WO2005075294A1

WO2005075294A1 - Apparatus and method of reducing gas in a filled and sealed bag

Info

Publication number: WO2005075294A1
Application number: PCT/NZ2005/000010
Authority: WO
Inventors: Shane Robert Reckin; Henricus Jacobus Johannes Hermans
Original assignee: Carter Holt Harvey Limited; Technopak Limited
Priority date: 2004-02-05
Filing date: 2005-02-03
Publication date: 2005-08-18
Also published as: UY28740A1; AU2005210587A1; AR050138A1

Abstract

Apparatus and method of reducing gas in a filled and sealed bag (8) containing particulate solids materials such as powder, granules and flakes. The method has steps of the bag being loaded via its mouth (4) or acquiring the loaded open mouthed bag, extracting some of the gas or air from the bag using a gas extraction or vacuum apparatus (6) about which the mouth is at least substantially sealed, temporarily clamping or pinching (1) the mouth closed below the at least substantial seal with the gas extraction apparatus, and prior to release of the clamping or pinching, heat sealing the bag without allowing any substantial gas ingress. Also disclosed is a machine line with a zone for opening the bag using suction cups (1), inserting a gas extraction apparatus and extracting some of the air from a product loaded bag and another machine zone for sealing the bag.

Description

APPARATUS AND METHOD OF REDUCING GAS IN A FILLED AND SEALED BAG.

FIELD The present invention relates to the filling of containers (more specifically bag like containers), apparatus suitable for use in such filling and/or closure, containers (including bags) closed by such methods and/or apparatus, and packs having any of the characteristics hereinafter described.

BACKGROUND ART A frequently used form of container is that of a bag. A bag can take on a number of guises. It can be of a single or multiple plies and/or it can be of single or multiple materials. By way of example a frequently used bag assembly is that of "a bag within a bag" where the "inner bag" is of one or more heat sealable plastics plies whilst the "outer bag" is of one or more plies of a similar or different material. Frequently the "outer bag" is of a paper ply or of plies of paper. Many such bags are known and in this respect we refer you, by way of example, to

NZ Patent Specification Nos. 183617 and 242034. Irrespective of whether or not we are dealing with a bag within bag scenario or not, there is a need to effect closure after filling of the container with the material to be packed. In some situations (such as particularly with wicketed bags) air inflation might be utilised to allow the loading of contents whereupon thereafter the whole assembly prior to closure may be subjected to an ambient environment of a reduced pressure so as to minimise the amount of air or other gases to be trapped within the pack when closed. In other situations where a bag might be filled with a powder reliant upon a gravity fill procedure it is not unusual for a vacuum horn operating through a porous filtering matrix to be utilised to provide some semblance of settling of contents and air extraction prior to subsequent closure of the bag by any appropriate sealing method, whether a welding procedure or not. Most usually however closure is affected by heat, RF, acoustic or other sealing procedures that can operate through any outer bag should there be one present. Even so however such procedures have a cycle rate and/or still leave a good measure of ambient gas (usually air) trapped in the sealed bag. This trapped air can give rise to difficulties particularly where the pack is to be stacked. Where very little gas (e.g. air) is entrapped in a sealed container, particulate solids materials (e.g. powders, granules, flakes, etc) can readily assume a load bearing capability without placing undue stresses on the integrity of the surround of such contents provided by the closed bag. This is particularly important if bursting or the like is to be avoided in stacking or other situations. There is also the question not only of possible rupture owing to bursting under such static or dynamic loads as might be encountered but also the question of instability in stacking situations caused by any tendency to billow caused by entrapped gas. Several approaches have been adopted in the past to allow for venting but which otherwise leaves products more or less contained in the container. See for example US Patents 3302859, 4470153, 4550441, 6170985, 6214392, 6274181 and 6355078, New Zealand Patent Specification 286115 and PCT Publications WO01/12425 and WO03/078263. The present invention however wishes to approach the difficulty by ensuring that at the time of sealing there has been a reasonable measure of gas removal prior to sealing such that any limited amounts of gas still present are unlikely to cause difficulty in what is otherwise a fully sealed bag or bag within a bag. It is therefore an object of the present invention to provide methods and related apparatus, products and the like which will at least provide for an alternative to or an addition of the venting approaches disclosed previously by reference to the US, New Zealand PCT Publications.

