GB2078654A

GB2078654A - Loading plastics bags for packaging purposes

Info

Publication number: GB2078654A
Application number: GB8020752A
Authority: GB
Original assignee: WR Grace and Co
Current assignee: WR Grace and Co
Priority date: 1980-06-25
Filing date: 1980-06-25
Publication date: 1982-01-13
Also published as: FR2485480A1; IT1205249B; IT8122420A0; FR2485480B1; BR8103874A; GB2078654B

Abstract

A process of packaging articles in bags (9) involves feeding of a supply of side-sealed bags, at least partially connected to one another and with their mouths facing laterally, to a loading station in the form of a continuous chain. A set of article loading chutes (10a ... 10e) is provided at the loading station and includes means for gripping one side of each bag mouth located at the loading station so that the bags can initially be attached to the various loading chutes by operation of the gripping means and these loading chutes can then be brought together into a closely spaced configuration allowing the bags to billow upwardly upon exposure to an inflation air curtain. The bags can then be loaded with, for example, cylindrical sausages or cheeses and the loading chutes 10a... 10e then separated in order to spread the bags and to partially close the bag mouths ready for wrinkle-free sealing which is carried out when the bags, on a conveyor belt, are indexed into a vacuum chamber area. <IMAGE>

Description

SPECIFICATION Process and apparatus for loading plastic bags for packaging purposes, and package formed by use of same The present invention relates to a packaging process and apparatus, more particularly for packaging articles in side-sealed bags. The invention also provides a package formed by use of such a process and/or apparatus.

In the field of packaging articles such as food products, it has long been known to load the products into a bag, for example a bag of plastics material, through the mouth of the bag and then to seal the mouth of the bag. In the case of plastics bags, it is also known to carry out the sealing operation in a vacuum chamber where the residual atmosphere within the bag can be withdrawn and the package sealed under vacuum conditions in order to avoid deterioration of the food product in the sealed bag.

U.S. Patent No. 3,161,347 provides a disclosure of such a bag loading process and apparatus and illustrates the use of a chain of bags in imbricated form supported on a continuous support member so that the imbricated bags arrive at a loading station where the uppermost bag is pneumatically inflated and has a product article placed therein, after which the bag is removed from its elongate support member and delivered ready for subsequent advance to a bag closing station.

The present invention aims to provide a packaging system which is capable of more rapid and economic operation for loading articles into bags which are fed to a loading station in the form of a chain of bags, and the process is intended to enable the packaging operation to be speeded up.

Accordingly, the present invention provides a packaging process comprising providing a chain of side-sealed packaging bags with the mouths of the bags facing laterally of the chain of bags, feeding said chain of bags to a loading station, inflating the bags at the loading station, loading a product article into each bag, and advancing the loaded bags to a bag closing station. Preferably the bags remain attached to one another during loading and bag closing. More preferably several of the bags are loaded in a batch and the bag of that batch is then closed simultaneously with one another.

The present invention also provides a packaging apparatus comprising a bag loading station including a plurality of product loading chutes; means for advancing a chain of sidesealed bags to said product loading chutes while the bags are still attached to one another along at least a part of their side-sealed edges; means for holding each of said bags alongside a respective one of said product loading chutes at the loading station; means for moving the various product loading chutes towards and away from one another at the loading station so as to vary the spacing between adjacent ones of said chutes and to facilitate billowing of the bags during bag loading; means for opening the individual bags held adjacent said associated product loading chutes; and means for closing the bags after loading.

The invention furthermore provides a package formed by the above process and/or by use of the above apparatus.

in order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a top plan view of a bag-loading and -closing apparatus in accordance with the present invention; FIGURE 2 is a side elevational view of the apparatus of Figure 1 as viewed along the direction of the arrow thereof; FIGURE 3 is a view similar to Figure 2 but showing the bags in an inflated configuration ready to receive product articles therein; FIGURE 4 is a detail top plan view illustrating the apparatus in the Figure 3 configuration; FIGURE 5 is a sectional view taken on the line V-V of Figure 2; and FIGURE 5a is a detail of Figure 5 but showing an alternative form of gripper closing spring.

