JPH0239978Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Application) The present invention relates to an improvement in a cup-shaped container that is heat-sealed with a lid made of a metal foil/plastic film laminate, and particularly to an improvement in the opening structure of the container.

(Prior art) A cup-shaped container is heat-sealed with a lid made of a metal foil/plastic film laminate.
Today, they are widely available on the market as packaging containers for instant foods. On the upper rim of this type of container,
In order to satisfy the strength level specified in the heat sealing strength test method based on the Ministry of Health and Welfare Notification No. 20, an annular sealing rib is generally provided, and this rib part has a strong thermal bond with the sealing laminated lid member. is being carried out. Therefore, when trying to remove the lid member for use, it becomes difficult to peel it off, and if the lid member is not peeled off slowly and carefully, the lid member may be torn or twisted during peeling, which may confuse the user. many. This drawback is particularly noticeable in the case of heat-sterilized packaging which requires strong adhesive strength.

Therefore, in order to improve this shortcoming to some extent,
There is a proposal to provide a sharp protrusion (coracoid) on a part of the rib, but at the beginning of peeling, a large shearing force is concentrated at the dot-like bond between the tip of the coracoid and the lid member. Not only is there a risk that the bonded portion may not be able to withstand the force and be torn from both sides, but it is still difficult to peel off the lid member other than the coracoid portion.

(Objective) The object of the present invention is to solve the above-mentioned problems in cup-shaped containers made of thermoplastic plastics, and to provide a cup-shaped container whose lid member can be easily peeled off when in use.

(Structure) In order to achieve the above object, the present invention provides a cup-shaped container in which a ring-shaped rib surrounding the upper edge of the main body made of thermoplastic plastic is provided with a coronoid for opening. , a structure in which protrusions are provided alternately with adjacent rib portions so as to have different widths and/or heights is adopted.

The above configuration includes the following three types of formats.

: A type in which each part of the adjacent ribs has a different width. : A type in which each part of the adjacent ribs has a different height. : A type in which each part of the adjacent ribs has a different width and height. Fig. 1 is a plan view of an example of a container belonging to the above types, Fig. 2 is a partially enlarged sectional view taken along line XX of Fig. 1 (however, the height of the ribs is exaggerated), and Fig. 3 teeth,
A partially enlarged perspective view of the flange portion of the container shown in FIG. 1 viewed diagonally from above (same as above); FIG. 4 is a plan view of an example of the container 1' belonging to the type;
6 is a perspective view similar to FIG. 3; FIG. 7 is a plan view of an example of container 1'' belonging to the type; FIG. FIG. 9 is a partially enlarged sectional view taken along Z-Z, and is a perspective view similar to FIG. 3.

In the container 1 of this type, the contour lines of the rib 3 whose reference plane is the plane of the flange 2 are wavy (see FIG. 1). Furthermore, experimentally, it is preferable that the widths of the maximum width part and the minimum width part of the rib are about 2 mm and 1 mm, respectively.

In this type of container, the planar shape of the rib 3 is linear (see FIG. 4), but the side surface shape is step-like (see FIG. 5). In this case, the difference H-h between the height H to the top of the main rib and the height h to the saddle is
It is preferably 0.2 to 0.3 mm.

In the type container 1'', the contour line with the plane of the flange 2 of the rib 3 as the reference plane is wavy (7th
(see figure), and the ridgeline of the rib also becomes wavy (see figure 8). In this case, the widths of the maximum width part and the minimum width part of this rib are experimentally determined to be about 2 mm and 1 mm, respectively, and the difference between the height H to the top of the rib and the height h to the saddle part H- It is preferable that h is 0.2 to 0.3 mm.

The containers 1 to 1'' of the present invention are made of polystyrene, polyethylene, polypropylene, polyester, ethylene-vinyl acetate copolymer, and other plastic materials that can be molded by general molding methods for thermoplastic resins such as vacuum or pressure molding, compression molding, or injection molding. It is made into a cup shape of any shape such as a single-layer or multi-layer truncated square pyramid shape, truncated conical shape, truncated elliptic conical shape, etc., and the mouth edge of the cup extends horizontally to the outside to form a flange portion 2. The upper flange portion 2 has an annular rib 3 having the shape described above that protrudes upward. A (coracoid) 5 is formed to form a sharp tip 5a.Both skirts of this obtuse-angled protrusion are preferably curved in an asymptotic line toward the annular rib portions on both sides.

(Function) The above container, for example, as shown in Fig. 10,
It is placed on the upper edge 8a of the metal sealing frame (mold) 8 (the material to be filled 7 is filled before and after this), and after the lid material 6 is placed on it, the heating plate 9 is equipped with a heating wire inside. Pressed under heat. At this time, the main container 1
1'' has a difference in the width and/or height of the rib 3 portion, resulting in a difference in adhesive force with the lid member 6 partially.

