JPS6189818A - Multi-color resin molding methods and multi-color molding tool used therefor - Google Patents

Abstract

PURPOSE:To manufacture multi-color resin molded body with high integrity by a method wherein a first resin molding is formed by abutting a working mold against a first commutable mold and, after that, a second resin molding is formed integrally with the first resin molding by abutting some portion of the working mold, which is the molding surface of the working mold and is separated from the first commutable mold, against a second commutable mold. CONSTITUTION:Firstly, a first resin molding M is formed by injecting first resin through a gate 201 in a cavity a1, which is made by abutting a working mold 1 against a first commutable mold 2. Secondly, the working mold 1 is separated from the first commutable mold 2 and, after that, clamped together with a second commutable mold 3 in order to make a cavity a2 between both the molds 1 and 3. Finally, a second resin molding N is formed by injecting second resin through the space of a through hole 11c. Consequently, the second resin fills the second cavity a2 and at the same time flows around to spaces S1 and S2 in the rear of the first resin molding M so as to mechanically hold the first resin molding M. Thus, no trouble such as the separation of both the resin moldings from each other occurs, resulting in enabling to realize the multi-color resin molding by resins, the affinity between both of which is small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a multicolor resin molding method and an improvement of a multicolor resin mold used therein.

The present invention can be utilized in various industrial fields, such as the plus deck molding industry, which requires multicolored resin molded products molded with different resins.

[Prior art 1] One regular type that is always used and two first and second exchangeable types that are used interchangeably. A multicolor resin molded article is known.This conventional multicolor resin molding method is
A regular mold and a first exchange mold are brought into contact with each other, and a first resin is injected into the first cavity to form a first resin molded body. With this first resin molded body fixed to the regular mold, the first
The replaceable mold is replaced with a second replaceable mold, a second resin is injected into the second cavity between the regular mold and the second exchange mold to form a second resin molded body, and a second resin molded body is formed. and a second resin molded body.

[Problems to be Solved by the Invention] In the method for producing a multicolored resin molded body, the second resin molded body is different from the first resin molded body.
It contacts the resin molded body in a molten state within the second cavity, solidifies there, and forms the second resin molded body integrally with the first resin molded body, thereby obtaining a multicolored resin molded body. When the affinity of both the resins constituting the first resin molded body and the second resin molded body is high, the bond between the image molded bodies is strong and a multicolored resin molded body with high integrity can be obtained. However, when one resin is polyethylene and the other resin is vinyl chloride resin, the affinity between the resins is low, so the multicolored resin molded product obtained by the conventional method described above is The bonding force between the molded body and the second resin molded body is weak, causing a problem of separation during use.

An object of the present invention is to provide a multicolor resin molding method and a multicolor resin molding die that produce a multicolor resin molded article with high integrity even between resins with low affinity.

[Means for Solving the Problems] The multicolor resin molding method of the present invention includes a main body constituting a main part, a main body fixed to the main body at least at a first position and a second position of the main body. A regular mold consisting of a movable body that forms a part of the mold surface, and at least two first exchangeable molds and a second exchangeable mold that come into contact with the regular mold to form different first and second cavities, respectively. A first step of abutting the regular mold and the first replaceable mold with the movable body of the regular mold fixed at the first position of the main body using a multicolored resin mold consisting of; a second step of filling a first resin into a first cavity formed by the regular mold and the first replaceable mold to form a first resin molded body; separating the first replaceable mold from the regular mold; , Next, the movable body of the regular mold is moved to the second position of the main body, and a part of the mold surface of the regular mold that has formed the first resin molded body is separated from the first resin molded body. a third step of bringing the second exchangeable mold into contact with the regular use mold; a second cavity formed by the regular use mold and the second exchangeable mold is filled with a second resin; The second resin molded body is integrated with the first resin molded body.
A fifth step of forming a resin molded body to form a multicolored resin molded body; and a sixth step of separating the second exchange mold from the conventional mold and taking out the obtained multicolored resin molded body are carried out in sequence. It is characterized by this.

Further, the multicolor resin molding mold of the present invention includes a regular mold constituting one of the split molds, and at least two first interchangeable molds that come into contact with the regular mold to form different first and second cavities, respectively.
A multicolor resin molding mold consisting of a second exchangeable mold, the regular mold has a main body forming its main part, and when the regular mold is in contact with the first replaceable mold, the first mold of the main body -C is fixed at the second position of the main body when it is in contact with the second exchangeable mold, and is fixed at the second position of the main body when it is in contact with the first and second exchangeable molds. It is also characterized in that it is comprised of a movable body that forms part of the mold surface.

