JP4587475B2 - Aseptic filling method using a can container that can be resealed with a cap - Google Patents

Description

  The present invention relates to an aseptic filling method for filling and sealing sterilized contents in a container sterilized in a substantially aseptic atmosphere, and in particular, using a can container that can be resealed (resealed) with a cap. Inside, the inside and outside surfaces of the can body with the can bottom side opened are sterilized, then the sterilized contents are filled from the can bottom side of the sterilized can body, and the can bottom side is sealed with a sterilized bottom lid It relates to the aseptic filling method.

For metal can containers such as bottle-shaped cans that can be resealed with caps with screws, the recycling rate of resources, light shielding, gas permeation resistance, rapid cooling, etc. In recent years, it has been widely used in the beverage can market containing various beverages because of its superiority. In such metal can containers, the filling and sealing of the contents using existing canning equipment After filling the contents from the can bottom side with the can body upside down, the bottom of the can body with the cap attached to the mouth and neck and the can bottom side opened, It has been conventionally known from Patent Document 1 below that a lid is wound and fixed to seal the bottom of the can.
JP-A-2002-128193

  By the way, in a can container that can be resealed (resealed) with a cap, when the contents are filled from the can bottom side as described above, the can body is in a state where the cap is attached to the mouth and neck and the can bottom side is opened. On the other hand, the contents are filled from the bottom of the can with the can body inverted so that the cap side is down. When filling with sterilized contents in a container that has been sterilized in the inside), the sterilizing agent is sprayed with hot air before filling the sterilized contents in an almost aseptic atmosphere. It is necessary to sterilize the inner and outer surfaces of the can body in advance by drying.

  On the other hand, in the conventional can container that can be resealed by the cap, in order to seal the open end of the mouth and neck portion side of the can body whose can bottom side is opened before filling and sealing the contents, A cap is already attached to the mouth and neck of the can body, and in order to ensure sufficient sealing at the open end of the mouth and neck to which the cap is attached, the inner surface (rear surface) of the top plate of the cap The sealing resin liner provided on the) side is brought into close contact with the curled part formed at the open end of the mouth-and-neck part.

  Specifically, for example, as shown in FIG. 7, a resin liner 38 having an inner annular portion 38 a, a central portion 38 b, and an outer annular portion 38 c is provided on the cap 3 on the inner surface side of the top plate portion 31. The curl portion 21a of the mouth / neck portion 21 is sandwiched between the inner annular portion 38a and the outer annular portion 38c while being pressed by the central portion 38b of the resin liner 38. When the foaming liquid containing carbon dioxide gas is used as the contents, a plurality of slits 33 are provided along the circumferential direction at the upper part of the skirt portion 32 of the cap 3 so as to form a vent hole. In order to open the can, when the cap is first loosened in the opening direction, the gas pressure in the can is first opened to the outside through the slit 33.

  In a can container equipped with such a cap 3, when the inner and outer surfaces of the can body are sterilized by spraying with a bactericide and drying with hot air, the resin liner 38 of the cap 3 is disposed on the inner surface side of the can body. It is difficult for a bactericidal agent or hot air to enter between the inner surface of the mouth and neck portion 21 (between the inner portion of the curl portion 21a and the inner annular portion 38a of the liner 38), and this portion may be insufficiently sterilized. On the other hand, on the outer surface side of the can body, the outer surface side of the mouth and neck portion 21 covered with the cap 3 cannot be sufficiently sterilized. When the slit 3 is formed in the cap 3, the bactericidal agent and hot air can be supplied to the outer surface side of the mouth and neck through the slit 33, but even in that case, the bactericidal agent and hot air are supplied through the narrow slit 33. Therefore, there is a possibility that sterilization may be insufficient or a bactericidal agent may remain on the outer surface side of the mouth / neck portion 21.