Referring now to the drawings, there can be seen in Figure 1 an overhead view of a packaging apparatus comprising a vacuum chamber 1 and a loading table 2 at which two operators 3 work at respective bag loading stations to load bags with product articles which are supplied by respective product feed conveyors 4 fed from a main conveyor 5.

Connecting the loading station 2 and the vacuum chamber 1 is a conveyor belt 6 the upper run of which can be seen in Figure 1. The conveyor belt 6 includes reaction bars 7 in the form of heatresistant flexible strips which assist in the bagloading and bag-sealing process in a manner which will be described below. However, suffice it to say for the moment that on the underside of the hood defining the vacuum chamber 1 are counterpressure strips which include resistance heaters to apply heating impulses in order to seal the bag mouths as they are pressed between the counterpressure strips of the hood and the reaction strips 7 of the conveyor belt 6.At the righthand side of Figure 1 , the conveyor belt 1 can be seen as emerging from under a bag feeding unit 8 which supplies a chain of side-sealed preperforated bags, preferably of multi-layer construction, suitable for use in vacuum packaging of food articles.

The apparatus illustrated schematically in Figure 1 can, for example, be used for packaging continental sausages or elongate cheeses.

The process in accordance with the present invention relies on the use of a plurality of bags fed laterally to the loading station and loaded simultaneously or substantially simultaneously.

This operation will more readily be understood by reference to Figures 2 and 3 which show the bagholding and bag-loading apparatus as viewed along the direction of arrow II of Figure 1.

Each of the operators 3 in Figure 1 may be fed with a respective chain of bags arranged such that the bags are at least partially connected together along their lateral edges and therefore form a continuous web with the bag mouths facing laterally of that web. Each of the operators 3 may be presented with a respective such web, or if desired a double web may emerge from the bag feeding unit such that along each margin of the web there is an array of bag mouths of a respective set of bags presented for loading with articles by use of the present process, and along a longitudinal line between the two margins of the chain the bags may be closed by heat sealing, with a perforation line extending between the seal line defining the closed ends of the bags of one said set and the separate parallel seal line defining the closed ends of the bags of the other set.

The chain of bags is advanced by the operator and is laid on the reaction strip 7 prior to gripping by suitable gripper jaws 18 to be described below with reference to Figure 5.

It should be understood that the preferred construction of bag for use with the present invention has one of its faces longer than the other so that the longer face presents a lip which can readily be clamped by the above-mentioned gripper jaw 1 8 while the other face is shorter and can be lifted upon bag opening to define a mouth such that, while the longer face is held by the gripper jaw underneath a respective one of an array of product loading chutes 10....1 Oe, the bag mouth will not foul that product loading chute or the article being fed therefrom.

Although, as indicated above, the operator 3 may be relied upon to arrange the line of bags 9a ... 9e of the chain along the reaction strip 7 of the conveyor belt 6, it is of course conceivable for some automatic or semi-automatic feed mechanism to be provided, if desired. One such feed mechanism may, for example, comprise a holding unit 11 (schematically illustrated in Figure 4) which can be operated to grip and to hold the leading edge of the chain of bags such that as the conveyor belt 6 advances to pass the previously loaded batch of bags 9a ... 9e into the vacuum chamber, the leading edge of the remainder of the bag chain is simultaneously drawn forward already in position on the next reaction strip 7, for loading in the next bag-loading operation.

Initially, when the chain of bags is in place on the conveyor belt 6, the bag chain is in a relatively flat configuration and is also relatively taut.

The loading apparatus in this case provided with five products loading ramps 10a, 1 Ob, 1 Oc, 1 Od, and 1 Oe which initially are spaced apart at substantially the same pitch as the pitch of the bags in the chain.

An inflation air curtain, emanating from a nozzle which will be described in more detail below with reference to Figure 5, serves to begin inflation of the bags and the partially inflated state of the bags can be appreciated from Figure 2. The various product loading chutes 1 Oa . . . 1 Od are then moved rightwardly to a second configuration shown in Figure 3 where they are all much closer together to one another and to the last product loading chute 1 owe. In the second configuration, the penultimate product loading chute 1 Od is closely adjacent the final and stationary product loading chute 10e, the next preceding chute 1 Oc is closely adjacent the penultimate chute 1 Od, and so on. In this particular configuration the spacing of the product loading chutes 1 Oa . . . 1 Oe is less '.

than the pitch of the bags and consequently the bags are able to billow upwardly to an extent even greater than that illustrated in Figure 3 and in that configuration they are able to accept product articles of circular cross-section such as continental cheeses which can be placed on the product loading chutes 1 Oa ... 1 Oe and then be simultaneously or substantially simultaneously advanced from the set of product loading chutes 10a ... Oe into the individual, opened bags.

