IE990734A1 - "Flexible collapsible container" - Google Patents

Abstract

A container (1) comprising a flexible body (2) which is collapsible and erectable, said body having a base (3) and a side wall (4), and stiffening means to stiffen the flexible body wherein the side wall (4) of the container (1) is arranged to assume a substantially cylindrical configuration when the container (1) is filled and the stiffening means comprises a unitary sleeve (5) of resiliently deformable material. The stiffening means is resiliently deformable about vertical axes, and is formed of a corrugated plastics material (30). The side wall (4) of the flexible body (2) is formed as an endless loop, for example as a unitary tubular or endless belt-shaped piece (12;13). The container is especially resilient to bursting or rupturing and is ideal for many materials including liquids. <Figure 1>

Description

Technical Field The invention relates to a collapsible container constructed of flexible material, particularly to a collapsible container suitable for storing/transporting flowable materials such as liquids, powders and fibres. “*1 It is often necessary or desirable to store or transport liquids. Steel drums or her rigid containers are conventionally used for this purpose. Steel drums, which are «v ;ry widespread in use, are not collapsible. Containers for liquids should be strong Qe lough to provide for maintenance of the physical integrity of the container, thereby Co wiating spillage and waste, but at the same time it is often necessary for a container to >?b ϊ transported empty. Transporting of empty containers is wasteful of space, and is -u Fn ω -H O r— Ή Cb $ O CA j-p transported in a much more compact and cost effective way. Collapsible containers are 3generally difficult to stack and handle when filled with a liquid. This is due at least in ' part to the tendency of the liquid to cause the flexible bag to balloon or bulge distorting the shape of the container. This creates problems with transporting, stacking and other handling problems. Furthermore collapsible containers rely to an extent on their contents to hold the container in its fully extended position by pressuring the walls (and base) of the container until the contents reach their limit of freedom, being constrained by the construction of the container. The walls of collapsible containers have little resistance to being pushed inwardly as they are designed to fold for collapsibility. The collapsibility of the container means that the container has a tendency to burst as force exerted on the walls is not absorbed by the structure of the container to any great extent, and the contents (which may be within a liner) within the container tends to receive a great deal of the force exerted on the walls so that the contents may burst from the container (or burst the liner).

Furthermore, due to the fact that the container constrains its liquid contents internal pressure of liquid, if sufficiently high, can cause seams/joints in the flexible container to rupture. Typical pressures have not been measured, but as the containers are designed typically to hold volumes of the order of a hundred litres or higher it will be appreciated that the forces are considerable. Taking the density of the liquid contents as being lkg/litre the weights involved are also of the order of 100kg or more. Bursting of the liner or rupturing of the container is most often observed when a filled collapsible container is dropped on its side or on its base. Impact on the ground creates a temporary, though dramatic, increase in pressure due to the downward movement of liquid. The increase in pressure can be sufficient to burst a liner holding the liquid (within the container) and/or rupture the container walls. While care is taken in handling such containers, occasionally an ill-stacked or accidentally bumped container may fall or be dropped onto the ground during handling. It is desirable that a container or liner does not burst or rupture in such a case. Typically, flexible containers dropped on their end from relatively low heights can rupture. Collapsible containers containing liners have been observed to burst spilling the contents when dropped from heights of 1 metre or less. While the above problem are most often observed for liquid contents, the problems occurs also with other flowable materials for example powders, slurries etc.

There is no commercially-available collapsible container which is substantially drum-shaped when erected/filled. The term drum-shaped is used herein to refer to a container with substantially cylindrical walls and a substantially flat base. Within the definition, the container may have a polygonal cross-section with n sides. Suitably n is an even number. To allow ease of folding of the container n is preferably six though n may be 8 or higher. It is desirable to provide a substantially drum-shaped container (in its erected/filled configuration) which is strong enough to withstand the punishments associated with handling, yet which is simple in construction. In particular it is desirable to provide a container which is resilient to rupturing when subjected to pressure or impact. It is also desirable to provide a lightweight container of simple construction which is easily collapsible yet having a relatively large internal volume which overcomes at least some problems of known containers. In particular it is desirable to provide a lightweight inexpensive drum-shaped container. For handling purposes it is desirable for the containers when filled to assume substantially identical shapes.

