GB2115767A - Apparatus and method for aseptically filling flexible containers - Google Patents

Abstract

An apparatus for aseptically filling premanufactured, presterilized, flexible containers, connected in a continuous web, includes an elongate chamber with an inlet 20 for receiving empty containers seriatim, and an outlet 21 for dispensing filled containers seriatim. The inlet and outlet have respective flexible seals 64; 66, 67 for sealing to the surface of the containers and chamber is segregated into an entry chamber 70 and a filling chamber 68, with a drying chamber 72 therebetween. The containers pass through a liquid lock 62 between the entry and drying chambers to coat the exterior of the containers with the sterilizing agent as they are serially advanced through the chambers. This liquid lock also provides an aseptic barrier between the inlet and the drying chamber. A source of sterile air is input to the filling chamber 68 to maintain a positive pressure therein, and thus, prevent entry of contaminants. This heated sterile air flows from the filling chamber 68 to the drying chamber 72 to dry the containers after they have been coated with the sterilizing agent. The length of time the empty containers are exposed to the atmosphere, and thus, the amount of contamination on the exterior of the containers is reduced by connecting the sealed overwrap bag 120, in which the containers are presterilized, to the inlet 20, thus forming a relatively sterile tunnel through which the containers are fed to the inlet. <IMAGE>

Description

SPECIFICATION Apparatus and method for aseptically filling flexible containers The present invention relates to an apparatus and method for filling flexible containers in an aspectic environment. This invention is an improvement on the invention disclosed in copending Patent Application No. PCT/US 8100614, filed under the PCT on May 7, 1981, assigned to the assignee of the present invention.

Flexible bags, comprised of a plastics material, such as polyethylene, are well suited as containers for fluid substances, such as milk, water, fruit juices, wine, and chemicals. Typically, a spout is provided, through which the container may be filled and the contents may be dispensed.

The containers may be connected in continuous web form and filled by advancing the web of containers seriatim into a filling station, as described in US Patent No.4,120,134, issued on October 17, 1978 to William R. Scholle, and assigned to Scholle Corporation. The specification of that patent provides useful information helpful in understanding the context in which the present invention operates, and therefore, attention to that patent is hereby directed.

The apparatus described in US Patent No.

4,120,134 includes (a) feed means comprising conveyors for directing the continuous web, formed by the interconnected containers, from a supply carton onto a platform adjacent the filling station; (b) guide members for aligning the filling spout of each container as it moves along the plafform; (c) a mechanism for uncapping, filling, and recapping each container at the filling station; and recapping each container at the filling station; and (d) means for releasing the filling spouts after each container is filled. As described in the latter patent, the containers may be advanced either by a mechanically driven conveyor or an inclined passive conveyor. The passive conveyor utilizes the gravitational force of the filled containers on an inclined unloading conveyor to pull the web of empty interconnected containers behind it.

Where the contents of the containers are consumable, measures must be taken to ensure that such contents are free from contamination. If, for example, the containers are filled with high acid foods, it is necessary that the filling be performed under at least sanitary conditions.

However, where low acid or neutral pH foods, such as milk, are involved, it is desirable that the filling be performed under aseptic conditions, since this permits such foods to have a long shelf life than would otherwise be possible.

It is an object of the present invention to provide an apparatus and method which are an improvement on the known techniques.

The present invention provides an apparatus and method for filling flexible containers in an aseptic environment. This apparatus comprises a tunnel-like, elongate chamber having an inlet mouth with an entry port, through which the empty containers are fed, and a dispensing port, through which the filled containers are dispensed.

The elongate chamber is segregated into three sub-chambers, including an entry chamber, adjacent to the entry port, a filling chamber, adjacent to the dispensing port, and a drying chamber, interposed between the filling and entry chambers. A liquid lock separates the entry chamber from the drying chamber. In addition, the entry and dispensing ports each have a seal, formed of elastomeric material with a slit therein, to reduce the risk of contaminant migration into the elongate chamber while permitting the containers to pass therethrough. A supply of sterilized air is continuously input to the filling chamber to pressurize the drying and filling chambers and provide a flow of sterile air therethrough to prevent entry of contaminants and to maintain these chambers in an aseptic condition.

