CN118877360A - A basic cover for an easy-open can lid and an easy-open can lid - Google Patents

Abstract

The invention provides a basic cover of an easy-open can cover and the easy-open can cover, and relates to the technical field of packaging containers. The cross section of the basic cover of the can cover of the easy-to-open can sequentially comprises a seaming area, a transition area, a concave section, an arc wall section and a central panel from the periphery to the center, wherein the concave section sequentially comprises a first arc section, a first straight line section and a second arc section from the periphery to the center, the first arc section is tangent with the transition area, the first arc section is tangent with the first straight line section, and the first straight line section is tangent with the second arc section; the radius of the first arc section is set to be a, and a is more than or equal to 0.08mm and less than or equal to 0.2mm; the radius of the second arc section is set to be b, and b is more than or equal to 0.15mm and less than or equal to 0.4mm; the arc wall section sequentially comprises a second straight line section and a third arc section from the periphery to the center, wherein the second straight line section is tangent with the second arc section, and the third arc section is tangent with the center panel; the radius of the third arc section is c, and c is more than or equal to 1.5mm and less than or equal to 4mm. The basic cover has good consistency of yield stress, and can effectively reduce the breakage rate under positive pressure.

Description

A basic cover for an easy-open can lid and an easy-open can lid

Technical Field

The invention belongs to the technical field of packaging containers and relates to a basic cover for an easy-open can cover and an easy-open can cover.

Background Art

Easy-open cans, such as two-piece cans and three-piece cans, have become packaging containers that can be seen everywhere in people’s daily lives. Easy-open cans usually contain liquids with a certain pressure, such as beer, beverages, etc. The pressure inside the can will increase with the rise in temperature and shaking during transportation. As the thickness of easy-open cans becomes thinner and thinner, such as the thickness of the can cover as low as 0.208mm, higher requirements are placed on the pressure of the can cover to achieve lower pressure breakage and safety. For example, under the action of the pressure inside the can, when the internal pressure exceeds the yield strength of the material, the can cover is prone to bulging, deformation, and even damage. In addition to replacing the original stainless steel material with an aluminum alloy material with higher strength and lower density, a number of prior arts have also publicly reported improvements to the can cover structure to achieve higher pressure resistance. For example, Chinese invention patent CN108438434A discloses a pressure-resistant basic cover, which adds a sixth arc segment R6 and a second straight line segment L2 to the countersunk section, designs reasonable sizes of the fifth arc segment R5 and the sixth arc segment R6, and the center position relationship of the fourth arc segment R4 and the fifth arc segment R5, and other technical features to reduce the probability of rupture during pressure failure to 0.05% to 2.5%.

The inventor believes that the existing easy-open can lid structure can be further optimized.

Summary of the invention

Since the thickness of the easy-open can lid is already very thin, it cannot be further thinned. Therefore, the structure of the can lid must be further designed and optimized. After a lot of research and development analysis and testing, the inventor found that maintaining the consistency of the yield stress of the can lid can improve the pressure resistance of the can lid and reduce the breakage rate when the pressure increases. Based on this, the present invention provides a basic cover of an easy-open can lid and an easy-open can lid.

The technical solution of the present invention is as follows:

A basic cover for an easy-open can lid, wherein the cross section of the basic cover is composed of a rolling sealing area, a transition area, a concave section, an arc wall section and a central panel from the periphery to the center, wherein the concave section is composed of a first arc section, a first straight section and a second arc section from the periphery to the center, wherein the first arc section is tangent to the transition area, the first arc section is tangent to the first straight section, and the first straight section is tangent to the second arc section;

The radius of the first arc segment is set to a, 0.08 mm ≤ a ≤ 0.2 mm;

The radius of the second arc segment is set to b, 0.15 mm ≤ b ≤ 0.4 mm;

The arc wall segment is a second straight line segment and a third arc segment that are tangent to each other from the periphery to the center, the second straight line segment is tangent to the second arc segment, and the third arc segment is tangent to the center panel;

The radius of the third arc segment is set to c, 1.5mm≤c≤4mm.

Preferably, the transition zone comprises a third straight line segment, and the third straight line segment is tangent to the first circular arc segment.

Preferably, the angle A1 between the first straight line segment and the horizontal direction is 2-15°.

More preferably, the angle A1 is 3-10°.

Preferably, the value of a satisfies: 0.1 mm≤a≤0.17 mm.

Preferably, the value of b satisfies: 0.18 mm ≤ b ≤ 0.35 mm.

Preferably, the angle A2 between the second straight line segment and the vertical direction is 10-35°.

