Methods of making slide-zippered reclosable packages on horizontal form-fill-seal machines

Abstract
Methods of making slide-zippered reclosable packages are provided. In one embodiment, a pair of opposing film extensions are provided on each package between which a zipper and slider are attached. In another embodiment, sliders are inserted on to zippered packages output from a form-fill-seal machine or the like. In yet another embodiment, during package formation a reclosable zipper is sealed to each package and then a slider is inserted on to the zipper. In yet another embodiment, during package formation a reclosable zipper is sealed to each package and a slider is inserted on to each zipper, either before or after zipper sealing.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to the field of reclosable packaging. More particularly, the present invention relates to methods of making reclosable packages having slide zippers on horizontal form-fill-seal (HFFS) machines.




2. Description of the Prior Art




Methods of making reclosable packages on various types of HFFS machines are well-known in the reclosable packaging art, such as that disclosed in U.S. Pat. No. 4,876,842. Slide zippers, i.e., plastic zippers opened and closed by a slider, are likewise well-known in the reclosable packaging art. Examples of several types of slide zippers can be found in U.S. Pat. Nos. 5,007,143, 5,008,971, 5,131,121 and 5,664,299.




The reclosable packaging art, however, is virtually, if not totally, silent as it relates to the manufacture of slide-zippered packages on HFFS machines. Because of the facility which is provided by slide zippers to consumers of reclosable packages and because of the large volume of reclosable packages made on HFFS machines today, it is highly desirable and advantageous to combine the two technologies so that slide-zippered reclosable packages can be made on HFFS machines.




SUMMARY OF THE INVENTION




Accordingly, the object of the present invention is to provide methods of making slide-zippered reclosable packages on HFFS machines.




According to a first embodiment of the present invention, a chain of packages is formed, filled and sealed on an HFFS machine or the like. A pair of opposing film extensions are provided on each package. As the chain of packages is indexed forwardly, a reclosable zipper is inserted between the film extensions of the leading package and sealed thereto. A slider is then inserted on to the reclosable zipper of the leading package and the completed leading package is cut from the chain.




According to a second embodiment of the present invention, packages having reclosable zippers are output from an HFFS machine or the like, either individually or in a chain. A slider is then inserted on to the zipper of each package in turn.




According to a third embodiment of the present invention, packages are formed, filled and sealed on an HFFS machine or the like. During package formation, a reclosable zipper is sealed to each package and then a slider is inserted on to the zipper.




According to a fourth embodiment of the present invention, packages are formed, filled and sealed on a horizontal form-vertical fill-seal (HVFS) machine or the like. During package formation, a reclosable zipper is sealed to each package and a slider is inserted on to each zipper, either before or after zipper sealing.




The present invention will now be described in detail, with frequent reference being made to the drawings identified below in which the same numerals represent the same elements.











BRIEF DESCRIPTION OF THE DRAWINGS




In the accompanying drawings:





FIG. 1

shows packages being made on an HFFS machine in accordance with a first embodiment of the present invention;





FIG. 2

is a perspective view of a package made on the HFFS machine of

FIG. 1

prior to attaching the zipper;





FIG. 3

is a cross-sectional view of the HFFS machine of

FIG. 1

at the slider insertion point;





FIG. 4

is a cross-sectional view of a first variation of the HFFS machine of

FIG. 1

;





FIG. 5

shows sliders being inserted on a chain of packages in accordance with a second embodiment of the present invention;





FIG. 6

shows sliders being inserted on to individual packages in accordance with a variation of the second embodiment of the present invention;





FIG. 7

shows packages being made on an HFFS machine in accordance with a third embodiment of the present invention;





FIG. 7



a


is a cross-sectional view of the HFFS machine of

FIG. 7

at the first zipper sealing station;





FIG. 8

is a cross-sectional view of the HFFS machine of

FIG. 7

;





FIG. 9

is a cross-sectional view of a package made on the HFFS machine of

FIG. 7

;





FIG. 10

shows packages being made on an HFFS machine in accordance with a variation of the third embodiment of the present invention;





FIG. 11

is a cross-sectional view of packages being made on the HFFS machine of

FIG. 10

;





FIG. 12

shows packages being made on an HFVS machine in accordance with a fourth embodiment of the present invention;





