Multilayer pull string bag

Abstract

A web of multilayer material folded and sealed to create a gusseted bag comprising a step cut on the upper end of the bag, the bag further comprising a fold, where the fold enables the upper portion of the bag to be sealed to itself with adhesive, the fold running the width of the bag perpendicular to two side edges of the bag, the bag further comprising a pull string, where the pull string runs laterally from one side edge of the bag to the other, flush against the outer layer of the front panel, below the upper terminating edge of the inner layer of the back panel and above the upper terminating edges of the inner layer of the front panel, the outer layer of the front panel, and the outer layer of the back panel.

Description

BACKGROUND OF THE INVENTION

The invention disclosed herein is generally directed to a multilayered gusseted bag that may be opened by a consumer for access to the contents of the bag through the use of a pull string, whereby the pull string ruptures a portion of the bag to create the aforementioned access, as well as a method for manufacturing such a bag.

Multilayered gusseted bags are well known in the art, as are the use of a variety of pull string-type opening mechanisms for opening various types of bags. However, functional issues associated with a consumer using a pull string-type opening mechanism have been seen in the art where a step cut open end of an unfinished gusseted bag is folded over the pull string during manufacture of the bag.

In particular, the art lacks a quality multilayer bag with a pull string-type opening mechanism that is suitable for holding product of a fine particle size, such as flour, particularly during the physical rigors of transporting the product filled bags, that are cost-effective and easily produced.

The present invention aims to address these and other problems in the art.

SUMMARY OF THE INVENTION

The present invention includes a bag comprising a web of multilayer material folded and sealed to create a front panel, a back panel, and two gussets, wherein the front panel comprises an inner layer and an outer layer, and the back panel comprises an inner layer and an outer layer, each respective layer possessing an upper terminating edge, the bag further comprising a step cut on the upper end of the bag, the bag further comprising a fold, where the fold enables the upper portion of the bag to be sealed to itself, the fold running the width of the bag perpendicular to two side edges of the bag, whereby the upper terminating edge of the outer layer of the back panel covers the upper terminating edges of the inner layer of the back panel, the inner layer of the front panel, and the outer layer of the front panel, the bag further comprising adhesive, the adhesive residing on the outer layer of the front panel in an area bound by the fold, the two opposing side edges of the front panel, and the upper terminating edge of the outer layer of the back panel, the bag further comprising a pull string , where the pull string runs laterally from one side edge of the bag to the other, extending beyond at least one side edge of the bag, the pull string residing flush against the outer layer of the front panel, below the upper terminating edge of the inner layer of the back panel and above the upper terminating edges of the inner layer of the front panel, the outer layer of the front panel, and the outer layer of the back panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows perspective view of an embodiment of the finished multilayered bag of the present invention, with an embodiment of the pull string-type mechanism protruding from the bag. In this particular view, the bag is full and has been sealed at both ends.

FIG. 2 shows the upper end of an embodiment of the finished multilayered bag of the present invention, this view showing the front panel of the bag, with the pull string-type mechanism protruding from the bag.

FIG. 3 depicts a cross-sectional view of the bag of FIG. 2 along the line 3-3. FIG. 3 shows the spatial relationship between the various layers of this particular two layered bag embodiment, particularly with respect to the pull string.

FIG. 4 depicts a cross-sectional view as in FIG. 4, though the pull string has been removed from the bag to permit access to the contents of the bag, the entry path indicated by the arrow.

FIG. 5 depicts a view of the front of an unfinished bag of the present invention, prior to the insertion of the pull string or the adhesive. FIG. 5 aims to show the particular step cut pattern of a preferred embodiment.

FIG. 6, similar to FIG. 5, shows details of the step cut of an unfinished bag embodiment of the present invention, though FIG. 6 shows the details of the back panel from the inside of the unfinished bag, that is a view without the gussets or front panel.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the invention is a multilayered bag with a pull string-type mechanism that permits access to the inside of an otherwise sealed bag. One of skill in the art would appreciate the distinction between filling a bag with something with a large particle size, such as dog kibble, as opposed to filling a bag with a small particle size material, such as grain flour. Precise craftsmanship of the unfinished bag, as well as the placement of the pull string-type mechanism and adhesive, is required for a fine particle product. The present invention aims to provide a suitable solution to the problems associate with pull string-type mechanisms on multilayered bags that are intended to carry small particle size material.

As will be seen in the figures, one aspect of the invention is a multilayered bag. For the purposes of this disclosure, any means used to create a multilayered material, such as an adhesive between the layers, does not itself constitute a separate layer. For example two kraft paper layers adhered to one another through the use of a drip hot melt are only two layers, the hot melt not constituting a distinct layer.

