KR20120005226A - Dual injection molding method and mold structure - Google Patents

Abstract

PURPOSE: A double injection molding method of synthetic resin articles is provided to perform a double injection molding of a various synthetic resin products by successively performing first and second modeling first and second molds. CONSTITUTION: A double injection molding structure of synthetic resin articles comprises first and second molds. Each molds comprises a fixed die plate(100), movable die plates(200), eject plates(300), and cores(30). Each fixed die plates comprise lower molds(10). The first injection-molded article is settled on the lower mold of the fixed die plate of the second mold. Upper molds(20) of each movable die plates open and close the lower die by an elevating operation. The eject plates are supported by support plate(400) and elevated. The cores are shaft-combined on the upper side of the eject plate. The cores are penetrated in the cavity(40) of the lower mold and fixed die plate and obliquely installed perpendicular.

Description

Dual injection molding method and mold structure for molding the resin

The present invention relates to a double injection molding method of a synthetic resin and to a mold structure for forming the same to enable the double injection molding using two different types of synthetic resin material, more specifically, the hinge and the hook, such as the lid of the container Double injection molding method for synthetic resin products having protrusions such as to enable molding of thick resin products more efficiently and to produce products with high quality or various designs. It relates to a mold structure for the molding.

In general, double injection molding is injection molding of two different synthetic resin materials in a single product, that is, injection molding is completed in a primary mold using a synthetic resin material, and then the primary molded product is used as a secondary mold. Secondly, by injection molding, products having a double thickness as different synthetic resin materials are molded.

For example, in the case of injection molding a synthetic resin product having a standard thickness or more, the injection molding time is very expensive due to the inherent properties of the synthetic resin material, as well as an uneconomical problem that the injection molding time becomes considerably longer due to its thickness. Due to the difficult characteristics, a double injection molding method in which injection molding is divided into two is performed.

This double injection molding method has already been proposed and widely used in the related art, and as a result of injection molding in a form of overlapping different synthetic resin materials, it is possible to easily produce a relatively thick product and at the same time transparent to different materials, that is, external surfaces. It can be molded into a product having a double structure, such as injection molding a double material, and has the feature of making the product more advanced.

Therefore, it is widely applied in various fields such as various electronic products, household goods, and even applied to very small size synthetic resin products such as cosmetic containers.

However, such a conventional double injection molding method has a very useful property in the case of injection molding a relatively simple product, but if there is a protruding part due to the structural characteristics of the product, there is a problem that double injection molding is very difficult due to its protruding part. .

As shown in FIGS. 1 and 2 of the accompanying drawings, as shown in the lid A to open and close the container B, the protrusion protrudes in a direction perpendicular to a side of the lid A, such as a hinge or a hook. In the case of having the piece A1, the protruding piece A1 is easily deformed due to the heat generated during the molding of the secondary molding after the primary molding is completed.

In other words, in the case of a product having a protrusion (A1) such as a hook or a hinge integrally on one side of the lid (A), after injection molding in the primary mold, the molded product is seated on the secondary mold and secondary injection molding However, in the case of this secondary molding, there was a structural problem that the protruding piece A1 protruding from the body was deformed due to the high heat in the cavity of the secondary mold.

Therefore, when injection molding a product having a protruding part on the body of the molded article as described above, after molding the inner and outer bodies separately, by adopting a method of manufacturing them integrally by adhering them with an adhesive or specifying the inner and outer bodies Injection molding with a separate bonding structure that can be coupled to each other in the part is manufactured as a structure to combine them integrally.

However, the product manufactured by the conventional method has a difficult and cumbersome problem of adhesive molding of the inner and outer bodies, and the product is advanced due to the minute spacing or the assembled parts between the assembled inner and outer bodies. There was an unproblematic problem.

The present invention has been made in view of the above-mentioned various conventional problems, and its object is to allow injection molding of a relatively thick synthetic resin material or a different type of synthetic resin into a double structure, but also to a body such as a hinge or a hook. The present invention also provides a double injection molding method of a synthetic resin that enables a double injection molding of a product having a protruding piece protruding at a predetermined interval.

