JP2538950Y2 - Metal lid for cans - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal lid for a can applied to dry pack products such as tea leaves, nuts, coffee, tobacco, potato chips, milk powder and the like.

[0002]

2. Description of the Related Art Dry pack products such as tea leaves, nuts, coffee, tobacco, potato chips, and milk powder contain the contents for the purpose of preventing oxidative deterioration of the contents and corrosion of the inner surface of the can. After that, deaeration is performed by a vacuum / gas replacement method, a vacuum deaeration method, a gas blowing method or the like, and then the lid is fixed by winding.

Conventionally, this kind of metal lid has a concave portion fitted into the opening of the can body, a flange is provided continuously with the peripheral wall of the concave portion, and a curl is provided continuously with the tip of the flange. A sealing compound is applied to the back surface of the flange, and after sealing, a sealing compound is used to ensure the tightness of the tightened portion by the action of the sealing compound.

In the case of such a metal lid, for example,
Vacuum degassing and inert gas blowing during degassing by the gas replacement method cover the can body so that the open end of the peripheral wall of the can body is in contact with the back surface of the lid flange. A slight gap is formed between the lid and the can body due to a pressure difference or the like, and the gap is formed through this gap.

[0005]

However, in the conventional metal lid, the sealing compound is applied to the back surface of the flange, and the opening end of the peripheral wall of the can body is in contact with the sealing compound of the lid. There is a problem that the lid is hardly lifted from the can body at the time of blowing and when the inert gas is blown, the efficiency is deteriorated, and the time required for lowering the air amount in the can to a required level is increased. In addition, there is a problem that the amount of air in the can cannot be reduced to a required level. In addition, since the sealing compound has tackiness at room temperature, when the vacuum degassing and the blowing of the inert gas,
There is a problem that the contents such as tea leaves adhere to the sealing compound and the sealing property after winding is reduced.

An object of the present invention is to provide a metal lid for a can which has solved the above-mentioned problems.

[0007]

SUMMARY OF THE INVENTION A metal lid for a can according to the present invention is a metal lid for a can which is fixed to an open end of a can body by tightening, and has a concave portion fitted into the opening of the can body. Provided, a flange is provided continuously to the peripheral wall of the concave portion,
A metal cover body provided with a curl connected to the tip of the flange, and a cover molding adhered to the back surface of the cover body and covering the back surface of the recessed peripheral wall of the cover body and the back surface of the flange. The exposed surface of the molded body opposite to the surface adhered to the lid body is formed of a synthetic resin that is non-tacky at room temperature and exhibits adhesiveness when heated, and covers a back surface of the concave peripheral wall of the molded body for covering. A gas passage is formed on the surface facing the can body side of the above.

In the above description, examples of the molded article for covering include a sheet (including a film, the same applies hereinafter) entirely formed of a polyolefin-based thermoplastic resin such as a polyethylene resin or a polypropylene resin, and a polyethylene terephthalate resin layer having both sides made of polyethylene. A laminated sheet covered with a polyolefin-based thermoplastic resin layer such as a resin or a polypropylene resin, and an aluminum foil (including an aluminum alloy foil; the same applies hereinafter) both sides of which are covered with a polyolefin-based thermoplastic resin layer such as a polyethylene resin or a polypropylene resin. Aluminum foil composite laminate, one side of the aluminum foil is covered with a hot melt layer that is non-tacky at room temperature and exhibits adhesiveness when heated, and the other side is a polyolefin-based thermoplastic resin layer such as polyethylene resin or polypropylene resin. Those formed from a sheet-like material such as cracking aluminum foil composite laminate is used. In the case of using the aluminum foil composite laminate having a hot melt layer, the hot melt layer is formed on the exposed surface of the portion covering the back surface of the recessed peripheral wall and the back surface of the flange.

The can body is made of a metal, a composite material mainly composed of metal, paper, a composite material mainly composed of paper, a plastic, a composite material mainly composed of plastic, or the like.

[0010]

According to the present invention, there is provided a metal lid body, and a cover molding adhered to the back surface of the lid body and covering the back surface of the concave peripheral wall of the lid body and the back surface of the flange. If the exposed surface opposite to the exposed surface is formed of a synthetic resin that is non-tacky at room temperature and exhibits adhesiveness when heated, when degassing in a vacuum / gas replacement method, vacuum degassing method, During gas injection in a vacuum / gas replacement method, gas injection method, or the like, the lid is easily lifted from the can body due to a pressure difference between the inside and outside of the can body, and a gap is formed between the two.
Therefore, degassing or gas blowing can be efficiently performed through this gap. Moreover, on the surface facing the can body side of the portion covering the concave portion peripheral wall back surface in the coating molded body,
When the gas passage is formed, degassing or gas blowing can be performed more efficiently.

Further, if the exposed surface of the molded body for coating opposite to the surface adhered to the lid body is made of a synthetic resin which is non-tacky at room temperature, the tea can be removed during degassing or gas blowing. Is prevented from adhering to the back surface of the flange portion of the lid.