DISCLOSURE OF INVENTION In a first aspect the present invention consists in a method of reducing gas in a sealed bag, which method comprises or includes the steps of: loading the bag via its mouth or other loading inlet (hereafter "mouth"), extracting at least some of the gas from the loaded bag using gas extraction apparatus about which the mouth is at least substantially sealed, and thereafter sealing the bag without allowing any substantial gas ingress, wherein the seal is of the bag below where said at least substantial seal with the gas extraction apparatus occurs. In another aspect the present invention consists in a method of reducing gas in a sealed bag, which method comprises or includes the steps of: loading the bag via its mouth or other loading inlet (hereafter "mouth"), extracting at least some of the gas from the loaded bag using gas extraction apparatus about which the mouth is at least substantially sealed, and thereafter sealing the bag without allowing any substantial gas ingress, wherein the bag is machine moved relative to the gas extraction apparatus in a machine line prior to sealing in the machine line. In another aspect the present invention consists in a method of reducing gas in a sealed bag, which method comprises or includes the steps of: loading the bag via its mouth or other loading inlet (hereafter "mouth"), extracting at least some of the gas from the bag using gas extraction apparatus about which the mouth is at least substantially sealed, temporarily clamping, pinching or the like ("clamping") the mouth closed below the at least substantial seal with the gas extraction apparatus, and thereafter, prior to release of said clamping, sealing the bag without allowing any substantial gas ingress. In any of the preceding forms of the present invention optionally but preferably means (e.g. suction means) is provided in the machine or machine line whereby the mouth of the loaded bag is presented open for insertion of said gas extraction apparatus. Preferably said gas extraction apparatus is such as to facilitate the at least substantially sealing of the mouth of the bag to a vacuum head or vacuum head assembly ("vacuum head") of such apparatus. Optionally said vacuum head may include a filtering medium in order to minimise intake of particular material. Preferably the means by which the mouth is at least substantially sealed is by movement under the action of hydraulics, pneumatics, solenoids and/or the like of appropriate clamping members. Preferably the sealing of the bag without allowing any substantial gas ingress is a heat seal or some alternative such welding such as RF, ultrasonic or the like welding. In some forms of the present invention the bag can be a bag within a bag form. Preferably the means by which the bag is sealed without allowing any substantial gas ingress includes a temporary clamping, pinching or the like ("clamping") of the mouth to a pinch closed condition below where the at least substantial seal with the gas extraction apparatus occurs prior to the release of said at least substantial seal and thereafter the

