BACKGROUND OF THE INVENTION
1. Field of the Invention
Various embodiments of the present invention described herein generally relate to packaging articles, particularly heat-shrinkable, easy opening packaging articles for packaging food products.
2. Description of Related Art
Flexible packaging articles made from plastic film are commonly used for the packaging of a variety of products. In particular, food products (e.g., meat) are often vacuum packed in heat-shrinkable, plastic packaging articles. In order to keep packed food products fresh and enhance shelf life, it is important for these packaging articles to possess moisture and oxygen barrier properties, as well as high impact strength, high seal strength, and high puncture resistance. However, packaging articles having these properties are typically tough and difficult to open.
To make tough packaging articles of this type easier to open, recent art suggests providing one or more tear initiators near an edge of a packaging article for initiating a manual tear that can be propagated to open the packaging article and allow a product to be readily removed therefrom. In particular, U.S. Publication No. 2009/0116768 (herein “the '768 publication”) suggests providing grip-assist holes adjacent a tear initiator to assist a user with gripping the packaging article, initiating a tear at the tear initiator, and propagating the tear to open the packaging article. In some cases, these grip-assist holes may be formed by cutting a hole in the packaging article and removing the resulting piece of plastic film to form each grip-assist hole. However, as recognized in the '768 publication, this process produces small, loose pieces of film that may lodge inside the packaging article during manufacturing of the packaging article. To prevent production of these loose pieces of film, the '768 publication suggests cutting a partial hole in the packaging article's film that results in an opening and leaves a hanging chad connected to the packaging article. In this configuration, the aforementioned loose pieces of film are less likely to be produced during manufacturing of the packaging article.
However, when a user opens a packaging article having grip-assisters of this type, the user typically inserts an index finger through a grip-assist hole, pinches the index finger with a thumb, and pulls away from the tear initiator. During this opening process, the user may inadvertently pinch the grip-assister's hanging chad between the index finger and thumb and tear the hanging chad off of the packaging article during opening. Hanging chads inadvertently removed from the packaging article in this way may easily fall into the packaging article as the user is opening the article.
For sellers of products that must not be contaminated with loose plastic pieces, such as meats and other food products, it is important that loose pieces of plastic are not produced during manufacturing of the packaging article or during end use of the packaging particle (e.g., a user opening the article). Accordingly, there is a need in the art for a flexible, easy opening packaging article that can be manufactured and used without the risk of loose pieces of plastic becoming lodged within the packaging article.
BRIEF SUMMARY OF THE INVENTION
Various embodiments of the present invention are directed to a flexible packaging article. According to various embodiments, the flexible packaging article comprises a plastic film formed into an enclosure for receiving a product and defining at least one openable portion, at least one seal closing the openable portion of the enclosure, at least one article skirt comprising a portion of plastic film extending outwardly from the seal and opposite the enclosure, at least one tear initiator defined on the skirt, the at least one tear initiator being configured for initiating one or more manually-propagated tears capable of being propagated through the seal to open at least the openable portion of the enclosure, and one or more grip assisters defined on the skirt and configured for assisting grip of the plastic film during manual tearing. The one or more grip assisters comprise at least one cut in the skirt defining: an opening, a first hanging chad on a first side of the cut, and a second hanging chad on a second side of the cut. The first hanging chad comprises at least a pair of projected portions and a recessed portion in between the pair of projected portions, and the second hanging chad comprises at least one projected portion aligned with the first hanging chad's recessed portion.
