[0001] This invention relates to flexible intermediate bulk container bags such as those
used in the storage and transport of materials in granular, powder or other particulate
forms and known as "IBC's".
[0002] Such containers are generally in the form of large bags or sacks which are often
required to carry loads of half a tonne, one tonne or more, with a considerable safety
margin above their rated working load. The containers are commonly made from woven
fabric, particularly woven polyethylene or polypropylene, or of another synthetic
material. Typically such a container comprises a base, a main body structure of front
rear and side walls extending upwardly from the base and one or more lifting loops
formed from upward extensions of the side walls. Especially where protection from
moisture is required, it is not uncommon to provide such container bags with a waterproof
liner usually formed from plastics material sheeting, for example polyethylene sheeting.
[0003] When filling and discharging such IBC's having liners it is desirable to avoid the
liner and IBC becoming separated. In one proposal to this end, flaps formed from the
liner body are sewn into the lifting loop during the manufacture of the IBC. While
this securely attaches the liner to the IBC there are disadvantages in securing the
liner during IBC manufacture in that it complicates the manufacturing process, and
reduces the flexibility of the product: i.e., the liners cannot be added later at
a separate location nor can bags manufactured with a given liner easily have the liner
changed if the client changes his specification. Moreover, for recycling purposes,
it is often desirable to separate the liner and bag (they are often of different materials)
and this is not completely possible where substantial portions of the liner are securely
held within the bag loops.
[0004] The invention seeks to provide a method of securing a liner to an IBC improved in
the above respects.
[0005] According to the present invention there is provided a method of securing a liner
within an IBC which, in its broadest form, comprises taking one or more portions of
the liner separated from the content receiving portion and attaching the or each area
at or near the top of the IBC.
[0006] The attachment may be carried out by any suitable method for example gluing, heat
sealing, stitching, tying ultra-sonic welding or, preferably, by means of plastic
tags applied with a tag gun.
[0007] A common form of liner configuration is the so called "bottle" liner. This comprises
a generally rectangular sheet of plastics material heat sealed or otherwise joined
to form a flat rectangular "pillow" having one of its narrower sides open. Again by
heat sealing or other suitable means, the width of this open side is constricted to
leave a narrower opening such that when the liner is filled it resembles a bottle
in shape. The portions of the liner on either side of the bottle "neck" are separated
from the main body by a heat seal and may be cut off. However, in accordance with
the invention, these supernumerary flaps of material or "ears" are used to secure
the liner to the IBC. Being separated from the main body of the liner by a heat seal,
any damage to the ears during fixing to the bag does not disturb the integrity of
the main body portion which will therefore remain unpunctured and waterproof.
[0008] IBC's to which the method of the invention may be applied are not limited to any
particular kind. Indeed any conventional IBC requiring a liner may be provided with
one according to the method of the invention.
[0009] The invention will be described further, by way of example, with reference to the
accompanying drawings, in which:
Figure 1(a) to (d) illustrates a bottle shaped liner for use in the method of the
invention;
Figure 2 is a similar view to figure 1 of a different form of liner;
Figure 3 is a similar view to figure 1 of another form of liner;
Figure 4 is a diagrammatic view of the liner inserted into the IBC; and
Figure 5 illustrates the method of the invention with corner aperture liners.
[0010] Referring to the drawings, and in particular figure 1, a liner generally designated
10 is formed from a length of tubular plastics sheet material, e.g. tubular polyethylene,
which is laid flat and sealed at 12 to provide a generally pillow shaped object open
at its right hand edge as viewed in figure 1. Further heat seals 14 are applied so
as to define a filling neck area 16 leaving the flaps 18 or "ears" separated from
the main body 20 by the heat seals 14. Slits 22 are cut to partially separate the
ears 18 from the filling neck 16. As illustrated in figure 1, the bag is folded longitudinally
into a W shape (figure 1(b)) and the ears 18 turned down on themselves as shown in
figure 1(d). The liner bottom is also folded over on itself.
