GB2185732A - Container - Google Patents

Abstract

A flexible walled container 1 having a capacity of at least 100 kgs of a granular or fluent particulate material and which is provided with one or more loop-like members 22 adapted to be engaged from alongside and/or above the container by a lifting means, is characterised in that substantially all of the container or all but the basal portion of the container is enclosed in a water-resistant outer cover 20 which also encompasses the loop-like members, the cover being formed with apertures 21 which are configured to lie within the loop-like members so as to permit the lifting means to engage the loop-like members, the periphery of each aperture being formed as a closure to preserve the integrity of the cover. <IMAGE>

Description

SPECIFICATION Container The present invention relates to a container, notably to a bulk container for particulate materials.

Many particulate materials are packed into sacks, bags and the like fortransport and storage and it is customary to load such sacks onto a pallet or other load-bearing platform for handling. Whilst such a loaded palletenablesa numberofsackstobe handled at once, it is still necessary to fill and handle individual sacks in making up the loaded pallet. In orderto reduce the amount of handling requiredto move a given weight of material, the capacity ofthe individual bags and sacks has been increased until at present they can contain up to 2000 Kgs of material.

For convenience, such large capacity bags will be called IBCs hereinafter.

In orderthat an IBC can be handled mechanically, it has been proposed to provide it with loops attached thereto by which it can be lifted from above; orto provide it with a separate or integral pallet upon which it can be lifted from below. This enables the IBCs to be handled and stacked using aforklifttruck or similar.

However, where a lower IBC in a stack is ruptured, it may lead to partial collapse of the stack. Where the IBC is mounted on a pallet, the partial collapse ofthe stack will often cause the pal lets to tilt. As a result, the tines of the fork liftwill no longer register with the fork entry points in the pallet and it becomes impossible to unload the stack mechanically. On the other hand, IBCswith lifting loops can be handled even when they are at an angle.

With IBCs, problems are also encountered in keeping the contents of the IBC dry and free-flowing. The walls of the IBC can be made from an impervious material, such as heavy duty polyethylene sheeting, and the foot of the IBC can be re-inforced. However, the IBCwalls are readily punctured by the contents. It has therefore been proposed to wrap the complete IBC and pallet in a water-proof outer container and to shrinkwrapthat onto the IBC to form a closed weather-proof cover. Such an assembly can still be handled since the fork lift tine entry points on the pallet are still accessible. However, there is still the problem of dismantling a stack if a lower IBC should rupture.With IBCs having lifting loops, it has hitherto been considered impossibleto provide them with a weather-proofoutercover,sincesuch a cover must extend over the top of the IBC if it is to be effective and will therefore enclose the loops by which the lBC is to be lifted and deny access to the tines ofthefork lift truck.

We have now devised a method by which IBCs having lifting loops can be rendered weather resistant and yet access to the lifting loops is retained.

Accordingly, the present invention relates to a bulk bag provided with one or more loop-like members adapted to be engaged from alongside and/or above the bag buy a lifting means, characterised in that substantially all ofthe bag orall but butthe basal portion of the bag is enclosed in a water-resistant outer cover which also encompasses the loop-like members, the cover being formed with apertures which are configured to lie within the loop-like members so asto permitthe lifting means to engage the loop-like members, the periphery of each aperture being formed as a closure to preserve the integrity of the cover.

The invention also provides a method for rendering water-resistant a bulk bag having loop-like members whereby the bag is adapted to be lifted, which method comprises: a) applying to the bag an outerwater-resistant cover memberto enclose substantially all of the bag orto enclose all but the basal portion ofthe bag, and to encompass the loop-like members, b)forming one or more aperturesthroughthe cover and configured so asto liewithin the loop-like members, and forming a closure around the periphery of the apertures whereby the water-resistant properties of the cover are substantially maintained.

The bag to which the invention can be applied can be of any suitable shape, cross-section, size and configuration. The term is used hereinafter to denote in general sacks, bags and other flexible walled containers having a capacity of at least 100 kgs of a granularorfluentparticulate material.

The invention enables bags with lifting loops to be used in conditions where hitherto they have had to be provided with protection againsttheweather and yet retains the handling advantages of a bag having a top lift facility.

The method and the bag of the invention find use wherever it is desired to render a bag having lifting loops water-resistant, for example in the storage and handling of foodstuffs and chemicals. The invention is of especial use with bags containing particulate fertilizers. For convenience, the invention will be described hereinafter with respect to such a preferred use.