Another object of the present invention is to improve the structure of the mold according to the double injection molding injection molding the primary molded primary molded article to the secondary molded article to form a mold structure of a synthetic resin to enable a double injection molding of various types of molded products In providing.

In order to achieve the above object, the present invention sequentially forms a series of molding processes in which a primary injection molded product is molded by using a primary mold, and then the secondary injection molded product is seated on a secondary mold and subsequently molded. This is possible.

In the present invention, two or more different synthetic resins are not simply integrally injected to overlap the double, but also a unique product having a protruding piece protruding from the injection molding can be double injection molding.

This double injection mold method injects molten resin into the cavity formed between the lower mold of the fixed die plate and the upper mold of the movable die plate in the primary mold to perform the first injection molding, and then the secondary mold through the second mold. Injection molding.

In the secondary mold, the upper and lower molds are separated, and the core is raised to the upper portion of the lower mold according to the conditions of the primary injection molded product so that the primary injection molded product can be seated at the correct position. After the primary injection molded product is seated on the raised core at the top, the core in which the primary injection molded product is seated is lowered to its original position, and the primary injection molded product is tightly seated inside the cavity of the lower mold without any gap.

Subsequently, the upper and lower molds are combined with each other to inject a secondary molten resin into the cavity therebetween so as to inject the secondary injection molded article, so that double injection molding is possible.

The present invention has the effect of injection molding a variety of synthetic resin products by performing primary molding and secondary molding sequentially using primary and secondary molds having a relatively simple structure.

In particular, the present invention has the effect that the protruding pieces of various related parts such as hinges, hooks, etc. are integrally formed on one side of the injection molded product, or even products having a unique structure can be molded by the method of double injection molding.

1 is an embodiment of a product molded by the present invention
Figure 2 is an enlarged configuration of the lid in Figure 1
3 is a block diagram of the present invention primary mold
4 is a separated configuration of FIG.
5 is a plan view showing the lower mold of FIG.
Figure 6 is a plan view of the first injection molded primary injection molded article of the present invention
7 is a front cross-sectional view of FIG.
8 is a configuration diagram of the secondary mold of the present invention
9 is a separated configuration of FIG.
10 is a cross-sectional view of a molded article molded by the present invention secondary injection molding
11 to 15 is an operation explanatory view molded by the secondary mold of the present invention
Figure 16 is a block diagram showing a manufacturing process of the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Detailed description for carrying out the present invention will be described below with reference to the accompanying drawings.

The present invention is divided into primary injection molding and secondary injection molding, and the primary injection molding is molded by the primary mold, and the secondary injection molding is sequentially formed by the secondary mold to form a double injection molded article. Done.

First, the primary mold is as shown in Figures 3 to 5 of the accompanying drawings.

It is composed of a movable die plate 200 having a fixed die plate 100, the lower die 10 is installed, and an upper die 20 that is opened and closed by a lifting operation at an upper portion thereof. Eject plate 300 which is supported by the support plate 400 to move up and down is installed, and at the same time, the eject plate 300 is installed to the core 30 vertically inclined slightly.

In the lower mold 10 installed on the fixed die plate 100, a cavity 40 for injection molding the primary molded article when combined with the upper mold 20 is formed in a pair of left and right, and each lower mold Inside the 10, slide cores 30 are provided at both sides.

The core 30 is composed of two sets are installed to be inclined mutually, they are installed to be inclined vertically to penetrate the fixed die plate 100 and the lower mold 10 is moved up and down by the eject plate 300 As a result of this, the upper and lower ends of the lifting operation are provided to each other.

In other words, the core 30 is formed in a rod shape, but the two are inclined to each other to provide a function of forming the protruding piece A1 of the product to be injection molded, and take out the molded product which is completed by lifting operation. It will also have a function.

In addition, the upper die 20 is installed on the movable die plate 200 installed at the upper portion of the fixed die plate 100 to open and close the cavity 40, and the movable side attachment plate 500 is installed at the upper portion thereof. The sprue bush 21 for supplying the molten resin into the cavity 40 through the upper mold 20 is provided at these centers.

At this time, the cavity 40 is to have a shape corresponding to the primary injection molded product in the process of molding into a double injection molded product.

