GB2585323A

GB2585323A - Packaging apparatus and manifold

Info

Publication number: GB2585323A
Application number: GB1815527.5A
Authority: GB
Inventors: Hurstfield Mark; Barrett Derek
Original assignee: Proseal UK Ltd
Current assignee: Proseal UK Ltd
Priority date: 2018-09-24
Filing date: 2018-09-24
Publication date: 2021-01-13
Anticipated expiration: 2038-09-24
Also published as: GB201815527D0; GB2585323B

Abstract

A manifold 28 for distributing flushing gas to receptacles in a packaging apparatus has a gas inlet and gas outlets 30 fluidly connected by a gas flow passage 50. The outlets are located above the inlet in use and fluidly connected with the receptacles. The gas flow passage 50 is configured such that liquid entering the through the outlets 30 will drain through the flow passage and exit the manifold through the inlet. In an embodiment, a lower surface 56 of the flow passage slopes continuously downwardly from the outlet to the inlet. The manifold may have a body 40 comprising a distribution plate 42 and a cover 44 releasably mounted face to face with the plate, with part of the gas flow passage 50 being defined by recesses in opposed faces of the cover and plate The manifold is suitable for use with a tray sealer to allow cleaning fluid to drain from the manifold.

Description

PACKAGING APPARATUS AND MANIFOLD

Technical Field of the Invention

The present invention relates to packaging apparatus and particularly to heat sealing packaging apparatus such as a tray sealer. The present invention also relates to a gas manifold for use in a packaging apparatus.

Background to the Invention

Tray sealers are widely used to package foodstuffs. Conventional tray sealers have a lower tool for supporting a number of trays containing product, such as foodstuff, which in use is raised to bring the trays into contact with a sealing film positioned above the trays and to urge the film and rims of the trays into contact with a heated upper tool.

This seals the film to the rims of the trays and the film is cut around each individual tray.

To prolong the shelf life of foodstuff packaged in this way it is known to flush the trays with a chosen, typically inert, gas (which may be a mixture of gases) before they are sealed with film. This displaces air from the trays, replacing it with the inert gas in order to slow oxidation or other deterioration ofthe packaged foodstuff This process is known as Modified Atmosphere Packing. The flushing gas is introduced into the trays whilst they are near or in contact with the sealing film, but before the film is sealed to the tray. The flushing gas is supplied from a gas cylinder or other external gas supply via a valve of the tray sealer which is controlled so that gas is only discharged when required. The flushing gas is directed from the supply into inlet ports in the lower tool which in turn direct the gas into the trays. The inlet ports are provided along one side of each tray with corresponding outlet ports on the opposite side through which air displaced from each tray by the flushing gas exits.

The lower tool typically has a number of receptacles aligned in a row which each receive a tray and has flushing gas inlet and outlet ports associated with each receptacle. A gas manifold is attached to the lower tool extending along one side of the row of receptacles. Known gas manifolds include a gas distribution chamber into which the flushing gas is introduced from the supply and which is fluidly connected with inlet gas ports associated with each of the receptacles so that flushing gas is distributed evenly into each of the trays.

Tray sealers and associated equipment must be regularly cleaned to meet stringent hygiene regulations, especially when used for packaging foodstuff. For example, cleaning may be required at the end of each day which typically involves washing the equipment down with a cleaning liquid such as water.

A problem with known gas manifold arrangements for tray sealers is that contaminated cleaning liquid and other matter can enter the manifold through the gas ports during cleaning and build up in the manifold. If the cleaning liquid stagnates in the manifold, this can lead to a build-up bacteria. When the machine is next operated, contaminated cleaning liquid and other matter washed into the manifold may be blown into the lower tool and packaging, potentially contaminating foodstuff packaged by the machine. This problem is exacerbated by the fact that known manifold arrangements are not easily accessible for cleaning without having to strip down large parts of the lower tool.

It is an object of aspects of the present invention to address these problems.

