THIN-WALLED CONTAINER BY RADIATION

The present invention relates to thin-walled container forming and non-chemical sterilisation apparatus, along with a method of in-line forming aseptic hermetically- sealed flexible thin-walled containers. Flexible thin-walled containers are well known, and are used for holding a wide- variety of different foods and beverages. One particular example, is a bag-in-box container for a beverage dispenser. In this case, the flexible thin walled container is pre-formed by a third party supplier before being transported to the user for filling.

The problems with this current method begin at the packer, which must first sterilise the manufacturing line and the upper and lower layers being used to form the thin-walled containers. To maintain cost-effectiveness, wet chemical sterilisers, such as Hydrogen Peroxide, are applied to the unjoined layers, requiring large isolated application and drying stations. As the dried and sterilised layers are then being processed and joined to form the container, any contamination results in the or each container being discarded. Consequently, the formation time is long and there can be high wastage.

Wet chemical sterilisation can be undertaken once the container is formed and prior to sealing. However, again, this can lead to issues in terms of chemical residue being left inside the container, and the interior of the container not being fully sterilised if the container utilises complex or irregular geometries. Furthermore, not all pathogens are eliminated by wet chemical sterilisation.

Sterilisation by radiation has been considered, but this has required complex and expensive equipment. X-ray sterilisation, gamma ray sterilisation, and ultra-violet sterilisation have been explored. However, gamma rays are very penetrating, and as a result require bulky shielding for the safety of the operators of the gamma irradiation apparatus. Gamma ray sterilisation also requires secure and safe storage of a hazardous decaying radioisotope, which again presents significant logistical problems.

X-rays are less penetrating than gamma rays, but the traditional high-powered machines also require significant shielding to protect operators from the harmful effect of radiation. Again, therefore, this has been discounted in the present field due to expense and safety issues.

Germicidal UV lamps are generally considered safe, but do not provide the required degree of sterilisation, being largely ineffective in shaded areas, such as within an interior of a preformed container. Ultraviolet light is also known to damage plastics, which may impact the robustness and longevity of the container.

Following formation, the third party supplier must transport the empty thin-walled containers to a specialist sterilisation plant for sterilisation, following which they are then shipped again to final packer for filling. Again, contamination can occur during storage and transportation, resulting in the containers being unusable, in addition to the storage and transportation increasing the costs of the end product.

The present invention therefore seeks to solve these problems, by providing in-line processing to not only form and seal the flexible thin-walled containers, but also to dry non-chemical sterilise the containers following sealing, preferably at the site of filling. According to a first aspect of the invention, there is provided thin-walled container forming and non-chemical sterilisation apparatus comprising : a pre-sterilisation section and a non-chemical sterilisation section arranged in-line to define a guide path through the apparatus; the pre-sterilisation section including a feeder station for feeding at least one flexible container film onto the guide path of the apparatus, a closure insert station at the said guide path for inserting a closure device into the at least one container film, and a sealing station at the said guide path for longitudinally and laterally sealing the at least one container film to form a plurality of hermetically- sealed flexible thin-walled containers; and the non-chemical sterilisation section including an in-line electron beam emitter directed at the guide path for dry sterilising all internal product-contactable surfaces post-formation of the hermetically-sealed flexible thin-walled containers to inline form a plurality of aseptic hermetically-sealed flexible thin-walled containers.

Preferable and/or optional features of the first aspect of the invention are set forth in claims 2 to 14, inclusive. According to a second aspect of the invention, there is provided a method of in-line forming aseptic hermetically-sealed flexible thin-walled containers, the method comprising the steps of : a] in-line forming hermetically-sealed flexible thin-walled containers on a guide path; and b] in-line dry non-chemical sterilising the hermetically- sealed flexible thin-walled containers on the said guide path using electron beam radiation.

Preferably, the method further comprises a step c], subsequent to step b], of aseptically filling and sealing the dry non-chemical sterilised hermetically-sealed flexible thin- walled containers. According to a third aspect of the invention, there is provided a thin- walled container forming and non-chemical sterilisation apparatus comprising : a pre-sterilisation section and a non-chemical sterilisation section arranged in-line to define a guide path through the apparatus; the pre-sterilisation section including a feeder station for feeding at least one flexible film onto the guide path of the apparatus, a closure insert station at the said guide path for inserting a closure device into the at least one container film, and a sealing station at the said guide path for longitudinally and laterally sealing the at least one container film to form a plurality of hermetically-sealed flexible thin-walled containers; and the non-chemical sterilisation section including an in-line irradiator directed at the guide path for dry sterilising all internal product-contactable surfaces post-formation of the hermetically-sealed flexible thin-walled containers to in-line form a plurality of aseptic hermetically-sealed flexible thin-walled containers.