  An object of the present invention is to solve the above-described problems. Specifically, in an aseptic filling method using a can container that can be resealed by a cap, the inner and outer surfaces of the can body are sprayed with a disinfectant. When sterilizing by drying with hot air, it is an object to make it easy to sterilize the inner and outer surfaces of the mouth-and-neck portion to which the cap is attached without problems.

  In order to solve the above-described problems, the present invention uses a can container that can be resealed by a cap, and is open to an inverted can body with the can bottom side up in a substantially sterile atmosphere. In the aseptic filling method in which the contents are filled from the bottom of the can, the open end of the mouth and neck is sealed with a peelable seal lid from the can body whose mouth and neck are open. As a state, the inside and outside surfaces of the can body are sprayed with a sterilizing agent in a substantially aseptic atmosphere, the inside and outside surfaces of the can body are sterilized by drying and removing the sterilizing agent with hot air, and then the sterilized can body can After filling the sterilized contents from the bottom side and sealing the bottom of the can filled with the contents with a sterilized bottom lid, the mouth and neck of the can filled and sealed with the contents On the other hand, a cap is attached from above the seal lid.

  According to the aseptic filling method using the can container resealable by the cap of the present invention as described above, when the inner and outer surfaces of the can body whose can bottom side is opened are sterilized by spraying with a disinfectant and drying with hot air. In addition, the inner and outer surfaces of the mouth and neck can be easily and sufficiently sterilized without being obstructed by the cap. In addition, when filling the contents of the can body, the sealing on the mouth and neck side can be sufficiently secured by the seal lid even though the cap is not attached to the mouth and neck part. The contents can be efficiently filled from the opened can bottom side.

  In addition, since the mouth and neck are sealed with a sealing lid until the can is opened, even if the cap is opened while the can is inadvertently tilted at the time of opening, the liquid in the contents can be removed from the mouth and neck. There is no such thing as spilling out. In addition, only when resealing (resealing) after opening the can, the sealing performance and content resistance of the cap become a problem. Therefore, the cap and neck should be sealed with the cap from the beginning without providing a sealing lid. Compared to the case, it is possible to loosen the standard of sealing and content resistance, and to expand the options of the cap.

  In addition, if germs are mixed in the can with the contents filled and sealed, the internal pressure of the can may become abnormally high due to carbon dioxide generated by the germs. In contrast, if the cans filled and sealed with the contents are stocked for an appropriate period (for example, a few days) before the cap is attached, carbon dioxide due to various germs is generated during that period. Because the part of the seal lid swells rapidly, detecting the swelling of the seal lid with a displacement sensor or the like makes it possible to easily know the defective can mixed with various germs. By removing it, quality control of the product can be improved.

  About the aseptic filling method using can containers that can be resealed with caps, when the inner and outer surfaces of the can body are sterilized by spraying with a bactericidal agent and drying with hot air, the inner and outer surfaces of the mouth and neck to which the cap is attached can be easily As shown in the following embodiment as the best mode for the purpose of making it possible to sterilize without problems, the seal can be peeled off from the can body in which the mouth and neck side and the can bottom side are opened. With the open end of the mouth and neck sealed with a lid, spray the sterilizing agent on the inner and outer surfaces of the can body in an almost aseptic atmosphere, and dry and remove the sterilizing agent with hot air to sterilize the inner and outer surfaces of the can body. Then, after filling the sterilized contents from the can bottom side of the sterilized can body and sealing the can bottom side of the can body filled with the contents with the sterilized bottom lid, the contents are A cap is attached to the mouth and neck of the filled and sealed can from above the seal lid It was realized by the fact that that.

  As shown in FIG. 1, the can container used in the method of the present embodiment has a wide-mouth reseal can having a small difference in the diameter of the mouth-neck portion and the trunk portion and a relatively small shoulder portion (a modified bottle-shaped can). In the can container 1, the can neck (can body) 2 provided with the mouth / neck part 21, the shoulder part 22, and the body part 23 is made of metal in the mouth / neck part 21. The cap 3 that is a separate part is manufactured by roll-on molding using a known cap mounting device (capper) so that it can be resealed (resealed) by screwing. A bottom cover 4 made of metal and made of a separate part is integrally wound and fixed to the lower end by a known can lid winding device (seamer).

