JPH08108451A - Multicolor molding method - Google Patents

Abstract

PURPOSE: To facilitate the multicolor molding of a plurality of products at once by a simple method by closing a second color part by a core slide pin freely slidable in the direction of a cavity mold to inject a first color and injecting a second color into the space formed by the core slide pin. CONSTITUTION: A first color is injected into the space formed by a cavity mold and a core mold from an injection unit through a runner and a submarine gate while a second color is injected through a separate runner 9B and a submarine gate 8B and a core slide pin 2 can be inserted in the second color forming part 1B of the cavity mold in a slidable manner. The core slide pin 2 closes the second color forming part 1B and the first color is injected through the runner and the submarine gate to form a first color part 1A. Next, the second color is injected into the space formed by the movement of the core slide pin 2 in the direction shown by an arrow D through the runner 9B and the submarine gate 8B to form a second color part 1B and, after mold opening, a molded product is taken out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor molding method for plastics.

[0002]

2. Description of the Related Art A molded product L, for example, A shown in FIGS.
A button for a V device is formed by adjoining a first color portion 1A of a main body and a second color portion 1B. For such a molded product, a conventional two-color molding machine is used and shown in FIG. Thus, the first color portion 1A was first molded, and then the core mold 26 side was rotated to mold the second color portion 1B.

[0003]

As described above, the molding by the two-color molding machine requires the molds for the primary molding and the secondary molding even for a simple molded product, and the mold for the rotation of the core mold is required. It takes time. It is also difficult to take a plurality of molds with one set of dies.

An object of the present invention is to provide a multi-color molding method which can mold a plurality of moldings at once by a simple method which does not require mold rotation for a simple molded article.

[0005]

According to the present invention, in plastic injection molding, a core slide pin is provided on the core mold side so as to be slidable in the direction of the mold, and the second color portion is closed by the core slide pin. The first color is injection molded, then the core slide pin is moved, and the second color is injection molded into the created space.

[0006]

According to the present invention, the first color is injection-molded by closing the second color portion with the core slide pin, and then the second color is injection-molded in the space formed by moving the core slide pin.

In this way, multicolor molding can be performed with one set of molds without rotating the core mold side.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a mold for molding the molded product L shown in FIGS. 7 and 8 according to the present invention. In FIG. 1 and FIG. 2, a cabinet type 7 and a core type 6
The first color is emitted from the injection unit (not shown) through the runner 9A and the submarine gate 8A, and the second color is emitted through the runner 9B and the submarine gate 8B into the space formed by and. The core slide pin 2 can be slidably inserted into the second color molded portion 1B.

Next, the mode of molding will be described. FIG. 1 shows the state of primary molding, in which the core slide pin 2 moves in the direction of arrow U and closes the second color molded portion 1B, and the first color is injected through the runner 9A and the submarine gate 8A. Then, the first color portion 1A is molded. Next, as shown in FIG. 2, the second color is injected through the runner 9B and the submarine gate 8B into the space formed by the core slide pin 2 moving in the direction of arrow D, and the second color portion 1B is molded. . Then, the mold is opened and the molded product is taken out.

FIG. 3 shows an embodiment in which a plurality of the above-mentioned molded products L are simultaneously molded. Figure 3 shows this multiple (8 in this example).
The main part of the mold for individual picking is shown. Note that, in this figure, portions corresponding to those in FIG.

The main part of this mold is arranged in such a manner that the core base 3, the cabinet base 4 and the fixing plate 5 are superposed.
The cabinet base 4 and the core base 3 are moved relative to the fixed plate 5 in the axial direction (direction of arrow X), and the mold is clamped and the mold is opened. A core mold 6 is arranged on the core base 3, and a mold mold 7 is arranged on the cabinet base 4 so as to face the core mold 6. Further, adjacent to each core die 6 of the core base 3, core slide pins 2 are provided corresponding to the molding parts of the second color.

A first color ejection port A is provided at the center of the fixed plate 5, and the spools 10C and 10A communicate with the runner 9C on the starting surface of the core base 3 through the fixed plate 5 and the cabinet base 4. ing. The runner 9C is divided into runners 9A for each mold, and is injected into the respective molds 6 through the submarine gate 8A of the mold base 4. On the other hand, the fixed plate 5 is provided with a second-color ejection port B on the outer side in the circumferential direction of the contact surface with the cabinet base 4, which is divided into respective molds by the runners RC, RB, and RA. Through the spool 10B provided in the core base 3 and communicates with the runner 9B of the core base 3. And runner 9B to submarine gate 8 of cabinet base 4
It is designed to be injected into the mold 6 through B.

In the molding, first, the core slide pin 2 is moved to the mold side to close the second color portion of the mold 6, and the first color is injected from the injection port A from 10C → 10A → 9C → 9A → 8A.
It is injection-molded into a mold 6 through. Next, the core slide pin 2 retracts, and the second color goes from the injection port B to RC → RB.
->RA->10B->9B-> 8B is passed through and injection-molded into the cavity mold 6.

4 and 5 show another embodiment of the present invention. The present embodiment is an example of molding a molded product K shown in FIG. 6, that is, one in which the central portion of the button is a second color figure. As shown in the figure, the second color portion 11B at the center is ejected from the pin gate 18B, and when the slide core pin 12 is raised in the U direction, the pin gate 18B is closed.

FIG. 4 shows the primary molding, in which the slide core pin 12 is raised in the U direction and the submarine gate 1
The first color portion 11A is injection molded from 8A. Next in FIG.
As shown in FIG. 5, the slide core pin 12 is bent in the D direction, and the second color portion 11B is injection-molded by the pin gate 18B in the space with the mold. Also in this embodiment, as in FIG. 3, a plurality of molds can be arranged and molded at once.

[0017]

As described above, the present invention has the following effects. (1) There is no need for separate molds for primary molding and secondary molding,
In addition, multicolor molding can be performed without rotating the core mold side, and the manufacturing cost can be reduced. (2) A plurality of moldings can be easily performed at once with one set of molds. (3) The present invention can be applied not only to different colors but also to molding of different materials.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the secondary molding of FIG.

FIG. 3 is a perspective view showing a mold of an embodiment of the present invention for simultaneously molding a plurality of pieces.

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

5 is a cross-sectional view showing the secondary molding of FIG.

FIG. 6 is a perspective view showing a button to be implemented in FIG.

FIG. 7 is a perspective view showing a button on which the present invention is implemented.

FIG. 8 is a sectional view of FIG.

FIG. 9 is a sectional view showing a conventional molding method.

[Explanation of symbols]

 1A, 11A ... 1st color part 1B, 11B ... 2nd color part 2, 12 ... Core slide pin 3 ... Core base 4 ... Cabinet base 5 ... Fixing plate 6, 26・ ・ ・ Core type 7 ・ ・ ・ Cavity type 8A, 8B, 18A ・ ・ ・ Submarine gate 18B ・ ・ ・ Pin gate 9A, 9B, 9C, 19A ・ ・ ・ Runners 10A, 10B, 10C ・ ・ ・ Spool RA, RB, RC: Runner A, B: Ejection port

Claims (1)

[Claims] 1. In plastic injection molding, a core slide pin is provided on the core mold side so as to be slidable in the direction of the mold, the second color portion is closed by the core slide pin, and the first color is injection molded. Move the core slide pin,
A multicolor molding method, characterized in that the second color is injection-molded in the completed space.