Methods of making a gusset style pouch in a reclosable bag
A method for making a reclosable bag (56) with gussets (36, 38) in which a zipper profile (16) is attached to bag-making film (10), while leaving side margins (20, 22) of the film. The film (10) is folded as a tube (26). Gusset-forming wheels (34, 35) indent the tube (26) to form the side gussets (36, 38). The side gussets (36, 38) are sealed to the tube (26) and/or the zipper profile (18) with the profile sealed to the tube. The tube (26) is sealed and cross-cut to form the bag (56). In an alternative method, lengths of tubular gusset material (112) are positioned on a lower web (110) of film (101) transverse to a bag-forming direction. A zipper (124) is sealed in the bag-forming direction to the webs (108, 110), and the gusset material (112). The webs (108, 110) and the material (112) are sealed to each other to form an end seal (140) as well as cross-cut and sealed to form the gussets (144, 148) of a reclosable bag (147). The webs (108, 110) may be sealed above the zipper (124) to form a tamper-evident feature (166).
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The present invention relates to reclosable plastic bags of the type in which perishable food products and other goods are packaged for sale to consumers in retail outlets. More specifically, the present invention relates to a method for concurrently manufacturing plastic bags with gussets in the pouch of the bag.
DESCRIPTION OF THE PRIOR ARTThe present invention relates to improvements in the package-making art and may be practiced in the manufacture of reclosable plastic bags and packages of the type that may be used for various consumer products. Such packages often include a form of peel-seal to render the package moisture-tight and/or airtight prior to the initial opening, and/or for use as a tamper-evident seal. A zipper means protects any remainder of the product therein after the initial opening.
The indicated art is fairly well-developed but nevertheless remains open to improvements contributing to increased efficiency and cost-effectiveness. In the prior art, McMahon et al. (U.S. Pat. No. 4,909,017) discloses a method for making a package with a reclosable fastener on a form-fill-and-seal machine. Prior to entering the form-fill-and-seal machine, zippers are attached to the surface of the film used to make the package, with the zippers transversely attached to the running direction of the film at bag-length intervals. Only one of the interlocking profiles of the zipper is attached by its flange section to a surface of the film with the other interlocked profile facing upwardly or, in other words, inwardly toward the interior of the bag to be formed. The film is advanced to the form-fill-and-seal machine and drawn down over a forming collar and about the filling tube, with the longitudinal side edge margins of the film brought together and seamed with a fin seal to form a tube. Cross-seals are made on the tube to join the unattached profile of the zipper to the film and to form the ends of the bag and following bags.
The commonly assigned patent application “Process and Apparatus for Forming Packaging Bags With a Fastener” (U.S. Ser. No. 09/633,944, allowed Jul. 26, 2002) discloses a method in which a slider for opening and closing the fastener is attached to the fastener before the fastener is attached to the film being advanced to the form-fill-and-seal machine. Various components of the form-fill-and-seal machine allow the fastener with attached slider to advance in the machine and to be part of the formed reclosable bag.
The commonly assigned patent application “Method of Forming Gusseted Reclosable Bags” (U.S. Ser. No. 09/726,731, allowed Oct. 2, 2002) discloses a method for forming the reclosable packaging with gussets. In the method, first and second carrier webs are provided which include discrete mating zipper profile sections. The zipper profile sections are separated from each other on the carrier web by zipper-free sections of the carrier web. The carrier webs are attached to the first ends of first and second bag wall films as the bag wall films, respectively, are brought together. The bag wall films may be separate webs or a single longitudinally folded web. The carrier webs are formed of thinner-gauge plastic film than the bag wall films. The first and second bag wall films and the first and second carrier webs are cross-sealed with the carrier webs being sealed through the zipper-free sections of the web, and the assembly is transversely cut through the cross-seals to form a bag. A second end gusset is formed in the bag by reverse-folding the second end of the bag walls. If the bag walls are formed from separate films, the films must be connected either by simply sealing the second ends of the bag wall film to each other or by sealing a folded second end web to the second ends of both bag wall films. Side gussets are then formed by pushing in the end parts of the bag walls as well as the zipper-free sections of the carrier web between the open zipper sections.