Summary of the Invention

According to a first aspect of the present invention there is provided packaging apparatus comprising a lower tool defining a number of receptacles for receiving product supports and a gas manifold for distributing flushing gas to each of the receptacles, the manifold comprising a manifold body defining a gas inlet for receiving gas from a supply and at least one gas outlet fluidly connected with the receptacles, the at least one gas outlet being located above the gas inlet and the manifold body defining at least one gas flow passage fluidly connecting the at least one gas outlet, wherein the at least one gas flow passage is configured such that liquid entering the manifold through the at least one gas outlet will drain through the at least one gas flow passage and exit the manifold through the gas inlet.

Packaging apparatus in accordance with this aspect of the invention is advantageous as any liquid entering the manifold through the gas outlet, say when the apparatus is cleaned, will tend to drain under the influence of gravity out through the gas inlet and so will not be retained in the manifold.

In an embodiment, the lower tool defines at least one gas inlet port associated with each receptacle for directing a flushing gas into product supports located in the receptacles in use, the at least one gas outlet being fluidly connected with the gas inlet ports. The manifold may define a plurality of gas outlets, each gas outlet being fluidly connected with the at least one gas inlet port of a respective receptacle.

In an embodiment, the gas outlet is defined in an upper surface of the manifold body and the gas inlet is defined in a lower surface of the manifold body.

In an embodiment, at least lower surfaces of the at least one uas flow passage slope downwardly substantially continuously from the at least one gas outlet to the gas inlet.

In an embodiment, the at least one gas flow passage includes an elongate gas distribution chamber and a gas supply passage, said at least one gas outlet being arranged at an upper edge of the gas distribution chamber, the gas distribution chamber being fluidly connected with the gas inlet by the gas supply passage which enters the gas distribution chamber at a position below the at least one gas outlet. In this embodiment, upwardly directed surfaces of the gas distribution chamber may be inclined downwardly towards the gas supply passage, the gas supply passage being inclined downwardly towards the gas inlet. The gas supply passage may enter the gas distribution chamber at a position located substantially centrally of the length of the gas distribution chamber.

The manifold may define a plurality of the gas outlets, each gas outlet being fluidly connected with the gas distribution chamber. Each of the plurality of gas outlets may be fluidly connected with at least one gas inlet port associated with at least one receptacle.

The manifold body may be divided generally vertically into two parts releasably connected together, the parts having opposed surfaces. The two parts of the body may comprise a gas distribution plate and a cover releasably mounted to the gas distribution plate. The gas distribution chamber may be at least partly defined by one or more recesses in the gas distribution plate. The gas supply passage may be at least partly defined by means of one or more recesses in the cover. A seal arrangement may be provided between the gas distribution plate and the cover to prevent gas escaping from the gas distribution chamber and the gas supply passage between the gas distribution plate and the cover.

The distribution plate may be mounted to the lower tool and the cover removably mounted to the distribution plate, the arrangement being configured such that the cover can be removed from the distribution plate whilst the distribution plate remains mounted to the lower tool. The cover may be releasably attached to the distribution plate by means of manually releasable fasteners. The fasteners may be screw threaded fasteners with a handle or other formation enabling them to be inserted and removed by hand, without the need to use a tool. The fasteners may each engage in a respective thread on the distribution plate, which may be provided by means of a captive nut.

In an embodiment, the lower tool has a platform defining the plurality of receptacles arranged in a row and the gas manifold is mounted to the lower tool extending along one side of the receptacles.

In an embodiment, no surfaces are defined within the at least one gas flow passage on which liquid entering the manifold can collect in use.

In an embodiment, no upwardly directed surfaces are defined within the at least one gas flow passage which are horizontal or upwardly directed in a direction from the gas outlet to the gas inlet.

The packaging apparatus may be a tray sealer.

