Reclosable pack and production method thereof

Abstract

 The present invention relates to a reclosable pack (1) comprising on the outside of the full cut-off length of said pack (1) at least one detachable strip (4) parallel to the longitudinal seal (3) intended to reclose the pack (1) once said strip (4) has been detached, said strip (4) being only sealed in the two cross seal areas (2) and/or on at least one point of the longitudinal seal area (3).

Description

Field of the invention

[0001] The present invention relates to a reclosable pack, in general to a reclosable pack for snack food and confectionery food, and in particular for crisps, as well as to a method for its production.

Background of the invention and state of the art

[0002] Many food-packs are generally made of metallized or transparent, PvDC-coated or AlOx-coated plastic films in order to provide a gas barrier, in particular a humidity barrier. In the case of large and medium-size food-packs, only part of their content is generally used immediately upon initial opening. Therefore, a reclosable pack, in particular for crisps, is a good option for keeping those crisps fresh and crispy.

[0003] General ideas to reclose a bag have been disclosed in the literature. Well-known examples for those skilled in the art are plastic zippers or pressure-sensitive tape at the top open neck of a bag. Such pressure-sensitive closing systems are immediately contaminated by powder or fat contained in food such as crisps.

[0004] Most of these known solutions are not advantageous from the cost point of view, in particular for cheap disposable food packaging such as confectionery or crisp packs, where important technological adaptations of the process equipment are not economically justified.

[0005] Herrington in US patent 4,913,560 discloses an adhesive-coated plastic tape welded on the outside of a plastic bag and protected by a brittle coating material. When manually stretched, the tape causes the brittle coating to crack and separate, exposing the adhesive. The tape is then wrapped around the neck of the bag to close it.

[0006] Burke in patent application WO 00/73162 Al discloses a reclosable bag comprising towards its closed ends a fixed elastic strip with an extensibility that is sufficient to enable it to be stretched and to make a turn around the longest dimension of the bag when filled. The elastic strip is a rubber material with reversible elastomeric behaviour and low plasticity fixed outside the bag. Such elastic strips cannot be introduced in usual VFFS/HFFS processes, requiring strips with low elongation properties.

Description of the figures

[0007] To make the understanding of the present invention easier, the appended figures show several views of bags and their reclosing methods. When considering these figures in connection with the following description, the invention and many of its advantages will be readily understood and appreciated. Figures 1 and 2 represent the first embodiment of the present invention, Figures 3, the second embodiment, Figure 4, the third embodiment, Figures 5, the fourth embodiment and figure 6 and 7, two different closing options of the fifth embodiment.

[0008] Fig.1a shows the front side of a VFFS/HFFS pack.

[0009] Fig.1b shows the backside of a VFFS/HFFS pack with two strips fixed or sealed at its ends at the outside of the pack in the cross seal areas.

[0010] Fig.1c shows the standard opening of a crisp pack by cohesive rupture of the coextrusion layers.

[0011] Fig.1d shows a pack where one of the two strips sealed in the cross seal area is detached by breaking the seal at the bottom area of the pack.

[0012] Fig.2a shows a pack where the other one of the two strips sealed in the cross seal area is detached by breaking the seal at the bottom area of the pack.

[0013] Fig.2b shows the backside of a pack with both crossed strips to create closure loops for the pack.

[0014] Fig.2c and 2d show the reclosing of the pack.

[0015] Fig.3a shows two strips sealed in the cross seal areas and in the upper zone (not covered by an anti-seal lacquer) of the longitudinal seal area of the backside of the pack.

[0016] Fig.3b shows a pack where two strips sealed in the longitudinal seal area on the backside are detached by breaking the seal in the bottom area of the pack.

[0017] Fig.3c, 3d and 3e show the reclosing of the pack by making a knot with the strips at the front side.

[0018] Fig.4a and 4b show a pack where one strip, only sealed in the bottom and top cross seal area, is detached by breaking the seal in the bottom area of the pack.

[0019] Fig.4c and 4d show the closing possibility with a single strip in the lap seal area.

[0020] Fig.5a shows a pack where two strips sealed in the cross seal area are detached by breaking the seal at the bottom area of the pack for the first strip and in the top area of the pack for the second strip.

[0021] Fig.5b shows the closing possibility by rolling the pack and diagonally overlapping both strips.

[0022] Fig.6a, 6b and 6c and Fig.7a, 7b, 7c and 7d show two different reclosing methods of a pack where one strip sealed in the two cross seal areas and only on an anchoring point in the longitudinal seal area on the backside are detached by breaking the seal in the bottom and in the top area of the pack. Two anti-seal lacquer zones are present in this embodiment. In this case, the two cross seal areas fall together with the top and bottom of the longitudinal seal (fin or lap seal).

Aims of the invention

[0023] The aim of the present invention is to disclose a reclosable pack, in particular for snacks, obtainable by a vertical and/or horizontal form fill and seal process (VFFS/HFFS) without major adaptation of the pack machinery and without a major cost increase of the final pack.

