JPH04242525A - Method and device for sterilizing container lid - Google Patents

Abstract

PURPOSE:To provide a method and device in which a container lid can be sterilized by irradiation with ultraviolet rays wholly, uniformly and effectively for a short time. CONSTITUTION:A substantially flat container lid is fed successively between a pair of ultraviolet-ray irradiators 3 provided opposingly up and down in the horizontal direction, while made to rotate if necessary, with its outer surface faced to an upper ultraviolet-ray irradiator and with its inner surface faced to a lower ultraviolet-ray irradiator. As a device for embodying this sterilizing method, a device comprising of an ultraviolet-ray irradiated zone B provided with a pair of ultraviolet-ray irradiators arranged opposingly up and down in the horizontal direction, and a transfer mechanism for transferring the container lid from a container lid holding zone to the ultraviolet-ray irradiated zone is employed. The transfer mechanism is additionally provided with another mechanism for feeding the container lid while giving rotation to it by relating a pusher 9 to a contact place of the container lid. Thereby this device is made a sterilizing device prominent in the sterilizing effect.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method and apparatus for sterilizing container lids such as can lids and bottle lids by UV irradiation.
More specifically, the present invention relates to a method and apparatus for sterilizing container lids, which makes it possible to uniformly sterilize both surfaces of a container lid by UV irradiation in a short time.

0002

[Prior Art] In the production of canned beverages, etc., the can body and can lid constituting the can container are sterilized in advance by UV irradiation, etc.
Means have traditionally been employed to ease the sterilization conditions for canned beverages by reducing the level of microorganisms originating from the can container. For example, Japanese Patent Publication No. 57-52062 discloses a device for sterilizing container lids by irradiating them with ultraviolet rays, in which a plurality of rotatable columns provided with screw grooves are provided, and containers are sterilized by the screw grooves between these columns. A device is disclosed in which lids are supported in a stacked manner and the container lids are sequentially conveyed downward by rotation of the pillars, and in this device, the container lids held between the pillars are transported from top to bottom. When being transferred to a storage room, ultraviolet rays are irradiated from the side to sterilize them.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned device, since the ultraviolet rays are irradiated from the side of the container lid, there is a large variation in the amount of ultraviolet rays irradiated between the central part and the peripheral part of the lid. This is unavoidable, and in order to effectively sterilize even the central part, it was necessary to lengthen the irradiation time with ultraviolet rays. This tendency is particularly noticeable in container lids such as aluminum pull top ends that have rivets or scores and have uneven surfaces. In addition, in ultraviolet sterilization, if UV irradiation is performed for a long time, the irradiated object may change in quality, discolor, or develop a strange odor (for example, a burnt odor). There is a problem in that the flavor of the contents of the can container is impaired, and from the viewpoint of the flavor of the contents, it is necessary to carry out sterilization treatment by ultraviolet irradiation efficiently and in a short time.

0004

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for sterilization using ultraviolet irradiation, which can uniformly and effectively sterilize the entire container lid by irradiating ultraviolet rays, and which can sterilize in a short period of time. It is about providing.

[0005]

[Means for achieving the object] According to the present invention, a substantially flat container lid is continuously supplied between a pair of ultraviolet ray irradiation devices provided vertically and horizontally opposite each other, and In the method of sterilizing the container lid by irradiation, the container lid is continuously supplied such that the outer surface thereof faces the upper ultraviolet irradiation device and the inner surface faces the lower ultraviolet irradiation device. A method for sterilizing container lids is provided.

Further, according to the present invention, there is provided a container lid holding area consisting of a plurality of rotatable columns provided with screw grooves, and an ultraviolet irradiation device comprising a pair of ultraviolet irradiation devices disposed vertically and horizontally opposite each other. a transport mechanism for transporting the container lid from the container lid holding area to the ultraviolet irradiation area, the substantially flat container lid is supported by the plurality of pillars, and is moved upwardly by rotation of the pillars. The container lid located at the lower end of the container lid is transported downward from the container lid by the transport mechanism so that its outer surface faces the ultraviolet irradiation device located above,
Further, there is provided a sterilizer in which UV irradiation is continuously supplied to the UV irradiation area so that the inner surface faces the UV irradiation device below, and sterilization is performed by UV irradiation on both sides of the container lid, and the transport mechanism of this sterilizer includes: By providing a mechanism that imparts rotation to the container lid while being conveyed in the traveling direction by a rotatable pusher in which the center of the pusher is eccentric in a direction perpendicular to the center of the container lid and the advancing direction of the pusher and comes into contact with the container lid. , more uniform container lid sterilization is achieved.