Background Art European patent publication no. 0 360 730 describes a flexible semi-bulk container that is suitable for use with fluidized solids, semi-solids, slurries and liquids and for shipping in less than truckload shipments where the package should have adequate stability to stand alone. The rigid panels are referred to as being constructed of hardboard, particle board, corrugated plastic, foamed plastic, solid state fibre and ply- board. The container described is square or rectangular in its erected configuration. Rigid panels are said to provide the necessary stability to allow the container to stand alone. In one embodiment the rigid panels form a four-sided sleeve. No drum-shaped container is contemplated. The problem of overcoming the tendency of the container described to retain its shape when filled is not discussed. Simplicity in construction and resilience to punishment are not discussed.

WO 97/20758 describes a container for storage or transport of liquids which has a flexible body which is collapsible and erectable. The body has a base and side walls with pockets therein. Stiffening members are provided in the pockets to stiffen the flexible body. The container is generally rectangular or square-shaped in its erected configuration. A transverse gusset is provided at each corner between adjacent side walls, and a reinforcer extends from the corner to the gusset - an arrangement which allows stackability as. a result of better retention of shape of the container due to its construction. While the construction achieves retention of shape of the side walls, there is no discussion of forming a drum-shaped container.

Other forms/methods of packaging are described in US 4,622,693 and US 3,896,991. EP 0,401,934 A describes a generally rectangular or square-shaped package for storing and transporting bulk goods. The package has an inner and outer frame which are partially attached to each other. EP 0,552,845 A describes a generally rectangular or square-shaped container having a relatively stiff form-retaining supporting frame and a flexible shell member. The supporting frame is necessary for retention of shape of the container.

None of the prior art documents discussed above provide a collapsible container which is drum-shaped when in its erected configuration. Furthermore as stated above it is desirable to provide a lightweight, collapsible container which can stand alone, yet which is resilient to bursting. Compactness on collapsing is also desirable. The shape of the base of the container in particular should be as planar as possible to allow stability in transporting, handling etc.. This is particularly the case where the contents are to be a fluid material, a liquid or indeed any flowable material such as powders or bulk fibres. It is desirable to have an inexpensive, lightweight, easily collapsible container which is resistant to bursting.

Disclosure of Invention It is an object of the invention to provide a container which retains its desired shape on filling. It is particularly desirable to provide a drum-shaped collapsible container which achieves this objective and which is suitable for storing or transporting fluid material in bulk and which is also collapsible to a storable or folded configuration yet which can stand alone. In particular it is desirable that the container should not require the aid of an external stand or prop while being filled and the containers should be transportable, for example when standing on a pallet, without the contents of the container causing an upset or instability of the container. The container should be resilient to bursting or rupturing, yet lightweight.

According to the invention there is provided a container comprising a flexible body which is collapsible and erectable, said body having a base and a side wall, and stiffening means to stiffen the flexible body, wherein the side wall of the container is arranged to assume a substantially cylindrical configuration when the container is filled and the stiffening means comprises a unitary sleeve of resiliently deformable material. The sleeve of resiliently deformable material adopts the same substantially cylindrical configuration as the side wall. Suitably, the stiffening means is resiliently deformable about vertical axes. This arrangement allows the container to flex under internal pressure from its contents. Flexing of the container allows it to substantially assume a drum-shape i.e. the provision of the resiliently deformable stiffening means allows the side wall of the container to conform to a substantially cylindrical shape. Suitably, the stiffening means or component is formed of corrugated plastics material. In a preferred arrangement the longitudinal axes of the corrugations are substantially aligned, running substantially parallel to a line between the base and top of the container i.e. (substantially perpendicular to the base) This construction of container has a number of advantages: The container is lightweight, yet robust and sturdy. The container is of very simple construction yet can withstand substantial pressures and impacts. In particular the container is resistant to rupturing when dropped. The container also provides good support for a liquid-retaining envelope member or liner placed within it, helping to prevent it bursting. The stiffening means tend to flex to allow the container to take up a drum- shape. The container shows good ability to retain its shape. Containers tend to have substantially the same shape when filled, forming collapsible drums of veiy similar diameter.

In one embodiment the sleeve of reiliently deformable material is scored or folded to provide hinge lines or fold lines about which the sleeve can fold.

