WO2002014153A1

WO2002014153A1 - Recloseable bags with tamper-evident zipper and methods of manufacturing the same

Info

Publication number: WO2002014153A1
Application number: PCT/US2001/023882
Authority: WO
Inventors: Timothy W. Pistner; Toby R. Thomas; Nathan A. Kolovich
Original assignee: Pactiv Corporation
Priority date: 2000-08-16
Filing date: 2001-07-30
Publication date: 2002-02-21
Also published as: AU2001279084A1

Abstract

A recloseable bag and a method of manufacturing recloseable bags utilizes a track or fastener (14) having a male track with a male profile, a female track with a female profile and fins (28,34) extending from the profiles. The male and female profiles are releaseable engageable to each other. A web of bag material is advanced and slit to form coplanar, side-by-side web portions (16 and 18). Each of the fins is sealed to one of the facing surfaces at first edges of the side-by-side web portions so as to attach the track with its releasably engageable profiles between the two web portions. The fins may be joined along an edge opposite the profiles, and scored to define a tamper-evident feature.

Description

RECLOSEABLE BAGS WITH TAMPER-EVIDENT ZIPPER AND METHODS OF MA JFACTTJRING THE SAME

FIELD OF THE INVENTION

The present invention relates generally to the packaging industry. More particularly, the invention relates to a recloseable bag or package having a zipper or fastener with a tamper-evident feature and a method of manufacture of such a bag.

BACKGROUND OF THE INVENTION

Plastic packages are popular for storing food products and other items. Recloseable packages that can be securely closed and reopened are particularly popular due to their ability to maintain freshness of the food stored in the package and/or to minimize leakage into and out of the package. Thus, recloseable packages are very common, especially in the food industry. Recloseable packages are typically made to be recloseable via the use of a recloseable feature such as a resealable adhesive seal or a recloseable zipper. Recloseable zippers can be opened and closed either by pressure or by the use of an auxiliary slider mechanism. These packages are used one at a time by consumers and large numbers of these packages are also used by businesses to package items that are then sold to consumers. An example of a business that uses a large number of these packages is a food producer and packer. For example, nuts, candy, snacks, salt, cheese, other food and non-food products can be packed in these packages by form, fill and seal machines and sold to consumers.

In addition to the recloseable zipper, it is often desirable to have another closure for the package. For example, some packages are provided with a closure which may first be opened by slitting or cutting, with the zipper fastener feature thereafter being used to reclose the package, that is, after the initial opening. It is also sometimes desirable that the additional closure feature have a tamper-evident feature associated with it. That is, the additional closure is so constructed, that once slit, cut or otherwise opened, it is immediately evident to the user that this closure has been opened completely or partially, such as by being completely or partially cut, punctured, or the like. Stated another way, this additional closure is not a refastenable or recloseable in the same fashion as the recloseable zipper fastener feature. A need therefore exists for an efficient method and apparatus for providing products within a recloseable package. Additionally, a need exists for a recloseable bag having a fastener and a tamper evident feature that can easily and efficiently be manufactured.

SUMMARY OF THE INVENTION

In one aspect of the present invention, there is provided a fastener arrangement for use in manufacturing recloseable bags. The fastener arrangement comprises a first fastener releasably engageable to a second fastener. Each of the fasteners comprises a zipper having a male track with a male profile and a female track with a female profile. The male and female profiles are releasably engageable to each other. The male track and female track are mounted to either side of a web of material which includes a tamper-evident feature. This web of material may be secured at either side of the fastener profiles, to first and second wall panels of a bag or package. Opposite free ends of the wall panels may then be joined, and cross-seamed to form individual packages or bags. The individual packages or bags may be filled with product. Any of a variety of form- fill-seal operations may be used following the securing of wall panels to the web. hi another aspect of the present invention, a slider is slidably mounted to the zipper for movement between a closed position and an open position. The male and female profiles are engaged to each other while the slider is in the closed position. The male and female profiles are disengaged from each other in response to movement of the slider from the closed position to the open position.. The zipper may have a length approximately equal to a length (or width) of the recloseable package.