An improvement in the above methods and the apparatus used in the above methods is the ability to provide side gussets in the pouch portion of the reclosable bags to be formed, in which the side gussets are formed in the pouch portion or in which a length of gusset material is sealed in the pouch portion in a manner that would not restrict the opening of the reclosable bag nor affect the use of the interlocking elements of the zipper of the bag.
SUMMARY OF THE INVENTIONAccordingly, the present invention relates to a method for producing reclosable plastic bags with expandable gussets in which the bags are manufactured in an efficient manner that readily lends itself to automated production.
In a first embodiment of the present invention, a first interlocking profile of a length of zipper is attached by one of its flanges to a mid-portion of a continuous length of bag-making film at a direction transverse to the running direction of the film, while leaving side margins of film on opposite ends of the zipper so that the combined length of the side margins of film is greater than the length of the zipper.
As the bag-making film is advanced, the side margin on one end of the zipper is sealed to the side margin on an opposite end of the zipper to form a fin seal. The fin seal forms the longitudinal seam of a tube with an inside surface of the rear wall of the tube facing the unattached profile of the zipper. As the tube is advanced, retractable gusset-forming wheels wedge and indent the side margins to form side gussets such that the base of the formed side gussets defines the longitudinal borders of the rear wall.
For a zipper with an inserted slider, the retractable gusset-forming wheels form the side gussets adjacent the interlocking elements of the zipper to allow the slider to fully open and close the interlocking elements. The amount and size of the gusset-forming wheels extending into each side margin may vary to produce multiple side gussets of different sizes in each side margin of the film. The unattached interlocking profile of the zipper is sealed by its flange section to an inner surface of the rear wall that is formed by the remaining portions of the side margins. A section of the gussets is sealed to the rear wall adjacent the interlocking elements of the zipper to form a border area below the zipper. The border area allows access to the interior of the bag only through the zipper area of the bag.
For a zipper without a slider, the tube proceeds in a bag-forming direction to a sealing section. The sealing section seals the unattached zipper profile by its flange to a face of each side gusset and to an inner surface of the rear wall of the tube in which the longitudinal borders of the rear wall are defined by the base of the side gussets. An opposite face of each side gusset is sealed to the inner surface of the rear wall as a border area to ensure that access to the contents of the formed reclosable bag is through the zipper only. The opposite face of each side gusset is sealed to the rear wall parallel to and below the sealing of the zipper to form the border area at and below the zipper.
The sealing section forms end stops on the zipper to prevent the zipper from separating and to prevent tearing into the bag at the ends of the zipper. The end stops also retain the slider on the zipper when the slider is used to open and close the bag. After the sealing operation, the sealing section separates the tube with an internal cutting device to form a reclosable bag and seals the film to form an end seal of a preceding reclosable bag. Another end seal may be formed as a part of a tamper-evident section of film adjacent the zipper of the reclosable bag.
In a second embodiment of the present invention, a first continuous length of bag-making film and a second continuous length of bag-making film are fed toward each other in a bag-forming direction from their respective supply rolls. The first length of film is fed to become the upper web and the second length of film is fed to become the lower web of the formed reclosable bag. First and second lengths of gusset material, each in the shape of an elongated tube, are positioned on the lower web transverse to the bag-forming direction. A first end of each length of gusset material is tack-sealed to the lower web.
A zipper is positioned on the lower web and on the first end of the lengths of gusset material and, if the zipper includes a slider, with the interlocking elements of the zipper adjacent the ends of the gusset material. A set of rollers advances the webs while flattening the gusset material. The flanges of the zipper are sealed to the upper and lower webs and over the first end of the lengths of gusset material.
In a first variation of the second embodiment of the present invention, the upper and lower webs are fed toward each other to provide film extensions on an opposite side of the zipper from the ends of the gusset material.
In a second variation of the second embodiment of the present invention, the tubular lengths of gusset material are fed between the flanges of the zipper. For the second embodiment and its first and second variations, the upper and lower webs, as well as the second end of the tubular lengths of gusset material, are sealed to form an end seal or a bottom seal of the reclosable bag.
