Flexible package having improved gripper ridges and methods thereof

A gripper ridge for use on a flexible package includes first and second walls normal to the flexible package with first and second extended ends and an end surface between the first and second extended ends. The end surface and first extended end are arranged to provide enhanced gripping friction perceptible to touch. The length of the first wall is greater than the length of the second wall, such that the end surface is angled. In one implementation, the end surface and first extended end form a rounded surface therebetween. One embodiment includes a flexible package with one or more gripper ridges attached to the interior of the flexible package. In other embodiments, one or more gripper ridges are attached to the exterior of the flexible package. A die for making a gripper ridge and methods for making a gripper ridge are also described.

FIELD OF THE INVENTION 
The present invention relates generally to flexible package arrangements. 
More specifically, the present invention relates to gripper ridges for 
reclosable arrangements for flexible bags. 
BACKGROUND OF THE INVENTION 
Flexible packages sometimes use reclosable closure arrangements. One type 
of reclosable closure arrangement includes a zipper-type closure. Other 
types of reclosable-type closure arrangements are also sometimes used. 
One typical reclosable zipper includes male and female closures extending 
along the length of the zipper. The closures are interlocked by properly 
aligning the male and female closures and pressing the closures together 
along the entire length of the zipper. To open the closure arrangement, 
the user grasps the bag panel sections in order to pull the interlocking 
profiles apart. 
The closures are often attached to bags made from a polymeric material. 
Polymeric bags are prone to become slippery if wet or greasy. If the bags 
are wet or greasy, or if the user of the bag has wet or greasy hands, 
manipulation of the bag by the user may be difficult. In particular, it is 
sometimes difficult to grip or hold onto the bag in order to perform the 
opening and closing operation of the closure arrangement. 
Another problem sometimes encountered is that the bag walls between the 
closure arrangement and the top of the bag opening cling together when 
moist. This sometimes presents further difficulty in operating the closure 
arrangement. 
Therefore, a need exists for improving the ease of performing the opening 
operations of a reclosable-type closure arrangement. 
SUMMARY OF THE INVENTION 
One aspect of the present invention is directed to a gripper ridge for use 
on a bag. The gripper ridge comprises a first wall normal to the bag and 
includes a first extended end. The first wall has a first length extending 
between the bag and first extended end. A second wall is normal to the bag 
and includes a second extended end. The second wall has a second length 
extending between the bag and the second extended end. An end surface 
extends between the first extended end and the second extended end. The 
end surface and first extended end are arranged to provide enhanced 
gripping friction perceptible to touch. 
In the preferred arrangements, the first length is greater than the second 
length. 
In certain implementations, the end surface and first extended end form a 
rounded surface therebetween, skewed toward the inside of the bag. 
In another aspect, the invention is directed to a reclosable bag. The 
reclosable bag comprises an outer enclosure including a surrounding wall 
portion, a product-supporting bottom, and a reclosable mouth opposing the 
product-supporting bottom. The wall portion includes an interior surface 
oriented toward an interior of the bag and an opposite exterior surface. A 
closure arrangement is integral with or secured to the wall portion and 
adjacent to the mouth to allow an opening and closing of the mouth. A 
first gripper ridge is integral with or secured to the interior surface of 
the wall portion. The first gripper ridge is constructed and arranged to 
include a first gripping end perceptible to touch as oriented toward the 
closure arrangement. 
In one implementation, the first gripper ridge includes first and second 
opposite walls each being oriented substantially normal to the bag wall 
portion. The first wall includes a first extended end, and the second wall 
includes a second extended end. The first gripper ridge includes an end 
surface between the first and second extended ends. The end surface and 
first extended end are arranged to form the first gripping end. 
In the preferred embodiment, the first wall is closer to the closure 
arrangement than the second wall. The first wall includes a first length 
from the wall portion to the first extended end, and the second wall 
includes a second length from the wall portion to the second extended end. 
The first length is greater than the second length. 
In one embodiment, the closure arrangement includes a zipper-type closure. 
Certain embodiments include the surrounding wall having first and second 
opposed panel sections joined along a pair of sealed edges. Each of the 
first and second panel sections include an interior surface and an 
exterior surface. The first gripper ridge is secured to the interior 
surface of the first panel section and is located between the mouth and 
the closure arrangement. A second gripper ridge is secured to the interior 
surface of the second panel section. In other embodiments, the second 
gripper ridge is secured to the exterior surface of the second panel 
section. In yet other embodiments, the second gripper ridge is secured to 
the exterior surface of the first panel section. The second gripper ridge 
includes a second gripping end perceptible to touch as oriented toward the 
zipper closure arrangement. 
In other implementations, the bag further includes a third gripper ridge. 
The third gripper ridge is secured to the interior surface of the first 
panel section and adjacent to the first gripper ridge. In other 
arrangements, the third gripper ridge is secured to the exterior surface 
of the first panel section. In still other arrangements, the third gripper 
ridge is secured to the exterior surface of the second panel section. 
In another embodiment, the bag further includes a fourth gripper ridge 
secured to the interior surface of the second panel section. The fourth 
gripper ridge is secured to the exterior surface of the second panel 
section. 