Once the bags have been loaded, the various product loading chutes 1 Oa ... 1 Od are again moved leftwardly to their first configuration (illustrated in Figure 2) so that the original spacing between the five loading chutes has been restored: in that second configuration the chutes are once again at substantially the same pitch as the arrangement of the bags along the chain. In this configuration the mouth of each bag will be partially closed and in a wrinkle-free configuration whereas the main body of the bag will of course be bowed upwardly by the presence of the product article in the bag.

During or before this bag mouth spreading operation, the operator will have severed the bag 9a held by the gripper under the product loading chute 1 Oa from the remainder of the chain of bags, and consequently at the end of the bagspreading operation during which the various product loading chutes return to the Figure 2 configuration the gripper jaws 1 8 (Figure 5) under the tips of the product loading chutes can then release the various bags to allow the conveyor belt 6 to index forwardly to carry the individual product articles in their bags into the vacuum chamber 1, it being understood that the hood of the vacuum chamber will have been raised to allow discharge of the previously evacuated and sealed set of bags as the next set of loaded but unsealed bags is introduced by the indexing movement of the conveyor belt 6.

Where, as indicated above, the reaction strips 7 are provided with a bag chain holding unit 11, it is necessary for the operator, after having severed the batch of five attached bags 9a, 9b, 9c, 9dand 9e from the leading end of the remainder of the chain of bags, simply to attach the leading corner of that remainder of the chain to the holding unit 11 of the next successive reaction strip 7 on the conveyor belt in order to ensure that when the conveyor belt 6 indexes to drive the now loaded bags 9a ... 9e into the vacuum chamber the next five bags will automatically be drawn across in front of the product loading chutes 10a . . . 1 Oe ready for loading and subsequent sealing.

The apparatus illustrated in Figures 2 to 4 is particularly advantageous in its operation, by virtue of the successive drawing together of the product loading chutes 10....1 Oe for the loading operation and then re-spreading of the chutes to flatten the batch of bags 9a ... 9e for partial closing of the bag mouths before the evacuation step.

When the five bags 9a ... 9e are moved laterally on their journey into the vacuum chamber 1, the fact that the bags 9a ... 9e are still attached to one another prevents any rolling of the cylindrical product articles and consequently ensures that the bag mouths are still in a relatively flat configuration by the time the hot-welding counter strip (not shown) in the underside of the hood comes to press against the mouths of the bags on the reaction strip 7 of the conveyor belt.

As shown in Figures 2 and 3, the various product loading chutes 10a ... 1 Oe are each provided with a downwardly extending bracket 12a...12e having two pegs 13 and 14 thereon.

These pegs serve to facilitate connection to respective straps 1 5 which have one end 1 spa drilled with a hole to receive one of the two pins 13 and 14 and the other end provided with a longitudinally extending slot 16 to receive the other of the two pins of another of the brackets 12a...12e. As can be seen clearly by comparing Figures 2 and 3, when the five product loading chutes 1 Oa . . . 1 Oe are in their widely spread configuration, the peg which engages in the slot 16 is at the end of the strap 15 remote from the end 15a.On the other hand, when the five product loading chutes 1 Oa ... 1 Oe are in their closely spaced configuration the same pin has traversed the length of the associated slot 16 to arrive at the end nearer the end 1 5a of the strap 1 5.

A suitable quick release fitting will be provided on each of the pegs 13 and 14 so that it is an easy matter to remove some of the product loading chutes 1 Ob, 1 Oc and 1 Od, or to insert additional product loading chutes. This removal and replacement operation will of course require the use of different straps 15 in order to ensure that the correct traverse length of the respective product loading chutes 10.... 1 Od with respect to the stationary product loading chute 1 Oe is provided for. Clearly, where six product loading chutes are provided it will be necessary for the traverse length to be reduced if the same drive ram 17 is to be capable of stroking the left most product loading chute 1 Oa between its Figure 2 position and its Figure 3 position.