The present invention utilizes premanufactured containers, connected in a continuous web, which have been prepackaged in a sealed overwrap container and presterilized therein. The sealed overwrap container, which comprises, for example, a plastics bag, is positioned adjacent to the entry port. However, before opening the overwrap, it is preferable to apply a positive pressure within the overwrap container by introducing sterile air therein. This may be accomplished by providing a probe, connected to a source of sterilized air, which is used to puncture the wall of the overwrap and inflate the overwrap container. An opening is then formed in the overwrap container, as by slitting with a knife, to provide access to one end of the continuous web of containers packaged therein.An operator manually grasps the end of the continuous web, pulls it through the opening, and operably connects it to the feed means of the apparatus, for example, by clipping the leading edge of this continuous web to the trailing edge of the preceding continuous web of containers.

While some contaminants may enter the overwrap container during this operation, it will be recognized that the continuous flow of sterile air from the probe through the overwrap container tends to reduce such contamination. After the continuous web of containers has been operably connected to feed through the elongated chamber, the peripheral edges formed by the opening in the overwrap are sealed to the inlet mouth, as by a resilient band. The air supply to the overwrap container may then be decreased or discontinued, however it is preferable to provide sufficient air to maintain the overwrap bag in an inflated condition. In the foregoing manner, the overwrap bag and the inlet mouth provide a relatively sterile tunnel or semi-sterile environment which reduces the bio-load on the containers as they are fed into the apparatus.As used herein, the terms "semi-sterile" or "semiaseptic" mean an environment having a substantially reduce bio-load compared to the bio-load of the ambient environment, but a greater bio-load than required for aseptic filling of the containers.

In a preferred embodiment as the continuous web of containers is serially advanced into the elongate chamber, through the entry port, they initially pass through the entry chamber, where they enter a liquid lock, filled with a sterile fluid such as hydrogen peroxide. The liquid lock comprises a reservoir with a solid partition extending therein to seal the inlet mouth from the remainder of the elongate chamber. The partition separates the semi-aseptic entry chamber from the aseptic drying chamber and filling chamber. Idler rollers are provided to guide the web of containers from the inlet mouth into the reservoir, beneath the partition, and out of the reservoir, into the drying chamber.This coats the containers with hydrogen peroxide to resterilize the outside of the containers, and, thus, remove any contamination that may have occurred during the period when the overwrap container was open to the atmosphere. The inside of the containers are not resterilized, since the containers are sealed with caps on their respective spouts, thereby preventing entry of contamination. These caps also prevent the hydrogen peroxide from contacting the interior product contact surfaces of the containers.

As the containers are fu'rther advanced seriatim through the elongate chamber, they pass from the liquid lock to the drying chamber, where the hydrogen peroxide coating is evaporated by a flow of heated, sterile air. The heated air heats the hydrogen peroxide sterilizing agent and enhances its effectiveness in sterilizing the containers.

Further serial advancement of the containers moves them from the drying chamber to the filling chamber where the spout caps are removed, the containers filled with a food substance, and the spout caps replaced. The filled containers are then advanced out of the filling chamber through the seal in the dispensing chamber, and onto the inclined conveyor. A severing bar disconnects adjacent filled containers at perforations in the container web between adjacent containers, so that the containers may be deposited into protective enclosures, such as cardboard boxes.

At all times during the foregoing process, the filling chamber is maintained at a positive pressure, by inputting, as discussed above, sterile air therein to prevent entry of contaminants. This sterile air flows from the filling chamber to the drying chamber, and thus, also serves to maintain the drying chamber at a positive pressure. Further, the liquid lock between the entry and drying chambers provides an aseptic barrier between the drying chamber and the semi-aseptic chamber.

Thus, the filling chamber is constantly maintained in an aseptic condition as the containers are serially advanced therethrough.

The present invention, therefore, provides an aseptic environment for filling premanufactured, prepackaged, and presterilized, flexible containers, connected in continuous web form.

Further, by providing a semi-sterile environment, utilizing the overwrap bag to form a tunnel, the microorganism population on the containers is reduced, thereby reducing the sterilant exposure time and temperature levels necessary to yield an adequate "kill" of the microorganisms.

