JPH0617124B2 - How to seal the lid of a can - Google Patents

Description

The present invention relates to a method for continuously virgin-sealing a covered surface of a stacking can.

[Prior Art] Canned beer and canned coffee packed in stackable cans are sold at vending machines for easy drinking, but the covered surface of cans with pull-tops is dusty or dusty. , Or bacteria are attached, so capping is conventionally performed for hygiene. As a method thereof, generally, a non-stretched thermoplastic resin is vacuum-formed, and the can is simply covered by fitting. Therefore, these containers have the drawback that they have no virgin function at all, such as during transportation and at the storefront, because dust and bacteria enter through the gaps to contaminate them and the caps come off.

As a cap having adhesion, there is a capping method using a biaxially stretched thermoplastic resin film or sheet (hereinafter abbreviated as heat shrink film), but this is limited to a flat top surface, If a cap with a flat top surface is capped on the covered surface of the can, there is a drawback that it becomes difficult to stack the cans when arranging them in a store.

[Problems to be Solved by the Invention] The present invention provides a method for continuously sealing a cap body having a virgin sealing property, capable of stacking, and not displaced during transportation to a can. is there.

[Means for Solving the Problems] In the present invention, first, a heat-shrinkable film is continuously formed into a cap body having a specific shape, the heat-shrinkable film is continuously placed on a lid surface of a stacking can, and then the cap body is placed. This is a series of methods for continuously heat-shrinking and closely adhering.

That is, the present invention relates to [1. In a method of virgin sealing the covered surface of a stacking can, 1). The heat-shrinkable film 1 is pressed against the continuous rotary molding drum 6 by a clamp 4 of an arc-shaped heating device 2 having an inner peripheral surface that is substantially the same as the outer peripheral surface of the molding drum 6 near both ends in the width direction of the film. , A preheating step A for continuously feeding to the molding step B while preheating while protecting so as not to shrink even under the influence of heat, 2). The preheated film is brought into close contact with a vacuum forming mold 7 having an inner peripheral surface having an almost same shape as the covered surface of the stacking can, which is open to the outer peripheral surface of the continuous rotary forming drum 6, and the film is adhered to the film. Forming step B in which the inside of the forming die is depressurized and vacuum forming is continuously performed while pressing the vicinity of both widthwise end portions with the clamp 4 against the continuous rotary forming drum 6. Then, the heating device is detached from the forming drum, and a cutting step C for cutting the formed film into a cap shape, 4). A transfer step D in which the cut cap body 14 is transferred to the capping step E while being stored in the molding die, 5). Capping process E of the can with the contents filled and the lid covered
With a transfer device that transfers the
Capping step E in which the molded cap body is detached from the molding die and placed, 6). While pressing the upper surface of the cap body with a pressing tool and protecting it from hot air at the same time, hot air is blown from around the sleeve of the cap body to shrink the cap body, and the shrinking process F that brings the sleeve periphery into close contact with the peripheral wall of the can is combined. The method of sealing the lid of the can.

2. The method for sealing the lid of a can according to item 1, wherein the heat-shrinkable film 1 is a film having an adhesive layer on the side facing the can wall. It is.

EXAMPLES The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view of a preferred embodiment of the method of the present invention, and FIG. 3 is a plan view thereof.

Thickness 15 to 2 formed of a single layer of polyvinyl chloride, polyethylene, polypropylene, polystyrene, polycarbonate, polyester, etc. or a composite using these.
00 μm, biaxially stretched at a stretch ratio of 1.01 to 10 times,
The thermoplastic resin film is continuously sent to the preheating step A and wound around the rotational molding tram 6.

A plurality of vacuum forming dies 7 are provided on the peripheral surface of the forming drum so as to open outward.

This vacuum forming mold has an inner peripheral surface having substantially the same shape as the covered surface of the stacking can, and therefore exhibits the same unevenness as the covered surface of the stacking can.

FIG. 2 is a view of the heating device as viewed from below.

By the clamp 4 installed on the inner peripheral surface of the arc-shaped heating device 2 having an inner peripheral surface that is substantially the same as the outer peripheral surface of the molding drum 6, which is reciprocating along the peripheral surface of the molding drum 6,
The molding drum 6 on which the heat-shrinkable film is pressed in the vicinity of both ends in the width direction so as not to heat-shrink, is rotated together with the heating device 2 in the direction of the arrow 20, and the upper surface of the heat-shrinkable film is pressed. 60 ~ 200 ℃ installed in the heating device 2
The film is preheated while moving the heating platen 3 of (1) and moving together with the heat shrinkable film, and then heated to a temperature at which the heat shrinkable film can be formed.

When the molding drum 6 rotates to enter the molding process B, the vacuum region 8
The inside of the molding die is depressurized by this, and the heat-shrinkable film is continuously molded to provide the continuous film 10 on which the target cap body is formed.

When the forming drum 6 further rotates and enters the cutting step C, the cutting device 11 that reciprocates along the peripheral surface of the forming drum 11.
By the punching blade 12 attached to, the unnecessary portion of the formed film is cut and the cap body is punched while running in parallel with the drum.

Although the cap bodies are shown to be cut one by one in the drawings, it is of course possible to cut a plurality of cap bodies simultaneously and continuously.

The punched molded film 14, that is, the cap body 1.
4 is transferred to the capping process E by the rotation of the drum while being stored in the molding die installed on the molding drum.