In practice, bearing in mind that a different number of product loading chutes will correspond to a different pitch of bag spacings and hence to a different bag width which will require a different value of the difference in width between its inflated position (Figure 3) and its spread position (Figure 2), it is expected that the stroke of the ram 17 can be substantially constant and thus all that needs to be changed during adaptation from one bag pitch value to another bag pitch value is simply the addition or removal of one or more product loading chutes 1 Oa ... 1 Oe and the exchange of one set of straps 15 for another.

The sets of straps will be coded in some way so that it is an easy matter for the operator to identify the appropriate set of straps to match a particular number of product loading chutes to correspond to a particular value of the bag pitch.

Reference to Figure 5 will now serve to illustrate the way in which the individual product loading chutes 10a ... 1 Oe are operated synchronously for opening and closing of the gripper jaw 18 and for sliding movement of the product loading chute 10 along two parallel cylindrical rails 19 and 20.

The above description with reference to Figures 2 to 4 has indicated that the various product loading chutes 10....1 Od are capable of moving laterally between the Figure 2 or first configuration where the bags 9a ... 9e are spread relatively flat and the product loading chutes 1 Oa ... 1 Oe are in their widest apart configuration, and the Figure 3 or second configuration where, by virtue of the product loading chutes 1 Oa .. . 1 Od having come together, the various bags 9a ... 9e are capable of billowing upwardly to a greater extent. This lateral movement of the product loading chutes 1 Ova .. 1 Od is provided for by an ability of the support block 21 of the product loading chute (10e in Figure 5) to slide along the rails 19 and 20, under the action of the drive ram 17 (Figure 2). The linkage between the various product loading chutes 10a ... 10e has been illustrated in Figures 2 and 3 and is omitted from Figure 5, for the purposes of clarity.

Extending parallel to the two rails 19 and 20 is a rotatable cam shaft 22 which supports a cam rod 23 by means of a set of struts 24 extending radially of the cam shaft 22. Throughout movement of the support block 21 of the product loading chute 1 owe along the rails 19 and 20, a cam follower surface 25 of a rearward extension of the gripper jaw 18 rests above the cam rod 23 such that when the cam shaft 22 is rotated through an incremental angie, in the clockwise direction as viewed in Figure 5, the cam rod 23 lifts to open the gripper jaw 18.This same cam rod 23 engages the cam follower surfaces 25 of each of the other gripper jaws 18 and the arrangement is such that the reduction or increase in the number of product loading chutes in order to accommodate a different bag pitch will require no additional adjustment in order to ensure engagement of the cam system 22-24 because of the continuous nature of the cam rod 23.

As shown in Figure 5, the support block 21 for the product loading chute 10 has a front forwardly open recess 26 to facilitate removal of the support block 21 from the front rail 20 and its reattachment when required. Similarly, at the rear of the support block 21 is a downwardly open recess 27 to ensure that once the front recess 26 has been engaged with the front rail 20 the rear of the product loading chute can be lowered to bring the rear recess 27 into engagement with the rear rail 19. Some locking means (not shown), which may for example comprise a plate pivotally attached to the underside of the support block 21 so as to be rotated into a position in which it effectively closes the downwardly open mouth of the rear recess 27, may be incorporated in order to ensure that the product loading chute 1 Oe is firmly held on the two rails 1 9 and 20.

Behind the row of product loading chutes is a forwardly curved deflector plate 28 at the upper end of a convergent inflation air passageway 29 which extends along the full length of the loading station (i.e. the full length of the zone occupied by the various product loading chutes 10a ... 1 Oe in their Figure 2 configuration) and is connected to a blower (not shown) lower down on the apparatus near the floor. A secondary air passageway 30 is provided just in front of the convergent passage 29, so as to make it possible for additional airflow to be entrained at the corner of the deflector plate 28 by the high speed air curtain emanating from the passageway 29.As a result, when the fan is energised the various product loading chutes will be in register with the horizontal leftwardly moving curtain of inflation air which will pass along the product loading chutes and into the bags to inflate them.

