JPS6382944A - Vessel made of metal - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to metal containers, and particularly to metal containers such as metal cans filled with beer, soft drinks, etc. and sealed.

(Prior Art) Metal cans commonly used today are sealed by joining a can lid to a can body filled with contents such as beer or soft drinks by so-called "double seaming." Double seaming involves wrapping the curl of the can lid, whose outer periphery is bent into a predetermined shape, into a flange formed at the end of the can body from the outside, and then crimping the gap from the outside. In this method, the can body and can lid are joined together, and the can container is kept sealed by interposing a backing made of a rubber-like material (sealing compound) applied to the inside of the curled portion of the can lid. In other words, seaming is usually performed in two steps.In the first step, the can lid is curled by a first seaming roll, and the flange of the can body is fitted and rolled up, and in the second step, the second seaming roll is used to curl the can lid. The parts are crimped together and a sealing compound is filled into the void inside the crimped part to maintain airtightness.

Next, a seaming process that is a conventional method for manufacturing metal cans will be described with reference to FIGS. 9 to 11.

First, as shown in FIG. 9-(a), the can lid 22 is attached to the can body 21.
The can body 21 is placed on the can body 21, the lid plate 23 is raised, and the seaming chuck 24 is fitted inside the can lid 22 as shown in FIG. 9(b). The state at this time is shown in FIG. 10-(a), in which the curled portion 22c of the can lid 22 is placed on the flange portion 21f of the arc-shaped can body 21,
A seaming chuck 24 is fitted onto the inner peripheral surface of the can lid 22.

Next, as shown in FIG. 9-(c), the seaming chuck 24
While rotating the can body 21 and the can M22 held by the lifter plate 23, the first seaming roll 25 is attached to the can! 22
Press it against the curled portion 22C. The state at this time is m1
As shown in the diagram O-(b), the first seam is formed along the shape of the roll group 25a of the first seam roll 25. During this first tightening, a predetermined pushing force is applied to the lifter plate 23 by the lifter lid, a predetermined pressing force in the vertical direction is applied to the can body 21 and the can lid 22, and the can body flange 21
As f bends downward, the first seaming roll group 25a
The can lid curl 22c is rolled upward along the can lid curl 22c.

Then, the first seaming roll 25 moves away, and then the second seaming roll 26 approaches and crushes the first seaming to form a second seaming. The state at this time is shown in FIG. 1O-(c), and the second seam is formed along the shape of the roll group 26a of the second seam roll 26. Even during the closing of this second volume,
A predetermined pressing force is applied between the seaming chuck 24, the can body 21, and the can lid 22.

FIG. 11 shows the above 1. The sectional view of the seaming part of the metal can formed through the second seaming process is shown. In the figure, code 2
3 is a sealing compound.

(The problem that the invention attempts to solve) However, the main parts related to the formation of seaming can be simplified as the shape and size of the space formed by the lip of the chuck and the group of rolls, and the pushing force from below. be able to. Therefore, the major prerequisites for obtaining good seaming are the following conditions for the can seamer (sealing machine): ■ Appropriate lip shape and position adjustment of the seaming chuck ■ First. Appropriate group shape and position adjustment of the second seaming roll ■Appropriate pushing force of the lifter is required.

On the other hand, the conditions for metal cans are: - Thickness of the can body that can withstand the pressure applied to the can body - Regular dimensions of the can body and can lid - Curling of the can lid, proper formation and fit of the can body flange - Appropriate sealing compound application conditions are required. In other words, when joining the can body and can lid using a seamer, a predetermined vertical load (approximately 100 kg) is applied to the can body.
Because of this, the can body must have a wall thickness that can withstand the load, which poses a problem that prevents thinning of the music body. Further, as mentioned above, the can bodies and can lids of metal cans require high shape and dimensional accuracy, and in particular, there is a problem in that the can lid curl and the can body flange are required to be properly formed. On the other hand, the seamer side also requires various conditions, especially the shape and dimensional accuracy of the seaming chuck and seaming roll, which are the component parts of the seamer. There are problems in that the rolls must be aligned with high precision, and the seamer mechanism is complex and requires precise adjustment.

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to reduce the thickness of the can body of metal cans and to reduce the overlapping area of the can lid and can body required for joining, thereby reducing the amount of material used. In addition, the can body and can lid that constitute a metal can do not require high shape and dimensional accuracy, and the structure and adjustment method of the device used to sealingly join the can body and can lid are simplified. The objective is to provide a metal container that can

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a metal container comprising a can body made of a bottomed cylindrical body and a can lid for sealing the mouth of the can body. , an outer peripheral surface for joining is provided at the mouth of the can body, the outer diameter of which gradually decreases upward;
The above-mentioned can lid is provided with an inner circumferential surface for joining which has a shape corresponding to the above-mentioned outer circumferential surface for joining so as to closely fit, and after the can body is filled with contents, the outer peripheral surface for joining and the inner peripheral surface for joining are formed. and are adhesively sealed with a thermoplastic adhesive.

(Function) The present invention uses the above-mentioned means to fit the tapered outer circumferential surface of the can body and the tapered inner circumferential surface of the can lid into close contact with each other by interposing an adhesive between the two, and then A predetermined pressure is applied between the body and the can lid, and the two can be adhesively sealed by heating.

(Example) Hereinafter, an example of a metal container according to the present invention will be described with reference to FIGS. 1 to 6.

FIG. 1 is a sectional view of a metal can 1 constituting a metal container, and the metal can is constructed by joining a can body 2 and a can lid 3 with a thermoplastic adhesive 4.

