JP4299741B2 - Canning apparatus and method for preventing hair generation - Google Patents

Description

  The present invention relates to a can-making apparatus and a can-making method for forming a can body from a plate material having an organic coating layer formed on at least one side of a base material made of a metal material. More specifically, the present invention relates to an organic material on at least one side of a base material. A can-making apparatus and a product for preventing a coating film hair and a film hair that are generated when a primary drawn molded body (cup), a redraw-molded can, and a re-draw-molded can are produced using a plate material on which a coating layer is formed. It relates to the can method.

  Drawing cans (see, for example, Patent Document 1), thinned redrawn cans (for example, Patent Documents 2 and 3) used for canned foods such as carbonated beverage cans, juice cans, coffee beverage cans or solid food cans such as jelly Reference), when forming a seamless can such as a thinned redrawn-ironing can (see, for example, Patent Document 4), a can lid (see, for example, Patent Document 5), and the like, at least one surface (usually both surfaces) of the metal layer A blank is punched out from a plate with an organic coating layer formed on it by punch and die cooperation, and immediately drawn in the same process to form a primary drawn body (hereinafter referred to as cup) and then seamless in the next process. A method of forming a can body and a can lid is employed.

  On the edge of the seamless can body and can lid formed in this way (in the case of a seamless can body, the edge of the flange portion, in the case of a can lid, the edge of the curled portion) Hereinafter, many organic coating hairs (usually having a length of about 10 mm or more) are likely to occur (see Patent Document 6). This organic coat hair peels off from the edge, remains attached to the inner surface of the can, fills and seals the contents, becomes canned, and is found harmless when found as a foreign object, but is suspected of being unsanitary. Easily subject to complaints. For this reason, cans with organic coating hair found by 100% inspection are rejected. Therefore, there arises a problem that the product yield is lowered. In addition, there is a possibility that the organic film hair on the can lid may enter the can during sealing. In addition, it may fall off during the can manufacturing process and may enter between the tool and the can body to cause a film defect, resulting in a problem of deterioration in the quality of the can body and the can lid.

The cause of the occurrence of the organic film hair is as described in Patent Document 7, and is explained in detail by taking as an example the production of a thinned redrawn-ironing can.
In the method of punching into a blank as a hair prevention method, at least at the time when the plate material and the punch come into contact with each other and start punching, the peripheral portion near the cutting edge of the punch end face that passes through the organic coating layer in contact with the punch and the cutting edge of the punch There is a tool proposal (see Patent Document 7) that is set so that the angle between the tangent line and the tangent line is 3 to 60 degrees, but when the cutting edge is worn, especially when the organic film is thick or soft In fact, these proposals cannot completely prevent hair.
In addition, as an example of proposing laser irradiation to a can-making material, the inventors of the present invention remove an unnecessary resin by irradiating an infrared pulse laser to a resin-free portion of the material for a welding can (see Patent Document 8). Disclosed.

  The principle of resin removal by a laser is based on the evaporation and vaporization of the resin. Therefore, the generation of resin vapor is inevitable. When the resin vapor floats on the laser optical axis, the laser light is absorbed and an abnormal exothermic reaction occurs. As a result, there arises a problem that the resin that does not need to be removed melts or adheres to the surface in a bowl shape. Therefore, it is necessary to quickly remove the evaporated resin particles from the laser optical axis. However, if the removed resin vapor particles are reattached to the cup surface, there is a possibility of affecting the odor and the slipperiness of the surface. In particular, there is a problem that if the odor adheres to the cup, it cannot be used for beverage cans and food cans. In addition, when the surface properties such as slip properties change, there is a problem that the surface flaws and deformation are likely to occur in the subsequent deep drawing process, and the yield decreases. Therefore, there is a need for a processing apparatus that removes the resin vapor generated in the laser irradiation section quickly and without touching the steel sheet surface. As a removal method, it is easy to blow high-pressure gas directly on the processing part. However, with simple gas blowing, it is difficult to control and completely recover the gas flow so that the scattered vapor does not re-adhere to the steel plate. It is. In addition, a device that reliably prevents the resin vapor from adhering to a special shape such as an edge of the inner wall of the cup is necessary for the laser irradiation part.