The invention is further hereinafter, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of an aseptic filling apparatus in accordance with the present invention showing the elongate chamber receiving a continuous web of flexible bags through an inlet mouth, and dispensing the containers through an outlet mouth and onto the inclined conveyor, after the containers have been filled by the filling nozzle; Figure 2 is a partial perspective view of the sterile chamber of Figure 1; Figure 3 is a schematic drawing of the elongate chamber of Figure 1 showing the entry chamber liquid lock, drying chamber, and filling chamber; Figure 4 is a fragmentary, perspective view of the elongate chamber of Figure 1, showing the configuration of the partition between the drying chamber and filling chamber; and further showing the tube which provides a vent for the sterile air flow through the elongate chamber; Figure 5 is a fragmentary perspective view of the containers being received into the chamber through the inlet mouth, showing the elastomeric seal sealing to the exterior of the containers; Figure 6 is a fragmentary perspective view of the filled containers being dispensed through the outlet mouth, showing the elastomeric seals sealing to the exterior of the filled containers; Figure 7 is a series of perspective views illustrating a method of packaging the continuous web of containers for sterilization;; Figure 8 is a series of perspective views illustrating a method of opening the container overwrap bag to reduce contaminant entry through the opening, and showing a method of sealing this bag opening to the inlet mouth of the chamber to form a relatively sterile tunnel for the containers; and Figure 9 is a fragmentary side elevation, in partial cross-section, showing the liquid lock for coating the containers with the sterilizing agent.

Referring to Figure 1, the illustrated aseptic filling apparatus 10 includes a skeletal support frame 12 formed by plural upstanding posts 14 interconnected by plural cross members 1 6.

The support frame 12 mounts an elongate chamber 18, having an inlet mouth 19, which forms an entry port 20 at one end of the chamber 18, and an outlet mouth 21, which forms a dispensing port 22 at the opposite end of the chamber 18, as shown in Figures 1 and 2. A continuous web of containers 24, having respective spouts 25, are fed seriatim into the entry port 20. Container support rollers 23 (Figure 2), horizontally mounted between the sides of the chamber 1 8, provide support for the containers 24 as they are advanced through the elongate chamber 18 by a passive, inclined conveyor 26, as described in US Patent No. 4,120,134, issued on October 1 7, 1978, to William R. Scholle, and designed to Scholle Corporation, and to which reference is hereby directed.Alternatively, the containers 24 may be advanced through the elongate chamber 18 by the mechanically driven mechanisms described in US Patent No.

4,120,134 or in co-pending patent application Serial No. Unknown, attorney Docket No. 5009-A, entitled "Container Conveyor For a Flexible Container Filling Machine", filed March 19, 1981, by Roger H. Ellert.

As shown in Figures 1 and 2, a filling nozzle 30, for filling the containers 24, extends through, and is sealed to, the top of the elongate chamber 18, near its dispensing end. When a container spout 25 reaches a position beneath this nozzle 30, it is uncapped, filled by the nozzle 30, and recapped.

The nozzle 30 is connected to a flow controller 34, mounted on the frame 12, which dispenses measured amounts of product, such as a food substance, through the spout 25 and into the container 24. After the container spout 25 has been uncapped, and the container 24 has been filled by the nozzle 30, a vertical post 36 is advanced upward to cause the lower wall of the container 24 to seal off the container spout 25 prior to capping to prevent entry of air into the filled container 24. Further details of this filling mechanism, as well as a capping mechanism for uncapping and recapping the spouts 25, are provided in the above-referenced US Patent No.

4,120,134.

After filling, the containers 24 are advanced through the dispensing port 22 and onto the inclined conveyor 26. This inclined conveyor 26 comprises plural idle rollers 40 connected between opposing side frames 42, 44. The side frames 42, 44 are rotatably connected at one end to respective brackets 46 connected to a cross member 16 of the support frame 12. The brackets 46 are positioned to permit the conveyor 26 to receive filled containers 24 from the dispensing port 22. The end of the inclined conveyor opposite the dispensing port 22 is supported by a post 50, which may be telescopingly adjusted to vary the angle of inclination of the inclined conveyor 26. A container separator 52 having a severing bar 54 is connected to the side frames of the conveyor 26.This separator 52 serves to disconnect adjacent filled containers 24 at perforations, preformed in the container web between adjacent containers 24, so that the containers 24 may be deposited into protective enclosures, such as cardboard boxes.

The chamber 18 As best seen in Figure 3, the elongate chamber 18 is divided into a filling chamber 68, an entry chamber 70, and a drying chamber 72. The drying chamber 72 and the filling chamber 68 are separated by a partition 60, oriented perpendicularly to the longitudinal axis of the chamber 18. The filling chamber 68 is bounded by the outlet mouth 21 on one end and the partition 60 on the other end. The filling nozzle 30 projects into this chamber 68. A liquid lock 62 is located between the entry chamber 70 and the drying chamber 72. The drying chamber 72, is bounded by the partitions 60 on one side and the liquid lock 62 on the other.

