GB2351035A

GB2351035A - Bags with tongues and method and apparatus for making them

Info

Publication number: GB2351035A
Application number: GB9924366A
Authority: GB
Inventors: David Robert Seaward; Thomas William Bailey; Geoffrey William Vernon
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1999-06-14
Filing date: 1999-10-14
Publication date: 2000-12-20
Also published as: GB9924366D0; GB9913771D0

Abstract

A bag comprises two sidewalls 52, 54, a tongue 68 disposed inwardly of each sidewall and walls 84 connecting the base of the tongue to the top of the sidewalls and is suitable for packaging coffee, tea or detergent. The tongues extend parallel to the sidewalls. The tongues 68 width is preferably smaller than that of the sidewalls 82, 84 and its lower end preferably disposed lower than the top of the sidewalls. The bag can be a DOY bag which comprises a w-shaped gusset (58, figure 4) at the base of the bag. The bag preferably has stiffening seals along all its edges 88 and between the edge of the sidewalls and the top of the sidewalls 90. A zip closure (78, figure 4) may be provided. The method and apparatus for making the bag comprise means for forming a continuous web (figures 7-11) which comprises sidewalls and tongues extending generally parallel to and inwardly therefrom via connecting walls and means for forming seals transversely across the web (figures 12 and 14). The packaging materials for forming the web may be fed downwards to form the web and the web may be fed downwards prior to being filled, sealed and separated and having its tongues trimmed. The sealing means may comprise rotary opposed drums with heating surfaces extending circumferentially (444, figure 14) and longitudinally (446, figure 14) around the drum. The forming means may comprise means for fusing a plurality of webs, preferably three, into a continuous web which can contain a w-shaped base wall.

Description

2351035 Packagin The invention relates to packaging and particularly, but

not exclusively, to packages known as DOY bags.

DOY bags are a known form of packaging and are conventionally made on horizontal form, fill and seal (HFFS) machines. A typical prior art DOY bag is shown in Figure 1.

The DOY bag 10 shown in Figure 1, would typically be fori-ned by running a heat sealable plastics web horizontally over a former set arranged to cause the web to adopt the generally W-shaped cross-section as shown in Figure 2. Vertically oriented seals 14 (Figure 1) are then made between the opposed sides 16,18 of the web at bag width intervals so as to produce a series of interconnected pouches having an open top and sealed vertical sides. Opposed areas of the lowermost portion of the web, as indicated at 20, are sealed together whilst retaining the W-section, so forming a stiffened base on which the bag can stand. The bag is then filled from above and a transverse seal 21 formed at its upper end. The filled and sealed bags so-formed are then separated by cutting through the vertical edge seals 14. This general process is known and is, for example, disclosed in US4361235, the content of which is incorporated herein by reference.

The DOY bag 10 may be provided with a zip closure 22 and/or a valve 24.

The invention provides a DOY bag having opposed sidewalls, each having an upper end and a tongue provided in the region of and inwardly of said upper ends, said tongue being carried on respective connecting walls which extend inwardly from said upper ends of the sidewalls.

The invention also includes a bag made of a flexible material, said bag comprising opposed sidewalls each having an upper end, a lower end and edges, which edges extend between said upper and lower ends, a tongue extending generally parallel to and disposed axially inwardly of said sidewalls and respective connecting walls extending between the region of said upper ends of said sidewalls and a lower end region of an adjacent one of said wall elements, 2 said tongue comprising opposed wall elements arranged to define a passage to a bag space defined between said sidewalls.

The invention also includes a method of making a bag, said method comprising the steps of. forming packaging material into a continuous web having opposed sidewalls each having a first end and a second end, opposed wall elements disposed axially inwardly of said sidewalls and extending generally parallel thereto, and respective connecting walls extending between said sidewalls in the region of said first ends and a nearest one of said wall elements; and forming seals transverse to a lengthwise direction of said web so as to define successive bags each having a bag space between said sidewalls and a passage to said bag space provided in a tongue defined by said wall elements.