  About the aseptic filling method using such a can container, in the method of the present embodiment, the can body (can body excluding the cap and the bottom lid) in which the mouth neck side and the can bottom side are opened, The open end of the can and neck side is sealed with a peelable seal lid, and the can body is turned upside down with the can bottom side facing up and the neck and neck side facing down. After filling the contents, sealing the bottom of the can by tightening (double-winding) the bottom lid, filling and sealing the contents, and then against the mouth and neck of the can A cap is attached from above the seal lid.

  That is, in the can body before the contents are filled and sealed, as shown in FIG. 2, the mouth and neck portion 21 of the can body 2 is formed with an outer curled portion 21 a at the open end of the upper end, Below that, an inclined portion 21b whose diameter is reduced upward is formed, a screw portion 21c is formed on the lower peripheral wall, and an annular bead portion 21d is formed below the screw portion 21c. Moreover, although the lower end of the trunk | drum 23 of the can body 2 is neck-flange-processed and formed in the flange part 24, the bottom cover has not been fastened tightly yet, and the can bottom side is opened widely. It has been left.

  As shown in FIGS. 2 and 3, the seal lid 5 is heat-sealed on the tip portion of the mouth-and-neck portion 21 (the upper end surface and the outer surface of the curled portion 21 a). The opening end of the mouth-and-neck portion 21 is hermetically sealed by the seal lid 5. A peeling tab 5 a is formed on a part of the peripheral edge of the seal lid 5 so as to become a knob when the seal lid 5 is peeled off from the mouth / neck portion 21.

  For the can body (can body) of the can container, for example, a thin steel plate of about 0.3 mm in which a resin film such as polyethylene terephthalate having a thickness of about 12 μm is laminated on at least the inner surface side is welded into a cylindrical shape. , A can body manufactured from a welded can body in which at least the inner surface side of the welded portion is repair-painted with a resin such as polyethylene terephthalate, and a thin film in which a resin film such as polyethylene terephthalate is laminated on at least the inner surface side An appropriate can body such as a seamless can body in which a metal plate is formed into a cup shape by squeezing and ironing or the like, and then a mouth and neck portion of the can bottom side is formed is used.

  In addition, for a sealing lid that can be peeled off and attached to the tip of the mouth and neck of the can body, a single layer film of aluminum foil or oxygen such as aluminum foil or ethylene vinyl alcohol copolymer resin can be used. It consists of a laminated film such as a non-permeable material sandwiched with an olefin resin such as polypropylene or a polyethylene terephthalate resin, and is bonded to the mouth and neck of the can through an adhesive. It adheres flatly to the tip of the plate without slack.

  As the adhesive for adhering the seal lid, a heat-sensitive adhesive or a pressure-sensitive adhesive can be used, and its thickness is about 200 μm at the maximum. Examples of the heat sensitive adhesive include polyethylene terephthalate resin, polyvinyl ether resin, chlorinated polypropylene resin, and graft-modified polypropylene resin. Pressure sensitive adhesives include acrylic rubber resin, Isobutylene resin, polychloroprene resin, etc. can be used.

  In addition, when using a heat sensitive adhesive, a high sealing performance can be obtained by the strong adhesive force by the welding of the resin by the heat sealing method. On the other hand, when using a pressure-sensitive adhesive, the production speed can be increased by adhering the seal lid with the pressure when the cap is attached, compared to the case where the heat-sensitive adhesive is used and the heat-seal method is used. When opening the can, the sealing lid can be peeled off with a small force, and the opening operation can be easily performed.