According to a fourth aspect of the invention, there is provided a method of in-line forming aseptic hermetically-sealed flexible thin-walled containers, the method comprising the steps of : a] in-line forming hermetically-sealed flexible thin-walled containers on a guide path; and b] in-line dry non-chemical sterilising the hermetically- sealed flexible thin-walled containers on the said guide path using electron beam radiation.

According to a fifth aspect of the invention, there is provided a method of in-line forming aseptic hermetically-sealed flexible thin-walled containers, the method comprising the steps of : a] in-line forming hermetically-sealed flexible thin-walled containers on a guide path; and b] in-line dry non-chemical sterilising the hermetically- sealed flexible thin-walled containers on the said guide path using irradiation means.

The present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figures la and lb are a side elevational view of one embodiment of in-line thin- walled container forming and non-chemical sterilisation apparatus, split across two figures for clarity and in accordance with the first aspect of the invention;

Figures 2a and 2b is a top plan view of the in-line thin-walled container forming and non-chemical sterilisation apparatus, shown in Figures la and lb and again split across two figures for clarity;

Figure 3 is a top plan view of one kind of an in-line formed aseptic hermetically- sealed flexible thin-walled container, formed by the apparatus shown in Figures 1 and 2;

Figure 4 is a side elevational view of the thin-walled container, shown in Figure

3; Figure 5 is perspective view of an openable closure device of the thin-walled container; and

Figure 6 is an axial cross-sectional view of the openable closure device.

Referring to the drawings, there is shown thin-walled container forming and non- chemical sterilisation apparatus, globally referenced as 10, which comprises a pre- sterilisation section 12, a non-chemical sterilisation section 14, and a post-sterilisation section 16. The three sections 12, 14, 16 are in-line with each other and consecutive thereby defining a guide path 18 through the apparatus 10, and thus enabling one production line for forming an aseptic hermetically-sealed flexible thin-walled container 122. The pre-sterilisation section 12 includes a feeder station 22, a closure insert station 24, a sealing station 26, and a perforator station 28. The feeder station 22 comprises two spool holders 30, 32 for holding a roll of pliantly flexible plastics container film for feeding onto the guide path 18 of the apparatus 10. The spool holders 30, 32 are spaced apart in the longitudinal direction of the guide path 18. In this case, a first roll 34 of pliantly flexible plastics upper layer container film 36 is provided upstream of a second roll 38 of pliantly flexible plastics lower layer container film 40, and the rotational axes of the first and second rolls 34, 38 are parallel or substantially parallel so as to be horizontally or substantially horizontally coplanar. This is beneficial in enabling operator access for mounting and replenishing the first and second rolls 34, 38.

However, the rotational axes of the two rolls 34, 38 could be offset from the horizontal, and for example the two rolls 34, 38 could be vertically stacked. To prevent or limit contamination, the feeder station 22 may include a closable feeder housing 42 in which the two rolls 34, 38 are mountable.

The upper and lower layer container films 36, 40 are, in this case, fluid tight, and may themselves be formed of one or more overlying flexible sub-layers and/or coatings.

Within the feeder station 22, the guide path 18 comprises an upper path portion 44 onto which is feedable the upper layer container film 36, and a lower path portion 46 onto which is feedable the lower layer container film 40. First guide rollers 48 are utilised as required within the feeder station 22, and upper and lower film tensioners 50 are provided to tension the films 36, 40 being drawn off.

The upper and lower path portions 44, 46 of the guide path 18 extend to the closure insert station 24. The closure insert station 24 preferably utilises a bowlfeeder 52 for feeding an openable closure device 54 to an insert machine 56 on the upper path portion 44. The insert machine 56 is positioned on the upper path portion 44 dependent on a size or volume of a flexible thin- walled container 122 being formed, and thus may be slidable longitudinally and laterally relative to the upper path portion 44 and releasably fixed in place as required.

The openable closure device 54 is a gland type of device as best shown in Figures 5 and 6. The closure device 54 includes an outwardly-flanged base 60, a neck 62 which upstands from the outwardly-flanged base 60, and a head 64 at the end of the neck 62 providing an undercut for releasable engagement with a filler nozzle. An exterior side surface 66 of the head 64 may also include one or more ridges and recesses and/or a screw-thread 68 for engaging a dispensing valve or tap.

