WO2007059426A2

WO2007059426A2 - Flexible bag with peelable seal assembly and method of making

Info

Publication number: WO2007059426A2
Application number: PCT/US2006/060765
Authority: WO
Inventors: David C. Ours
Original assignee: Kellogg Company
Priority date: 2005-11-10
Filing date: 2006-11-10
Publication date: 2007-05-24
Also published as: US20070104398A1; WO2007059426A3

Abstract

A seal assembly is disposed in a seal of a flexible bag. The seal assembly includes a first tab, a second tab, a middle layer of peelable adhesive sandwiched between the first tab and. the second tab, a first outside layer of adhesive that adheres to the first side of the bag, and a second outside layer of adhesive that is compatible with the second side of the bag such that second outside layer is heat sealed to the liner. The first tab and the second tab are easily grasped and may be pulled in opposite directions to break the middle layer of peelable adhesive. The middle layer is heat resistant such that the first tab and the second tab do not melt together during the formation of the seal.

Description

FLEXIBLE BAG WITH PEELABLE SEAL ASSEMBLY AND

METHOD OF MAKING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States Provisional

Patent Application Serial No. 60/735,452 for a FLEXIBLE BAG WITH PEELABLE SEAL ASSEMBLY AND METHOD OF MAKING, filed on November 10, 2005, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0002] A container, particularly a flexible bag with a peelable seal assembly and a method of making the same as disclosed herein.

2. Description of the Prior Art

[0003] Traditionally, containers and more particularly flexible bags are formed from a liner with a first side and a second side folded over the first side. The sides of the bag are heat sealed together to create a seal to enclose and seal contents within the bag. Such flexible bags are used for storing contents for a variety of goods such as for example food products and more specifically ready to eat breakfast cereals packages for crackers, cookies, candies, baking goods etc. The user pulls on the sides along the seal to break the seal and to access the contents of the bag. Generally the seals of the bag are difficult to break and the seals may have more integrity than the sides of the bag thereby requiring the user to tear the sides of the bag to access the contents of the bag.

[0004] It is known in the art to coextrude a peelable adhesive with the liner such that, when the second side is folded over the first side, the peelable adhesive faces itself. Therefore, when the seals are formed, the peelable adhesive of the first side adheres to the peelable adhesive of the second side. The peelable adhesive reduces the effort required to open the bag along the seals. The thickness of the peelable adhesive has an affect on the effort required to break the seal. However, the coextrusioxi of the peelable adhesive with the liner is difficult to control thereby making it difficult to consistently create bags with the same low opening effort. Additionally, the heat sealing process varies and it can be difficult to create identical seals on consecutive bags. In other words, it is difficult to maintain low tolerances in the process of heat sealing and the seals created by the process may have varying opening efforts. Therefore, the manufacturer of the bag must err on the side of higher opening efforts to eliminate the possibility of inadvertent openings along the seals.

[0005] In addition, the sides of the liner are thin and flexible and are therefore difficult to grasp to tear the seals. In addition, after the seal has been broken, the thin and flexible bag is wrinkled in the area of the seal and contents of the bag are trapped in the wrinkles when the contents of the bag are poured out of the bag. Therefore, as the contents of the bag are poured out of the bag the contents may get caught in the wrinkles thereby making it difficult to neatly pour the contents out of the bag. Additionally, if contents remain in the bag after the seal has been broken, the bag must be folded or a clip must be clipped onto the bag along the seal to keep the contents of the bag sealed within the bag.

[0006] It is desirable to manufacture a container, such as for example a flexible bag that is heat sealed together along a seal and is easily opened along the seal. Likewise, it is desirable to manufacture a bag that is easily grasped to pull the bag open along the seal and a method of making the same. It is also desirable to manufacture a flexible bag that does not have wrinkles along the seal to allow the contents of the bag to be neatly poured from the bag. It is also desirable to manufacture a bag that has a predefined pour spout that facilitates to pouring of the contents from the bag. Additionally, it is desirable to manufacture a bag that can be resealed along the seal to store the contents for later use. SUMMARY OF THE INVENTION AND ADVANTAGES

[0007] The current invention is a container and in the preferred embodiment a flexible bag with a seal assembly. The bag includes a first side and a second side folded over the first side. The sides are heat sealed together along seals. The seal assembly is disposed in the seal and includes a first tab, a second tab, a middle layer of peeϊable adhesive sandwiched between the first tab and the second tab, a first outside layer of adhesive that more securely adheres or more permanently adheresto the first side of the bag, and a second outside layer of adhesive that is compatible with the second side of the bag such that second outside layer is heat sealed to the liner and as with the first outside layer of adhesive to more securely adhere the second tab to the liner. The first tab and the second tab are easily grasped and may be pulled in opposite directions to break the middle layer of peelable adhesive. The middle layer is heat resistant such that the first tab and the second tab do not melt together during the formation of the seal. A resealable peelable adhesive may also be disposed between the first tab and the second tab. The tabs may also be brightly colored or printed upon.