Various other embodiments of the present invention are directed to a flexible packaging article comprising a plastic film formed into an enclosure for receiving a product and defining at least one openable portion, at least one seal closing the openable portion of the enclosure, at least one article skirt comprising plastic film extending outwardly from the seal and opposite the enclosure, at least one tear initiator defined on the skirt, the at least one tear initiator being configured for initiating one or more manually-propagated tears capable of being propagated through the seal to open at least the openable portion of the enclosure, and one or more grip assisters defined on the skirt and configured for assisting grip of the plastic film during manual tearing, the one or more grip assisters comprising at least one curvilinear cut in the skirt defining an opening in the skirt and at least one hanging chad. The curvilinear cut includes first and second ends spaced apart from one another and the hanging chad comprises a base edge defined between the first and second ends of the curvilinear cut, and the lateral distance between the first and second ends of the curvilinear cut defining the hanging chad's base width. The hanging chad extends outwardly from its base edge in a direction away from the at least one tear initiator, and the distance between the hanging chad's base edge and its outermost edge defining the hanging chad's length. The hanging chad further comprises a first outer lobe having a substantially convex rounded edge and a second outer lobe having a substantially convex rounded edge. The first and second outer lobes are defined on lateral sides of the hanging chad and extending laterally past the first and second ends of the curvilinear cut, the lateral distance between the widest points of the first and second outer lobes defining the hanging chad's full width. The ratio of the hanging chad's base width to its full width is between 0.881:1 and 0.75:1.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 shows a front perspective view of an end-seal bag according to one embodiment of the present invention;
FIG. 2 shows a rear elevation view of the end-seal bag of FIG. 1 according to one embodiment of the present invention;
FIG. 3 shows a top plan view of the end-seal bag of FIG. 1 according to one embodiment of the present invention;
FIGS. 4A and 4B show top plan views of a grip assister according to one embodiment of the present invention;
FIG. 5 shows a front perspective view of the grip assister of FIGS. 4A and 4B according to one embodiment of the present invention;
FIG. 6 shows a top plan view of a partially opened end-seal bag with a product disposed therein according to one embodiment of the present invention;
FIG. 7A shows a side-seal bag according to one embodiment of the present invention;
FIG. 7B shows a U-seal bag according to one embodiment of the present invention;
FIG. 7C shows an L-seal bag according to one embodiment of the present invention;
FIG. 7D shows a back-seamed bag with a fin seal according to one embodiment of the present invention;
FIG. 7E shows a back-seamed bag with a lap seal according to one embodiment of the present invention;
FIG. 8A shows a top plan view of a grip assister according to one embodiment of the present invention; and
FIG. 8B shows a top plan view of another grip assister according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present inventions will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
Various embodiments of the present invention are generally directed to an easy opening packaging article, such as an end-seal bag or the like, having a tear initiator and one or more grip assisters. According to various embodiments, the tear initiator and grip assisters are configured to assist a user in opening the packaging article. In particular, the grip assisters are configured to reduce the likelihood that a loose piece of plastic is generated during the opening process, and to reduce the likelihood that undesired tears in the packaging article are generated during the opening process.
End-Seal Bag Having Grip Assisters
FIGS. 1 and 2 illustrate a lay-flat end-seal bag 10 formed from seamless plastic film tubing according to one embodiment of the present invention. As shown in FIGS. 1 and 2, the end-seal bag's seamless plastic film forms a first lay-flat side 12, a second lay-flat side 14, a first folded side edge 16, a second folded side edge 18, a bottom edge 20, and a top edge 30. The bottom end of the end-seal bag 10 is unsealed and forms an bag opening 22 dimensioned for receiving a product to be packaged within the end-seal bag 10 (e.g., a large cut of meat). The top end of the end-seal bag 10 includes an end seal 31, which extends across the width of the of the end-seal bag 10.
In the illustrated embodiment, the end seal 31 is a heat seal sealing the bag's first lay-flat side 12 to the bag's second lay-flat side 14. The end seal 31 can be generated by various methods, such as impulse sealing, melt-bead sealing, thermal sealing, ultrasonic sealing, hot air sealing, hot wire sealing, infrared radiation sealing, ultraviolet radiation sealing, electron beam sealing, or other methods known in the art. Although the end seal 31 extends along an arcuate path across the width of the bag 10 in the embodiment of FIG. 1, the end seal 31 may extend straight across the bag 10 or along a path having a different profile according to various other embodiments. Typically, the end seal 31 is made as part of the manufacturing process at a bag-making factory, rather than at the site where the bag 10 is used to package a product. As such, the end seal 31 may commonly be referred to as a “factory seal.”
The interior volume of the end-seal bag 10 between the bag's end seal 31 and bottom edge 20 comprises an enclosure 19 for receiving a product to be packaged within the end-seal bag 10. As described in greater detail below, once a product is placed within the bag's enclosure 19 (e.g., via the bag opening 22), a packers seal may be applied proximate the bag's bottom edge 20 and the bag 10 may be shrunk around the product to seal the product within the bag 10.