The tongue may have a width which is less than the width of the bag.

The invention also includes a bag making apparatus comprising: means for forming packaging material into a continuous web defining opposed body sidewalls each having a first end and a second end, opposed tongue sidewalls disposed axially inwardly of said body sidewalls, and respective connecting walls connecting said tongue sidewalls to a nearest one of said body sidewalls; and sealing means for forming seals transverse to a lengthwise direction of said web so as to define successive bags each having a bag space between said body sidewalls and a tongue defined by said tongue sidewalls which tongue defines a passage which opens into said bag space.

In order that the invention may be well understood, some embodiments thereof, which are given by way of example only, will now be described with reference to the drawings, in which:

Figure 1 is a perspective view of a prior art DOY bag;

Figure 2 is a perspective view of a W-section web from which the prior art DOY bag would typically be produced; Figure 3 is front elevation view of a bag according to the invention; Figure 4 is a cross-section view on line IV - IV in Figure 3; Figure 5 is a schematic perspective view of the bag shown in Figures 3 and 4, showing a modification to the bag; 3 1 - rw-JL Figure 6 is an illustration of a machine for manufacturing a bag according to the invention; Figures 7 to I I illustrate steps of a forming process performed by the machine shown in Figure 6; Figure 12 is a schematic perspective view of another machine for manufacturing a bag according to the invention; Figure 13 is a scrap section showing the formation of a W-section in a web by means of the machine shown in Figure 12; and Figure 14 is a perspective view showing the sealing rollers of the machine shown in Figure 12.

Referring to Figures 3 to 5, a bag 50 comprises two opposed sidewalls 52, 54. The sidewalls are interconnected at the base 56 of the bag by a wall, or gusset, 58 and are sealed together along their upright edges by two edge seals 60, which extend from the base 56 to the upper ends 62 of the sidewalls so as to define a bag space 64. The wall 58 may be integral with the sidewalls 52, 54, or a separate element joined to the sidewalls, and is folded such that it projects inwardly into the bag space 64.

Diagonal seals 66 are provided across the comers of the bag base between the sidewalls 52,54 and the respective opposed portions of the wall 58.

It will be understood that typically, the material of which the bag is made permits heat sealing of the inner surfaces of the sidewalls 52,54 to the opposed inner surfaces of the wall 58, but does not allow the external faces of the wall 58 to bond to one another. Packaging materials having this property are well known to those skilled in the art and for that reason will not be described in more detail herein. As an alternative, if the packaging material is not in itself heat sealable, an adhesive can be applied to the material in a suitable pattern to allow the production of diagonal seals as shown in Figure 3.

The diagonal seals 66 serve to ensure that the W-section of the base of the bag, as shown in Figure 4, is maintained, until the bag is filled, and provide the base 56 with a degree of stifffiess such that, when filled, the bag is able to stand unsupported.

4 The bag described thus far is a conventional DOY bag and will be familiar to those skilled in the art.

The bag 50 has a tongue 68 (Figure 5) provided at its upper end. The tongue 68 is defined by opposed sidewalls, 70, 72 which are joined together at their edges by upwardly extending side seals 74. At their upper ends, the tongue sidewalls 70, 72 are joined together by a transverse seal 76 which extends between the side seals 74. A zipper strip 78 may be provided adjacent the transverse seal 76 so that the bag can be resealed once it has been opened.

The tongue sidewall 70 is connected with the upper end 62 of the sidewall 52 by a connecting wall, or gusset, 82 and the tongue sidewall 72 is likewise connected with the upper end 62 of the sidewall 54 by a connecting wall, or gusset, 84. The connecting walls 82, 84 extend downwardly from the upper ends 62 of the sidewalls 52, 54 into the bag space 64 and connect with the lowermost, transverse, edges 86 of the respective tongue sidewalls 70, 72.