In a further aspect of the present invention, there is provided a zipper arrangement for use in manufacturing recloseable bags. The zipper arrangement comprises a male track with a male profile and a female track with a female profile. The male and female profiles are releasably engageable to each other. The male track and female track are mounted to either end of a web of material which includes a tamper-evident feature. This web of material may be secured at either side of the fastener profiles, to first and second wall panels of a bag or package. Opposite free ends of the wall panels may then be joined, and thereafter, cross-seamed to define individual packages or bags. The individual packages or bags may be filled with product. hi accordance with another aspect of the present invention, a web from which the walls of the package or bag are formed may be initially fed off a film roll from an unwind operation. Thereupon, the web is slit to form two coplanar or side-by-side continuous webs. At this point, a zipper having engaged male and female profiles and a tamper evident feature is secured to adjacent surfaces of the side-by-side web portions.

Thereafter, the bag web panels may be folded as in a horizontal form fill seal operation, or alternatively, wrapped around a tube as in a vertical form fill seal operation, or even used to over-wrap product. Advantageously, the manner in which the web is initially slit and the zipper is secured to the respective split web portions closely following the unwind process, permits this process to be used in any of a variety of form, fill and seal or overwrap operations. Generally speaking, the unwind process and mechanism is common to all of these forms of form, fill and seal or over- wrap operations. an alternate embodiment, the webs which form the bag panel may be separately fed, rather than slitting a single web. In a further aspect of the present invention, there is provided a method of manufacturing recloseable packages. The method comprises providing a first wall panel and a second wall panel, positioning a zipper comprising releasably engageable zipper profiles on a zipper web between the first and second wall panels, adhering a surface of the zipper web on one side of the zipper profiles to the first wall panel, and adhering a surface of the zipper web on the other side of said zipper profiles to the second wall panel. The method may further include joining opposite free ends of the first and second wall panels, forming a first and a second side seal in the wall panels to define a first and a second side edge of the package, and cutting the side seals to separate adjacent packages. The method may further include feeding a zipper arrangement between the wall panels before positioning the zipper. The zipper may alternatively comprise a continuous male track and a continuous female track with a plurality of sliders.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings: FIG. 1 is a cross-sectional view of a fastener or track having a web or fins;

FIG. 2 is a cross-sectional view similar to FIG. 1 showing a fastener or track with split fins; FIG. 3 is a perspective view of the fastener or track of FIG. 1 preparatory to being applied to a slit web;

FIG. 4 is a perspective view showing an unroll and slit operation and the assembly of the fastener or track with the split web; FIG. 5 is an enlarged cross-sectional view showing the track or fastener being applied to the split web;

FIG. 6 is a cross-sectional view showing web panels folded downwardly, subsequent to the process shown in FIGS. 4 and 5;

FIG. 7 is a partial perspective view showing an assembled fastener and wall panels, additionally using a slider;

FIG. 8 is a simplified view of a form, fill and seal process using the fastener and bag formed by the process of FIGS. 4 and 5;

FIG. 9 is a simplified view of a vertical form, fill and seal process using the invention; and FIGS. 10-12 show further embodiments of a fastener or track having a web or fin.

While the invention will be described in connection with certain preferred embodiments, it is not intended to limit the invention to the specific exemplary embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Turning now to the drawings, FIGS. 1-3 illustrate a fastener or zipper arrangement or "track" 14 for recloseable bag or package. The track 14 includes a male track 24 having a male profile 26 and a first fin or web portion 28 extending from the male profile 26, and a female track 30 having a female profile 32 and a second fin or web portion 34 extending from the female profile 32. The male and female profiles 26 and 32 are releasably engageable with each other to provide a recloseable seal for a bag or package. In the illustrated embodiment of FIGS. 1 and 3, the lower edges of the first and second fin or web portions 28 and 34 are joined to each other along a one-time breakable preferential area of weakness or preferential tear area 38 to for a one-time openable tamper evident feature. The tamper evident feature is described in detail in Serial No.

08/694,093 to Thomas et al., which is incorporated herein by reference in its entirety. Other embodiments of the fastener 14 may not include the tamper evident feature leaving the fin portions 28 and 34 disconnected, as shown in FIG. 2. Referring now to FIGS. 4 and 5, a novel part of the method or process of forming a bag in accordance with the invention as illustrated. In FIG. 4, an unwind portion of the process is also illustrated. The web material from which the bag or package is to be formed is indicated generally by reference numeral 42. The web or film 42 is unrolled or removed from a roll 40. In accordance with one embodiment of the invention, a knife, razor blade or other suitable slitting tool 44 is used to slit the web 42 into two side-by- side coplanar web portions 16, 18 which will ultimately form the opposing wall panels of a package or bag body. Two side-by-side rolls 40 dispensing separate webs 16, 18 might also be used; however, synchronizing means might be required for this option. The web or film 42 and hence these wall panels 16 and 18 may comprise polymeric film, multi- layer and multi-component laminations or co-extrusions.