FIG. 13

shows packages being made on an HFVS machine in accordance with a first variation of the fourth embodiment of the present invention;





FIG. 14

shows packages being made on an HFVS machine in accordance with a second variation of the fourth embodiment of the present invention;





FIG. 15

is a cross-sectional view of reclosable zipper being sealed to one package side in the HFVS machine of

FIG. 14

;





FIG. 16

is a cross-sectional view of a package prior to being filled on the HFVS machine of

FIG. 14

;





FIG. 17

is a cross-sectional view of a tamper evident sealed being placed on a package made on the HFVS machine of

FIG. 14

;





FIG. 18

shows packages being made on an HFVS machine in accordance with a third variation of the fourth embodiment of the present invention; and





FIG. 19

is a cross-sectional view of a package being formed on the HFVS machine of FIG.


18


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




In accordance with a first embodiment of the present invention,

FIG. 1

shows how slide-zippered packages can be made on a typical thermoform HFFFS machine


10


. Forming film


12


is indexed off a coil


14


of the same in a package forming direction. Downstream of the forming film coil


14


at a forming station


15


the forming film


12


is thermoformed, using techniques well-known to those of ordinary skill in the reclosable packaging art, into a chain


13


of advancing box-like bottom portions or trays


16


of what will ultimately be completed packages. Product may then be loaded into the bottom portions


16


at a loading station


17


if desired. After optional product loading, top film


18


is indexed off a coil


20


of the same in the package forming direction, laid over the advancing bottom portions


16


and perimeterly sealed thereto at four locations


22


,


24


,


26


,


28


at a sealing station


21


to form a sealed package


29


, as shown in FIG.


2


. The seal at the package opening


22


takes the form of a peel seal so that the consumer can easily gain access to the contents of the package.




As shown in

FIG. 2

, which is a perspective view of a sealed package


29


formed on the thermoform HFFS machine of

FIG. 1

prior to zipper and slider insertion, the bottom portion


16


and top film


18


are each provided with film extensions


30


,


32


which extend beyond the peel seal


22


on one side of the package


29


. The film extensions


30


,


32


are not sealed to each other and may readily be spread apart from each other.




After the top film


18


is sealed to the bottom portion


16


at the sealing station


21


, the package chain


13


enters a zipper and slider insertion and attaching station


34


. At this station


34


the film extensions


30


,


32


of the leading package are spread apart from each other and interlocked reclosable zipper


36


supplied from a coil


38


of the same is fed between the film extensions


30


,


32


, as shown in

FIG. 3

, which is a cross-sectional view of the package chain and zipper and slider insertion and attaching station


34


. The zipper is comprised of two interlocking closure elements


39


,


41


and flanges


40


,


42


extending therefrom which are sealed to the film extensions


30


,


32


, such as by a pair of seal bars (not shown). After the zipper


36


is thus sealed to the film extensions of the leading package, the zipper


36


is stomped at each end of the package by a stomping apparatus (not shown) to provide end stops for the slider and to ensure that the ends of the zipper


36


do not come apart during use.




A slider


44


is then removed from a coil


46


thereof and inserted on to the zipper


36


by a slider insertion apparatus (not shown). The slider and zipper are designed such that the slider will open the zipper as the slider is moved along the zipper in an opening direction towards an opening end of the zipper and close the zipper as the slider is moved along the zipper in a closing direction towards a closing end of the zipper. It is preferable during slider insertion that the slider be inserted at the closing end of the zipper since the zipper is initially interlocked. The slider will thus be positioned for normal functioning. If the slider is inserted at a location other than at the closing end, it will be necessary to actuate the slider by moving it to the closing end, after which the slider will be in position for normal functioning. Such actuation may be done on the HIFFS machine, or it may be done by the initial package user.




After slider insertion, the leading package is cross-cut from the remainder of the chain


13


by any one of many commonly known cutting apparatuses (not shown) to remove a completed package


48


having a slide zipper.




In practice, the package chain


13


may be a single chain as shown in

FIG. 3

, or, alternatively, may be a multiple chain, such as the double chain


50


shown in cross-section in FIG.