An elastomeric seal 64 is provided across the inlet mouth 19 to seal the entry port 20. The outlet mouth 21 is provided with two elastomeric seals 66, 67, in spaced, parallel relationship, to form a double seal across the dispensing port 22.

The partition 60, and seals 64, 66, 67, all have an opening, described in detail below, to permit passage of the continuous web of containers 24 through the chamber 18.

Referring again to Figures 1 and 2, a source of sterile, heated air 76 is connected by tubing (not shown) to an inlet tube 78 in the filling chamber 68 (Figure 2) of the elongate chamber 18. The chamber 18 also has plural spray heads 80, 82, 84, 86 connected thereto, which are positioned to spray the compartments 72, 68, and mouth 21.

Each of these spray heads 80, 82, 84, 86 is connected by tubing (not shown) to the sterile air supply 76 and to a sterilant supply 88 containing, for example, a 30 percent solution of hydrogen peroxide in water. The spray heads 80, 82, 84, 86 atomize the hydrogen peroxide solution into a fine mist or fog, and spray such mist into the drying chamber 72, filling chamber 68, and dispensing mouth 21.

Sterilizing the chamber 18 Prior to utilizing the aseptic filling apparatus 10 of the present invention, the elongate chamber 18, as well as the product contact surfaces, should be sterilized to ensure that filling is performed in an aseptic environment. This is accomplished by spraying the above-described hydrogen peroxide solution through each of the spray heads 80, 82, 84, 86 simultaneously, to sterilize the elongate chamber 1 8. Sterile air is then supplied from the air source 76 to the inlet tube 78 to maintain the filling chamber 68 at a positive pressure, and thus, in an aseptic condition. As will be described in more detail below, this sterile air flow also maintains the drying chamber 72 and dispensing mouth 21 at a positive pressure, and, therefore, also in an aseptic condition.Once the sterile air flow to the filling chamber 68 has been started, the spray heads 80, 82, 84, 86 are shut off.

It will be understood that the product contact surfaces, such as the interior surface of the filling nozzle 30, are also sterilized prior to use of the apparatus 10. This is accomplished in a manner well known to those skilled in the art, for example, by steam sterilization techniques.

Controllers 92 monitor, record, and control the above-described processes and continually regulate flow rate, pressure, and temperature variables, such as the source temperature of the sterilized air, the air pressure in the filling chamber 68, the temperature of the airflow through the drying chamber 72, and the temperature of the steam for sterilizing the product contact surfaces. Windows 95 are provided in the side of the chamber 18 for viewing the operation of the apparatus 1 0.

The partition 60 and seals 64, 66, 67 of the chamber 18 Before turning to the operation of the container filling apparatus 10, the partition 60 and the seals 64, 66, 67, shown in Figure 3, will be described in more detail. Referring to Figure 4, the partition 60 includes an opening 106, sized to permit the continuous web of containers 24 to pass therethrough. The contour of the opening 106 is generally rectangular with a notch 107 formed along its upper edge to accommodate the filling spouts 25 of the containers 24. The opening 106 should be large enough to permit the previously described flow of sterile air through the inlet tube 78 (Figure 2) to pass from the filling chamber 68, through the opening 106, and into the drying chamber 72.However, it should be sufficiently small to permit the filling chamber 68 to be at a slightly higher pressure than the drying chamber 72 to prevent flow of air from the drying chamber 72 to the filling chamber 68. A vent tube 108 is included in the bottom of the drying chamber 72, adjacent to the liquid lock 62, to provide an outlet for the sterile air after it has travelled through the chamber 72. This sterile air flow also prevents contaminants from entering the chamber 72 through the vent tube 108.

Referring to Figure 5, the entry port seal 64 is formed from an elastomeric material, such a dental dam, and includes a horizontal slit 114, slightly greater in length than the width of the continuous web of containers 24 to permit such containers 24 to pass therethrough. Thus, the edges of the slit 114 seal to the outer surface of the empty containers 24 to reduce contaminent entry into the chamber 1 8. The dispensing port seals 66, 67, shown in Figure 6, are identical to the entry port seal 64, except that they have respective slits 11 6 sized to permit filled containers 24 to pass therethrough. Like the slit 114, the slits 11 6 are elastomeric so that they (a) expand to permit passage of the containers 24, and (b) seal to the outer surface of the containers 24.Thus, the seals 66, 67, together with the positive pressure in the filling chamber 68, provide a barrier against contaminant entry through the mouth 21 and into the filling chamber 68.