Further, if the exposed surface opposite to the surface adhered to the lid main body of the covering molded body is formed of a synthetic resin exhibiting adhesiveness when heated, the lid is fixed to the can body by winding. Thereafter, when the wound portion is heated, the synthetic resin exhibits adhesiveness, and the both side portions are adhered through the synthetic resin.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same components and portions will be denoted by the same reference symbols throughout the drawings, and description thereof will be omitted.

Embodiment 1 This embodiment is shown in FIG. 1 and FIG. In the figure, the metal cover for a can (1) has a recess (3) fitted into the opening of the can body, and the flange (4) is connected to the peripheral wall (3a) of the recess (3). A metal lid body (2) provided with a curl (5) connected to the tip of the flange (4);
It is adhered to the back surface of the lid body (2) by, for example, an adhesive or a heat seal, and the back surface of the peripheral wall (3a) and the bottom wall (3b) of the concave portion (3) of the lid body (2) and the flange (4). )
And a covering molding (6) for covering the back surface of the above.

The lid body (2) is made of, for example, steel, aluminum or the like, the surface of which is subjected to a rust-proof treatment.

The molded body for coating (6) has substantially the same shape as that of the lid body (2), and a hot-melt layer having one side of an aluminum foil (7) that is non-tacky at room temperature and exhibits adhesiveness when heated. (8) covered with polyethylene resin layer on the other side (9)
The aluminum foil composite laminate (10) covered with is drawn and formed so that the hot melt layer (8) is on the outside, and the lid body (2)
This is formed by making the shape substantially the same as the shape of FIG. From the portion (6a) that covers the back surface of the peripheral wall (3a) of the concave portion (3) of the lid body (2) in the molding (6) for covering,
Over the portion (6b) covering the back surface of (4), a plurality of overlapping portions (11) in which the aluminum foil composite laminate (10) partially overlaps and protrudes outward are formed at intervals in the circumferential direction. . The part between the adjacent overlapping parts (11) is the gas passage (1
2) has been done.

FIGS. 3 to 6 show a method of enclosing tea leaves in a can in the order of steps by applying, for example, a vacuum degassing / gas replacement method. In advance, a lower end opening is formed by fixing a separately formed bottom lid (16), or a flange (15a) at an upper end portion of a peripheral wall of a can body (15) closed by a bottom wall formed integrally. It is formed. After filling the contents (S) into the can body (15), the lid (1) is placed so that the flange (15a) of the can body (15) is in contact with the back surface of the flange (1a) of the lid (1). Is put on the can body (15), and temporary winding is performed (see FIG. 3). At this time, the protruding end of the overlapping portion (11) of the portion (6a) covering the peripheral wall (3a) of the concave portion (3) of the lid body (2) in the covering molding (6) is A plurality of gas passages (12) in contact with the surface and between the can body (15)
Exist (see FIG. 4). In addition, moldings for coating (6)
The protruding end of the overlapping portion (11) of the portion (6b) covering the flange (4) of the lid body (2) is in contact with the tip of the flange (15a) of the can body (15). The above-mentioned temporary winding is performed in order to prevent the lid from being displaced during the vacuum deaeration and the blowing of the inert gas in the subsequent process, and the lid (1) is lifted during the vacuum degassing and the blowing of the inert gas. You can do it.

Next, the can body (15) with the lid (1) temporarily tightened
Into the vacuum chamber (17), and evacuate (not shown)
The valve (19) provided in the exhaust passage (18) is opened, and the inert gas supply passage of the inert gas supply device (not shown) is opened.
The valve (21) provided in (20) is closed, the pressure in the chamber (17) is reduced using a vacuum pump (not shown), and the inside of the can body (15) is evacuated (see FIG. 5). At this time, first, since the pressure outside the can body (15) becomes lower than the pressure inside the can body (15), as shown in FIG.
It floats up easily from 5), and a gap is formed between the two, and deaeration is efficiently performed through this gap. In addition, degassing can be carried out more efficiently by the function of the gas passage (12) of the molding (6).

After the pressure is reduced to a predetermined degree of vacuum, the vacuum pump is stopped, the valve (19) is closed, the valve (21) is opened, and the vacuum chamber (17) is supplied by an inert gas supply device such as nitrogen gas. An inert gas is blown into the inside, and the inside of the vacuum chamber (17) is returned to normal pressure. At this time, first, the pressure outside the can body (15) becomes lower than the pressure inside the can body (15) .Therefore, the lid (1) easily lifts up from the can body (15) due to these pressure differences, and between them. A gap is formed (see FIG. 6), and the inert gas is efficiently fed through this gap. In addition, the function of the gas passage (12) of the molding (6) for coating allows
The feeding of the inert gas is performed more efficiently.

Then, the lid (1) is fixed to the can body by the double winding method.
Fix to (15). In addition, at the time of the above-mentioned vacuum degassing and at the time of injecting the inert gas, a part of the contents (S) together with the gas causes
5) The body of the cover (6)
The exposed surface opposite to the surface bonded to (2) is covered with a hot-melt layer (8) that is non-tacky at room temperature and exhibits adhesiveness when heated, so that the contents (S) are (1) is prevented from adhering to the back surface of the flange (1a). Therefore,
It is possible to prevent a part of the contents (S) from remaining in the wound portion at the time of double winding.