More preferably, the angle A2 is 13-28°.

Preferably, the center of the third arc segment is not lower than the lowest point of the concave portion of the concave segment in the horizontal direction.

An easy-open can cover comprises the basic cover of the easy-open can cover according to any one of the above embodiments.

The beneficial effects of the present invention are as follows: the present invention proposes a tank cover structure that can improve the consistency of yield stress by analyzing the stress distribution of the tank cover under internal positive pressure and the common pressure rupture modes of the tank cover. By arranging two left and right arcs with different arc radii in the concave section and arranging an arc section with a longer arc radius in the arc wall section, the yield stress of different parts of the basic cover can be made more consistent, which is more conducive to resisting the stress effect of the internal positive pressure, reducing the breakage rate under high pressure, and the bulging undamaged rate is also low.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial schematic cross-sectional view of a basic cover of Example 1. FIG.

FIG. 2 is an enlarged schematic diagram of the curved frame portion in Example 1.

FIG. 3 is a partial schematic cross-sectional view of the basic cover of Example 1. FIG.

DETAILED DESCRIPTION

The technical solution of the present invention is further illustrated and described below through specific implementation methods.

The term "horizontal direction" in the present invention is interpreted as follows: a direction along the basic cover cross section and perpendicular to the middle axis of the can cover.

The term "vertical direction" in the present invention is explained as follows: a direction parallel to the middle axis of the can cover. Upward, the direction in which the can cover surface is away from the can bottom.

In order to improve the compression resistance of the easy-open can lid, from the dimension of improving the uniformity of the yield stress of each part of the lid, on the one hand, the present invention provides a basic lid of an easy-open can lid, the cross section of the basic lid from the periphery to the center, in order, comprises a roll-sealing area (1), a transition area (2), an inner concave section (3), an arc wall section (4) and a central panel (5). The basic lid of the present invention is improved on the basis of the basic lid of the prior art, and the structures of the roll-sealing area (1), the transition area (2) and the central panel (5) are not particularly limited, and reference may be made to the records of the prior art CN108438434A, CN106672390A, CN105408216A, etc.

With respect to the concave section (3), the design of the present invention is as follows: the concave section (3) is composed of a first arc section (R1), a first straight section (L1) and a second arc section (R2) from the periphery to the center, the first arc section (R1) and the transition zone (2) are tangent to each other, the first arc section (R1) and the first straight section (L1) are tangent to each other, and the first straight section (L1) and the second arc section (R2) are tangent to each other;

The radius of the first arc segment (R1) is set to a, 0.08 mm ≤ a ≤ 0.2 mm;

The radius of the second arc segment (R2) is set to b, 0.15 mm ≤ b ≤ 0.4 mm;

The structure of the above-mentioned concave section (3) is composed of a first arc section (R1) and a second arc section (R2), and the first straight line section (L1) is used to connect them in the middle. The inventors found that the damage of the easy-open can lid under positive pressure mainly occurs in the transition section and the arc wall section, especially the transition section, which means that the yield stress of the transition section is relatively low among all parts of the entire can lid. In the present invention, through the structural design of the above-mentioned concave section (3), while the yield stress of the transition zone (2) is increased, the yield stress of the concave section (3) will not be reduced, and the consistency of the yield stress of each part of the basic cover is maintained, which can effectively reduce the high-pressure damage rate of the can lid. In the present invention, further, the radius of the first arc section (R1) is smaller than the radius of the second arc section (R2). For example, the value of a can be any value among 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.20mm, etc., or any value therebetween, without any particular limitation. For example, the value of b can be any value among 0.15mm, 0.17mm, 0.20mm, 0.21mm, 0.22mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.30mm, 0.32mm, 0.34mm, 0.35mm, 0.36mm, 0.38mm, 0.40mm, etc., or any value therebetween, without any particular limitation.

With respect to the arc wall segment (4), the design of the present invention is as follows: the arc wall segment (4) is sequentially tangent to a second straight line segment (L2) and a third arc segment (R3) from the periphery to the center, the second straight line segment (L2) is tangent to the second arc segment (R2), and the third arc segment (R3) is tangent to the center panel;

The radius of the third arc segment (R3) is set to c, 1.5mm≤c≤4mm. For example, the value of c can be any value of 1.5mm, 1.7mm, 1.8mm, 2.0mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.2mm, 3.3mm, 3.5mm, 3.6mm, 3.8mm, 4.0mm, etc. or any value in between, without special restrictions. Further, the value of c can be 2-3mm.

