JP5703047B2 - Aluminum can lid for beverages - Google Patents

Description

  The present invention relates to an aluminum can lid for beverages having a relatively high internal pressure, such as carbonated beverage cans and beer cans.

  2. Description of the Related Art Conventionally, a can filled with a soft drink or the like employs a structure in which the outer periphery of a can lid is double-rolled around an opening of a bottomed cylindrical can body (see Patent Document 1). Such a double tightening portion of the can has a flange portion formed in advance at the opening end portion of the can body, and a curl portion is formed in the outer peripheral portion of the can lid, and the can lid is formed on the flange portion of the can body. The curled part of the can lid is curled together on the outside, and the curled part of the can lid is rolled up so that the curled part is folded back from the outside of the flange part of the can body. It is formed by being pressed so as to be crushed from the outside, that is, by being deformed so that the upper ends of the can lid and the can body are rolled up.

  The sealing property of the container is maintained by filling the sealing compound between the can body and the can lid in the double winding portion. The sealing compound is applied in a predetermined thickness on the inner surface of the curled portion of the can lid before the tightening according to the shape of each part after the tightening, and is compressed by the tightening. It is desirable that the sealing compound be applied uniformly over the entire circumference of the can lid. Patent Document 2 discloses a method for inspecting a distribution state of a sealing compound.

JP 2004-331139 A JP 2008-76369 A

  In recent years, aluminum beverage cans have been reduced in cost by reducing the thickness of the can lid material. If the thickness of the can lid material is thin, the size of the double tightening portion can be reduced and the diameter of the can lid material can be reduced. Therefore, the thinning of the can lid material is effective in reducing the cost.

  However, if the thickness of the can lid material or the size of the double tightening portion is different, the appropriate application amount, thickness, application width, position, etc. of the sealing compound filling the gap between the can body and the can lid are also different. For this reason, in order to prevent the sealing performance from being impaired or the compound from protruding from the double tightening portion, an appropriate sealing compound should be provided according to the thickness of the can lid material and the size of the double tightening portion. Is required.

  This invention is made | formed in view of such a situation, and it aims at providing the aluminum can lid | cover for drinks which can ensure sealing performance without the protrusion of a sealing compound.

The present invention, the thickness is by molding the aluminum sheet material is less than 0.230mm or 0.210 mm, a cylindrical aluminum alloy can body double-seamed has been beverage that form a double-seaming unit An aluminum can lid for a disc, a chuck wall provided on the outer edge of the disc so as to continuously extend upward via a counter sink, and a radially outer side from the upper portion of the chuck wall 20 mg of a curled part that is folded back and then folded downward and extends radially inward to cover the opening end of the can body, and a sealing compound mainly composed of styrene-butadiene rubber on the inner surface of the curled part and a sealing compound layer formed by coating at a coverage of less than 35 mg, and the curled portion is deformed outwardly in the radial direction so as to be substantially parallel to the disc portion In the aspect, the sealing compound layer is formed with a predetermined coating width radially inward from a curl clearance having a width from an end edge of the curl portion of 0.5 mm to 1.5 mm, The application width is 3.0 mm or more and 5.0 mm or less in a straight line connecting the outer peripheral side end and the inner peripheral side end of the sealing compound layer in the longitudinal section of the can lid, and the double winding tightening In the state where the curled portion is put on the flange portion formed at the opening end portion of the can body, the flange portion and the curled portion are curled integrally on the outside, and the curled portion of the can lid is Formed by wrapping from the outside of the flange part of the can body while wrapping it so as to be crushed and pressing the entangled part further from the outside in the radial direction It is.

  According to this aluminum can lid for beverages, since a sealing compound layer is appropriately formed with respect to the plate thickness of the can lid, it can be reliably filled between the can body when wound on the can body, In addition, the sealing compound does not protrude from the double winding part. In particular, when the can lid is made of a thin plate material, the gap between the can body and the can lid is small and the double winding portion is small, so that the sealing compound tends to protrude, but a curl clearance is provided. Thus, the sealing compound can be accommodated inside the double tightening portion.

In this beverage aluminum can lid, wherein Ri coating amount der least 35mg or less 20mg of the sealing compound which forms a sealing compound layer, the thickness of the sealing compound layer is appropriate, while preventing extrusion of the sealing compound The sealability can be ensured more reliably.

  According to the aluminum can lid for beverages of the present invention, since the sealing compound can be filled between the can lid and the can body without protruding from the double winding portion, the aluminum can lid for beverages that can ensure sealing performance Provision becomes possible.