In a very robust arrangement the side wall of the flexible body is formed as a single piece, more especially an endless loop, for example as a unitary tubular or endless belt-shaped piece. The combination of the sleeve being formed of a unitary body and the side wall of the container being formed as an endless loop gives the container very desirable strength and resistance to rupturing. The absence of seams or joints on the side wall and not more than one joint on the sleeve gives the container enhanced strength, and resistance to rupturing. This ensures that a liner placed in the container will receive better (stronger) support from the container, and furthermore the container itself will be less likely to rupture.

For woven materials forming the side wall, the material may be woven in a single piece as a tube or hoop. For extruded materials, the materials may be extruded as a tube or hoop. Similarly, the sleeve may be formed as a unitary seamless/joinless piece or may have one secure joint.

In one simple construction, the stiffening means is attached to the interior of the body for example by stitching. This very simple structure is surprisingly robust and yet lightweight.

In a preferred embodiment the side wall is double-layer wall conferring even greater strength.

In one embodiment, a double layer side wall is formed by two separate tubes of flexible material, one tube arranged (concentrically) inside the other. In an alternative embodiment, the double-layer side wall is formed by one piece of flexible tubular material which is doubled upon itself. Either arrangement provides a very simple and high strength construction.

In a preferred arrangement, at least a portion of the side wall extends upwardly to form a flexible closure for the mouth of the container. In a preferred arrangement, the side wall comprises a double-layer side wall and the flexible closure is formed by a portion of at least one of the layers. Preferably the outer layer of the side wall forms the flexible closure, but it is also possible for the inner layer to do so.

In one arrangement the flexible closure is provided with a closure means in the form of a tie to hold the flexible closure in a closed position. In one arrangement the tie is a drawstring on the flexible closure to draw the flexible closure closed.

In one simple construction, the container of the invention comprises a flexible body which is collapsible and erectable, the body having a base and a side wall, theside wall being a double-layer side wall of tubular flexible material, and a unitary sleeve of resiliently deformable material for stiffening the flexible body, the double-layer side wall being attached to the sleeve, preferably a lower (base) and upper (top) end of the sleeve, and a portion of one layer of the side wall forming a flexible closure for the mouth of the container. Suitably a protective bib or flap is provided on the container for protecting the top of a liner or container placed within the container. In each construction of the container or pack of the present invention the base may be formed of a separate piece of flexible material.

In a preferred embodiment the container has a body of flexible material such as that used hitherto for flexible intermediate bulk containers, e.g. a fabric such as woven polypropylene which is stitchable or a material which is weldable.

In one construction the container has a liner therein, particularly a liquid impermeable liner e.g. of co-extruded plastic film such as polyethylene, conforming to the interior configuration of the body. A container may for example have an octagonal cross-section. Usually, the container has one or more lifting loops.

The invention also relates to a pack comprising an outer container comprising a flexible container of the invention having inserted therein a collapsible and erectable liquid impermeable inner container comprising: (i) a flexible body having a base and side walls and a top wall; and (ii) an inlet in said body; and (iii) closure means for closing said inlet, the inner container being drumshaped. There is thus provided a drum-shaped outer container for holding a drumshaped inner container.

The flexibility of the container body allows it to be collapsible and erectable so that the inner container can be folded flat yet desirably is sufficiently rigid to stand alone when being filled. In one arrangement the inner container body is transparent or translucent. Suitably the inner container is constructed of plastics material such as polyethylene. In one embodiment the inlet is in said top wall of the body, preferably recessed therein (for instance the inlet may be formed in a depression in the top wall). Suitably the inner container is dimensioned to be a snug fit within the container of the invention when the inner container has been filled.

The invention extends to a bulk container or pack substantially as described herein with reference to and as illustrated in the accompanying drawings.

Brief Description of Drawings A container embodying the invention is hereinafter described by way of example, with reference to the accompanying drawings.

Figure 1 is a perspective view of a container of the invention in an erect condition (with the stiffening means of the invention in place) with a flexible closure for the container upstanding on the container, the container being suitable for use to hold an inner container shown in Figure 6 below: Figure 2 is a perspective view from below and one side (with the top part of the container cut-away) of the container of Figure 1; Figure 3 is a perspective view of the stiffening means of the invention in the form of a sleeve of octagonal cross-section; Figure 4 is a perspective view of a mode of construction of part of the container of Figure 1.

