at the time of injection,
2. The transfer foil used in the simultaneous painting and molding method according to claim 1, wherein the transfer foil is formed at a position facing the opening of the injection path.