The assembly of the webs and the zipper is advanced and transversely cut to the bag-forming direction and sealed to form a transverse seal at a leading edge. Also at the leading edge, the tubular length of gusset material is cut along a centerline of the length to form a side gusset while sealing the cut section of the gusset material to the webs as part of the transverse seal. The assembly of the webs, the zipper and the gusset material are advanced to a reclosable bag width in which a trailing edge is cut in the webs, in the zipper and in the gusset material to form the reclosable bag with a second side gusset at the trailing edge. Also at the trailing edge, the cut section of the gusset material is sealed to the webs as part of a transverse seal.
After the bag is filled with a consumer product, the open ends of the film extensions may be sealed to provide a tamper-evident feature which encloses the zipper. A weakness area is formed in the film extensions to tear away the film in order to access the zipper during an opening of the reclosable bag.
In a third variation of the second embodiment of the present invention, a semi-elliptical length of gusset material is inserted between the upper and lower webs and in a slit area of the first and second lengths of gusset material to form a bottom gusset of the reclosable bag.
BRIEF DESCRIPTION OF THE DRAWINGSFurther objects and advantages of the invention will become apparent from the following description and claims taken in conjunction with the accompanying drawings, in which:
Referring now to the drawings in detail in which like numerals indicate like elements throughout the several views, a continuous length of thermoplastic film 10 is shown in
As shown in
For a zipper 12 with the inserted slider 14, the retractable gusset-forming wheels 34, 35 form the side gussets 36, 38 adjacent the interlocking elements of the zipper to allow the slider to operate on the full length of the zipper. The size of gusset-forming wheels 34, 35 extending into each side margin may vary to produce different size gussets in each side margin. The flange of the unattached profile 18 is sealed to an inner surface of a rear wall 39 that is formed by the remaining portions of the side margins 20, 22.
For a zipper 12 without an inserted slider 14, the tube 26 proceeds in direction “A” to a sealing section 40 which seals the side gussets 36, 38 and the flange of unattached profile 18 of the zipper to the tube and to each other. As shown in the end view of an opened zipper 12 in
As shown in
The sealing section 40 of
If the sealing section 40 forms the end seal 70 shown on the reclosable bag of
In
In
A continuous length of zipper 124 is fed from a supply roll 126 to be positioned on the lower web 110 and on the first end 120 of the gusset material 112 if the zipper includes a slider 127. A set of rollers 128, 130 and 132 advance the webs 108, 110 in direction “B” while flattening the gusset material 112. The zipper 124 is sealed by its flanges to the upper and lower webs 108, 110 and over the first end 120 of the gusset material 112 by a sealing section 134. If desired, the sealing section 134 may also form end stops 135, 136 on the closure area 138 of the zipper 124. The sealing section 134 also seals the upper and lower webs 108, 110 to each other as well as to a second end 139 of the gusset material 112 to form the end seal 140.
The width of the zipper may also be wholly positioned on the gusset material 112 if the zipper does not include a slider. The rollers 128, 130 and 132 advance the upper and lower webs 108, 110 in direction “B” while flattening the gusset material 112 between the upper and lower webs. The zipper 124 is sealed to the webs 108, 110 and on the gusset material 112 by the sealing section 134. The sealing section 134 also seals the upper and lower webs 108, 110 to each other as well as to the second end 139 of the gusset material 112 to form the end seal 140.
The assembly of the webs 108, 110 and the zipper 124 is advanced between cross-sealers 141, 142 where the assembly is cut transversely to direction “B” and sealed to form a seal at the leading edge 143. The cross-sealers 141, 142 also cut the tubular length of gusset material 112 along a centerline of the length to form the side gusset 144 while sealing the cut section of the gusset material to the webs 108, 110 as part of the transverse seal 145. (See
In
In a first variation of the second embodiment shown in the continuous views of
As shown in the end view of
The assembly of the webs 108, 110, the gusset material 112 and the zipper 124 is advanced between the cross-sealers 141, 142 where the assembly is cut transversely to direction “B” and sealed to form a seal at the leading edge 143. The cross-sealers 141, 142 also cut the tubular length of gusset material 112 along a centerline of the length to form the side gusset 144 while sealing the cut section of the gusset material to the webs 108, 110 as part of the transverse seal 145. (See
In
In the continuing view of
When the side gussets 144, 148 are sealed to the zipper 124 as described in accordance with
In a second variation of the second embodiment shown in
As shown in
The assembly of the webs 108, 110 and the zipper 124 is advanced between the cross-sealers 141, 142 where the assembly is cut transversely to direction “B” and sealed to form a seal at the leading edge 143. The cross-sealers 141, 142 also cut the tubular length of gusset material 112 along a centerline of the length to form the side gusset 144 while sealing the cut section of the gusset material to the webs 108, 110 as part of the transverse seal 145. (See
As shown in
For filling the reclosable bag 147 and creating the tamper-evident feature 166, the reclosable bag proceeds to the sections of the apparatus shown in
In a third variation of the second embodiment shown in
The length of zipper 124 is fed from a supply roll 126 to be positioned on the lower web 110 and on the end 120 of the gusset material 112. The length of zipper 124 is positioned in the direction of and adjacent to an edge 150 of the lower web 110 to provide the film extension 152 between the zipper and the edge of the lower web. The rollers 128, 130 and 132 advance the webs 108, 110 in direction “B” while flattening the gusset material 112 and the gusset material 202.
