GB2065599A

GB2065599A - Liquid packaging system

Info

Publication number: GB2065599A
Application number: GB7943872A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-12-20
Filing date: 1979-12-20
Publication date: 1981-07-01
Also published as: GB2065599B

Abstract

A liquid container from which the liquid 6 can be dispensed through a dispensing adaptor or tap 9, 10, comprises an inner fluid- tight bag 2 formed with an outer layer or bag 3 which provides a liquid-tight compartment on the outside of the bag 2; the outer layer or bag 3 having an opening 7 for receiving the dispensing adaptor 9, 10, and the inner member 9 of the dispensing adaptor being inserted through the opening 7 by the user of the container prior to fitting the outer part 10 of the adaptor. <IMAGE>

Description

SPECIFICATION Liquid packaging system Background of the Invention The present invention relates to dispensing liquids from flexible, liquid-tight bags. Machines known as form, fill and seal machines are well known, and are used to make bags from flat material, fill the bags and seal them.

It has been known that this was possible with liquids, and some machines are so used, but convenient dispensing of the liquid is a problem, particularly in circumstances where the whole contents of the bag are not to be dispensed at the same time. In one arrangement, a bag is pre-made, open at the top, with a circular opening in one of the side walls; a dispensing adaptor is fitted to the opening by hand by holding one plastic clamping ring within the bag and another plastic clamping ring on the outside. It would be very difficult to form, fill and seal the bag completely automatically. In another arrangement, a dispensing adaptor in the form of a tap is welded to the bag, which is a cumbersome and expensive procedure and again is difficult to automate.

From another aspect, difficulties are caused with liquids if there are any creases or puckers in the material of the bag prior to sealing as such creases or puckers can cause the bag to leak.

The Invention According to one aspect of the invention, the invention provides a container, a method and a machine as set forth in claims 1, 10 and 14 respectively. According to another aspect, the invention provides a method, a machine and a bag as set forth in claims 18, 20 and 22 respectively. The remaining claims set forth preferred features of the invention.

The first aspect of the invention enables liquids to be supplied in cheap containers and to be dispensed without difficulty. The bags can be formed, filled, sealed and despatched automatically from a suitable machine. When the dispensing adaptor is applied, it does not matter if liquid passes into the space between the wall of the bag and the outer layer as the outer layer is sealed to the bag, though in practice the bag will be pressed against the outer layer by the pressure of liquid and it is not expected that much liquid will pass into the space. For transportation and storage, the bag itself provides the liquid tightness.

The outer layer is preferably provided by having a substantially complete double wall.

Double-wall bags have been made in the past, though in order to increase strength rather than for the purpose of the present invention, and the machinery is easily designed. In the container of the invention, the outer wall contributes to strength, although there may be a small zone where there is not a double wall.

Alternatively however, the outer layer could be just on one side of the bag or could be merely around the portion of the bag that is to be punctured for dispensing the liquid.

In general, the opening will be a preformed hole, though in theory it would be possible to merely have a delineated opening with a piece which can be pushed out by hand or even cut out, and further possibility would be to have no opening or delineation whatsoever, allowing the user to cut out a suitable hole.

The dispensing adaptor will normally be a tap for controlling the dispensing of the liquid.

It would be possible to sell the container with part of the adaptor already between the outer layer and the bag, but the preferred arrangement is to provide the adaptor with the container and to oblige the user to slip the respective part of the adaptor into position.

This can be arranged to be done in such a way that the user would have no difficulty.

The seal that the adaptor makes with the outer layer must be effective, and at the same time there must be an adequate method of piercing the bag along the centre line of the adaptor, so allowing liquid to pass out of the bag. The preferred arrangement is to provide the dispensing adaptor with complementary inner and outer members which are arranged to bear against the inner and outer surfaces of the outer layer, around the opening, and thereby form an annular seal. A screw fitting is preferred between the inner and outer members, though a snap fitting or a force fitting would be possible.An O-ring gives a good seal, but it is preferred to provide a shoulder with an annular recess (facing axially) of curved cross-section for co-operating with or receiving the O-ring: this preventing the O-ring from being pushed radially and allowing leakage, and it is preferred to have the O-ring on the opposite side of the outer layer to the annular recess.

The second aspect of the invention enables puckers to be avoided with much more certainty. The spreader members initially open out the tube, and at the same time, if there is more material on one side than on the other, the tube will slide circumferentially over the spreader members so that both sides are approximately equal in length. The gripper members can then pull the tube out to give a good flat shape and with both sides tensioned approximately to the same extent so that in most cases, puckers can be avoided.

Description of Preferred Embodiment The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a liquid container in accordance with the invention; Figure 2 is a vertical section along the plane ll-ll in Fig. 1 of the container, an outer carton being shown, the wall thicknesses being exaggerated throughout; Figure 2 is a vertical section of part of the container on a larger scale, after the dispensing adaptor has been fitted; Figure 4 is a schematic front elevation of a form, fill and seal machine, modified in accordance with the invention; Figure 5 is a schematic side view (on a smaller scale) of the machine of Fig. 4; and Figure 6 is a section, on a larger scale, along the plane VI-VI in Fig. 5.