Figure 5 is a part sectional view of a side of the container illustrated in Figure l; Figure 6 is a perspective view of an inner container for use in a pack of the invention in a erected configuration (standing alone), and with a cap closing the inlet in the container; Figure 7 is a perspective view of the container of Figure 6 in a collapsed configuration; Figure 8 is a perspective view of the container of Figure 6 partially inserted into the container of Figure 1; Figure 9 is a perspective view of a pack comprising an outer container being the container of Figure 1 and inner container being the container of Figure 6, the pack having been closed; and Figure 10 is a perspective view of the container of Figure 1 in a collapsed or folded configuration.

Modes for Carrying out the Invention Referring to the drawings, there is shown a container 1, comprising a flexible body 2 of constructed of a flexible fabric which is collapsible and erectable. The body 2 has a base 3 ( Fig. 2) and has a side wall 4 composed (in the embodiment illustrated) of a unitary piece of flexible material which takes up the shape of the stiffening means in the form of a sleeve 5, so as to confer an octagonal shape of eight similar wall portions. An elongate stiffening member or sleeve 5 having an upper (top) end 6 and a lower (base) end 7 stiffens the flexible body 2. The lower end 7 of the sleeve 5 is disposed proximate the base 3 while the sleeve 5 extends upwardly along the container 1 so that the upper end 6 of the sleeve is located near to the top 8 of the container 1.

The container 1 has a flexible base sheet 9 (Fig. 5) of heavy duty material which extends across the container to form the base 3 of the container. The base sheet 9 is arranged so as to be taut in the erect configuration of the container. The base sheet 9 is stitched on a stitch line 10 to the bottom 11 of the side wall 4. The base sheet has an area substantially equivalent to that of a horizontal cross-sectional area of the erected container and can take up loading. In the embodiment shown the sheet 9 is a double layer sheet. There is no slack inner sheet of flexible material extending across the interior of the container above the base.

The flexible body 2 is formed by a double layer side wall. The double-layer side wall may be two separate (cylindrical) tubes of flexible material brought together. The tubes are formed from endless loops or belts of flexible material. In the embodiment shown (see in particular Figures 4 and 5), the double-layer side wall forming the flexible body 2 comprises two tubes of material, one inserted (concentrically) in the other, to form a double tube arrangement comprising an inner tube 12 and an outer tube 13. As best seen in Figure 4 the outer tube 13 is longer than the inner tube 12. The extra length of outer tube 13 is used, in a manner to be described below, to form a flexible closure for the container. The sleeve 5 is inserted into the inner tube 12, and the sleeve 5 and the inner tube 12 are both together inserted into outer tube 13 in the direction indicated by the arrows. The inner tube 12 and outer tube ίο are adjusted until their lower ends, respectively labelled 26 and 27, coincide as shown in Figure 4. As best seen in Figure 5 the lower ends of the tubes 12,13 are placed to the interior of the sleeve 5 and folded in a general u-shape about the lower end 7 of the sleeve 5 running upwardly to form side wall 4. Tubes 12 and 13 are seamless, being woven in a tubular form. The (dual) stitch line 10 is stitched right through the body 2 of the container, and the sleeve 5. In particular the stitch line 10 holds the sleeve 5 in place within the container, while simultaneously using the sleeve 5 as a mount or base for the flexible body for formation of the container. The double-ply layer comprising the inner tube 12 and the outer tube 13 then travels the length of the sleeve 5 until it reaches the upper end 6 of the sleeve 5. The inner tube 12 and the outer tube are then both folded about the end 6 of the sleeve 5 in a generally U-shaped arrangement. A stitchline 14 passes through the fold of inner and outer tubes 12,13 on both sides of the sleeve 5, and right through the sleeve 5, to hold the double-ply layer to the sleeve. As described above the inner tube 12 is shorter than the outer tube 13 and terminates at its upper end 15 folded inside the mouth of 16 of the container. The outer tube 13 turns down into mouth 16 of the container 1, folds back upon itself at fold 17, and then turns in an upwardly direction to form a flexible closure 18 for closing the mouth 16 of the container 1. The fold in outer tube 13 is held in place by the stitch line also. The outer tube 13 continues upwardly and folds upon itself once again at fold 19.