The flexible containers 24 The aseptic filling apparatus 10 of the present invention utilizes containers 24 which are prepackaged in a sterile container. Although such prepackaging of the containers 24 is known in the art, a description of the packaging process may be useful in full understanding the operation of the present invention. Referring to Figure 7, the flexible containers 24 are premanufactured in continuous web form, precapped, and folded at perforations between adjacent containers, in an accordian fashion. The folded containers 24 are then placed in a sealed overwrap container 120, comprising, for example, a plastic bag. Preferably, this overwrap bar 120 is substantially greater in height than the height of the folded containers 24. Air is evacuated from the overwrap bag 120, and the overwrap bag 120, with the containers 24 therein, is placed in a shipping carton 122.The shipping carton 122 is then sealed and placed in a sterilizer (not shown) to sterilize the containers 24. Such sterilization may be accomplished in a conventional manner, such as by radiation.

Operation of the aseptic filling apparatus 10 During operation of the aseptic filling apparatus 10, the precapped, premanufactured, prepackaged, and presterilized containers 24 are fed into the elongate chamber 18 in the manner described below. The carton 122 is opened, and a probe 126, connected by tubing (not shown) to the sterile air source 76 (Figure 1), is inserted through the wall of the sealed overwrap bag 120, as shown in Figure 8, thereby causing the flow of sterile air through the probe 126 to inflate the sealed overwrap bag 120. An opening 128 is then formed in the overwrap bag 120, as by slitting with a knife (not shown). Preferably, the length of this opening 1 28 is slightly larger than the width of the web of containers 24 to permit an operator to manually grasp the end of the web of containers 24 and pull it through the opening 128.The operator then connects the leading edge of the web of containers from the overwrap bag 120 to the trailing edge 132 of the web of containers 24 which have been previously fed through the chamber 18. Such connection may be made by a pair of clips 134. It will be recognized that, although the opening 128 exposes the contents of the overwrap container 120 to the atmosphere, and thus to contaminants, the supply of sterile air through the probe 126 will provide an air flow through the opening 128 to reduce such contamination.

Further, use of the sterile air probe 126 to inflate the bag 1 20 prevents air from being sucked into the bag while it is being manipulated.

The peripheral edges formed by the opening 128 are then fitted around the inlet mouth 19 and attached thereto, as by a resilient, elastomeric band 136, to seal the opening 128 to the entry port 20. Thus, the overwrap bag 120, together with the entry chamber 70, provides a relatively sterile, aseptic tunnel for Dassage of containers 24 from the carton 122 to the liquid lock 62. The supply of sterile air through the probe 126 may then be reduced or discontinued, however, it may be desirable to provide sufficient air pressure to maintain the bag 120 in an inflated condition.

The containers 24 are then serially advanced through the chamber 18 by the feed means, previously discussed with reference to US Patent No. 4,120,134. Referring again to Figure 3, as the containers 24 pass through the entry port seal 64, and into the entry chamber 70, they are guided through the liquid lock 62 to coat the exterior of the containers 24 to kill any microorganisms that may have contaminated the containers 24 as a result of opening the overwrap bag 120 and exposing of the containers 24 to the atmosphere.

In this regard, the rate of advancement of the containers 24 through the chamber 1 8 is dependent upon the degree of contamination or "bio-load" on the exterior surfaces of the containers 24, and thus, this rate is regulated accordingly. However, it will be recognized that the above-described process of using the overwrap bag to form a tunnel-like enclosure reduces the amount of time that the containers 24 are exposed to the atmosphere, and therefore, advantageously reduces the bio-load on such containers 24. Consequently, because of this reduced bio-load, the required exposure time of the containers 24 to the hydrogen peroxide is reduced, thereby permitting more rapid advancement of the containers 24.It will also be understood that the interior surfaces of the containers 24 need not be resterilized, since their spouts 25 are capped to prevent contaminants from entering the containers 24.