At its simplest, multilayered means two layers of material adhered to one another prior to or during the manufacture of the bag. The present disclosure embraces multilayer configurations with three or more layers. In an embodiment, where two layers are present, both of the layers are kraft paper, the kraft paper layers having been colaminated together through the use of a hot melt, though any suitable adhesion substrate known in the art may be used to join the multiple layers. In another embodiment, the outer layer is clay coated paper, suitable for accepting printing, while the inner layer is kraft paper.

In making the bag, it is preferred that a web of multilayer material is folded to form the front panel, back panel, and two gussets such that the inner layer of the multilayer material faces the inside of the bag, and the outer layer of the multilayer material faces outwardly. The web is formed into a tube that is sealed along the length of the tube and then folded so as to form the panels and gussets. In an embodiment, any step cutting required of the bag is performed on the web of multilayer material prior to the formation of the bag. As described herein, a step cut is any cut on the various layers of the bag that is anything other than a flush cut.

Throughout the specification, reference is made to a pull string and a pull string-type mechanism. This should not be limited to, literally, common string. In any such instance, it should be understood to include any number of known strands suitable for use in the present invention, including but not limited to fibers, threads, or yarns that are plaited or twisted together for form a rope, cord, or the like. The pull string may additionally be a ribbon or scrim, which includes a woven strip or band of fine material. Additionally, the pull string may be a filament, including a monofilament, of plastic or other suitable material. These non limiting examples are meant for illustrative purposes, and any suitable length of material that functions to effectively breach the appropriate layers as detailed further herein is considered within the scope of equivalents of a pull string or pull string-type mechanism.

Throughout the specification, reference is made to a step cut. A step cut, as will be understood by one of ordinary skill in the art, is one or more cuts made to a bag, whereby the result of the one or more cuts is a bag with, at at least one end, one panel of a greater height than the other. In many instances, this includes a progressively lower cut on the two sides of the folded gusset, where the bag is a gusseted bag, moving from the higher panel to the lower panel. In the context of the present disclosure, a step cut refers at least to a back panel that is higher than the front panel, when the bag is held vertically with the upper end of the bag pointing upward. Examples of step cuts can be seen in the figures, particularly in FIGS. 5 and 6, as will be discussed further herein.

Referring now to the figures, FIG. 1 shows an elevated perspective view of an embodiment of the finished multilayered bag 100 of the present invention, with an embodiment of the pull string-type mechanism 102 protruding from the bag. In this particular view, the bag is full and has been sealed at both ends.

FIG. 2 shows the upper end 142 of an embodiment of the finished multilayered bag 100 of the present invention, this view showing the front panel 104 of the bag, with the pull string 102 protruding from the bag. In this view, a portion of the back panel 110 that has been folded at a fold 124 over the front panel 104 is visible.

In an embodiment, a partial destruction of the outer layer of the back panel 106 is present in the form of a linear series of perforations 108 on the front of the bag and generally in parallel alignment with the pull string 102 so as to permit easier access to the interior of the bag by a consumer. These perforations 108, when present, will run parallel to the pull string on one or both sides of the bag 100 in a length about equal to the length of the folded gusset from the side of the bag towards the inner cavity of the bag. The reason for this particular distance is to compensate for the extra amount of multilayered material that must be breached by the pull string to open the bag due to the location of the fold 124 and the presence of the gussets, as can be appreciated in the other figures, most notably FIGS. 5 and 6.

FIG. 3 depicts a cross-sectional view of the bag of FIG. 2 along the line 3-3. FIG. 3 shows the spatial relationship between the various layers of this particular two layered bag embodiment, particularly with respect to the pull string 102. In this embodiment, the front panel is comprised of an outer layer 116 and an inner layer 118, these layers having been at least partially colaminated together. Similarly, the back panel is comprised of an outer layer 122 and an inner layer 120 that have been similarly at least partially colaminated. These two panels and four layers have all been folded at a fold 124. The pull string 102 has been placed on the bag such that both the outer layer 116 and the inner layer 118 of the front panel cover the pull string 102 when the bag has been folded at the fold 124. However, after folding the bag at the fold 124, the upper terminating edge 138 of the inner layer 120 of the back panel terminates before the pull string 102, while the outer layer 122 of the back panel covers the top edges of each of the remaining layers. A layer of adhesive 112 has been placed on below the fold 124, past the pull string 102 down to the termination of the outer layer 122 of the back panel.

In a preferred embodiment, the pull string 102 is flush against the outer layer 116 of he front panel and is essentially surrounded by adhesive 112. In stating that the pull string be flush against the front panel, it is understood that adhesive may permeate in and around the pull string in an unpredictable manner and, by virtue of the volume of adhesive that might be used, portions of the pull string may not actually make direct contact with the front panel, though the pull string runs the length of the bag from side edge to side edge. Any embodiment where pull string and adhesive overlap and run in essentially the same linear distance from one side edge of the bag to the other side edge is considered within the scope of equivalents of the invention disclosed herein

FIG. 4 depicts a cross-sectional view as in FIG. 3, though the pull string has been removed from the bag 100 of FIG. 3 to permit access to the contents of the bag, the entry path indicated by the arrow 114. Due to the at least partial colamination of the respective layers of the front and back panels, and due to the presence of the adhesive layer, the portion of the back panel 110 above the location of the pull string may be unfolded along the fold 124. Although FIGS. 3 and 4 show an embodiment the bag of the present invention that is a two layered bag, additional layers may be used.

