JPH0118857B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for manufacturing containers such as shipping boxes.
More specifically, the present invention relates to a container manufacturing method for easily and efficiently manufacturing containers such as returnable boxes with excellent strength and durability.

<Prior Art and Problems to be Solved by the Invention> Conventionally, containers such as mailable boxes have been provided that are made entirely of synthetic resin foam, as they are considered to be lightweight. There is. Containers made of such foam, if made of bead molding,
The strength of the corners is weak and they are easily damaged by even the slightest impact, so care must be taken when handling them.
For this reason, there has been a desire to increase the strength of the entire container without sacrificing weight reduction, but methods for manufacturing containers that maintain strength include molding at a low expansion ratio overall, or It is known to increase the thickness of each part.

However, if the entire container is manufactured by bead molding with a low expansion ratio, the consumption of raw materials will increase, and the manufacturing method that increases the wall thickness requires the use of a specially shaped mold, which reduces manufacturing costs. It leads to Atsupu. In addition, in order to avoid the negative effects in the case of , there is a method of laminating the side wall of the container to increase its strength, but with this method, it takes time and effort to integrate each laminated member, and if heat fusion is used, etc. However, there is a problem in that it requires technologically advanced technology.

<Purpose of the invention> The present invention has been made in view of the above-mentioned problems. For example, it is possible to easily and efficiently manufacture a container with excellent strength and durability, and to simplify the manufacturing process of the container. The purpose of the present invention is to provide a method for manufacturing containers such as shipping boxes that reduces costs.

<Means for Solving the Problems> In order to achieve the above object, the method for manufacturing containers such as return boxes of the present invention includes forming an inner body and an outer body that match the shape of the container using foamed sheets of synthetic resin. Then, a main core material made of synthetic resin foam is inserted into the space between the inner body and the outer body to partially close the space, and a foamed thermoplastic resin is inserted into the gap remaining after the interposition. The particles are filled, and after filling, heating is performed to heat and expand the resin particles in the gap to thermally fuse the resin particles to each other to form a sub-core material. Each of the exterior bodies is heat-sealed.

<Function> According to the method for manufacturing a container such as a mailbox having the above configuration,
A main core material made of synthetic resin foam is interposed in the space between the interior body and the exterior body to partially close the space, and the remaining gap after the interposition is filled with expandable thermoplastic resin particles. After filling, heating is performed to heat and expand the resin particles in the gap to heat-fuse the resin particles to each other to form a sub-core material, and each of the sub-core material, main core material, interior body, and exterior body. For example, the formation of a sub-core material that can partially increase the strength of the container can be performed at the same time in the heat-sealing step of integrating the inner body, the outer body, and the main core material.

<Example> Next, an example of the present invention will be described below with reference to the drawings. FIGS. 1A to 1D are explanatory diagrams showing the process of manufacturing a container such as a mailbox according to an embodiment of the present invention.

For convenience of explanation, first, a container such as a shipping box manufactured by the method for manufacturing containers such as shipping boxes will be briefly described with reference to FIG. 2.

In FIG. 2, the shipping box 1 includes an interior body 10 and an exterior body 20 made of a molded synthetic resin foam sheet.
The interior body 10 is made of a synthetic resin foam.
and a core material 30 interposed between the exterior body 20 and the exterior body 20. The core material 30 consists of a main core material 30a that occupies the main part, and a sub-core material 30b arranged at the upper edge of the container.
The main core material 30a is made of a foam having a lower expansion ratio than that of the main core material 30a (the expansion ratio of the main core material is approximately 50 times as compared to approximately 30 times that of the secondary core material). According to this, the above-mentioned shipping box 1 has excellent strength, especially at its upper edge.

In addition, the foamed sheets forming the interior body 10 and the exterior body 20 have a foaming ratio of about 10 times, and the main core material 30a and the sub-core material 30a are
The foaming ratio is lower than in case b, and the pressure resistance of the container surface is ensured. The thickness of the foam sheet is usually about 1 to 2 mm. In particular, since the interior body 10 and the exterior body 20 are made of synthetic resin foam sheets, there are no problems such as chipping of corners that occur when the entire body is made of foam molded by bead molding, and it also has elasticity. Because it is rich in minerals, it does not break easily.

The interior body 10, the exterior body 20, the main core material 30a, and the sub-core material 30b that constitute the shipping box 1 are heat-sealed and integrated with each other, and the interior body 1
0 and the exterior body 20 are also heat-sealed.

Note that a foamed polystyrene sheet is used as the synthetic resin foam sheet forming the interior body 10 and the exterior body 20, but a sheet or film made of high-impact polystyrene, double-stretched polystyrene, polyethylene, etc. is laminated on the foamed polystyrene sheet. In some cases, it may be used. Further, as the synthetic resin foam forming the main core material 30a and the sub-core material 30b, expanded polystyrene is used similarly to the interior body 10 and the like.

Next, a method of manufacturing the above-mentioned shipping box 1 according to an embodiment of the present invention will be explained with reference to FIGS. 1a to 1d.

As shown in FIG. 1a, an interior body 10 and an exterior body 20 are prepared which are made of foamed sheets and are molded in advance to fit the shape of the shipping box 1. In this case, the joint portion 40 of both the inner body 10 and the outer body 20 is provided so as to be located at the upper edge portion of the shipping box 1.

