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(11) | EP 0 179 624 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A container of flexible material |
| (57) A container (17) of flexible material comprises an outer panel (16) which overlaps
and is welded to an adjacent panel in side welds (20, 21) and in a transverse seam
(14). The panel (16) is provided with a transverse row of serrations (13) providing
the container (17) with a tamper evident closure. |
[0001] This invention relates to a container of flexible material and particularly but not exclusively to a container of synthetic plastics film material.
[0002] It is known to provide bags of synthetic plastics film material wherein the bags are each provided with a capture flap. Generally, such bags are manufactured from a sheet which is folded to provide two layers, one of which is of greater dimension than the other in a direction transversely of the fold thereby providing a flap. The flap is folded so as to overlie a portion of the adjacent layer and opposite spaced parallel side margins of the layers and the flap are welded one to another to provide side seams.
[0003] An advantage of capture flap type bags is that they provide an inner wall inside the flap which assists in retaining contents in a bag.
[0005] It is desirable, therefore, to provide a container having the advantage of a capture flap bag and which also which is provided with a tamper evident closure.
[0006] A well known method of providing a container of flexible material with a tamper evident closure is to perforate the material with a row of serrations. In EP 0 134 130 (Sanders) for example there is disclosed a container of flexible material having an opening location which may be in the form of a row of serrations. Opening of the container is effected by severing the portions of the material bridging adjacent serrations. Once the material has been severed, it is difficult to re-seal the material without providing indication that the container has previously been opened.
[0007] The container disclosed in EP 0 134 130 is not a capture flap container and is not provided with an inner wall which assists in retaining contents in the container.
[0008] The invention overcomes the problem by providing a container of flexible material which is characterised in that an outer panel of the container is secured to an inner panel of the container in a seal extending substantially at right angles to seams of the container and a line of weakening is provided in the material of the outer panel, the line extending in spaced substantially parallel relationship with the seal whereby the container is openable by fracturing the material at the line of weakening.
[0009] Following is a description, by way of example only and with reference to the accompanying drawings, of one method of carrying the invention into effect.
[0010] In the drawings:-
Figure 1 is a diagrammatic cross section of one embodiment of a container in accordance with the present invention,
Figure 2 is a view in the direction of arrow 'A' of Figure 1,
Figure 3 is a diagrammatic cross section of the container shown in Figures 1 and 2 when in an open condition,
Figures 4 and 5 are diagrammatic representations of stages in the manufacture of the embodiment of the container shown in Figures 1 and 2,
Figures 6 and 7 are diagrammatic representations of stages in the manufacture of another embodiment of a container in accordance with the present invention,
Figures 8 and 9 are diagrammatic representations of stages in the manufacture of another embodiment of a container in accordance with the present invention,
Figures 10 to 12 are diagrammatic representations of stages in the manufacture of another embodiment of a container in accordance with the present invention,
Figure 13 is a view similar to Figure 12 of another embodiment of a container in accordance with the present invention,
Figures 14 to 16 are diagrammatic representations of stages in the manufacture of another embodiment of a container in accordance.with the present invention,
Figures 17 to 19 are diagrammatic representations of stages in the manufacture of another embodiment of a container in accordance with the present invention,
Figure 20 is a diagrammatic representation of another embodiment of a container in accordance with the present invention,
Figure 21 is a diagrammatic representation of another embodiment of a container in accordance with the present invention,
Figure 22 is a perspective view of another embodiment of a container in accordance with the present invention, the container being shown being loaded with contents,
Figure 23 is a view similar to Figure 22 showing the container having been closed after contents have been inserted therein,
Figure 24 is a view similar to Figures 22 and 23 showing the container being opened, and
Figure 25 is a view similar to Figures 22, 23 and 24 showing contents of the container being removed. through an opening of the container.
