GB2194215A - Flexible bulk container - Google Patents

Abstract

A flexible bulk container (1) comprises a body portion having eight seams (15) spaced therearound, the legs of lifting loops (11) being stitched to the seams. The seams (15) may be either "real" seams connecting two panels (2,3) or may be "false" seams ie pleats formed in a single panel. In one embodiment (Fig. 1) the container is formed from eight separate panels and is generally square with the loops (11) extending across the comers, alternatively the container may be generally cylindrical. <IMAGE>

Description

SPECIFICATION Flexible bulk containers This invention relates to flexible bulk containers.

Flexible bulk containers may be used for storage and transport of materials in granular, powder and other particulate form, such as chemicals, foodstuffs, cement and so forth.

The containers are generally in the form of large bags or sacks. They are often required to carry loads of up to one tonne or more, and there should desirably be a considerable safety margin above this working load. The containers are frequently made from woven fabric, for example woven polypropylene or any other suitable synthetic or non-synthetic material.

To avoid the use of pallets, slings or the like when lifting a flexible bulk container, flexible bulk containers are generally provided with lifting means such as loops of high strength webbing stitched to the side of the container.

The points of attachment of the lifting loops are of course regions of high stress concentration, and failure of or damage to the stitching for the loops or the bag material itself, may occur. This may be a particular problem if a container is subjected to rough treatment such as intermittent lifting movements which can result in high transient stresses.

In the prior art various methods have been proposed for attaching the lifting loops securely to the bag material. In one known arrangement for example the bag material may be reinforced in the regions where the ends of the loops are attached. Such reinforcement may be achieved by the use of additional and/or stronger warp threads. However this adds to the cost of the fabric. In another known arrangement, at the four corners of a bag the ends of a lifting loop are stitched into the seam between two side panels or alternatively by stitching the ends into a flange formed by making a fold in a continuous piece of bag material. However these arrangements have the disadvantage that both free ends or legs of a lifting loop are attached to the bag material at a single location, thus concentrating the stress at such location.Furthermore the loop tends to remain closed, thus restricting access by, e.g., the tines of a fork lift truck.

Viewed from one broad aspect there is herein disclosed a flexible bulk container comprising a base, a tubular body portion having eight seams spaced around said body portion and extending from the top to the bottom thereof, and four lifting loops each having two legs, each said lifting loop being secured to a respective associated pair of said seams by stitching one leg of said loop to one seam of said pair and stitching the other leg of said loop to the other seam of said pair.

By means of this arrangement, at least in its preferred forms, the stress created is distributed over a greater area and thus the bag is less likely to break under a load.

In a preferred form the loops extend across the corners of a generally square bag.

In this specification the term "seam" is intended to cover both a "real" seam joining two edges of material, and a "false" seam formed by folding a continuous piece of bag material so as to produce a flanged portion projecting inwardly or outwardly.

The legs of the loops may be stitched into the seam or onto the seam material. In either case the same stitching may be used for both the seam and loop attachment, thus saving labour and facilitating ease of construction.

In a preferred embodiment the bag may be formed from eight separate panels stitched together to form the body portion with one leg of a lifting loop being sewn into each seam.

Alternatively the body portion may be made from a single strip of bag material folded round to make a cylinder, the ends of the strip being stitched together with one real seam. Seven false seams may then be added to the cylinder and to the seams are attached four lifting loops. In another embodiment the body portion may comprise a single piece of fabric woven in a cylindrical form. To this body portion eight false seams may be added to which four loops are attached.

Some embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 shows a flexible bulk container formed from eight side panels, Fig. 2 is a view along the line 2-2 of Fig. 1, Fig. 3 shows a flexible bulk container where the body portion is formed as a cylindrical element, and Fig. 4 is a view along line 4-4 of Fig. 3.

Referring firstly to Fig. 1, there is shown a flexible bulk container 1 the body portion of which is formed from eight separate side panels 2-9 of woven polypropylene. To form the body of the container adjacent panels are sewn together to form seams 15, extending the full height of the container. A base panel, not shown, is sewn into the bottom of the body portion while the upper opening 10 may be provided with any suitable closure. Either or both of the upper closure and the base panel may be provided with a filling/discharge spout as desired.