The zipper 124 is sealed by one of its flanges to the lower web 110 and over the end 120 of the gusset material 112 by the sealing section 134. As shown in
As shown in
The assembly of the webs 108, 110, the bottom gusset 210 and the zipper 124 are advanced between the cross-sealers 141, 142 where the assembly is cut transversely to direction “B” and sealed to form a seal at the leading edge 143. The cross-sealers 141, 142 also cut the tubular length of gusset material 112 along a centerline of the length to form the side gusset 144 while sealing the cut section of the gusset material to the webs 108, 110 and the bottom gusset 210 as part of the transverse seal 145. (See
As shown in
For filling the reclosable bag 147 and creating the tamper-evident feature 166, the reclosable bag proceeds to the components of the apparatus shown in
Thus, the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
Claims
1-11. (canceled)
12. A reclosable plastic bag formed from a bag-making film and having a front wall and a rear wall, a first end and a second end and opposed sides; at least one side gusset in each said side; and a zipper having first and second interlockable profiles Joined by their interlocking elements extending across said bag between opposed sides, said first profile sealed to the front wall and said second profile sealed to a face of said at least one side gusset with the remaining portion of said second profile and an opposite face of said at least one side gusset sealed to the rear wall of said reclosable plastic bag.
13. The reclosable bag in accordance with claim 12, wherein said zipper is sealed to at least one side gusset on a bag interior side of the interlocking elements of said zipper.
14. The reclosable bag in accordance with claim 13, wherein said zipper further includes a slider for opening and closing said zipper.
15. The reclosable bag in accordance with claim 14, wherein said reclosable bag further includes a consumer product; and wherein the front and rear walls of bag-making film are sealed to each other at said first end adjacent said zipper with said bag-making film forming a tamper-evident section encompassing said zipper.
16. The reclosable bag in accordance with claim 15, wherein said tamper-evident section further includes a weakness area to assist in the removal of said section.
17. The reclosable bag in accordance with claim 16, wherein a bottom gusset forms the second end of said reclosable bag.
18. A reclosable plastic bag formed from a bag-making film and having a front wall and a rear wall, a first end and a second end and opposed sides; at least one side gusset in each said side; and a zipper having first and second interlockable profiles joined by their interlocking elements extending across said bag between opposed sides, a flange of said first profile sealed to the front wall and a face of said at least one side gusset and a flange of said second profile sealed to an opposite face of said at least one side gusset and to the rear wall of said reclosable plastic bag.
19. An apparatus for making a reclosable gusseted bag comprising: a first sealing section for sealing the first profile of a length of zipper having first and second interlockable profiles joined by their interlocking elements to a length of bag-making film having opposite longitudinal edges; a tube for folding said film so as to bring said longitudinal edges into an adjacent relationship to form a fin with side margins between said fin and the ends of said zipper; a second sealing section for forming a seal at said fin; at least one retractable wedge for indenting said sealed side margins toward said zipper ends to form at least one side gusset, a base of said at least one side gusset bordering a rear wall of said tube; a third sealing section for sealing the second profile of said zipper to a face of said at least one side gusset and to a surface of said rear wall facing the interior of said tube and for sealing an opposite face of said at least one side gusset in alignment with said zipper to said surface of said rear wall; a fourth sealing section for sealing across said tube at spaced intervals to form a first end seal of said reclosable bag; and a first cutter for cutting across said tube at spaced intervals to separate said tube as said reclosable bag.