One such bag 9e is shown in Figure 5 and has its lower lip 30 clamped by the gripper jaw 18 and its upper face 31 supported by the pressure of the inflation air entering the bag mouth 32. At this time, a suitable product article (which may be of cylindrical form) will be placed on the product loading guide 1 Oe ready for insertion into the bag 9e, but for the purpose of clarity this has been omitted from Figure 5.

It will of course be appreciated that the various gripper jaws 18 will be spring-biased into their closed position, to be opened by the up-thrust of the cam rod 23 on the cam follower surface 25. In the embodiment shown in Figure 5, a torsion spring (not shown) will be positioned at the pivot spindle 33 of each gripper jaw 18. However, in an alternative embodiment it is possible for the biasing spring to be a coil compression spring between the upper side of the plate forming the cam follower surface 25, and the underside of the product loading chute 10 itself. Such an arrangement is shown in chain-dotted lines in Figure 5a.

The operation of the apparatus illustrated in Figures 1 to 5 will readily be understood from the above description of the construction of the apparatus as a whole, and the detailed description of the movement of the various product loading chutes 1 Oa ... 1 Oe between the Figure 2 and Figure 3 positions.

The present invention offers considerable advantages over any prior art bag loading process in packaging, because of the simplified presentation of the side-sealed bags drawn to the loading station from the bag feed unit 8 of Figure 1.

Other advantages which can be attributed to this particular embodiment of the present invention include the following:- The automatic feeding of a supply of sidesealed perforated bags to a loading station requires the absolute minimum of intervention by the operator who simply needs to arrange the bags on the reaction strips 7. (In a more sophisticated version of the apparatus it may be possible for the operation of attaching the bags to the reaction strips to be completely automated, thereby allowing the operator to concentrate on the smooth operation of the apparatus as a whole and not requiring any detailed intervention by the operator.) Secondly, the loading of several bags simultaneously increases the effectiveness of the evacuation operation since it is now possible to ensure that several bags are sealed simultaneously in the one vacuum chamber, without the need for a delay while the operator arranges a plurality of discrete bags on the reaction strips 7 before indexing of the conveyor belt to bring those bags into the vacuum chamber.

Thirdly, the ability to vary the number of product loading chutes 1 Oa ... 1 Oe enables the machine to be very rapidly and simply converted for different bag pitch values.

Fourthly, the ease of removability of the product loading chutes 1 Oa ... 1 Oe facilitates replacement of one set of product loading chutes by another which may be more suitable for a different product shape.

Fifthly, the fact that the apparatus includes two sets of reaction strips 7 on opposite margins of the conveyor belt allows two product lines to be packaged simultaneously, either where the product articles in each of the two lines are identical, or where the product articles of one line are different from those of the other line. In each case the most effective use of the energy dissipated in evacuating the interior of the chamber 1 is made.

Sixthly, because the bags are still at least partially attached to one another as the loaded bags are introduced into the vacuum chamber 1 on the indexing conveyor belt 6, there will be no rolling of even a fully cylindrical product article and consequently the arrangement of the articles in the chamber can be used to full advantage in that the maximum number of loaded bags may be used without risk of rolling causing one or more of the loaded bags at the end of the array from being trapped between the nearer transverse wall of the chamber and the conveyor belt as the chamber closes.

Furthermore, because of the closing together and separating movement of the various product loading chutes 1 Oa ... 1 Oe, resulting in firstly bunching and then re-spreading of the bags 9a ... .9e, the maximum possible efficiency of bag opening is provided for in that the upper walls 31 (Figure 5) of the bags are allowed to billow upwardly to the maximum extent during loading and nevertheless the bag mouth is then partially closed and neatly arranged for wrinkle-free sealing before the various bags are released by the gripper jaws 18 and indexed into the vacuum chamber 1.

As compared with any desirable use of the process with manual placing of bags on the conveyor belt, the preferred forms of the process and apparatus ensure that because the individual bags of the batch are all attached to one another in a batch extending along substantially the full length of the reaction strips 7 (defining the length of the vacuum chamber 1) there is no wasted space whatsoever and maximum utilisation of the length of each reaction strip for wrinkle-free sealing is achieved. This assists in ensuring the maximum utilisation of vacuum energy in that the batches of bags are as large as possible for a given vacuum chamber length.