[0011] In this form the liner is inserted into an IBC 24 (figure 4) having a main body portion
26, a lifting loop 28, and a filling opening 30. The neck 16 of the liner is brought
out of the filling opening 30 as illustrated. The ears 18 are attached to one surface
of the bag body by any suitable means, but preferably by tagging using a plastic tag
and tag gun.
[0012] Thus, if the bag is lifted to a filling nozzle, either by the loop 28 or by the neck
16, the bag and liner will not become separated. Furthermore, when the filled bag
is discharged (often by cutting open the base of the IBC) the liner will not fall
out into the discharge hopper. However, if it is desired to separate the liner from
the used bag (for example for recycling) then this is easily done as it is attached
only by plastic tags which can be simply cut off.
[0013] Referring now to figure 2, and using like numerals for like parts, it can be seen
here that the ears 18 have been cut down to approximately half their original height
rather than folded as in the embodiment in figure 1. Fixing to the bag takes place
as already described above. Moreover in this case a "Z" fold is employed rather than
the "W" fold in figure 1.
[0014] Figure 3 illustrates another embodiment in which the liner 10 is folded in a "omega"
shape which results in the ears 18 both being on top of the folded liner rather than
one on top and one underneath as with the figure 1 and 2 embodiments. This is advantageous
in certain instances since it means that both of the ears can be affixed to the bag
24 from the same side so that if, for instance, the bag is laid flat on the table
or other work surface it does not need to be turned over to attach the second ear
18.
[0015] Turning now to figure 5, and using like numerals for like parts, a liner 10 has a
corner aperture or neck 16 and a diagonal seal 32 leaving a single "ear" 34. The liner
is inserted into the IBC 24 and secured at one side only by three or four plastic
tags 36. Once again the ear 34 is separated from the liner main body 20 by a seal
32 so that any damage done to the ear in the tags will not affect the integrity of
the liner contents.
[0016] In each case the liner is attached to the bag utilising a portion 18 which is separated
from the main body 20 e.g. by a heat seal line, so that any damage resulting in attachment
of the portion 18 does not affect the integrity of the main body 20. Moreover the
liner is easily attached to the completed IBC and does not need to be attached during
manufacture thereof. This enables liners to be attached to ready made IBC's to meet
user specifications at short notice, or indeed liners to be changed if user specifications
change.
1. A method of securing a liner within an IBC which comprises providing a liner separated
into a contents-receiving portion and one or more ear portions separated therefrom
and attaching the or each ear portion to the IBC at or near the top thereof.
2. A method as claimed in claim 1 in which the attachment is carried out by gluing, heat
sealing, stitching, tying, ultrasonic welding or by means of plastic tags applied
with a tag gun.
3. A method as claimed in any of claims 1 or 2 in which a generally rectangular sheet
of plastics material is provided, the sheet is heat sealed or otherwise joined to
form a flat rectangular "pillow" having one of its narrower sides open, and the width
of this open side is constricted to leave a narrower opening such that when the liner
is filled it resembles a bottle in shape.
4. A method as claimed in claim 3 in which the portions of the liner on either side of
the bottle "neck" are separated from the main body by a heat seal and comprise the
ear portions.
5. A method as claimed in claim 4 in which the liner is folded longitudinally and inserted
into the IBC, after which the neck is brought out of the IBC filling openeing and
the ear portions affixed to an adjacent area of the IBC top.
6. A method as claimed in any of claims 1 to 2 in which a generally rectangular sheet
of plastics material is provided, the sheet is heat sealed or otherwise joined to
form a flat rectangular "pillow" having one of its narrower sides open, the width
of this open side is constricted at one side only to leave a narrower opening and
a single ear portion.
7. A method as claimed in claim 6 in which the liner is inserted into the IBC and secured
in one or more places on the single ear portion to the an area at or near the IBC
top.