It is sectional drawing which shows the principal part of the aluminum can lid for drinks which concerns on this invention, and a can body. It is a half sectional view showing the aluminum can lid for drinks concerning the present invention. It is principal part sectional drawing which shows the aluminum can lid | cover for drinks of the state which deform | transformed the curl part. It is principal part sectional drawing which shows the aluminum can lid for drinks and a can body in the middle of winding. It is principal part sectional drawing which shows the aluminum can lid for drinks and a can body after winding-up.

  Hereinafter, an embodiment of an aluminum can lid for beverages according to the present invention will be described. An aluminum can lid for beverage (hereinafter referred to as “can lid”) 10 of the present embodiment has an outward flange at the upper end of a bottomed cylindrical body portion 21 by drawing and ironing (DI processing) an aluminum alloy plate material. The portion 22 is double-rolled to the opening of the can body 20 formed in a continuous shape (see FIG. 1).

  The can lid 10 is formed by press-molding an aluminum alloy lid material having a base plate thickness of 0.210 mm or more and 0.230 mm or less, and enters the inside of the can body 20 as shown in FIGS. 1 and 2. A disc portion 11 having a diameter smaller than that of the barrel portion 21 of the barrel 20, a chuck wall 13 provided so as to extend upward from the outer edge portion of the disc portion 11 via the counter sink 12, and a diameter from the upper end of the chuck wall 13. It has a curled portion 14 that extends outward in the direction and covers the open end of the can body 20, and a sealing compound layer 30 formed by applying a sealing compound to the inner surface of the curled portion 14. The sealing compound is an elastic sealing material mainly composed of, for example, styrene-butadiene rubber. The sealing compound layer 30 is formed with a uniform thickness over the entire circumference, for example, by spraying a liquid sealing compound toward the inner surface of the curled portion 14 while rotating the can lid 10.

  In the can lid 10, the curled portion 14 extends radially outward from the upper portion of the chuck wall 13, and then is folded downward to extend radially inward (that is, toward the can body 20). It is formed in a letter shape. As shown in FIG. 3, when the sealing compound layer 30 is in a measurement state in which the curled portion 14 is deformed radially outward so as to have a flange shape substantially parallel to the disc portion 11, the curled portion 14 is formed. The width w1 from the end edge portion is formed at a predetermined application width w2 radially inward from the curl clearance 31 having a width of 0.5 mm to 1.5 mm. The coating width w2 is a linear distance connecting the outer peripheral end 32 and the inner peripheral end 33 of the sealing compound layer 30 in the longitudinal section of the can lid 10 and is 3.0 mm or greater and 5.0 mm or less.

  When the can lid 10 and the can body 20 are double-tightened, as shown in FIG. 4, the end edge of the flange portion 22 of the can body 20 is tightened while biting into the sealing compound layer 30. In some cases, the compound may be moved toward the edge of the curled portion 14 as indicated by an arrow. In this case, if the sealing compound is applied to the entire inner surface of the curled portion 14, the sealing compound may protrude from the double winding portion. On the other hand, since the can lid 10 of the present invention is provided with the curl clearance 31 to which the sealing compound is not applied at the edge of the curled portion 14, there is an excess of the sealing compound at the edge of the curled portion 14. It is difficult to occur and it is difficult to protrude from the double winding part.

  As shown in FIG. 5, gaps C <b> 1 and C <b> 2 between the can lid 10 and the can body 20 are formed in the double winding tightening portion. As can be seen from this figure, the smaller the plate thickness of the can lid 10, the smaller the gap C2. In the double tightening portion, a sealing compound is provided between the inner surface of the curled portion 14 and the can body 20 (that is, the seaming panel 10a, the seaming wall 10b, the cover hook radius 10c, and the inside of the cover hook 10d and the gap C1). Since the space between the can lid 10 and the can body 20 is sealed by being filled in a compressed state, the absence of a sealing compound applied to the curl clearance 31 having a predetermined width w1 does not affect the sealing performance.

  If the sealing compound moves in the winding process as shown in FIG. 4, the sealing compound may protrude into the gap C2, as shown in FIG. However, in the can lid 10 according to the present invention, since the sealing compound is not applied in a predetermined range (curl clearance 31) between the gap C1 and the gap C2, the sealing compound is accommodated in the gap C2, and the double winding. It does not protrude from the fastening part.