A lower fluid-tight membrane 70 forming an openable and closeable seal 72 is provided across a bottom surface of the outwardly-flanged base 60, tacked in place by spot welds or other bonding means, for example, at or adjacent to corners thereof so as to overlie a neck opening 74 to thereby initially provide a liquid flow path between the neck opening 74 and the interior of the thin-walled container 122. To enable fluid-tight closure following filling in due course, the lower fluid-tight membrane 70 is formed of a fluid-tight material which has a lower melting point than that of the lower layer container film 40.

An upper fluid-tight membrane 76 is also provided across an upper surface of the head 64, closing a head opening 78 leading to a through-bore 80 of the neck 62 which communicates with the neck opening 74.

With the upper layer container film 36 having a closure aperture 82 punched therein at the closure insert station 24 by a punching machine 84, a said closure device 54 is fed from the bowlfeeder 52 to the guide path 18 and the insert machine 56, which in turn utilises a closure locator device 86 to press the closure device 54 through the closure aperture 82 and fluid-tightly seal the outwardly-flanged base 60 to an underside 88 of the upper layer container film 36. In this case, the openable closure device 54 is provided at or adjacent to a corner of the thin- walled container 122 engaged with the upper layer container film 36, but other positions can be accommodated by moving the punching machine 84 and insert machine 56 relative to the upper path portion 44 of the guide path 18. Furthermore, the closure device 54 could be provided in the lower layer container film 40, as required. The lower path portion 46 is guided horizontally through the majority of the closure insert station 24, below the punching machine 84 and insert machine 56, on second guide rollers 90 before then being directed vertically or substantially vertically to intersect the upper path portion 44 and thus form a unitary or consolidated said guide path 18 through the remainder of the apparatus 10. Although preferably at the insert station 24, the upper and lower path portions 44, 46 of the guide path 18 may meet at the subsequent sealing station 26, instead of at the closure insert station 24.

With the upper and lower container films 36, 40 meeting at the unitary guide path 18, longitudinal and lateral fluid-tight sealing together of the two container films 36, 40 are preferably provided by one or more platen heat sealers 92 at the sealing station 26. Again, the or each platen sealer 92 is positionable relative to the guide path 18 dependent on a size or volume of a required run of thin-walled containers.

Following the sealing station 26 by which a plurality of in-line flexible hermetically- sealed thin- walled containers 94 is formed, the guide path 18 extends to the perforator station 28. It is preferable that the hermetically-sealed thin- walled containers 94 are not separated at this point, and therefore to facilitate subsequent separation, a line of perforations 96 is provided between adjacent lateral seals 98 of consecutive hermetically-sealed thin-walled containers 94. See Figures 3 and 4. The perforator station 28 indexes the incoming flexible hermetically-sealed thin-walled containers 94 and a perforation machine 100, for example, utilising a multi-pointed blade, imparts a series of perforations 96 laterally across the upper and lower container films 36, 40.

The guide path 18 then passes to the non-chemical sterilisation section 14, wherein the flexible hermetically-sealed thin-walled containers 94 are dry non-chemically sterilised.

The non-chemical sterilisation section 14 includes a sterilisation housing 102 forming a treatment chamber 104 therein through which the guide path 18 runs. At least one and in this case three low voltage electron beam sterilisation devices 106, each including at least one electron beam emitter or cannon 108, are provided in the treatment chamber 104. Each electron beam sterilisation device 106 includes a surface targeting portion 110, the electron beam emitter 108 having an outlet 112 for emission of an electron beam through the surface targeting portion 110, a high voltage power unit 114 for preferably converting mains electricity supply to a high voltage and supplying between 100 watts and 3000 watts of power to the electron beam emitters 108, and a connector 116 for connection to a standard mains electricity supply.

To achieve a required level of sterilisation, a specific dosage must be delivered to the interior surfaces 118 of the in-line flexible hermetically-sealed thin-walled containers 94. The current and voltage requirements are selected to deliver the desired dosage to a desired depth across a particular surface area within a suitable period of time. A dosage of, for example, 10 kGy with a penetration depth of about 0.2 mm to 3 mm at a throughput of 425 mm width by 5 metres of length per minute would be suitable for most applications. Careful selection of operating parameters ensures that the power requirements of the device 106 may be fulfilled to suit requirements from high to low acidity products, along with FDA and global hygiene standards, by a single-cable power supply by connection to a conventional industrial mains electricity supply.

The sterilisation housing 102 utilises sufficient shielding to protect operators, but due to the lower energies utilised typically now being in a range of 50 kV to 200 kV and more particularly being in a range of 80 kV to 150 kV, the shielding requirements are less onerous than traditional higher energy electron beam cannons traditionally operating at between 500 kV and 10 MV.