The containers 24 are then advanced from the liquid lock 62, aimed into the drying chamber 72 where the hydrogen peroxide coating thereon is dryed by the flow of heated sterile air. As previously mentioned, this flow of heated sterile air travels from the opening 106 in the partition 60 through the drying chamber 72 and out of the vent pipe 108. Heating of the hydrogen peroxide coating, as is well known, enhances its antiseptic properties, and thus, ensures that the exterior surfaces of the containers 24 are aseptic when they enter the filling chamber 68. The temperature of this air should be sufficient to heat the hydrogen peroxide coating without damaging the plastic containers 24.Such temperature should preferably be in the range of 1 500F to 1900 F, since, higher temperatures may damage the containers, while lower temperatures may not be sufficient to sterilize the containers. In any case, the reduced bio-load provided by forming the sterile tunnel, as described above, permits use of lower temperatures then would otherwise be required. If needed, contact heaters (not shown) may be attached to the bottom of the drying chamber to boost temperatures and reduce temperature differentials in the drying chamber 72.

Since the supply of sterile air through the inlet tube 78 (Figure 2) maintains the filling compartment 68 in an aseptic condition, the sterilized containers 24 will remain sterile during filling. After the containers 124 have been filled, they are carried by the support rollers 23, through the dispensing port seal 66, and onto the inclined conveyor 26 where the container separator 52 (Figure 1) separates the containers 24 for packaging.

The liquid lock 62 Referring to Figure 9, the liquid lock 62 is comprised of a tub or reservoir 132, formed in the elongate chamber 18, between the inlet mouth 19 and chamber 72. The reservoir 132 is filled with a sterilizing agent, such as hydrogen peroxide, to a level slightly below the inlet mouth 19 and chamber 72, as seen in Figure 9. First and second idler rollers, 134, 136, are mounted adjacent the inlet mouth 1 9 and chamber 72, respectively, above the fluid level of the sterilant.

A third idler roller 138 is mounted in the reservoir 132, beneath the fluid level. A generally vertical, solid partition 1 40 is provided between the rollers 1 34, 1 36. This partition extends partially into the reservoir 132, below the liquid level, but above the roller 138, to provide a seal for preventing air from passing between the inlet mouth 19 and chamber 72. Thus, the partition 140 divides the elongate chamber 1 8 into a semi-aseptic section, which, viewed from Figure 9, is the portion of the chamber to the left of the partition 140 and an aseptic section, which is the portion of the chamber to the right of the partition.The web of containers 24 is threaded around the three idler rollers 134,136,138 so that they guide the containers from the inlet mouth 19, into the reservoir 132, under the partition 140, and into the chamber 72.

As viewed from Figure 9, as the container web 24 passes through the liquid lock, it follows a descending linear path, represented by the web portion 141, which is mutually tangent to the right side of the roller 1 34 and left side of the roller 138, and an ascending linear path represented by the web portion 142, which is mutually tangent to the right side of the roller 138 and the left side of the roller 136.

Preferably, the ascending and descending paths 141, 142 are inclined in the same direction from the vertical, i.e., the paths are more or less parallel, as opposed to intersecting. This permits the container caps 25 to be tilted slightly upward during traverse of one of the paths 141, 142, while being tilted slightly downward during traverse of the other of the paths 141, 142. Thus, the caps 25 are inverted during traverse of the path 142, relative to the paths 141, so that any air trapped in recesses (e.g., under the lip of the cap, or in the top of the cap) will escape during traverse of one or the other of the paths, thereby ensuring that the sterilant contacts all exposed surfaces of the caps 25.

It is also preferable to orient the immersed roller 138 so that the point of tangency of the web portion 142 and the roller 1 36 is to the left, as viewed in Figure 9, of the point of tangency of the web portion 142 and the roller 138. This orientation results in a relatively inverted orientation of the web portions 141 and 142, which tilts the caps 25 slightly upward through their descending path 141, and slightly downward during their ascending path 142. The roller 1 36 should be sufficiently far above the fluid level so that a portion of the ascending path 142 is above the fluid level, thereby permitting any recesses in the tops of the caps 25 (or other outward facing recesses) to drain. The container web then traverses the roller 136 and is reoriented to a horizontal position for passage through the drying chamber 72.This inverts the web relative to its orientation through the ascending path 141, so that any inwardly facing recesses on the caps 25 can drain. Thus, by orienting the rollers in the foregoing manner, all exposed surfaces, including recesses, of the caps 25 are coated with the sterilant, and allowed to drain. It will be understood that it may also be desirable to include an air-jet (not shown) near the entrance of the drying chamber 72, to ensure that the caps 25 are completely dried by the time they reach the filling mechanism 30.