FIG. 5 depicts a view of the front of the upper end 142 of an unfinished bag of the present invention, prior to the insertion of the pull string or the adhesive. FIG. 5 aims to show the particular step cut pattern of a preferred embodiment. The front panel 104, of which the outer layer 116 is visible in this figure, has been cut to permit the gusset 106 to be adhered to the front panel with adhesive after the bag is folded over the fold 124. Additionally, the back panel 110, of which the inner layer 122 is visible in this figure, will be similarly adhered to the front panel 104 with adhesive, as can be seen further in FIG. 3.

FIG. 6, similar to FIG. 5, shows details of the step cut of an unfinished bag 100 embodiment of the present invention, though FIG. 6 shows the details of the back panel 110 from the inside of the unfinished bag, that is a view without the gussets or front panel. In this figure, both the outer layer 122 and inner layer 120 are visible. This figure illustrates the ideal placement of the pull string 102, which is determined by the distance 132 between the fold 124 and the upper terminating edge 138 of the inner layer of the back panel 120 between the gussets. The string may be placed at a location 126 that is that very nearly, but slightly greater than, the same distance 132 below the fold 124. In such an instance, in an embodiment, the pull string abuts and is substantially parallel to the upper terminating edge of the inner layer of the back panel.

In the preferred embodiment depicted in FIGS. 3 and 4, when the bag has been folded at the fold 124, both the upper terminating edge 134 of the outer layer of the front panel and the upper terminating edge 136 of the inner layer of the front panel pass over the pull string 102, whereas the upper terminating edge 138 of the inner layer of the back panel terminates prior to the location of the pull string. In this embodiment, the upper terminating edge 140 of the outer layer of the back panel passes over the upper terminating edges 134, 136, 138 of every other layer, as well as the pull string.

FIG. 6 additionally illustrates the ideal placement of the adhesive, which is applied at a substantially uniform height in a generally rectangular area across the bag, between the side edges of the bag 144. The distance 128 between the upper terminating edge 140 of the outer layer 122 of the back panel 110 to the fold 124 is the same distance 130 below the fold 124 that adhesive is applied across the outer layer 116 of the front panel 104, between the side edges of the bag 144.

In operation, a user would grasp one end of the pull string 102 and pull it from one side of the bag to the other, moving laterally across the upper end 142 of the bag 100, thereby breaching multiple layers of the material that comprise the bag, between the side edges of the bag 144. In so doing, access 114 to the inside of the bag and its contents is achieved.

Reviewing FIGS. 3 through 6 together, one can appreciate the value of the unique step cut of this invention. The cuts of the front panel 104 and the gussets 106 together prevent any of the inner layer 120 of the back panel 110 from receiving any of the adhesive 112 when the bag is folded. In this way, the removal of the pull string 102 perforates the outer layer 122 of the back panel 110 so that the portion of the outer layer 122 that has not received an adhesive bond to the front panel 104, as well as the inner later 120 of the back panel 110 may both be freely unfolded at the fold 124 to permit access to the contents of the bag 100 through the thus-created bag access 114. As such, the location of the pull string 126 relative to the inner layer 118 of the back panel 110 when folded is critical. It is preferable that the pull string 102 receive at least some of the adhesive 112 to prevent lateral movement of the string, while it is necessary at the same time the manufacturer prevents the inner layer 118 of the back panel 110 from receiving any adhesive 112.

The inventors discovered through testing that the location of the pull string 102 relative to the upper terminating edge 138 of the inner layer of the back panel, as seen throughout the figures, particularly in FIG. 6, is critical to the performance of the bag of the present invention, particularly in holding product of a fine particle size, such as flour, particularly during the physical rigors of transporting the product filled bags. Bags of the present invention, when filled with around thirty pounds of flour, were subjected to a series of tests to replicate the physical effects of a typical shipping regimen, and the bags passed the incline-impact shock test, a machine compression test, and a vibration test.

Where the pull string 120 was located at or above the upper terminating edge 138 of the inner layer of the back panel, in a parallel alignment that was closer to the fold 124 than the ideal placement indicated in FIG. 6 as reference character 126, the bags failed to open as desired and an imperfect access path 114, if any, was created.