The finished packages leaving the vacuum chamber may still be attached to one another at at least the mouth portion, so as to facilitate their immediate loading into a shrink tunnel or shrink bath. However, automatic means for separating the individual packages from one another may be desired.

In some applications, it may be preferable to leave the packages attached to one another in sets of say five products, for ease of handling at the consumer location (for example in Supermarkets where a discount rate for bulk purchase of the product articles may be offered).

Finally, the apparatus can either be fully automatic with a predetermined timing which can only be interfered with by the operator pressing a "panic button" when an interruption to the sequencing is required, or time to index only on the "all clear" instruction given by the operator.

In the above description of the operation of the product loading chutes, it has been assumed that the various product loading chutes 1 Ob ... 1 Od will be compietely removed from the machine when the number of product loading chutes is reduced. However, because the righthand product loading chute 1 Oe is stationary and it is the various other chutes 10.... .10which move relative to it, it is possible for one or more spare product loading chutes to be "parked" at the lefthand side of Figures 2 to 4, already threaded on the rails 1 9 and 20, ready for sliding into the loading station when additional parked loading chutes are required.These parked product loading chutes may even be completed with their own straps 1 5 to facilitate driving interconnection between the product loading chutes as they are brought into operation.

The above description is concerned with one particular embodiment of the present invention and is capable of modification within very wide limits as defined by the following claims. For example, the various individual straps 1 5 shown in Figures 2 and 3 may be replaced by an alternative mechanism for ensuring variable but reliable spacing of the product loading chutes 1 Oa . ..1 Oe as the lefthand product loading chute 1 Oa is reciprocated by the ram 1 7. For example, each of the product loading chutes 10a ... 1 Od may be provided with means for interconnecting it to a continuous coil spring extending between the lefthand chute 1 Oa and the stationary righthand chute 1 Oe such that, as the spring is extended, the various product loading chutes move apart with a constant but uniformly increasing spacing and then move together again as the coil spring is contracted. This arrangement also lends itself to the ease of insertion and removal of product loading chutes 1 Ova .. 1 Od and, to facilitate this, it may be advantageous to mark such a coil spring with various different indicia to indicate where the product loading chutes are to be connected when different numbers of chutes are required.

As explained above, the stroke of the ram 1 7 is substantially constant regardless of the number of product loading chutes in use and of the bag pitch.

In practice the stroke of the ram 17 is related to the length of the vacuum chamber 1, measured in a direction along the path of movement of the upper run of the conveyor belt 6.

Although not explained in detail above, the loading of product articles into the opened bags 9 can be achieved by a manual process in which the operator individually places product articles on the various product loading chutes 1 Oa ... 1 Oe and then simultaneously advances them all into the inflated bags (for example by means of one elongate pusher element which when it extends in the direction of movement of the belt 6 is long enough to engage product articles on each of the various product loading chutes 10....1 Oe).

Alternatively, a semi-automatic system may be available in which the operator charges each of the product loading chutes manually and the operation of delivering the articles from the product loading chutes is carried out by an automatically driven loading bar such as the above-mentioned manually operating loading member, in order to ensure that minimum time is wasted during the bag loading phase. The third possibility is for the individual product loading chutes to be loaded fully automatically (for example by means of overhead product guides fed from a common conveyor system). This may involve rather more sophistication in adapting the configuration of the overhead product guides for the location and number of the product loading chutes in operation for any particular bag pitch value, but is well within the scope of the expert in this art.

Although, as described above, the chamber 1 operates as a vacuum chamber, it is of course possible for the chamber instead to incorporate flushing gas injection means so that the packages can be sealed not under vacuum, but instead under an inert gas atmosphere. This possibility is made much easier by virtue of the precise positioning of the bags on the reaction strips 7, and the interconnection of the various bags preventing rolling of the articles during conveyor indexing.

The various bags may, as indicated above, be of multi-layer construction, for example so as to include both an oxygen barrier layer and a heat sealable layer to facilitate the sealing operation.

An optional abuse-resistant further layer may also be provided.

