WO2009063199A2

WO2009063199A2 - System, method and apparatus

Info

Publication number: WO2009063199A2
Application number: PCT/GB2008/003820
Authority: WO
Inventors: Rickey Dean; Steven Troy Wineman; Robert Thomas Jacques; Scott Douglas Askegard
Original assignee: Elopak Systems Ag; Burrows, Anthony, Gregory
Priority date: 2007-11-14
Filing date: 2008-11-14
Publication date: 2009-05-22
Also published as: WO2009063199A3

Abstract

A steam sterilization system for a conveyor wash using a submicron filter (24) that can cope with transition from lower pressure flow of water to higher pressure flow of steam. Water flows through the submicron filter when the system is in a first operating mode, and steam flows through the submicron filter when the system is in a second operating mode. The submicron filter is such that predetermined values of steam pressure and temperature can be applied for a sustained period of time without damaging the filter, thereby avoiding reducing the efficiency of the filter.

Description

SYSTEM, METHOD AND APPARATUS

The present invention relates to a system for wetting, such as washing and/or lubricating, an element of a packaging machine, a corresponding method, and an apparatus and a method usable therein; in particular, but not exclusively, a chain wash lubrication system, more specifically, the use of a steam sterilisation arrangement and a method of sterilizing a chain wash lubrication system.

Form-fill-seal packaging machines are known in which flat carton sleeves are fed to mandrels of a rotary spider, bottom-broken and-sealed, then stripped off the mandrels into a chain conveyor which comprises two endless parallel chains defining between them pockets for receiving respective, partially formed cartons. The chain conveyor indexes the cartons in a single-file arrangement through a plurality of operating stations, including to one or more locations underneath one or more product filler nozzles. The product nozzle(s) fill(s) the cartons with a product and the cartons are then advanced to the next station by the chain conveyor.

Over time, heat disseminating from various operating stations and friction can result in permanent stretching of the chains and other deformation of the chain conveyor. This deformation can necessitate replacement of chain conveyor components or the repositioning of the filler nozzle(s) along the path of the chain conveyor so that the nozzle(s) align(s) with the carton orientation. If the product nozzle(s) is/are repositioned, other operating station components must also be moved, which is an undesirable time-consuming expense. To reduce deformation of the chain conveyor, chain wash lubrication systems spaced above the chain conveyor are used to supply a non-sterilising wetting liquid in the form of a cooling lubricant, most likely water, to the chain conveyor. The water functions as a natural chain cooler and lubricant. A common problem with chain wash lubrication systems is microbiological contamination. Microbiological contaminants, such as coliform bacteria, in the washing liquid are filtered out by an in-line sub-micron filter, which is normally a 0.2 micron filter in order to be able to trap the bacteria. This helps remove such contaminants which otherwise may come in to contact with the product, resulting in a poor end product shelf life. In order to sterilise the chain wash lubrication system internally, pressurised steam has been used in the past. The steam needs to be provided at a desired flow rate, temperature and pressure for a set time through the system, including through the 0.2 micron filter. Preferably, steam pressures through the system are required to be maintained at a minimum of 20 p.s.i. (137,900 N./m².) in order to maintain the temperature (through the steam being superheated) and to clear the system of residual washing water and any condensate. In conventional systems, the 0.2 micron filter oftentimes collapses during attempts at steam-sterilising the system if pressure above 10 p.s.i. (68,950 N./m².) is attempted. This has resulted in lack of a proper sterilisation procedure in the field.

Another common problem is that water can become trapped in a needle valve orifice of the chain wash lubrication system. In order to force out the trapped water so that the chain wash lubrication system can be sterilised, pressurised air or steam is applied at a high enough pressure to evacuate the wetting liquid from the orifice. Even at pressures of 20 to 30 p.s.i. (137,900

N./m². to 206,800 N./m².), the orifice has not been subjected to proper lubricant purging.

The machine normally includes a clean-in-place (CIP) system which is used for cleaning internally particularly the product-filling equipment of the machine. Since, during filling and during indexing of the filled, but not yet top- sealed cartons, various parts of the machine may undesirably receive splashes of product, the machine may have a sanitizing system for washing from those parts the splashes of product.