The end-seal bag 10 also includes a skirt 32, which generally comprises the portion of the bag's plastic film outward of the end seal 31 (e.g., the excess film on the non-product side of the end seal 31, between the end seal 31 and top edge 30). As shown in FIG. 1, the skirt 32 extends across the full width of the end-seal bag 10 and is contiguous with the end seal 31. However, in various other embodiments, the skirt 32 may comprise one or more portions of plastic film extending outwardly from the end seal 31, each portion extending along less than the full width of the end seal 31. The various features described herein as being defined on the skirt 32 may be defined on such skirt portions. In addition, the general shape and profile of the skirt 32 may be altered by changing the profile of the bag's end seal 31 and/or top edge 30.
In the illustrated embodiment, the portion of the bag's first lay-flat side 12 and second lay-flat side 14 defining the skirt 32 are sealed together with a pair of perimeter seals 34 positioned proximate the bag's top edge 30. In the illustrated embodiment, the perimeter seals 34 are heat seals and may be generated using any of the methods referenced above in relation to the end seal 31. As shown in FIG. 1, the perimeter seals 34 are generally configured to keep the skirt portions of the bag's first lay-flat side 12 and second lay-flat side 14 laid substantially flat against one another.
The skirt 32 also defines a tear initiator 50 and a pair of grip assisters 100. As described in greater detail herein, the tear initiator 50 and grip assisters 100 are, together, configured to enable a user to manually initiate and manually propagate a tear along the end-seal bag 10 in order to open the bag 10 and remove a product contained therein. FIG. 3 shows a top plan view of the end-seal bag 10. As shown in FIG. 3, the tear initiator 50 comprises a plurality of longitudinally aligned slits 52 cut through the skirt 32. According to other embodiments, the tear initiator 50 may comprise a single slit cut through the skirt 32. As used herein, the term “cut” refers to penetration through the plastic film or shearing through the film (e.g., with a shearing or cutting instrument). Unless specified otherwise, a “cut” in a portion of the end-seal bag 10 refers to a cut through both lay-flat sides 12, 14 of the bag 10. Accordingly, the slits 52 comprising the tear initiator 50 are defined in both the first lay-flat side 12 of the skirt 32 and the second lay-flat side 14 of the skirt 32.
In the illustrated embodiment of FIG. 3, the tear initiator 50 is oriented generally perpendicular to the nearest point on the end seal 31 and in a generally longitudinal direction with respect to the end-seal bag 10. In particular, the end-seal bag 10 is configured such that a tear initiated via the tear initiator 50 will tend to propagate in a longitudinal direction with respect to the end-seal bag 10. However, according to various embodiments, the tear initiator 50 may be oriented in other directions and the end-seal bag 10 may be configured such that a tear initiated via the tear initiator 50 will tend to propagate in other desired directions.
With respect to the bag's plastic film, the tear initiator 50 in FIG. 3 is oriented in a machine direction. As used herein, the phrase “machine direction” generally refers to the direction in which the plastic film emerged from its manufacturing die, which corresponds with the direction the plastic extrudate is forwarded during the film production process. However, as used herein, the phrase “machine direction” includes not only the direction along the plastic film that corresponds with the direction the film traveled as it passed over idler rollers in the film production process, it also includes directions that deviate up to 44 degrees from the direction the film traveled as it passed over idler rollers in the production process. In addition, as used herein, the phrase “transverse direction” refers to a direction perpendicular to the machine direction. The transverse direction also includes directions that deviate up to 44 degrees from the direction the film traveled as it passed over idler rollers in the production process. As described in greater detail below, various embodiments of the tear initiator 50 may be oriented in the machine direction or the transverse direction with respect to a bag's plastic film depending on the bag's dimensions and the bag's type (e.g., end-seal, side-seal, pouch). Furthermore, preferred films to be used to make the packaging article of the invention include films in accordance with U.S. Ser. No. 12/313,396, to Huerta et al, entitled “Easy Opening Packaging Article Made from Heat-Shrinkable Film Exhibiting Directional Tear” and now published as US 2009/0116768, the entirety of which is hereby incorporated by reference thereto. Preferred methods of making such films are also disclosed in U.S. Ser. No. 12/313,396.