It will be appreciated that the bag 50 in effect has inwardly extending gussets at its upper and lower ends, the upper end gussets supporting the tongue 68. As compared with a conventional DOY bag, this allows a greater volume to be obtained for the same height bag. It will also be appreciated that the provision of the tongue permits the incorporation of features which make the bag more attractive to users than it would be if the connecting walls 82, 84 were joined to each other at their lower ends so as to produce a seal disposed below the level of the wall upper ends 62 of the sidewalls 52,54. For example, as previously described, a transverse zipper can readily be accommodated making the bag resealable. Furthermore, the tongue allows easy access for opening the bag and does not require that the bag be opened in the vicinity of the upper level of its contents which will typically be below the level of the tongue.

Additionally, the tongue may serve as a convenient ftmel which facilitates emptying of the bag by a user and through which product can be poured into the bag space 64 during filling of the bag.

The tongue could be provided with a tab 80 as shown in Figure 5. The tab 80 comprises opposed wings defined by respective upward extensions of the tongue sidewalls 70,72. The wings are preferably not sealed to each other so they may be used as an aid to peel the walls 70,72 of the tongue apart when opening the bag. An aperture may be provided in the tab so that the bag may be hung for display purposes. If the tab wings are not to be used as an aid to opening the bag, they may be sealed together to provide reinforcement, for hanging purposes.

If desired, a transverse seal 88 (Figure 5) may be provided between the upper end 62 of the sidewall 52 and the connecting wall 82 in order to strengthen the bag structure. A similar seal 88 may also be provided between the upper end 62 of the sidewall 54 and the connecting wall 84.

If desired, the tongue 68 can be arranged such that it can be folded down beneath the sidewall upper ends 62. This would make the bag more compact for transportation purposes.

It will be understood that in place of the diagonal seals 66, the base of the bag may be stiffened by a continuous transverse seal 20 having a zonal configuration similar to that shown in Figure 1. As with the diagonal seals 66, such zonal seals would be made by forming seals between the inner surfaces of the sidewalls 52, 54 and opposed portions of the inner surfaces of the wall 58, without sealing between the external faces of the wall 58.

Diagonal seals 90 (Figure 5) similar to the diagonal seal 66 may also be provided at the upper end of the bag. Alternatively a zonal seal 20, rotated through 180' in the plane of the drawing sheet, may be provided instead of the diagonal seals 90.

The bag 50 may be produced on a conventional in-line horizontal DOY bag making machine or a bag making machine as disclosed in US4361235. In either case, it would be necessary to provide forming equipment to produce inward tucks, or folds, in the upper ends of the W-section web shown in Figure 2 in order to arrive at a section similar to that shown in Figure 4. This could be achieved by providing a forming station the same as, or similar to, the forming station 220 described below with reference to Figures 6 to 11. It would also be necessary to provide means for cutting notches out of the web so as to make the tongue narrower than the sidewalls 52, 54.

6 The machinery disclosed in US4361235 and other conventional DOY bag making machines have an intermittent web movement, the web being halted during the sealing processes. Two embodiments of bag making apparatus which permit continuous motion of the web and the associated speed advantages will now be described.

A horizontal DOY bag making machine 200 for manufacturing the bag will now be described with reference to Figures 6 to 11. The machine 200 includes a reel stand (not shown) which supports a reel 202 of packaging material. A second reel 204 of packaging material supported on another reel stand (not shown) is positioned adjacent the first reel 202. A splicing unit, indicated schematically at 205, is positioned adjacent the reels 202, 204. The splicing unit, which can be of any suitable conventional form, is arranged to splice the tail end of the packaging material from an exhausting reel 202, 204 to the leading end of a fresh reel 202, 204 to permit continuous operation of the machine 200 during reel changeover.

A web 206 of the packaging material is drawn from the in-use reel 202, 204 and is directed to a flow former 208 via a guide arrangement which is not shown in detail and includes guide rollers 210, 212, and 214 by which the web is fed underneath the flow former and then turned back to run into the flow former.