[0011] Referring now to Figures 1 to 5 of the drawings, there is shown a web 10 of plastics film material comprising spaced parallel longitudinal marginal edge portions 11, 12. The web 10 is provided with a row of serrations 13 extending longitudinally of the web and adjacent the marginal edge portion 12.
[0012] The web 10 is fed through a vertical form/fill/seal packaging machine (not shown) wherein the'web is formed into a vertically extending tubular configuration such that the marginal edge portion 12 overlaps and is welded to the adjacent portion of the folded web 10 in a lap seal 14. The configuration is such that there is an inner panel 15 extending between the marginal edge portion 11 and the lap seal 14 and an outer panel 16 overlapping the inner panel 15. The tubular configuration is welded in a transverse weld (not shown) and an article is, or a batch of articles are, inserted in the tubular configuration and retained therein by the transverse weld. The tubular configuration is then advanced longitudinally and is welded in a second weld (not shown), the material being simultaneously severed mid-way through the second weld and transversely of the tubular configuration to provide a completed container 17. The process is then repeated to provide further formed, filled and sealed containers 17. The effect of so sealing the tubular configuration is to provide each container 17 when turned through 90° from a longitudinal axis of the tubular configuration, with a lower fold 18, an upper fold 19 and spaced parallel side welds 20, 21.
[0013] In each completed container 17, an outer panel 16 provides a capture flap which is sealed to an adjacent inner panel 15 adjacent an opening thereof by a transversely extending seal 14. The dimension of the inner panel 15 in a direction away from the lower fold 18 is such that the upper marginal edge of the inner panel 15 curls inwardly of the upper fold 19, asshown at 19a.
[0014] Each container 17 is opened by fracturing the material of the container bridging adjacent serrations 13 and reverse folding the outer panel 16, as shown in Figure 3,and is reclosed by folding the outer panel 16 so that the panel 16 returns to the position shown in Figure 2.
[0015] Since the serrations 13 cannot be reformed, the arrangement provides a container 17 having a tamper evident closure.
[0016] The inner curl 19a of the panel 15 extending inwardly of the upper fold 19 restricts tendency for contents to slide through a gap betwen the inner and outer panels 15, 16 when the container is closed and irnerted.
[0017] This restriction is particularly advantageous if the contents are a granular substance such as sugar. The curl 19a also has the effect of closing the gap during any bulging of the container.
[0018] In order to provide each container 17 with an airtight closure, various embodiments may be incorporated.
[0019] In irst embodiment shown in Figures 6 and 7, a elable pressure sensitive contact adhesive tape 22 is applied to an upper surface of the web 10 prior or subsequent to formation of the web into the tubular configuration, the tape 22 covering and extending longitudinally of the row of serrations 13. The tape is of a material such that it is severed when the material of the web 10 is severed. In the completed containers 17, therefore, the portion of the tape 22 incorporated in each container provides a barrier to the passage of air through the serrations 13. When each container 17 is to be opened, the tape 22 is peeled from the container and the container opened in the manner described above.
[0020] A second embodiment is shown in Figures 8 and 9 and is formed by applying a strip of re-usable pressure sensitive contact adhesive or peelable heat seal lacquer 23 longitudinally of a lower surface of the web 10 prior to formation of the web 10 into the tubular configuration, the adhesive strip 23 being located inwardly of the row of serrations 13 from the marginal edge portion 12. When each container 17 is formed, the portion of the adhesive strip 23 contained in the container is located between the panels 15, 16 and adhesively unites the panels one to another and restrains passage of air between the panels. Since the adhesive 23 is re-usable, the panels 15 and 16 can be separated one from another to effect opening of the container 17 and are re-united one with another on reclosure of the container 17.