(permanent) sealing of the bag prior to release of said temporary clamping. Preferably said temporary clamping is by a pinch conveyor arrangement capable of allowing the bag when non pinching the bag, the stationing of the bag for insertion and/or removal of the gas extraction apparatus and, when pinching the bag, of moving the bag from a relatively with respect to the gas extraction apparatus to a sealing zone. Preferably a machine line provides for the sequenced operation of at leas the extraction of the gas and the sealing. Preferably the same machine line also deals with the loading of the bag. In another aspect the invention consists in apparatus for closing a product or produce containing bag, said apparatus having (i) indexed to a bag to be closed, machine controlled in bag gas withdrawal means, and (ii) indexed to a bag previously subject to the gas withdrawal means, machine controlled bag sealing means, wherein (A) there is provision for machine controlled bag movement without any substantial gas ingress between the indexed conditions (i) and (ii), and/or wherein (B) there is the prospect both the gas withdrawal means and the sealing means are operating on different bags at least substantially simultaneously. Preferably the apparatus operates as in (B) without any substantial gas ingress into the bag being sealed since the time of being subjected to gas withdrawal means. Preferably the apparatus operates as in (B), there being means to provide a pinch closure of each bag at least substantially up until its sealing. Preferably the apparatus operates as in both (A) and (B) [optionally with means to provide at least prior to sealing, pinch closure of each bag]. In some forms of the present invention preferably the arrangement is substantially as hereinafter described with or without reference to any one or more of the accompanying drawings. In another aspect the present invention consists in, in a machine line, a method of reducing the air inclusion in a bag, which method comprises or includes the steps of: at one machine zone or condition, extracting at least some of the air from a product loaded bag using gas extraction apparatus about which the mouth of the bag is at least substantially sealed, and at another machine zone or condition, thereafter sealing the bag without allowing any substantial air ingress. Preferably between the zones the mouth of the bag is pinch clamped. Preferably the pinch clamping is by a conveyor which alone or in concert with other means moves and/or allows bag movement between the zones. In another aspect the present invention consists in, in a machine line, a method of reducing the air inclusion in a bag, which method comprises or includes the steps of: (I) at one machine zone or condition, optionally opening the bag, inserting gas extraction apparatus of the machine line into the open bag and extracting at least some of the air from a product loaded bag using said gas extraction apparatus about which the mouth of the bag is at least substantially sealed, and (II) at another machine zone or condition, thereafter sealing the bag without allowing any substantial air ingress. Preferably between the zones the mouth of the bag is pinch clamped. Preferably the pinch clamping is by a conveyor which alone or in concert with other means moves and/or allows bag movement between the zones. Preferably in said machine line the method is a method as previously detailed. In another aspect the present invention consists in, in a bag sealing machine line, the provision of at least one (and preferably a pair of) endless conveyor(s) [or series thereof] which can be brought to bear on or off a bag such that, when "bearing on" a bag, it is able to move the bag between stations but, when "bearing off' the bag, it is able to allow the bag to station, firstly, at an air withdrawal station or,, secondly, at a bag sealing station yet which conveyor(s) [e.g. a belt or belts] is (are) able to provide a pinch effect on the bag so as to reduce air ingress between the stations into the bag. In yet a further aspect the present invention consists in a machine line adapted for performing a method in accordance with any aspect of the present invention. In yet a further aspect the present invention consists in apparatus for performing a method in accordance with the present invention, said apparatus including: the provision of a zone or station at which an open but loaded bag can have a gas extraction apparatus positioned to draw air from within the bag whilst the bag is held to itself and/or the gas extraction apparatus thereby to minimise air ingress and the provision of a zone or station whereby the bag, without allowing any substantial air ingress, can be sealed. Preferably said apparatus includes a pinched clamping provision that is maintained from prior to the withdrawal of the gas extraction apparatus and until after sealing. Preferably said pinched clamping provision is provided by a conveyor cammed or otherwise actioned to clamp or not clamp the bag. Preferably said conveyor is to move in concert with apparatus that is to assist in bag movement between the zones or stations. In still a further aspect the present invention consists in a bag sealed using a method in accordance with any aspect of the present invention, in a machine line in accordance with any aspect of the present invention or using apparatus according to any aspect of the present invention. In still a further aspect the present invention consists in, in a bag closing apparatus, the provision of a pinch clamp(s) (e.g. conveyor belt(s)) which move in synchrony with the bag after pinch clamping of the bag after at least some air withdrawal and/or expression therefrom thereby to maintain the still unsealed bag in a condition which prevents any substantial ingress of air into the bag prior to sealing. As used herein the term "and/or" refers to "and" or "or" or where appropriate both. As used herein the term "(s)" following a noun includes as might be appropriate the plural and singular forms of that noun. As used herein the term herein "mouth" in respect of a bag refers to any appropriate part of the bag that might be considered as providing access into the remainder of the bag i.e. towards the base of the bag. Reference to such terms as "below" or "above" with respect to a bag is by reference to a bag as if it is actually or notionally aligned with its mouth uppermost (i.e. irrespective of whether or not that is in fact a prerequisite in a specific statement of invention claim or description of that bag). Any orientation is within the scope of the present invention subject however to any loaded material not easily escaping from the bag via its mouth prior to sealing. Reference herein to "sealing" of the bag after the provision of a temporary seal

(e.g. by clamping) against the gas extraction apparatus is reference to a permanent form of seal that requires no ongoing machine attention in the machine line (e.g. is preferably a weld but could be any appropriate fold or other closure technique whether reliant upon welding, adhesives and/or penetrative or other fasteners). As used herein "zone" does not necessarily mean a "station". A station can be stationary with respect to the factory but alternatively can be moveable with respect to the factory provided it maintains at its operational time some register or synchrony with the bag. It is envisaged in some forms of the present invention a "zone" may include a single, multiple or continuous range of positions relative to a factory or other location and/or the bags.