Further, in the laser processing apparatus, in order to prevent the melt from scattering to the surroundings, a nozzle body is provided that sucks a substance generated by supplying a shielding gas toward the workpiece and irradiating the laser beam. A laser processing apparatus is disclosed in Patent Document 9. However, the invention disclosed in Patent Document 9 is provided with a suction path around the nozzle, and there is no description about irradiating a laser to a can end portion used for a beverage can or a food can. .
Japanese Patent Publication No. 60-11576 Japanese Patent Laid-Open No. 3-155419 JP-A-4-324826 JP-A-7-275961 Japanese Patent Publication No. 3-58814 JP 58-16848 A JP 2000-167625 A JP 7-290258 A JP-A-8-192289

  An object of the present invention is to provide a coating film hair or a film hair that is generated when a cup molding, a redrawn can, and a redrawn and ironed can are manufactured using a plate material having an organic coating layer formed on at least one side of a substrate. In the apparatus and method for evaporating and removing a part of the resin layer that becomes a hair element by laser irradiation, in particular, it is possible to prevent the vaporized resin vapor from reattaching to the surface of the plate material. An object of the present invention is to provide a can-making apparatus and a can-making method that do not cause changes in odor and surface properties caused by steam.

(1) In an apparatus for manufacturing a metal container by cutting a metal plate coated with a resin film on at least one surface into a disk shape, cup molding and drawing ironing, an apparatus for irradiating a laser to the inner wall of the cup edge a gas injection nozzle for supplying a gas toward the cup bottom, and a gas suction and discharge nozzles for sucking and discharging the gas flowing from the cup bottom to the cup edge, the gas injection nozzle and the gas sucked and The discharge nozzle has a concentric cylindrical shape, the diameter of the gas injection nozzle is smaller than the diameter of the cup, and the diameter of the gas suction / discharge nozzle is equal to or larger than the diameter of the cup to prevent the occurrence of resin hair Can-making equipment.
(2) The laser irradiation device is a rotary mirror, and the rotary mirror is disposed on the central axis of the concentric cylindrical gas injection nozzle and the gas suction / discharge nozzle and inside the gas injection nozzle. A can-making device that prevents the occurrence of resin hair according to (1).
(3) The concentric cylindrical gas injection nozzle and / or part of the gas suction / discharge nozzle is provided with a laser light transmission window, wherein the production of resin hair is prevented according to (1) or (2) Can equipment.
(4) The can-making apparatus according to (3), wherein at least one of the laser light transmitting windows has an fθ lens condensing function.
(5) Resin hair generation according to any one of (1) to (4), wherein a part or all of the gas injection nozzle and / or the gas suction / discharge nozzle is made of a laser light absorbing material. Can-making equipment to prevent.
(6) A metal plate coated with a resin coating on at least one side is cut into a disk shape, and after cup molding, gas is supplied toward the cup bottom , and the gas flow is directed from the cup bottom toward the cup edge. While irradiating the inner wall of the cup edge while forming to evaporate the resin coating in the vicinity of the cup edge and discharging the evaporated resin coating to the outside, a metal container is produced. A can-making method that prevents the generation of resin hair.

  According to the present invention, in a can-making apparatus for a resin-coated metal plate, it is possible to remove the resin that becomes a hair element by laser irradiation and to prevent the resin vapor from re-adhering to the steel sheet surface as much as possible. A stable can can be implemented without causing problems such as odor.

The present invention will be described below with reference to examples.
FIGS. 1 and 2 are explanatory views of a laser irradiation apparatus for removing a part of the resin at the edge of the cup which becomes a hair element after forming the cup by laser irradiation. FIG. 1 shows an example in which a rotating mirror is used. In FIG. 1, a laser beam 1 output from a laser device (not shown) is collected by a condenser lens 2 and passes through a mirror support cylinder 3 and is fixed by a mirror (device for laser irradiation) 4. Reflected. The laser beam passes through the laser passage opening or transmission window 17 of the cylindrical body 3. By rotating the cylindrical body 3, the laser beam is reflected radially about the central axis 12 and is irradiated onto the edge 7 of the inner wall of the cup 6. The resin that has absorbed the laser beam is instantly evaporated and part or almost all of the resin is removed.

  FIG. 2 shows an example in which a vibrating mirror 14 and an fθ lens 16 are used as a laser irradiation device. The fθ lens is a lens designed so that a laser beam scanned by a vibrating mirror or the like has a condensing point on the same plane. In FIG. 2, the laser beam 1 is reflected by two vibrating mirrors 14. The vibrating mirror is vibrated by a galvanometer motor (not shown). Each mirror vibrates in a direction orthogonal to each other to scan the reflected beam in an annular shape. The scanned beam is condensed by the fθ lens 16 and irradiated to the edge 7 of the inner wall of the cup 6. The resin that has absorbed the laser beam is instantly evaporated and part or almost all of the resin is removed.