4


. In the case of a double chain, where two packages are joined side by side, the process of making the packages is virtually identical to that described above, except that the zippers and sliders are attached to the opposite sides


47


,


49


of the package chain simultaneously, as shown in

FIG. 4

, thus requiring two zipper and slider insertion and attaching stations


34


. Additionally, a second cut is needed in the machine direction along the central axis


51


of the chain to remove the side-by-side packages from one another.




The foregoing embodiment of the present invention is not limited to practice on thermoform HFFS machines, but may be practiced on any type of package making machine where the packages are formed with film extensions


30


,


32


of the type discussed above.





FIGS. 5 and 6

depict a second embodiment of the present invention. Zippered packages


52


, either in a chain


54


as shown in

FIG. 5

or individually as shown in

FIG. 6

, are output from an HFFS machine (not shown), or any other type of bag making machine. In the case of

FIG. 5

, the package chain


54


is indexed into a slider insertion station


56


. At the slider insertion station


56


or at an earlier station, the ends of the zipper


36


on the leading package in the chain


54


are stomped as discussed above. Then, a slider


44


is removed from the slider coil


46


and inserted on to the zipper


36


. Finally, a completed package


58


have a slide zipper is cross-cut from the chain by a cutting apparatus (not shown).




In the case of

FIG. 6

, the packages


52


are individual and not chained together. The individual packages


52


are transported one by one into the slider insertion station


56


by a conveyor belt


60


or the like, where the ends of the zipper


36


on the leading package are stomped (unless the stomping was done during package formation) and a slider


44


is removed from the slider coil


46


and inserted on to the zipper


36


to provide a completed slide-zippered package


58


.




In accordance with a third embodiment of the present invention,

FIG. 7

shows a thermoform HFFS machine


62


configured to make slide-zippered packages. As in

FIG. 1

, the forming film


12


is indexed off a coil


14


of the same. Downstream of the forming film coil


14


at a forming station


15


the forming film


12


is thermoformed into a chain


13


of box-like bottom portions or trays


16


of what will ultimately be completed packages. Product may then be loaded into the bottom portions


16


at the loading station


17


if desired. Each bottom portion


16


is provided with a lip


64


on one side thereof, as shown in

FIG. 8

, which is a cross-sectional view of the chain


13


. After optional product loading, the reclosable zipper


36


is indexed off a coil


38


of the same and laid over the lips


64


of the bottom portions


16


. The lower zipper flange


42


is then sealed to the lips


64


by a sealing mechanism, such as a heater bar


63


, at a sealing station


68


. The heater bar


63


is positioned below the lips


64


, as shown in

FIG. 7



a,


which is a cross-sectional view of zipper attachment to the package lips. Also shown in

FIG. 7



a


is an insulating and guide plate


67


positioned between the zipper flanges. The insulating and guide plate


67


provides a surface for the heater bar to react against and removes any danger of sealing through the zipper flanges, thereby eliminating the need for accurate heat control. The insulating and guide plate


67


also serves to guide and position the zipper onto the package lips to ensure accurate sealing.




A slider


44


is then removed from the slider coil


46


and inserted on to the zipper


36


of the instant bottom portion


16


at an insertion station


70


. After slider insertion, the ends of the zipper are stomped. Alternatively, the zipper ends could have been stomped together earlier, either on the machine or pre-stomped prior to winding on the supply coil, and the zipper indexed to the bottom portion. The top film


18


is then indexed off the top film coil


20


, laid over the formed bottoms


16


and the attached zipper


36


and sealed to the formed bottoms


16


and the upper flange


40


of the zipper


36


around the perimeter of the package at a second sealing station


72


. As discussed above, the seal at the mouth of the package may take the form of a peel seal to provide easy access to the contents of the package. Optionally, the top film


18


, if it is long enough, may be heat tacked to the bottom portion


16


over the zipper


36


to provide a tamper evident seal


65


, as shown in FIG.


9


. In the final step, the completed packages


48


are cross-cut from the chain at a cutting station


74


. If a double chain is used, as shown in

FIG. 8

, then the side-by-side packages must also be cut from each other in the machine direction.




When making packages using multiple package chains, it is not necessary that the zippers and sliders be applied to opposite sides


47


,


49


of the package chain, as shown in

FIGS. 4 and 8

. Rather, it is also possible to apply the zippers and sliders to the same sides of the packages. For example, a triple package chain is shown in

FIGS. 10 and 11

. In this case the top film


18


is pre-perforated so that it can be split into three sections and laid over each of the bottom portions


16


. This splitting is achieved by a separator assembly


78


having three L-shaped separator plates


78




a,




78




b,




78




c.