In certain implementations, the gripper ridges and closure arrangements are 
included in first and second strips which are secured to the first and 
second walls of the bag in the bag making process. The gripper ridge or 
ridges are located near the top of the bag between the bag mouth and the 
closure arrangement. 
In another arrangement, the bag further includes a second strip. The second 
strip is arranged to secure a second gripper ridge to the second panel 
section. A third gripper ridge is secured to the first strip, and a fourth 
gripper ridge is secured to the second strip. 
In another aspect of the invention, a die includes an inlet and an outlet 
used in making a gripper-ridge profile. The outlet has a profile including 
a base, a first edge, a second edge, and a third edge extending between 
the first and second edges. The first edge extends normal to the base and 
has a first length; and the second edge extends normal to the base and has 
a second length less than the first length. 
In one arrangement, the first length is from about 1.5 to 2.5 times a 
thickness of the base. The second length is from about 1.0 to 2.0 times a 
thickness of the base. The third edge is from about 1.0 to 1.5 times a 
thickness of the base. 
In one implementation, a fourth edge is opposite to the third edge. The 
fourth edge includes a peak to reduce an amount of material in a final 
extrusion. 
In another aspect of the present invention, a method for making a gripper 
ridge comprises providing a die having an inlet and an outlet. The outlet 
includes a profile including a base, a first edge, a second edge, and a 
third edge extending between the first and second edges. The first edge 
extends normal to the base and has a first length; and the second edge 
extends normal to the base and has a second length less than the first 
length. A molten thermoplastic material is pumped through the inlet. A 
gripper ridge is extruded through the outlet profile. 
In one embodiment, the providing step includes providing the outlet profile 
with a fourth edge opposite to the third edge, the fourth edge including a 
raised peak. The extruding step includes extruding a gripper ridge 
including a reduced amount of molten material in a region of the fourth 
edge. 
The above summary of the present invention is not intended to describe each 
disclosed embodiment of the present invention. This is the purpose of the 
figures and the detailed description which follow.

DESCRIPTION 0F THE VARIOUS EMBODIMENTS 
Flexible package arrangements come in a variety of shapes and sizes and 
serve various purposes. One type of flexible package arrangement includes 
a bag having a reclosable-type closure. There are instances when it is 
useful to have structure to help the user grasp the bag in order to open 
the reclosable-type closure. Gripper ridges positioned adjacent to and 
between the closure arrangement and the bag opening are used to provide 
the user with enhanced structure and material to improve his or her grasp 
on the bag and help open the closure arrangement. As described in detail 
below, one aspect of the present invention relates to improving the 
gripping friction of a gripper ridge, while also reducing the amount of 
material necessary in order to make a gripper ridge. 
One type of flexible package arrangement, a bag, is illustrated in FIG. 1 
generally at 10. In one embodiment, bag 10 is made from a film of 
polymeric material, and is sealed together at first side seal 12, and 
second seal 14. Bag 10 includes a bottom 16 and a top 17, at an opposite 
end thereof. A mouth 18 is opposite to bottom 16 and adjacent to top 17, 
and provides access to the bag interior. Mouth 18 is configured to be 
openable and closable through a closure arrangement, shown generally at 
20. Closure arrangement 20, in this particular embodiment, includes a 
zipper 22. The closure arrangement in other embodiments includes other 
types of closure arrangements. Positioned between zipper 22 and top of bag 
17 are first and second gripper ridges 24, 26. 
As illustrated in FIG. 2, each of the gripper ridges is located between the 
top of the bag 17 and the zipper 22. In this embodiment, first and second 
gripper ridges 24, 26 are located on an interior surface of a first wall 
28 of the bag, and third and fourth gripper ridges 30, 32 are located on a 
second wall 34 of the bag. The zipper 22, in the embodiment illustrated in 
FIG. 2, has a male profile 37 on first bag wall 28, and a female profile 
38 on second wall 34 of the bag. First, second, third, and fourth gripper 
ridges.24, 26, 30, 32 extend the length from first side seal 12 to second 
side seal 14 of bag 10. The gripper ridges provide the user with structure 
to grasp to aid in opening and closing of the zipper 22. While two gripper 
ridges per bag wall are illustrated, other embodiments include more or 
fewer gripper ridges. Further, other implementations include gripper 
ridges positioned on the exterior surface of the bag walls. 
FIG. 3 illustrates a cross-sectional view of first gripper ridge 24. Each 
of the other illustrated gripper ridges 26, 30, and 32 are constructed 
similarly to first gripper ridge 24. Gripper ridge 24 includes a first 
wall 40 normal to the bag wall 28. First wall 40 includes a base end 42 
integral with first bag wall 28, and an extended end 44, or free end, at 
an end opposite to base end 42. Gripper ridge 24 includes a second wall 46 
normal to first bag wall 28. Second wall 46 includes a base end 48 and an 
extended end 50, or free end. Base end 48 is integral with bag wall 28. An 
end surface 52 extends between extended end 44 of first wall 40 and 
extended end 50 of second wall 46. 