BRIEF DESCRIPTION OF DRAWINGS The preferred form of the present invention will now be described with reference to the accompanying drawing in which Figure 1 is a flow diagram showing one preferred form of the present invention, Figure 2 is the arrangement of Figure 1 showing by reference to Zones I, II and III where it is envisaged that the machine line deals with each of the steps, Figure 3 is a perspective view of zone II apparatus in accordance with the present invention showing the gas extraction apparatus with its (preferably) boat hull shaped vacuum head retracted from a freshly presented bag that has been opened by the action on both panels at the mouth region by at least one (and preferably two sets) of vacuum cups ready to allow the vacuum head to be inserted, Figure 4 is the apparatus of Figure 3 showing the vacuum head inserted whereupon the vacuum cup support of the bag in an open condition would be released as vacuum is applied within the bag via the vacuum head thereby conforming the bag to the boat or other shape of the vacuum head alone and/or in conjunction with any other temporary clamping etc thereof there onto, Figure 5 shows the movement to the left from zone II to the zone III of the apparatus, the vacuum head having first been withdrawn following preferably clamping with pinch conveyor belts of the bag above the contents of the bag yet below the extent to which the vacuum head (in the condition as in Figure 4) had penetrated down into the opened bag, Figure 6A is a view from the feed in end of the zone II apparatus showing a pairing of belts moveable so as to provide a pinch clamping affect on a bag (not shown) from the condition shown in Figure 6A under the action of linkages from a pneumatic or hydraulic cylinder (preferably pneumatic), the belts when clamping having the effect of pinch clamping and preferably in part moving the bag from zone II to zone III, Figure 6B is a similar view to that of Figure 6A but showing the belts in their pinched clamping condition (no bag being shown for clarity of the diagram), Figure 7 is a view directly from below of the apparatus of Figure 6 showing how a pneumatic cylinder or RAM assembly acting on a linkage has the ability to move inwardly the wheels thereby to effect the pinch of one endless conveyor belt to move belt wise in synchrony with the other, Figure 8 shows, to the left of zone II, the zone III sealing apparatus that is to receive with the pinched belt and other support of the loaded and temporarily belt clamped bag the mouth region for heat sealing by any appropriate sealing apparatus at zone III, Figure 9A shows a perspective view of part of another embodiment of the present invention, the apparatus showing filter probes raised relative to a shown lowered lowerable vacuum head, _ _

Figure 9B is a similar view to that of Figure 9A but showing, in respect of the vacuum head in its lowered condition as in Figure 9A, the filter probes in a condition where they pass down into a bag (not shown), Figure 10A through 10E shows in respect of an embodiment using apparatus as in Figures 9A and 9B a pre-lowered (i.e. raised) condition (Figure 10A), a vacuum probe lowered condition (Figure 10B), a vacuum probe lowered condition in respect of the lowered vacuum head (as in Figure 10B) (Figure IOC), the raising of the vacuum probes (Figure 10D), and the return to the condition as in Figure 10A (Figure 10E), Figure 11 A is a view of the vacuum head lowered down as if in a bag notionally shown, the pinch bars being shown spaced apart from the bag, Figure 11B is a similar view as that of Figure 11A but showing the pinch bars pinching the bag so as to effect the substantial seal about the vacuum head of the bag and to continue that substantial seal to the extremities of the bag, and Figure 12 is a view from beneath apparatus, for example, as shown in Figures 9A through 1 IB but showing, below line AA and without depicting the belt about the idle and drive folders, the belt pressure roller gangs in an open condition which does not force the belt onto the bag so as to advance the bag, whilst the same drawing, above the line AA, shows the complement of gangs of belt pressure rollers in the condition they assume when forcing the belt (not shown) so as to advance a bag, of course the conditions shown above or below the line AA, in actual use, preferably being a mirror image of the other. In the preferred form of the present invention a bag is to be sealed after having been loaded with a pre-determined amount of a particulate material (that could be of any of the kinds hereinbefore described) or can indeed relate to other materials of a kind requiring some confirmation of at least part of the bag to itself and about the load by reduction of gas and air inclusion therein. As used herein reference to "air" should be considered synonymous with any ambient gas that may have been entrained into the bag or been in the bag during any loading stage. In the zone II arrangement it is envisaged the sequence will be as depicted in Figures 1 and 2 with a plurality of suction cups 1 on each side having the effect of pulling apart the panels 2 and 3 of the bag thereby to open the mouth 4 of the bag for subsequent insertion of the vacuum head 5 of the gas extraction apparatus 6. Since, by way of example, the bag depicted has lie flat front and rear panels 2 and 3 respectively (whether simply fold line connected or gusset connected at the edge) it is ideal that the vacuum head be elongated so as to not be a localised vacuum horn that might intrude down into the load of the bag or otherwise provide some degree of difficulty for bag conformity thereto. With the arrangement as shown in Figure 3 the vacuum head 5 is shown lowered into the open bag inside a vacuum head matching surround 7 with the capability that the bag conforms closely thereto (with or without any ancillary temporary clamping). It is envisaged however that lowering of the wedge like vacuum head 5 (which optionally includes a filtering medium therein to avoid particulate material uptake) effects its own substantial seal both internally and externally of the bag. The bag 8 itself can preferably also be supported at its lower end on a trolley, conveyor, bogie or the like which will synchronise incrementally or continuously its movement as required at its top (whether stationed or moving) so as to reduce the load bearing required at the top regions of the bag. In some forms however such an arrangement is unnecessary particularly where loads supporting bags of a multi-layer type are used (e.g. of one or more outer bag forming layers of, for example, a kraft paper, and at least one inner bag ply of a heat sealable thermoplastics film. In the arrangement as shown in Figure 5, the bag 8 is shown moving from zone II to zone III. During this time the bag is temporarily clamped shut by the action of the belts 9 as in Figures 6Aa and 7 under the action of the pneumatic ram assembly 10 that acts, via linkages 11, to move the wheels 12 inwardly to achieve the belt against belt effect through the pinch clamped bag (not shown). This differs from the more spaced apart condition as shown in Figure 6A where the belts 9 in their zone 13 at which a bag 8 is to be held (as in Figures 3 and 4) stationary with respect to the apparatus between what is preferably still the moving conveyor belts 9. Such belts when pinched will have the effect of at least assisting bag advancement from zone II into zone III whereupon there can again be an idling arrangement (e.g. by belt separation) provided there is an uptake of the temporary clamping effect by the heat sealing head or ancillary apparatus. Whilst in the preferred form of the present invention the sequence is preferably as shown in Figures 1 a person skilled in the art will appreciate how there may well be circumstances where a vacuum can be drawn which conforms the bag to the vacuum head without any ancillary clamping and provided there is some at least temporary sealing/clamping. _ _