20. The apparatus in accordance with claim 19 further including a consumer product feeder for filling said reclosable bag.
21. The apparatus in accordance with claim 20 wherein said apparatus further comprises a fifth sealing section for sealing on an opposite side of the zipper from said first end seal to form a second end seal as the top of said reclosable bag and a second cutter for forming a weakness area in said film between said second end seal and said at least one side gusset.
22. The apparatus in accordance with claim 19 wherein said retractable wedge is a rotating wheel in which the circumference of the wheel indents said side margins.
23. An apparatus for making a reclosable gusseted bag comprising: a first sealing section for sealing a section of a face of a first tubular length of gusset material and for sealing a section of a face of a second tubular length of gusset material at a bag width interval from said first length of gusset material to a lower web of bag-making film transverse to a bag-forming direction; a second sealing section for sealing a length of zipper in said bag-forming direction to an opposite face of each of said lengths of gusset material in alignment with the sections of the faces of said first and second lengths of gusset material and for sealing said length of zipper to said lower web and an upper web of bag-making film; a third sealing section for sealing said upper and lower webs together and to said lengths of gusset material to form a first end seal of said reclosable bag; a cutter for cutting said length of zipper, said lengths of gusset material and said webs transverse to said bag-forming direction at said bag-width interval and a fourth sealing section for sealing said face of said lengths of gusset material at the transverse cut of each to said lower web and for sealing said opposite face of said lengths of gusset material at the transverse cut of each to said upper web.
24. An apparatus for making a reclosable gusseted bag comprising: a first sealing section for sealing a section of a face of a first tubular length of gusset material and for sealing a section of a face of a second tubular length of gusset material at a bag width interval from said first length of gusset material to a lower web of bag-making film transverse to a bag-forming direction; a second sealing section for sealing a length of zipper in said bag-forming direction to an opposite face of each of said lengths of gusset material in alignment with the sections of the faces of said first and second lengths of gusset material and for sealing said length of zipper to said lower web; a third sealing section for sealing said upper and lower webs together and to said lengths of gusset material to form a first end seal of said reclosable bag; a cutter for cutting said length of zipper, said lengths of gusset material and said webs transverse to said bag-forming direction at said bag width interval; and a fourth sealing section for sealing said face of said lengths of gusset material at the transverse cut of each to said lower web and for sealing said opposite face of said lengths of gusset material at the transverse cut of each to said upper web; and a fifth sealing station for sealing said length of zipper to said upper web.
25. The apparatus in accordance with claim 24 wherein said apparatus further comprises a consumer product filling station for filling said reclosable bag.
26. The apparatus in accordance with claim 25, wherein said fifth sealing section seals said upper and lower webs together to form a second end seal on an opposite side of said zipper from said gusset material; and wherein said apparatus further comprises a second cutter for forming a weakness area in said upper and lower webs between said second end seal and said gusset material.
27. The apparatus in accordance with claim 24 wherein said apparatus further comprises a second cutter for slitting an end of each of said tubular length of gusset material; and wherein said third sealing section seals a semi-elliptical length of gusset material between said upper and lower webs and in the slit area of said tubular lengths of gusset material.
28. The apparatus in accordance with claim 24 wherein said apparatus further includes a wedge for separating a first flange from a second flange of said zipper; and wherein said second sealing section seals the first flange to said lower web and to said section of face of each of the first and second lengths of gusset material; and wherein said fifth sealing section seals the second flange to the upper web and an opposite face of each of the first and second lengths of tubular material.
Type: Application
Filed: Jan 17, 2006
Publication Date: Jun 1, 2006
Applicant:
Inventors: Steven Ausnit (New York, NY), Donald Crevier (Essex, IL)
Application Number: 11/333,425
International Classification: B65D 33/16 (20060101); B65B 9/06 (20060101); B65B 61/18 (20060101); B65D 33/14 (20060101); B65D 30/20 (20060101); B65B 61/20 (20060101); B65D 33/00 (20060101);