Tri-fold plastic bag roll

Abstract

A plastic bag is formed from a continuous extruded tube of polyethylene material. The tube is flattened and sealed across its width a intervals to form bag bottoms. The bags are joined to one another at a perforation line and folded in thirds lengthwise prior to being rolled into a compact roll, either with or without supporting core. After folding the bags may be chisel cut through the center of the perforation line to assist in dispensing of the bags. The chisel cut will extend through all layers of the bag when folded, resulting in three chisel cuts in the bag. The bags may be gusseted for part or as much as all of their width. The bags may also be corona treated and printed on their outer surfaces. The bags may be formed from partially recycled materials and various combinations of linear low density, medium and high density polyethylene.

Description

RELATED APPLICATION

The instant application is a Divisional application of U.S. patent application Ser. No. 10/847,690, filed May 18, 2004 and currently pending.

FIELD OF INVENTION

The invention pertains to plastic bags. More particularly, the invention relates to plastic bags designed for fresh produce that are dispensed from compact rolls and designed to be easily opened.

BACKGROUND OF THE INVENTION

Plastic bags have found wide use in grocery markets and retail applications for transporting produce groceries and various other items. To be most useful for consumers plastic bags should incorporate a number of features. These features relate to the ease of use of the bags with respect to opening them, placing goods inside, carrying them and dispensing them.

A variety of designs have been developed. U.S. Pat. No. 6,196,717, issued to Belias et al., is directed to a A method of forming a plurality of easy to open handle bags including the steps of providing a flattened tube of thermoplastic material oriented in a generally longitudinal direction. The flattened tube has a first longitudinal side edge and a second longitudinal side edge, a transverse lower heat seal, and a transverse upper heat seal. The tube also has first, second, and third sections. The second section is disposed between the first and third sections. The first section is joined to the second section along a generally longitudinal first fold line. The second section is joined to the third section along a generally longitudinal second fold line. The second section is cut along a generally transverse first cut line extending between the first and second fold lines. The first section is folded over the second section along the first fold line. The third section is folded over the previously folded-over first section along the second fold line such that the first, second, and third sections overlap one another.

The overlapped first, second, and third sections are cut along a generally longitudinal second cut line that intersects the first cut line, the first fold line, and the second side edge at one end and intersects the upper heat seal at the other end. The overlapped first, second, and third sections are then cut along a generally longitudinal third cut line that intersects the first cut line, the second fold line, and the first side edge at one end and intersects the upper heat seal at the other end.

U.S. Pat. No. 5,890,810, issued to Barlow, discloses an extruded plastics tube that is flattened with the lateral side portions folded to form inwardly extending gussets. Each gusseted side portion is then folded about a longitudinal fold line onto the medial portion between the side portions. The resultant layers are heat sealed to form the bottom of the bag.

U.S. Pat. No. 6,488,222, issued to West et al., describes A folded gusseted plastic bag has a first side gusset formed by first, second, and third longitudinal folds, a second side gusset formed by fourth, fifth, and sixth longitudinal folds, a seventh longitudinal fold being on a side of the bag containing the first, second, and third folds and forming a first folded bag flap, and an eighth longitudinal fold which is on a side of the bag containing the fourth, fifth, and sixth folds, the eighth fold forming a second folded bag flap. The folded gusseted bag also is folded into a total of at least eight contiguous plies. A roll of the folded, gusseted bags includes a continuous web of the folded, flattened bags joined along perforated severance lines. Preferably the perforated severance lines further comprise a centrally-located slit. The dispensing system utilizes the roll of folded-gusseted bags in combination with a dispenser comprising: (i) a support member for attachment to a support surface; (ii) a pair of guide channels carried by the support member for rotatably supporting the roll of plastic bags for rotation of the roll on the core; (iii) a tongue spaced apart from and carried by said support member in a predetermined position corresponding to the predetermined position of the slit in the tear line.

U.S. Pat. No. 6,379,292, issued to Simhaee, illustrates a continuous web of bags formed of a plurality of layers to be separated along a line of perforations that extends through all of the layers transverse of the web, in which at least one of the outermost layers is detached from the web at the separation line. Apparatus accomplishes this detachment in a moving web by engaging the outermost layer outer surface and exerting a force in a manner to produce the detachment from the separation line. Both the outermost upper and lower web layers can be detached at the separation line.