As might be appreciated, clamping closed of the bag above the contents so that the vacuum head can be withdrawn without any substantial gas ingress is preferably below the vacuum head when it is in its condition as shown in Figure 4. In the preferred form of the present invention the method of temporary clamping closed of the bag at both zone II and zone III is by the same endless belt conveyor or paired belt conveyors. It could be otherwise. Also carousel and other arrangements may well be gas extraction apparatus and then bag sealing apparatus to bags but with preferably the facility that at the time the gas extraction apparatus acts on one bag the sealing apparatus acts on another. It is believed that a high rate of throughput with an arrangement with the present invention is possible. The present invention by separating the functions into two zones or stations (i.e. gas removal and sealing) is believed to allow milk powder and other particulate containing bags to be passed through the apparatus at about or at least 700 bags per hour which is considered well in excess of that available from existing apparatus if there is to be good load contouring of the bag. In Figures 9 A and 10 there is shown the gas extraction head 14 capable of being moved from a raised condition (not shown) to the lowered condition shown in each of Figures 9 A and 9B. Mounted so as to be lowerable relative to such apparatus 14 are gas extraction probes 15 preferably of a porous stainless steel (e.g. a sintered stainless steel) and arranged when lowered in the condition shown to have a vacuum through them so as to extract gas from within the bag. In preferred forms the bag will have a plastics pouch and it is from this plastics pouch located reproducibly relative to usually a paper or composite outer bag that the attention is given as far as gas extraction is concerned. Figures 10A through 10E show a cycle of the gas extraction head 14 in a raised condition (Figure 10A) through to its raised condition for the start of a fresh cycle (Figure 10E). In between that it is lowered to the condition shown in Figures 10B, C and D whilst in the phase as shown in Figure 10C the gas extraction probes 15 are lowered as has already been shown in Figures 9B. Throughout this arrangement the bag 16 is held clamped upon itself for at least stage 10C (for this purpose) not actually shown in Figure 10C but demonstrated by Figure 1 IB pinch bars 17 are caused by the pneumatic ram 18 to provide the substantial seal. Shown in Figures 10A through E and 11A and 11B is an arrangement of mounts, pivots and linkages such as alternatively can be used in preference to those shown in the earlier figures. Figure 12 shows below the line AA two gangs 19 and 20 of rollers adapted when in the condition as shown above the line A (19A and 20 A) to bear upon the conveyor belt (not shown) so as to cause the belt to grip the bag and provide advancement in the conveyor belt moving direction. For clarity in Figure 12 the endless belts have not been shown but the drive and idle rollers have been. The linkages operable under pneumatic rams 21 and 21 A allow the movement of the roller gangs as disclosed. In a preferred form of the present invention the sequence of operation involves a filled bag supported by its base on a conveyor having its open end engaged into apparatus of the present invention at an appropriate level as which that end will be kept throughout the sequential steps. The following step is the opening of the bag and the insertion of the gas extraction apparatus whereupon there is then the substantial seal against the gas extraction apparatus at which stage the gas extraction probes withdraw unwanted gas from within the bag. Optionally there then follows as the bag is advanced still with its open end at the same level a cleaning (e.g. by blowing) of adhesive, heat seal and/or the like surfaces (e.g. of a pouch if a pouched bag in bag system) by removal of powder to ensure comprehensive seal. Throughout however the bag being clamped closed to prevent any substantial reintroduction of gas. There then follows a heat sealing stage whereupon no gas thereafter can enter the bag. With the bag preferably being of a kind with a thermoplastics pouch or inner liner of an outer bag there then follows preferably a closing stage preferably using a heat activatable adhesive of the bag and a turn over or pinching of the outer bag. Conventional apparatus for open end bag levelling, heat sealing and/or outer bag closure can be used. Typical of such conventional apparatus is that that hitherto has been supplied commercially by Technopak Limited.