According to one aspect of the present invention, there is provided a system for wetting an element of a packaging machine, comprising at least one outlet serving to dispense a non-sterilising, wetting liquid, ducting extending to said at least one outlet for leading said wetting liquid thereto, a first device serving to supply said wetting liquid to said ducting, a second device serving to supply a sterilising fluid to said ducting for flowing out through said at least one outlet, and a sub-micron filter in said ducting and arranged to filter microorganisms from said wetting liquid and to be sterilised by said sterilising fluid, characterized in that said filter is capable for sustaining, without significant reduction of its efficiency, a pressure differential of about 20 pounds per square inch (137,900 Newtons per square metre) for intermittent periods, each continuous and of 5 minutes, at a temperature of 200° Fahrenheit (93.33° Celsius).

According to another aspect of the present invention, there is provided a packaging method including supplying non-sterilising wetting liquid through ducting containing a sub-micron filter to at least one outlet, while said filter filters micro-organisms from said wetting liquid, supplying sterilising fluid through said ducting and said filter to said at least one outlet and thereby rendering said micro-organisms non-viable, characterized by subjecting said filter to a differential pressure of between about 20 and about 30 pounds per square inch (about 137,900 and about 206,800 Newtons per square metre) for intermittent periods, each continuous and of between about 5 minutes and about 10 minutes, at a temperature of between about 200° Fahrenheit (93.33° Celsius) and about 275° Fahrenheit (135° Celsius), without significant reduction of the efficiency of said filter. Owing to those aspects of the invention, it is possible to avoid any significant reduction of the efficiency of the filter and thus possible to avoid the product being packaged being significantly contaminated by micro-organisms in the wetting liquid.

Advantageously, the filter is capable of sustaining, without significant reduction of its efficiency, a pressure differential of between 20 p.s.i. (137,900 HJm².) and 30 p.s.i. (206,800 N./m².) for intermittent periods, each continuous and of ten minutes, at a temperature of about 275^° F (135^°C).

The system may include at least one temperature sensor in thermal communication with any sterilising fluid flowing in the region(s) of the outlet(s), and an adjusting device for use in adjusting the second device according to the response of the temperature sensor(s). In this way, it is possible to ensure that the sterilising temperature is maintained to the or each outlet itself.

If the machine has a flow-resisting valve in the ducting and the wetting liquid might be difficult to push from the valve even under the pressure of the sterilising fluid, it is possible to provide a conduit extending to a location at the ducting downstream of the valve and serving to introduce such sterilising fluid into the ducting at that location and thereby produce suction on the wetting liquid in the valve, so as also to produce a pulling of that wetting liquid from the valve. In a preferred arrangement, the conduit extends from upstream of the valve to downstream thereof and thus by-passes the valve. With that by-pass arrangement, it is advisable to provide a temperature sensor in thermal communication with any sterilising fluid flowing through the valve, so as to ensure that, in spite of the by-pass, which provides the easiest path for flow of the sterilising fluid, it can be ensured that the valve itself is sterilised.

- A - According to a third aspect of the present invention, there is provided apparatus comprising ducting for flow of liquid, a flow-restricting valve in said ducting, and a conduit extending to a location at said ducting downstream of said valve and serving to introduce fluid into said ducting at said location and thereby produce suction on any said liquid in said valve.

According to a fourth aspect of the present invention, there is provided a method including causing liquid to flow through ducting containing a restriction, ceasing the flow of liquid through the restriction, and introducing fluid into said ducting at a location downstream of said restriction and thereby producing suction on any said liquid in said restriction.

Owing to those two aspects of the invention, the introduction of fluid into the ducting at the location downstream of the valve and the suction produced thereby on any liquid in the valve tends to pull the liquid from the valve.

Advantageously, such fluid is also supplied to upstream of the valve and thus also pushes the liquid from the valve.

According to a fifth aspect of the present invention, there is provided a system for wetting an element of a packaging machine, comprising at least one outlet serving to dispense a non-sterilising, wetting liquid, ducting extending to said at least one outlet for leading said wetting liquid thereto, a first device serving to supply said wetting liquid to said ducting, and a second device serving to supply a sterilising fluid to said ducting for flowing out through said at least one outlet, characterized in that at least one temperature sensor is arranged for thermal communication with any said sterilising fluid flowing in the region(s) of said at least one outlet, and an adjusting device is arranged for use in adjusting said second device according to the response of said at least one temperature sensor. According to a sixth aspect of the present invention, there is provided a packaging method including supplying non-sterilising, wetting liquid through ducting to at least one outlet, dispensing said wetting liquid from said at least one outlet onto an element of a packaging machine, and, while said liquid has ceased flowing through, supplying sterilising fluid through said ducting to said at least one outlet, characterized by sensing at least one temperature in the region(s) of said at least one outlet, and adjusting the supply of said sterilising fluid if and when said at least one temperature differs from at least one desired value.