-The preferred form of the process in accordance with the present invention uses bags which are at least partially separated but left attached by perforations at the mouth end and at the closed ends of the bag. However, it is conceivable for the bags to be fully attached by means of a continuous perforation line (without the partial severing indicated in Figure 4) or for the bags to be fully detached from one another at the closed end so that only the mouth end is left attached to the next bag.

The apparatus in accordance with the present invention is simplified with regard to conventional "taped bag" loading equipment because of the lack of any need for means for disposing of the connecting tape. The bag material itself, in the present process, serves as the means for connecting successive bags to form a chain of bags for feeding.

Claims

1. A packaging process comprising providing a chain of side-sealed packaging bags with the mouths of the bags facing laterally of the chain of bags, feeding said chain of bags to a loading station, inflating the bags at the loading station, loading a product article into each bag, and advancing the loaded bags to a bag closing station.

2. A process according to claim 1, wherein the bags are of plastics material and the side seals of the bags are heat welded.

3. A process according to any one of the preceding claims, wherein the bags remain attached to one another in batches during loading and closing.

4. A process according to claim 3, wherein said bags are advanced in a batch on a conveyor belt which indexes the bag chain from a bag feed station to the loading station, and then advances this batch of bags from the loading station to a separate bag closing station, and then from the bag closing station to a subsequent delivery station.

5. A process according to claim 4, and further including the step of shrinking said bags to shrinktidy the package after bag closing.

6. A process according to claim 5, wherein at the bag closing station the bags are evacuated.

7. A process according to claim 5, wherein at the bag loading station the interior of each bag is flushed with a gas which is inert to the product article loaded in the bag.

8. A process according to any one of the preceding claims, wherein the bags in the chain are partially separated from one another before arrival at the loading station.

9. A process according to claim 8, wherein the bags in the chain are connected to one another at their mouth ends by a line of perforations to define a zone of weakness at which the bags can subsequently be separated, and they are separated from one another along at least a part of the remainder of the side seals of the bags.

10. A process according to claim 9, when the bags in the chain are furthermore connected to one another by a line of perforations at the ends of the side seals adjacent the closed ends of the bags.

11. A process according to any one of claims 1 to 10, wherein said bags in the chain each have two opposed faces of which one face has a length greater than the length of the opposite face, such that said one face defines the margin of said chains at which said bag mouths are disposed.

1 2. A process according to any one of the preceding claims, wherein the chain of bags is double-sided in that it comprises two separate sets of bags of which one set has the bag mouths facing laterally at one margin of the chain, and another set of bags has its mouths facing laterally at the opposite margin of the chain; and wherein along a longitudinal line of the chain, between the said two margins, the bags are connected along at least one seal line defining the bottom end of each bag.

13. A packaging apparatus comprising a bag loading station including a plurality of product loading chutes; means for advancing a chain of side-seaied bags to said product loading chutes while the bags are still attached to one another along at least a part of their side sealed edges; means for holding each of said bags alongside a respective one of said product loading chutes at the loading station; means for moving the various product loading chutes towards and away from one another at the loading station so as to vary the spacing between adjacent ones of said chutes and to facilitate billowing of the bags during bag loading; means for opening the individual bags held adjacent said associated product loading chutes; and means for closing the bags after loading.

14. Apparatus according to claim 13, wherein said bag-closing means comprises a hot weld sealing means for sealing the bag mouth in a flat configuration.

15. Apparatus according to claim 13 or 14, wherein said bag closing means is at a subsequent bag closing station downstream from said product loading chutes, when considered in the direction of movement of the bag chain to the product loading chutes; and wherein said apparatus further includes means for advancing the loaded bags from the product loading chutes to the bag closing means.

1 6. Apparatus according to claim 14 or 15, wherein said bag closing station comprises a chamber defined by a hood which is movable between an open position allowing introduction o;f bags into said chamber and a closed position in which said chamber is isolated from the ambient' atmosphere.

17. Apparatus according to claim 16, wherein said chamber is a vacuum chamber with said bag closing means therewithin.

18. Apparatus according to claiml 6, wherein said chamber is an inert gas flushing chamber with said bag closing means therewithin.