U.S. Pat. No. 5,967,663, issued to Vaquero et al., discloses a thermoplastic bag structure and method for making and packaging thermoplastic bags such that their tops are easily identified and the bags are easily opened. The method for producing these bags begins with cutting a flattened thermoplastic tube into two portions. At least one of the two portions is then collapsed to form a sheet of material having a pair of thermoplastic layers, a straight folded bottom edge and a pair of top edges, at least one of which has a skewed-cut. Bag side structures are formed in the sheet of material at about bag-width distances apart. The bags are then folded a predetermined number of times, in a direction transverse to the bag side structures, so that the skewed-cut top edge(s) of each of the bags remains exposed.

It is an objective of the present invention to provide plastic bags that can be easily stored on and dispensed from a variety of types of compact roll dispensers. It is a further objective to provide bags that can be formed into compact rolls on cores or without cores. It is a still further objective of the invention to provide bags that can be easily manufactured in gusseted or ungusseted form. Finally, it is an objective to provide roll mounted bags that are easily opened after dispensing and that are easily removed from the roll.

While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.

SUMMARY OF THE INVENTION

The present invention addresses all of the deficiencies of prior art folded plastic bag inventions and satisfies all of the objectives described above.

(1) A tri-fold plastic bag providing the desired features may be constructed from the following components. A continuous web of plastic bags formed from polyethylene material is provided. Each of the bags includes a front wall. The front wall has an inner surface, an outer surface, first and second side edges, a top edge and a bottom edge. A rear wall is provided. The rear wall has an inner surface, an outer surface, first and second side edges, a top edge and a bottom edge. The front wall is joined to the rear wall at respective first and second side edges thereof. The front wall is sealed to the rear wall adjacent respective bottom edges thereof. An open mouth is located at the top edges of the bag.

The front and rear walls of each of the bags are removably attached by a perforation line at the bottom edges to the top edges of a subsequent bag in the web. The web is folded twice parallel to a long axis of the bags to form a compact bag web approximately one third of a width of the bags. The folded web is rolled to form a compact bag roll.

(2) In a variant of the invention, a chisel cut is provided. The chisel cut extends through a center point of the perforation line of the folded web. When the compact roll is installed in a bag dispenser the chisel cut will engage a separating tongue when bags are pulled from the roll. When the bags are opened to their full width, three chisel cuts will appear at the perforation line.

(3) In a further variant, the compact web is rolled about a core.

(4) In still a further variant, the bags includes at least one side gusset, the side gusset extending inwardly from either of the first and second side edges of the front and rear walls.

(5) In yet a further variant, the side gusset extends inwardly from either of the first and second side edges of the front and rear walls for up to one third of the width of the bags.

(6) In another variant of the invention, the side gusset extends inwardly from either of the first and second side edges of the front and rear walls for up to one half of the width of the bags.

(7) In still another variant, the outer surface of at least one of the front wall and the rear wall of the bags is corona treated.

(8) In a further variant, the corona treatment of the outer surface of at least one of the front and rear walls of each of the bags is an amount sufficient to result in a surface tension on the wall of at least about 38 dynes/cm.

(9) In still a further variant, the outer surface of at least one of the front wall and the rear wall of the bags is printed.

(10) In yet a further variant, the first side edges are folded over the second side edges.

(11) In another variant of the invention, the first side edges are folded under the second side edges.

(12) In still another variant, the polyethylene material is formulated from about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate.

(13) In a further variant, the polyethylene material is formulated from about 10-20 wt. % recycled material, the recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene and 0-8 wt. % color concentrate.

(14) In still a further variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc.

(15) In yet a further variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes.

(16) In another variant of the invention, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc.

(17) In a final variant, the high density, medium molecular weight polyethylene has a melt index ranging from 0.10-0.30 gm/10 minutes.