Preferably, the bag is formed from a woven syntheticfibre or filament, notably from woven polypropylene or polyethylene fibres. The lifting loops can be provided by a separate sling or cradle extending axially around the bag. However, it is preferred that the lifting loops be formed integrally with the walls of the bag, eg. by extending opposed sides ofthe bags walls and joining those extensions together above the body of the bag, by weaving strips of material into the bag wall or by stitching, glueing or otherwise fixing strips of suitable material to the bag wall so that loops are formed standing proud above the upper face of the filled bag.

Where the base of the bag is adequately water resistant, the outer cover can be formed as a single section which extends over the top of the bag and the lifting loops and extends downwards to or adjacent to the base of the bag. Preferably, such a single section cover also extends partially over the base face of the bag so that when the cover is shrunk onto the filled bag it forms a partial cover to the base of the bag and reduces the risk of water seeping underthe bag and permeating through the base of the bag. As indicated below, the use of a cover which does not totallyencasethebag aids escape of air during filling ofthe bag,andyetwe havefoundthatsuch an incomplete cover provides adequate weather protection to the contents of the filled bag.

Alternatively, the outer cover can be formed as two sections, a basal section encasing the base ofthe bag and an upper section encasing the upper portion of the bag and extending upwardlyto enclose the lifting loops, so as to provide an outer coverwhich totally encases the bag.

The outer cover is preferably made from a heat sealable material, eg. a polyalkylene sheet material, and the apertures through the outer cover at the lifting loops are formed by bringing togetherthe walls of the cover lying to each side ofthe plane ofthe loop, cutting outthe material from the outer cover walls within the confines of the loop, and sealing together the edges of the material around the cut away portions to form a seal around the aperture.

To aid understanding ofthe invention, it will described hereinafter with respect two a preferred form ofthe bag as shown in the accompanying drawings in which Figure lisa diagrammatic persp ective view of a bag with the basal and upper sections ofthe cover partially in position; Figure2 shows the bag of Figure 1 with the cover in position; Figure3shows in greater detail the area ofthe lifting loops of the bag of Figure 2; and Figures 4and 5 show an alternative form ofthe bag of Figure 1.

The bag 1 comprises a conventional bulk bag hav ing a capacity of from 250 to 1500 Kgsofgranular fertilizer. Typically, the bag will have a generally square cross-section and the bag wall is made from a woven polypropylene fibre.

Preferably,the bag has an innerliner2formed from a polyethylene, PVC or other polymer sheet material or the like, which may be a composite or laminated material and may be separated from or integrai with the wall ofthe bag 1. This linerorthe interior of the bag 1 can be provided with a cruciform shaped internal partition 3 to assistin retaining the shape ofthe bag during filling. lfdesired, and prefer ably when no inner liner 2 is present, the base 4 of the bag can be reinforced to resist puncturing by the contents ofthe bag or by stones.

The bag and liner have an open top oraperture,eg.

afilling spout atthe top orside arm as shown in Figure4,throughwhichtheycan befilled and means whereby the bag or aperture can be closed off when the bag has been filled, eg. byfolding over or by forming a swan neck at the open top or the end ofthe spout and tying that off, or by stitching, glueing or by heat sealing the open end to the liner or spout closed.

The bag is provided with lifting loops, which preferably extend above the top face of the bag so that they can be engaged bythetines of a fork lift truck or other means fortop-lifting the bag. However, the lifting loops can extend laterally from a point part way upthe height ofthe bag, so thatthey are engaged by the tines of a fork lift passing to either side of the bag rather than as a top lift.

It is preferred to form the lifting loops integrally with the bag, notably by extending two opposed side walls 5,6 ofthe bag beyond the top face ofthe bag and joining the free ends of those extensions togetherto form a single lifting loop 7. Alternatively, the loops 7 can be formed from straps of suitable webbing orthe like attached to the bag. Thus, polye- ster or similar webbing straps can be stitched onto the bag to form a cradle passing underthe bag with the free ends ofthe webbing joined together above the bag to form two or more loops 7 standing proud above the bag. The loops can be crossed above and belowthe bag to provide a lifting loop which can be engaged from any direction. If desired, the lifting loops 7 can be provided with stiffening or other means to cause them to adopt an upstanding position.

The bag is encased within an outer water-resistant cover 10. As shown in Figure 1 ,this can beformed in two sections: a base section 11 into which the base of the bag 1 seats; and an upper section which fits over the upper portion ofthe bag and the lifting loops 7. However, as indicated above and as shown in Figures 4 and 5, where the base of the bag is sufficiently strong and water resistant, the basal section can be omitted so that the outer cover is provided by a single upper portion extending to or close to the base ofthe bag. In the above cases the top of the upper portion will be closed, eg. by being heat sea led or otherwise closed off.However, it is also within the present invention to form the outer cover as a single member having a closed lower end into which the bag is fitted base first, the open end ofthe outer cover then being sealed or otherwise closed above the lifting loops to form a water-resistant envelope around the bag.