On the other hand, the remaining film 13 with the cap body punched out
Is discharged out of the system in the middle of the cutting process and the capping process.

When the molding die accommodating the cap body 14 is transferred to the capping step, as shown in FIG.
Is synchronized and adjusted so that the covered surface of the stacking can 15 that has been conveyed by the above-mentioned can arrive right below, and the cap body is separated from the molding die by the air pressure from the pressurizing region 9 and the covered surface of the stacking can. Can be posted on.

The stacking can 16 on which the cap body is placed is transferred to the shrinking process F and sealed.

Details of the operation in the shrinking process are shown in FIG.

Reference numeral 21 denotes a shrink rotary table attached to the shrink device 19.

The stacking can 16 on which the cap body is placed is transferred from the carrying device 18 to the rotary table, the upper surface of the cap body is pressed by the cap body pressing plate 22 having cushioning property, and the bottom of the stacking can is pressed by the can bottom receiving plate 26. 2-4 minutes per minute
While rotating, the sleeve portion of the cap body 24 is shrunk by blowing hot air from the side surface and diagonally from above, and is brought into close contact with the upper wall portion of the stacking can.

At this time, since the cooling water 23 is passed through the cap body pressing plate 22 to cool it, the flat portion of the top surface of the cap body is protected from hot air and is not contracted and deformed.

At this time, if a heat-shrinkable film provided with an adhesive layer, such as a hot-melt adhesive such as ethylene-vinyl acetate copolymer resin on the side facing the can wall, is used, the adhesiveness is further improved. Even if the cans that have been sealed with water are soaked in ice water, the seals will not peel off or water will not enter.

[Effect of the Invention] According to the method of the present invention, the bottom flange portion of the stacking can and the cover for the virgin sealing are formed by using the cap body in which the heat-shrinkable film is formed in advance in substantially the same shape as the covered surface of the stacking can. Since the projections of the parts fit well with each other, they can be stacked in multiple stages when they are displayed in a store or the like.

Since it uses a heat-shrinkable film, it can be adhered to the upper wall of the can and cannot be peeled off from the can unless it is broken, so the virgin sealing function is extremely high.

The advantage of the method of the present invention is that the continuous rotating drum 6 is pressed by the clamp 4 provided in the arc-shaped heating device 2 having the inner peripheral surface substantially the same as the outer peripheral surface of the continuous rotating drum 6. This means that a series of steps of vacuum-forming the heat-shrinkable film so as not to heat-shrink, capping the heat-shrinkable film on the covered portion of the stacking can, and performing virgin sealing are continuously performed. As a result, productivity was improved several times as compared with the conventional method.

[Brief description of drawings]

1 and 3 are a side view and a plan view showing an embodiment of the method of the present invention. FIG. 2 is a view of the heating device as viewed from below. FIG. 4 is a side view showing details of the operation in the shrinking process. 1 ... Heat shrink film, 2 ... Heating device, 3 ... Heating plate, 4 ... Clamp, 6 ... Molding drum, 7 ... Vacuum forming mold, 8 ... Vacuum region, 9 ... Pressurizing Area, 10 ... molded film, 11 ... cutting device, 12 ... punching blade, 13 ... scrap film, 14 ... cut molded film (cap body), 15 ... covered can, 1
6 ... can on which cap body is placed, 17 ... can on which cap body is shrunk, 18 ... conveying device, 19 ... shrink device, 20 ... arrow (direction of rotation of molding tram), 2
1 ... Shrinking rotary table, 22 ... Cap body pressing plate (self-rotating type, 2 to 4 rotations), 23 ... Cooling water, 2
4 ... Cap body, 25 ... Stacked can (self-rotating type, 2
4 rotations) 26 ...... can bottom plate, 27 ...... hot air, 28 ......
A sleeve with a shrink cap.

Claims (2)

[Claims] 1. A method of virgin-sealing a covered surface of a stacking can, 1). The heat-shrinkable film 1 is pressed against the continuous rotary molding drum 6 by a clamp 4 of an arc-shaped heating device 2 having an inner peripheral surface that is substantially the same as the outer peripheral surface of the molding drum 6 near both ends in the width direction of the film. , A preheating step A for continuously feeding to the molding step B while preheating while protecting so as not to shrink even under the influence of heat, 2). The preheated film is brought into close contact with a vacuum forming mold 7 having an inner peripheral surface having an almost same shape as the covered surface of the stacking can, which is open to the outer peripheral surface of the continuous rotary forming drum 6, and the film is adhered to the film. Forming step B in which the inside of the forming die is depressurized and vacuum forming is continuously performed while pressing the vicinity of both widthwise end portions with the clamp 4 against the continuous rotary forming drum 6. Then, the heating device is detached from the forming drum, and a cutting step C for cutting the formed film into a cap shape, 4). A transfer step D in which the cut cap body 14 is transferred to the capping step E while being stored in the molding die, 5). Capping process E of the can with the contents filled and the lid covered
With a transfer device that transfers the
Capping step E in which the molded cap body is detached from the molding die and placed, 6). While pressing the upper surface of the cap body with a pressing tool and protecting it from hot air at the same time, hot air is blown from around the sleeve of the cap body to shrink the cap body, and the shrinking process F that brings the sleeve periphery into close contact with the peripheral wall of the can is combined. The method of sealing the lid of the can. 2. The method for sealing a lid of a can according to claim 1, wherein a film having an adhesive layer provided on the side facing the can wall is used as the heat-shrinkable film 1.