[0021] Referring now to Figures 10 and 11 of the drawings, there is shown a web 24 similar to the web 10 and comprising spaced parallel marginal edge portions 25 and 26 and a row of serrations 27 extending parallel to and adjacent the marginal edge portion 26. As the web 24 is advanced towards a vertical form/fill/seal packaging machine it is laid over a narrower web 28 comprising spaced parallel marginal edge portions 29, 30, the edge portion 30 coinciding with the edge portion 26 of the larger web 24. The narrower web 28 is of a material compa'tible with the adjacent surface of the web 24 in that the two webs weld one to another when operated on by the packaging machine to provide a lap seal 31 and transverse seams, and the web 28 is severable by the machine. Furthermore, the dimension of the web 26 in a transverse direction thereof corresponds substantially with the dimension of the panel 16 in the direction from the lower to upper folds 18, 19 of each of the containers 17.
[0022] In consequence, when the combined webs 24 and 28 are formed into containers 32, the area adjacent the marginal edge portion 30 of the web 28 is united in the lap seal 31 and the containers 32 are of substantially similar configuration to the containers 17, each portion of the web 28 contained in each container 32 corresponding to the inner panel 15 of the container 17.
[0023] If the manufacturing process requires each container to be provided with a fin seal 33 instead of a lap seal 31, the process can be carried out using the webs 24 and 28 in the manner described above.
[0024] It will be appreciated that by using the web 28 containers 32 may be manufactured on standard packaging machines without having to modify such machines to accommodate wider webs to produce containers of standard dimensions.
[0025] It will also be appreciated that containers may be provided with an opening located on a panel remote from the lap seal (or fin seal). In Figures 14 to 16 for example, a web 34 is provided with a row of serrations 35 extending longitudinally of the web. The web 34 is advanced towards a packaging machine in synchronism with a narrower web 36, similar to the web 28, the wider web 34 extending above the narrower web 36 and the narrower web 36 being located so ,as to extend transversely on either side of the row of serrations 35. The narrower web 36 comprises spaced parallel marginal edge portions 37, 38 and is united with the wider web 34 by means of a strip of a pressure sensitive contact adhesive or heat sealing lacquer 39 extending adjacent the marginal edge portion 37. When formed into containers, see Figure 16, an inner panel formed by the narrower web 36 is located on an inner surface of the container remote from a lap seal 40 of the container.
[0026] Referring to Figures 17 to 19 of the drawings, there is shown a web 41 comprising spaced parallel longitudinal marginal edge po'rtions 42, 43 and a row of serrations 44 extending longitudinally of the web, the row of serrations 44 being located nearer the edge portion 42 than the edge portion 43. The web 41 has located thereon a substantially narrower web 45 which extends longitudinally of the wider web 41, the narrow web 45 comprising spaced parallel longitudinal marginal edge portions 46, 47. The narrower web 45 is secured to an upper surface of the wider web 41 by means of welding or a strip of pressure sensitive contact adhesive 48 extending longitudinally of the narrower web 45 and adjacent the edge portion 46 thereof and located between the two webs. The adhesive strip 48 is applied to the upper surface of the wider web 41 at a location adjacent the row of serrations 44 and between the row of serrations 44 and the edge portion 42.
[0027] The combined webs 41 and 45 then are formed into bags, one of which is shown diagrammatically at 49, by folding the web longitudinally, as shown at 50, such that the edge portion 43 extends above and adjacent the edge portion 42 and subsequently welding and severing the overlapping layers. One of the welds 51 extends in spaced substantially parallel relationship to the fold 50 to provide a handle portion 52 and other welds (not shown) are provided which extend transversely of the folded web 41 at spaced locations longitudinally of the web, the welding operation in providing the transversely extending welds also effecting severance of the material in the welds thereby converting the combined webs 41, 45 into the bags 49.
[0028] The bags 49 thus are opened at an end portion remote from the fold 50 and are supported in an inverted position for filling by temporarily securing to a suppport (not shown) an extended lip 53 adjacent the edge portion 43. Subsequently, the end portion is closed by welding the layers of. the folded web 41 adjacent the lip 53 and the edge portion 42; as shown in dotted lines in Figure 19, the welding simultaneously removing the lip 53.