[0008] Accordingly, the tabs are easily grasped and the thickness of the middle layer of peelable adhesive may be easily controlled such that variation in the effort to open various bags is eliminated and the effort required to peel the tabs apart may be controlled at a low effort. Likewise, the bright color or printing on the tabs alerts the user to the easily opened area. Also, the tabs reinforce the flexible liner and act as a pour spout when the contents of the bag are poured out of the bag. Additionally, the resealable peelable adhesive allows the user to reseal the bag along the seal to preserve the freshness of the contents of the bag.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Other advantages of the present invention will be readily appreciated, as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0010] Figure 1 is a perspective view of a flexible bag with a seal assembly;

[0011] Figure 2a is a front view of the flexible bag with a seal assembly wherein the seal assembly extends across an entire length of a seal;

[0012] Figure 2b is a front view of the flexible bag with the seal assembly wherein the seal assembly extends across a portion of the seal;

[0013] Figure 3a is a cross-sectional view of the bag wherein the liner of the bag includes a first layer and a second layer;

[0014] Figure 3b is a cross-sectional view of the bag wherein the liner of the bag has a single layer;

[00151 Figure 3c is a cross-sectional view of the bag wherein the seal assembly includes a re-sealable peelable adhesive;

[0016] Figure 3d is a cross-sectional view of the bag wherein the seal assembly includes a snap fastener; and

[0017] Figure 4 is a perspective view of a bagger assembly.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, a flexible bag 20 with a peelable seal assembly 22 is shown.

[0019] The bag 20 is formed from a liner 24 which includes a first layer

26 and a second layer 28 coextruded with the first layer 26 (See Figures 1 and 3a). The first layer 26 is preferably high density polyethylene. The second layer 28 is a peelable adhesive, and is more preferably low density polyethylene with polybutylene. It will be understood by those of ordinary skill in the art that a peelable adhesive is an adhesive that has less adhesive strength allowing it to be peeled apart or opened. An example of a peelable adhesive is the use of an adhesive layer that has an additive mixed into the adhesive layer to lower the adhesive strength. Those of ordinary skill in the art commonly refer to this additive as a containment. The liner 24 is folded to define a first side 30 and a second side 32 such that the second layer 28 of the liner 24 faces itself and the first layer 26 of the liner 24 faces outwardly. The first side 30 and the second side 32 of the bag 20 are heat sealed together along a top seal 34, a bottom seal 36 (see Figure 2a), and a side seal 38. When heat is applied to create the seals 34, 36, 38, the second layer 28 of the first side 30 and the second layer 28 of the second side 32 melt and adhere to one another to create the seals 34, 36, 38 upon cooling. Contents may be added to the bag 20 prior to the formation of any of the seals 34, 36, 38. The contents may be any products such as for example, food items like cookies, crackers, candy, baking goods, etc. One particular use of the present invention is for packaging ready-to-eat breakfast cereal.

[0020] The seal assembly 22 is disposed between the first side 30 and the second side 32 of the bag 20 and is more specifically sealed along the top seal 34, (see Figures I₃ 2a and 3a).

[0021] The peelable seal assembly 22 includes a first tab 40, a second tab

42 facing the first tab 40, a middle layer 44 sandwiched between the first tab 40 and the second tab 42, a first outside layer 46 disposed on the first tab 40 opposite the middle layer 44, and a second outside layer 48 disposed on the second tab 42 opposite the middle layer 44. In the disclosed embodiment, the middle layer 44 extends along an entire length of the first tab 40 and the second tab 42, but it will be appreciated by those of ordinary skill in the art that the middle layer 44 could be shorter than the tabs 40 and 42 or spaced at intervals along the lentgh of the tabs 40 and 42.. The first tab 40 and the second tab 42 are wider than the middle layer 44 such that the first tab 40 presents a first extension 70 extending beyond the middle layer 44 and the second tab 42 presents a second extension 72 extending beyond the middle layer 44.