In accordance with a second aspect of the invention, there is provided a gas manifold for use in packaging apparatus, the manifold comprising a manifold body defining a gas inlet for receiving gas from a supply and at least one gas outlet, the at least one gas outlet being located above the gas inlet when the manifold is in an upright, in use, orientation, the manifold body defining at least one gas flow passage fluidly connecting the gas inlet with said at least one gas outlet, wherein the at least one gas flow passage is configured such that in use with the manifold in an upright position, liquid entering the manifold through the at least one gas outlet will tend to drain through the at least one gas flow passage and exit the manifold through the gas inlet.

The gas manifold in accordance with the second aspect of the invention may include any of the features of the gas manifold of the packaging apparatus in accordance with the first aspect of the invention as set forth above.

The gas manifold according to the second aspect of the invention may be suitable for use in the packaging apparatus according to the first aspect of the invention.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a schematic side view of a packaging apparatus in accordance with an aspect of the invention; Figure 2 is a perspective view from one side of the packaging apparatus of Figure Figure 3 is an alternative perspective view from the other side of the packaging apparatus of Figure 1 on a smaller scale; Figure 4 is an exploded, perspective view of part of a lower tool of the apparatus of Figures 1 to 3; Figure 5 7 Figure 6 is a perspective view of the lower tool of Figure 4 in an assembled condition; is an exploded, perspective view of a gas manifold assembly including a gas manifold in accordance with an aspect of the invention and which forms part of the apparatus of Figures 1 to 3; Figure 7 is a cross sectional view through the gas manifold of Figure 6 in an assembled condition; Figure 8 is a perspective view of a cover forming part of the gas manifold of Figures 6 and 7; Figure 9 is a plan view from above of a gas connecting block forming part of the gas manifold assembly of Figure 6; Figure 10 is a plan view from below of the gas connecting block of Figure 9; Figure 11 is a plan view from the front of the gas manifold assembly of Figure 6 shown in an assembled condition and with the cover transparent to enable internal details to be seen; and Figure 12 is a cross sectional view through a gas injector barrel arrangement which can be adopted in the apparatus of Figures I to 3.

References to upper and lower and like terms refer to the apparatus and component parts when oriented as shown in the drawings (which is the orientation in which it is normally intended to be used) but should not be otherwise taken as limiting.

Referring initially to Figures 1 to 5 of the drawings, there is shown packaging apparatus in the form of a tray sealing machine 10. The machine 10 is of a largely conventional type except as explained below and is therefore not described in detail. Briefly, the machine 10 is for sealing trays and comprises a sealing station 12 having a lower tool 14 and an upper tool 16. The tray sealing station 12 seals a number of trays (not shown) simultaneously in batches. In this particular embodiment, the tray sealing station 12 is arranged to seal four trays simultaneously but it should be appreciated that apparatus in accordance with the invention could be adapted to seal more or fewer than four trays in each cycle.

In use, unsealed trays are fed towards the tray sealing station 12 in the direction of arrow A and sealed trays moved away from the sealing station 12 in the direction of arrow B by suitable conveyancing apparatus which may include an infeed conveyor (not shown) an outfeed conveyor (not shown) and transfer arms 18 for carrying the trays between the tray sealing station and the conveyors.