In accordance with one aspect of the invention, the fastener or track 14 is fed or otherwise positioned intermediate the web portions 16 and 18, as also shown in FIG. 5. Thereupon, the fins or web portions 28 and 34 of the track may be adhered to surfaces at respective opposite inwardly facing edges of the respective web portions or wall panels 16 and 18. The sealing or adhering of the fins to the web portions 16 and 18 may be by heat seal, adhesive or any other appropriate method to form a strong seal. As shown in FIGS. 3, 4 and 5, the fins 28 and 34 are pressed or otherwise deformed into a partially flattened condition, to permit the sealing or adhering of an outer surface thereof to the coplanar side-by-side and somewhat spaced apart web portions 16 and 18. In the case where a tamper-evident feature is not provided and the fins are independent or split (see FIG. 2), the fins may be completely spread in a generally parallel configuration to the web portion 16 and 18 to facilitate sealing. In this instance, the fins may be somewhat shorter than illustrated in FIG. 2, having sufficient length to permit adequate adhering or sealing to opposed facing edge portions of the web portions 16 and 18. Referring next to FIG. 6, following application of the track 14 to the bag wall panels or web portions 16, 18, the bag may be further processed such as by folding the webs or wall panels 16, 18 into the configuration shown in FIG. 6. Advantageously, following the process shown in FIGS. 4 and 5, the panels 16, 18 and track 14 may be further formed in a variety of ways, either by folding as shown in FIG. 6 for use in a horizontal fill operation or by wrapping about a fill tube (FIG. 9) for use in a vertical fill operation, or in an overwrap application, being applied or overwrapped about a food product or other product (not shown).

The track 14 may include recloseable interlocking profiles 32 and 26 for manual engagement and disengagement, or, referring to FIG. 7, may additionally include a slider 12 for opening and closing the profiles. For a variety of reasons, including difficulty in closing the zipper, some consumers prefer an easier way to open and close the zippers on these packages. As a result, zipper packages with the slider to open and close the zipper have become popular with consumers. Product manufacturers, however, have rarely used the zipper with slider in their form, fill and seal machines because there has not been a way to assemble and accumulate the zippers with sliders in a configuration that can be easily and quickly fed to the form, fill and seal machines. h FIG. 7, the recloseable package 20 has a slider 12 slidably mounted to the fastener 14 for movement between a closed position and an open position. The male and female profiles 26 and 32 are engaged to each other while the slider 12 is in the closed position, and movement of the slider 12 from the closed position to the open position disengages the profiles 26 and 32 from each other. FIG. 7 depicts the open position to the left of the slider 12 and the closed position to the right of the slider 12. The composition and manner of operation of the fastener with slider arrangement is described in detail in U.S. Patent No. 5,067,208 to Herrington, Jr. et. al., which is incorporated herein by reference in its entirety.

FIG. 8 illustrates one embodiment of a (horizontal) fill and seal process for providing a product within a recloseable package having the fastener 14 with slider 12, formed as described above. The process of providing the packaging material having the fastener 14 attached is as shown in FIGS. 4 and 5, and sides are folded down as shown in FIG. 6. This forms a package body 20 and defines a receptacle space 22 bounded by the opposing wall panels 16 and 18 (see FIG. 6) and the closed fastener or zipper 14. The fastener 14 (shown with optional slider 12 in FIG. 8) is in the closed position when fed to the fill and seal apparatus of FIG. 8. A vertical seal bar 58 joins the wall panels 16 and 18 together to form a side seal

60 that defines a side edge 62 of the recloseable package. The distance between adjacent side seals 60 should be approximately equal to the desired width W of the recloseable package. The side seal 60 may be formed by heat seal, adhesive or any other appropriate method to form a strong preferably hermetic seal. In the embodiment depicted, the side seal 60 is formed at an optional notch 63 in the zipper arrangement 14 which allows easier side sealing since the vertical seal bar 58 does not have to flatten or crush the profiles 26 and 32 of the fastener 14 in order to side seal the web 16, 18. Once the side edges 62 of the package are defined by the side seal 60, a product 64 fills the receptacle space 22 of the package. For illustration, FIG. 8 shows a funnel 66 directing the product 64, into the package. The product 64 may be nuts, candy, snacks, salt, cheese and/or other food and non-food products.

