[0001] This invention relates to tamper evident bags, and in particular, to bags which are
intended for the transportation of cash or other valuables.
[0002] Various types of such security bags have previously been proposed, including seals
with security printing or special patterns of lines combined with layers of adhesive,
so that any effort to tamper with the seal can easily be detected.
[0003] For certain applications, however, it is necessary to provide a bag having a first
pocket for containing cash, such as coins, which can be closed with a security seal,
and also including a second sealable pocket which may be opened separately, for containing
banknotes or identifying documents.
[0004] Accordingly, the present invention provides a tamper evident bag including a first
pocket of plastics material with an opening having a closure flap adapted to form
a tamper evident seal and a second pocket, whose opening is adjacent to that of the
first pocket so as to be closed by the same flap, characterised in that the second
pocket has an external wall which is perforated so as to allow separate access to
the second pocket by tearing the perforations after the bag has been sealed.
[0005] Preferably, the first pocket is made by folding over one end of an elongate strip
of plastics material such as translucent or transparent polyethylene, and sealing
the opposite side edges to form a pocket, and then heat sealing further layers or
strips of polyethylene material, onto the bag in a known fashion to form the required
further pocket and closure flap.
[0006] Preferably, the tamper evident seal comprises a seal embodying layers of adhesive
and patterns of lines which are broken up when the seal is opened, as described for
example in WO 91/04199, or WO 93/16933.
[0007] Preferably, the second, or outer pocket, is made of two layers of opaque material,
so that the contents of the pocket cannot be seen through the material of the bag,
and in a preferred embodiment, each of these layers is made from co-extruded polyethylene
material, which facilitates the production of an opaque or coloured material. Alternatively
all the layers may be translucent or transparent.
[0008] One embodiment of the invention will now be described by way of example, with reference
to the accompanying drawings, in which:
Figure 1 is a plan view of a bag in accordance with the present invention, and
Figure 2 is a cross-section on the line II-II of Figure 1, with the spacing between
the layers of material exaggerated for clarity.
[0009] Referring to the drawings, it will be seen that the main body of the bag is made
from an elongate strip of plastics material, such as polyethylene 2, which is folded
over at one end 4, so that the overlapping section, 6, extends about half way along
the total length of the bag. This forms the inner end of the first pocket.
[0010] The remaining part of the first pocket is formed by a second layer, 8, of opaque
co-extruded polyethylene material, which is heat sealed, as illustrated at 10, to
the short edge of the main part 2 of the bag, i.e. the end opposite the folded end
4. The co-extrusion process facilitates the production of opaque and/or coloured layers,
if required. The other end of sheet 8 is heat sealed, as illustrated at 12, to the
opposite free end of the overlapped portion 6 of the main body, and a transverse slit
14 in the sheet 8 forms the opening to the main pocket of the bag.
[0011] A second pocket is formed by superimposing a further short length 16 of co-extruded
opaque material, whose lefthand edge, as seen in the drawings, is also heat sealed
along the line 12, whilst its righthand edge, 18, is left free, forming an opening
to the second pocket which is adjacent to the opening 14 of the main pocket. Finally,
a strip 20 including a tamper indicating seal is heat sealed by one edge, at 22, so
as to form a flap overlying both openings, as shown in Figure 2.
[0012] All the layers of the bag are then heat sealed along the opposite side edges 24 and
26, and as will be seen from the drawings, this creates a completely enclosed region
at the righthand end, bounded by the side edges and the heat seal lines 10 and 22,
which can be used to form a handle for the bag by means of an aperture 28 (not shown
in Fig. 2). This area may also be colour-coded by virtue of the co-extruded material
8. The edges of the aperture 28 are also heat sealed, and consequently, since the
end portion consists of two superimposed layers of material, and is heat sealed along
all its free edges, it provides a strongly reinforced region for the bag handle.
[0013] As will be appreciated from a consideration of Figure 2, the tamper evident closure
20 forms a seal across the openings of both pockets of the bag, when it is closed.
In order to allow documents to be removed from the second pocket, without breaking
this seal, a line of perforations 30 is provided, at the lefthand edge of the pocket
as seen in the drawings. Because the edge 18 is positioned to the left of the slit
14, the main pocket remains sealed even though the second pocket is open.
1. A tamper evident bag including a first pocket (6) of plastics material with an opening
having a closure flap (20) adapted to form a tamper evident seal and a second pocket,
whose opening is adjacent to that of the first pocket so as to be closed by the same
flap, characterised in that the second pocket has an external wall (16) which is perforated
so as to allow separate access to the second pocket by tearing the perforations (30)
after the bag has been sealed.
2. A tamper evident bag according to claim 1 in which the first pocket is made by folding
over one end of an elongate strip of plastics material and sealing the opposite side
edges (24, 26) , and also sealing further strips (8, 16) of plastics material onto
the bag to form the second pocket and the closure flap.
3. A tamper evident bag according to claim 1 in which the tamper evident seal includes
superimposed layers of adhesive and patterns of printed lines so that the patterns
are disrupted when the seal is opened.
4. A tamper evident bag according to claim 1 in which the layers of material forming
the second pocket are opaque so as to conceal its contents.
5. A tamper evident bag comprising:
a first elongate strip (2) of plastics material having less than half of its length
folded over to form a partial overlap, and having its overlapped edges (24, 26) heat-sealed
together;
a second strip (8) of plastics material of substantially the same width, which extends
over the remaining area of the first strip, the second strip being heat-sealed all
around its edges, to the side edges (24, 26) and the free ends (10, 12) of the first
strip, so as to form an enclosed first pocket;
a third strip (16) of plastics material superimposed over the second strip, and heat-sealed
to the second strip along its side edges (24, 26) and to one joined edged (12) of
the first and second strips, to form a second pocket with one open end (18);
a tamper evident sealing means (20) arranged to overlap the said open end, and an
aperture (14) in the second strip, for access to the first pocket, adjacent the said
open end (18) and beneath the sealing means (20) whereby closure of the sealing means
closes both the first and second pockets.
6. A tamper evident bag according to claim 5 in which the tamper evident sealing means
includes superimposed layers of adhesive and patterns of printed lines so that the
patterns are disrupted when the seal is opened.
7. A tamper evident bag according to claim 5 in which the second and third strips of
material are coloured so that the second pocket is opaque.
8. A tamper evident bag according to claim 5 further comprising, a line of perforations
(30) in the said third strip, in an area which is not overlapped by the sealing means,
whereby the second pocket may be opened without breaking the tamper evident seal.
9. A tamper evident bag according to claim 5 in which the tamper evident sealing means
comprises a strip which extends across the width of the bag and has one edge heat-sealed
to the bag at a position which is adjacent to but spaced from, the end remote from
the folded end, so as to form a sealed reinforced region of the bag at the said remote
end, an aperture being formed in the said region to provide a handle.