The lower tool 14 includes a base plate 20 and a platform 22 positioned above and mounted to the base plate 20. The base plate 20 is mounted to an actuator (not shown) operable to raise and lower the base plate 20 and hence the platform 22 relative to the upper tool 16. The platform 22 defines a number of recesses or receptacles 24 for receiving trays. In this case the platform defines four receptacles 24 arranged in a row but the number and arrangement of receptacles 24 can be varied and there could be more or fewer than four. A number of gas ports are defined along opposite sides of each receptacle 24. The ports on one side are flushing gas inlet ports through which flushing gas is introduced into a tray in the receptacle whilst the ports 26 on the opposite side are outlet ports through which the pre-existing atmosphere inside the tray exits the tray during flushing. The exit ports 26 can be seen in Figures 4 and 5 and corresponding inlet ports are present on the opposite side of each receptacle. A flushing gas distribution manifold 28 is mounted to the platform extending along the side of the receptacles adjacent the inlet ports. The manifold has four outlets 30 fluidly connected with the inlet ports, an inlet 32 connected with a gas supply, and an internal gas flow passage fluidly connecting the inlet 32 and outlets 30 and arranged to distribute the flushing gas from the inlet 32 to each of the outlets 30. Each of the outlets 30 is located adjacent a respective one of the receptacles 24 and is fluidly connected with the inlet ports associated with that receptacle so that a substantially equal amount of flushing gas is introduced into each tray. Whilst each outlet 30 is positioned adjacent a respective one of the receptacles 24, the outlets 30 open into a shallow channel 34 in the upper surface of the manifold so that all the outlets 30 in the manifold and inlet ports in the platform 22 are fluidly connected to ensure that the flushing gas is distributed evenly.

1' he upper tool 16 includes a number of heating surfaces 36 which correspond in shape and location to the sealing rims of trays located in the receptacles. In use, unsealed trays loaded with product are placed in each of the receptacles when the base plate 20 and the platform 22 are in a lowered, rest position where the platform 22 is spaced from the upper tool. A sheet of sealing film (not shown) is drawn between the upper and lower tools above the trays and in close proximity to the upper tool. The base plate 20 and platform 22 of the lower tool are then raised to a gas flushing position where the rims of the trays are just in contact or nearly in contact with the sealing film, which substantially closes the trays. A flushing gas is then introduced under pressure via the manifold and gas inlet ports in the platform to enter the trays. This displaces air in the trays forcing it out through the outlet ports 26.

After a predetermined time the gas flow is stopped and the actuator raises the base plate 20 and platform 22 further to a sealing position in which the rims of the trays press the film into contact with the heating surfaces 36 in the upper tool, sealing the film to the rim and trapping the flushing gas inside. The upper tool 14 may also have film trimming blades operative to cut the sealing film closely about the outer periphery of the tray rims when sealed.

The actuator then lowers the base plate 20 and platform 22 to the rest position where the sealed trays are transferred to the outfeed conveyor and a new batch of unsealed trays introduced into the platform to begin the next cycle.

A programmable electronic controller (not shown) automatically controls operation of the tray sealing machine 10.

These features of a tray sealing machine will be well understood by a person of ordinary skill in the art.

In accordance with an aspect of the invention, the internal gas flow passage ofthe manifold 28 is configured so that liquid entering the manifold through the outlets 30 drains under the influence of gravity to the gas inlet 32 where it exits the manifold. This is advantageous in preventing cleaning liquid and other matter entering the manifold when the machine 10 is cleaned from being retained in the manifold where it can stagnate and be expelled into trays when packaging is recommenced. Liquid draining from the manifold through the gas inlet 32 may enter a part of the gas supply system which is configured to allow the liquid to be drained out of the system entirely.

The manifold 28 has a manifold body 40 formed in two parts, a distribution plate 42 which is mounted to the lower tool and a manifold cover 44 which is removably mounted to the distribution plate 42. The distribution plate 42 and manifold cover 44 have opposing mating surfaces 46, 48 which extend vertically when the manifold is mounted to the lower tool 14 in its upright, in use position. The internal flow passage 50 includes a distribution chamber 52 defined by means of a recess in the mating face 46 of the distribution plate 42 and a gas supply passage 54 defined by means of a recess in the mating face 48 of the manifold cover 44.

The gas distribution chamber 52 is elongate and opens into the shallow channel 34 formed in the upper edge of the distribution plate 42 through the four outlets 30, which are in the form of elongate slots. The outlets 30 are configured so that each is located adjacent a respective one of the receptacles 24 in the lower tool. It will be appreciated that the number and location of the outlets 30 can be varied depending on the number and location of receptacles. However, it is not essential that the manifold has an outlet 30 for each receptacle 24 as a single common outlet can be used to direct gas into more than one receptacle depending on the arrangement of inlet ports in the platform 22.

