JPH0380005B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for manufacturing a compact container, and more specifically to a method for integrally welding a hinge portion of a container body and a lid body. .

<Prior Art> As a compact container in which a lid body and a hinge portion of a container body are integrally formed, a compact container made of an olefin resin such as polypropylene is known. This known compact container is extremely inexpensive and has excellent hinge properties, but the olefin resin is too flexible as a container, and there is a difference in molding shrinkage depending on the flow direction of the resin, which may cause warping of the molded product. They tend to cause sink marks and are easily scratched on the surface, and have many deficiencies for compact containers that place emphasis on luxury, and are only partially used as low-priced compact containers.

A solution to the above-mentioned material defects is to use styrene-based resin, but styrene-based resin has no bending flexibility and cannot produce a hinge effect. For this reason, a hinge mechanism is generally used in which pin holes are provided in the lid and the container body, respectively, and these are connected using metal pins.

<Problems to be Solved by the Invention> Therefore, in conventional compact containers using styrene resin, the hinge part has a shape that protrudes from the outer wall surface, which not only looks unsightly, but also makes the molding mold difficult to use. The process is also complicated, and it is necessary to assemble the lid and the container body after molding, which increases manufacturing costs.

The present invention has been made in view of the above-mentioned problems, and its purpose is to integrally hinge a container body and a lid made of styrene resin without protruding a hinge part as in the past. The present invention provides a method for manufacturing a compact container.

<Means for solving the problem> According to the method of the present invention that achieves the above object,
A first recess for forming a container body and a second recess for forming a lid body are arranged closely in parallel, and both adjacent ends of the first and second recesses are enlarged. In a mold that communicates with a cavity,
A sheet material having flexibility in bending in a direction perpendicular to the enlarged space is supplied, and an outer sleeve-like cutter member and an inner plate member are simultaneously slid within the enlarged space to punch out the sheet material and the punched out part. Move the sheet piece close to the adjacent ends of both the recesses, and further slide only the outer sleeve-like cutter to make the sheet piece straddle the adjacent ends of the recesses to form a U-shape. The container is held in the same shape, and molten styrene resin is injected into the first and second recesses, and the sheet pieces are integrally welded at the hinge portions of the container body and lid.

<Examples> Specific examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a compact container manufactured by the method of the present invention, in which 1 represents a container body for storing cosmetics, etc., and 2 represents a lid. The container body 1 and the lid 2 are hinged to each other at their rear ends, and a protrusion 3 is formed on the front end surface of the container body 1.
A hook-shaped claw piece 4 formed on the front edge of the lid body is connected to the lid body, so that both of them occupy a closed position.

In the compact container described above, both the container body 1 and the lid 2 are made of styrene resin, and the container body 1 and the lid 2 are integrally welded to a bendable sheet piece 5 at the rear end. This allows the lid 2 to be hinged to the container body 1 so as to be openable and closable.

As shown in FIG. 1, a sheet piece 5 is bent into a horizontal U-shape and integrally welded between the opposing end surfaces of the container body 1 and the rear end of the lid 2, and each end of the U-shape A compact container is shown in which the container has a flange shape and is embedded in the opposing inner corner portions of the container body 1 and the lid 2.

Various types of sheet pieces 5 are conceivable, but as an example of chemically welding the sheet piece 5 to the container body 1 and lid 2, as shown in FIG. A sheet piece that has a single layer structure of vinyl or urethane synthetic resin and has refraction flexibility, or a core material that has refraction flexibility and is made of woven fabric, aluminum, synthetic resin film, synthetic leather, etc. as shown in Figure 2b. The core material 6 may be coated with an adhesive layer 7, preferably a heat-sensitive adhesive layer such as hot melt, or a synthetic resin film compatible with styrene-based synthetic resin may be used as the core material 6, as shown in FIG. 2c. 8 is used as an integral three-layer structure with adhesive 9. Preferably, as shown in FIG. 3a, the sheet piece for the butterfly is formed from a woven fabric 10 with multiple mesh weave, and molten resin is flowed between the meshes of the woven fabric during injection molding of the container body 1 and the lid 2. The cloth 10 is integrally embedded in the container body and the hinge part of the lid body to form a hinge. FIG. 3b shows a sheet piece in which a woven fabric 10 of multiple mesh weave is lined with a core material 11 made of synthetic leather, etc., and this woven fabric layer 10 serves as the hinge of the container body 1 and the lid 2 as in the above case. It will be buried in the department.

In the compact container having the above structure, the container body 1 and the lid 2 are made of a styrene-based resin that gives a high-class feel, and are hinged with a single sheet piece, so that the shape of the periphery is It is possible to create a compact container with a simplified and neat shape. Moreover, since the sheet piece for the butterfly attachment is integrally welded to the lid and the container body, the lid can be opened and closed stably without fear of peeling.

