A TOP OPENING CLOSURE STRUCTURE FOR A PAPER BAG

Abstract

 The invention relates to a top opening closure structure for a paper bag, where said closure structure comprises a stiffening strip 6 running at the opposite edges of the confronting front and rear panels 1, 2. One of said stiffening strips 6 comprises closure elements extending from said stiffening strip 6 at both ends of said stiffening strip 6. At both ends of said stiffening strip 6 said closure elements comprise a closure strip 7 extending from said ends of said stiffening strip 6, said closure strip 7 comprising a glue layer 8 covered by the removable protective strip 9. A length of said glue layer 8 between said end of said stiffening strip 6 and a free end 10 of said closure strip 7 is shorter than a length of said closure strip 7 extending from said end of said stiffening strip 6.

Description

Technical Field

[0001] Present invention relates to the field of packaging, relates to the closable paper bags, and more specifically relates to single-use paper bags with an integrated closure used in fast food establishments. Present invention relates to a top opening closure structure for paper bag, where said paper bag is mainly intended for a fast-food packaging, but not limited to said purpose. Term "top opening" in the context of present invention is a fill end of the open mouth bag that is left open so the contents can be added into the bag before closing/sealing said bag.

Background Art

[0002] Retail sales establishments, fast-food and carryout restaurants and other retailers use various sizes, shapes and kinds of paper bags to assist the customer in containing, transporting, protecting and preserving purchased goods, food and other products purchased by the customer.

[0003] Additionally, gift bags of various sizes and types are in wide use for containing a gift for a gift-giving occasion and are frequently used in place of gift wrap paper.

[0004] European patent EP1315658B1 discloses a flexible container comprising a base portion including a bottom, side walls, defining an interior, the bottom defining a substantially flat planar surface when the container rests on it in use.

[0005] An upper panel comprises side panels corresponding with side walls of the base portion, the side panels having respective lower portions, that extend partially within the interior of the base portion to be located below an upper end of the base portion to be sealingly bonded thereto, and upper portions forming an opening providing access to the interior.

[0006] Two opposite side panels having upper ends provided with resealable closure members and said upper panel being constructed and arranged to define a substantially flat top surface in operatively closed configuration, said top surface rendering the container stackable with other like containers when the upper panel is closed and portions of the upper panel are folded.

[0007] The main objective of said solution is to make said containers stackable on each other. However for stackability of said container must have planar top surface formed on the top after closing said container and also said container must be filled with product capable of carrying load on top of it. Also, said closure structure includes closure members, where one is placed on an inner side of upper edge of a wall of said container and the other member is placed to an outer surface edge of an opposite wall of said container, making manufacturing of said container complicated. Further there is no easy way to open said container once it has been closed.

[0008] United States patent application US2012224794A1 discloses a sealable product containment bag structure, that includes generally rectangular shaped front and rear panels and pleated generally rectangular side panels connected to the front and rear panels. The front, rear and side panels forming at one end thereof an open top for the bag structure and being folded together at the other end thereof to form a closed bottom.

[0009] The adhesive layers are disposed in confronting relationship to each other on the inner surfaces of the front and rear panels near the open top end of the bag, and respectively covered by a protective strip, whereby, after the protective strips are removed, the adhesive layers adhere to each other and to the inner surfaces of the side panels when the side panels are folded inwardly in a closed condition for the bag structure.

[0010] Placement of adhesive layer onto an inner surface of un upper edge of the wall in this configuration has an additional problem, that when the mouth of the container is folded to be closed, the folded side wall parts are folded between opposing front and rear wall parts containing adhesive layer and said adhesive layer is not able reliably seal said container. Also, there is no easy way to open said container once it has been closed.

Summary of invention

[0011] Present invention relates to a top opening closure structure for a paper bag, where said bag comprising generally rectangular confronting front and rear panels, pleated generally rectangular side panels interconnecting said front and rear panels. Said front, rear and said side panels are defining a top opening for the bag structure at a first end of said panels. Also, said front, rear and side panels folded together at a second end of said panels form a closed bottom for the bag structure,

[0012] The top opening closure structure comprises a stiffening strip running at the opposite edges of the confronting front and rear panels. One of said stiffening strips comprises closure elements projecting (extending outward) from said stiffening strip at both ends of said stiffening strip.

[0013] At both ends of said stiffening strip said closure elements comprise a closure strip projecting (extending outward) from said ends of said stiffening strip, said closure strip comprising a glue layer covered by the removable protective strip.