[0029] It will be appreciated that the portion of the row of serrations 44 incorporated in each container 49 provides the container with a tamper evident closure.
[0030] It will also be appreciated that each of the embodiments described above with reference to Figures 10 to 12; 13; 14 to 16 and 17 to 19 may be provided with the tape 22 or adhesive 23 or a peelable heat seal described above with reference to Figures 6 and 7 and 8 and 9.
[0031] Referring now to Figure 20 of the drawings, there is shown a diagrammatic representation of an embodiment of a container formed from a folded web 54 comprising a row of serrations 55 and a lap seal 56. The container is provided with an inner panel 57 formed from a narrower web located on a lower surface of the web 54, prior to formation of the container, by means of spaced parallel strips of pressure sensitive contact adhesive 58,59 located adjacent corresponding longitudinal marginal edge portions of the narrower web and on opposite sides of the row of serrations 55.
[0032] The adhesive strips 58, 59 locate the narrower web 57 during manufacture of the containers and provide barriers to passage of air into the containers through the serrations 55.' The strip 59 is a re-usable adhesive so as to provide a facility whereby the inner panel 57 can be separated from contact with an adjacent surface of the container to effect opening of the container.
[0033] In Figure 21 there is shown an embodiment of a container similar to that shown in Figure 20 except that the inner panel 60 is located on an opposite surface of the container and is united therewith in a lap seal 61. In consequence, only a single strip of pressure sensitive contact adhesive 62 is required to provide a barrier to air passing through serrations 63 comprising an opening, the adhesive 62 being re-usable.
[0034] It will be appreciated that the strip of adhesive 62 may be located substantially along a central longitudinal axis of the web from which the panel 60 is provided, thereby avoiding necessity of providing webs with strips of adhesive 62 at different locations for different configurations of container.
[0035] It will also be appreciated that the surface of each of the webs which will provide the inner panels 57,60 may be subjected to electric corona discharge so as to 'key' the surface prior to receipt thereon of the adhesive strips 58, 59 and 62. The 'keyed' surface ensures that the adhesive is not transferred to an opposite surface when a container is opened, the said opposite surface being a surface with which contents of the container may come into contact when being inserted into or issuing from the container.
[0036] Referring now to Figures 22 to 25 of the drawings, there is shown a container 64 comprising two panels 65, 66 of synthetic plastics film material welded one to another in side seams 67, 68. Also welded in the side seams are opposite marginal edge portions of a sheet 69 of synthetic plastics film material which extends between the panels 65, 66 and an upper portion 70 of which extends upwardly beyond the panels 65, 66. One of the panels 65 is provided with a row of serrations 71 extending transversely of the panel 65 and the upper portion 70 of the sheet 69 is provided with apertures 72.
[0037] The apertures 72 are provided so that the container 64 is attachable to a wicket (not shown) for supporting the container in an open condition while articles, such as slices of a sliced loaf of bread, are inserted therein, as shown in Figure 22.
[0038] Subsequently, the panels 65, 66 and the internal sheet 69 are welded one to another in an upper transversely extending weld 73. The sheet 69 is severed simultaneously with the welding operation providing the upper weld 73 whereby the upper portion 70 of the internal sheet 69 is removed from the portion of the sheet extending into the filled and sealed container 64, as shown in Figure 23.
[0039] Opening of the container 64 is effected by bursting the material of the panel 65 at the row of serrations 71, as shown in Figure' 24, and raising the internal sheet 69 to remove one or more of the articles, as shown in Figure 25.
[0040] It will be appreciated that each of the inserts 28, 36, 45, 57, 60 and 69 may be of a different material from the material forming the remainder of the container provided with each insert. Provided that the surface of each insert is compatible with an adjacent surface of the material of the corresponding container to ensure welding and severing to be effected, each insert may be provided of material which may have different properties from the remaining material of the corresponding container.