Summary of the invention

[0024] The present invention discloses a reclosable pack comprising on the outside of the full cut-off length of said pack at least one detachable strip, parallel to the longitudinal seal, intended to reclose the pack, once said strip has been detached on at least one sealing point, said strip being only sealed in the two cross seal areas.

[0025] According to a first aspect of the present invention, the detachable strip is further partly sealed, at least on one point in the longitudinal seal area of said pack.

[0026] According to a second aspect of the present invention, the detachable strip remains sealed at least on one sealing point of the pack after reclosing the pack. This is an advantage for not loosing the strip and better waste management.

[0027] In a third aspect of the present invention, the reclosable pack further comprises at least one anti-seal lacquer zone on the pack.

[0028] In an additional aspect of the present invention, the reclosable pack further comprises at least one anti-seal lacquer zone on the strip.

[0029] In another additional aspect of the present invention, the reclosable pack further comprises at least one anchoring seal point positioned on the longitudinal seal of the pack.

[0030] The present invention discloses also an alternative as far as that the detachable strip is glued instead of being sealed.

[0031] Furthermore, the present invention discloses a method for the production of a reclosable pack, characterised in that at least one detachable strip is heat-sealed or glued on the outside of said pack, exclusively in the two cross seal areas of said pack during a vertical and/or horizontal form fill and seal process.

[0032] The method further specifies that said detachable strip is partly heat-sealed or glued outside on at least one point of the longitudinal seal and/or the cross seal.

[0033] The method of the present invention further discloses that said detachable strip is glued instead of heat-sealed during a vertical and/or horizontal form fill and seal process.

[0034] Finally the present invention discloses the use of a reclosable pack of the invention for snack-food packaging, confectionery packaging and crisp packaging.

Detailed description of the invention

[0035] The reclosable packaging of the present invention can be produced on common horizontal and/or vertical form fill and seal processing machines (VFFS/HFFS) by adding to the normal packaging material at least one strip of low extensibility running in the packaging line on the outside of the packaging material. Non-restrictive examples of packaging materials and strips are films of polyolefins, polyesters, polyamides, PVC, polystyrene, their copolymers, blends or laminates in mono or multilayer combinations with heat-seal coatings, barrier coatings, paper or metallic layers. In the particular case of crisp packs, extrusion or solvent adhesive based laminates of inside printed outer transparent BOPP (bioriented polypropylene), laminated against a metallized BOPP are privileged. Particularly envisaged combinations for snack food packs are BOPP/PE; BOPP/CPP; BOPP/blownPP; PET/PP; PET/CPP; OPA/PE; paper/PE.

[0036] The strips are generally partially or completely sealed or glued on the outside of both ends of the pack in the cross directional seal area and/or along the longitudinal seal (lap or fin seal) with the rest of the packaging material on the backside of the VFFS/HFFS pack. The zones where the strips should not adhere are covered by an anti-seal lacquer. The longitudinal seal is resealed in the cross seal area representing the connection of the longitudinal seal and the cross seal.

[0037] Preferred material combinations for the strips are BOPP/PET; BOPP/PE; PET/PE; OPET or OPA with peelable/rupture hot seal coating, OPET/extrusion coated PE and PET with seal coating.

[0038] The chosen pack/strip seal combinations should of cause be appropriate and are well known by those skilled in the art. Examples are respectively BOPP/BOPP; BOPP/HS coating; PET/peel coating; PET/PE peel; PET/CPP peel, etc.

[0039] Possible seals for this kind of packaging are also well-known by those skilled in the art. Non-restrictive examples are cold and heat-seal coatings such as hot melts, PVDC coatings, acrylic coatings, latex-based cold sealing coatings, etc.

[0040] The consumer of snack packs does not always pay attention to the opening side of the pack. For that reason, the strips disclosed in the present invention are disposed in such a way that opening at the "top" or at the "bottom" of the pack is possible without loosing the possibility of reclosing. For that reason, in the present invention, all different reclosing methods of a snack pack, result in a symmetrical disposal of the strips and the different sealing points versus the "top" or the "bottom" of the pack.

[0041] In a first embodiment of the present invention, two small strips 4 are added on the outside of the packaging 1 over the complete cut-off length parallel to the machine direction. In this particular case, both strips 4 are only sealed in the cross seal areas 2 and relatively distant from the longitudinal seal area 3, as illustrated in Fig.1a and 1b respectively showing the front side and the backside of a pack 1 with two strips 4 fixed at its ends on the outside of the pack 1 in the cross seal areas 2. After the standard opening of the pack 1 by cohesive rupture, adhesive rupture or even peel of the coextrusion layers, two strips 4 are detached by breaking the seal in the bottom area of the pack while keeping them sealed and attached in the top area of the bag. In the following step, both strips are crossed (Fig. 2b) to create the possibility with two loops (Fig. 2d) to reclose the pack 1.