An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of the preferred embodiment of the tri-fold plastic bag roll, illustrating a compact bag roll without core;

FIG. 1B is a perspective view of the bag of the FIG. 1A embodiment;

FIG. 2A is a perspective view of the preferred embodiment of the tri-fold plastic bag roll, illustrating a compact bag roll with core;

FIG. 2B is a perspective view of the bag of the FIG. 2A embodiment;

FIG. 3A is a perspective view of an alternative bag of the FIG. 1A embodiment, illustrating gussets approximately one third of the width of the bag;

FIG. 3B is a side elevational view of the FIG. 3A embodiment, illustrating the first side edges folded over the second side edges;

FIG. 4A is a perspective view of an alternative bag of the FIG. 1A embodiment, illustrating gussets approximately one half of the width of the bag;

FIG. 4B is a side elevational view of the FIG. 3A embodiment, illustrating the first side edges folded under the second side edges;

FIG. 5 is a perspective view of the bag of the FIG. 1A embodiment illustrating printing on the outer surface of the bag;

FIG. 6 is a side elevational view of the FIG. 5 embodiment, illustrating the first side edges folded over the second side edges; and

FIG. 7 is a side elevational view of the FIG. 5 embodiment, illustrating the first side edges folded under the second side edges;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(1) FIGS. 1A, 1B, 2A and 2B illustrate a tri-fold plastic bag roll 10 providing the desired features that may be constructed from the following components. A continuous web 15 of plastic bags 20 formed from polyethylene material 22 is provided. Each of the bags 20 includes a front wall 25. The front wall 25 has an inner surface (not shown), an outer surface 35, first 40 and second 45 side edges, a top edge 50 and a bottom edge 55. A rear wall 60 is provided. The rear wall 60 has an inner surface (not shown), an outer surface 70, first 75 and second 80 side edges, a top edge 85 and a bottom edge 90. The front wall 25 is joined to the rear wall 60 at respective first 40, 75 and second 45, 80 side edges thereof. The front wall 25 is sealed to the rear wall 60 adjacent respective bottom edges 55, 90 thereof. An open mouth 95 is located at the top edges 50, 85 of the bag 20.

The front 25 and rear 60 walls of each of the bags 20 are removably attached by a perforation line 100 at the bottom edges 55, 90 to the top edges 50, 85 of a subsequent bag 20 in the web 15. The web 15 is folded twice parallel to a long axis 105 of the bags 20 to form a compact bag web 110 approximately one third of a width 115 of the bags 20. The folded web 110 is rolled to form a compact bag roll 120.

(2) In a variant of the invention, as illustrated in FIGS. 2A and 2B, a chisel cut 125 is provided. The chisel cut 125 extends through a center point 130 of the perforation line 100 of the folded web 110. When the compact roll 120 is installed in a bag dispenser (not shown) the chisel cut 125 will engage a separating tongue (not shown) when bags 20 are pulled from the roll 120. When the bags 20 are opened to their full width 115, three chisel cuts 125 will appear at the perforation line 100.

(3) In a further variant, as illustrated in FIG. 2A the compact web 15 is rolled about a core 135.

(4) In still a further variant, as illustrated in FIGS. 3A, 3B, 4A and 4B, the bags 20 includes at least one side gusset 145, the side gusset 145 extending inwardly from either of the first 40, 75 and second 45, 80 side edges of the front 25 and rear 60 walls.

(5) In yet a further variant, as illustrated in FIGS. 3A and 3B, the side gusset 145 extends inwardly from either of the first 40, 75 and second 45, 80 side edges of the front 25 and rear 60 walls for up to one third of the width 115 of the bags 20.

(6) In another variant of the invention, as illustrated in FIGS. 4A and 4B, the side gusset 145 extends inwardly from either of the first 40, 75 and second 45, 80 side edges of the front 25 and rear 60 walls for to up one half of the width 115 of the bags 20.

(7) In still another variant, the outer surface 35, 70 of at least one of the front wall 25 and the rear wall 60 of the bags 20 is corona treated.

(8) In a further variant, the corona treatment of the outer surface 35, 70 of at least one of the front 25 and rear 60 walls of each of the bags 20 is an amount sufficient to result in a surface tension on the wall 25, 60 of at least about 38 dynes/cm.

(9) In still a further variant, as illustrated in FIG. 5, the outer surface 35, 70 of at least one of the front wall 25, and the rear wall 60 of the bags 20 is printed.