The present inventors examined an apparatus in which the particles of the evaporating resin do not completely come into contact with the inner wall of the cup that is in direct contact with food or beverage after canning, with regard to resin removal at the edge of the inner wall of the cup. As a result, gas is always applied from the bottom of the cup to the edge using the cup shape so that the inside of the cup has a higher pressure than the surroundings, that is, a negative pressure from the edge to the outside of the cup. Invented an apparatus and a method for forming a stream .

  FIG. 3 shows a first embodiment of the present invention. The laser beam 1 is output from a laser device (not shown), collected by the lens 2, passes through the cylindrical body 3, is reflected by the rotating mirror 4, and then passes through a laser passage opening or window 17 provided in the cylindrical body 3. Passes and radiates radially to the inner wall of the cup. As a result, the resin of the cup inner wall edge 7 is removed by evaporation. The rotating mirror 4 is fixed to the cylindrical body 3, and the cylindrical body 3 is fixed via a bearing 5 and is rotated by a motor (not shown). The cylindrical body 3, the gas injection nozzle 8, and the gas suction / discharge nozzle 9 are arranged concentrically around the cup central axis 12, that is, the rotating mirror 4. The gas is, for example, high-pressure air, passes through the gas injection nozzle 8 from the gas inlet 10, passes through the gas suction / discharge nozzle 9 from the bottom of the cup and the inner wall of the cup toward the cup edge 7. It is discharged from the gas discharge port 11. The discharge port is connected to a gas discharge device such as a vacuum pump (not shown), and the gas flow is adjusted at a laser irradiation unit so as to become a predetermined speed or more by the balance between the injection gas pressure and the suction force. In addition, it is preferable to provide a gas inlet 10 in the cylindrical body 3 to introduce gas into the cylindrical body 3 and prevent gas from flowing into the cylindrical body 3.

In the apparatus of the present invention, the inside of the cup becomes a high pressure (> 1.02 × 10 ⁵ Pa) that is equal to or higher than the atmospheric pressure, so that the resin vapor generated at the edge does not flow into the cup, and the gas injection nozzle 8 By setting the diameter to be smaller than the diameter of the cup 6 and the diameter of the gas suction / discharge nozzle 9 to be equal to or larger than the diameter of the cup 6, the gas flow substantially flows along the cup shape. As a result, the inside of the cup is completely shielded from the resin vapor, and the reattachment of the evaporated resin can be prevented.

  Further, as shown in FIG. 3, a part of the laser beam irradiated to the cup edge 7 is reflected without being absorbed by the resin. When this reflected laser beam 13 is irradiated to the bottom of the cup, a problem of damaging the resin occurs. In the apparatus of the present invention, it is preferable to use a laser light absorbing material (laser light non-reflective material) for part or all of the gas injection nozzle 8 and the rotating cylindrical body 3 placed in the cup, since such problems can be solved. . As the laser light non-reflective material, an aluminum material whose surface is black anodized or black paint is suitable. Further, a laser beam that is transmitted without being irradiated to the edge portion of the cup is preferable because the gas suction / discharge nozzle 9 is made of the same material to prevent laser irradiation to an unnecessary portion outside the cup.

  FIG. 4 shows a second embodiment of the present invention. The introduction path of the laser beam is the same as in the first embodiment. The high-pressure gas passes through the inside of the cylindrical body 3 from the gas inlet 10 and is further introduced to the gas injection nozzle 8 provided at the lower part of the rotating mirror 4, and flows from the bottom of the inner wall of the cup toward the cup edge 7. . That is, structurally, the cylindrical body 3 also serves as the gas injection nozzle 8. The gas that has passed through the edge 7 and the resin vapor generated by laser irradiation are sucked and discharged from the gas discharge port 11. The gas discharge port 11 is connected to the exhaust device as in the first embodiment. The cylindrical body 3 is held by a bearing 5. In this apparatus, the gas flow from the bottom of the cup inner wall portion to the cup edge is more reliably formed, effectively preventing the cup inner wall from coming into contact with the resin vapor, and preventing the reattachment of the evaporated resin.

In the present embodiment, the laser transmitting window 17 is preferably a hermetic window material so as not to disturb the gas flow inside the cylindrical body 3. The window material is selected according to the wavelength of the laser used. For example, ZnSe with a non-reflective coating is suitable when using a CO ₂ laser, and quartz glass with a non-reflective coating is suitable when using a YAG laser.
Similarly to the first embodiment, in this embodiment, the material of the cylindrical body 3 and the gas suction / discharge nozzle 9 is made of a laser light non-reflective material, so that it is possible to prevent laser irradiation to unnecessary portions. It is.