Owing to those two aspects of the invention, it is possible to ensure that the ducting is sterilised right up to the outlet(s).

The invention is particularly applicable to a steam sterilisation arrangement for sterilising a chain wash lubrication system without damaging a submicron filter. Owing to the invention, the submicron filter can cope with transition from the lower pressure flow of wetting liquid, particularly water, to the higher pressure flow of steam. When the system is in a first operating mode, water flows through the chain wash lubrication system, including through the submicron filter, and exits through dispensing nozzles to cool and lubricate the chain conveyor. When the system is in a second operating mode, sterilising steam flows through the chain wash lubrication system, including through the submicron filter, and exits through the dispensing nozzles. Because of the invention, a predetermined value of steam pressure can be applied for a sustained period of time without damaging the submicron filter, thereby avoiding contaminants such as coliform bacteria from being delivered in the washing and lubricating water.

Advantageously, the chain wash lubrication system includes a bypass arrangement used to draw trapped water out of a restricting valve in the chain wash lubrication system. The trapped water can be located in (and upstream of) manual needle valves and is forced out prior to or contemporaneously with the advancement of the sterilising steam flow through the chain wash lubrication system.

In order that the invention may be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings, wherein:

Figure 1 is diagram of fluid circuitry of one model of form-fill-seal packaging machine, and

Figure 2 is a diagram of fluid circuitry of another model of form-fill-seal packaging machine.

Referring to Figure 1, there is seen a CIP/sanitizer supply arrangement 2 which includes a supply tank 4 and, downstream thereof, a pump 6 and a pneumatically-operated valve 8 for switching flow from the tank 4 to a CIP circuit (not shown) or to a sanitizing circuit having an inlet conduit 10, or terminating any flow. Rather than buying the arrangement 2, the purchaser of the machine may choose to install his own CIP/sanitizer arrangement, in which case an item 12 consisting primarily of a pneumatically operated liquid flow control valve 14 would be provided to allow connection of his own arrangement. Water for use in sanitizing certain parts of the machine and in washing and lubricating the two conveyor chains is supplied, by way of a relatively coarse filter (a 0.6 micron filter) 16, a pneumatically operated on-off valve 18, a water pressure regulator 20 and a non-return valve 22 to a fine filter (0.2 micron filter) 24 having a pneumatically operated on-off drain valve 26 for draining water from the filter 24. The non-return valve is one of a number of non-return valves 22 which determine the permitted direction of flow of the various fluids (such as water, sanitizing additive, air and steam) which are supplied at various times to the circuitry shown. The water, possibly mixed with a sanitizing additive from the tank 4, is supplied to a manifold 28 to dispensing nozzles 30 through pneumatically- operated on-off valves 30 for use in sanitizing machine parts, for example the rotary spider and the carton bottom breaker, where the remaining of the sanitizing liquid on the parts is not of particular consequence; through pneumatically-operated on-off valves 34 and 36 to delivery nozzles 38 for sanitising parts of the machine (for example top breakers, cap-applicator anvils, and carton mandrels) where the remaining of sanitizing liquid on the parts is definitely unwanted; and through a needle valve 40 to delivery nozzles 42 for washing and lubricating of the conveyor chains. Between the valve 36 and the nozzles 38 is a drain valve 44, whilst an optional delivery nozzle for at least the water is illustrated at 46. Air is introduced through a pressure regulator 48 having a pressure gauge 50 and via a pneumatically-operated on-off valve 52 into the nozzles 38 to blow the sanitizing liquid from the relevant machine parts, particularly in order to prevent the liquid from entering open-topped cartons. An optional nozzle 54 delivering air only is also shown. Steam at a pressure of, say, 60 p.s.i. (413,700 NJm.².) is supplied to a pressure regulator 56, where the steam pressure is reduced to at least about 20 p.s.i. (137,900 N./m.².), to serve as the sterilizing fluid. Downstream of the regulator 56 is a pressure gauge 58 and a pneumatically-operated on-off valve 60 whereby the steam passes to upstream of the filter 24 and flows through the same and, with the valves 30 and 34 closed, to the nozzles 42 and so sterilizes internally not only the filter 24 but also the manifold 28, the needle valve 40 and the nozzles 42 and the ducting interconnecting those items, the steam escaping from the nozzles 42 into the atmosphere about the conveyor chains.