While it is preferred that the pull string location 126 be just below the upper terminating edge 138 of the inner layer of the back panel, the pull string 120 may be placed on the bag in the area between the upper terminating edges 134, 136 of the layers of the front panel 104. In such an embodiment, the lack of adhesive or hot melt adhering the outer layer of the back panel 122 to the front panel 104 and the absence of the inner layer of the back panel 120 due to its termination 138 location, will still permit the creation of the access path 114 through the removal of the pull string 102 by a user, as seen in FIG. 4.

Therefore, in a particularly preferred embodiment, the present invention includes a bag 100 comprising a web of multilayer material folded and sealed to create a front panel 104, a back panel 110, and two gussets 106, wherein the front panel comprises an inner layer 118 and an outer layer 116, and the back panel comprises an inner layer 120 and an outer layer 122, each respective layer possessing an upper terminating edge, the bag further comprising a step cut on the upper end 142 of the bag, the bag further comprising a fold 124, where the fold enables the upper end of the bag to be sealed to itself, the fold running the width of the bag perpendicular to two side edges of the bag 144, whereby the upper terminating edge 140 of the outer layer of the back panel covers the upper terminating edges 134, 136, 138 of the inner layer of the back panel, the inner layer of the front panel, and the outer layer of the front panel, the bag further comprising adhesive 112, the adhesive residing on the outer layer of the front panel in an area 130 bound by the fold, the two opposing side edges of the front panel, and the upper terminating edge of the outer layer of the back panel, the bag further comprising a pull string 102, where the pull string runs laterally from one side edge 144 of the bag to the other, extending beyond at least one side edge of the bag, the pull string residing flush against the outer layer 116 of the front panel, below the upper terminating edge 138 of the inner layer of the back panel and above the upper terminating edges 134, 136, 140 of the inner layer of the front panel, the outer layer of the front panel, and the outer layer of the back panel.

The multilayer material, in a preferred embodiment, is a pair of colaminated kraft paper layers. In another preferred embodiment, the outer layers of the front panel and the back panel are the same and selected from a group consisting of clay coated paper and kraft paper, where the inner layers of the front panel and the back panel are kraft paper.

In an embodiment, the bag further comprises a linear series of perforations 108 on the outer layer 122 of the back panel, the perforations located on front of the bag and generally in parallel alignment with the pull string 102, and running parallel to the pull string one side of the bag in a length about equal to the length of the folded gusset from the side of the bag towards the inner cavity of the bag. In another embodiment, when present, the linear series of perforations are located on both sides of the bag.

It should be understood that the aforementioned embodiments are for exemplary purposes only and are merely illustrative of the many possible specific embodiments that can represent applications of the principles of the invention. Without departing from the spirit and scope of this invention, one of ordinary skill in the art can make various changes and modifications to the invention to adapt it to various usages and conditions, including those not specifically laid out herein. As such, those changes and modifications are properly, equitably, and intended to be, within the full range and scope of equivalents of the invention disclosed, described and claimed herein.

Claims

1. A bag comprising a web of multilayer material folded and sealed to create a front panel, a back panel, and two gussets, wherein the front panel comprises an inner layer and an outer layer, and the back panel comprises an inner layer and an outer layer, each respective layer possessing an upper terminating edge at an upper end of the bag,the bag further comprising a step cut on the upper end of the bag,the bag further comprising a fold, where the fold enables the upper end of the bag to be sealed to itself, the fold running the width of the bag perpendicular to two side edges of the bag, whereby the upper terminating edge of the outer layer of the back panel covers the upper terminating edges of the inner layer of the back panel, the inner layer of the front panel, and the outer layer of the front panel,the bag further comprising adhesive, the adhesive residing in a generally rectangular area on the outer layer of the front panel in an area bound by the fold, the two opposing side edges of the front panel, and the upper terminating edge of the outer layer of the back panel,the bag further comprising a pull string, where the pull string runs laterally from one side edge of the bag to the other side edge, extending beyond at least one side edge of the bag, the pull string residing flush against the outer layer of the front panel, below the upper terminating edge of the inner layer of the back panel and above the upper terminating edges of the inner layer of the front panel, the outer layer of the front panel, and the outer layer of the back panel.

2. The bag of claim 1, where multilayer material is a pair of colaminated kraft paper layers.

3. The bag of claim 1, where the outer layers of the front panel and the back panel are the same and selected from a group consisting of clay coated paper and kraft paper, where the inner layers of the front panel and the back panel are haft paper.

4. The bag of claim 1 further comprising a linear series of perforations on the outer layer of the back panel, the perforations located on front of the bag and generally in parallel alignment with the pull string, and running parallel to the pull string one side of the bag in a length about equal to the length of the folded gusset from the side of the bag towards the inner cavity of the bag.

5. The bag of claim 4 where the linear series of perforations are located on both sides of the bag.

6. The bag of claim 1, wherein the pull string abuts and is substantially parallel to the upper terminating edge of the inner layer of the back panel.