[0041] The inserts 28, 36, 45, 57, 60 and 69 may be of material of different thickness to the material forming the remainder of the container. For example, the material of the insert may be of thicker material to provide greater rigidity or may be of thinner material to reduce cost.
[0042] The inserts 28, 36,45, 57, 60 and 69 may be coloured or tinted so as to indicate location of entry and exit of articles into and from a corresponding container.
[0043] Furthermore, it will be appreciated that by selecting suitable materials whereby each of the inserts 28,36, 45, 57, 60 and 69 clings to an opposite facing wall containing the corresponding row of serrations, movement of the insert material during manufacture of a container relative to an adjacent web or sheet which is to form the container is reduced or eliminated, thereby restricting the passage of the contents of the container between the insert and the opposite facing wall.
[0044] With vertical form/fill/seal machinery provided with a bel\ transport system for advancing a web in tubular configuration, attachment of the inserts to an inner wall of the configuration, either by the adhesive 59, 62 or by the clinging effect referred to above or by intermittent spot welding one to another, ensures that relative movement of the tubular configuration and the inserts is eliminated or reduced to a minimum.
[0045] It will also be, appreciated that containers in accordance with the present invention may be manufactured from plastics film material provided with a row of serrations and having insert material located thereon, the combined materials being wound in a reel. In order to ensure balanced reel geometry, an additional web of removable material preferably would be wound in the reel in spaced relationship to the said insert material longitudinally of the reel.
1. A container (17, 32, 49, 64) of flexible material comprising an inner panel (15,
28, 36, 45, 57, 60, 69) and an outer panel (16, 24, 34, 41, 54,65) united therewith
in seams (20, 21, 67, 68) characterised in that the outer panel (16, 24, 34, 41,54,65)
is secured to the inner panel (15, 28, 36, 45,57, 60, 69) in a seal (14, 31, 33, 39,
48, 58, 61, 73) extending substantially at right angles to the seams (20,21,67,68)
and is provided with a line of weakening (13, 27, 35, 44, 55, 63, 71) extending in
spaced substantially parallel relationship with the seal (14,31,33,39,48,58,61,73)
whereby the container (17,32,49,64) is openable by fracturing the material at the
line of weakening (13,27,35,44,55,63,71).
2. A container as claimed in claim 1 characterised in that the line of weakening (13,27,35,44,55,63,71)
comprises an opening in the material.
3. A container as claimed in claim 2 characterised in that the line of weakening (13,27,35,44,55,63,71)
comprises a plurality of openings.
4. A container as claimed in any one of the preceding claims characterised in that
a barrier (22,23,58,59,62) is provided to restrain passage of gas between the panels
(15,28,36,45,57,60,69) (16,24,34,41,54,65), the barrier (22,23,58,59,62) being capable
of relinquishing the said restraint to permit opening of the container (17,32,49,64).
5. A container as claimed in claim 4 characterised in that the barrier (22,23,58,59,62)
comprises a re-usable pressure sensitive contact adhesive.
6. A container as claimed in claim 4 or claim 5 characterised in that the barrier
(22,23,59,62) is a peelable seal.
7. A container as claimed in any one of claims 4 to 6 characterised in that the barrier
(22,23,58,59,62) is located between the panels (15,28,36,45,57,60,69) (16,24,34,41,54,65).
8. A container as claimed in any one of the preceding claims characterised in that
the inner panel (15,28,36,45,57,60,69) is curved inwardly about an axis extending
substantially parallel to the seal (14,31,33,39,48,58,61,73) to provide an inner curl
(19 a) .
9. A container as claimed in any one of the preceding claims characterised in that
the inner panel (28,36,45,57,60,69) comprises an insert in the container (32,49,64),.
10. A container as claimed in any one of the preceding claims characterised in that
the insert (28,36,45,57,60,69) is of different material from the material of the outer
panel (24,34,41,54,65).