The container shown in Figs. 1 and 2 is in the form of a double-walled bag 1 comprising an inner bag 2 and an outer bag or layer 3.

Both layers are welded together longitudinally at the back of the bag 1 (as seen in Fig. 1), the seam 4 being indicated by a dot dash line. Both layers are welded together at the top and the bottom of the bag at double weld seams 5. The bags are made of a flexible material, suitable materials being low density polyethylene, high density polyethylene, nylon, and paper with a low melting point plastics material coating. In theory, the welds could be replaced by adhesive bonds.

The inner bag 2 is liquid-tight and contains a suitable liquid 6 such as milk or wine. The outer bag 3 has a circular opening 7 towards its bottom.

As shown in Fig. 2, the bag 1 is placed inside a relatively rigid, non liquid-tight, stiff cardboard carton 8 which can have carrying handles and a suitable dispensing orifice, in a conventional manner. In addition, the carton 8 contains inner and outer complementary members 9, 10 for forming a dispensing adaptor.

The dispensing adaptor 9, 10 is shown more clearly in Fig. 3. The inner member 9 is in the form of an externally screw-threaded bush having an annular end flange or shoulder which provides an annular recess of semicircular cross-section for co-operating with an O-ring 11. To assist the user, the inner member 9 is preferably not a solid of revolution, in this case being provided with projecting "wings" 1 2 to provide a good grip. The outer member 10 is in the form of a tap with a handle 1 3 and an internally screw-threaded sleeve 1 4 for screwing over the inner member 9. The outer member 10 also carries a spigot 1 5 with a piercer point 1 6 at its end.

To dispense liquid, the user slips the shoulder of the inner member 9 in through the opening 7 (temporarily distorting and stretching the sides of the opening) so that the flange lodges behind the outer layer or bag 3 with the screw-threading projecting out through the opening 7. The O-ring 11 is placed in position and the outer member 10 is then screwed into position. The O-ring 11 provides a good seal, partly because the cooperation of the O-ring 11 with the annular recess increases the area of the outer layer or bag 3 with the O-ring 11.

When the dispensing adaptor 9, 10 is in its proper position, it can be pressed hard against the inner bag 2 so that the piercing point 1 6 penetrates the inner bag 2 and allows the liquid 6 to be dispensed.

Figs. 4 and 5 show an automatic machine 4 making the container of Fig. 1. The machine of Figs. 4 and 5 is basically a known form, fill and seal machine which has been modified in order to incorporate the features of the invention. One such machine could be the G.D.S.T. machine manufactured by M.T.E. Limited.

The main machine has in essence a forming tube 21, a forming shoulder 22 for guiding a flexible web 23 down over the forming tube 21 so that its edges meet and overlap along the front of the forming tube 21 (the righthand side in Fig. 5), a welding bar 24 for forming the vertical seam 4, spreaders 25 for spreading the welded tube, sealer bars 26 for welding and a knife 27 for cutting off in association with the platen 26; the platen 26 and welding bar 27 are also reciprocated vertically so as to feed the web through the machine. There is a filling tube 28 down the centre of the forming tube 21, and in this case, as liquid is being filled, the filling tube 28 is retracted during filling, moving upwards so as to remain always slightly below the surface of the liquid, except at the very beginning of filling.

In accordance with the invention, there is an outer, flexible web 29 over the filling tube 21. The outer web 29 passes a photo-register 30 which senses e.g. pre-printed marks on the outer web 29 and causes the openings 7 to be correctly positioned, and then passes between a punch 31 and die 32 for punching the openings 7. The webs 23, 29 are then placed face-to-face.

The spreaders 25 are not rigid spreaders but are pivoted at 33 and are sprung outwards by a helical tension spring 34. The spreaders 25 thus can move through a substantial range with approximately the same outwards biasing force. The spreaders 25 have smooth, rounded outer surfaces so that the material of the bag can slide circumferentially over them. The spreaders 25 form the tube into a pucker-free shape of elongate (horizontal) cross-section. Below the spreaders 25 there are lateral grippers 35 carried by small pneumatic piston-cylinder units 36 which grip the outside of the tube and pull the tube into a flat shape.

There are four pairs of sealer bars 26, to provide the double seams 5 at the end of each bag (see Fig. 1). The fact that the material has already been folded into a perfectly flat form and the double cross-seams 5 give a reliable leak-proof seal.

To complete the procedure, a carton 8 is indexed under the machine and a forming unit, known as a "forming box", drops the bag 1 into the carton 8 so that the opening 7 is by a corresponding opening in the carton 8.

Such forming boxes are already known, though British Patent Application No.

7901962 can be referred to for description of an improved forming box. The adaptor members 9, 10 are then placed inside the carton 8 (this can also be done automatically if desired) and the carton 8 is closed (which can also be done automatically if desired).

To give one example, two webs 23, 29 of the same thickness plastics material (for instance 0.1 to 0.15 mm) which are 75-90 cms wide can be used to make bags 1 which are about 37-45 cms wide and for instance 60 cms long. The rate can be 10-15 bags per minute for large bags and up to 60 bags per minute for small bags.