The outer tube 13 folds downwardly and inwardly at fold 19 and is stitched to itself by a stitch line 20. The top edge portion of the outer tube 13 thus forms a seam, channel or duffel 21 through which a drawstring 22 is threaded. It will be noted that outer tube 13 is split along part of the length of the flexible closure 18 to allow drawstring 22 to draw the flexible closure 18 closed. The drawstring 22 acts as a tie to draw closed the flexible closure 18 across the mouth 16 of the container. A piece of material which forms a flexible protective bib 23 is also held internally by the stitch line 14. The protective bib 23 extends across and protects the closure of a inner container which is inserted in the container in the manner to be described below. A single handle 24, formed by a elongate piece of flexible material in the form of a strap, is stitched by heavy duty zigzag stitching 25 to the exterior of the flexible body 2 on opposing sides π thereof. The lifting strap or handle 24 can be used to raise the container (when filled), using for example a fork-lift truck.

As can be seen from Figures 1, 2 and 8 in particular the sleeve 5 confers a substantially octagonal shape on the flexible body 2. The sleeve 5 is shown in Figure 3. The sleeve 5 consists of a unitary piece of corrugated plastics 30. The sheet of corrugated plastics 30 has been folded about eight, equally spaced apart fold lines 31, which give the sleeve 5 its generally octagonal shape. It can be seen from the Figures that the folding of the plastic material is arranged so that the axes of folding of the corrugations 32 run along the walls of the sleeve 5 following a line from the upper end 6 of the sleeve to the lower end 7. In the configuration shown in Figure 3 a first end 33 has not yet been joined to a second end 34 of the sheet 30. An inturned rim 35 between a fold line 31 and the second end 34 is used as a seam which is overlapped with the first end 33 so that the sheet of corrugated plastics 30 may be formed into a single piece. Joining of the ends of the sheet may be achieved for example by heat welding at welding points 36. Alternatively the ends may be joined by any other suitable method, such as for example stitching, adhesion etc. It is preferred however that the sleeve 5 is formed as a unitary (endless) piece, rather than created by joining, for example joining the ends of a sheet.

An inner container 40 useful to form a pack with a flexible outer container 1 of the present invention is shown in Figure 6. The inner container 40 is made of polyethylene transparent plastic material. The inner container 40 comprises a collapsible and erectable body 41 which, in the embodiment illustrated, has sufficient strength to stand alone.

The body of the container 40 has a side wall 42 which is formed by a generally cylindrically shaped wall. The inner container body 41 has a base 43 and a top wall 44. In its erected configuration the container 40 has a generally cylindrical or drum-shaped appearance. A product inlet/outlet 45 is formed in a depression or recess portion 46 in the top wall 44. Closure means, in the form of a screw-on cap 47, is shown having been screwed on the reciprocal threads in the product inlet/outlet. The cap 47 is removed for filling or emptying product into or from the container. The inner container 40 is liquid impermeable being generally designed to hold and store liquids (and fluidized products) without leakage.

The inner container 40 useful in the present invention is designed to form a pack with the outer container 1 of the present invention. In particular the container 40 forms an inner container of the pack as will be described below. This arrangement is shown in Figure 8. It would be appreciated that liners may be used with the container 1 of the present invention for example a liquid impermeable liner or for example a coextruded plastics film such a polyethylene which conforms to the inner configuration of the body. It will be appreciated as well that the container 1 may be used without a liner. The inner container 40 is particularly advantageous where the material to be handled is a liquid.

To form the pack comprising the container 1 as an outer container and the container 40 as an inner container the flexible closure 18 is raised to an upstanding position from the body 2 (such as shown in Figures 1 and 8). The drawstring 22 is loosened so that the closure 18 gapes to form a neck or opening 37 through which the inner container 40 is inserted, base first. In the configuration shown in Figure 8 the lifting handle 24 has been moved to one side to avoid obstructing insertion of the inner container 40. The bib 23 has been pulled upwardly along the flexible closure 18 so that it may be placed on top of the container 40 when the container 40 is fully in place.