The guide path 18 in the sterilisation housing 102 is directed vertically by third guide rollers 120. This enables the electron beam emitters 108 in the treatment chamber 104 to be positioned horizontally and facing the guide path 18. In this case, two of the electron beam emitters 108a, 108b are provided at one side of the guide path 18, so as to face the lower container film 40, and the third electron beam emitter 108c is provided downstream at the other side of the guide path 18 so as to face the upper container film 36. The perforated line of flexible hermetically-sealed thin-walled containers 94 thus passes on the guide path 18 into the in-line sterilisation housing 102 of the non-chemical sterilisation section 14. Once within the treatment chamber 104 and passing vertically between the low-energy electron beam emitters 108, all internal product-contactable surfaces 118 post-formation of the flexible hermetically-sealed thin-walled containers 94 are irradiated and thus sterilised to Log 6 reduction or better. Due to the hermetically-sealed thin-walled containers 94 being sealed, following irradiation, the closed hermetically-sealed thin-walled containers 94 are aseptic and remain sterile.

The plurality of flexible aseptic hermetically-sealed thin-walled containers 122 then exit the sterilisation housing 102 of the non-chemical sterilisation section 14 on the guide path 18 and pass to the post-sterilisation section 16 for in-line filling. The post- sterilisation section 16 includes a container filler station 124 comprising an aseptic filling machine 126. Since filling may take longer than the formation of the aseptic hermetically-sealed thin-walled containers 122, the container filler station 124 may be fed by a collector container 128, such as a wheeled cart or trolley, as shown in Figure 1. However, this may be dispensed with in favour of other kinds of container. If the aseptic filling machine 126 has a suitable flow rate, then the collector container 128 may be dispensed with altogether.

The aseptic filling machine 126 preferably utilises a sterilised filler nozzle 130 which automatically engages the head 64 of the openable closure device 54 and then punctures the upper membrane seal 76 of each consecutive aseptic hermetically-sealed thin-walled container 122 on the guide path 18. The nozzle 130 is supplied with a liquid food or beverage from a source 132 in communication with the post-sterilisation section 16, enabling filling of the aseptic hermetically-sealed thin-walled container 122 through the lower membrane seal 72, whilst retaining complete sterilisation. On completion of filling and with the thin-walled container 122 typically held at an angle, the lower membrane seal 72 is fully closed, preferably by external heat sealing means 138 liquid- tightly heat sealing a continuous perimeter portion of the lower membrane seal 72 to the outwardly-flanged base 60, thereby preventing leakage and contamination. The filler nozzle 130 is withdrawn and a sterilised cap 134 may be engaged by the aseptic filling machine 126 with the head 64 of the closure device 54.

The in-line formed, sterilised and filled flexible aseptic hermetically-sealed thin-walled containers 136 are then collected when leaving the aseptic filling machine 126 and separated as necessary. Although, in the above-described embodiment, a low voltage electron-beam emitter is utilised, sterilisation using other low-energy irradiation means may be feasible, whereby users and operators are not put at a health risk due to lower shielding but which still enables sterilisation by irradiation in a compact in-line container forming apparatus. It is further possible that the post-sterilisation section may include a separating machine for separating the perforated in-line formed, sterilised and filled aseptic hermetically- sealed flexible thin-walled containers, and may include automatic application of end- user fitments, such as taps or valves, and automatic loading of each container into a box for example utilising chute-loading. It is also feasible that the in-line post-sterilisation section may be dispensed with, should the user only require the formation of in-line formed and sterilised aseptic hermetically- sealed flexible thin-walled containers.

Upper and lower container films are preferably utilised to form the thin-walled containers. However, a single web or blank of container film may be used and folded on the guide path before being sealed at or adjacent to one longitudinal edge and laterally to form the sealed thin-walled containers.

The closure device may not necessarily be openable. The closure device may only be sealable, and in this case the sealed flexible thin-walled container may be slit in order to access the contents. It is therefore possible to provide thin-walled container forming and non-chemical sterilisation apparatus which in-line forms and dry non-chemical sterilises aseptic hermetically-sealed flexible thin-walled containers using low-voltage electron beam radiation or other suitable low energy irradiation means. In particular, but not necessarily exclusively, the walls of the containers are pliantly flexible. It is also possible to provide a single apparatus which in-line forms, dry non-chemical sterilises and fills aseptic hermetically-sealed flexible thin-walled containers, thereby providing an end-to-end in-line product forming apparatus for a single end user without requiring third-party transport and storage costs between formation of the thin-walled containers and filling. The words "comprises/comprising" and the words "having/including" when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined by the appended claims.