As described above, the primary injection molded article 1 injection molded in the primary mold has one primary injection molded article 1 formed by two runners and a gate as shown in FIGS. 6 and 7 of the accompanying drawings. It has a form that is connected to the molded article.

8 and 9 of the accompanying drawings show the structure of the secondary mold according to the present invention.

That is, the secondary mold of the present invention is for double injection molding different materials on the outer surface of the primary injection molded product 1 that is injection molded in the primary mold, and the secondary injection molding according to the secondary mold is Will be done.

The secondary mold has a structure similar to that of the primary mold, but is configured by changing the structure of the cavity of the upper mold in the upper and lower molds.

Its structure is the lower die (10a) is installed on the fixed die plate (100a), the lower portion of the fixed die plate is installed while the support plate (400a) is supported on the support plate 400a, the lifting operation is possible, on the upper surface Lower ends of the rod-shaped cores 30a are axially coupled to be inclined to penetrate into the lower mold 10a.

In addition, the upper portion of the fixed die plate (100a) is installed so that the movable die plate (200a) is moved up and down by the movable side mounting plate (500a), the lower mold 20a is installed at the lower portion, sprue at the center The bush 21a is installed to supply molten resin.

In addition, the cavity 41 for forming the secondary injection-molded product 2 is formed between the upper and lower molds 10a and 20a.

Therefore, the structures of the primary and secondary molds of the present invention configured as described above are sequentially formed by a manufacturing process according to the following injection molding method, and synthetic resins of different materials are doubled by going through the molding process. It is possible to obtain a double injection molded article that is injection molded.

1st process (1st injection molding process)

In the present invention, in the first mold, the first injection molded article 1 is injection molded, and the first injection molded article 1 of synthetic resin material is injection molded using the first mold.

In the primary mold, the lower mold 10 of the fixed die plate 100 and the upper mold 20 of the movable die plate 200 are coupled to each other to form a cavity 40 formed between the upper and lower molds 10 and 20. Molten resin is injected into the inside of the) to complete the first injection molding.

When the primary molding is completed, the movable die plate 200 is raised to separate the upper and lower molds 10 and 20 so that the primary injection-molded product 1 is taken out.

The first injection molded article 1 is produced in a pair of left and right, and when the molding is completed, the shape is maintained as shown in the accompanying drawings by the runner and the gate, and this state is double injection in the second mold It will achieve all stages of molding.

Second process (preparation process of secondary mold)

When the primary injection-molded product 1 is completed in the primary mold, the secondary mold is formed in the secondary mold.

This is the first injection by raising the deformation core (30a) to the upper part of the lower mold (10a) in accordance with the conditions of the primary injection molded product 1 in the state of separating the upper and lower molds (10a, 20a) of the secondary mold Be prepared to ensure that the part is seated in a safe and accurate position.

In this process, the cores 30a, which are installed in pairs to face each other in the cavity 41 of the lower mold 20a, are raised, so that their intervals are met so that the primary injection-molded product 1 can be seated. To do this.

That is, when the primary injection molded product 1 is placed on the core 30a using a manual method or a robot arm or the like, the primary injection molded product 1 is raised by a position set to maintain a gap that can be seated at the correct position.

3rd process (primary injection molded product seating process)

The primary injection-molded product 1 is seated using both cores 30a raised by the interval set in the above process.

In this process, when the primary injection-molded product 1 is placed on the upper end of both cores 30a, the protruding pieces protruding from the product are coupled to the ends of both cores 3a by force fitting, respectively, so as to be stably coupled at the correct position. This is done.

At this time, the gap between both sides of the raised core 30a is set slightly wider than the gap of the protruding pieces of the primary injection-molded product 1, so that the primary injection-molded product 1 can be easily seated without flow by elasticity. have.

4th process (preparation process of secondary injection molding)

After the primary injection molded product 1 is seated in the process, the raised core 30a is lowered to its original position, and thus the primary injection molded product 1 seated on the upper end of the core 30a is the lower mold 10a. Is tightly seated in the cavity 41.