  By the way, as shown in FIG. 2, the contents of the can body 2 in which the cap is not attached to the mouth / neck part 21 and the opening end of the mouth / neck part 21 is sealed by the seal lid 5 are aseptically filled. In the case of filling and sealing, in the method of the present embodiment, first, in the can body carrying-in process, the inner and outer surfaces of the can body are washed and dried in advance with a rinser, and then the can body is turned upside down to be substantially aseptic. It is carried in the atmosphere (clean booth).

  Then, as shown in FIG. 4, in a substantially aseptic atmosphere, the dust removal step (A), the inner surface sterilization step (B), the inner surface drying step (C), the seal lid cooling step (D), and the outer surface sterilization step (E). , Outer surface drying step (F), seal lid cooling step (G), contents filling step (H), nitrogen gas filling step (I), bottom lid winding step (J) After carrying out each process of the outer surface cleaning process (K) and the drying process (L) in a state where the can body is erected after being taken out from the inside, the mouth of the can body is opened in a cap mounting process (not shown). By attaching a cap to the neck from above the seal lid, as shown in FIG. 1, a canned product with a cap 3 is provided.

  About each said process, specifically, with respect to the can 2 sealed in the sealing lid 5 and carried in an approximately aseptic atmosphere in an inverted state, in the dust removing process (A), the can is made sterile through a filter. The dust inside the can body is removed by blowing aseptic air to the inside of the can body. Note that aseptic air containing dust is immediately sucked out of a substantially aseptic atmosphere and discharged. In the inner surface sterilization step (B), a hydrogen peroxide solution having a concentration of about 35% is heated to about 100 to 120 ° C. and sprayed toward the inner surface side of the can body. In the inner surface drying step (C), aseptic air heated to about 100 to 140 ° C. is blown toward the inner surface side of the can body, so that the excessively adhered to the inner surface side of the can body in the previous step. Hydrogen peroxide water is removed by evaporation.

  As for the can body whose inner surface side has been sterilized in such a manner, in the outer surface sterilization step (E), hydrogen peroxide water having a concentration of about 35% is heated to about 100 to 120 ° C. and directed toward the outer surface side of the can body. Spraying. In the outer surface drying step (F), aseptic air heated to about 100 to 140 ° C. is blown toward the outer surface side of the can body, so that the excessively adhered to the outer surface side of the can body in the previous step. Hydrogen peroxide water is removed by evaporation.

  In the method of this embodiment, the can body is transported with the seal lid not grounded (for example, the can body is transported by supporting the shoulder between the neck and neck of the can body with the retainer or holder). However, immediately after the inner surface drying step (C) and immediately after the outer surface drying step (F), a seal lid cooling step (D) and a seal lid cooling step (G) are provided, and aseptic air at room temperature is directed toward the seal lid. By spraying, the sealing lid is prevented from being softened. These sealing lid cooling processes are not essential, but because the sealing lid is softened by heated hydrogen peroxide or heated aseptic air, cooling by blowing normal temperature (low temperature) aseptic air, etc. It is desirable to prevent the sealing lid from being softened.

  Moreover, about the inner surface sterilization process (and inner surface drying process) and the outer surface sterilization process (and outer surface drying process), in the method of a present Example, the process of an inner surface side is implemented before the process of an outer surface side. As a result, the hydrogen peroxide solution adhering to the inner surface side of the can body is heated twice in both the inner surface step and the outer surface step, so that the hydrogen peroxide solution remains on the inner surface side of the can body. Such a fear disappears. On the other hand, when the process on the outer surface side is performed before the process on the inner surface side, the bacteria on the outer surface side move to the inner surface side during the transition to the inner surface side process after the outer surface side process ends. However, since the bacteria on the inner surface side are finally sterilized, the process on the outer surface side may be performed before the process on the inner surface side.

