JPH0829780B2 - Partial image open can lid with excellent openability - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a partial opening lid (hereinafter, simply referred to as an easy open can lid) capable of smoothly performing initial opening and tearing of an opening piece.

The present invention relates to a partial easy open can among them.

[Conventional technology]

The easy-open can lid allows the can lid to be opened by the pulling force of the fingertip without the need for tools such as canning. Utilizing this advantage, it is currently used in a wide range of applications such as food cans, carbonated beverage cans, beer cans, and the like.

In order to improve the openability of this easy open can lid,
Various proposals for can lids have been made so far. For example, JP-A-58-149251 proposes an easy-open can lid provided with a main score engraved on the can lid and an auxiliary score close to the main score.

Thus, by providing the auxiliary score, the can openability is improved to some extent.

[Problems to be solved by the invention]

The force required to open this easy open can lid is
It is mainly divided into the initial opening force at the start of opening, the force to tear the opening piece and the force to separate the opening piece from the can lid.
Then, in order to improve the can openability, it is necessary to reduce these forces first. In addition to this, when these forces are smoothed, it is possible to stably open the can with a constant force, and the highest openability is obtained. If the force required to tear the opening piece is large among these forces, the opening piece is separated with the large force applied. As a result, unexpected movements such as shocks and vibrations are transmitted to the entire easy-open can, causing the contents to spill.

Therefore, an object of the present invention is to facilitate opening of an easy-open can by reducing the force required for initial opening and tearing of the opening piece.

[Means for solving problems]

In order to achieve the object, the partial easy open can lid of the present invention is provided with a score so as to surround an opening piece provided with a pulling tab through a fixing portion, and a single or a plurality of pieces for reducing bending rigidity. A thin portion or a plurality of depressions are provided in the opening piece.

At this time, the can openability is further improved by setting the distance between the apex of the fixed portion of the pulling tab and the score of the apex of the opening piece to 0.4 mm or less.

〔Example〕

Hereinafter, the features of the present invention will be specifically described by way of examples with reference to the drawings.

FIG. 1 shows a partial easy open can lid of this embodiment.

A score 2 is engraved on the partial easy open can lid 1, and a portion surrounded by the score 2 becomes an opening piece 3. A protrusion is press-molded on a part of the opening piece 3, and after the hole portion of the pulling tab 4 is fitted into the protrusion, the protrusion is caulked to form the fixed portion 5 to which the pulling tab 4 is attached. are doing. When the pulling tab 4 thus provided is pulled and pulled, the apex 3a of the opening piece 3 on the fixed portion 5 side becomes the opening start point, and the opening piece 3 is sequentially torn from the lid main body along the tearing direction 6.

At this time, the auxiliary score 7 may be engraved along the score 2 on the main body of the can lid 1 having no opening. As the auxiliary score 7, various cross-sectional shapes such as V-shape, U-shape, and groove shape can be adopted.

In such an easy open can lid 1, the opening piece 3 is provided with a thin portion 8. As shown in FIG. 1, the thin portion 8 can be provided over the entire inside of the opening piece 3 with a suitable distance (for example, about 0.2 m) from the periphery of the opening piece 3. Alternatively, it is possible to divide the inside of the opening piece 3 into a plurality of areas and provide the thin portion 8 in each area. Further, the thin portion 8 may be provided from either the front surface or the back surface of the opening piece 3.

FIG. 2 shows an example in which a plurality of depressions 9 are provided instead of the thin portion 8. Further, the recess 9 is shown in FIG.
As shown in (d), it may be a recess formed from the upper portion, a recess formed from the lower portion, or a recess formed by making the plate uneven. The cross-sectional shape of the depression may be square, U-shaped, circular, trapezoidal, or the like. Further, other than those shown in FIG. 3, these recesses 9 may be those having various cross-sectional shapes that reduce the bending rigidity of the opening piece 3.

By providing the thin portion 8 or the recess 9, the bending rigidity of the opening piece 3 in the tearing direction 6 is reduced. That is, when the thickness of the plate material forming the opening piece 3 is locally reduced, the bending rigidity of that portion is reduced, and also when unevenness is provided, the bending rigidity is also locally reduced.
Therefore, when tearing the opening piece 3 along the tearing direction 6, the opening piece 3 is easily bent along the XX axis direction.

On the other hand, the thin portion 8 or the depression 9 facilitates the deformation of the opening piece 3 at the start of opening, and thereby concentrates the deformation at the start of opening on the score 2 around the fixing portion 5 from the apex 3a of the opening piece 3. . As a result, not only the opening force at the initial stage of opening is reduced, but also the opening piece 3 is easily torn along the score 2. Since the force required for this tearing is small, it is possible to prevent an excessive force from being applied when the opening piece 3 is separated from the lid body.

Further, the thin portion 8 or the depression 9 can be used as a display showing a brand name or contents.

When the opening piece 3 is provided with the plurality of depressions 9 shown in the second,
It is preferable that the distance l between the depressions 9 is 0.5 to 2 mm.
That is, when maintaining this mutual distance l within this range,
The bending rigidity is reduced by one depression 9, and the portion of the opening piece 3 and that by the other depression 9 become continuous, and the effect of reducing the tearing force is ensured. When the mutual distance l exceeds 2 mm, the tearing force changes along the tearing direction 6, and the tearing cannot be performed with a stable force.
Further, when the mutual distance l is less than 0.5 mm, the waist of the opening piece 3 becomes weaker than necessary, and the opening piece 3 may be partially torn in some cases.