The flow former 208, which is a conventional device well known to those skilled in the art, causes the web 206 to fold about its longitudinal axis bringing the edges 206A, 206B of the web into an opposed spaced apart relationship such that on exiting the flow former, the web has a generally V shaped cross-section. A plate, or wheel, 216 is positioned downstream of the flow former and beneath the web where it exits the flow former. The plate 216 is arranged to exert an upward force against the apex of the V-section web so that as the web moves over it, the web is caused to fold inwardly so as to adopt a generally W-section configuration similar to that shown schematically in Figure 7.

The W-section web then passes through nip rollers 218 to a forming station indicated at 220. The various components of the forming station 220 are 7 arranged to work on the outer arms 222 (Figure 7) of the W-section web to produce the bag cross-section shown in Figure 4 and in particular to produce folds in the arms 222 which define the sidewalls 70, 72 of the tongue 68.

The forming station 220 has parts for operating on both arms 222 and these parts may be staggered or arranged to act simultaneously on the two arms.

In the description which follows, reference will only be made to the processes affecting one arm 222, although as indicated above, similar processes will be carried out on both arms.

On entering the forming station 220, the arm 222 is moved against a plough folder (indicated schematically at 224 in Figure 7) which causes the free end 226 of the an-n 220 to fold outwardly to the position shown in Figure 8 and produces a fold 229. Plough folders are devices well known to those skilled in the art and accordingly will not be described in detail herein.

Downstream of the plough folder 224, the outwardly projecting portion 226 of the arm 222 passes between two thin plates 228, 230. The height of the plate 230 increases in the downstream direction in the plane perpendicular to that of the drawing sheet. The arrangement of the plates 228, 230 is such that there is a progressively increasing overlap between them. This increasing overlap causes the projecting portion 226 to be progressively folded through an angle approaching 90' to bring the projecting portion to the position shown in Figure 9.

A second plough folder 232 is positioned downstream of the plates 228, 230, The second plough folder 232 produces a fold 234 in the arm which creates a portion 236 immediately below the portion 226, which is directed inwardly of the W-section as shown in Figure 10.

Downstream of the second plough folder 232, the forming station 218 has two plates 238, 240 which are similar to the plates 228, 230 of Figure 8. The plates 238, 240 are arranged to act on the inwardly projecting portion 236 of the arm, progressively turning it through an angle approaching 90' to bring the arm portions 226, 236 to the position shown in Figure 11.

Thus, as indicated in Figure 11, the forming station 220 produces two folds 229, 234 in the arm 220 which define three distinct arm portions 226, 236 8 and 242; the portion 242 being the portion extending from the portion 236 to the end of the arm where it joins the inner portion of the W-section. It will be appreciated that the portions 226, 236 and 242 respectively define the sidewall 52, connecting wall 82 and tongue sidewall 70 of the bag 50.

It will be understood that the plough folders 224 and 232 together with the plates 228, 230, 238 and 240 are all static and the changes in the configuration of the arm 222 are produced by flow forming processes as the web is drawn past those elements. In the drawing, the forming station 220 has not been shown to scale and in practice, in order to achieve the described change in the configuration of the arm 222 by flow forming processes, the forming station should preferably have a length in the region of 1.5 to 2m.

A sealing device 250 is positioned downstream of the forming station 220. The sealing device comprises endless belts 252, 254 which each carry a plurality of scaling stations 256; for example, in the embodiment there are sixteen sealing stations 256. The web 206 exiting the forming station 220, passes between the sealing belts 252, 254 which have a linear speed corresponding to the web, and the sealing stations produce respective combinations of seals 60, 66 and 74 (Figure 3) such that the web exits the sealing device in the form of a string of unfilled, open-topped bags 50.

A cutting station 258 is located downstream of the scaling device and is arranged to cut through the seals 60 in the lengthwise direction thereof and to trim the tongues. Accordingly, on exiting the cutting station 258, the bags 50 are separated from one another and have tongues which have been trimmed to the seals 74 such that the tongues 68 have a width which is somewhat less than the width of the bag as defined by the side walls 52, 54.