In use, container 40 is fully inserted to form a inner container of the pack, the cap 47 is removed and liquid product pumped into the inner container 40. The filled pack comprising the outer container 1 and the inner container 40 is shown in Figure 9. The bib 23 has been pulled across the top wall 44 of the container 40. In particular the bib 23 protects the cap 47 of the inner container . The drawstring 22 is pulled.closed over the inner container 40 and the bib 23, and tied together in a releasable knot 50. The filled container can be easily moved by use of the lifting handle 24.

As can be seen from Figure 9, the container 1 flexes (due to the resiliently deformable nature of the sleeve 5) to take up a drum-shaped appearance under the weight of the contents of the inner container 40.

Figure 7 shows the inner container 40 of Figure 6 in a collapsed configuration. The side walls 42 of the container have folded/collapsed so that the inner container body 41 folds or concertinas, so that the top wall 44 and the base 43 remain substantially parallel to each other.

It will be noted that the container 40 is of sufficient strength to stand alone as shown in Figure 6, but is also sufficiently flexible to expand under the weight of its contents causing the body 2 to take up a cylindrical shape. The inner container is constructed of suitable plastics to make it strong, resistant to creasing and pin-holing. For example the inner container 40 may be of a type of flexible container available under the trademark “Flexotainer”® from Nittel in Germany. This type of inner container is not conventional to flexible intermediate bulk containers.

The body 2 may be made from flat or circular woven textiles, such as polypropylene, as known for flexible intermediate bulk containers, or any other suitable material. If necessary, the polypropylene is stitched to form the octagonal-in-plan shape shown.

An empty container 1 can be folded (collapsed) as shown in Figure 10. The container 1 is emptied if not already empty. The inner container 40, if present, can be first removed, though the container may be folded with the inner container 40 in place. The flexible closure 18 is, for the sake of neat packing of the container, folded into the container. The container is then folded about the hinge lines 31 of the sleeve 5 so that two hinge lines 30 move towaids the centre of the folded arrangement. The folded container 1 is then substantially flat in configuration, having a width, corresponding to the width of two of the eight sides of the octagonal shape. The strap 24 may also be held neatly within the folded structure. There is no necessity to remove the sleeve 5. It will be appreciated that only six fold lines are required to collapse the container into a neat stowable configuration.

To erect a pack of the invention the user has merely to open the container to the shape shown in Figure 1 by pulling out two opposing sides, inserting an inner container 40 if necessary, and commencing filling of the contents thereinto. The container can be placed on a pallet, after opening out. The rigidity of the sleeve and the flexibility of the fabric ensures ready movement between the collapsed and erected conditions, the stitching and sleeve ensuring that the unfilled yet erected container maintains its rigid shape prior to filling. The substantially octagonal cross-section of the erect container is pressured into a substantially circular cross-section on filling with contents (such as liquids or fluidized material) which apply pressure evenly about the internal perimeter of the container.

The base sheet 9 may be formed of a separate piece of material. The base sheet 9 is stitched into the container 1 by stitch line 10 or by separate stitching if required. A variety of closures could be used with the container of the invention.

The inner container 40 may be constructed of polyethylene or polypropylene. If conventional liners constructed of plastics film are used, glands for filling and/or emptying the liner could also be provided. The glands could be secured to apertures in the top or front. If a conventional liner is used, for example one constructed of a plastic film, in order to ensure that the liner takes up, and conforms to, the interior configuration of the container body, the liner, after insertion and connection of the glands, is inflated, then deflated suitably by collapsing the container 1 to the collapsed, flat shape. The liner thus conforms to the body shape of the container 1 in its erect mode and takes up the substantially octagonal configuration of the interior volume of the container.

An aperture may be provided in a side wall for a discharge outlet. A planar member may be removably inserted in the base 3 to strengthen the container.

It has been discovered that corrugated plastics material is particularly useful in the container of the present invention. One example of such material is corrugated polypropylene. The stiffening means may be for example a cylindrical (or polygonal e.g. octagonal) sleeve. The sleeve 5 collapses about a longitudinal axis.

In one construction the container had the following dimensions : Height of outer container approx 90cm Diameter of erected filled container approx. 57 cm The inner container was a flexible container supplied under the trademark, Flexotainer ® with the following dimensions: Diameter - 570 mm; Height - 834 mm.