[0022] In the disclosed embodiment, the first tab 40 and the second tab 42 are made of the same material and the material may be for example, polyethylene, polypropylene, or polyester. The middle layer 44 is a peelable adhesive that is preferably a resin blend. More specifically, the resin blend may include Surlyn^® which is manufactured by DuPont. Alternatively, the resin blend may include low density polyethylene or other materials designed to achieve the results intended by the present invention. The middle layer 44 is heat resistant such that the middle layer 44 does not allow the tabs 40, 42 to weld together during the application of heat for forming the top seal 34. The first outside layer 46 is a peelable adhesive that more permanently adheres to the second layer 28 of the liner 24 when applied to the second layer 28. Preferably the first outside layer 46 is a vinyl based adhesive. The second outside layer 48 is an adhesive that is compatible with the second layer 28 of the liner 24 to more permanently seal to the liner 24 during the formation of the top seal 34. The second outside layer 48 is preferably low density polyethylene.

[0023] When the seal assembly 22 is heat sealed into the top seal 34, the first outside layer 46, the second outside layer 48, the first tab 40, and the second tab 42 may melt to adhere to the liner 24. However, the middle layer 44 extends between the first tab 40 and the second tab 42 and because the middle layer 44 is heat resistant, the first tab 40 and the second tab 42 do not adhere to each other.

[0024] The user grasps the first extension 70 of the first tab 40 and the second extension 72 of the second tab 42 and pulls the tabs 40, 42 in opposite directions to separate the tabs 40, 42. More specifically, when the user pulls the tabs 40, 42 in opposite directions, the integrity of the middle layer 44 is compromised and the tabs 40, 42 separate. The first tab 40 and the second tab 42 may be brightly colored or may be printed upon such that it is evident that the first tab 40 and the second tab 42 may be grasped and pulled apart to access the contents of the bag 20.

[0025] The bonding strength of the middle layer 44 between the first tab

40 and the second tab 42 is easily controlled and is not affected by the heat sealing process such that the effort to separate the tabs 40, 42 and therefore the effort to open the bag 20 is consistent. Additionally, in the diclosed embodiment, the tabs 40, 42 are stiffer than the liner 24 and reinforce the liner 24 such that, after the bag 20 has been opened along the top seal 34, the tabs 40, 42 act as a pour spout and such that the contents of the bag 20 do not become lodged in wrinkles in the liner 24 as the contents are poured from the bag 20.

[0026] As shown in Figure 2a, the seal assembly 22 may be disposed along an entire length of the top seal 34. Alternatively, as shown in Figure 2b, the seal assembly 22 may be disposed along a portion of the top seal 34. If the seal assembly 22 is disposed along a portion of the top seal 24, after the user has separated the tabs 40, 42, the user continues to pull the tabs 40, 42 in opposite directions such that the second layer 28 of the liner 24 easily separates from itself along the top seal 34.

[0027] Additionally, as seen in Figure 3 c, a re-sealable peelable adhesive

66 may be disposed between the first tab layer 40 and the second tab layer 42. Preferably, the resealable peelable adhesive 66 is disposed on the seal assembly 22 extending along the entire length of the top seal 34 such that the seal assembly 22 may be resealed along the entire length of the top seal 34 to preserve the freshness of the contents of the bag 20. Preferably, the resealable peelable adhesive is a water and solvent based adhesive.

[0028] Additionally, as seen in Figure 3d, an elongated snap fastener 68 may be disposed between the first outside layer 46 and the second outside layer 48 of the seal assembly 22. The snap fastener 68 includes an elongated male portion and a complimentary elongated female portion wherein the female portion receives and engages the male portion to seal the female portion and the male portion together.

[0029] Alternatively, as shown in Figure 3b, the liner 24 may be a single layer 50 that is preferably high density polyethylene. In such an embodiment, the first outside layer 46 of the seal assembly 22 is a peelable adhesive that more permanently adheres to the single layer 50 of the liner 24 when applied to the single layer 50. Likewise, the second outside layer 48 of the seal assembly 22 is an adhesive that is compatible with the single layer 50 of the liner 24 to more permanently seal to the single layer 50 during the formation of the top seal 34. In such an embodiment, the single layer 50 would be heat sealed to itself along the top seal 34 and the bag 20 would only be opened along the seal assembly 22.

[0030] As shown in Figure 4, the bag 20 is formed on a bagger assembly

52. The bagger assembly 52 includes a hackstand 54, a labeler 56 disposed on the hackstand 54, a filler tube 58 that is generally cylindrically shaped and extends generally vertically, vertical heat seal jaws 60 extending along the filler tube 58, and horizontal heat seal jaws 62 are disposed below the filler tube 58. If the liner 24 includes the first layer 26 and the second layer 28, the liner 24 is oriented flatly along the hackstand 54 with the second layer 28 of the liner 24 facing upwardly away from the hackstand 54.