In the multicolor resin molding method and multicolor resin mold of the present invention, after the first resin molded body is molded, the main body and the movable body that constitute the regular mold move relatively, and the molded first resin A part of the surface of the molded body and a part of the mold surface of the conventional mold are separated, and a space, that is, a space serving as an undercut part is formed at the rear of the first mold. For this reason, when the second resin molded body is molded, the second resin molded body partially wraps around the back of the first resin molded body, forming a so-called undercut portion. Therefore, the first resin molded body is mechanically held and fixed by the second resin molded body.

As a result, even if the affinity between the resins of the first resin molded body and the second resin molded body is low and the bonding strength is weak, the second resin molded body mechanically fixes the first resin molded body. In addition, it is possible to obtain a multicolored resin molded article that has high integrity and does not separate even when resins have low affinity.

[Detailed Description of the Structure of the Invention] The multicolor resin molding mold of the present invention is composed of a regular mold and at least two first and second exchange molds.

This commonly used type has its own characteristics.

The regular type consists of a main body and a movable body. The movable body is fixedly held with respect to the main body at least at a first position and a second position of the main body.

The first position is a position where the movable body is fixed when engaging with the first replaceable mold, and the second position is a position where the movable body is fixed when engaging with the second replaceable mold. One end surface of the movable body constitutes at least a part of the mold surface forming the cavity at each fixed holding position.

The relative relationship between the first position and the second position of the movable body is such that the movable body protrudes toward the cavity side with respect to the main body or conversely retreats. When the movable body protrudes, the first resin molded body formed between the movable body and the first replaceable mold is protruded from the main body while being held by the movable body. Conversely, when the movable body retreats, the first resin molded body formed by the first exchangeable mold is held by the main body, and the movable body retreats in the direction of separation from the first resin molded body.

A space is formed behind the first resin molded body by this relative movement between the main body and the movable body (this space forms part of the second cavity when the second exchangeable mold is in contact with the regular mold). do).

Specifically, the movable body is configured as a core pin, a core block, or the like. Note that a part of the end surface of the movable body may come into contact with the mold surfaces of the first exchangeable mold and the second exchangeable mold.

Relative movement between the main body and the movable body can be performed using a biasing force of a coil spring, a hydraulic cylinder device, or the like. Further, the main body and the movable body can be fixed by using a wedge-shaped gap member, a lock pin, or other locking mechanism.

The first step of the multicolor resin molding method is a step of bringing the regular mold and the first exchange mold into contact with each other with the movable body fixed at the first position to form a first cavity.

Note that the first exchangeable mold and the second exchangeable mold have mold surfaces for forming predetermined first and second resin molded bodies, respectively, and both the first and second exchangeable molds are substantially the same as conventional ones. There is no special difference from the exchange type of .

The second step consists of a first mold made of a regular mold and a first exchange mold.
This is a step of filling the cavity with a first resin to form a first resin molded body.

As the resin, thermoplastic resin is generally used, but thermosetting resin, rubber, etc. may also be used. Further, although the resin is generally filled into the first cavity by injection molding, it may be filled by other methods.

The third step is! '11 This is a process of separating the exchangeable type from the regular type and then moving the movable body of the regular type to the second position of the main body.

When separating the first replacement mold from the regular mold, the molded first resin molded body is held in the regular mold. When moving the next movable body to the second position relative to the main body, the first
The resin molded body is separated from either the main body or the movable body and held in use. Then, a part of the surface of the first resin molded body formed by the mold surface of the conventional mold is separated from a part of the mold surface of the conventional mold.

The fourth step is a step of bringing the second replaceable mold into contact with the regular mold to form a second cavity.

The fifth step is to fill the cavity formed by the regular mold and the second exchange mold with a second resin, form a second resin molded body integrally with the first resin molded body, and form a multicolor resin molded body. This is the process of forming.

This second resin molded body fills the remaining second cavity space occupied by the first aluminum molded body.

That is, the space between the first resin molded body and the regular mold formed by the relative movement between the movable body of the regular mold and the main body (the space behind the first resin molded body) also contains the resin of the second resin molded body. is filled. For this reason, the second resin molded body is configured to mechanically hold the first resin molded body.

The sixth step is a step in which the second exchange mold is separated into regular molds and 1q of multicolored resin molded bodies are taken out. As a result, a multicolored resin molded body is obtained.

I Effects of the Invention] In the multicolor resin molding method J3 of the present invention and the multicolor resin mold of the present invention, the molded body 49 is formed in a form in which the second resin molded body partially encloses the first resin molded body. . For this reason, even if the resins that make up the first resin molded body and the second resin molded body have little affinity, the first resin molded body and the second resin molded body are mechanically bonded, and the two are separated. No other inconveniences will occur. Therefore, it becomes possible to mold multicolored resins such as polyethylene and vinyl chloride resin, which have little affinity with each other, which was previously impossible.