The individual bags 50 exiting the cutting station are collected on respective seats 262 of a carousel 264. The seats 262 are connected with a suction source which generates a suction force that first attracts the bags to the seats and then retains the bags in a seated position. The carousel 264, which in the embodiment has 48 such seats, transports the bags past a vacuum belt 266 which draws against the sidewall of the bags disposed remote from the seats 262 so as to open the bag for filling.

9 A filling device 270 is positioned above the carousel so as to be able to deposit product into the open bags. The device shown in Figure 6 is of a conventional design suitable for delivering instant coffee into the bags and its features will be familiar to those skilled in the art of packaging coffee. It will be understood that the bag 50 can be filled with any material or product which is capable of being dropped into the opening of the bag and in principle any suitable device for delivering such material or product, for example, a liquid rotary filler or an auger filler with knife edge plates, could be utilised in place of the filling device 270. Accordingly, no further description of the filling device

270 will be provided herein.

The seats 262 are each supported by a downwardly extending shaft 272.

The shafts 272 pass through respective through-bores provided in the carousel and each has a cam follower 274 which engages a circumferentially extending cam track 276 disposed below the carousel; the carousel is shown in Figure 6 with its rim cutaway to show the through-bores and the cam track 276.

The cam track 276 is configured such that when filled, the bags drop away from the filling device 270 before passing into a second sealing device 280. It will be appreciated that the cam track is also configured to raise the bags towards the filling device as the opened bags move from the downstream end of the vacuum belt 266 towards a the region occupied by a trough 282 of the filling device.

The second sealing device 280 comprises opposed endless scaling belts which are arranged to form the top seal 76 of the bag. On exiting the sealing device 280, a system of guide belts guides the finished bags around a plate 282 onto an outlet conveyor 284.

It will be appreciated that the DOY bag maker 200 could readily be adapted to provide the bag 50 with a zipper strip 78, or a valve such as the valve 24 shown in Figure 1. Arrangements for adding zipper strips and valves to bags by essentially horizontal bag making processes are known to those skilled in the art and will not therefore be described in any detail herein. In the case of the bag maker 200, the zipper strip 78 would preferably be fed between the opposed sides of the web at a position between the forming station 220 and the scaling device 250 from a zip feeding device indicated at 290. In this case, the sealing stations 256 carried by one of the belts 252, 254 would preferably be arranged to at least partially seal the zipper strip to one of the opposed sides of the web.

Sealing of the zipper strip to the bag would then preferably be carried out at the second sealing device 280 at the same time as the top seal 76 is formed.

A bag making apparatus 400 for manufacturing a bag similar to the bag will now be described with reference to Figures 12 to 14.

The bag making apparatus 400 comprises a roller 402 for mounting a reel of a heat sealable packaging material. A web 404 of the packaging material passes from the roller 402 to a triangular flow forming plate 406 via an idler roller 408. The idler roller 408 guides the web into the forming plate 406 by turning it through 90' such that as it passes over the forming plate, the web is moving vertically downwards towards a pair of nip rollers 410.

The flow forming plate 406 defines, or may have fixed to it, a W-section rib 412 (Figure 13) which extends over a relatively short distance in the lengthwise direction of the forming plate. A generally rectangular gusset forming plate 414 is positioned adjacent to the rib 412 such that a lengthwise extending edge of the plate extends parallel to and in the plane of the axis of the rib. The arrangement is such that the forming plate 406 causes the web 404 to fold along its longitudinal axis bringing the edges 404A,404B into an opposed spaced apart relationship and the rib 412 and gusset forming plate 414 act on the web in the region of the fold to form an inward tuck (Figure 13) thereby causing the web to adopt a generally W-section similar to that shown in Figure 2.

A forming set 418 (represented schematically in Figure 12) is located downstream of the nip rollers 410. The forming set 418 has the same function and performs substantially the same operations as the forming station 220 shown in Figure 6 and described with reference to Figures 7 to 11.