  As described above, according to the can lid 10 according to the present invention, since the sealing compound layer 30 is appropriately formed with respect to the plate thickness of the can lid 10, the space between the can body 20 can be reliably sealed. In addition, the sealing compound does not protrude from the double winding part. In particular, when the can lid 10 is made of a thin plate material, the gap between the can body 20 and the can lid 10 is small and the double winding portion is small, so that the sealing compound tends to protrude, but a curl clearance 31 is provided. As a result, the sealing compound can be accommodated inside the double winding portion.

  Experiments were conducted to confirm the presence or absence of leakage of the sealing compound and the occurrence of leakage of the contents of the aluminum can lid for beverages with different curling clearance and coating width of the sealing compound. The protrusion of the sealing compound was confirmed by visual observation, and the content leakage was confirmed by a seam gap generation test. The results are shown in Table 1.

  The coating amount of the sealing compound was constant between 20 mg and 35 mg. Therefore, the larger the coating width, the thinner the sealing compound layer. The curl clearance and the coating width are average values measured at eight locations equally divided in the circumferential direction.

  The seam gap generation test is a test method disclosed in Japanese Patent Laid-Open No. 2001-305003. Briefly, the beverage can filled with the content liquid is inverted and supported from below with a tapered diameter-reduced portion that continues to the neck, a hole is made in the bottom of the beverage can, and approximately 0.5 MPa is compressed from the hole. Air is pressed into the can and held for 5 minutes in that pressurized state. Thereafter, a load of about 157 N (about 16 kgf) is repeatedly applied to the tightened portion in the axial direction at 3.3 Hz, and the occurrence of leakage from the tightened portion is visually confirmed. In each test, 10 cans were measured, and the application time of vibration and axial load for 5 minutes passed. No leak occurred even if 1 can leaked. It was judged.

  As a result of the experiment, when the curl clearance was 0 mm, there was no leakage of the contents, but the sealing compound protruded. On the other hand, when the curl clearance was increased to 1.6 mm, the sealing compound did not protrude but the contents leaked.

  When the curl clearance was 0.5 mm and 1.5 mm, the sealing compound protruded when the coating width was small and 2.0 mm. This is presumably because the application amount of the sealing compound was made constant, so that when the application width was small, the sealing compound layer was thickened and was easily pushed out by the flange edge of the can body during double winding. On the other hand, if the coating width was large and 5.5 mm, the contents leaked. This is considered to be because when the coating width is large, the sealing compound layer becomes thin, and the sealing compound is not sufficiently filled between the can lid and the can body.

  In addition, this invention is not limited to the thing of the structure of the said embodiment, In a detailed structure, it is possible to add a various change in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 10 Beverage aluminum can lid 10a Seaming panel 10b Seaming wall 10c Cover hook radius 10d Cover hook 11 Disk part 12 Countersink 13 Chuck wall 14 Curl part 20 Can body 21 Body part 22 Flange part 30 Sealing compound layer 31 Curl clearance 32 Outer peripheral end of the sealing compound layer 33 Inner peripheral end C1, C2 of the sealing compound layer Cavity w1 Width of curl clearance w2 Application width of the sealing compound layer

Claims (1)

Thickness is by molding the aluminum sheet material is less than 0.230mm or 0.210 mm, a cylindrical aluminum alloy can body double-seamed has been aluminum can lid for a beverage that form a double-seaming unit Because
A disk part,
A chuck wall provided on the outer edge of the disc portion so as to continuously extend upward through a counter sink;
A curl portion that extends radially outward from the upper portion of the chuck wall, then is folded downward and extends radially inward, covering the opening end of the can body; and
A sealing compound layer formed by applying a sealing compound having elasticity of styrene-butadiene rubber as a main material on the inner surface of the curled portion in an application amount of 20 mg to 35 mg ;
In a state where the curled portion is deformed radially outward so as to be substantially parallel to the disc portion,
The sealing compound layer is formed with a predetermined application width radially inward from a curl clearance having a width from an edge of the curl portion of 0.5 mm to 1.5 mm,
As for the coating width, a linear distance connecting the outer peripheral side end and the inner peripheral side end of the sealing compound layer in the longitudinal section of the can lid is 3.0 mm or more and 5.0 mm or less.
With
The double winding portion is configured such that the flange portion and the curled portion are integrally curled outwardly in a state where the curled portion is put on the flange portion formed at the opening end portion of the can body, and the can lid is The curled portion is wound by being folded while being folded from the outside of the flange portion of the can body, and the wound portion is further pressed to be crushed from the outside in the radial direction. An aluminum can lid for beverages.

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