  Further, in the method of this example, the inner and outer surfaces of the can body were sequentially sterilized and dried in the state where the can body was inverted, but the can body was erected without being inverted, for example. In this state, the upper surface of the seal lid is sucked with a suction cup to suspend the can body. In this state, the inner and outer surfaces of the can body are simultaneously sterilized and dried, and then the can body is lowered onto the conveyor, Other methods such as sterilizing and drying the outer surface may be used.

  For cans whose inner and outer surfaces have been sterilized by spraying with a disinfectant (hydrogen peroxide solution) and drying with hot air (sterile air), in the contents filling step (H), the bottom of the can opposite to the seal lid The can body is turned upside down and the contents are filled from the opened can bottom side, and the can body filled with the contents is formed in the nitrogen gas filling step (I). Immediately after filling the head space with nitrogen gas, in the bottom lid winding process (J), a sterilized bottom lid is attached to the flange portion, which is the open end on the bottom side of the can body. The can body is sealed by double winding with a winding device.

  In the method of the present embodiment, the air in the head space of the can body is replaced with nitrogen gas in the nitrogen gas filling step (I), but this nitrogen gas filling step (I) is not essential, For example, if the content is an extracted beverage such as coffee, tea or green tea, the beverage after being extracted is still warm, or the beverage is warmed by instant heat sterilization and the beverage is heated in a sterilized can body Then, the can body is sealed with a sterilized bottom lid immediately after filling, so that the air in the head space may be replaced with the vapor of the beverage.

  The can body filled and sealed with the contents is taken out from the substantially aseptic atmosphere, and if necessary, the outer surface side of the can body is washed with tap water in the outer surface cleaning step (K), and the drying step (L ), The water adhering to the outer surface side of the can body is dried by hot air drying or natural drying, and then the cap and neck portion of the can body by a known capper (cap mounting device) in the cap mounting process (not shown). On the other hand, a cap is attached from above the seal lid. Note that. FIG. 5 and FIG. 6 show specific examples of the state in which the cap is mounted on the mouth and neck of the can body from above the seal lid.

  According to the aseptic filling method of the present embodiment according to each process as described above, the inner and outer surfaces of the can body whose can bottom side is opened in the inner surface sterilization step (and inner surface drying step) and the outer surface sterilization step (and outer surface drying step). Can be easily and sufficiently sprayed with a bactericide and dried with hot air on the inner and outer surfaces of the mouth and neck of the can body without being obstructed by the cap. The inner and outer surfaces can be reliably sterilized. In addition, when filling the contents in the contents filling step, the sealing ability on the mouth and neck side can be sufficiently secured by the seal lid even though the cap is not attached to the mouth and neck part. The contents can be efficiently filled from the opened can bottom side.

  Further, when opening the can, particularly in a can container having a relatively large diameter at the open end of the mouth and neck of the can body, such as the wide-mouthed reseal can used in the method of the present embodiment, there is no seal lid. With the conventional one, if the cap is opened carelessly while the can is tilted even when opened, the contents in the can may spill from the open end of the tilted neck and neck. According to the method of the embodiment, since the opening end of the mouth and neck portion is sealed with the sealing lid at the time of opening, even if the cap is opened with the can tilted at the time of opening, the contents in the can are still in the mouth and neck. There is no fear of spilling from the part.

  In addition, after opening the can by peeling off the seal lid, the can is resealed (resealed) with a cap. It is only necessary to consider the sealability and content resistance at the time of use, and it is not necessary to consider the sealability and content resistance at the time of storage, distribution and sale of the product. For example, when a sealing liner 38 is provided on the cap 3, as shown in FIG. 5, an inexpensive material liner is appropriately selected. It can be used, and in some cases, as shown in FIG. 6, the sealing liner may be omitted. For example, it is possible to widen the cap options by loosening the standard of sealing performance and content resistance. it can.

