JPS61258717A - Molding of multi-color resin container - Google Patents

Abstract

PURPOSE:To make at least the bottom of a container of two kinds of synthetic resins, by injecting the 1st resin in a cavity of the surrounding wall and a groove at the forwarding position of a sliding core and then injecting the 2nd and 3rd resins to the one side and the other side of the bottom cavity respectively at the retreating position of the sliding core. CONSTITUTION:A core mold 40 consists of the 1st sliding core 42 forwarding/ retreating freely and the 2nd core 43 having a groove 44 to form a partition wall 23 at the extreme point in a base core 41 to be faced with a cavity mold 30. The 1st resin P1 colored in a required color is injected in the surrounding cavity C1 and the groove 44 at the forwarding position of the sliding cores 42, 43 and the 2nd and 3rd resins P2, P3 colored in another color and having compatibility with the 1st resin are injected in a bottom cavity C2 from the pouring gates G2, G3 at the retreating position of the sliding cores 42 and 43 and at the same time the 4th resin P4 of another color is injected in a top cavity C3 from a pouring gate G4.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to various parts (peripheral wall part,
The present invention relates to a method for molding a multicolored resin container in which the bottom plate portion, etc.) is molded using different colored resins.

``Conventional technology'' For example, as a synthetic resin container for storing cosmetics, etc.
As shown in FIG. 1, a structure in which a container body 1 and a lid 2 are integrally connected by a thin hinge 3 is known. In this type of container, for example, the container body 1 and the lid 2 are molded from synthetic resins of different colors in order to give the container a sense of luxury and a change in color.

12 to 13 show a conventional example of the molding method, in which a container cavity 6, a lid cavity 7, and a hinge cavity 8 are formed between a cavity mold 4 and a core mold 5, and a As shown in FIG. 12, in a state where the container cavity 6 and the lid cavity 7 are separated by the sliding pin 9, the first composite state P is released from the first sprue 10.
, and then, as shown in FIG.
11, a second synthetic resin P of a different color from the first synthetic resin is injected from the second sprue 11, thereby forming a two-color synthetic resin container having the structure shown in FIG. This is the way to get it.

``Problems to be solved by the invention'' However, in such conventional molding methods,
Due to the structure of the mold used for this, basically the molding of containers in two colors is the limit, and it is impossible to integrally mold containers with more different colors. There is a problem in that it is not possible to fully satisfy this type of container, which is also important. In addition, in this conventional mold, as a means for separating the container cavity 6 and the lid cavity 7, the boundary portion between the container cavity 6 and the hinge cavity 8 (the portion corresponding to the peripheral wall of the container body) is inserted into the cavity. Due to the structure in which the sliding bin 9 is moved forward and backward, there is a problem in that depending on the wall thickness and cross-sectional shape of the peripheral wall of the container to be molded, it may not be possible to move the sliding bin 9 forward and backward. There was also.

Therefore, according to the present invention, containers having two or more different colors can be easily molded by integral molding, and this can be realized by extremely easy means from the viewpoint of the structure of the mold. Furthermore, the present invention aims to provide a molding method that is not affected by the shape of the container to be molded.

"Means for Solving the Problems" The molding method according to the present invention includes forming a bottom plate cavity and a peripheral wall cavity in a mold for molding the container body,
A core mold constituting the mold is provided with a sliding core that can move forward and backward into the bottom plate cavity, and a groove for forming a partition wall that partitions the storage section is formed on the tip surface of the sliding core,
At the forward position of the sliding core, the first synthetic resin is injected into the groove of the peripheral wall cavity, and then, at the retracted position of the sliding core, the first synthetic resin is injected into one side of the bottom plate cavity divided by the partition wall. At least the bottom plate portion of the container body is molded from the same type of synthetic resin by injecting the second synthetic resin and the third synthetic resin.