[0031] The method of forming the bag 20 includes continuously feeding the liner 24 along the hackstand 54 to the filler tube 58. The liner 24 is fed along the hackstand 54 below the labeler 56.

[0032] The method further includes facing the first outside layer 46 of the seal assembly 22 toward the liner 24 on the hackstand 54 and adhering the first outside layer 46 to the liner 24. More specifically, the labeler 56 orientates the seal assembly 22 such that the first outside layer 46 faces the liner 24. The labeler 56 also dispenses the seal assembly 22 onto the liner 24 such that the first outside layer 46 adheres to the liner 24.

[0033] The method further includes continuously feeding the liner 24 around the filler tube 58 and overlapping opposite ends 64 of the liner 24 between the vertical heat seal jaws 60. As the liner 24 is fed from the hackstand 54 to the filler tube 58 the liner 24 conforms to the cylindrical shape of the filler tube 58 and the opposite ends 64 of the liner 24 are overlapped. If the liner 24 includes the first layer 26 and the second layer 28, the liner 24 is orientated such that the second layer 28 faces inwardly toward the cylinder and the second layer 28 is facing itself along the opposite ends 64 of the liner 24.

[0034] The method further includes forming the side seal 38 of the bag 20 by closing the vertical heat seal jaws 60 to seal the opposite ends 64 of the liner 24 together.

[0035] The method further includes forming the top seal 34 and the bottom seal 36 of consecutive bags 20 by closing the horizontal heat seal jaws 62 to seal the liner 24 together and cutting the consecutive bags 20 apart between the seals 34, 36.

[0036] The method further includes feeding the contents of the bag 20 through the filler tube 58 to fill the contents into the bag 20.

[0037] The method further includes timing the step of adhering the first outside layer 46 of the seal assembly 22 to the liner 24 such that the seal assembly 22 is adhered to liner 24 in register with the horizontal seal jaws 62 such that the seal assembly 22 is disposed between the horizontal seal jaws 62 when the liner 24 is advanced and the seal jaws 62 are closed. More specifically, the bagger includes an end coder that records the length of liner 24 that has passed through bagger and the labeler 56 communicates mechanically or electrically with the end coder to adhere the seal assembly 22 in register with the seal jaws 62.

[0038] The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described.

Claims

CLAIMSWhat is claimed is:

1. A container comprising: a body portion having an inner wall defining an interior cavity and first and second opposed ends; a seal assembly mounted within one of said opposed ends, said seal assembly having opposed first and second tabs with each of said tabs having inner and outer sides; a first adhesive sandwiched between said first and second tabs engaging said inner sides of said first and second tabs, said first adhesive is a peelable heat resistant adhesive to prevent said first and second tabs from melting together during formation of said container and to allow for easy opening of said container; a second adhesive between said outer side of said first tab and said inner wall of said body portion adhering said first tab to said inner wall of said body portion adjacent said first opposed end, said second adhesive is a more permanent adhesive than the first adhesive for more permanently adhering said first tab to said inner wall to properly align and hold said first tab in position; a third adhesive between said outer side of said second tab and said inner wall of said body portion adhering said second tab to said inner wall of said body portion adjacent said first opposed end; said tabs being adapted to be pulled apart to release said peelable adhesive and open said container.

2. The container of claim 1 wherein said body portion of said container has a first outer layer of high density polyethylene and said wall is a peelable adhesive.

3. The container of claim 1 wherein said body portion of said container is a single layer of high density polyethylene.

4. The container of claim 1 wherein said second adhesive layer is a peelable adhesive.

5. The container of claim 4 wherein said second adhesive layer is a vinyl based adhesive.

6. The container of claim 1 wherein said third adhesive is a low density polyethylene.

7. The container of claim 1 wherein said seal assembly extends across said first opposed end.

8. The container of claim 1 wherein said seal assembly extends across a portion of said first opposed end.

9. The container of claim 8, wherein said first opposed end is sealed across the entire length; and said seal assembly facilitates opening of said bag and functions as a pour spout.

10. The container of claim 7, wherein said seal assembly further includes a fourth adhesive sandwiched between said first and second tabs engaging said inner sides of said first and second tabs; said fourth adhesive is a re-sealable peelable adhesive.