[0007] In other words, in the conventional sterilization method, ultraviolet rays were irradiated from the side of the container lid.
In the present invention, the container lid is continuously transported so that the outer surface and the lower surface of the container lid are irradiated with ultraviolet rays at the same time, and this transportation is accompanied by rotation of the container lid.
The variation in the amount of ultraviolet irradiation between the center and peripheral parts of the container lid is effectively corrected, making it possible to uniformly sterilize the entire container lid, and as is clear from the examples described later, it is possible to sterilize the entire container lid in an extremely short period of time. Since sterilization is effectively performed by UV irradiation over a period of time, not only is the work efficiency excellent, but problems such as deterioration, discoloration, and generation of odor of the lid material are effectively prevented.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described in detail based on specific examples shown in the accompanying drawings. 1 and 2 showing a side view and a plan view of an apparatus that can suitably carry out the sterilization method of the present invention, the apparatus generally includes a container lid holding area A, an ultraviolet irradiation area B, and a container lid transporting area. It consists of mechanism C. The container lid holding area A is for holding substantially flat plate-shaped (generally disc-shaped) container lids created in a separate process in a stacked state. Three pillars 1 each having a screw groove are rotatably provided in this holding area A, and container lids 2 are stacked between these pillars 1 in a positional relationship that engages with the screw grooves. ing. That is, the rotation of the support column 1 causes each container lid 2 to move from above to below. In this container lid holding area A, in order to perform sterilization by ultraviolet rays in the next step more effectively and in a short time, for example, the outer periphery 12 below the container lid holding area A is heated by high frequency induction heating.
It can be preheated at 100° C. or less for about 5 seconds or less.

The ultraviolet irradiation area B is equipped with an ultraviolet irradiation device 3 consisting of an ultraviolet irradiation lamp, and two ultraviolet irradiation devices 3 are provided vertically facing each other. That is, as is clear from FIG. 1, when the container lid 2 passes between the two ultraviolet irradiation devices 3, the container lid 2 is irradiated with ultraviolet rays and sterilized. In general, it is preferable that the irradiation dose of ultraviolet rays at this time be 20 mW·sec/cm 2 or more.

[0010] The container lid conveyance mechanism C has the container lid holding area A.
The container lid 2 is transferred from the ultraviolet irradiation area B to the ultraviolet irradiation area B, and is passed between two ultraviolet irradiation devices 3. This container lid conveyance mechanism C is connected to a
It consists of a pair of cover guides 4 extending between two ultraviolet irradiation devices 3, and a sprocket conveyor 5 provided on one cover guide 4 side. In this sprocket conveyor 5, a chain 8 is stretched between a drive roller 6 and a drive roller 7, and the chain 8 is provided with attachments 10 having pushers 9 at the tips at predetermined intervals. There is. That is, the pillar 1
The container lid 2 located at the lower end of the container lid 2 is transferred between the two ultraviolet irradiation devices 3 via a pusher 9 by an attachment 10 driven by the chain 8. As shown in FIG. 2, the container lid 2 to be transferred is held at both ends by a cover guide 4, and is sterilized sequentially by ultraviolet irradiation from above and below during the transfer. It has become.

[0011] The above description has been made of the case where the pusher 9 contacts the center line of the container lid as shown in FIG. The object is to be conveyed between the ultraviolet irradiation devices 3 while rotating.

FIG. 3 is a partially enlarged plan view of the sterilizer equipped with a transport mechanism for transporting the container lid between the ultraviolet irradiation devices 3 while rotating, and FIG. 4 is a sectional view of the same side. The biggest technical feature is that the center of the pusher 9 is offset in a direction perpendicular to the center of the container lid 2 and the direction of movement of the pusher, and is conveyed in the direction of travel by a rotatable pusher that comes into contact with the container lid. The point is that it is equipped with a mechanism that provides rotation.

FIG. 5 is a partially enlarged plan view of the sterilizer for explaining the principle of rotation of the container lid. As shown in FIG. 5, since the center of the pusher is eccentric in the direction perpendicular to the center of the container lid and the direction of movement of the pusher, the pusher in contact with the container lid generates a force Fv. In addition, the force of the pusher causes the container lid to be pressed against one of the guide rails, causing a frictional force Ff and a reaction force f from the guide rail to the container lid. Due to the force FH generated in the traveling direction from the contact part, the pusher moves clockwise and the container lid counterclockwise (when the pusher is in contact with the container lid below the center line) while rotating. .