It will be appreciated that the forming plate 406 and the forming station 418 have not been shown to scale in Figure 12, which is intended simply to illustrate a process for making the bag rather than provide a representation of an actual machine layout.

Two heated sealing rollers 420 (described in more detail below) are positioned downstream of the forming station 418. These contra-rotating rollers are disposed in opposed spaced apart relationship and in addition to heat sealing the web 404 to produce successive bags, they also serve to draw the web over the idler roller 408 in a continuous manner. Of course, other drive rollers can be provided to perform this function in addition to, or instead of the sealing rollers 418. For example, the nip rollers could be driven for this purpose.

The bag making apparatus 400 additionally comprises a device 422 for feeding predetermined amounts of product into the space between the arms 424 (Figure 13) of the web 404. The device 422 feeds predetermined amounts of product, for example ground coffee, into the space between the arms 424 in a direction transverse to the downward movement of the web.

The device 422 includes a filling tube 426, which extends generally parallel to the direction of travel of the web and is arranged to receive product from a primary source 428. At its downstream end the filling tube 426 feeds into a feed tube 430 which is inclined with respect to the filling tube and has a tapering nozzle 432 which is directed towards the space between the web arms 424. The feed tube 430 defines a chamber positioned immediately upstream of the nozzle 432 which chamber receives product from the filling tube 426. An auger (not shown) may be provided in the filling tube to pump the product into the chamber where the product, for example ground coffee, does not flow readily. The feeding device 422 has a reciprocating plunger 436 positioned in the feed tube 430 and arranged to be driven through the chamber so as to push a required amount of product into the space between the arms 424.

As shown in Figure 14, the sealing rollers 420 carry a number of raised ribs which apply heat to the web so as to seal opposed portions of the web to one another in a predetermined pattern. Adjacent each end of the sealing rollers, there are respective circumferentially extending ribs 440,442. A further circumferentially extending rib 444 is provided intermediate the ribs 440, 442 and the three circumferential ribs are interconnected by a plurality of transverse ribs 446, which extend parallel to the axis of rotation of the sealing roller. Each roller has four such ribs so that they can make four transverse seals per 12 revolution. The trailing edge of each transverse rib 446 may be relieved to provide a shock absorbing facility when product is injected by the filling device 422: this feature will be described in more detail hereinbelow. On each side of each of the transverse ribs 446, there are diagonal ribs 448 which extend between the sides of the respective ribs 446 and the circumferentially extending rib 440.

A severing device, in the form of two reciprocating blades 450 is provided downstream of the sealing rollers 420. The blades 450 have their cutting edges disposed parallel to the transverse ribs 446 and are arranged to cut through seals formed by those ribs in order to separate the completed bags from one another. It will be appreciated that instead of reciprocating blades, rollers carrying cutting blades may be used or the sealing rollers may carry cutting means. Alternatively, non-contact cutting means such as ultrasound, laser or heat cutters might be used. As a further alternative, the blades 450 may be arranged to form a line of perforations along the seals produced by the transverse ribs 446 so that the machine can produce strings of bags which can be readily separated from one another by the consumer.

In use, the web 404 is drawn continuously over the idler roller 408 by the sealing rollers 420 and passes downwardly over the forming plate 406 and between the rib 412 and the gusset forming plate 414. At this point, the web has been caused to adopt a generally W-section. The W-section web passes between the nip rollers 410 and past the forming set 418. The forming set 418 acts on the moving web as indicated in Figures 7 to 11 so that on reaching the downstream end of the forming set, the web has a cross-section similar to that shown in Figure 4, but without the top seal and with at least the walls 70,72 (which define the tongue of the completed bag) spaced far enough apart to permit the insertion of product. A spreading device (not shown) for separating the walls 70,72 to permit access by the nozzle 432 may be incorporated in, or provided downstream of, the forming set 418. Next, one or more doses of product are injected between the arms 424 such that each bag formed will contain a predetermined amount of product. As the web passes between the sealing rollers 420, the walls 70,72 are pressed together and at regular intervals, which are 13 determined by the speed of rotation of the sealing rollers, transverse seals 452 are formed by the ribs 446. The circumferentially extending ribs 440,442, 444 form respective seals 454,456,458 extending continuously in the lengthwise direction of the web and the diagonal ribs form respective diagonal seals 460 extending between the transverse seals 452 and the circumferential seal 454. As the web passes from the sealing rollers between the cutting blades 450, transverse cuts are made along the seals 452 to separate the newly formed bags from one another.