It will be appreciated that, instead of pneumatically-operated on-off valves, electrically-, hydraulically-, or manually-operated valves can be used. In a first operating mode, which includes production periods, water is supplied, possibly with a sanitizing additive from the tank 4, to all of the nozzles 32,38,42 and 46, whilst air is supplied to the nozzles 38 and 54.

In a second operating mode, during which there is no production, the valve 18 is closed to prevent the flow of water, the valve 8 is operated to prevent supply from the tank 4 and the valve 60 is opened to allow the flow of the sterilizing steam from the pressure regulator 56, the steam exiting therefrom being substantially at a predetermined temperature. The regulator 26 controls the pressure and the rate of flow of the sterilizing steam towards the nozzles 42, the valves 30 and 34 being closed to prevent steam from reaching the nozzles

32, 38 and 46. The valve 60 allows the steam to flow for a predetermined period of time and the regulator 26 maintains a predetermined pressure and a predetermined rate of flow.

The submicron filter 24 is some flow distance away from the valve 60, but nevertheless the steam regulator 26 causes the steam to flow through the filter 24 at predetermined pressure and sterilizing temperature for the predetermined period of time. The filter 12 withstands an applied steam flow of a pressure greater than or equal to 20 p.s.i. (137,900 N./m.².) and greater than or equal to 200^° F (93.33°C) for a minimum of five minutes. Preferably, the steam flow withstood ranges from 20 p.s.i. (137,900 N./m.².) to 30 p.s.i. (206,800 N./m.².) at 200⁰F (93.33°C) to 275°F (135°F). Preferably, the steam flow is maintained for 10 to 15 minutes. For example, a 0.2 micron filter by Graver Technologies having a polyethersulphone membrane cartridge with Viton gasket seals that can withstand a steam flow of greater than or equal to 20 p.s.i. (137,900 N./m.².) and greater than or equal to 200⁰F (93.33^°C) can be used. It is understood that any suitable filter that withstands these predetermined values can be used. For example, a filter that can withstand only 10 p.s.i. (68,950 NJm.².) cannot be utilized since the filter will become damaged when the necessary predetermined values are used, thereby allowing the water to remain contaminated when passing through the filter.

The needle valve 40 (of which there is at least one) is spaced some distance away from the submicron filter 12. Since the machine is large, e.g. 22 feet (6.706m.) long, the needle valve 40 aids in reducing water pressure to the chain wash nozzles 42, so as to reduce the risk of the water splashing onto, but particular into, the cartons during the first operating mode. The needle valve 40, which is manually adjustable in one embodiment, acts as a restrictor, thereby reducing the water pressure to be delivered to the nozzles 42. When in the second operating mode, the steam flow advances through the needle valve 40 and continues to the nozzles 42 where the steam escapes into the atmosphere.

Referring generally to Figures 1 and 2, to ensure sterilization of the chain wash lubrication system, the steam flow should maintain the dispensing nozzles

42 at greater than or equal to 200° F (93.33°C) for a minimum of 10 minutes.

Preferably, the nozzles 22 are maintained in a range of from 200°F (93.33°C) to

275° F (135°C) for preferably 10 to 15 minutes.

Referring particularly to Figure 2, nozzle end needle valves 62 are disposed upstream of respective nozzles 42A' of each of two groups of four nozzles 42. Since those nozzles 42A' are nearest in flow distance to the water supply through the coarser filter 16, the valves 62 serve to balance the water pressure during the washing and lubricating of the chains. It will be understood that one or more nozzle end needle valves would be used depending upon the circumstances.

To prevent trapped water from not being purged out of the chain wash lubrication system when in the second operating mode, a bypass arrangement generally shown at 64 in Figure 2 can be used. For example, water can become trapped in areas between the restrictive nozzle end needle valves 62 and the respective ducting junctions 66 first upstream thereof when the applied steam pressure reaching those areas is less than a water-forcing value, because the steam takes easier paths from those junctions 66, namely to the other nozzles 42. In order to evacuate the trapped water so that the whole of the interior of the chain wash lubrication system can be sterilized, the bypass arrangement 64 is provided for introducing steam flow downstream of the end needle valves 62, which effectively creates a vacuum which draws trapped water through the valves 62, by what may be termed a "syphoning" effect. The bypass arrangement 64 includes an on-off valve 68 for controlling the bypass arrangement 64, and a branching, bypass conduit 70. One end of each of the branches of the bypass conduit 70 is connected between the respective valves 62 and the respective nozzles 42A'.