Finally, the seam is heated so that the hot melt layer (8) becomes adhesive and is sealed.

In this embodiment, the molded article for coating (6)
The overlapping portion (11) is also formed in the portion (6b) covering the flange (4) of the lid body (2) in the above, and the gas passage (12) is formed. It is not necessary.

Embodiment 2 This embodiment is shown in FIG. In FIG.
Recessed part of lid body (2) in covering molding (6) of (25)
In the portion (6a) covering the back surface of the peripheral wall (3a) of (3), a plurality of ridges (26) extending in the vertical direction are formed at intervals in the circumferential direction. And the part between the adjacent ridges (26) is the gas passage
(27). In this embodiment, each ridge (26) may be formed so as to reach a portion (6b) covering the flange (4) of the lid body (2) in the covering molded body (6). . Further, a plurality of concave grooves may be formed instead of the ridges (26). In this case, the inside of the concave groove becomes a gas passage.

Embodiment 3 This embodiment is shown in FIG. In FIG.
Depression of lid body (2) in molding (6) for covering (28)
A plurality of ridges (29) extending in the circumferential direction are formed in a staggered manner on a portion (6a) covering the back surface of the peripheral wall (3a) of (3). A portion between the adjacent ridges (29) is a gas passage (30).

Embodiment 4 This embodiment is shown in FIG. In FIG.
Recessed part of lid body (2) in covering molding (6) of (31)
Part (6a) and flange covering the back of the peripheral wall (3a) of (3)
A large number of projections (32) are formed on the portion (6b) covering the back surface of (4). The portion between the projections (32) is the gas passage (3
3) has been done. In this embodiment, the projection (32) may not be formed on the portion (6a) of the cover molding (6) that covers the flange (4) of the lid body (2).

The method of closing the upper end opening of the can body (15) by using the lids of the above-described second to fourth embodiments is the same as that of the first embodiment.

[0027]

According to the metal for cans of the present invention, as described above, when degassing in the vacuum / gas replacement method, vacuum degassing method, etc., or injecting gas in the vacuum / gas replacement method, gas blowing method, etc. At times, a gap is easily formed between the can body and the lid, so that degassing or gas blowing can be efficiently performed through the gap. Therefore, it is possible to shorten the time required for reducing the amount of air in the can to the required level, and to surely reduce the amount of air in the can to the required level. In addition, degassing or gas blowing can be performed more efficiently through the gas passage formed on the surface facing the can body side of the portion of the molding for covering that covers the rear surface of the concave peripheral wall.

In addition, the contents such as tea leaves are prevented from adhering to the back surface of the flange portion of the lid at the time of vacuum degassing and blowing of the inert gas, so that the sealing performance after tightening is reduced. Can be prevented.

Further, after the lid is fixed to the can body by winding and then the tightened portion is heated, the synthetic resin forming the exposed surface opposite to the surface adhered to the lid main body of the covering molding has an adhesive property. So that both side parts are bonded through this. Therefore, the winding portion is completely sealed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a metal lid for a can of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a vertical sectional view showing a state where a lid is temporarily wound around a can body in a vacuum degassing / gas replacement method.

FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a vertical sectional view showing a state where vacuum degassing is performed in a vacuum degassing / gas replacement method.

FIG. 6 is a vertical sectional view showing a state where an inert gas is blown in the same manner.

FIG. 7 is a perspective view showing Embodiment 2 of the metal lid for a can of the present invention.

FIG. 8 is a perspective view showing Embodiment 3 of the metal lid for a can of the present invention.

FIG. 9 is a perspective view showing Embodiment 4 of the metal lid for a can of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal lid for cans 2 Metal lid main body 3 Concave part 3a Peripheral wall 4 Flange 5 Curl 6 Coating molded body 6a Part covering the back surface of concave perimeter wall 8 Hot melt layer (synthetic resin) 12 Gas passage 15 Can body 25 Can Metal lid 27 Gas passage 28 Metal lid for can 30 Gas passage 31 Metal lid for can 33 Gas passage

Claims (1)

(57) [Scope of request for utility model registration] 1. A metal lid for a can fixed to the open end of a can body by winding and fastening, the metal cover having a recess fitted into the opening of the can body, and a flange connected to a peripheral wall of the recess. A metal lid main body provided with a curl connected to the tip of the flange, and a covering molding adhered to the back surface of the lid main body and covering the back surface of the recessed peripheral wall of the lid body and the back surface of the flange. The exposed surface of the cover molding opposite to the surface adhered to the lid body is formed of a synthetic resin that is non-tacky at room temperature and exhibits adhesiveness when heated, and the concave portion peripheral wall back surface of the coating molding is formed. A metal lid for a can, in which a gas passage is formed on a surface facing a can body side of a portion covering the can.