[0042] In a second embodiment of the present invention (Fig.3a to 3e), two strips 4 are sealed in the cross seal area 2 and in the longitudinal seal area 3 of the backside of the pack 1. In this embodiment, two strips 4 are sealed together with the longitudinal seal 3 until the middle of the pack. An anti-seal lacquer is applied between the strips 4 and the packaging 1, defining an anti-seal lacquer zone 5 to make said strip 4 detachable until the middle of the pack. Fig. 3b shows two strips 4 being detached by breaking the seal at the bottom area of the pack 1 followed by making a knot with the strips on the front side (Fig. 3d and 3e) to reclose the pack.

[0043] In a third embodiment of the present invention, only one strip 4 is sealed in both cross seal areas and nowhere else. Said strip 4 is detached by breaking the seal in the bottom area of the pack 1 (Fig. 4b) and reclosed by turning said strip 4 around the top of the pack 1.

[0044] A fourth embodiment of the present invention is represented in Fig. 5a and 5b. In this embodiment, a first strip 4 is detached in the bottom cross seal area and remains attached in the top seal area, a second strip 4 is detached in the top cross seal area and remains attached in the bottom seal area. The two detached strips represent two times the full length of the cut-off length and provide different possibilities for reclosing the bag and from which, one is represented in Fig. 5b.

[0045] A fifth embodiment of the present invention is disclosed in the figures 6a, 6b and 6c and 7a, 7b, 7c and 7d. In this embodiment, a single strip 4 is sealed along the longitudinal seal on three different points. Two sealing points are on the contact point of both cross seal areas and longitudinal seal, the third one in the middle of the pack 1 on the longitudinal seal 3. This point is called the anchoring point 6. Between the three sealing points and the pack 1, two anti-seal lacquer zones 5 are used to avoid the sealing in between said sealing points. Two different reclosing possibilities provided by this embodiment are represented in the figures 6c, 7b and 7c.

[0046] Other possibilities of reclosing the pack 1 resulting from the disclosed embodiments are of cause possible. Non restrictive examples are reclosing without detaching the strip and using said strip as a loop for the pack, etc.

[0047] An advantage of the present invention is the possibility to add one or two strips in the VFFS/HFFS packaging line without any extra adaptation of the process and with basically only the strip material as additional cost.

[0048] An further advantage of the present invention is that the standard opening, by cohesive rupture, adhesive rupture or peel of the coextrusion layers in the cross seal area of the pack, remains the same and does not change the habits of the consumer.

Legend

[0049] 

1. Pack

2. Cross seal

3. Longitudinal seal (lap or fin seal)

4. Detachable strip

5. Anti-seal lacquer zones

6. Anchoring seal point

Claims

1. Reclosable pack (1) comprising on the outside of the full cut-off length of said pack (1) at least one detachable strip (4), parallel to the longitudinal seal (3), intended to reclose the pack (1), once said strip (4) has been detached on at least one sealing point, said strip (4) being only sealed in the two cross seal areas (2).

2. Reclosable pack according to Claim 1, characterised in that the detachable strip (4) is further partly sealed, at least on one point in the longitudinal seal area (3) of said pack (1).

3. Reclosable pack according to Claim 1, characterised in that the detachable strip (4) remains sealed at least on one sealing point of the pack (1) after reclosing the pack.

4. Reclosable pack (1) according to Claim 1, further comprising at least one anti-seal lacquer zone (5) on the pack (1).

5. Reclosable pack (1) according to Claim 1, further comprising at least one anti-seal lacquer zone (5) on the strip (4).

6. Reclosable pack (1) according to Claim 1, comprising two anti-seal lacquer zones (5) and at least one anchoring seal point (6) positioned on the longitudinal seal (3) of the pack (1).

7. Reclosable pack (1) according to Claim 1, characterised in that the detachable strip (4) is glued instead of being sealed.

8. Reclosable pack according to Claim 1, characterised in that said pack (1) is a crisp or a confectionery packaging.

9. Method for the production of a reclosable pack (1), characterised in that at least one detachable strip (4) is heat-sealed or glued on the outside of said pack (1) , exclusively in the two cross seal areas (2) of said pack (1) during a vertical and/or horizontal form fill and seal process.

10. Method for the production of a reclosable pack (1) according to claim 9, characterised in that said detachable strip (4) is partly heat-sealed or glued outside on at least one point of the longitudinal seal (3) and/or the cross seal (2).

11. Method for the production of a reclosable pack (1) according to Claim 9, characterised in that said detachable strip (4) is glued instead of heat-sealed during a vertical and/or horizontal form fill and seal process.

12. Use of the pack according to Claim 1 for snack-food packaging.

13. Use of the pack according to Claim 1 for crisp and confectionery packaging.

Drawing