[Example] Next, the present invention will be explained in detail.

In the examples, a multicolor resin mold whose main part is shown in cross section in FIGS. 1 and 2 was used. This type is commonly used type 1 and
The main components are an exchange type 2 and a second exchange type 3. Note that the first replaceable mold 2 and the second replaceable mold 3 are basically not significantly different from the replaceable molds of conventional multicolor resin molding molds, so only the main parts are shown.

The regular type 1 includes a main body 11, a first core bin 12, a core block 13, a middle plate 14, a push-up plate 15, a mounting plate 16, a hydraulic cylinder 17, a return pin 18, a first push-up pin 19,
Second core bin 20, second push-up bin 21, spacer member 2
It is made up of 2nd grade.

Note that the intermediate plate 14, the first core bin 12, the core block 13, and the hydraulic cylinder 17 are fixed to the mounting plate 16 here.

The main body 11 has a trapezoidal mold surface, and a through hole 11 a is formed in the center of the main body 11 . The surface is on the same plane. A through hole 110 is also formed in the runner portion 11b of the main body, into which the second push-up bottle 21 is inserted. The first push-up pin 19 is for pushing out the molded multicolored resin molding, and the second push-up pin is for pushing out a part of the runner. Both push-up pins 19.
21 and the return pin 18 are attached to the presser plate 15.
It is fixed at 1.

Furthermore, the main body 11 has a circulation hole 11d111e for the core pin.
is formed. A first core pin 12 is provided in the through hole 11d.
However, the second core bin 20 is inserted into the through hole 11e. The first core pin 12 is fixed to the intermediate plate 14 by a pressing plate 141. Further, the second core bin 20 is configured as a piston of the hydraulic cylinder 17. The core block 13 is held slidably in the axial direction in a hole 11f that opens on the mold surface side of the main body 11, and is held in the center by a plurality of engagement pins 131.

It is connected to the plate 14. A biasing spring 132 in a compressed state is incorporated around each engaging pin 131, and biases the intermediate plate 14 and the main body 11 in a direction that moves them away from each other.

The spacer member 22 is held on the middle plate 14 of the regular mold 1. This spacer member 22 is composed of a bracket 221 fixed to the middle plate 14 with bolts, a hydraulic cylinder 222 and a piston 223 fixed to this bracket 221, and an oval-shaped sube+1224. As shown in FIG. 2, this spacer member 22 is inserted laterally when a gap is formed between the middle plate 14 and the main body 11, and the spacer 224 is inserted laterally to fill the gap between the middle plate 14 and the main body 11. It is to be ensured.

One end of the return bin 18 is fixed to the push-up plate 15, and the other end is inserted into the through hole 119 of the main body 11.

The head end of the return bottle 18 is locked to the shoulder of the through hole 110, and movement of the push-up plate 15 and the push-up bottle 19.21 to the left in FIG. 2 is prevented. This return bin 18
A biasing spring 181 is installed in a compressed state around the holder, and biases the main body 11 and the push-up plate 15 away from each other.

The multicolor resin mold of this example has the above-described configuration.

Next, a molding method using this mold will be explained.

First, the regular mold 1 is moved to a position opposite to the first replaceable mold 2, and the regular mold 1 is pressed against the first replaceable mold 2.

FIG. 1 shows a state in which the regular mold 1 and the first replaceable mold 2 are in contact with each other. Here, since the urging force of the urging spring 131 that urges the main body 11 and the middle plate 14 in a direction away from each other is much smaller than the pressing force of the hydraulic cylinder 17, there is a gap between the middle plate 14 and the main body 11. is kept at O. Regular type 1 and 1st
A first resin is injected from a gate 201 formed in the first exchangeable die 2 into a cavity a1 formed by the abutment of the exchangeable die 2, and a first resin molded body M is molded.

Thereafter, the first replaceable mold 2 and the regular mold 1 are separated, and the regular mold 1 is clamped with the second replaceable mold 3 shown in FIG.

Specifically, the regular mold 1 is driven to the left in FIG. 1 relative to the first exchange mold 2, and then driven in a direction substantially perpendicular to this driving direction and pressed against the second exchange mold 3. At this time, when the pressing force of the hydraulic cylinder 17 disappears, a gap is formed between the main body 11 of the regular type and the intermediate plate 14 due to the urging force of the urging spring 131. As a result, the first main body 11 of the regular type 1
The core bin 12 and the core block 13 are moved relative to each other, and the first
The core bin 12 and the core block 13 are moved back by the gap S with respect to the main body 11. As a result, a columnar space S1 and a space S2 surrounding the outer periphery of the first molded body M are formed between the first resin molded body M8 and the respective tip surfaces of the first core bin 12 and core block 13. At the same time, the second core bin 20
is driven to the left in FIG. 1, and the gate 3b for second resin molding is opened.