As mentioned above, each transverse rib 446 may have its trailing edge relieved. The effect of this is that subsequent to the formation of a seal 452 by a pair of opposed ribs 446, the relieved portions of the ribs maintain those portions of the two sides of the web, which are adjacent the seal, in relatively close proximity for a short period of time sufficient to allow injection of the required amount of product. This provides a degree of shock absorption by preventing the product from impinging directly on the newly formed seals 452.

It will be appreciated that the newly formed bags 462 exiting the sealing rollers 420 are similar to the bag 50 shown in Figures 3 to 5. Onedifference between the bags is that the tongue 464 of the bag 462 is the same width as the body portion of the bag. However, it will be understood that if it is desired to make the tongue 464 narrower than the bag, the cutting blades. or other cutting means used to separate the bags, may be arranged to cut suitable notches in the tongues 464; alternatively, the notches could be cut upstream of the sealing rollers, or during the sealing process, by suitable cutting means. A further difference is that the bag 462 has seals 454 extending between the edge seals at what in use will be the lowermost end of the bag. These seals are similar to the seals 20 shown in Figure 1 and serve to further stiffen the base of the bag.

In the previously described bag making apparatus, the bag 50 had been made from a single continuous web of packaging material. It will be understood that the bag could be made from a plurality of webs fed into an interleaving relationship and sealed together. For example, the bag could be made from three webs: two providing the material from which the sidewalls and tongue are formed and one feeding a web from which the gusset is formed, between the 14 other two webs. An example of a machine and process which could be adapted to make the bag 50 from a plurality of webs is disclosed in US5542902, the disclosure of which is incorporated herein by reference.

Claims

Claim

I. A DOY bag having opposed sidewalls, each having an upper end, and a tongue provided in the region of and inwardly of said upper ends, said tongue being carried on respective connecting walls which extend inwardly from said upper ends of the sidewalls.
2. A bag made of a flexible material, said bag comprising opposed sidewalls each having an upper end, a lower end and edges, which edges extend between said upper and lower ends, a tongue extending generally parallel to and disposed axially inwardly of said sidewalls and respective connecting walls extending between the region of said upper ends of said sidewalls and a lower end region of an adjacent one of said wall elements, said tongue comprising opposed wall elements arranged to define a passage to a bag space defined between said sidewalls.
3. A bag as claimed in claim 2, wherein said lower end regions of said tongue wall elements are disposed lower than said sidewall upper ends and said connecting walls extend downwardly from said upper ends to said lower end regions.
4. A bag as claimed in claim 2 or 3, having at least one seal between a said sidewall and the connecting wall extending therefrom, whereby the bag is stiffened in a region adjacent said seal.
5. A bag as claimed in claim 4, having at least one said stiffening seal extending between said opposite sidewall edges along a said sidewall upper end.
6. A bag as claimed in claim 4 or 5, having at least one said stiffening seal which defines a line extending between a said sidewall edge and the upper end of the respective sidewall.