As the top film


18


is indexed off its roll


20


, the vertical portions of the separator plates


78




a,




78




b,




78




c


split the pre-perforated top film


18


into three portions


18




a,




18




b,




18




c


and guide the three top film portions as they are laid over their corresponding bottom portions


16


. Additionally, the horizontal portions of the separator plates interact with the sealing mechanism to ensure that there is no seal through, eliminating the need for accurate heat control.




As indicated above, the present invention is not limited to thermoform HFFS machines, but may be practiced on any type of HFFS machine and on any type of bag making machine for that matter.

FIG. 12

shows how slide-zippered packages can be made on a horizontal form-vertical fill-seal machine (HFVS)


80


in accordance with a fourth embodiment of the present invention.




Package film


82


is paid off a roll


84


of the same. Downstream a pull roller


98


is provided for driving the film


82


through the machine. A folder plow


86


positioned downstream of the film roll


84


folds the package film


82


about a bottom crease


83


to form opposing package walls


116


,


118


. Interlocked reclosable zipper


36


is then paid off a roll


38


of the same and fed between the advancing package walls. Sliders


44


are inserted on to the reclosable zipper


36


prior to the folder plow


86


at package width intervals at what will be the closing end of the zipper by a slider insertion mechanism at the slider insertion station


88


. The sliders


44


are supplied from the slider coil


46


.




At a first sealing station


90


, the zipper flanges


40


,


42


are sealed to the opposing package walls. Then at stomping stations


92


, the ends of the zipper


36


for a given package are stomped. At a second sealing station


94


, the folded film and zipper are cross-sealed to form discrete packages.




Because the zippers are closed, it is necessary to open the zippers in order to fill the packages. This is achieved at a slider opening station


96


, where the slider is held in position as the zipper and film are advanced when the pull rollers


98


are activated. As the zipper moves through the slider, it is opened. Alternatively, the slider itself may be moved. Then, at a cutting station


100


the individual packages


102


are cut from one another. The separated packages


102


are then taken to the filling station


104


where they are filled. Filling may occur by means of a filling turret


106


or the packages may be filled in-line, both of which techniques are well-known to those of ordinary skill in the art. After a package is filled, the slider


44


is moved backed to the closing end of the zipper. Finally, a tamper evident


108


seal may optionally be provided above the zipper


36


. Completed slide-zippered packages


110


are then output from the machine.




A first variation of the fourth embodiment is shown in FIG.


13


. As is clear from

FIG. 13

, the sliders are attached downstream of the folder plow


86


, rather than upstream of the folder plow


86


. Additionally, the sliders


44


are attached to the zippers


36


at their opening ends, rather than at their closing ends as above. Thus, in order to open the zippers for package filling the zippers must be forced open from the outside of the packages, rather than by using the sliders. This opening action is carried out at an opening station


97


by a suitable mechanism provided for the specific zipper construction. After filling at the filling station


104


, the slider is moved to the closing end of the zipper.




A second variation of the fourth embodiment of the present invention is shown in FIG.


14


. Under certain circumstances it may be desirable to eliminate the step of opening the zipper for filling. This can be done by sealing one zipper flange to one side of the folded film at the first sealing station


90


prior to filling, as shown in

FIG. 15

, rather than sealing both flanges to the film as done previously.




As shown in

FIG. 15

, one flange


40


of the zipper is sealed to one wall


116


of the folded film


82


a distance below the top


120


. The film


82


protrudes above the zipper to form a pair of opposing ears


122


. To ensure that the zipper flanges


40


,


42


do not seal to each other or the other side of the package at the first sealing station


90


, a J-shaped insulator plate


124


is inserted between the zipper flanges


40


,


42


and between the unsealed zipper flange


42


and the other package wall


118


, as shown in FIG.


15


. In addition, one of the seal bars


112


is kept hot and the other


114


is deactivated. Then, at the second sealing station


94


, the packages are cross-sealed from the bottom of the film


92


up to but not including the zipper. When it comes time to fill the bag at the filling station


104


, the zipper is bent to one side, as shown in FIG.