[0014] A length of said glue layer between said end of said stiffening strip and a free end of said closure strip is shorter than a length of said closure strip projecting from said end of said stiffening strip.

[0015] Preferably length of said protective strip is longer than said glue layer. This means, that said protective strip has a free end, which can be used for pulling said protective strip off from the glue layer.

[0016] Preferably length of said protective strip is longer than said glue layer, but shorter than the length of said closure strip between said end of said stiffening strip and a free end of said closure strip. This means, that said closure strip has a free end, which can be used for pulling said closure strip with the glue layer after removal of the protective strip against the outer surface of the rear or front panel in order to seal the closure structure. Also, said free ends of closure strips can be used to open said closure structure, by pulling from said free ends of closure strips the part of the closure strips with glue layer off the outer surface of the outer surface of the front or rear panel.

[0017] In the preferred embodiment of the invention, the stiffening strips are placed on an outer surface at both opposite edges of the top opening of the paper bag.

[0018] In the preferred embodiment of the invention, said paper bag comprises handles projecting from the exterior surface of said front and rear panels.

[0019] A distance between the fixing points of the handles projecting from the outer surfaces of said confronting front and rear panels and said stiffening strips at the opposite edges of the confronting front and rear panels is at least one width of said stiffening strip.

[0020] In another preferred embodiment of the invention, the distance between the fixing points of the handles projecting from the outer surfaces of said confronting front and rear panels and said stiffening strips at the opposite edges of the confronting front and rear panels is at least three widths of said stiffening strip. Said distance may at least 100 mm.

[0021] According to another embodiment of the invention, said paper bag does not include handles.

Brief description of drawings

[0022] Present invention is described below with reference to the accompanying schematic drawings, in which:

Figure 1 depicts an axonometric view of a top opening closure structure for a paper bag in an open state;

Figure 2 depicts an axonometric view of a top opening closure structure for a paper bag in a state, where said closure structure is closed and edges with stiffening strips are in the process being folded over the longitudinal edges of said strips;

Figure 3 depicts an axonometric view of a top opening closure structure for a paper bag as viewed from the back panel in a state, where a free end and glue layer of both closure strips are not yet folded against the folded edge of the closure structure;

Figure 4 depicts an axonometric view according to Figure 3, where a free end and glue layer of both closure strips are folded against the folded edge of the closure structure;

Figure 5 depicts an axonometric view according to Figure 4, where the paper bag does not include handles;

Figure 6 depicts an enlarged view of a section of closure strip at the end of the stiffening strip as viewed from the top;

Figure 7 depicts an enlarged view of a section of closure strip at the end of the stiffening strip in a second embodiment of invention as viewed from the top;

Figure 8 depicts in a different stages A to F closing and opening of the closure structure as viewed from the top, where:

in stage A the top opening has not yet been closed,

in stage B confronting front and rear panels are pressed together and folding/rolling of the edges with stiffening strips is to be started,

in stage C folding of the edges with stiffening strips has been finished and protective strips being removed,

in stage D the closure strips with glue layer are being turned towards outer surface of the rear panel,

in stage E the glue layers are pressed against the outer surface of the rear panel and the closure structure is closed (bag is closed), and

in stage F is demonstration of opening of the closure structure by pulling from free ends of the closure strips.

Description of embodiments

[0023] For the sake of clarity of the drawings, the same details and elements are denoted by the same reference numerals in the various figures. Also for the sake of simplicity and clarity of the drawing, elements not necessary for an understanding of the invention, are not shown.

[0024] Figure 1 depicts a top opening closure structure for a paper bag. Said bag comprising generally rectangular confronting front and rear panels 1 and 2, pleated generally rectangular side panels 3 and 4 interconnecting said front and rear panels 1 and 2.

[0025] Said front panel 1, rear panel 2 and said side panels 3 and 4 are defining a top opening for the bag structure at a first end (upper end on Figure 1) of said panels 1, 2, 3 and 4.

[0026] At the bottom end of said front panel 1, rear panel 2 and said side panels 3 and 4, said panels are folded together to form a closed bottom 5 for the bag structure.

[0027] In the embodiment depicted on Figures 1, 2, 3 and 4, said paper bag includes handles 11 attached to the outer surfaces of front panel 1 and rear panel 2.