Referring back to the illustrated embodiment of FIG. 3, the grip assisters 100 are defined on either side of the tear initiator 50 and are positioned just below the perimeter seals 34. According to various embodiments, each grip assister 100 is defined by a curvilinear cut in the skirt 32. FIGS. 4A and 4B provide a more detailed illustration of one of the grip assisters 100 according to one embodiment. As shown in FIG. 4A, the curvilinear cut 102 has a first end 104 and a second end 106. The cut 102 forms a curvilinear path between its ends 104, 106 that results in the formation of a first hanging chad 200 and a second hanging chad 300. As used herein, the term “hanging chad” refers to a portion of material (e.g., plastic film) that is not completely separated from its respective article (e.g., the end-seal bag 10). Indeed, in the illustrated embodiment, no fully separated pieces of film are produced by the cut 102 and the hanging chads 200, 300 remain attached to the end-seal bag 10. In reference to FIGS. 4A and 4B, the terms “width,” “length,” “outward,” “inward,” and other like terms are used to describe the chads 200, 300 in relation to the grip assister 100 itself and are not intended to indicate the orientation of the grip assister 100 with respect to other features of the end-seal bag 10. Indeed, a description of the grip assister's orientation and positioning with respect to features of the end-seal bag 10 is provided herein in relation to FIGS. 1, 3, and 5.
In the illustrated embodiment, the first hanging chad 200 extends outwardly from a first base edge 202, which is defined between the ends 104, 106 of the curvilinear cut 102. As described in more detail herein, the first hanging chad's base edge 202 connects the first hanging chad to the skirt 32 from which it “hangs.” The first hanging chad 200 generally includes a pair of projected portions comprising a first outer lobe 204 and a second outer lobe 206. As shown in FIGS. 4A and 4B, the first outer lobe 204 includes a substantially convex rounded edge 208 and extends laterally to a widest point 212 and outwardly to an outermost point 216. Likewise, the second outer lobe 206 includes a substantially convex rounded edge 210 and extends laterally to a widest point 214 and outwardly to an outermost point 218. In addition, the first hanging chad 200 includes a recessed portion 220 positioned between the outer lobes 204, 206 and defined by a substantially concave rounded edge 222. As shown in FIG. 4B, the rounded edge 222 has an innermost point 219 (e.g., the point along the rounded edge 222 nearest to the first hanging chad's base edge 202). Each of the rounded edges 208, 210, 222 is defined by a curved portion of the curvilinear cut 102.
In the illustrated embodiment, the second hanging chad 300 extends outwardly from a second base edge 302 in a direction opposite that of the first hanging chad 200. As shown in FIG. 4A, the second base edge 302 is defined between the outermost points 216, 218 of the first hanging chad 200. As described in more detail herein, the second hanging chad's base edge 302 connects the second hanging chad 300 to the skirt 32 from which it “hangs.” The second hanging chad 300 generally includes a projected portion comprising a medial lobe 304. As shown in FIG. 4A, the second hanging chad's medial lobe 304 includes a substantially convex rounded edge 308 that corresponds to the concave rounded edge 222 of the first hanging chad 200. In other words, the second hanging chad's convex rounded edge 308 is defined opposite the first hanging chad's concave rounded edge 222 along the same portion of the curvilinear cut 102. Accordingly, as shown in FIG. 4B, the medial lobe's outermost point 319 corresponds to the innermost point 219 of the first hanging chad's rounded edge 222.
FIG. 4B also illustrates various dimensions of the grip assister 100. In the illustrated embodiment, the first hanging chad 200 has a base width W1 generally defined by the lateral distance between the ends 104, 106 of the curvilinear cut 102. As will be appreciated from FIGS. 4A and 4B, the base width W1 of the first hanging chad 200 corresponds to the length of the first hanging chad's base edge 202. According to various embodiments, the first hanging chad's base width W1 can be between 0.69 inches and 0.88 inches. For example, in one embodiment, the first hanging chad's base width W1 is 0.83 inches. In addition, the first hanging chad 200 has a full width W2 generally defined by the lateral distance between the widest points 212, 214 of the first hanging chad's outer lobes 204, 206. According to various embodiments, the first hanging chad's full width W2 can be between 0.75 inches and 1.0 inches. For example, in one embodiment, first hanging chad's full width W2 is 1.0 inches.