16


. In this manner, filing may proceed unobstructed, and there is no danger of contaminating the zipper. After filling, the unsealed zipper flange


42


is sealed to the other side of the package and the ears


122


are sealed to each other by a pair of seal bars


126


with a perforation seal and a peel seal above the zipper


36


, as shown in FIG.


17


. At the same time the ends of the zipper are cross-sealed together and end stops for the slider are created. The above indicated zipper cross-seals extend below the zipper flanges into the package side seals, but not above and beyond the zipper profiles.




A third variation of the fourth embodiment of the present invention is shown in FIG.


18


. In this variation, the zipper


36


and slider


44


are attached to the bottom


128


of the package, rather than at the top


120


. As the film


82


is fed over the folder plow


86


, a perforator


130


perforates the film


82


below the slider


44


to form a pair of perforations


132


(alternatively, a single perforation


132




a


may be provided). The zipper is then sealed to the bottom of the package by sealing the zipper flanges to the film beyond the perforation lines, as shown in

FIG. 19. A

peel seal


136


may be provided between the zipper flanges in order to maintain the integrity of the packages.




The packages are completed as discussed above, except that they are filled from the opposing end to which the zipper has been attached. Further, if a bottom gusset is required a V shaped film can be introduced between the package walls


116


and


118


and sealed into place. During use, the packages are inverted so that the zipper and slider are at the top and the perforated portion


134


is tom away from the package to gain access to the slider.




Thus, in the foregoing manner the object of the present invention is achieved. Modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the scope of the appended claims.



Claims
  • 1. A method of making reclosable packages freclosable packages on a horizontal form-fill-seal machine, said method comprising the steps of:feeding a supply of package film in a package forming direction; folding said package film about a bottom crease to form opposing package walls, said opposing package walls advancing in said package forming direction; feeding a supply of interlocked reclosable zipper between said opposing package walls; sealing said reclosable zipper to said opposing package walls; providing a supply of sliders, each of said sliders being insertable on to said reclosable zipper and adapted to open and close said reclosable zipper as said slider is moved along said reclosable zipper in opening and closing directions, respectively; removing sliders from said slider supply and inserting sliders on to said reclosable zipper while said reclosable zipper remains fully interlocked; cross-sealing said folded film at package-width intervals to form a chain of packages, each of said packages having a reclosable zipper and a slider; opening the reclosable zipper of each package thereby forming a mouth on an upper end of each package; filling each package through said mouth; and closing the reclosable zipper of each package.
  • 2. The method according to claim 1 wherein said sliders are inserted on to said reclosable zipper prior to said reclosable zipper being fed between said opposing package walls.
  • 3. The method according to claim 1 wherein said sliders are inserted on to said reclosable zipper after said zipper is fed between said opposing package walls.
  • 4. The method according to claim 1 wherein the reclosable zipper of each package is opened by moving its slider from a closing end of the reclosable zipper to an opening end of the reclosable zipper.
  • 5. The method according to claim 1 wherein the reclosable zipper of each package is opened by holding its slider in place as the package film is advanced in the package forming direction.
  • 6. The method according to claim 1 wherein the reclosable zipper of each package is closed by moving its slider from an opening end of the reclosable zipper to a closing end of the reclosable zipper.
  • 7. The method according to claim 1 including the step of sealing each package above its reclosable zipper to form a tamper evident seal.
  • 8. The method according to claim 1 including the step of cutting each of said packages from said chain of packages.
  • 9. The method according to claim 1 wherein the ends of the reclosable zipper of each package are cross-sealed.
  • 10. The method according to claim 1 wherein said reclosable zipper supply is stomped at package width intervals.
CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of U.S. patent application Ser. No. 09/316,866 filed on May 21, 1999 now U.S. Pat. No. 6,138,439

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3701192 Laguerre Oct 1972 A
4241865 Ferrell Dec 1980 A
4514962 Ausnit May 1985 A
4581006 Hugues Apr 1986 A
4620320 Sullivan Oct 1986 A
4654878 Lems Mar 1987 A
4665552 Lems May 1987 A
5564259 Stolmeier Oct 1996 A
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5956924 Thieman Sep 1999 A
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Number Date Country
2085519 Apr 1982 GB