That is, the cavity of the lower mold 10a is configured in the same shape as that of the lower surface and the outer surface of the primary injection molded product 1 so that the primary injection molded product 1 may be seated on the lower mold 10a. In this case, it sits very tightly without any gaps.

Particularly, in the final double-molded product, the protruding pieces such as the hinges and the hooks are seated very tightly without a gap inside the lower mold 20a, so that they are contracted or deformed by the heat of the molten resin supplied during injection molding. It has a feature to be prevented.

Subsequently, the movable die plate 200a is lowered to be coupled to the fixed die plate 100, and thus the upper and lower molds 10a and 20a are coupled without flow to form a cavity 41 therebetween.

At this time, the cavity 41 is to have a space for the second injection molding at the same time the first injection molded product (1) is inserted, the first injection molded product (1) to be inserted in the cavity 41 is tight Stable seating is maintained in a state in which only the part according to the double injection of the next process is exposed to the inside of the cavity 41.

5th process (2nd injection molding process)

After the upper and lower molds 10a and 20a are mutually combined as in the above process, secondary molten resin is injected into the empty spaces in the cavities 41 to perform secondary injection molding.

At this time, the molten resin supplied is supplied only in the cavity 41 in which the primary injection molded product 1 is seated, thereby double injection molding integrally with the primary injection molded product 1, and the resin of a different material from the primary injection molded product. Water, for example, primary injection molded products are opaque resins, whereas secondary resins are transparent resins, which can produce unique products due to different materials.

When the secondary injection molding is completed as described above, the movable die plate 200a is raised so that the upper and lower molds 10a, 20ad are completely separated, and the cavity 41 is opened to thereby open the secondary injection-molded product 2. Can be taken out.

In this extraction process, the core 30a is raised to the first stage to be prepared for the secondary injection molding, so that the double injection molded article can be taken out and the next work can be started.

Therefore, double injection molding is performed by sequentially performing a series of injection molding processes as described above, and in particular, even if a product is formed with protrusions projecting outwardly on either side of the double injection molded product, it can be easily injection molded without any deformation. Will have.

100,100a: fixed die plate 200.200a: movable die plate
300,300a: Eject plate 400, 400a: Support plate
500,500a: Movable side mounting plate 10,10a: Lower mold
20,20a: Upper mold 21, 21a: Sprue bush
30,30a: core 40,41: cavity
1: 1 Injection Molded Product 2: Second Injection Molded Product

Claims (2)

A double injection mold for integrally injecting two or more different synthetic resins, including:
The primary mold is a fixed die plate on which the lower mold is installed;
A movable die plate having an upper mold for opening and closing the lower mold by lifting and lowering operation;
An eject plate installed at a lower portion of the fixed die plate and supported by a supporting plate to move up and down;
A core which is axially coupled to the upper surface of the eject plate and formed in a rod shape and vertically installed inclined while penetrating into the cavity of the fixed die plate and the lower mold; And
The secondary mold may include a fixed die plate having a lower mold on which the primary injection molded article is mounted;
A movable die plate having an upper mold for opening and closing a cavity of the lower mold by a lifting operation;
An eject plate installed at a lower portion of the fixed die plate and supported by a supporting plate to move up and down;
A mold structure for double injection molding of a synthetic resin, characterized in that consisting of; the core is formed in a rod shape while being axially coupled to the upper surface of the eject plate, vertically inclined while penetrating into the cavity of the fixed die plate and the lower mold.
A double injection mold method for dual injection of two or more different synthetic resins integrally, comprising:
A first step of injecting molten resin into the cavity formed between the lower mold of the fixed die plate and the upper mold of the movable die plate in the primary mold to perform primary injection molding;
A second step of separating the upper and lower molds from the secondary mold and raising the core to the upper portion of the lower mold according to the conditions of the primary injection molded product so as to prepare the primary injection molded product to be seated in the correct position;
A third step of seating a first injection molded product on an upper end of the core raised to an upper portion of the lower mold;
A fourth step of lowering the core on which the primary injection molded product is seated to its original position so that the primary injection molded product can be closely seated in the cavity of the lower mold;
And a fifth step of injecting secondary molten resin into the cavity therebetween by coupling the upper and lower molds to each other to inject the secondary injection molded article.

Images