The lower surface 56 of the recess that defines the gas distribution chamber 52 angles downwardly from either end towards a semi-circular concave indentation located substantially centrally of the chamber. The gas supply passage 54 has an inner end 60 which fluidly connects with the gas distribution chamber 52 at the centre of the chamber within the semi-circular indentation 58 and extends longitudinally of the manifold towards one end where it opens at the lower edge 62 of the cover to define the gas inlet 32. The gas supply passage 54 slopes downwardly from its inner end 60 to the inlet 32.

The downwardly angled lower surface 56 of the distribution chamber 52 and gas supply passage 54 are configured so that liquid entering the manifold through the outlets 30, say during cleaning of the machine 10, will drain to the centre of the gas distribution chamber 52, enter the gas supply passage 54 and flow down along the gas supply passage and out through the inlet 32. The concave indention 58 need not be semi-circular but could take a different form. Indeed, there need not be a concave indentation at all, provided the gas supply passage is able to connect fluidly with the gas distribution at its lowest point.

The manifold 28 is mounted to the lower tool with the upper edge of the gas distribution plate 42 in engagement with a lower surface of a peripheral flange 64 of the platform, where the inlet ports are located. The distribution plate 42 has three pedestals 66 spaced along its lower edge which engage with the base plate 20 so that the distribution plate 42 acts as part of the structure of the lower tool to support the platform 22 on the base plate 20 on one side. A gas connecting block 68 is located between the lower edge of the manifold 28 and the base plate 20 and forms a manifold assembly together with the manifold. A connecting gas flow passage 70 extends through the block from its upper surface, where the connecting passage 70 is in fluid connection with the manifold gas inlet 32, and its lower surface, where the connecting passage is in fluid connection with a gas supply system.

The gas supply system may include a gas supply conduit mounted in an aperture 72 in the base plate. For example, the gas supply system could include a downwardly directed tubular gas injector barrel 74 as illustrated in Figure 12. The tubular gas injector barrel 74 has an inner axial bore 76 which defines an internal gas supply conduit. The axial bore 76 is closed axially at the lower end of the barrel but opens axially at the upper end 78 of the barrel to define a gas outlet 80. The upper end 78 of the barrel is mounted to the base plate 20 of the lower tool, say in in the aperture 72, so that the outlet 80 of the bore 76 is fluidly connected with the connecting passage 70 in the gas connecting block 68 and hence the manifold gas inlet 32. Towards a lower end of the barrel 74, a radial opening 82 is formed in the side wall of the barrel 74 which opens into the bore 76 to form a gas inlet.

The gas injector barrel 74 passes through a tubular sleeve 84 which forms part of a gas supply. The sleeve 84 defines a cylindrical bore 86 through which the barrel 74 extends. The bore 86 is of a greater diameter than the barrel 74. A lip seal 88 and guide bush 90 is fitted into a counter bore at each opposite end of the sleeve, the bushes 90 holding the seals 88 in place. The bushes 90 and seals 88 centre the barrel 74 within the sleeve 84 so that there is a clearance all around the barrel 15 within the sleeve 84. This allows the barrel 74 to slide axially through the sleeve 84 and forms a substantially gas tight seal between the barrel 74 and the sleeve 84. A radial bore 92 is formed in the sleeve 84 and connects to a gas supply fitting 94 enabling connection, in use, to a supply of flushing gas. The barrel 74 and sleeve 84 are arranged so that the radial opening 82 faces the radial bore 92 in the sleeve 84 when the two are aligned vertically.