[0028] When the bag includes handles 11, distance H between the fixing points of the handles 11 projecting from the outer surfaces of said confronting front and rear panels 1 and 2 and said bottom edge of the stiffening strips 6 at the opposite edges of the confronting front and rear panels 1 and 2, must be at greater than the width h of said stiffening strip 6. Also, the upper parts of the handles 11, where user grabs said handles, must extend from the upper edged of bag after said top opening has twisted/folded shut so, that user's hand can fit between the folded edge and upper parts of the handles.

[0029] As a first step for closing a top opening of said bag, the inner surfaces of the edges of the front panel 1 and rear panel 2 with the stiffening strip 6 are moved against each other by folding side panels 3 and 4.

[0030] Next the upper edges with stiffening strips 6 of the front and rear panels 1 and 2 can be folded together over the longitudinal lower edge of one of the stiffening strips 6, as depicted on Figure 2.

[0031] Said distance H guarantees, that there is enough space between the fixing points of the handles 11 and lower edges of stiffening strips 6 to fold said edges at least once over the longitudinal lower edge of one of the stiffening strips 6 so, that the glue layers 8 on said closure strips 7 after the protective strips 9 (Figure 6) are removed, can be turned against a folded surface at the top of said folded upper edges of panels 1 and 2, as is showed with arrows on Figure 3.

[0032] For example, the width h of the stiffening strips 6 is about 10 to 25 mm, preferably about 15 mm, and the distance H between lower edged of stiffening strip 6 and the fixing points of the handles 11 is about 80 to 150 mm, preferably about 100 mm. The width h and distance H used depend on the size of the bag (mainly a width of the top opening) and stiffness of the stiffening strips 6 used.

[0033] Width h of the stiffening strips 6 determine the width of the folds at the upper part of the bag during the folding the top opening closed, thereby simplifying the procedure for closing the bag.

[0034] Figure 4 depicts a situation, where said glue layers 8 on closure strips 7 are already pressed against said folded upper edges of panels 1 and 2. The free ends 10 of said closure strips 7 are intended for opening of said closure structure. Said free ends 10 also facilitate opening and reclosing said bag, as bag can be opened without lacerating (tearing apart) said closure structure of bag.

[0035] As a comparison, on Figure 5 is shown bag without handles 11. Although handles are not used, the top part of the bag must have enough free height corresponding to the distance H after filling said bag with the goods, that said top opening can be closed exactly the same manner as described above.

[0036] The closure structure at the ends of the stiffening strip 6 is shown in more detail on Figure 6. It includes a stiffening strip 6 at the outer edge of the rear panel 2 and front panel 1 (not shown).

[0037] In the embodiment of Figure 6, the stiffening strip 6 at the edge of rear panel 2 comprises closure elements projecting from said stiffening strip 6 at both ends of said stiffening strip 6 - as said elements are identical at both ends of said stiffening strip 6, closure elements only at one end are depicted.

[0038] Said closure elements comprise a closure strip 7 projecting from said end of said stiffening strip 6.

[0039] As can be seen from the Figure 6, on the closure strip 7 is a glue layer 8 covered by the removable protective strip 9. Free end 10 of the closure strip 7 is not covered by a free end 12 of protective strip 9. The free end 12 of protective strip 9 is intended to facilitate removal of proactive strip 9 from the glue layer below it.

[0040] For sake of clarity, it should be mentioned, that the other end of the closure strips 7 are attached to the ends of the stiffening strips 6 - in the embodiments depicted on drawings, said ends are attached to the outer surface of said stiffening strips 6. But it is conceivable to attach said ends of closure strips 7 between stiffening strips 6 and outer surfaces of the upper edges of the front and rear panes 1, 2 (not shown on the drawings).

[0041] As can be seen from Figure 6, a length of the glue layer 8 between the end of the stiffening strip 6 and a free end 10 of said closure strip 7 is shorter than a length of said closure strip 7 projecting from said end of said stiffening strip 6. Said free end 10 enables user to pull said closure strip 7 open.

[0042] The second embodiment of Figure 7 corresponds to the embodiment on Figure 6, but all closure elements, such as glue layer 8 and protective strip 9 are placed on the opposite side of closure strip 7 when compared to embodiment on Figure 6.

[0043] Figure 8 depicts in a different stages A to F closing and opening of the closure structure as viewed from the top, where closure structure corresponds to the embodiment on Figure 6.

[0044] In order to close the bag, that is the top opening (mouth) of the bag, first bag is filled with goods and then edges with stiffening strips 6 of rear panel 2 and front panel 1 are pressed together, as shown on stage B.