As shown in FIGS. 4A and 4B, the rounded edges 208, 210 of the outer lobes curve inwardly such that the ends 104, 106 of the curvilinear cut 102 are positioned inward from the outer lobe's widest points 212, 214. In particular, the first outer lobe's rounded edge 208 has a radius of curvature R1 and the second outer lobe's rounded edge 210 has a radius of curvature R2. According to various embodiments, the radii R1 and R2 can be between 0.14 inches and 0.2 inches. In certain embodiments, the radii R1 and R2 are the same. For example, in one embodiment, the radii R1 and R2 are each 0.19 inches.
As shown in FIG. 4B, the inward curvature of the rounded edges 208, 210 results in the cut's first end 104 being positioned a lateral distance D1 inward from the widest point 212 of the first outer lobe 204, while the cut's second end 106 is positioned a lateral distance D2 inward from the widest point 214 of the second outer lobe 206. According to various embodiments, the distances D1 and D2 can be between 0.06 inches and 0.15 inches. In certain embodiments, the distances D1 and D2 are the same. For example, in one embodiment, the distances D1 and D2 are each 0.09 inches.
As described in greater detail below, it is generally desirable for the first hanging chad's base width W1 to be nearly as wide as the first hanging chad's outer width W2, as increasing the chad's base width W1 can improve chad's resistance to being torn off of the skirt 32 by a user. However, it is also desirable for the distances D1, D2 to not be too small, as positioning the ends 104, 106 of the cut 102 away from the chad's widest edges 212, 214 can improve the grip assister's resistance to generating an undesired tear in the skirt 32 when it is used to open the bag 10. Accordingly, the ratio of the first hanging chad's base width W1 to its full width W2 can be between 0.881:1 and 0.75:1.
In addition, the first outer lobe 204 has a length L1 defined by the distance between the first outer lobe's outermost point 216 and the base edge 202. Likewise, the second outer lobe 206 has a length L2 defined by the distance between the second outer lobe's outermost point 218 and the base edge 202. According to various embodiments, the greater of these two lengths L1, L2 defines the “length” of the first hanging chad 200. According to various embodiments, the lengths L1 and L2 can be between 0.3 inches and 0.38 inches. In certain embodiments, the lengths L1 and L2 are the same. For example, in one embodiment, the first outer lobe's length L1 and the second outer lobe's length L2 are 0.34 inches. In such an embodiment, the “length” of the first hanging chad 200 would be 0.34 inches as L1 and L2 are the same.
As shown in FIG. 4B, the second hanging chad 300 has a width W3 generally defined by the lateral distance between the outermost points 216, 218 of the first hanging chad's lobes 204, 206. As will be appreciated from FIGS. 4A and 4B, the second hanging chad's width W3 corresponds to the length of the second hanging chad's base edge 302. According to various embodiments, the second hanging chad's width W3 can be between 0.12 inches to 0.75 inches. For example, in one embodiment, the second hanging chad's width W3 is 0.62 inches.
Furthermore, the second hanging chad 300 has a length L3 defined by the distance between the medial lobe's outermost point 319 and the base edge 302. According to various embodiments, the second hanging chad's length L3 can be between 0.12 inches and 0.20 inches. For example, in one embodiment, the second hanging chad's length L3 is 0.19 inches.
In addition, the rounded edge 308 of the medial lobe 304 has a radius of curvature R3. As will be appreciated from FIGS. 4A and 4B, the rounded edge 222 of the first hanging chad's recessed portion 220 will have the same radius of curvature R3 as it is defined by the same portion of the curvilinear cut 102. According to various embodiments, the radius R3 can be between 0.12 inches and 0.20 inches. For example, in one embodiment, the radius R3 is 0.19 inches. In certain embodiments of the grip assister 100, the second hanging chad's radius of curvature R3 may be equivalent to its length L3 and equivalent to the radii R1 and R2.