That is, in this type of container, the top surface width B of the rib 3 at the adhered portion is wide at the wide rib section 3b in FIG. 11 and narrow at the narrow rib section 3n in FIG. 12. Therefore, the adhesive force between the two has a relationship of 3b>3n. In addition, in the type of container, the high rib part 3h
Naturally, the adhesive strength in the lower rib portion 31 is greater than that in the low rib portion 31. Furthermore, even in containers of this type, the high rib portion 3
There is a similar difference in adhesive strength between h and the low rib portion 31 as in the type.

As described above, in the container of the present invention, there is a regular difference in the adhesive strength between the rib and the lid material, and as a result, the shear force at the time of peeling is applied shockingly from the peeled part to the unpeeled part. As a result, peeling progresses as if tearing thick perforated cardboard. Moreover, since the areas with strong adhesive force and the areas with weak adhesive force exist symmetrically with respect to the direction of action of force P (see Figure 18), the lid member is peeled off evenly, making it difficult for twisting to occur. Due to these combined actions, the overall peeling operation is significantly easier than in the conventional method. As shown in FIG. 1, FIG. 4, and FIG. By partially lowering the adhesive force between the part and the lid member, the peeling operation becomes easier.

(Example) Hereinafter, the mode of implementing the invention will be explained using examples, but these are of course for illustrative purposes and are not intended to limit the spirit of the invention.

FIG. 17 is a cutaway perspective view showing an example of a package using the container according to the present invention.

The container 1 is made from a sheet material of impact-resistant polystyrene using vacuum forming means into a truncated square pyramid shape with rounded edges, and the rim extends horizontally outward and has a rounded shape. A flange portion 2 is formed, but only one corner of the latter forms a triangular photographed portion 4.

Wide and narrow ribs 3 similar to those in Figures 1 to 3
bulges out in an annular shape on the surface of the flange portion 2,
The coracoid part 5 protrudes at an obtuse angle in the area of the photographing part 4.
form. Both hem portions of the coracoid portion 5 form an asymptotic line and are connected to the ribs 2 on both sides.

After the object to be packaged 7 is placed in the container 1, the lid member 6 is thermally bonded to the entire rib 3 including the coracoid part 5 by the method shown in FIG.

To open the above package, peel off the lid member 6 at the photographed part 4 as shown in Fig. 18, photograph both the photographed part and the corresponding lid member, and apply a shearing force P in the direction of the arrow. to complete the peeling. As already explained, in this case, since there is a difference in adhesive strength between the rib 3 and the lid member 6 in some parts, peeling is extremely easy and there is no risk of tearing the lid member in the middle.

(Effects) As explained above, although the present invention has an extremely simple structure, it facilitates the opening of the heat-sealed lid of this type of container and eliminates the risk of accidentally damaging the lid member during opening. This provides great benefits to users.

[Brief explanation of drawings]

Fig. 1 is a plan view of an example of a container belonging to the type of the present invention, Fig. 2 is a partially enlarged sectional view taken along line XX of Fig. 1 (however, the height of the ribs is exaggerated), and Fig. 3 is a
A partially enlarged perspective view of the flange portion of the container shown in FIG. 1 viewed diagonally from above (same as above); FIG. 4 is a plan view of an example of the container 1' belonging to the type;
6 is a perspective view similar to FIG. 3; FIG. 7 is a plan view of an example of container 1'' belonging to the type; FIG. FIG. 9 is a perspective view similar to FIG. 3, FIG. 10 is an exploded perspective view illustrating the method of sealing the container according to the present invention, and FIGS. , Partial longitudinal cross-sectional view showing the sealed state of the proposed container, No. 17
The figure is a cutaway perspective view of a package using the container of the present invention, and FIG. 18 is a perspective view showing the package of FIG. 17 in an unsealed state. The meanings of the main symbols in each figure are as follows: 1~
1″... Container of the present invention, 2... Flange portions from 1 to 1′,
3... Seal rib of 2, 4... Shooting part of 2, 5
...3, 3' coracoidal projection, 6... lid member, 7
... Item to be packaged, 8... Seal frame, 9... Heat plate.

Claims (1)

[Claims for Utility Model Registration] (1) A cup-shaped container in which an annular rib surrounding the upper edge of the main body made of thermoplastic plastic has a coronoid for opening the container, in which a part of the rib is adjacent to the annular rib. A cup-shaped container characterized by protruding portions that alternate in width and/or height with rib portions. (2) The container according to claim 1, wherein the contour line where adjacent wide ribs and narrow ribs overlap has a wavy shape. (3) The container according to claim 1, wherein the ridge line formed by adjacent high ribs and low ribs has a wavy shape as a whole.