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7. A bag as claimed in any one of claims 2 to 6, wherein said sidewalls are scaled together in the region of said edges by respective edge seals and further comprising a gusset extending between said sidewalls in the region of said lower ends, the arrangement being such that said sidewalls and said gusset define said bag space.
8. A bag as claimed in claim 7, wherein said edge seals extend continuously from said lower ends to said upper ends of the sidewalls.
9. A bag as claimed in any one of the preceding claims, wherein said sidewalls have a width defined by said edges and said tongue has a width less than said width of the sidewalls.
10. A method of making a bag, said method comprising the steps of. forming packaging material into a continuous web having opposed sidewalls each having a first end and a second end, opposed wall elements disposed axially inwardly of said sidewalls and extending generally parallel thereto, and respective connecting walls extending between said sidewalls in the region of said first ends and a nearest one of said wall elements; and forming seals transverse to a lengthwise direction of said web so as to define successive bags each having a bag space between said sidewalls and a passage to said bag space provided in a tongue defined by said wall elements.
11. A method as claimed in claim 10, comprising transporting said bags to a filling station whereat a product to be packaged is fed into the respective bag spaces via said passages.
12. A method as claimed in claim I I further comprising forming a transverse seal between respective ends of said wall elements disposed remote from said connecting walls such that said product is sealed within the respective bags.

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13. A method as claimed in claim 10, 11 or 12, further comprising severing said web such that said bags are separated one from the other.
14. A method as claimed in any one of claims 10 to 13, further comprising cutting said wall elements such that said wall elements have a width less than that of said sidewalls.
15. A method as claimed in any one of claims 10 to 14, further comprising forming at least one seal between said sidewalls and the respective connecting walls extending therefrom, whereby a region of said web containing said seal is stiffened.
16. A method as claimed in claim 15, wherein the or at least one said stiffening seal extends continuously along said first ends of said sidewalls.
17. A method as claimed in claim 15 or 16, wherein the or at least one said stiffening seal defines a line extending between a said transverse seal and the first end of the respective sidewall.
18. A method as claimed in any one of claims 12 to 17, wherein said transverse seals define a line extending continuously between said second ends of the sidewalls and a respective end of said wall elements disposed remote from said connecting walls.
19. A method as claimed in any one of claims 10 to 18, wherein said web forming step includes forming a gusset extending between said sidewalls at or adjacent said second ends thereof such that said bag space is defined by said sidewalls and said gusset.
20. A method as claimed in any one of claims 10 to 19, wherein said web forming step includes feeding a plurality of webs of packaging 18 material into a predetermined relationship and joining said webs to define said continuous web.
21. Bag making apparatus comprising: means for forming packaging material into a continuous web defining opposed body sidewalls each having a first end and a second end, opposed tongue sidewalls disposed axially inwardly of said body sidewalls, and respective connecting walls connecting said tongue sidewalls to a nearest one of said body sidewalls; and sealing means for forming seals transverse to a lengthwise direction of said web so as to define successive bags each having a bag space between said body sidewalls and a tongue defined by said tongue sidewalls which tongue defines a passage which opens into said bag space.
22. Apparatus as claimed in claim 21, wherein said web is fed downwardly towards said sealing means with said tongue sidewalls in spaced apart relationship so as to define an opening extending in a lengthwise direction of said web and comprising a feed device arranged to direct product through said opening in a direction transverse to said lengthwise direction such that said product is received between said body sidewalls at a position upstream of and adjacent said sealing means.
23. Apparatus as claimed in claim 21 or 22, wherein said packaging material is fed downwardly whilst being formed into said web by said forming means.
24. Apparatus as claimed in claim 21, 22 or 23, wherein said sealing means comprises opposed rotary devices each having heat applying surfaces extending parallel to an axis of rotation of the device, said heat applying surfaces being cooperable for forming said transverse seals.
25. Apparatus as claimed in claim 24, wherein each said device comprises a drum which has at least one circumferentially extending heat 19 applying surface for forming a continuous seal extending in a lengthwise direction of said web.
26. Apparatus as claimed in claim 2 1, wherein said forming means comprises means for feeding a plurality of packaging webs into a predetermined relationship and joining said webs to define said continuous web.
27. Apparatus as claimed in any one of claims 21 to 26, wherein said forming means is arranged to form said packaging material into a continuous web with a base wall extending between said body sidewalls at or adjacent said second ends.