JPS603065Y2 - Composite container made of paperboard and plastic sheet - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a composite container of paperboard and plastic sheet.

Composite containers made of paperboard and plastic sheets are often used as tabletop containers for margarine and the like.

Generally, as shown in Fig. 1, the bottom part 21 has inner end parts 22, 22 at both upper and lower ends, both side parts 23, 23 continuous to the left and right of the bottom part 21, and an extension thereof, and both end faces are butted together. End surface outer part 2 forming
A blank 2 in which 4A, 24A and 24B, 24B are integrally punched out of paperboard is pushed into the die 4, and the above-mentioned end surface outer portions 24A and 24A and 25B and 25B are butted on the outside of the end surface inner portions 22.22. A carton is preformed as shown in Figure 2, and a sheet 3 of heated plastic, such as polystyrene, is placed on top of it, and this is pressed against the inner surface of the carton by the force of vacuum or compressed air, as shown in Figure 3. It is produced by forming a molded body 11 with a cross section and subsequently trimming the edges.

Since the surface of the paperboard that will become the inside of the container is coated with a heat sealing material, the plastic sheet becomes integral with the carton at the same time that the inner end portion 22 and outer portion 24 are attached.

This composite container has the advantage of being able to print in a flat state before punching out the paperboard, so there are no restrictions on printing, and the strength of the paperboard can be utilized.

However, as you can easily imagine from the above manufacturing process, the plastic sheet is the thinnest at the corners of the container, and pinholes often form at the corners, allowing air and bacteria to enter and destroy the contents. to transform.

Therefore, it is strongly desired to prevent the occurrence of pinholes, especially when making food containers.

As a measure to meet this demand, the present inventor proposed that in order to prevent the occurrence of pinholes, the plastic sheet should be prevented from becoming locally thin, and in order to do so, the part that rises from the bottom to the side wall should have a shape that is sharply bent. I realized this and came up with this idea.

The composite container of paperboard and plastic sheet of the present invention consists of the paperboard blank 2 and the plastic sheet 3 as described above.
In order to achieve a gradual transition from the bottom surface to the side wall in a complex with
at least four corners of the container 1, transitioning from the bottom to the side walls;
It is characterized by providing an inclined surface 25 having a gentle inclination both to the bottom surface and to the side wall.

This inclined surface can be easily formed by designing a blank as shown in FIG. 4B and providing tongues serving as inclined surfaces at the corners.

That is, the geometry of the tongue during carton preforming and vacuum or pressure forming is as follows:
It can be set so that it stops in contact with the side wall at an appropriate position as shown in .

Various modifications are possible to the composite container of the present invention.

First, it is conceivable to provide the above-mentioned inclined surfaces not only at the four corners but also on the entire ridgeline portion, and for this purpose, the configuration shown in FIG. 5 may be adopted.

In this case, the inclined surface 26 is provided over the entirety of a pair of opposing ridgelines (both end portions in the figure) of the container.

In this embodiment, if you want to increase the safety of the container, the 6th
As shown in the figure, it is recommended to provide a folded adhesive portion 29 of the paperboard on a pair of opposing edges (in the figure, on both sides) that do not have an inclined surface 26.

If it is desired to maximize the effect of the present invention by providing this slope across the entire bottom of the container, it can be applied across all four corners and four ridge lines, as shown in Figure 7.
Inclined surfaces 25, 26 and 27 can also be provided.

All of the above embodiments relate to approximately rectangular or square containers in which the corners are formed with a slight radius, but the present invention can also be applied to octagonal containers in which the four corners of a square or rectangle are rounded. .

In the example shown in FIG. 8, an inclined surface 28 transitioning from the bottom surface to the side wall is provided at the corner portion of the octagon.

As shown in this example, the present invention can be applied to composite containers of paperboard and plastic sheets by simply making a slight change to the shape of the blank punched from the paperboard, without affecting other processes at all, and by attaching pins to the plastic sheet of the container. It is possible to provide a composite container that effectively prevents the occurrence of holes.

[Brief explanation of drawings]

Figures 1 to 3 show the manufacturing process of a composite container according to the prior art (the container of the present invention is also manufactured by the same process in principle), Figure 1 is a plan view of a blank punched from paperboard, Figure 2 is an exploded perspective view of a part of the carton formed by preforming it in a mold, and Figure 3 is a cross-sectional view of the molded product obtained by overlaying a plastic sheet on top of it by air pressure molding and integrating it. It is. FIG. 4 is a diagram for explaining a typical example of the present invention, in which A is a perspective view of a part of a carton in a preforming state, B is a plan view of a blank for providing this, and C is a
FIG. 5, 6, 7, and 8 are perspective views similar to FIG. 4A for explaining other aspects of the present invention. 1...Composite container, 2...Blank, 3
...Plastic sheet, 21...Bottom part, 22...Inner end part, 23...
...Side surface portion, 24A, 24B...End surface outer portion, 25, 26, 27, 28...Slope surface.

Claims (1)

[Scope of utility model registration request] A bottom surface portion 21 having inner end portions 22.22 at both upper and lower ends, double-sided portions 23.23 continuous to the left and right, and outer end portions 24A, 24A, 24B, 24B that are on the extension thereof and form both end surfaces by butting. In a container 1 made by integrally forming a blank 2 obtained by punching out a paperboard and a plastic sheet 3 by vacuum or pressure forming, at least four corners of the container 1 transition from the bottom to the side wall. A composite container made of paperboard and a plastic sheet, characterized in that inclined surfaces 25, 25, 25, 25 are provided with very gentle inclinations.