19. Apparatus according to any one of claims 16 to 18, taken together with claim 15, wherein the means for advancing the bags from the product loading chutes to the bag closing station comprise a conveyor belt on which said bags rest and which is engaged by said hood to define therewith said chamber.

20. Apparatus according to claims 14 and 19, wherein said conveyor belt carries strips which form part of said hot weld bag closing means, and including means for indexing said conveyor belt between one position in which a said strip is in register with the various product loading chutes, and a next successive position in which said strip is located within said chamber.

21. Apparatus according to any one of claims 13 to 20 and including a programmer effective to ensure sequencing of the movement of the bag loading chutes and the operation of the bag closing means such that initially the product loading chutes are in a first configuration at relatively widely spaced intervals from one another as the bags are taken up by said holding means, and that secondly the product loading chutes close together to a second configuration in which the various product loading chutes are more closely spaced with respect to one another and the bag opening and bag loading operations can then more easily take place, and that finally the product loading chutes return to their said first configuration before operation of the bag closing means takes place.

22. Apparatus according to any one of claims 1 3 to 21, wherein said means for holding the bags alongside said respective product loading chutes comprise individual gripper jaws mounted on said respective product loading chutes, and means for simultaneously operating each of said gripper jaws to grip a batch of bags simultaneously and to release a batch of bags simultaneously.

23. Apparatus according to any one of claims 13 to 22, wherein said product loading chutes are releasably carried on support means allowing their lateral movement towards and away from one another, and including adjustable means for spacing the individual product loading chutes with respect to one another such that when a larger number of product loading chutes is in use on said guide means the distance travelled by each said product loading chute is less than for a smaller number of product loading chutes.

23. Apparatus according to any one of claims 1 3 to 22, wherein said product loading chutes are releasably carried on support means allowing their lateral movement towards and away from one another, and including adjustable means for spacing the'individual product loading chutes with respect to one another such that when a larger number of product loading chutes is in use on said guide means the distance travelled between said product loading chute is less than for a smaller number of product loading chutes.

24. Apparatus according to claim 23, wherein said adjustable means for spacing the individual product loading chutes from one another comprise a set of replaceable straps, each strap being arranged to interconnect one of said product loading chutes with the next adjacent said product loading chute, and each said strap having lost motion connection means to permit limited travel of said one product loading chute laterally towards and away from said next adjacent product loading chute.

25. Apparatus according to claim 24, wherein said lost motion connection means comprise a slot extending longitudinally of said strap, and wherein each said product loading chute includes means for engaging a respective end of an associated said strap.

26. Apparatus according to claim 25, and including quick-release means for connecting said straps to said product loading chutes.

27. A packaging process substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

28. Packaging apparatus substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

29. A package formed by the process of any one of claims 1 to 12, or by use of the apparatus of any one of claims 13 to 26.

New claims or amendments to claims filed on 26 January 1981 Superseded claims 1 to 5 New or amended claims:

1. A packaging process comprising providing a chain of side-sealed bags having laterally facing mouths; feeding said chain of bags to a loading station; inflating a batch of said bags at the loading station; loading said batch of bags with product; and advancing said batch of bags to a bag closing station.

2. A packaging process comprising providing a chain of side-sealed bags having laterally facing mouths; feeding a batch of bags of said chain to a loading station; separating that batch from the rest of the chain of bags; opening the batch of said bags at the loading station; loading said batch of bags with product; advancing said batch of bags to a bag closing station; and continuing the process with the next batch of bags of said chain.

3. A process according to claim 1 or 2, wherein the bags are of plastics material and the side seals of the bag are heat welded.

4. A process according to claim 3, wherein said bags are advanced in said batch on a conveyor belt which indexes the bag chain from a bag feed station to the loading station, and then advances this batch of bags from the loading station to a separate bag closing station, and then from the bag closing station to a subsequent delivery station.

New claims or amendments to claims filed on 29April1981 Superseded claims 7, 10,23 New or amended claims:

7. A process according to claim 5, wherein at the bag closing station the interior of each bag is flushed with a gas which is inert to the product article loaded in the bag.

10. A process according to claim 9, wherein the bags in the chain are furthermore connected to one another by a line of perforations at the ends of the side seals adjacent the closed ends of the bags.