In the illustrated embodiment of FIGS. 4A and 4B, the curvilinear cut 102 defining the grip assister 100 comprises a single, continuous cut through the skirt 32. However, in other embodiments, the cut 102 may comprise a series of perforations aligned in the shape of the cut 102 shown in FIGS. 4A and 4B. In addition, in the illustrated embodiment of FIGS. 1-5, the cut 102 extends through both lay-flat sides 12, 14 of the skirt 32. As such, each grip assister 100 will be understood to comprise a first grip assister defined on the first lay-flat side 12 of the skirt 32, and a second grip assister defined on the second lay-flat side 14 of the skirt 32. According to various embodiments, these first and second grip assisters are aligned and, effectively, function together as a single grip assister 100.
As will be appreciated from FIG. 3, the grip assisters 100 are oriented on the skirt 32 such that each grip assister's first hanging chad 200 extends away from the tear initiator 50 in a direction generally perpendicular to the tear initiator 50, while each grip assister's second hanging chad 300 extends toward the tear initiator 50 in a direction generally perpendicular to the tear initiator 50. Likewise, the base edge 202 of each grip assister 100 is generally parallel to the tear initiator 50. As described in greater detail below, this orientation ensures that when a user pulls the grip assisters 100 away from the tear initiator 50, the force of the user's finger is applied against the base edge 302 and towards the second hanging chad 300.
Opening the End-Seal Bag Using the Tear Initiator & Grip Assisters
According to various embodiments, the tear initiator 50 and grip assisters 100 are configured to enable a user to manually initiate and manually propagate a tear along the end-seal bag 10 in order to open the bag 10 and remove a product contained therein. As described above, each of the grip assisters 100 includes a curvilinear cut 102 in the skirt 32. FIG. 5 shows one of the grip assisters 100 with its hanging chads 200, 300 pushed upward and extending away from the surface of the skirt 32. As shown in FIG. 5, the curvilinear cut 102 defines an opening 110 in the skirt 32, which exists between the first hanging chad 200 and second hanging chad 300.
Each grip assister 100 is configured such that its opening 110 is large enough for an adult finger to fit through. When an adult finger is inserted through the opening 110, the hanging chads 200, 300 are generally moved to the position shown in FIG. 5. As shown in FIG. 5, the first hanging chad 200 bends upward about its base edge 202, while the second hanging chad 300 bends upward about its base edge 302. As discussed earlier herein, in the illustrated embodiment, each grip assister 100 comprises a first grip assister defined on the first lay-flat side 12 of the skirt 32, and a second grip assister defined on the second lay-flat side 14 of the skirt 32. As shown in FIG. 5, both the first lay-flat side 12 and second lay-flat side 14 of the grip assister's chads 200, 300 are substantially aligned. As will be appreciated from FIG. 5, the curvilinear shape of the grip assister's cut 102 results in a larger opening 110 than a straight, linear cut would provide. This makes it easier for a user to insert a finger through the grip assister 100.
FIG. 6 shows the end-seal bag 10 with a product 120 (e.g., a cut of meat) sealed therein. In particular, the product 120 has been disposed within the bag's enclosure 19 (e.g., via the opening 22 at the bag's bottom edge 20 shown in FIG. 1). In addition, a packer's seal 122 (e.g., a heat seal) has been applied proximate the bag's bottom edge 20 to fully seal the product 120 within the bag 10. Furthermore, the bag 10 has been heat-shrunk around the product 120. To open the end-seal bag 10 shown in FIG. 6, a user may insert at least one finger through each of the grip assisters 100 and pull the grip assisters 100 away from one another (e.g., by pulling each grip assister 100 in a direction away from the tear initiator 50 and in a direction generally perpendicular to the tear initiator 50). This action applies a force to the tear initiator's longitudinally aligned slits 52 that initiates a tear in the direction of the longitudinally aligned slits 52. To propagate the tear along the end-seal bag 10, a user can continue pulling the grip assisters 100 away from one another. This causes the tear to propagate through the bag's end seal 31 and continue along the bag 10.