FIG. 5 shows a third embodiment of the present invention. As in the first and second embodiments, the gas injection nozzle 8 and the gas suction / discharge nozzle 9 are concentric cylinders. Furthermore, in the apparatus of the present invention, as shown in the figure, each nozzle is provided with a laser transmitting window 15 that transmits laser light and has a sealing property. As the laser transmission window, for example, when using a CO ₂ laser, ZnSe is used as the material and the surface is coated with antireflection coating. When using YAG laser, quartz glass is applied with antireflection coating. It is. The laser beam is condensed by the lens 2, scanned in an annular shape by the two vibrating mirrors 14, passes through the laser transmission window 15, and is applied to the cup edge 7. In this apparatus configuration, as shown in the figure, the gas flow passes through the injection nozzle 8 and passes through the bottom of the cup and is discharged from the gas suction / discharge nozzle 9. Adhesion can be prevented. Further, since the laser irradiation device is independent of the gas injection nozzle and the gas suction / discharge nozzle, the laser irradiation device is not limited to the rotating mirror, and the method shown in FIG. 5, the method using the fθ lens shown in FIG. Any method that irradiates the laser beam in an annular shape can be used.

  Similarly to the previous embodiment, in this embodiment, the cylindrical body 3 and the gas suction / discharge nozzle 9 are made of a non-reflective material for the laser beam, so that unnecessary portions can be prevented from being irradiated with laser. It is.

  FIG. 6 shows a fourth embodiment of the present invention. The present embodiment corresponds to another form of the third embodiment. In this embodiment, the laser irradiation apparatus is an apparatus using the vibrating mirror 14 and the fθ lens 16. In this apparatus, it is possible to simplify the apparatus by sharing one piece of the laser transmission window 15 with the fθ lens 16, and it is possible to reduce the laser power loss generated in the window by a small amount because the laser transmission window is small. It is.

It is an explanation of a method of removing unnecessary resin by irradiating a laser on the inner wall of a cup with a laser. It is an explanation of a method for removing unnecessary resin by irradiating a laser on the inner wall of a cup using a vibrating mirror and an fθ lens. It is a figure which shows the 1st example of this invention apparatus. It is a figure which shows the 2nd example of this invention apparatus. It is a figure which shows the 3rd example of this invention apparatus. It is a figure which shows the 4th example of this invention apparatus.

Explanation of symbols

1 Laser beam 2 Condensing lens 3 Mirror support cylinder (cylindrical body)
4 Rotating mirror (laser irradiation device)
5 Bearing 6 Cup formed from resin-coated steel plate 7 Laser irradiation part (cup edge)
8 Gas injection nozzle 9 Gas suction / discharge nozzle 10 Gas inlet 11 Gas outlet 12 Cup central axis (central axis of concentric cylindrical nozzle)
13 Reflected laser beam 14 from cup edge edge Vibrating mirror 15 Laser light transmitting window 16 fθ lens 17 Laser passing aperture or window

Claims (6)

In a device for manufacturing a metal container by cutting a metal plate coated with a resin coating on at least one side into a disk shape, cup molding, drawing and ironing, a device for irradiating the inner wall of the cup edge, and a cup bottom And a gas suction / discharge nozzle for sucking / discharging the gas flowing from the cup bottom to the cup edge , and the gas injection nozzle and the gas suction / discharge nozzle are concentric. A can-making apparatus for preventing the occurrence of resin hair, characterized in that it has a cylindrical shape, the diameter of the gas injection nozzle is smaller than the diameter of the cup, and the diameter of the gas suction / discharge nozzle is not less than the diameter of the cup.   The laser irradiation device is a rotating mirror, and the rotating mirror is disposed on the central axis of the concentric cylindrical gas injection nozzle and the gas suction / discharge nozzle and inside the gas injection nozzle. The can-making apparatus which prevents resin hair generation | occurrence | production of Claim 1.   3. A can-making apparatus for preventing the occurrence of resin hair according to claim 1, wherein a laser beam transmitting window is provided in a part of the gas injection nozzle and / or the gas suction / discharge nozzle.   4. A can-making apparatus for preventing the occurrence of resin hair according to claim 3, wherein at least one of the laser light transmitting windows has an fθ lens condensing function.   5. A can making prevention of resin hair generation according to claim 1, wherein a part or all of the gas injection nozzle and / or the gas suction / discharge nozzle is made of a laser light absorbing material. apparatus. A metal plate coated with a resin coating on at least one side is cut into a disk shape, and after forming a cup , a gas is supplied toward the cup bottom while forming a gas flow from the cup bottom toward the cup edge. A resin hair characterized by irradiating a laser on an inner wall of a cup edge to evaporate a resin coating in the vicinity of the cup edge and discharging the evaporated resin coating to the outside, and then manufacturing a metal container A can-making method to prevent generation.

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