11. The container of claim 8, wherein said seal assembly further includes a fourth adhesive sandwiched between said first and second tabs engaging said inner sides of said first and second tabs; said fourth adhesive is a re-sealable peelable adhesive.

12. The container of claim 10, wherein said fourth adhesive is a water and solvent based adhesive.

13. The container of claim 11, wherein said fourth adhesive is a water and solvent based adhesive.

14. The container of claim 1, wherein said seal assembly further includes an elongated snap fastener disposed between said first and second tabs such that said container can be re-sealed after being opened.

15. The container of claim 1, wherein at least one of said first and second tabs are brightly colored.

16. A seal assembly for use in a container having first and second opposed ends and an interior cavity defined by an inner wall, said seal assembly comprising: opposed first and second tabs with each of said tabs having inner and outer sides; a first peelable heat resistant adhesive sandwiched between said first and second tabs engaging said inner sides of said first and second tabs; said outer side of said first tab having a second more permanent adhesive than the first peelable heat resistant adhesive which is adapted to be secured to the inner wall of the container for positioning and adhering said first tab to the inner wall adjacent the first opposed end; said outer side of said second tab being adapted to be secured to the inner wall of the container adhering said second tab to the inner wall adjacent the first opposed end; said tabs being adapted to be pulled apart to release said peelable adhesive and open the container.

17. The seal assembly of claim 16, further including a third adhesive layer engaging said outer side of said second tab and adapted to secure said outer side of said second tab to the inner side of the container.

18. The flexible bag of claim 16, wherein said second adhesive layer is a peelable adhesive that more permanently adheres said first tab to the inner wall of the container.

19. The flexible bag of claim 18, wherein said second adhesive layer is a vinyl based adhesive.

20. The flexible bag of claim 16, wherein said second adhesive layer is a vinyl based adhesive.

21. The flexible bag of claim 19, wherein said third adhesive is a low density polyethylene.

22. The container of claim 16, wherein said seal assembly further includes a fourth adhesive sandwiched between said first and second tabs engaging said inner sides of said first and second tabs, such that said container can be re-sealed after being opened.; said fourth adhesive is a re-sealable peelable adhesive.

23. The container of claim 22, wherein said fourth adhesive is a water and solvent based adhesive.

24. The container of claim 16, wherein said seal assembly further includes an elongated snap fastener disposed between said first and second tabs such that said container can be re-sealed after being opened.

25. The container of claim 16, wherein at least one of said first and second tabs are brightly colored.

26. A method of making a container having a seal assembly, said method comprising steps of: providing a container having an inner wall defining an interior cavity and first and second opposed ends; providing a seal assembly having opposed first and second tabs with each of said tabs having inner and outer sides; sandwiching a first peelable heat resistant adhesive between said first and second tabs engaging said inner sides of said first and second tabs; positioning and adhering with a second more permanent adhesive than said first peelable heat resistant adhesive said outer side of said first tab to said inner wall of said container adjacent said first opposed end; adhering with a third adhesive said outer side of said second tab to said inner wall of said container adjacent said first opposed end.

27. The method of claim 26, further including the steps of: providing a bagger assembly having a label placer, a filler tube, a first heat seal extending along said filler tube and a second heat seal extending across the terminal end of said filler tube; providing at least one of said seal assembly within said label placer; providing a supply of liner material having an outer surface and inner surface and side edges; feeding said liner material adjacent said label placer, controlling said label placer to dispense said seal assembly from said label placer and positioning said second permanent adhesive on said outer side of said first tab to said inner surface of said liner material; feeding said liner around said filler tube and joining said side edges against each other, engaging said first heat seal against said joined edges sealing said joined edges together to define a body portion having said first and second opposed ends; engaging said first and second opposed ends with said second heat seal to seal said second opposed end and engaging said first opposed end adjacent said seal assembly to heat seal said second tab liner with said third adhesive to said inner surface without melting said first and second tabs together.

28. The method of claim 27, further including the step of continuously forming said container wherein said first opposed end of said container is adjacent said second opposed end of said next container; said second heat seal seals said second opposed end and adheres said seal assembly to said first opposed end and cuts said liner between said first and second opposed ends to create a first container having said opposed ends sealed and a second container having said second opposed end sealed and said first opposed end prepared to be sealed when said second opposed end reaches said second heat seal.

29. The method of claim 26, further including the step of filling said container with a product through said fill tube as said container is being formed around said fill tube.

30. The method of claim 26, further including the steps of brightly coloring at least one of said first and second tabs.