Next, the piston 223 of the spacer member 22 protrudes, and the spacer 224 is driven upward in FIG. 2 to be wedge-shaped between the main body 11 and the middle plate 14, and the spaces 5181 and S2 are held. In this state, hydraulic pressure is applied to the hydraulic cylinder 17 again, and the main body 11 of the regular mold 1 is pressed against the second exchange mold 3 via the intermediate plate 14 and the spacer 224 by the hydraulic cylinder 17. As a result, the regular mold 1 and the second exchangeable mold 3 are clamped.

A second cavity a2 is then formed between the two.

Next, the through hole 11 created by drawing in the runner 3a, gate 3b, and second core bin 20 of the second exchangeable mold 3
The second resin is injected through the space c, and the second resin molded body N is molded. As a result, the second resin fills the second cavity a2 and the space S1 behind the first resin molded body M.
, S2 to mechanically hold the first resin molded body M.

Thereafter, the second replacement mold 3 and the regular mold 1 are separated 111, and the spacer 224 of the spacer member 22 is retreated.

The obtained multicolored resin molded body is separated from the regular mold 1 by pushing up the push-up plate 16 to protrude the return bin 18, and is removed from the mold surface of the regular mold 1, thereby obtaining a multicolored resin molded body. .

In this example, ABS was used as the first resin and vinyl chloride resin was used as the second resin. Although almost no adhesiveness was observed between the first resin molded body M and the second resin molded body N formed of the respective resins, the second resin molded body wrapped around behind the first resin molded body M The first resin molded body M and the second resin molded body N were integrally fixed by the body N, and there was no fear of separation.

[Brief explanation of drawings]

1 and 2 are sectional views of the main parts showing a part of the mold and the molding state of this example, and FIG. 1 is a main part showing the state where the regular mold and the first exchange mold are in contact with each other. A sectional view and FIG. 2 are principal part sectional views showing a state in which the regular type and the second replacement type are in contact with each other. 1... Regular use type 2... First replacement type 3...
・Second exchange type 11...Main body 12...First core bin 13...Core block 14...Middle plate
15... Push-up plate 16 mounting plate 1
7... Hydraulic cylinder 22... Spacer member M
...First formed body N...Second formed body S, 81.82...Space patent applicant Toyoda Gosei Co., Ltd. agent Patent attorney Hirodo Okawa Patent attorney Shudo Fujitani Patent attorney Akio Maruyama Figure 1

Claims (4)

[Claims] (1) A regular mold consisting of a main body constituting the main part, the main body, and a movable body that is fixedly held to the main body at least at a first position and a second position of the main body and forms a part of the mold surface; Using a multicolored resin mold consisting of at least two first exchangeable molds and a second exchangeable mold that contact the mold and form different first and second cavities, first, the movable mold of the regular mold is used. a first step of abutting the regular mold and the first replaceable mold while the body is fixed at the first position of the main body; a second step of filling a first resin with a first resin to form a first resin molded body, separating the first replacement mold from the regular mold, and then moving the movable body of the regular mold to the second position of the main body; a third step of separating a part of the mold surface of the regular mold that has formed the first resin molded body from the first resin molded body; a third step of bringing the second exchangeable mold into contact with the regular mold; Step 4: Filling a second resin into a second cavity formed by at least a mold surface separated from the first molded body of the regular mold and a mold surface of the second exchange mold, and molding the first resin. a fifth step of forming a second resin molded body integrally with the body to form a multicolored resin molded body; a fifth step of separating the second exchangeable mold from the conventional mold and taking out the obtained multicolored resin molded body; A multicolor resin molding method characterized by sequentially performing six steps. (2) Consists of a regular mold that constitutes one of the split molds, and at least two first exchangeable molds and a second exchangeable mold that come into contact with the regular mold to form different first and second cavities, respectively. In the multicolor resin mold, the regular mold has a main body constituting its main part, and when the regular mold is in contact with the first exchangeable mold, it is fixed at a first position of the main body, and the second exchangeable mold is fixed at a first position of the main body. a movable body that is fixed at a second position of the main body when in contact with the mold, and at least a portion of the second
A multicolor resin molding die characterized in that the cavity is formed closer to the regular mold than the first resin molded body filled and molded into the first cavity. (3) The multicolor resin mold according to claim 2, wherein the second position of the movable body is located at a position farther back from the first position with respect to the main body. (4) The second position of the movable body is located at a position further forward relative to the main body from the first position, and is formed between the regular mold and the first exchangeable mold, and the first resin molded body is held by the movable body. A multicolor resin mold according to claim 2.