As shown in FIG. 6, a tear 130 has been initiated and propagated along a portion of the bag 10. Referring back to FIG. 3, the tear initiator's slits 52 are generally aligned in the bag's longitudinal direction in the illustrated embodiment. As such, in FIG. 6, the tear 130 has propagated longitudinally along the length the bag 10. In the illustrated embodiment, this longitudinal direction is also the machine direction of the bag's plastic film. In addition, as the tear initiator 50 and grip assisters 100 are defined on both lay-flat sides 12, 14 of the bag 10, the tear 130 has initiated and propagated along both lay-flat sides 12, 14. Once the bag 10 is sufficiently opened or torn entirely in half, the user can easily remove the product 120 from the bag 10.
During the aforementioned opening process, each of the user's fingers will apply a force to the skirt 32 proximate the base edge 302 of a respective grip assister 100 (shown in FIG. 5). In particular, the user's finger will pull the base edge 302 in a direction away from the first hanging chad 200. Referring back to FIG. 5, the force generated by this action can result in stress concentration points 61, 62 generated near the widest points of the curvilinear cut 102 on the skirt 32 (e.g., the points along the edge of the cut 102 on the skirt 32 corresponding to the widest points 212, 214 of the first and second outer lobes 204, 206). In order for the grip assisters 100 to be most effective, it is important to prevent the skirt 32 from tearing in response to these stress concentrations as the bag is opened, as this can result in a stress gradient. If the stress gradient is such that the stress at the ends 104, 106 of the cut 102 is greater than the tear propagation limit of the material, then the skirt 32 will tear.
To prevent such tearing, as described above in relation to FIGS. 4A and 4B, the ends 104, 106 of the curvilinear cut 102 are positioned distances D1, D2 inward from the lobes' widest points 212, 214. As a result, the stress concentrations resulting from the force applied by a user's finger when opening the bag 10 are concentrated away from the ends of the cuts and, instead, on the cut's rounded edges (e.g., the edges of the cut corresponding to the rounded edges 208, 210 of the first hanging chad 200). In certain embodiments, these stress concentration points remain in this position at least until the tear propagated via the tear initiator extends through the seal. By configuring the shape of the grip assister 100 in this way, the grip assister's resistance to tearing on the skirt 32 is improved and the grip assisters 100 are prevented from being torn out of the end-seal bag 10.
In addition, during the aforementioned opening process, a user will typically insert an index finger through the grip assister's opening 110 and pinch the index finger with a thumb in order to grip the grip assister 100. In the illustrated embodiment of FIGS. 1-6, the second hanging chad's recessed portion 220 reduces the likelihood that the second hanging chad 200 will be inadvertently pinched between a user's fingers by reducing the length of the chad 200 in the area where that is most likely to occur. By reducing the likelihood that the chad 200 will be pinched between the user's fingers, the likelihood that the second hanging chad 200 will be inadvertently torn off is also reduced.
Furthermore, even where the second hanging chad 200 is inadvertently pinched and pulled away from its base edge 202, the chad 200 is dimensioned to resist being torn off of the skirt 32. For example, the second hanging chad's base width W1 is relatively wide and provides a greater contact area between the chad 200 and skirt 32 than a chad having a narrower base width. By increasing the contact area between the second hanging chad 200 and the skirt 32, the chad 200 is made more resistant to being torn off of the skirt 32 when it is inadvertently pulled. As a result, the end-seal bag 10 having the grip assisters 100 can be opened without generating loose plastic pieces that may fall into the bag 10 and contaminate the product 120.
According to various embodiments, the grip assisters 100 are also capable of being used with a machine configured for opening packaging articles. For example, certain machines may include components (e.g., rods) that are inserted through the grip assisters 100 and pulled away from one another in order to automatically open the end-seal bag 10. Accordingly, it will be understood that the tear initiator 50 and grip assisters 100 can be used by an automated machine to initiate and propagate a tear in the end-seal bag 10.
Further Embodiments
As will be appreciated from the description herein, the end-seal bag 10 shown and described in FIGS. 1-6 represents only one embodiment of the present invention. For example, the tear initiator 50 and grip assisters 100 described in relation to the end-seal bag 10 may be provided on various types of bags and in various orientations. For example, FIG. 7A illustrates the tear initiator 50 and grip assisters 100 provided on a side-seal bag 710. In the illustrated embodiment of FIG. 7A, the tear initiator 50 and grip assisters 100 are positioned on a skirt defined on the sides of the bag 710 and are configured to initiate a tear in the machine direction of the bag's plastic film.