The outer cover can be provided as a separate member or members which are mounted upon the bag at the filling location. Alternatively, the outer covercan be mounted onthe empty bag during manufacture ofthe bag, so that a preformed unit is provided to the filling location. For example, with the form of cover shown in Figure 4, a bag 1 can be encased in a suitable outer cover 20 and the apertures 21 formed within the compass of the lifting loops 22 underfactory conditions to provide atotally sealed, but empty, bag construction.

Preferably, the outer cover is a loose fit around the bag to facilitate application of the cover to the bag and, when applied as a base and an upper section at the filling location, the sections overlap one another to provide a weather-proof overlap atthe junction of the two sections. The two sections can be joined at the overlap by any suitable method, eg. heat welding or adhesive to complete the outer cover before or afterfilling of the bag. We have found thatwherethe outer cover is heat shrunk onto thefilled bag this usually forms a satisfactory closure between the upper and lower portions ofthe outer cover.

As indicated above, problems due to entrapment of air between the bag and the outer cover may occur with an outer cover which totally encloses the bag.

We therefore prefer two provide meanswherebythe air can escape during filling ofthe bag. As shown in Figure 5 this can take the form of vent apertures 25 in the cover wall 20. These apertures can be provided with closure flaps 26to inhibitthe ingress of water and/or with a circumferential sealing strip 27 which isshrunkontothefilled bag. However,wehave found that adequate weather-proofing ofthe bag can be achieved by the use of an outer cover which does not extend fully overthe base ofthe bag and thatthe use of such an open based cover 20 provides a simple and effective meansforventing the air during filling of the bag.As shown in Figure 5, the outer cover can extend 2 to 10 cms onto the periphery of the base of the filled bag, for example as a result of heat shrinking the cover onto the filled bag, and this serves to inhibit penetration of rain water undern- eath a bag and also to secure the outer cover onto the bag.

The outer cover 10 or 20 is conveniently made from a thermoplastic polymeric sheet material, eg. a polyethylene or polypropylene, although other materials, for example laminated, woven or reticulate materials, can be used if desired.

The outer cover encompasses the lifting loops and the opening contained within the loop through which the lifting means are to be passed when the bag is lifted. The material ofthe outer cover is cut away within the area of the opening to form apertures through the outer coverthrough which the lifting means can be passed to engage in the lifting loops. The edges 30 of the material around the apertures are sealed or otherwise fixed together to close the outer cover and thus retain the integrity of the outer cover envelope. This can be done by heat sealing, glueing, stitching or otherwise sealing together the severed edges of the outer cover material.In a particularly preferred method of operation, the walls of the cover are brought together by a heat sealer/ cutter bar having the desired shape to form the aper turves 31 and seal the severed edges 30 in a single operation. Where the outer cover is applied to the bag during manufacture of the bag,the clean conditions obtainable in a factory environment aid formation of a good seal.

The apertures can extend substantially to the full extentoftheopening ofthe looporcan be smaller if desired. If requ ired, a secondary or re-inforcing seal can be formed around the periphery ofthe apertures to strengthen the rim of the aperture. The optimum position and size of the aperture will depend upon the size, shape and weight of the bag and the lifting loop sothatthefilled bag can be lifted by the lifting loop without rupturing the outer cover 10 or20,and can readily be determined by simple tests.

As indicated above, the bag is provided with means whereby it can be filled. Where the outer cover is fitted after filling ofthe bag,thefilling and closure of the bag can be achieved by conventional methods prior to fitting the outer cover. Where the cover is fitted before filling, it will usually be necessaryto provide an aperture in the outer cover throughwhichthefilling spoutfrom the bag can be accessed from the filling machine. Thus, as shown in Figure 4, the filling spout 23 ofthe bag or its liner can protrude through an aperture 24 in the wall ofthe outer cover 20. Preferably, the aperture 24 is orienta ted axially on the cover so that it is subjected to the minimum stress when the filled bag and cover are lifted.

seal.

The bags ofthe invention are filled using convent ional techniques, for example through thefilling spout 24. The outer cover 20 is applied to the bag either before or after filling. In the former case, the spout 23 will extend through an aperture 24 in the coverwall and is sealed off and tucked underthe outer cover and the aperture 24 sealed off afterfilling. When the bag has been filled, the cover 20 is preferably heat shrunk onto the bag to form a secure and weather-proof cover to the bag.