(10) In yet a further variant, as illustrated in FIG. 6, the first side edges 40, 75 are folded over the second side edges 45, 80.

(11) In another variant of the invention, as illustrated in FIG. 7, the first side edges 40, 75 are folded under the second side edges 45, 80.

(12) In still another variant, the polyethylene material 22 is formulated from about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate.

(13) In a further variant, the polyethylene material 22 is formulated from about 10-20 wt. % recycled material, the recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene and 0-8 wt. % color concentrate.

(14) In still a further variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc.

(15) In yet a further variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes.

(16) In another variant of the invention, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc.

(17) In still another variant, the high density, medium molecular weight polyethylene has a melt index ranging from 0.10-0.30 gm/10 minutes.

The tri-fold plastic bag roll 10 has been described with reference to particular embodiments. Other modifications and enhancements can be made without departing from the spirit and scope of the claims that follow.

Claims

1. A tri-fold plastic bag roll, comprising:

a continuous web of plastic bags formed from polyethylene material, each of said bags comprising: a front wall, said front wall having an inner surface, an outer surface, first and second side edges, a top edge and a bottom edge; a rear wall, said rear wall having an inner surface, an outer surface, first and second side edges, a top edge and a bottom edge; said front wall being joined to said rear wall at respective first and second side edges thereof; said front wall being sealed to said rear wall adjacent respective bottom edges thereof; an open mouth disposed at said top edges;

said front and rear walls of each of said bags being removably attached by a perforation line at said bottom edges to said top edges of a subsequent, bag in said web;

said web being folded twice parallel to a long axis of said bags to form a compact bag web approximately one third of a width of said bags; and

said folded web being rolled to form a compact bag roll.

2. The tri-fold plastic bag roll, as described in claim 1, further comprising:

a chisel cut, said chisel cut extending through a center point of said perforation line of said folded web; and

whereby, when said compact roll is installed in a bag dispenser said chisel cut will engage a separating tongue when bags are pulled from said roll, and when said bags are opened to said width, three chisel cuts will appear at said perforation line.

3. The tri-fold plastic bag roll, as described in claim 1, wherein said compact web is rolled about a core.

4. The tri-fold plastic bag roll, as described in claim 1, further comprising at least one side gusset, said side gusset extending inwardly from either of said first and second side edges of said front and rear walls.

5. The tri-fold plastic bag roll, as described in claim 4, wherein said side gusset extends inwardly from either of said first and second side edges of said front and rear walls for up to one third of said width of said bags.

6. The tri-fold plastic bag roll, as described in claim 4, wherein said side gusset extends inwardly from either of said first and second side edges of said front and rear walls for up to one half of said width of said bags.

7. The tri-fold plastic bag roll, as described in claim 1, wherein said outer surface of at least one of said front wall and said rear wall of said bags is corona treated.

8. The tri-fold plastic bag roll, as described in claim 7, wherein said corona treatment of said outer surface of at least one of said front and rear walls of each of said bags is an amount sufficient to result in a surface tension on said wall of at least about 38 dynes/cm.

9. The tri-fold plastic bag roll, as described in claim 7, wherein said outer surface of at least one of said front wall and said rear wall of said bags is printed.

10. The tri-fold plastic bag roll, as described in claim 1, wherein said first side edges are folded over said second side edges.

11. The tri-fold plastic bag roll, as described in claim 1, wherein said first side edges are folded under said second side edges.

12. The tri-fold plastic bag roll, as described in claim 1, wherein said polyethylene material is formulated from about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate.

13. The tri-fold plastic bag roll, as described in claim 1, wherein said polyethylene material is formulated from about 10-20 wt. % recycled material, the recycled material comprising about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate.

14. The tri-fold plastic bag roll, as described in claim 12, wherein 10-15 wt. % of said linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc.

15. The tri-fold plastic bag roll, as described in claim 12, wherein 10-15 wt. % of said linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes.

16. The tri-fold plastic bag roll, as described in claim 12, wherein said high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc.

17. The tri-fold plastic bag roll, as described in claim 12, wherein said high density, medium molecular weight polyethylene has a melt index ranging from 0.10-0.30 gm/10 minutes.