The method of the present invention for manufacturing the compact container as described above will be explained with reference to FIGS. 4 to 7. These figures show an injection mold. This mold is composed of a female mold 12 and a male mold 13. Between the male and female molds 12 and 13, there is an inverted concave lid molding space 14. A container body molding space 15 having an inverted concave shape is formed. In the female mold 12 on the center top of each space 14, 15, there is a runner 1 for injection molding.
6a, 16b and sprues 17a, 17b are bored, while the male die 13 has protruding pins 18a, 18b for releasing the molded product and an inclined pin 20 for pulling out the hook-like uneven groove 19. ing.

Mutually adjacent ends 14a, 15a of the lid body forming space 14 and the container body forming space 15 are separated by a partition wall 21, and these ends 14a, 1
5a communicates with an enlarged cavity 22 passing through the male mold 13 toward the female mold 12. Note that the tip of the partition wall 21 partially protrudes into this enlarged space 22.

An insertion hole 23 is formed in this enlarged space 22 in a direction perpendicular thereto, and a sheet piece 5 as shown in FIG. 2 or 3 is inserted into this insertion hole 23. Furthermore, an outer sleeve-shaped cutter member 24 and an inner plate member 25 are slidably disposed within this enlarged space 22, and this cutter member 2
4 and the plate member 25 occupy a position below the sheet piece 5 during a pause in the molding cycle.

When the molding cycle starts, as shown in FIG. 5, the outer cutter member 24 and the inner plate member 25 simultaneously slide within the enlarged space 22, punching out the sheet piece 5 and using it for forming the lid. Mutually adjacent ends 1 of the space 14 and the container body forming space 15
4a and 15a. At the position where this sheet piece 5 abuts against the partition wall 21 between the ends 14a and 15a, the inner plate member 25 stops, and as shown in FIG. 6, the outer cutter member 24
only the space portion 1 rises inward, and the sheet piece 5 is moved into both spaces 1.
It is held so as to straddle the adjacent end portions 14a and 15a of 4 and 15 in a U-shape. Next, as shown in FIG. 7, the styrene resin melted at 230 to 250°C is injected into the runners 16a and 16 of the female mold 12 using an injection molding machine.
The liquid is injected and filled into the lid forming space 14 and the container body forming space 15 through the sprues 17a and 17b from b. Since this injected styrene resin is filled at high speed and high pressure, the sheet pieces 5 held in a U-shape at the ends 14a and 15a of both the spaces 14 and 15 are placed on both inner surfaces of the sleeve-like cutter member 24. and the top surface of the inner plate member 25, and when the sheet piece 5 is made of a material as shown in FIG.
It is integrally welded with the resin filled in 4 and 15.

Further, when the sheet piece 5 is made of the material shown in FIG. 3, the injected resin flows into the multiple mesh spaces and is integrally welded with the resin filled in the spaces 14 and 15. be done.

When the filled molten resin solidifies as the mold is cooled, molding shrinkage occurs and the mold adheres tightly to the male mold 13. After that, the female mold 12 is removed, the molded parts attached to the male mold 13 are ejected, and the pins 18a, 18b and the inclined pin 20 are removed.
By protruding at , the molded product in which the container body 1 and the lid 2 are hinged by the sheet piece 5 can be released from the mold. Next, after the outer sleeve-shaped cutter member 24 and the inner plate member 25 are lowered as shown in FIG. 4, the belt-shaped sheet material 5 is rolled up and moved, thereby completing the forming process.

<Effects> As described above, according to the method of the present invention, when molding the container body 1 and the lid body 2 made of styrene resin, the sheet piece 5 that hinges them inside the molding mold can be formed very easily and easily. Since it is securely welded and is made of styrene resin, it is possible to efficiently produce compact containers that are beautiful and have a good appearance without the hinge portion protruding outwardly. In addition, since the butterfly attachment sheet piece 5 is welded to the rear end of the lid and the container body in a U-shape,
This hinge will be strong.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged vertical sectional view of a compact container manufactured according to the present invention, FIGS. and FIG. 3b is a sectional view showing another sheet piece for a butterfly, and FIGS. 4 to 7 are longitudinal sectional views showing the method of the present invention in the order of steps. 1... Container body, 2... Lid, 5... Sheet piece, 12... Female mold, 13... Male mold, 14...
Space for forming lid body, 15... Space for forming container body, 22... Enlarged space, 24... Outer sleeve-shaped cutter member, 25... Inner plate member.

Claims (1)

[Claims] 1. A first recess for forming a container body and a second recess for forming a lid body are arranged adjacently in parallel, and both adjacent ends of the first and second recesses are arranged in parallel. In a mold communicating with an enlarged cavity, a sheet material having flexibility in bending in a direction perpendicular to the enlarged cavity is supplied, and an outer sleeve-like cutter member and an inner plate member are simultaneously slid within the enlarged cavity. to punch out the sheet material and move the punched sheet piece near the adjacent ends of both recesses, and further slide only the outer sleeve cutter to punch out the sheet material in the recesses. The sheet piece is held in a U-shape across the adjacent ends, and molten styrene resin is injected into the first and second recesses to integrate the sheet piece at the hinge part of the container body and lid body. A method for manufacturing a compact container, characterized in that the container is made by welding.