[0045] On Figure 8 in stage B, edges of the front and rear panels 1, 2 with the stiffening strips 6 are folded in the direction of the front panel 1 over the lower edge of the stiffening strip 6 at the edge of the front panel 1.

[0046] Number of minimal number of folds necessary is determined by the position of glue layers 8 on the closure strips 7 - preferably said glue layers 8 should be able to be turned against the outer surface of rear panel 2 after the protective strips 9 are removed by pulling the free ends 12 of said protective strips 9 (stage C and D), as is depicted on Figure 8. Next, by pulling free end 10 of the closure strips 7, glue layers 8 are pressed against the outer surface of the rear panel (stage E).

[0047] Stage E depicts a situation, where the top opening closure structure is closed and sealed - it corresponds to the situation depicted in Figures 4 and 5.

[0048] As advantage of present invention, the closure structure of the invention can be safely opened without rupture of any element of said closure structure - opening of the closure structure is achieved by pulling from free ends 10 of the closure strips 7 as is shown in stage F in Figure 8.

[0049] It is obvious to the person skilled in the art that within the scope of attached claims the invention may have embodiments other than those described above.

Reference signs list

[0050] 

1 front panel

2 rear panel

3, 4 side panel

5 bottom

6 stiffening strip

7 closure strip

8 glue layer

9 protective strip

10 free end of said closure strip

11 handle

12 free end of protective strip

h width of said stiffening strip

H distance between the fixing points of the handles projecting from the outer surfaces of said confronting front and rear panels and said stiffening strips

Claims

1. A top opening closure structure for a paper bag, said bag comprising rectangular confronting front and rear panels (1, 2), pleated rectangular side panels (3, 4) interconnecting said front and rear panels (1, 2) and said front, rear and said side panels (1, 2, 3, 4) defining a top opening for the bag structure at a first end of said panels (1, 2, 3, 4), said front, rear and side panels (1, 2, 3, 4) folded together at a second end of said panels (1, 2, 3, 4) to form a closed bottom (5) for the bag structure, characterized in that the closure structure of the bag mouth comprises a stiffness strip (6) on the opposite edges of both the front panel (1) and the back panel (2), where one of said stiffening strips (6) comprises closure elements projecting from said stiffening strip (6) at both ends of said stiffening strip (6), where at both ends of said stiffening strip (6) said closure elements comprise a closure strip (7) projecting from said ends of said stiffening strip (6), said closure strip (7) comprising a glue layer (8) covered by the removable protective strip (9), where length of said glue layer (8) between said end of said stiffening strip (6) and a free end (10) of said closure strip (7) is shorter than a length of said closure strip (7) projecting from said end of said stiffening strip (6).

2. The top opening closure structure for a paper bag according to claim 1, characterized in that, a length of said protective strip (9) is longer than said glue layer (8).

3. The top opening closure structure for a paper bag according to claim 1, characterized in that, a length of said protective strip (9) is longer than said glue layer (8), but shorter than the length of said closure strip (7) between said end of said stiffening strip (6) and a free end of said closure strip (7).

4. The top opening closure structure for a paper bag according to any previous claim, characterized in that, said stiffening strips (6) are placed on an outer surface at both opposite edges of the top opening of the paper bag on the front panel (1) and the back panel (2).

5. The top opening closure structure for a paper bag according to any previous claim, characterized in that, said paper bag comprises handles (11) projecting from the exterior surface of said front and rear panels (1, 2).

6. The top opening closure structure for a paper bag according to any previous claim 1 to 5, characterized in that, distance (H) between the fixing points of the handles (11) projecting from the outer surfaces of said confronting front and rear panels (1, 2) and said stiffening strips (6) at the opposite edges of the confronting front and rear panels (1, 2) is at least one width (h) of said stiffening strip (6).

7. The top opening closure structure for a paper bag according to any previous claim 1 to 5, characterized in that, distance (H) between the fixing points of the handles (11) projecting from the outer surfaces of said confronting front and rear panels (1, 2) and said stiffening strips (6) at the opposite edges of the confronting front and rear panels (1, 2) is at least three widths (h) of said stiffening strip (6).

8. The top opening closure structure for a paper bag according to any previous claim 1 to 5, characterized in that, distance (H) between the fixing points of the handles (11) projecting from the outer surfaces of said confronting front and rear panels (1, 2) and said stiffening strips (6) at the opposite edges of the confronting front and rear panels (1, 2) is at least 100 mm.

Drawing