After the product 64 fills the package, a top seal bar 68 adheres the wall panel 16 to the other wall panel 18, hermetically sealing the product 64 within the package. The top seal bar 68 moves back and forth to provide a seal 70 that adheres the wall panel 16 to the wall panel 18. The wall panels 16 and 18 maybe sealed by heat seal, adhesive or any other appropriate method to form a strong hermetic seal 70. To divide the adjacent packages of product 64 that are connected by the side seal 60, a knife 72 cuts the side seal 60 such that the side edges 62 of each package remain secure. An end termination or stop (not shown) may be added to the ends of the fastener

14 for inhibiting or preventing the slider 12 from going past the ends of the zipper. The end terminations also hold the male and female profiles together to resist stresses applied to the profiles during normal use of the plastic bag. One type of end termination is in the form of a strap/clip that wraps over a top of a zipper. Further information concerning such an end termination may be found in U.S. Patent No. 5,067,208, which is incorporated herein by reference in its entirety. One end of the strap is provided with a rivet-like member that penetrates through the zipper fins and into a cooperating opening at the other end of the strap. Other types of end termination are disclosed in U.S. Patent Nos. 5,482,375, 5,448,807, 5,442,837, 5,405,478, 5,161,286, 5,131,121 and 5,088,971, which are each incorporated herein by reference in their entireties.

The form, fill and seal process may vary from the illustration of FIG. 8 and the following describes some of the possible variations. In another embodiment of the form, fill and seal process, the side seal 60 may be cut before filling the package with the product 64. In this embodiment, the process forms and cuts the side seals 60. After the knife 72 cuts the side seals 60, the product 64 fills the package and the seal 70 closes the package. As mentioned above, the bag panels or web portions 16, 18 and track or fastener 18 joined as shown in FIGS. 4 and 5 may be used in connection with other form, fill and seal operations or processes, including a vertical form, fill and seal operation or an overwrap operation. The horizontal process shown in FIG. 8 gives but one example of a fill process which may be utilized in connection with the invention. Other fill and seal processes may be used, including vertical and overwrap. Referring to FIG. 9, a vertical form fill and seal (VFFS) operation is illustrated somewhat diagrammatically. In this regard, the form fill seal operation in FIG. 8 may be what is often referred to as a horizontal form fill seal (HFFS) operation. In FIG. 9, similar reference numerals with the prefix 1 have been used to designate parts and components which are similar to those designated in the previous figures of drawings. In FIG. 9, the web 42 is supplied on a roll 140 in an unwind process, similar to the above description, separate side-by-side rolls 140 might also be used. In the event a single web is used, it is split or slit by a knife or razorblade 144 and a fastener or zipper strip or track 114 is supplied in generally the same form as illustrated above for attachment to the two web portions 116 and 118. The zipper strip may be supplied from a reel 115. An attachment tool 117 may be used to attached the strip 114 to the web in the same fashion as illustrated above in FIGS. 3, 5 and 6, for example. In the event a slider is utilized, the slider 112 may next be attached to the fastener strip 114.

Thereafter, in a vertical form fill and seal (VFFS) operation, the web and slider are fed through a forming collar 80 about a vertical fill tube 82 into which product is introduced through a funnel 166. The funnel 166 and tube 82 may be a single piece. A bottom seal (with respect to the orientation of the finished product, wherein the zipper strip is at the top) is formed by a suitable sealing tool 168, and transverse side seals are formed by sealing tools 158. The product may be filled following the formation of the first side seal, and then, as the web advances, the second side seal may be formed, and thereafter, the web may be cut adjacent the second side seal as by cutting tools 172 to separate the filled package from the web. Referring to FIGS. 10-12, like reference numerals to those used in FIGS. 1-3, 5 and 6 with prefixes 10, 11 and 12 are utilized to designate like parts and components of three alternate forms of configurations of the fastener or zipper strip with fins or web portions extending therefrom. It will be noted that the embodiment of FIG. 12 differs from that shown for example in FIG. 1 in that the tamper evident feature is formed on the inner side of the web.

While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A method of forming a package, said method comprising: providing a continuous elongated web of package material; longitudinally slitting said web to form first and second coplanar side-by-side web portions; providing a track having interengaged male and female profiles and a fin extending from each of said male and female profiles; positioning said track between facing inner surfaces at first edges of said side-by- side web portions; and attaching each of said fins to one of the facing surfaces of the side-by-side web portions.

2. The method of claim 1 and further including providing said fins as a single continuous web of material joining the male and female profiles, and providing a longitudinal score in said continuous web of material to define a tamper-evident feature in said web between said male and female profiles.