To the bag portion of the container are secured four lifting loops 11. Each lifting loop, which is a strip of strong fabric webbing, comprises two legs 12. Each leg of a lifting loop is stitched into a seam securing two of the panels together and extends a part of the way down the seam. The four loops provide eight legs, and one leg is stitched into each of the eight seams of the body portion.

The manner in which a leg of a lifting loop is secured to the body of the container is shown schematically in Fig. 2. The edge portions 13 of the panels 3,2 are folded away from the interior 14 of the container. The nature of the edge portions 13 will depend on the width of the panels in relation to the width of the originally woven fabric forming the panels. If the width of the woven fabric forming the panels is the same as the desired width of the panels, both edge portions will be selvedges. If the width of the fabric is greater than that desired for the panels, then one edge portion will be a fabric selvedge while the other will be a hot cut edge. Since the fabric selvedge tends to be stronger than the remainder of the fabric, it is preferred that both edge portions 13 will be fabric selvedges.If desired, either or both of the edge portions could be additionally reinforced by any suitable- known means, such as by using additonal and/or stronger warp threads. The leg 12 of a lifting loop is stitched into place between the two edge portions 13.

As will be seen from Fig. 1, the loops 11 are arranged to cross over the corners of the body portion; This is achieved by providing corner forming folds in the centre of four of the panels and then securing the legs of a loop to the seams at the two edges of the corner panels.

As an example of this first embodiment, a container may be formed from eight panels each 50 cm wide and 125 cm high. The loops are each formed from a 160 cm long strip of 28 mm wide webbing. The legs of the loop are- stitched into the seam for a length of 60 cm, that is, approximately half the height of the container, providing a 40 cm loop. The edge portions are approximately 2 cm wide and after stitching the bag size is about 90 x 90 x 125 cm.

Fig. 3 shows an alternative generally cylindrical construction which may be formed in two separate ways. The body portion of the container may be formed from either a single piece of fabric the erjds of which are joined together at a seam, or alternatively the body may be woven in a cylindrical form to begin with. The body portion is then provided with either seven or eight false seams respectively to provide a-total of eight seams 15. The legs 12 of the-lifting loops are then stitched into the seams as before.

Fig. 4 shows schematically a false seam construction. The material of the body portion is provided with an outward fold to provide a flange portion consisting of two "edge portions" 13' similar to the edge portions of the real seam shown in Fig. 2. As in the Fig. 2 construction the leg of the lifting loop is stitched between the two edge portions 13' for approximately half the height of the body portion. If desired, the seams could be reinforced by e.g. introducing an additional strip of material or by continuing the legs of the loops down the full height of the bag.

Modifications to the specific embodiments and to any broad aspects thereof referred to or suggested herein may be apparent to those skilled in the art and the disclosure hereof is intended to encompass any such modifications.

Claims (10)

1. A flexible bulk container comprising a base, a tubular body portion having eight seams spaced around said body portion and extending from the top to the bottom thereof, and four lifting loops each having two legs, each said lifting loop being secured to a respective associated pair of said seams by stitching one leg of said loop to one seam of said pair and stitching the other leg of said loop to the other seam of said pair.

2. A container as claimed in claim 1 wherein said body portion is formed from eight separate panels stitched together along seams with one leg of a lifting loop being sewn to each seam.

3. A container as claimed in claim 1 or 2 wherein said body portion is generally square and the loops extend across the corners of the container.

4. A container as claimed in claim 1 wherein said body portion is generally cylindrical.

5. A container as claimed in claim 4 wherein said body portion is formed from a single strip of bag material joined at the ends by a seam.

6. A container as claimed in claim 4 wherein said body portion is formed from a single piece of bag material woven in a cylindrical form.

7. A container as claimed in any preceding claim wherein the legs of each said loop are stitched into said respective seams.

8. A container as claimed in any of claims 1 to 6 wherein the legs of each said loop are stitched onto the material forming said respective seams.

9. A container as claimed in any preceding claim wherein said seams are provided with additional reinforcing means.

10. A flexible bulk container substantially as hereinbefore described with reference to Figs.

1 or 3, and Figs. 2 and 4 of the accompanying drawings.