It will be noted that, in Figure 9, the caps 25 are oriented so that they project away from the rollers 134, 1 36, but project toward the surface of the roller 138. Thus, in order to permit the surface of the containers 24 to bear against the surface of the roller 1 38 without interference by the caps 25, the roller 1 38 is provided with a notch 146 (shown in phantom lines) to receive the cap 25.

In order to remove excess sterilant from the web of containers 24 after they ascend from the reservoir 132, the present invention includes a squeegee 150, mounted on a bracket 152, projecting from the top of the chamber, above the roller 1 36. The squeegee 1 50 bears against the top side web of containers during their traverse of the roller 136, so that the container web passes between the roller 1 34 and squeegee 1 50. Excess sterilant is removed from the top of the containers by the wiping action of the squeegee, while excess sterilant is removed from the bottom side of the web 24 as a result of the pressure between the web 24 and roller 136 at the point of tangency of the path 142 with the roller 136.

Since the excess sterilant is removed at the roller 136, it is preferable to position this roller so that it is above the reservoir 132, to permit such excess sterilant to drain back into the reservoir 1 32.

The present invention, therefore, provides an aseptic environment for filling premanufactured, prepackaged, or precapped, and presterilized flexible containers, connected in continuous web form. By using the overwrap bag to form a relative sterile tunnel for the web of containers, the bioload on the containers is significantly reduced.

Because of this reduced bio-load, it requires less sterilant contact time, and/or temperature levels, to ensure an adequate "kill" and provide the required aseptic environment during the filling process. Thus, the reduced bio-load permits the web of containers 24 to be advanced through the apparatus more rapidly, for a given set of conditions, than would otherwise be possible.

Claims (23)

Claims

1. In a container filling apparatus comprising (a) feed means for serially advancing containers, connected in a continuous web, from an entry port to a dispensing port, and (b) an aseptic filling compartment between said ports having a filling means for filling said containers, a method for introducing said containers into said apparatus and dispensing them from said apparatus without introducing contaminants into said aseptic filling compartment, said method comprising:: applying a positive pressure to said aseptic filling compartment, to maintain an aseptic environment in said compartment, by introducing a sterile gas therein; providing said web of containers prepackaged in a sealed overwrap container and presterilized in said overwrap container; forming an opening in said overwrap container to permit connection of said overwrap container to said entry port; operably connecting one end of said continuous web of containers to said feed means to permit said feed means to advance said continuous web of containers through said apparatus from said entry port to said dispensing port; sealing said opening in said overwrap container to said entry port to provide a relatively sterile tunnel for reducing contamination on said containers;; passing said containers through a liquid lock filled with an antiseptic liquid, as they are advanced from said entry port to said filling chamber by said feed means; heating said containers, prior to reaching said filling chamber; advancing said containers to said aseptic filling chamber, by said feed means, after said containers are heated, to permit said containers to be filled by said filling means; and dispensing said containers, after they are filled, through said dispensing port.

2. A method for introducing and dispensing a continuous web of containers into a filling apparatus, as claimed in claim 1, wherein said containers are inverted while immersed in said antiseptic liquid to release air trapped on said containers.

3. A method for introducing and dispensing a continuous web of containers into a filling apparatus, as claimed in claim 1, wherein said containers are inverted in said aseptic filling compartment after passing through said liquid lock to drain said antiseptic liquid from all surfaces of said containers.

4. A method for introducing and dispensing a continuous web of containers into a filling apparatus, as claimed in claim 1, additionally comprising stripping said antiseptic liquid from said containers after passage thereof through said liquid lock.

5. A method for introducing and dispensing a continuous web of containers into a filling apparatus, as claimed in claim 1, additionally comprising the step of applying a positive pressure within said overwrap container by introducing sterile gas therein.

6. In a container filling apparatus, for fiiling flexible, premanufactured containers, connected in a continuous web, a method of reducing the bio-load on said containers during inputting said containers into said container filling apparatus, comprising: providing said flexible, premanufactured web of containers in a sealed overwrap container; introducing a flow of sterile air into said overwrap container to create a positive pressure therein; forming an opening in said overwrap container to permit said web of containers to be operatively connected to feed through an opening in said apparatus, said flow of sterile air reducing entry of contaminants into said opening in said overwrap container; sealing said opening in said overwrap container to said opening in said apparatus to form a relatively sterile tunnel for protecting said containers against contamination; and guiding said containers through a liquid lock into said container filling apparatus.