When the valve 68 is on, it allows the steam to bypass the respective needle valves 62 and flow through to downstream of those valves 62. This creates a vacuum acting on the valves 62, which causes the trapped water or steam to be pulled through the respective valves 62 and purged out of the nozzles 42A¹. The valve 68 can be opened prior to or contemporaneously with the valve 60.

In the version of Figure 2, the water on-off valve 18 and the water pressure regulator 20 are disposed upstream of the coarser filter 16, whilst a water flow detector 72 and a water pressure gauge 74 are disposed downstream of the filter 16 but before the filter 24.

Again referring to Figure 2, one or more of the nozzles 42, in this case two nozzles 42A and 42A' in each group of four, are at flow distances from the steam on-off valve 60 greater than are the other nozzles 42 and, at the nozzles 42A and 42A', there are provided respective thermocouples 76 which sense the temperatures of those nozzles and, thus, of the sterilizing steam flowing through them and the regulator 56 is, if necessary, adjusted manually or automatically in order to ensure that the sterilizing temperature is attained in all of the nozzles 42. Because of the provision of the by-pass arrangement 64, in order to ensure that the sterilizing temperature is attained also in the needle valves 62, the needle valves are provided with respective thermocouples 78. These thermocouples 68 also show that sterilizing steam is actually reaching the needle valves 62 and thus that any water trapped therein has been purged therefrom.

Claims

1. A system for wetting an element of a packaging machine, comprising at least one outlet serving to dispense a non-sterilising, wetting liquid, ducting extending to said at least one outlet for leading said wetting liquid thereto, a first device serving to supply said wetting liquid to said ducting, a second device serving to supply a sterilising fluid to said ducting for flowing out through said at least one outlet, and a sub-micron filter in said ducting and arranged to filter micro-organisms from said wetting liquid and to be sterilised by said sterilising fluid, characterized in that said filter is capable of sustaining, without significant reduction of its efficiency, a pressure differential of about 20 pounds per square inch (137,900 Newtons per square metre) for intermittent periods, each continuous and of 5 minutes, at a temperature of 200° Fahrenheit (93.33^° Celsius).

2. A system according to claim 1, wherein said filter is capable of sustaining, without significant reduction of its efficiency, a pressure differential of between 20 pounds per square inch (137,900 Newtons per square metre) and 30 pounds per square inch (206,800 Newtons per square metre) for intermittent periods, each continuous and of 10 minutes, at a temperature of about 275° Fahrenheit (135° Celsius).

3. A system according to claim 1 or 2, and further comprising at least one temperature sensor arranged for thermal communication with any said sterilising fluid flowing in the region(s) of said at least one outlet, and an adjusting device for use in adjusting said second device according to the response of said at least one temperature sensor.

4. A system according to any preceding claim and further comprising a flow- restricting valve in said ducting and a conduit extending to a location at said ducting downstream of said valve and serving to introduce said sterilising fluid into said ducting at said location and thereby produce suction on any said wetting liquid in said valve, said outlet, or one of the plurality of outlets being downstream of said valve.

5. A system according to claim 4, wherein said conduit extends from upstream of said valve to downstream thereof and thus by-passes said valve.

6. A system according to claim 4 or 5, and further comprising a temperature sensor arranged for thermal communication with any said sterilising fluid flowing through said valve.

7. A system according to any one of claims 4 to 6, and further comprising another conduit extending from said ducting at a location upstream of said valve and by-passing both said valve and the outlet(s) downstream of the valve.

8. A packaging machine including a system according to any preceding claim.

9. A machine according to claim 8, wherein said element is a container- conveying chain.

10. A packaging method including supplying non-sterilising wetting liquid through ducting containing a sub-micron filter to at least one outlet, while said filter filters micro-organisms from said wetting liquid, dispensing said wetting liquid from said at least one outlet onto an element of a packaging machine, supplying sterilising fluid through said ducting and said filter to said at least one outlet and thereby rendering said micro-organisms nonviable, characterized by subjecting said filter to a differential pressure of between about 20 and about 30 pounds per square inch (about 137,900 and about 206,800 Newtons per square metre) for intermittent periods, each continuous and of between about 5 minutes and about 10 minutes, at a temperature of between about 200^° Fahrenheit (93.33° Celsius) and about 275° Fahrenheit (135° Celsius), without significant reduction of the efficiency of said filter.

11. A method according to claim 10, and further comprising sensing at least one temperature in the region(s) of said at least one outlet, and adjusting the supply of said sterilising fluid if and when said at least one temperature differs from at least one desired value.