  Even if the inner and outer surfaces of the can body are completely sterilized by the inner surface sterilization step (and inner surface drying step) and the outer surface sterilization step (and outer surface drying step) in a substantially aseptic atmosphere, for example, in the sterilized contents Therefore, it cannot be said that the germs are never mixed in the can filled and sealed with the contents. And when miscellaneous bacteria mix in a can by any chance, the can internal pressure becomes high with the carbon dioxide gas generated by miscellaneous bacteria. On the other hand, in the method of the present invention, if a can filled and sealed with contents is stocked for a suitable period (for example, a few days) before the cap is attached, germs can be internally contained. In the can where the internal pressure of the can is increased due to the generation of carbon dioxide gas, the seal lid part immediately bulges out. By detecting the swelling of the seal lid with a displacement sensor, etc., it is easy to detect defective cans mixed with germs. As a result, defective cans caused by various germs in the can can be quickly removed to improve product quality control.

  As described above, one embodiment of the aseptic filling method using the can container which can be resealed by the cap of the present invention has been described. However, the method of the present invention is not limited to the above embodiment, Needless to say, it can be changed.

  That is, for example, the target can container is not limited to the wide-mouthed resealable can with a relatively small shoulder portion, and the mouth neck portion The bottle-shaped can with a general shape having a relatively large shoulder portion with a large difference in the diameter of the portion may be used, and the cap attached to the can body is also made of a metal as shown in the embodiment. 1 (in the metal cap shown in FIG. 1, a pilfer is formed with a slit serving as a vent hole in the upper part of the skirt part hanging from the outer edge of the top plate part, and the lower part of the skirt part can be separated. The cap is not limited to a proof ring, and may be a cap made of resin, or a cap having no pilfer proof function and no slit.

  In particular, in the can container used in the method of the present invention, even if the cap itself does not have a pill fur proof function, the opening end of the mouth and neck is sealed with a peelable seal lid. A pilfer proof function can be achieved by the presence or absence of peeling. In addition, since the inner and outer surfaces of the mouth and neck are sterilized without the cap attached, there is no need to provide the cap with a slit for passing a bactericide or hot air. As a result, by simplifying the structure of the cap or omitting the pilfer proof function, the cap can be reduced in weight, and the cost required for the cap can be reduced.

The side view which shows the wide mouth reseal can which is an example of the can container used for the method of this invention. The side view which shows the state of the can body before filling and sealing the contents with the can container shown in FIG. The partial expanded sectional view which expands and shows a part of mouth neck part of the can shown in FIG. Side surface explanatory drawing which shows each process of the aseptic filling method which concerns on one Example of the method of this invention. The partial expanded sectional view which expands and shows a part of mouth neck part and a cap about an example of the state with which the cap was mounted | worn with the mouth neck part of the can by the method of this invention. The partial expanded sectional view which expands and shows a part of mouth neck part and a cap about the other example of the state with which the cap was mounted | worn with the mouth neck part of the can by the method of this invention. The partial expanded sectional view which expands and shows a part of mouth neck part and a cap about an example of the state with which the cap was mounted | worn with the mouth neck part of the can by the conventional method.

Explanation of symbols

1 Can container 2 Can body (can body)
3 Cap 4 Bottom lid 5 Seal lid 21 Mouth and neck

Claims (1)

  An aseptic filling method that uses a can container that can be resealed with a cap to fill the contents from the opened bottom side of an inverted can body with the bottom side up in an almost aseptic atmosphere. The can body with the mouth and neck side and the bottom of the can opened on the inner and outer surfaces of the can body in a substantially aseptic atmosphere with the open end of the mouth and neck sealed with a peelable seal lid Spray the sterilizing agent, dry and remove the sterilizing agent with hot air, sterilize the inner and outer surfaces of the can body, fill the sterilized contents from the bottom of the sterilized can body, After sealing the bottom of the filled can with a sterilized bottom lid, attach a cap from above the seal lid to the mouth and neck of the can filled with the contents An aseptic filling method using a can container which can be resealed by a cap characterized by the above.

Images