3. The method of claim 1 and further including joining edges of said web portions opposite the edges thereof joined to said track.

4. The method of claim 3 and further including forming first and second, spaced apart transverse seals in a direction transversely to said track.

5. The method of claim 4 and further including, prior to said j oining of said edges opposite said track, filling said package with product.

6. The method of claim 5 and further including cutting said web at said transverse seals to separate individual packages following filling said packages with product.

7. The method of claim 5 and further including cutting said web at said transverse seals to define individual packages before filling each package with product.

8. The method of claim 1 and further including forming said side-by-side web portions about a generally vertically disposed fill tube; forming a transverse seal across said web portions in a direction transversely to said track; filling said package with product, forming a second transverse seal above a portion of said package filled with product, and cutting transversely at said second transverse seal to separate an individual package from the web.

9. The method of claim 1 and further including folding said side-by-side web portions into a generally parallel configuration, forming first and second spaced apart transverse seals in a direction transversely to said track, filling said package with product

5 and joining edges of said web portions opposite the edges thereof joined to said track.

10. The method of claim 9 and further including cutting said web at least at one of said transverse side seals prior to filling said package with product.

11. The method of claim 10 and further including cutting said web at least at one of said transverse side seals following filling the package with product. lo

12. The method of claim 4 and further including, prior to forming said second transverse seal, filling said package with product.

13. The method of claim 12 and further including cutting said web at said transverse seals to separate individual packages following filling said packages with product. ι₅

14. The method of claim 1 and further including folding said side-by-side web portions into a generally parallel configuration and forming first and second spaced apart transverse seals through said web portions in a direction transversely to said track.

15. The method of claim 14 and further including filling said package with product. 20

16. The method of claim 15 and further including joining edges of said web portions opposite the edges thereof joined to said track.

17. The method of claim 16 and further including cutting said side seals to separate individual packages following filling said packages with product.

18. The method of claim 5 and further including cutting said web at said

25 transverse seals to define individual packages before filling each package with product.

19. A method of forming a package, said method comprising: providing first and second coplanar, side-by-side, continuous elongated webs of package material; providing a track having interengaged male and female profiles and a fin 30 extending from each of said male and female profiles; positioning said track between facing inner surfaces at first edges of said side-by- side web portions; and attaching each of said fins to one of the facing surfaces of the side-by-side web portions.

20. The method of claim 19 and further including providing said fins as a single continuous web of material joining the male and female profiles, and providing a longitudinal score in said continuous web of material to define a tamper-evident feature in said web between said male and female profiles.

21. The method of claim 14 and further including and joining edges of said web portions opposite the edges thereof joined to said track.

22. The method of claim 21 and further including forming first and second, spaced apart transverse seals in a direction transversely to said track.

23. The method of claim 22 and further including, prior to said j oining of said edges opposite said track, filling said package with product.

24. The method of claim 23 and further including cutting said side seals to separate individual packages following filling said packages with product.

25. The method of claim 23 and further including cutting said side seals to define individual packages before filling each package with product.

26. The method of claim 19 and further including forming said side-by-side web portions about a generally vertically disposed fill tube, forming a transverse seal across said web portions in a direction transversely to said track filling said package with product, forming a second transverse seal above a portion of said package filled with product, and cutting transversely at said second transverse seal to separate an individual package from the web.

27. The method of claim 19 and further including said side-by-side web portions into a generally parallel configuration, forming first and second, spaced apart transverse seals in a direction transversely to said track, filling said package with product and joining edges of said web portions opposite the edges thereof joined to said track.

28. The method of claim 27 and further including cutting said web at least at one of said transverse side seals prior to filling said package with product.

29. The method of claim 28 and further including cutting said web at least at one of said transverse side seals following filling the package with product.

30. The method of claim 22 and further including, prior to forming said second transverse seal, filling said package with product.

31. The method of claim 30 and further including cutting said web at said transverse seals to separate individual packages following filling said packages with product.

32. The method of claim 19 and further including folding said side-by-side web portions into a generally parallel configuration and forming first and second spaced apart transverse seals through said web portions in a direction transversely to said track.

33. The method of claim 32 and further including filling said package with product.

34. The method of claim 33 and further including joining edges of said web portions opposite the edges thereof joined to said track.

35. The method of claim 34 and further including cutting said side seals to separate individual packages following filling said packages with product.

36. The method of claim 25 and further including cutting said web at said transverse seals to define individual packages before filling each package with product.