Claims

1. A liquid container comprising a flexible, liquid-tight bag containing the liquid, and an outer layer on at least a zone of the bag, the outer layer either having an opening therein for dispensing the liquid, or having an opening delineated therein for dispensing the liquid, and the outer layer otherwise providing a liquid-tight compartment, whereby liquid can be dispensed by fitting a dispensing adaptor to the opening and piercing the bag so that the liquid flows from the bag and out of the dispensing adaptor without leaking from the compartment formed by the outer layer.

2. The container of Claim 1, and being within a substantially rigid, non liquid-tight carton.

3. The container of Claim 1 or 2, wherein the outer layer covers all the bag, forming a substantially complete double wall.

4. The container of Claim 3, wherein the bag is sealed at the top and bottom and the outer layer is sealed to bag at the top and bottom.

5. The container of any one of the preceding claims, and having a dispensing adaptor in a pack with the container, the dispensing adaptor comprising complementary inner and outer members, the inner and outer members being arranged to bear against the inner and outer surfaces of the outer layer, respectively, around the opening, and thereby form an annular seal between the outer layer and the dispensing adaptor, the dispensing adaptor having a spigot for puncturing the bag and allowing the liquid to be dispensed.

6. The container of Claim 5, wherein the inner and outer members are arranged to be screw-fitted together.

7. The container of Claim 5 or 6, wherein, for sealing the dispensing adaptor against the outer layer, the dispensing adaptor has an annular recess of curved cross-section which faces axially, and a resilient O-ring for pressing against the opposite side of the outer layer to the annular recess and pressing the outer layer into the recess.

8. The container of any one of Claims 5, 2 or 7, wherein the inner member of the dispensing adaptor is not within the outer layer, but is insertable through the opening upon distortion of the sides of the opening.

9. A liquid container, substantially as herein described with reference to, and as shown in, Fig. 1 or Fig. 2 of the accompanying drawings.

10. A method of dispensing liquid wherein a liquid container is provided, the liquid container comprising a flexible, liquidtight bag containing the liquid and a flexible outer layer on at least one zone of the bag, and an opening is formed in the outer layer and a dispensing adaptor is fitted in the opening and sealed to the outer layer, the outer layer forming an otherwise liquid-tight compartment and the liquid being dispensed through the dispensing adaptor.

11. The method of Claim 10, wherein the liquid container is as claimed in any one of Claims 1 to 9.

12. The method of Claim 10 or 11, when the container has been made in accordance with Claim 18.

1 3. A method of dispensing liquid, substantially as herein described with reference to the accompanying drawings.

1 4. A machine for making liquid containers, the machine comprising: Feed means for feeding a first flexible material for making a series of bags and a second flexible material for making a series of outer layers, which second flexible material is provided with openings or means delineating openings: Sealing means for forming the first flexible material into a series of liquid-tight bags and sealing the second flexible material to at least one zone of each successive bag to form an outer layer thereon; Filling means for filling a liquid into each successive bag; and Cut-off means for cutting off the individual bags with the outer layers thereon.

1 5. The machine of Claim 14, and including means for forming the openings in the second flexible material.

16. The machine of Claim 14 or 15, comprising diametrically opposite, sprung spreader members over which the flexible material will pass in the form of a tube, for spreading out the tube to form a pucker-free shape of eleongate cross-section, and grippers for gripping the outside of the tube, at the end portions of the elongate cross-section, downstream of the spreaders, to pull the elongate cross-section out into a flat shape, the sealing means for sealing the ends of the tube being downstream of the grippers.

1 7. A machine for making liquid containers, substantially as herein described with reference to, and as shown in Figs. 4 and 5 of the accompanying drawings.

1 8. A method of making a flexible liquidtight container in an automatic or part automatic bag-making machine, the method comprising: Making a tube of flexible material; Passing the tube over diametrically-opposite, sprung spreaders which spread out the tube to form a pucker-free shape of elongate cross-section; Gripping the outside of the tube, at the end portions of the elongate cross-section, downstream of the spreaders, to pull the tube out into a flat shape; and Sealing the sides of the flat shape to each other.

19. A method of making a flexible liquidtight container in an automatic or part automatic bag-making machine,' substantially as herein described with reference to Figs. 4 and 5 of the accompanying drawings.

20. An automatic or part automatic bagmaking machine, for making containers out of flexible material, comprising: Diametrically-opposed sprung spreaders; Feed means for feeding a tube of flexible material over the spreaders so that the spreaders from the tube into a pucker-free shape of elongate cross-section; Grippers, downstream of the spreaders, for gripping the outside of the tube at the end portions of the elongate cross-section and arranged to pull the tube out into a flat shape by relative movement between the grippers; and Sealing means downstream of the grippers, for sealing the sides of the flat shape to each other.

21. The machine of Claim 20, wherein the spreaders and grippers are substantially as herein described with reference to, and as shown in, Figs. 4 and 5 of the accompanying drawings.

22. A container made by the method of Claim 18 or 19.