Claims

CLAIMS:

1. A method of reducing gas in a sealed bag, which method comprises or includes the steps of: loading the bag via its mouth or other loading inlet (hereafter "mouth"), extracting at least some of the gas from the loaded bag using gas extraction apparatus about which the mouth is at least substantially sealed, and thereafter sealing the bag without allowing any substantial gas ingress, wherein the seal is of the bag below where said at least substantial seal with the gas extraction apparatus occurs.

2. A method of reducing gas in a sealed bag, which method comprises or includes the steps of: loading the bag via its mouth or other loading inlet (hereafter "mouth"), extracting at least some of the gas from the loaded bag using gas extraction apparatus about which the mouth is at least substantially sealed, and thereafter sealing the bag without allowing any substantial gas ingress, wherein the bag is machine moved relative to the gas extraction apparatus in a machine line prior to sealing in the machine line.

3. A method of reducing gas in a sealed bag, which method comprises or includes the steps of: loading the bag via its mouth or other loading inlet (hereafter "mouth"), extracting at least some of the gas from the bag using gas extraction apparatus about which the mouth is at least substantially sealed, temporarily clamping, pinching or the like ("clamping") the mouth closed below the at least substantial seal with the gas extraction apparatus, and thereafter, prior to release of said clamping, sealing the bag without allowing any substantial gas ingress.

4. A method of any one of claims 1 to 3 wherein a suction device in the machine or machine line present the mouth of the loaded bag open for insertion of said gas extraction apparatus.

5. A method of any one of the preceding claims wherein said gas extraction apparatus is such as to facilitate the at least substantially sealing of the mouth of the bag to a vacuum head or vacuum head assembly ("vacuum head") of such apparatus.

6. A method of claim 5 wherein said vacuum head includes or is associated with a filtering medium in order to minimise intake of particular material.

7. A method of any one of claims 1 to 6 wherein the mouth is at least substantially sealed under the action of hydraulic, pneumatic, solenoid and/or the like driven clamping members.

8. A method of any one of the preceding claims wherein the sealing of the bag without allowing any substantial gas ingress is a heat seal or some alternative such welding such as

RF, ultrasonic or the like welding.

9. A method of any one of the preceding claims wherein the bag is of a bag within a bag form.

10. A method of any one of the preceding claims wherein the means by which the bag is substantially sealed without allowing any substantial gas ingress includes a temporary clamping, pinching or the like ("clamping") of the mouth to a pinch closed condition below where the at least substantial seal with the gas extraction apparatus occurs prior to the release of said at least substantial seal and thereafter the (permanent) sealing of the bag prior to release of said temporary clamping.

11. A method of claim 10 wherein said temporary clamping is by a pinch conveyor arrangement capable of allowing the bag when non pinching the bag, the stationing of the bag for insertion and/or removal of the gas extraction apparatus and, when pinching the bag, of moving the bag from a relatively with respect to the gas extraction apparatus to a sealing zone.