Example 1 An example of the present invention will be described below with reference to the attached drawings.Before explaining the molding method of the example, the results obtained by this molding method will be explained with reference to FIGS. 7 and 8. The structure of the multicolored resin container will be explained below.The container according to this illustrated example basically has a container body 20, a lid 21, and a thin hinge 22 that integrally connects these. 20 storage compartments are divided into two storage compartments A and H by a partition wall 23 extending back and forth.
The partition wall 23, the peripheral wall part 20a1, the peripheral wall part 21a of the lid body 21, and the thin hinge 22 are made of the first synthetic resin P1, and the bottom plate part 20b of the storage part A of the container body 20 is made of the first synthetic resin P1. 2 of the synthetic resin P, and is formed of the other synthetic resin P, and is further formed of the top plate part 2 of the lid body 21.
1b is formed of a fourth synthetic resin P4, and the first, second, third and fourth synthetic resins PI, P2, P
, and P4 all have different colors to form a four-colored resin container, which is different from the conventional container.

Next, examples of molding equipment (molds) suitable for carrying out the method for molding this four-color resin container are shown in Figures 1 to 4.
This will be explained with reference to the figures. In these figures, reference numeral 30
is a cavity type, and 4° is a core type. Core type 4
0 is the base core 4 which is matched with the cavity mold 30 [
and a first sliding core 42 and a second sliding core 43, which are provided on the base core 41 and can move forward and backward into the cavity. And both sliding cores 4
2.43 is in the forward position as shown in FIG. 3, in this mold there is a mold for molding the peripheral walls 20a, 21a of the container body 20 and the lid body 21, and the thin hinge 22. When the surrounding wall cavity is in the retracted position as shown in FIG. 4, in addition to the surrounding wall cavity C1, there is also a bottom plate cavity Ct for molding the above-mentioned bottom plate parts 20b, 20c, etc., and a top plate. The top plate cavities C3 for molding the portions 21b are respectively formed.

In addition, in this embodiment, as shown in FIGS. 1 and 2, a partition wall 23 is provided on the tip surface (upper surface) of the second sliding core 43.
A groove 44 for molding the groove 4 is formed in communication with the peripheral wall cavity C3.
4 are placed between them and open into the bottom plate cavity C7, and a fourth gate G4 opens into the top plate cavity C3, and each of these gates G, , Gt, G3, G, are each connected to their respective injection machines (not shown) via their own runners.

In order to mold the containers shown in FIGS. 7 and 8 using the molding apparatus configured as described above, first, the 11th and 2nd sliding cores 42 and 43 are positioned in the forward position shown in FIG. A first synthetic resin P1 made of, for example, polypropylene resin colored in a desired color is injected from the first sprue G1 into the peripheral wall cavity C8 and the groove 44, and then the sliding cores 42 and 43 are injected into the peripheral wall cavity C8 and the groove 44. After placing it in the retracted position shown in Figure 6,
Second and third synthetic resins P7 and P3, each made of the same or different resin that is compatible with the first synthetic resin P1, are colored in different colors from t and G3 into the second and third sprues. A fourth synthetic resin P4 having a different color from any of the first to third synthetic resins is injected into the bottom plate cavity C7, and further in parallel thereto from the fourth sprue G into the top plate cavity C3.
Eject inside.

Through this operation, in the cavity for molding the container body 20, the peripheral wall 20a of the container body 20 and the partition wall 23 are first formed of the same synthetic resin P, and then divided by the partition wall 23. bottom plate cavity C
A bottom plate portion is formed by the second synthetic resin P on one side of the holder 1, and a bottom plate portion is formed on the other side by the third synthetic resin P.

Note that in this embodiment, the partition wall 23 is actively used as a separation wall when forming the bottom plate portion as described above.
For example, assuming that the wall thickness of the partition wall 23 is 1.5 mm, even if the second sliding core 43 is lowered by the thickness of the bottom plate, at a shrinkage rate of 16/1000, it will be 0 on both sides. Since it is calculated that the shrinkage will be .024+nm, it is possible to cut off between the groove 44 of the descended second sliding core 43 and the partition wall 23, and therefore there is no need to consider the breakage caused by the resin in the bottom plate, and its molding There is no problem.

After each synthetic resin is injected in this manner, the cavity mold is opened after cooling it for the necessary time, and the sliding core is then advanced to remove the mold. The four-colored synthetic resin containers shown in the figures are molded.

Here, the second, third and fourth synthetic resins Pt5P3,
If synthetic resin of the same color is used for P, the bottom plate parts 20b, 2
A container is formed in which the container 0c and the top plate portion 21b are the same color, and the other parts are different in color.