12. A method according to claim 10 or 11, and further comprising restricting the flow of said wetting liquid at a location in said ducting, and, following ceasing of said flow, introducing said sterilising fluid into said flow at a location downstream of the restriction thereof and thereby producing suction on any said wetting liquid at said location.

13. A method according to claim 12, wherein the sterilising fluid introduced at said location has been taken from upstream of the restriction.

14. A method according claim 12 or 13, and further comprising sensing the temperature at a location in thermal communication with the region of the restriction and adjusting accordingly the temperature of the sterilising fluid supplied.

15. A method according to any one of claims 12 to 14, and further comprising branching-off, from the flow of said sterilising fluid in said ducting at a location upstream of the restriction, a branch flow which flows in relatively unrestricted manner to by-pass not only the restriction but also the outlet(s) downstream of the restriction.

16. A method according to any one of claims 10 to 15, wherein said sterilising fluid is steam.

17. A method according to any one of claims 10 to 16, wherein said wetting liquid is water.

18. Apparatus comprising ducting for flow of liquid, a flow-restricting valve in said ducting, and a conduit extending to a location at said ducting downstream of said valve and serving to introduce fluid into said ducting at said location and thereby produce suction on any said liquid in said valve.

19. Apparatus according to claim 18, wherein said conduit extends from upstream of said valve to downstream thereof and thus by-passes said valve.

20. Apparatus according to claim 18 or 19, wherein said ducting leads to an outlet into an atmosphere, and another conduit extends from said ducting at a location upstream of said valve and said outlet and by-passes both said valve and said outlet.

21. A packaging machine including apparatus according to any one of claims 18 to 20.

22. A machine according to claim 21, wherein said apparatus is included in a conveying chain wash system of said machine.

23. A packaging method including causing liquid to flow through ducting containing a restriction, ceasing the flow of liquid through the restriction, and introducing fluid into said ducting at a location downstream of said restriction and thereby producing suction on any said liquid in said restriction.

24. A method according to claim 23, wherein the fluid introduced into said ducting has been drawn from said ducting at a location upstream of said restriction, whereby said fluid by-passes said restriction.

25. A method according to claim 23 or 24, and further comprising causing said liquid to flow into an atmosphere through a first outlet downstream of said ducting, and, following said ceasing, causing a branch flow of said fluid to flow relatively unrestrictedly to a second outlet while by-passing said restriction and the first outlet.

26. A method according to any one of claims 23 to 25, wherein said liquid is a wetting liquid and said fluid is a sterilant.

27. A system for wetting an element of a packaging machine, comprising at least one outlet serving to dispense a non-sterilising, wetting liquid, ducting extending to said at least one outlet for leading said wetting liquid thereto, a first device serving to supply said wetting liquid to said ducting, and a second device serving to supply a sterilising fluid to said ducting for flowing out through said at least one outlet, characterized in that at least one temperature sensor is arranged for thermal communication with any said sterilising fluid flowing in the region(s) of said at least one outlet, and an adjusting device is arranged for use in adjusting said second device according to the response of said at least one temperature sensor.

28. A system according to claim 27 and further comprising a flow-restricting valve in said ducting and a conduit extending to a location at said ducting downstream of said valve and serving to introduce said sterilising fluid into said ducting at said location and thereby produce suction on any said wetting liquid in said valve, said outlet being downstream of said valve.

29. A system according to claim 28, and further comprising a temperature sensor in thermal communication with any said sterilising fluid flowing in the region of said valve.

30. A packaging machine including a system according to any one of claims 27 to 29.

31. A machine according to claim 30, wherein said element is a container- conveying chain.

32. A packaging method including supplying non-sterilising wetting liquid through ducting to at least one outlet, dispensing said wetting liquid from said at least one outlet onto an element of a packaging machine, and, while said liquid has ceased flowing through, supplying sterilising fluid through said ducting to said at least one outlet, characterized by sensing at least one temperature in the region(s) of said at least one outlet, and adjusting the supply of said sterilising fluid if and when said at least one temperature differs from at least one desired value.

33. A method according to claim 32, and further comprising restricting the flow of said wetting liquid at a location in said ducting, and, following ceasing of said flow, introducing said sterilising fluid into said flow at a location downstream of the restriction thereof and thereby producing suction on any said wetting liquid at said location.

34. A method according claim 33, and further comprising sensing the temperature at a location in thermal communication with the region of the restriction and adjusting accordingly the temperature of the sterilising fluid supplied.

35. A method according to any one of claims 32 to 34, wherein said sterilising fluid is steam.

36. A method according to any one of claims 32 to 35, wherein said wetting liquid is water.