The barrel 74 is constrained to move with the base plate 20 as it is moved between its lowered rest position and its raised gas flushing and heat sealing positions, sliding axially through the sleeve 84. Figure 12 shows the barrel 74 when the base plate 20 is in its lowered, rest position. In this position, the radial opening 82 in the side wall of the barrel 74 is located below the tubular gas supply sleeve 84 and is open to atmosphere, whilst the gas supply within the sleeve 84 is closed by the barrel engaging with the seals 88. In this configuration, liquid entering the barrel from the gas supply manifold 28 will flow down through the axial bore 76 and out through the radial opening 82. The lower surface of the bore 76 being curved at 96 to ensure the liquid flows out of the opening 82 and is not retained in the bore 76. This is the configuration which the apparatus will be placed in during cleaning. In use when the base plate 20 is raised to the gas flushing position, the radial opening 82 will be located within the gas supply sleeve 84 opposite the radial bore 92 and gas supply 94 so that flushing gas can flow through the barrel into the gas supply manifold 28.

The gas flow passage 50 in the manifold 28, the connecting passage 70 in the connecting block 68, and the axial bore 76 and radial opening 82 in the barrel form a continuous, downwardly directed flow path through which liquid entering the manifold through the gas outlets 30 is able to drain when the lower tool is in its lower, rest position. However, other arrangements for connecting the gas supply to the manifold which allow liquid to drain from the manifold when the lower tool 14 is in its lower rest position can be adopted.

The manifold cover 44 is releasably secured to the distribution plate 42 by means of three threaded fasteners 98 which are inserted through apertures in an outer face of the cover and engage with corresponding nuts 100 held captive in recesses in a rear face of the distribution plate. As illustrated, the threaded fasteners 98 each have a handle or other formation by means of which they can be inserted and removed manually without the need to use tools. This arrangement enables the manifold cover 44 to be easily removed from the distribution plate 42 whilst the distribution plate remains attached to the lower tool and without having to disassemble the lower tool and without the need to use tools. This is advantageous in allowing for ease of cleaning the internal passages of the manifold.

A first seal 102 is provided between the manifold cover and the distribution plate encircling the gas distribution chamber and the gas supply passage to prevent flushing gas from leaking between the cover and distribution plate. A second seal 104 extends about the periphery of the shallow channel 34 between the upper edge of the distribution plate and the flange 64 of the platform. Third and fourth seals 106, 108 are provided between the gas connecting block 68 and the manifold 28 and the base plate 20 respectively. The seals 102, 104, 106, 108 are located in corresponding grooves defined in the mating face 46 of the distribution plate 42, the upper surface of the distribution plate 42, and the upper and lower surfaces of the gas connecting block 68, respectively.

The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims. For example, the tray sealer may include arrangements for vacuum packing the film about the tray and product. It will also be appreciated that the gas manifold arrangement as described can be adapted for use with packaging apparatus other than tray sealers where there is a need to deliver a flushing gas to multiple packages simultaneously and where it is desirable to prevent liquids, such as cleaning fluid, building up in the manifold and to allow for ease of cleaning of the manifold internally.