The structural design of the concave section (3) and the arc wall section (4) forms a good integration with the transition zone (2), and while increasing the yield stress of the transition zone (2), the yield stress of the arc wall section (4) will not be reduced, further effectively reducing the high-pressure damage rate of the tank cover.

In the present invention, the transition zone (2) comprises a third straight line segment (L3), and the third straight line segment (L3) is tangent to the first arc segment (R1). By adopting the above technical solution, the continuity and smoothness of the connection between the transition zone (2) and the concave segment (3) can be improved, thereby avoiding reducing the yield stress.

In the present invention, the angle A1 between the first straight line segment (L1) and the horizontal direction is 2-15°. The first straight line segment (L1) and the horizontal direction form a certain angle A1, that is, the second arc segment (R2) deviates upward relative to the first arc segment (R1). For example, the angle A1 can be any value of 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, etc. or any value in between, without special restrictions. Further, the angle A1 is 3-10°.

In the present invention, the value of a satisfies: 0.1 mm ≤ a ≤ 0.17 mm. For example, the value of a can be any value among 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, etc., or any value therebetween, without any particular limitation.

In the present invention, the value of b satisfies: 0.18 mm ≤ b ≤ 0.35 mm. For example, the value of b can be any value among 0.18 mm, 0.20 mm, 0.21 mm, 0.22 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.30 mm, 0.32 mm, 0.34 mm, 0.35 mm, etc., or any value therebetween, without any particular limitation.

In the present invention, the angle A2 between the second straight line segment (L2) and the vertical direction is 10-35°. For example, the angle A2 can be any value of 10°, 12°, 13°, 15°, 16°, 18°, 19°, 20°, 22°, 23°, 24°, 25°, 26°, 28°, 29°, 30°, 32°, 33°, 34°, 35°, etc. or any value therebetween, without special limitation. Furthermore, the angle A2 is 13-28°.

Furthermore, in the present invention, the center of the third arc segment (R3) is not lower than the lowest point of the concave portion of the concave segment (3) in the horizontal direction.

On the other hand, the present invention further provides an easy-open can cover, comprising the easy-open can cover basic cover described in any one of the above embodiments. The easy-open can of the present invention has a higher yield stress, which can reduce the breakage rate under positive pressure.

The technical solution of the present invention is further described and illustrated according to various embodiments below.

Example 1

Referring to FIG. 1 , the cross section of the basic cover of the easy-open can lid includes, from the periphery to the center, a roll-sealing area 1, a transition area 2, a concave section 3, an arc wall section 4, and a center panel 5. The structures of the roll-sealing area 1, the transition area 2, and the center panel 5 can refer to the records of the prior art CN106672390A. The roll-sealing area 1, the transition area 2, and the center panel 5 in the present invention correspond to the can sealing area, the countersunk section, and the center cover surface in the prior art CN106672390A, respectively, that is, in the basic cover of the present invention, the roll-sealing area includes, from the periphery to the center, a fourth arc section R4 (corresponding to the first arc section in CN106672390A, not shown in the drawings of this embodiment), a fifth arc section R5 (corresponding to the second arc section in CN106672390A, not shown in the drawings of this embodiment), and a sixth arc section R6 (corresponding to the second arc section in CN106672390A, not shown in the drawings of this embodiment). The third arc segment in CN106672390A, not shown in the drawings of this embodiment), R5 is tangent to R4 and R6 respectively; the transition zone is connected and tangent to the fourth straight line segment L4 (corresponding to the first straight line segment in CN106672390A, not shown in the drawings of this embodiment), the seventh arc segment R7 (corresponding to the fourth arc segment in CN106672390A, not shown in the drawings of this embodiment), and the eighth arc segment R8 (corresponding to the fifth arc segment in CN106672390A, not shown in the drawings of this embodiment), the other end of L4 is connected and tangent to R6, the radius of R8 is 3.5mm, and the radius of R7 is 1.5mm. The angle between the tangent line of L4 and R6 and the vertical direction is 12°.

The concave section (3) is composed of a first arc segment R1, a first straight segment L1 and a second arc segment R2 from the periphery to the center. The first arc segment R1 is tangent to the transition zone 2, the first arc segment R1 is tangent to the first straight segment L1, and the first straight segment L1 is tangent to the second arc segment R2. The radius a of the first arc segment R1 is 0.12 mm; the radius b of the second arc segment R2 is 0.23 mm. The transition zone 2 includes a third straight segment L3, one end of the third straight segment L3 is tangent to the first arc segment R1, and the other end of the third straight segment L3 is tangent to the eighth arc segment R8.