Typical capacities of the pack or outer container of the present invention are about 200 250 litres, though it will be appreciated that any desired volume can be achieved, suitably from 25 litres upwards to 1,000 litres.

Example A pack having the dimensions given above and a Flexotainer ® was assembled as shown above. 200 litres of liquid (water) were filled into the Flexotainer ®. The pack was closed to the configuration of Figure 9. The pack was subjected to the following tests: The pack was dropped vertically from the following heights onto the ground, -base first: 1.8m (three times) 2.5m (once) The pack did not rupture. Neither the inner nor the outer container burst.

As an alternative to the single handle (lifting loop) 24, it may be desirable to use two lifting loops, suitably sewn to the exterior of the body at four-points spaced equally around the perimeter. The sewing points for each loop may be adjacent to one another or they may be located opposite to each other, suitably diametrically opposite, in which case, one loop crosses over the other and the loops may be joined together at the mid point of each. 16 If desired, a small discharge chute may be provided for discharging from the bottom of the drum.

The words “comprises/comprising” and the words “having/including” when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims (25)

1. A container comprising a flexible body which is collapsible and erectable, said body having a base and a side wall, and stiffening means to stiffen the flexible body wherein the side wall of the container is arranged to assume a substantially cylindrical configuration when the container is filled and the stiffening means comprises a unitary sleeve of resiliently deformable material.

2. A container according to claim 1 wherein the stiffening means is resiliently deformable about vertical axes.

3. A container according to claim 1 or 2 wherein the stiffening means or component is formed of a corrugated plastics material.

4. A container according to claim 3 wherein the longitudinal axes of the corrugations are substantially aligned running substantially perpendicular to the base of the container.

5. A container according to any preceding claim wherein the sleeve is a jointless body.

6. A container according to claim 5 wherein the sleeve is scored or folded to provide hinge lines or fold lines about which the sleeve can fold.

7. A container according to any preceding claim wherein the side wall of the flexible body is formed as an endless loop, for example as a unitary tubular or endless beltshaped piece.

8. A container according to any one of the preceding claims wherein the stiffening means is attached to the interior of the body, for example by stitching.

9. A container according to any one of the preceding claims wherein the side wall is a double-layer side wall.

10. A container according to claim 9 wherein the double-layer side wall is formed by two separate tubes of flexible material, one tube arranged inside the other.

11. A container according to claim 10 wherein the double-layer side wall is formed by one piece of flexible tubular material which is doubled upon itself.

12. A container according to any preceding claim wherein at least a portion of the side wall extends upwardly to form a flexible closure for a mouth of the container.

13. A container according to claim 12 wherein the side wall comprises a double-layer side wall and the flexible closure is formed by a portion of at least one of the layers.

14. A container according to claim 13 wherein an outer layer of the side wall forms the flexible closure.

15. A container according to claims 12 to 14 wherein the flexible closure is provided with a closure means in the form of a tie to hold the flexible closure in a closed position.

16. A container according to claim 15 wherein the tie is a drawstring on the flexible closure to draw the flexible closure closed.

17. A container comprising a flexible body which is collapsible and erectable, the body having a base and a side wall, the side wall being a double-layer side wall of tubular flexible material and a unitary sleeve of resilient deformable material for stiffening the flexible body, the double-layer side wall being attached to the sleeve and a portion of one layer of the side wall forming a flexible closure for a mouth of the container.

18. A container according to any preceding claim wherein a protective bib or flap is provided on the container for protecting the top of a liner or inner container placed within the container.

19. A container according to any preceding claim which has an octagonal cross-section.

20. A container according to any preceding claim having one or more lifting loops.

21. A pack comprising a outer container having the features of a container according to any preceding claim having inserted therein a collapsible and erectable liquid impermeable inner container comprising: (i) a flexible body having a base and side walls and a top wall; and (ii) an inlet in said body; and (iii) closure means for closing said inlet, said inner container being drumshaped.

22. A pack according to claim 21 wherein the inlet is in said top wall of the body, and preferably is recessed therein.

23. A pack according to claim 22 wherein the inner container is dimensioned to be a snug fit within the outer container.

24. A pack according to claim 23 wherein the inner container when holding a flowable product presses the outer container into its cylindrical wall shape.

25. A container or pack substantially as described herein with reference to and as illustrated in the accompanying drawings.