Claims

CLAIMS1. Packaging apparatus comprising a lower tool defining a number ofreceptacles for receiving product supports and a gas manifold for distributing flushing gas to each of the receptacles, the manifold comprising a manifold body defining a gas inlet for receiving gas from a supply and at least one gas outlet fluidly connected with the receptacles, the at least one gas outlet being located above the gas inlet and the manifold body defining at least one gas flow passage fluidly connecting the gas inlet with said at least one gas outlet, wherein the at least one gas flow passage is configured such that liquid entering the manifold through the at least one gas outlet will drain through the at least one gas flow passage and exit the manifold through the gas inlet.
2. Packaging apparatus as darned in claim 1, where the at least one gas outlet is defined in an upper surface of the manifold body and the gas inlet is defined in a lower surface of the manifold body.
3. Packaging apparatus as claimed in claim I or claim 2, wherein at least a lower surface of the at least one gas flow passage slopes downwardly substantially continuously from the at least one gas outlet to the gas inlet.
4. Packaging apparatus as claimed in any one of claims 1 to 3, wherein the at least one gas flow passage includes an elongate gas distribution chamber and a gas supply passage, said at least one gas outlet being arranged at an upper edge of the gas distribution chamber, the gas distribution chamber being fluidly connected with the gas inlet by the gas supply passage which enters the gas distribution chamber at a position below the at least one gas outlet.
Packaging apparatus as claimed in claim 4, wherein lower surfaces of the gas distribution chamber are inclined downwardly towards the gas supply passage, the gas supply passage being inclined downwardly towards the gas inlet.
6. Packaging apparatus as claimed in claim 4 or claim 5, wherein the gas supply passage enters the gas distribution chamber at a position located substantially centrally of the length of the gas distribution chamber.
7. Packaging apparatus as claimed in any one of claims 4 to 6, wherein the manifold defines a plurality of the gas outlets, each gas outlet being fluidly connected with the gas distribution chamber and with at least one of gas inlet port associated with at least one receptacle.
Packaging apparatus as claimed in any one of the preceding claims, wherein the manifold body is divided generally vertically into two parts releasably connected together, the parts having opposed surfaces.
9. Packaging apparatus as claimed in claim 8, wherein the two parts of the body comprise a gas distribution plate and a cover releasably mounted to the gas distribution plate.
10. Packaging apparatus as claimed in claim 9, wherein the gas distribution chamber is at least partly defined by one or more recesses in the gas distribution plate and the gas supply passage is at least partly defined by means of one or more recesses in the cover.
11. Packaging apparatus as claimed in claim 10, wherein a seal arrangement is provided between the gas distribution plate and the cover to prevent gas escaping from the gas distribution chamber and the gas supply passage between the gas distribution plate and the cover.
12. Packaging apparatus as claimed in any one of claims 9 to 11, wherein the distribution plate is mounted to the lower tool and the cover is removably mounted to the distribution plate, the arrangement being configured such that the cover can be removed from the distribution plate whilst the distribution plate remains mounted to the lower tool.
13. Packaging apparatus as claimed in any one of the preceding claims, wherein the lower tool has a platform defining the plurality of receptacles arranged in a row and the gas manifold is mounted to the lower tool extending along one side of the receptacles.
14. Packaging apparatus as claimed in any one of the preceding claims, wherein no surfaces are defined within the at least one gas flow passage on which liquid entering the manifold can collect in use.
15. Packaging apparatus as claimed in any one of the preceding claims, wherein no upwardly directed surfaces are defined within the at least one gas flow passage which are horizontal or upwardly directed in a direction of flow from the gas outlet to the gas inlet.
16. Packaging apparatus as claimed in any one of the preceding claims, wherein the lower tool defines at least one gas inlet port associated with each receptacle for directing a flushing gas into product supports located in the receptacles in use, the at least one gas outlet being fluidly connected with the gas inlet ports.
17. Packaging apparatus as darned in claim 16, wherein the manifold defines a plurality of gas outlets, each gas outlet being fluidly connected with the at least one gas inlet port of a respective receptacle.
18. Packaging apparatus as claimed in any of the preceding claims, wherein the apparatus is a tray sealer
19. A gas manifold for use in a packaging apparatus, the manifold comprising a manifold body defining a gas inlet for receiving gas from a supply and at least one gas outlet, the at least one gas outlet being located above the gas inlet when the manifold is in an upright, in use, orientation, the manifold body defining at least one gas flow passage fluidly connecting the gas inlet with said at least one gas outlet, wherein the at least one gas flow passage is configured such that in use with the manifold in an upright position, liquid entering the manifold through the at least one gas outlet will drain through the at least one gas flow passage and exit the manifold through the gas inlet.
20. A gas manifold as claimed in claim 19, the manifold comprising any of the features of the gas manifold in the packaging apparatus of any one of claims 1 to 18.