Explanation of symbols in FIG. 5 F: Force acting on the lid from the pusher FH: Horizontal component of force F (force to move the lid along the guide) Fv: Vertical component of force F f: Due to force Fv The reaction force generated on the guide and container lid (f
=-Fv) Ff: Frictional force caused by contact between the guide and the container lid Ff=
μf (μ; dynamic friction coefficient)

[0015] Thus, by providing a mechanism for imparting rotation to the container lid while being transported in the traveling direction by the transport mechanism, more uniform sterilization of the container lid can be achieved, and after sterilization, the container lid 2 The liquid is discharged into a cover chute 11 provided on the opposite side from the container lid holding area A, and stored in a stacked state.

[0016]

According to the present invention, since the container lid is transported while simultaneously and uniformly irradiating the outer and inner surfaces of the container lid with ultraviolet rays, the time required to sterilize the container is approximately 1/10 of that of conventionally known ultraviolet sterilizers. Since sterilization can be carried out effectively and uniformly, and sterilization is carried out in a short period of time, problems such as deterioration, discoloration, and generation of strange odors such as burnt odor can be effectively avoided, and the flavor of the contents of the container can be effectively retained. A method and apparatus for sterilizing container lids are provided.

[0017]

[Example] Example 1, Comparative Example 1 Can lid (200P aluminum end) Heat-resistant bacteria (B.
Samples were prepared by applying a spore suspension of 1000 and 100 bacteria per can lid. Using the apparatus shown in FIGS. 1 and 2, the can lid sample was sterilized by irradiating it with ultraviolet rays for a certain period of time (Example 1). Furthermore, for comparison, an ultraviolet irradiation lamp was installed around the container lid holding area A of the apparatus shown in the above drawing, and the can lid sample held in this area was irradiated with ultraviolet rays from the side for a certain period of time to sterilize it. (Comparative Example 1). A sterilized empty can was aseptically filled with a sterilized meat extract medium, and the can lid sample sterilized above was rolled up and sealed. After storing this can in a constant temperature room at 37° C. for 5 days, the can was opened, and the presence or absence of deterioration was determined based on turbidity, odor, and pH. The results are shown in Table 1.

[0018]

[Table 1]

Example 2, Comparative Example 2 Using the sterilizer used in Example 1 and Comparative Example 1,
2D (reduces the number of bacteria by 2 digits), 3D (reduces the number of bacteria by 3 digits)
We irradiated them with the ultraviolet rays necessary for sterilization, and sensually evaluated the burnt odor that was generated. The results are shown in Table 2.

[0020]

[Table 2]

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a can lid sterilization device of the present invention.

FIG. 2 is a plan view of the sterilizer of FIG. 1;

FIG. 3 is a partially enlarged plan view of the conveyance mechanism in the can lid sterilization apparatus of the present invention.

FIG. 4 is a side sectional view of FIG. 3;

FIG. 5 is a partially enlarged plan view for explaining the principle of rotation of a container lid in the can lid sterilization device of the present invention.

[Explanation of sign]

A Container lid holding area B. Ultraviolet irradiation area C Container lid transport mechanism 2 Container lid 3. Ultraviolet irradiation device 4 Cover guide 5 Sprocket conveyor 6 Drive roller 7 Drive roller 9 Pusher 10 Attachment 11 Cover shoot 12 Preheating area

Claims (3)

[Claims] 1. A method of sterilizing container lids by continuously supplying substantially flat container lids between a pair of ultraviolet ray irradiation devices installed vertically and horizontally opposite each other, and sterilizing the container lids by irradiating them with ultraviolet rays. A method for sterilizing container lids, characterized in that the container lids are continuously supplied so that the outer surface thereof faces an upper ultraviolet irradiation device and the inner surface faces a lower ultraviolet irradiation device. 2. A container lid holding area consisting of a plurality of rotatable columns provided with screw grooves, an ultraviolet irradiation area comprising a pair of ultraviolet irradiation devices provided vertically and horizontally opposite each other, and the container lid. A transport mechanism for transporting the container lid from the holding area to the ultraviolet irradiation area, wherein the substantially flat container lid is supported by the plurality of pillars and is transported from above to below by rotation of the pillars. At the same time, the container lid located at the lower end is continuously moved into the ultraviolet irradiation area by the transport mechanism so that its outer surface faces the ultraviolet irradiation device above and the inner surface faces the ultraviolet irradiation device below. A sterilizer that sterilizes both sides of a container lid simultaneously and uniformly by irradiating ultraviolet rays. 3. The conveying mechanism is configured to move the container lid while being conveyed in the traveling direction by a rotatable pusher in which the center of the pusher contacts the container lid eccentrically in a direction perpendicular to the center of the container lid and the traveling direction of the pusher. The sterilizer according to claim 2, further comprising a mechanism for applying rotation to the sterilizer.