As further examples, FIG. 7B illustrates a U-seal bag 720 and FIG. 7C illustrates an L-seal bag 730. In both bags 720, 730, the tear initiator 50 and grip assisters 100 may be defined on a skirt located on the side of the bags 720, 730 or on an end of the bags 720, 730. In addition, in both bags 720, 730, the tear initiator 50 and grip assisters 100 may be configured to initiate a tear in either the machine direction or the transverse direction of the plastic film. As yet another example, FIG. 7D illustrates a back-seamed bag 740 having a fin seal. In the illustrated embodiment, the tear initiator 50 and grip assisters 100 can be provided on a skirt proximate the bag's fin seal or bottom seal. As yet another example, FIG. 7E illustrates a back-seamed bag 750 having a lap seal. In the illustrated embodiment, the tear initiator 50 and grip assisters 100 can be provided on the skirt proximate the bag's lap seal or bottom seal. In particular, a tear generated from a tear initiator 50 positioned on a skirt extending outwardly from the back-seamed bag's 740 fin seal, or the back-seamed bag's 750 flap seal, could propagate from the skirt, through the fin seal/lap seal, and thereafter propagate as two tears in opposite directions around the bag 740 or 750. In addition, as will be appreciated from the description herein, a tear initiator 50 and pair of grip assisters 100 may be provided at more than one location on one or more skirts of a particular bag to enable a user to tear the bag open in more than direction.
Furthermore, as will be appreciated from the description herein, the grip assister 100 shown and described in FIGS. 1-6 represents only one embodiment of a grip assister suitable for use with the end-seal bag 10. For example, in certain embodiments, a grip assister may define a single hanging chad not having a recessed portion. FIG. 8A shows a grip assister 500 according to one such embodiment. In the illustrated embodiment, the grip assister 500 is defined by a curvilinear cut 502 forming a single hanging chad 501. The curvilinear cut has ends 504, 506 forming a base edge 507 therebetween. The hanging chad 501 includes a pair of outer lobes 510, 512 and a substantially linear medial edge 520 joining the outer lobes 510, 512. In addition, the outer lobes 510, 512 each include a convex rounded edge 514, 516. As will be appreciated from FIG. 8A, the ends 504, 506 of the curvilinear cut 502 are positioned inward of the widest points of the outer lobes 510, 512.
In various embodiments, the hanging chad 501 can have the same base width, full width, and length dimensions described above in relation to the first hanging chad 200. As such, the grip assister 500 retains many of the advantageous properties of the grip assister 100. For example, as the ends 504,506 of the curvilinear cut 502 defining the hanging chad 501 are positioned inward of the chad's widest edges, the curvilinear cut 502 will be resistant to generating a tear in the skirt 32. Likewise, as the chad 501 has a wide base edge 507 and relatively short length, the chad 501 will be less likely to be inadvertently pinched by a user and, even if it is, will be resistant to tearing off of the skirt 32.
FIG. 8B shows a grip assister 600 according to another embodiment. In the illustrated embodiment, the grip assister 600 is defined by a curvilinear cut 602 forming a single hanging chad 601. The curvilinear cut has ends 604, 606 forming a base edge 607 therebetween. The hanging chad 601 includes a pair of outer lobes 610, 612 and a convex, rounded medial edge 620 joining the outer lobes 610, 612. In addition, the outer lobes 610, 612 each include a convex rounded edge 614, 616. As will be appreciated from FIG. 8B, the dimensions of the hanging chad 601 are substantially similar to those of the hanging chad 501, with the exception of the chad 601's curved medial edge 620. As such, the grip assister 600 would also retain many of the advantageous properties of the grip assister 100 for the reasons discussed in relation to the grip assister 500.
The dimensions of the various grip assisters described herein (e.g., the grip assisters 100, 500, 600) represent certain embodiments of the present invention. As will be appreciated from the description herein, the grip assisters provided in other dimensions and configured to perform as described herein are within the scope of the present invention.
CONCLUSION
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Patent Application
20130077899
