GB2194770A - Bags having lifting loops - Google Patents

Abstract

A bag 10, in particular an intermediate bulk container, comprises side walls 12 and a base, the side walls 12 being formed of a length of fabric which is folded back on itself to form a pocket (16, Fig. 3) and both free ends of which are secured, for example by stitching, to the base. Within the pocket is a lifting loop 18 formed of webbing bag, access to the loop 18 being obtained through one or more cut- out portions 20 in the side walls. <IMAGE>

Description

SPECIFICATION Container bag This invention relates to container bags and in particular container bags for carrying loads in the range of half to two tonnes and known as Intermediate Bulk Containers ('lBC').

For many purposes it is desirable for an IBC to be capable of being lifted from one single point, for example from the hook of a crane, without a great deal of manipulation being required by operatives. This speeds up the handling process, particularly when loading and discharging at ports.

It has been proposed to form an IBC in which the extremities of the side walls have been turned back on themselves to form a hem through which is passed a continuous loop of webbing to form a lifting loop for the container bag. In practice it has been found that this proposal suffers from the drawback that the hem stitching tends to pull apart or "grin" when lifting loads are applied.

The invention seeks to provide an IBC which may be lifted from a single point, which has adequate strength, and which is easily constructed.

According to the present invention there is provided a container bag which comprises side walls and a base, wherein the side walls are formed from a double length of fabric folded back on itself and attached to the base, forming a pocket through which is passed a continuous loop of webbing whereby to form a lifting loop for the container bag.

Preferably, the upper edges of the side walls of the bag have one or more cut out portions being formed therein to allow access to the loop of webbing carried therein. Preferably there are four such access points.

The fabrics from which the IBC bags of the invention are formed are conventional fabrics for use in this type of container bag and may be woven from polyethylene or polypropylene tape yarns. The side walls may be made from a fabric having reinforced zones or areas of interwoven reinforcing yarn, for example as disciosed in our UK Patent No. 1591091, but it is not essential in the practice of the invention, and for reasons of economy is not preferred. Where such reinforcing areas are provided, these may be as described in that patent and may be formed of interwoven threads of a higher tensile strength reinforcing yarns such as polyamide, polyester or twisted or fibrillated polypropylene. The bag base may or may not be provided with such reinforcing areas.

The webbing which forms the lifting loop may be a woven webbing of synthetic yarns, for example of the type used for car seat belts and IBC lifting loops or may be a rope, sling or hawser of suitable strength.

The IBC body can be made in a variety of ways. For example, it can be made from a circular woven fabric in which case there will be no side seams, the tubular fabric will be folded back on itself and the base will be stitched to the free edges of tubular body in the normal manner. Alternatively, it may be made from a fuli width fabric in which one side seam will be necessary; a half width fabric in which case two side seams will be necessary; or a quarter width fabric in which case there will be four side seams, one at each corner.

A particular advantage of the construction of the invention, in addition to the fact the problem of 'grinning' hem seams is eliminated, is that manufacture is simpler and cheaper.

This is because no hem seam is required, stitching the base to the side walls, necessary in any event, replaces this step.

This invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic perspective view of an IBC in accordance with the invention; Figure 2 is a similar view to figure 1 with the IBC being lifted at two access points; and Figure 3 illustrates the construction of an IBC of the invention.

Referring to the drawings, it can be seen from figure 3 that an IBC generally designated 10 comprises side walls 12 and base 14. The IBC may be constructed according to conventional practice in this field e.g. from woven polyethylene or polypropylene fabric. The side walls 12 are formed of a double length of fabric which is folded back on itself to form a pocket 16 and secured by sewing where indicated by arrow A to the fabric of the IBC base 14. Within the pocket 16 is a continuous length of webbing 18. As can be seen from figure 1 the pocket 16 extends substantially completely around the side walls 12 and has one or more cut out portions 20 to give access to the webbing 18.

It will be appreciated that while the webbing 18 is described as being a continuous loop, this loop may be formed either previously or in situ by stitching or otherwise drawing together the ends of a single length of webbing to form a continuous loop.

Figure 1 illustrates a filled IBC constructed and described with reference to figure 1, being lifted from a single point, in this case the hook of a crane 22. The bag is filled with material and the webbing 18 pulled out from the cut away portion 20 and placed on the hook 22. This causes the top of the bag to gather up as illustrated in figures 1 and 2 thus closing the top of the IBC. Thus, in IBCs constructed in this manner, nq separate top need be provided.

The IBC of the invention may be made as follows. A base 14 is provided, e.g. of woven polypropylene tape fabric 90 cm square. Fabric to form the side walls is also provided and can be, e.g. a circular woven fabric (with no side seams) or a 3.60 m (4 x 90 cm) wide length of flat woven fabric. In each case the fabric is of a length twice the height of the first IBC and is folded back on itself. The two free edges are attached to each other and the base 14, e.g. by stitching as shown at arrow A. The base 14 is attached, and the pocket 16 formed, in one stitching step.

The IBC is now ready for use and may be filled in the conventional manner. When it is desired to lift the filled IBC 10 the webbing 18 is drawn through one (figure 4) or more (figure 5) of the access points 20 and may be, as illustrated, attached to the hook 22 of a crane. The advantage of having four access points 20 is that lifting by a single point, e.g.

hook 22 can be achieved on one or two portions of the webbing 18; and if webbing is drawn from all four access points 20 the IBC can also be lifted by a fork-lift truck in a similar manner to conventional IBCs.

In a particular example a bag was constructed from a twill woven polypropylene fabric. The fabric sides were 160 cm in height formed from 3.2 m lengths, and the base 90 cm square. Heavy duty 'type 400' blue webbing was threaded within the pocket. On testing to destruction the webbing broke at a force of 11 tonnes the fabric portion remaining intact. This is well in excess of the 5 to 1 breakage to rated load ratio generally accepted in the IBC field.

Claims (8)

1. A container bag which comprises side walls and a base wherein the side walls are formed from a double length of fabric folded back on itself and attached to the base forming a pocket through which is passed a consinuous loop of webbing whereby to form a lifting loop for the container bag.

2. A bag as claimed in claim 1 in which the upper edges of the side walls have one or more cut out portions formed therein to allow access to the loop of webbing carried therein.

3. A bag as claimed in claim 2 in which there are four such access points.

4. A bag as claimed in any of claims 1 to 3 in which the webbing which forms the lifting loops may be a woven webbing of synthetic yarns, a rope, sling, or hawser of suitable strength.

5. A bag as claimed in claim 4 in which the webbing is woven webbing of the type used for car seat belts.

6. A bag as claimed in any of claims 1 to 5 in which the body is made of a circular woven fabric folded back on itself having a base stitched to the free edges of the tubular body.

7. A bag as claimed in any of claims 1 to 5 in which the body is made from a flat woven fabric with one, two or four side seams according to the fabric width.

8. An intermediate container bag substantially as herein before described with reference to and as illustrated in the accompanying drawings.