As a characteristic component of the method for manufacturing the above-mentioned shipping box 1, only the main core material 30a formed in advance by foam molding is inserted as a part of the core material 30, and the sub-core material 30b is formed by filling expandable thermoplastic resin particles before thermally fusing the interior body 10, main core material 30a, etc. by heating.

Of the prepared interior body 10, exterior body 20, and main core material 30a, the surface of the main core material 30a is wetted to adhere water, and then the main core material 30a is attached to the interior body 30a.
0 and the exterior body 20.
As a result, a part of the space is closed by the main core material 30a, but there is a gap S in the upper edge portion.
(See Figure 1b).

Next, the gap S is filled with expandable thermoplastic resin particles 60 with water attached to their surfaces (Fig. 1c
reference). The resin particles 60 are filled in through filling ports (not shown) formed in the inner body 10 and the outer body 20 in advance or afterwards.

Subsequently, the resin particles 60 are filled with the resin particles 60.
It is loaded into molds 50 and 50' that match the shape of the shipping box 1 (see Figure 1 d), and heated to mold 5 by heating means such as a heating furnace.
0.50' to heat the interior body 10, resin particles 60, etc. loaded therein. At this time, the resin particles 60 are heated and expanded, and are thermally fused to each other to form the sub-core material 30b, while closing the resin particle filling ports formed in the gap S, the interior body 10, and the like. At the same time, the contact surfaces of the interior body 10, the exterior body 20, the main core material 30a, the sub-core material 30b, etc. are thermally fused and integrated. This integration is achieved with good adhesion by steam heating by water adhering to the main core material 30a, etc., and by pressurizing the heat-fused surfaces of the main core material 30a, resin particles 60, etc. when they are heated and expanded. .

Note that filling of the resin particles 60 into the gap S is performed before loading the molds 50, 50' as described above, and also after loading the resin particles 60 into the molds 50, 50'. It may also be filled through the filling port.

As described above, the manufacturing of the shipping box 1 having the above configuration is completed, but the shape of the shipping box 1 is not limited to that shown in the drawings, but can be implemented in various shapes.
As shown in the figure, a grip part 7 is attached to the upper edge of the shipping box 1.
It is also possible to implement even if 0 is provided. In addition to the upper edge of the shipping box 1 as described above, the sub-core material 30b may be inserted at any arbitrary position depending on the purpose and the items to be stored.
As shown in the figure, if the lower edge is also interposed, it will prevent the corners from chipping, etc., and it will become durable without deformation. If you do this, it will be suitable for storing heavy objects.

Although the above manufacturing method uses a heating furnace as a heating means, there is also steam heating molding, in which the mold itself is provided with steam chambers, steam holes, etc., as in normal bead foam molding. This method may also be used.

Further, the present invention can be suitably employed for manufacturing containers other than the above-mentioned shipping box 1, such as containers such as portable cooler boxes.

<Effects of the Invention> As described above, the method for manufacturing containers such as shipping boxes according to the present invention includes forming a sub-core material that can increase the strength of a portion of the container, and forming an inner body, an outer body, and a main core material between each other. Since it can be carried out at the same time as the heat-sealing process for integrating, there is no need to prepare a secondary core material in advance, which simplifies the manufacturing process and reduces the manufacturing cost of containers. Formation of the sub-core material can also be easily performed.

Therefore, for example, constituent materials with different expansion ratios can be easily combined according to the degree of strength required, and containers such as shipping boxes with desired strength and durability can be manufactured easily and efficiently. .

[Brief explanation of drawings]

Figures 1 a to d are explanatory views showing the process of manufacturing a container such as a shipping box according to an embodiment of the present invention, Figure 2 is a perspective view of the shipping box, and Figures 3 to 5 are illustrations of other containers such as shipping boxes. It is a sectional view showing an example. 1... Shipping box, 10... Inner body, 20... Exterior body, 30... Core material, 30a... Main core material, 30b...
... Sub-core material, 40... Joint part, 50, 50'... Mold,
60...Expansible thermoplastic resin particles, 70...
Gripping part.

Claims (1)

[Claims] 1. A synthetic resin foam sheet in which an interior body and an exterior body conforming to the shape of the container are formed, and a space between the interior body and the exterior body is partially closed. By inserting a main core material made of resin foam, filling the gap remaining after the interposition with foamable thermoplastic resin particles, and heating after filling, the resin particles in the gap are heated and expanded. A method for producing a container such as a mailbox, comprising: forming a sub-core material by heat-sealing particles to each other, and heat-sealing each of the sub-core material, the main core material, the inner body, and the outer body. 2. The mailbox according to claim 1, wherein heating is performed after filling the expandable thermoplastic resin particles into the gap using a mold that matches the shape of the container, and the filling is performed before loading into the mold. A method for manufacturing containers such as 3. Heating performed after filling the expandable thermoplastic resin particles into the gap is performed using a mold that matches the shape of the container, and the filling is performed after loading into the mold and before heating. Method of manufacturing containers such as shipping boxes. 4. The method of manufacturing a container such as a mailbox according to claim 1, wherein water is previously attached to the surfaces of the main core material and the expandable thermoplastic resin particles serving as the sub-core material.