FIG. 4 shows an example in which the rigidity of the opening piece 3 is lowered along the tearing direction 6 in this manner, and a means for lowering the force required at the start of can opening is added. FIG. 5 is a sectional view around the opening piece 5 in that example.

In this example, the apex 5a of the fixed portion 5 and the apex of the opening piece 3
The distance a to the 3a is 0.4 mm or less, preferably 0.3 mm or less.

FIG. 6 shows the effect of this distance a on the initial can opening force. In this example, a tin plate having a plate thickness of 0.25 mm and a temper degree of T-4 was used. As is clear from this figure, the initial can opening force begins to decrease at the distance a = 0.4 mm, and tends to decrease almost constant at 0.3 mm or less. The sharp decrease in the can opening force is considered to be because the influence of the highly rigid fixing portion 5 is transmitted to the apex 3a of the opening piece, and the stress concentration becomes more localized.

Therefore, the opening of the can can be started with a small force, and in combination with the effect of the thin portion 8 or the depression 9 described above, the steps from the opening of the can to the tearing can be smoothly performed. Furthermore, when the opening piece 3 is separated from the lid body, it is also prevented that an excessive force is applied to the opening piece 3, so that the vibration, impact, etc. applied to the body of the easy open can by the reaction thereof are small. .

Then, as a test material, the plate thickness is 0.23 mm and the temper degree is T-4.
The difference in the effect given by the shape of the opening piece when the partial easy open can lid is manufactured by using the tin plate material will be specifically described. As the shape of the opening piece, three types shown in FIG. 7 were adopted. FIG. 1A shows a conventional opening piece having no thin portion or dent, and an auxiliary score 7 is provided on the non-opening side of the can lid main body along the score 2.
FIG. 3B shows an opening piece provided with the recess 9 according to the present invention, and the mutual interval l of the recesses 9 is about 1 mm. The same figure (c)
Is an opening piece provided with the thin portion 8 according to the present invention.

The initial opening force (pop value: F _P ) and tearing force (tier value: F _T ) when these partial easy open can lids were opened were measured. The results are shown in Table 1. In Table 1, the test pieces Nos. 1 to 3 have a distance a from the apex 5a of the fixing portion 5 to the apex 3a of the opening piece 3 of 0.4 mm, and the test piece Nos.
4 is the distance a in the opening piece of FIG. 7 (c) set to 0.2 mm. As can be seen from this table, conventional test pieces
In the case of the present invention in which the bending rigidity of the opening piece is reduced by the thin portion 8 or the depression 9 as compared with No. 1, it can be seen that both the hop value and the tear value are reduced. Also, set the distance a to 0.
It can be seen that the pop value is even smaller for the test piece No. 4 which is reduced to 2 mm.

A tin material or an aluminum plate is usually used as a material for the can lid. However, in the present invention, it is not necessary to limit the material used for the can lid, and the following materials other than this can be used.

(1) Non-ferrous metal material typified by iron and iron alloys or aluminum and aluminum alloys (2) Metal material obtained by subjecting the metal material of (1) above to surface treatment such as plating or painting (3) The above (1) and And / or (2) a composite metal material in which an organic material such as a resin is joined to the metal material in a layered manner (4) A composite metal material in which the different metal materials of (1) and / or (2) are connected in a layered manner, When the composite material as described in (3) and (4) above is used, a thin portion shown in FIGS. 1 to 3 is formed by forming a space portion in one layer and laminating another layer on the space portion. It is also possible to form 8 or depressions 9.

〔The invention's effect〕

As explained above, in the partial easy open can lid of the present invention, since the bending rigidity is reduced by providing the opening piece with the thin portion or the recess,
The opening piece can be torn from the lid body with a small force.
Therefore, the openability of the partial easy open can lid is excellent.

[Brief description of drawings]

FIG. 1 is a plan view showing a partial easy open can lid having an opening piece provided with a thin portion as one embodiment of the present invention, and FIG. 2 shows another embodiment having a depression, and FIG. FIG. 3 is a cross-sectional view showing several examples of depressions provided in the opening piece shown in FIG. Further, FIG. 4 shows an example in which means for lowering the initial can opening force is added, and FIG. 5 shows the distance a shown in FIG.
It is a figure explaining. Further, FIG. 6 shows the influence of the distance between the apex of the fixed portion and the apex of the opening piece on the initial can opening force, and FIG. 7 shows a case where the effect is specifically described in one embodiment of the present invention. It is a figure which shows an opening piece.

Continuation of the front page (56) Bibliography Sho 53-33550 (JP, U) Rib 58-109922 (JP, U) Rib 54-157 (JP, U)

Claims (2)

[Claims] 1. A score is provided so as to surround an opening piece provided with a pulling tab through a fixing portion, and one or a plurality of thin-walled portions or a plurality of depressions which reduce bending rigidity are provided in the opening piece. Partial easy open can lid with excellent openability characterized by 2. The excellent openability according to claim 1, wherein the distance between the apex of the fixed portion of the pulling tab and the score of the apex of the opening piece is 0.4 mm or less. Partial easy open can lid.