7. A container filling apparatus, for aseptically filling premanufactured, presterilized, flexible containers, connected in a continuous web, said apparatus comprising: (1) filling means for filling said flexible containers; (2) a chamber, having: (a) a semi-aseptic sub-chamber for receiving said premanufactured, presterilized, containers, (b) a filling compartment, connected to said filling means, and (c) an outlet mouth for dispensing said premanufactured, presterilized containers after filling by said filling means; (3) means for providing an aseptic environment in said filling compartment; (4) means for serially advancing said flexible containers through said chamber, from said semi-aseptic sub-chamber to said outlet mouth; and (5) a liquid lock separating said semi-aseptic sub-chamber from said filling compartment for sterilizing the exterior of said containers as they are advanced through said chamber.

8. A container filling apparatus, as claimed in claim 7, wherein said liquid lock comprises means for applying a sterilizing agent to the exterior of said flexible containers.

9. A container filling apparatus as claimed in claim 8, wherein said chamber additionally comprises means for drying said sterilizing agent.

10. A container filling apparatus, as claimed in claim 9, wherein said drying means comprises means for providing a flow of heated sterile air across said containers.

11. A container filling apparatus, as claimed in claim 7, wherein said means for providing an aseptic environment in said filling compartment comprises means for maintaining said filling compartment at a positive pressure.

12. A container filling apparatus, as claimed in claim 11, wherein said maintaining means additionally maintains said semi-aseptic subchamber at a positive pressure.

1 3. A method of guiding a continuous web of interconnected, flexible containers from a supply carton to a filling machine and for sterilizing the outside of said web during said guiding, comprising: connecting an overwrap bag associated with said carton to the mouth of a semi-aseptic chamber to provide a semi-aseptic path for said web between said carton and said semi-aseptic chamber; drawing said web through said semi-aseptic chamber and through a liquid lock into an aseptic chamber; and drying said web prior to drawing the containers thereof to said filling machine.

14. A method as claimed in claim 13, additionally comprising inverting said web in the liquid of said liquid lock to release air trapped on said containers and thereby assure coating of all exterior surfaces of said web in said liquid lock.

1 5. A method as claimed in claim 13, additionally comprising inverting said web in said aseptic chamber to drain liquid from said liquid lock from all surfaces of said containers.

16. A method as claimed in claim 13, additionally comprising passing said web between a roller and a squeegee in said aseptic chamber to strip liquid from said liquid lock from surfaces of said container.

1 7. A method as claimed in claim 13, wherein said drawing step comprises passing said web over a roller immersed in said liquid lock.

1 8. A filling apparatus for a continuous web of flexible, interconnected containers, comprising: (1) a ciosed chamber providing a sealed conduit for passage of said webs, said chamber having: (a) a first semi-aseptic region, bounded by an inlet mouth of said chamber; and (b) a second aseptic drying region; (2) said first and second regions including a common bath of sterilizing fluid; (3) means located within said bath for guiding said web beneath the surface of said bath; and (4) a partition separating said first and second regions above said surface of said bath.

1 9. A filling apparatus as claimed in claim 18, additionally comprising a roller positioned above said guiding means, said roller guiding a segment of said web from said guiding means, the point of contact of said segment with said roller being closer to said semi-aseptic region than the point of contact of said segment with said guiding means to invert said web above said common bath.

20. A filling apparatus as claimed in claim 19, additionally comprising a squeegee pressing against said web and said roller for stripping said sterilizing fluid from said web.

21. Apparatus for filling a continuous web of interconnected containers comprising: a semi-aseptic chamber; an aseptic chamber; a liquid lock separating said semi-aseptic chamber from said aseptic chamber, said liquid lock comprising: a bath of sterilizing liquid; and a partition separating said aseptic chamber from said semi-aseptic chamber above said bath, the lower edge of said partition immersed in said bath; and means for guiding said web sequentially, through said semi-aseptic chamber, said liquid lock and said aseptic chamber.

22. A method for introducing and dispensing a continuous web of containers into a filling apparatus, substantially as hereinbefore described with reference to the accompanying drawings.

23. A container filling apparatus, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.