12. A method of any one of the preceding claims a machine line moves the bag from where there is the extraction of the gas to where there is the sealing of the bag.

13. Apparatus for closing a product or produce containing bag, said apparatus having (i) indexed to a bag to be closed, machine controlled in bag gas withdrawal means, and (ii) indexed to a bag previously subject to the gas withdrawal means, machine controlled bag sealing means, wherein (A) there is provision for machine controlled bag movement without any substantial gas ingress between the indexed conditions (i) and (ii), and/or wherein (B) there is the prospect both the gas withdrawal means and the sealing means are operating on different bags at least substantially simultaneously.

14. Apparatus of claim 13 wherein the apparatus operates as in (B) without any substantial gas ingress into the bag being sealed since the time of being subjected to said gas withdrawal means.

15. Apparatus of claim 13 or 14 wherein the apparatus operates as in (B), there being means to provide a pinch closure of each bag at least substantially up until its sealing.

16. Apparatus of claim 13, 14 or 15 wherein the apparatus operates as in both (A) and (B) [optionally with means to provide at least prior to sealing, pinch closure of each bag].

17. In a machine line, a method of reducing the air inclusion in a bag, which method comprises or includes the steps of: at one machine zone or condition, extracting at least some of the air from a product loaded bag using gas extraction apparatus about which the mouth of the bag is at least substantially sealed, and at another machine zone or condition, thereafter sealing the bag without allowing any substantial air ingress.

18. A method of claim 17 wherein between the zones the mouth of the bag is pinch clamped.

19. A method of claim 18 wherein the pinch clamping is by a conveyor which alone or in concert with other means moves and/or allows bag movement between the zones.

20. In a machine line, a method of reducing the air inclusion in a bag, which method comprises or includes the steps of: (I) at one machine zone or condition, optionally opening the bag, inserting gas extraction apparatus of the machine line into the open bag and extracting at least some of the air from a product loaded bag using said gas extraction apparatus about which the mouth of the bag is at least substantially sealed, and (II) at another machine zone or condition, thereafter sealing the bag without allowing any substantial air ingress.

21. A method of claim 20 wherein between the zones the mouth of the bag is pinch clamped.

22. A method of claim 21 wherein the pinch clamping is by a conveyor which alone or in concert with other means moves and/or allows bag movement between the zones.

23. In a bag sealing machine line, the provision of at least one endless conveyor or series thereof which can be brought to bear on or off a bag such that, when "bearing on" a bag, it is able to move the bag between stations but, when "bearing off' the bag, it is able to allow the bag to station, firstly, at an air withdrawal station or,, secondly, at a bag sealing station yet which conveyor or series thereof is (are) able to provide a pinch effect on the bag so as to reduce air ingress between the stations into the bag.

24. Apparatus of claim 23 wherein there is a pair of endless conveyors or series thereof.

25. Apparatus for performing a method in accordance with any one of claims 1 to 12 and 16 to 22, said apparatus including: the provision of a zone or station at which an open but loaded bag can have a gas extraction apparatus positioned to draw air from within the bag whilst the bag is held to itself and/or the gas extraction apparatus thereby to minimise air ingress, and the provision of a zone or station whereby the bag, without allowing any substantial air ingress, can be sealed.

26. Apparatus of claim 25 which includes a pinch clamping provision that is maintained from prior to the withdrawal of the gas extraction apparatus and until sealing or other pinch clamping is imposed through to sealing.

27. Apparatus of claim 26 wherein the or a pinch clamping provision is provided by a conveyor actionable to clamp or not clamp the bag.

28. Apparatus of claim 27 wherein the conveyor is to move in concert with apparatus that is to assist in bag movement between the zones or stations.

29. A bag sealed using a method in accordance with any one of claims 1 to 12 and 16 to 22 in a machine line in accordance with claim 23 or 24 or using apparatus according to any one of claims 13 to 16 and 25 to 28.

30. In a bag closing apparatus, the provision of a pinch clamp(s) which move in synchrony with the bag after pinch clamping of the bag after at least some air withdrawal and/or expression therefrom thereby to maintain the still unsealed bag in a condition which prevents any substantial ingress of air into the bag prior to sealing. 30. Apparatus of claim 29 wherein the pinch clamp(s) are a pair of conveyor belts or paired conveyors.