Thus, according to this embodiment, by simply sliding both the sliding cores 42 and 43 into their forward and backward positions, the four
It is possible to form the four cavities necessary to obtain colored containers, and its structure and operation are reasonable. Therefore, the thickness and cross-sectional shape of the peripheral wall of the container to be molded can be varied in various ways. Even when molding a container or the like, it is possible to easily mold a cavity that fully corresponds to the mold.

Furthermore, as in the embodiment, when the first sliding core 42 and the second sliding core 43 are configured separately, the bottom plate portion 2
There is an advantage that the wall thickness of 0b, 20c and the top plate part 21b can be adjusted freely as necessary, and the sliding core 42.4
3 can also be used for ejecting molded products.

Next, referring to FIGS. 9 and 10, another example of the molding device (mold) used to carry out the molding method of the present invention will be explained. In this example, the second sliding core described above is 43 is deformed to form a groove 44° that forms the partition wall 23 into a tapered shape that expands outward.
The lIF 44'' is formed deeper than the groove 44 as a whole by approximately the thickness of the bottom plate. Therefore, when the second finger core 43 is lowered, the formed partition wall 23 and the groove 44
° A space is created between the
, when the third synthetic resins P, , P3 are injected, each synthetic resin P1, P enters this space, and the partition wall 23 can be divided into approximately two colors by the synthetic resins P t , P 3. It is possible.

According to this embodiment, the partition wall 23 can be formed in two colors, so that when different types of contents are stored in the storage sections A and B, the contents can be easily distinguished. ,
It has advantages such as ease of use.

Further, in each of the embodiments described above, the first and second sliding cores are constructed separately, but it goes without saying that they may be constructed integrally.

``Effects of the Invention'' As explained above, according to the present invention, containers having two or more different colors can be easily molded by integral molding, and this can be done easily due to the structure of the mold. It can be realized by extremely easy means in terms of moldability, etc., and has excellent effects such as being able to obtain a good method for molding multicolored resin containers that is not affected by the shape of the container to be molded. play.

[Brief explanation of drawings]

1 to 8 show an embodiment of the present invention,
Figures 1 and 2 are sectional views showing a mold for molding the container body, Figures 3 and 4 are sectional views of a molding device, and Figures 5 and 6 are sectional views showing a molding method, respectively. The sectional views shown for explanation, FIGS. 7 and 8, show the molded container, and FIG. 7 is a perspective view, and FIG. 8 is a perspective view.
The figure is a sectional view, FIGS. 9 and 10 are sectional views of other embodiments of the molding apparatus, and FIGS. 11 to 13 are sectional views of a conventional molding method. 12 and 13 are cross-sectional views of the container, respectively. 20...Container body, 20a, 21a...
・Peripheral wall part, 20b, 20c... Bottom plate part, 21b
...Top plate section, 21... Lid body, 22...
... Thin hinge, 23 ... Partition wall, 30.
...Cavity type, 40...Core type, 4
1... Base core, 42... First sliding core, 43... Second sliding core, 44...
・Groove, P,...First synthetic resin, P,...
...Second synthetic resin, P3...Third synthetic resin, P4...Fourth synthetic resin, CI...
Peripheral wall cavity, C1...Bottom plate cavity, C
3...Top plate cavity, A, B...Storage section. Figure 1 Figure 3 Figure 4 Figure 5 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] A synthetic resin container comprising a container body having a partition wall in its storage area, a lid body covering the storage area of the container body, and a thin hinge integrally connecting these parts, each part of which is molded from a different colored resin. The method comprises forming a bottom plate cavity and a peripheral wall cavity in a mold for molding the container body, providing a core mold constituting the mold with a sliding core that can freely move forward and backward into the bottom plate cavity, and A groove for forming a partition wall is formed on the tip surface of the sliding core, a first synthetic resin is injected into the peripheral wall cavity and the groove at the forward position of the sliding core, and then the sliding core is In the retracted position, the second synthetic resin is injected into one side of the bottom plate cavity divided by the partition wall, and the third synthetic resin is injected into the other side, so that at least the bottom plate part of the container body is coated with two types of synthetic resin. A method for molding a multicolored resin container, characterized by molding.