The can body 2 is a cylindrical body with a bottom, and the upper part of the can body 2 is formed at a predetermined angle θ (preferably θ is within the range of 20″ to 60°) on the inside of the cylindrical body, as shown in FIG. The outer peripheral surface 2a for joining is bent at an angle by neck-in processing.The outer diameter of this outer peripheral surface 2a for joining gradually decreases toward the upper end, but the slope is not necessarily straight. It doesn't have to be the same.

On the other hand, the can lid 3 has an inner circumferential surface 3a for joining that is shaped to be closely fitted to the outer circumferential surface 2a for joining, and the inner peripheral surface for joining gradually becomes smaller toward the lower end. The inner diameter is larger. The outer periphery of the tip of the can lid 3 is rounded to prevent danger.

Next, the process of sealing the can body 2 and the can lid 3 will be described with reference to FIGS. 3 to 5.

First, as shown in FIGS. 3 and 4, adhesive 4 is applied to either the outer peripheral surface 2a for joining on the can body side or the inner peripheral surface 3a for joining on the can lid side. Also, apply silicone compound 5 to the can lid 3. When the can body 2 filled with the contents 6 is placed on the lifter 7 as shown in FIG. 5, the can lid 3 is placed over the can body 2.

Next, the lifter 7 rises, and the chuck 8 compresses the can body 2 and can lid 3 (the crimping load may be 40 dan or less).
. Then, using a high frequency seeker 9, the entire circumference of the joint is heated to melt the adhesive 4, and the can body 2 and the can lid 3 are adhesively sealed. The electrode portion of the high-frequency seek 9 used at this time has a structure that allows cooling water to flow therethrough, so that it can be cooled immediately after the heating of the joint portion is completed. After this cooling process, the lifter 7 is lowered and the metal can 1 is discharged.

FIG. 6 is an explanatory diagram showing an automatic sealing process, in which an insulator 11 such as Bakelite is attached to a turret 10 made of aluminum, and a terminal 12 of a high frequency generator is provided above the turret 10. When the metal can to be joined comes to the terminal 12 as the metal can rotates,
The induced current heats the entire circumference of the joint.

Therefore, while the outer peripheral surface 2a for joining of the can body 2 of this embodiment forms a tapered portion with a gradually smaller diameter toward the upper end,
The joining inner circumferential surface 3a of the can lid 3 forms a tapered portion that gradually becomes larger in diameter toward the lower end, and has excellent centering properties when the can lid 3 is placed over the can body 2, and the tapered portions fit together easily. It has excellent adhesion.

In the embodiment shown in FIG. 1, a sealing compound was interposed between the can body and the can lid. The sealing effect may be enhanced by applying an adhesive 4 between the upper end of the holder and the upper end of the holder.

Furthermore, as shown in FIG. 8, it is also possible to provide an outwardly curled portion 2c at the upper end of the can body 2 to more actively prevent the end surface of the can body from coming into contact with the contents.

(Experimental Results) In order to examine the practicality of the metal containers made in this way, the leakage was investigated by pressure resistance and drop tests, and the results are shown in Table 1 below. The internal pressure of canned products such as beer and carbonated drinks is 2 to 3 kg under normal storage and consumption conditions.
/cd, and even under slightly bad conditions it is 4 to 5 kg/cJ, and the pressure resistance of a metal can with conventional double seaming is 7.5 k
The maximum standard value is g/c-. According to Table 1, the instantaneous pressure resistance of this container is 8 kg/cd or more, and large deformation (buckling) occurs before the adhesive part breaks.

Therefore, it can be said that this container has the same sealing performance as double seaming, which is the conventional sealing method for metal cans.

In addition, Table 1 shows the results of manufacturing a can product by filling the container with 4 gas voluminous carbonated beverage and sealing it, and examining the sustained pressure resistance and drop impact strength at 40° C. for 2 hours. No leakage occurred in either case, and it can be said that this container has practical performance in these respects as well.

Table 1 (Effects of the Invention) As is clear from the description of the embodiments, according to the present invention, since the can body and the can lid are adhesively sealed with an adhesive, the can body and the can lid are sealed together. There is no need to apply an excessive vertical load to the can body during joining, and the can body can be made thinner. Furthermore, depending on the selection of adhesive, it is possible to reduce the overlapping area between the can lid and the can body required for joining the can lid and the can body. Moreover, since the can body and the can lid do not require high shape accuracy and dimensional accuracy, it is possible to reduce the manufacturing cost of these container components.

Further, according to the present invention, there is no need to seal the can body and the can lid by seaming as in the conventional method, so the structure and adjustment method of the device used for sealing can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the metal container according to the present invention, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, and FIGS. 3 to 6 are seaming diagrams of the embodiment shown in FIG. Explanatory diagram of the process, No. 7
The figure is a cross-sectional view of another embodiment of the present invention, FIG. 8 is a cross-sectional view of still another embodiment of the present invention, and FIGS. 9 and 10 are explanatory diagrams showing the seaming process of a conventional metal container. FIG. 11 is a sectional view of a conventional metal container. 1... Metal can, 2... Can body, 3... Can lid, 4...
・Adhesive, 5...Sealing compound. Applicant's agent Sato -Yuusou 2 Figure 乎υ (o) (b)
(c) Ro-O diagram

Claims (1)

[Scope of Claims] 1. In a metal container comprising a can body consisting of a bottomed cylindrical body and a can lid that seals the mouth of the can body, the mouth of the can body gradually increases upwardly. An outer peripheral surface for joining with a reduced outer diameter is provided, an inner peripheral surface for joining is provided on the can lid with a shape corresponding to the shape so as to tightly fit into the outer peripheral surface for joining, and the can body is filled with contents. After that, the outer peripheral surface for joining and the inner peripheral surface for joining are adhesively sealed with a thermoplastic adhesive. 2. The metal container according to claim 1, wherein the angle θ of the joint surface between the can body and the can lid is within a range of 20° to 60° with respect to the vertical direction.