The invention has been described above in terms of a bag which isto be lifted by means of lifting loops. However, the invention can also be applied to bagswhich are mounted upon a palletorotherloadbearing platform to permit base lifting as well as top lifting via the lifting loops. In this case, as shown in Figure 2,the platform 40 can be located withinthe outer envelope 10 and the apertures required to permit access ofthe fork tines into the lifting ports of the pallet, are sealed against the pallet around the mouth of the entry port using a suitable adhesive.

The bags ofthe invention find use wherever it is desired to handle or store materials which could be affected by their environment, notably for storage of materials outside, eg. on a farm. The bags can be filled, handled and stored as if they were conventional top lift bags.

Claims (20)

1. Aflexiblewalled container having a capacity of at least 100 kgs of a granularorfluent particulate material and which is provided with one or more loop-like members adapted to be engaged from alongside and/or above the container by a lifting means, characterisedin thatsubstantial ly all of the container or all but the basal portion of the container is enclosed in a water-resistant outer cover which also encompasses the loop-like members, the cover being formed with apertures which are configured to lie within the loop-like members so as to permitthe lifting means to engage the loop-like members, the periphery of each aperture being formed as a closure to preserve the integrity of the cover.

2. A method for rendering water-resistant a flex iblewalledcontaineraccordingtoclaim 1 having a capacity of at least 100 kgsofa granularorfluent particulate material said container having loop-like members whereby the container is adapted to be lifted, which method comprises: a) applying to the container an outer waterresistant cover member to enclose substantially all of the container or to enclose all but the basal portion ofthe container, and to encompass the loop-like members, b) forming one or more apertures through the cover and configured so as to lie within the loop-like members, and c) forming a closure around the periphery ofthe apertu res whereby the water-resistant properties of the cover are substantially maintained.

3. A container or method as claimed in either of claims 1 or2whereinthecontainercontainsaparti- culate fertiliser.

4. A container or method as claimed in eitherof the preceding claims wherein the container is made from woven polypropylene or polyethylene fibres.

5. Acontainer or method as claimed in any one of the preceding claims wherein the lifting loops are formed integrally with the walls ofthe container by extending opposed side walls of the container and joining those extensions together above the body of the container to form loops standing proud above the upper face ofthe container.

6. A container or method as claimed in any one of the preceding claims in which the outer cover is provided as a single component which extends partially over the basal face ofthe container and which is shrunkontothefilled container so thattheouter cover forms a partial cover to the base ofthe container.

7. A container or method as claimed in any of the preceding claims wherein the outer cover is formed as two components, a basal component encasing the base ofthe container and an uppercomponent encasing the upper portion of the container and extending upwardly to enclose the lifting loops, so as to provide an outer cover which totally encases the container.

8. A container or method as claimed in any one of the preceding claims wherein the outer cover is made from a heat sealable material.

9. A method as claimed in any one ofthe preceding claims 2 to 8 wherein the apertures through the outer cover atthe lifting loops are formed by bring- ing togetherthe walls of the cover lying to each side of the plane of the loop, cutting outthe material from the outercoverwalls within the confines of the loop, and sealing together the edges of the material aroundthecutawayportionstoformaseal around the aperture.

10. A container or method as claimed in anyone ofthe preceding claims wherein the container has an inner liner, which may be a single sheet material ora composite or laminated material.

11. Amethod as claimed in anyone of claims 2to 10 wherein the outer cover is a single member having a closed lower end into which a container is fitted base first, the open end of the outer cover then being sealed or otherwise closed above the lifting loopsto form a water-resistant envelope around the container.

12. A method as claimed in anyone of claims 2to 11 wherein the apertures in the outer cover are formed by bringing together the opposed walls of the cover at the location ofthe aperture by a heat sealer/cutter bar having the desired shape so asto form to form the apertures and seal the severed edges ofthe wall material in asingleoperation.

13. Acontainerormethod as ciaimed in any one of the preceding claims wherein the container is provided with means whereby it can be filled after the cover is fitted and this means comprises a second aperture through the outer cover through which an aperture orfilling spout provided on the container can be accessed from the filling machine.

14. A container as claimed in claim 13which does not contain any particulate material.

15. A method as claimed in claim 13 wherein the container is filled afterthe outer cover has been formed on the container.

16. Acontainerormethod as claimed in claim 13 wherein the second aperture is orientated axially on the cover.

17. Acontainerormethod as claimed in anyone of the preceding claims wherein the outer cover is provided with meansforventing airtrapped between the container and the outer cover during filling ofthe container.

18. A container or method as claimed in any one ofthe preceding claims wherein the container is mounted upon a pallet or other load-bearing platform to permit base lifting of the container.

19. A container or method as claimed in either of claims 1 or 2 respectively, substantially as hereinbefore described with respect to and as shown in the accompanying drawings.

20. Acontainerwhen made bythe method of claim 2.