The arc wall segment 4 is composed of a second straight line segment L2 and a third arc segment R3 which are tangent to each other from the periphery to the center. The second straight line segment L2 is tangent to the second arc segment R2, and the third arc segment R3 is tangent to the center panel. The radius c of the third arc segment R3 is 2 mm. The center of the third arc segment R3 is not lower than the lowest point of the concave portion of the concave segment 3 in the horizontal direction.

2 , the angle A1 between the first straight line segment L1 and the horizontal direction is 6°, and the angle A2 between the second straight line segment L2 and the vertical direction is 23°.

The can cover is made of 5182 aluminum alloy with a thickness of 0.208 mm. It is prepared into a two-piece can. The can body and the bottom of the can are made of 3004 aluminum alloy with a thickness of 0.22 mm. The can cover structure is respectively the structure of Example 1 in the prior art CN106672390A (recorded as the prior art) and the structural design of the above-mentioned Example 1 (recorded as the present invention), wherein the structures of the rolling sealing area, the transition area and the center panel are the same. The above-mentioned can cover is made into a two-piece can, and the two-piece can is placed in the easy-open cover pressure tester CanNeed-AEBT-1000 for testing. Testing conditions: 25°C, 55% humidity, pressurized to 0.7MPa. The breakage rate and bulging non-breakage rate of 1,000 two-piece cans are counted. The breakage rate of the can cover of the prior art is 75.4%, and the remaining can covers are bulging and not broken; the can cover breakage rate of the present invention is 1.47%, and the can cover bulging non-breakage rate is 20.1%. The above data show that the basic cover of this embodiment has a higher yield stress.

Example 2

Referring to FIG3, the basic cover structure of this embodiment is basically the same as that of embodiment 1, except that the radius c of the third arc segment (R3) in FIG3 is 2.8 mm. According to the above-mentioned test scheme for the breakage rate, in this embodiment, the breakage rate of the two-piece can cover is 1.82%, and the can cover bulge unbroken rate is 25.8%, indicating that the basic cover of this embodiment has a higher yield stress.

As described above, the basic principles, main features and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited by the above embodiments, which are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the scope of the present invention and the content of the specification should still be within the scope of the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents.

Claims (10)

1. A basic cover for an easy-open can lid, wherein the cross section of the basic cover comprises, from the periphery to the center, a rolling sealing area (1), a transition area (2), a concave section (3), an arc wall section (4) and a center panel (5), characterized in that the concave section (3) comprises, from the periphery to the center, a first arc section (R1), a first straight section (L1) and a second arc section (R2), the first arc section (R1) and the transition area (2) are tangent to each other, the first arc section (R1) and the first straight section (L1) are tangent to each other, and the first straight section (L1) and the second arc section (R2) are tangent to each other; The radius of the first arc segment (R1) is set to a, 0.08 mm ≤ a ≤ 0.2 mm; The radius of the second arc segment (R2) is set to b, 0.15 mm ≤ b ≤ 0.4 mm; The arc wall segment (4) comprises, from the periphery to the center, a second straight line segment (L2) and a third arc segment (R3) which are tangent to each other, the second straight line segment (L2) being tangent to the second arc segment (R2), and the third arc segment (R3) being tangent to the center panel (5); The radius of the third arc segment (R3) is set to c, 1.5mm≤c≤4mm. 2. The basic cover of the easy-open can lid according to claim 1, characterized in that the transition zone (2) comprises a third straight line segment (L3), and the third straight line segment (L3) is tangent to the first circular arc segment (R1). 3. The basic cover of the easy-open can lid according to claim 1, characterized in that the angle A1 between the first straight line segment (L1) and the horizontal direction is 2-15°. 4. The basic cover of the easy-open can lid according to claim 3, characterized in that the angle A1 is 3-10°. 5 . The basic cover of the easy-open can lid according to claim 1 , wherein the value of a satisfies: 0.1 mm ≤ a ≤ 0.17 mm. 6. The basic cover of the easy-open can lid according to claim 1, characterized in that the value of b satisfies: 0.18 mm ≤ b ≤ 0.35 mm. 7. The basic cover of the easy-open can lid according to claim 1, characterized in that the angle A2 between the second straight line segment (L2) and the vertical direction is 10-35°. 8. The basic cover of the easy-open can lid according to claim 7, characterized in that the angle A2 is 13-28°. 9. The basic cover of the easy-open can lid according to claim 1, characterized in that the center of the third arc segment (R3) is not lower than the lowest point of the concave portion of the concave segment (3) in the horizontal direction. 10. An easy-open can cover, characterized by comprising the easy-open can cover basic cover according to any one of claims 1 to 9.