End surface 52 and first extended end 44 are constructed and arranged 
relative to one another to provide enhanced gripping friction perceptible 
to touch. More specific to the embodiment illustrated in FIG. 3, end 
surface 52 and first extended end 44 are arranged to form a gripping end 
54 to help the user grasp the bag and manipulate the closure arrangement. 
The illustrated gripping end 54 represents both sharp points, as well as 
rounded surfaces. In the embodiment illustrated in FIG. 3, the point is a 
rounded surface which is made by a die profile having a radius of about 
0.009 inch. In other embodiments, the rounded surface of the die profile 
has a radius of anywhere from about 0.005 to about 0.10 inch. It is 
advantageous to arrange the gripper ridge such that the gripping end 54 is 
oriented closer to the closure arrangement than to the top of the bag. In 
this manner, the shape of the gripper ridge points the user toward the 
closure arrangement. 
First wall 40 has a length which is greater than second wall 46. First wall 
40 is arranged relative to bag wall 28 to be closer to zipper 22 than 
second wall 46 is to zipper 22. This results in end surface 52 being 
angled toward the closure arrangement 20 in a way such that the user's 
fingers are directed downward towards the closure arrangement 20. Gripping 
friction is enhanced when the user applies force away from the closure 
arrangement 20. 
FIG. 4 illustrates a second embodiment of a closure arrangement including 
gripper ridges and an exemplary reclosable zipper. Other types of 
reclosable closures are also usable with the gripper ridges of FIG. 4. In 
this particular illustrated embodiment, first, second, third, and fourth 
gripper ridges 56, 58, 60, 62 are extruded as part of first and second 
strips 64, 66. First strip 64 is extruded to include first and second 
gripper ridges 56, 58 as well as female profile 68 of a zipper-type 
closure arrangement. Second strip 66 is extruded to include third gripper 
ridge 60, fourth gripper ridge 62, and male profile 70 of a zipper-type 
closure arrangement. First and second strips 64, 66 are secured to a pair 
of bag walls 71, 72, by suitable methods such as heat sealing or by an 
adhesive, for example. While four gripper ridges are illustrated in the 
FIG. 4 embodiment, other embodiments include more gripper ridges, while 
other embodiments include fewer gripper ridges. 
A third embodiment of a closure arrangement is illustrated in FIG. 5. In 
this illustrated embodiment, a first strip 73 includes first and second 
gripper ridges 74, 76, and an exemplary female closure profile 78. A 
second strip 83 includes a third gripper ridge 82, a fourth gripper ridge 
84, and an exemplary male profile 86 for a zipper closure. First strip 73 
is secured to a first bag wall 88 by a suitable method, such as heat 
sealing, or by an appropriate adhesive. Similarly, second strip 83 is 
secured to second bag wall 90 in a similar fashion. In the FIG. 5 
embodiment, second gripper ridge 76 and fourth gripper ridge 84 are 
oriented on the exterior of first and second strips 73, 83, while first 
and third gripper ridges 74, 82 are oriented on the interior of first and 
second strips 73, 83. This provides the user with a structure to grip on 
the bag exterior, as well as the bag interior. Other embodiments include 
more or fewer gripper ridges. 
One embodiment of a die for making a gripper ridge is illustrated in FIGS. 
6 and 7. In FIG. 6, a die 92 includes a rounded inlet 94, and a 
slot-shaped outlet 96. Molten thermoplastic material is pushed through the 
inlet 94 and extruded through the outlet 96. The polymer melt is 
transitioned from the rounded inlet 94 to the slot-shaped outlet 96 
through a transition area 91 just below inlet 94. Transition area 91 is 
followed by a land region 93. Land region 93 maintains back-pressure and 
distributes flow throughout the outlet 96. Land region 93 is followed by 
relief area 95, which provides polymer melt to the die plate 97, having a 
profile as illustrated in FIG. 7. 
FIG. 7 details a specific implementation of the die plate profile 98. A 
radius 100 which forms point 54 is about 0.009 inch. In other embodiments, 
the radius 100 is about 0.005 to 0.10 inch. A width 102 across what forms 
end surface 52 is about 0.035 inch. A radius 104 at the intersection of 
what forms end surface 52 and what forms second wall 46 is about 0.009 
inch. A height 106 up to a center of radius of what forms gripping end 54 
is about 0.085 inch. A height 108 of the center of radius 104 is about 
0.066 inch. A radius 110 of the intersection between what forms first wall 
40 and what forms the bag wall is about 0.026 inch. Die profile 98 
includes a peak 112 at its base portion. Peak 112 helps to maintain a flat 
surface at its base portion. This peak helps to further reduce the amount 
of material in the gripper ridge. Furthermore, without peak 112, there 
would be a bulge of material on the exterior of the gripper ridge. Peak 
portion 112 includes radii 114, 116 on opposite sides of peak 112. Radii 
114, 116 are on a radius of about 0.066 inch. A distance 118 between 
center of radius 110 and what forms second wall 46 is about 0.062 inch. A 
radius 120 between what forms second wall 46 and what forms a bag wall is 
about 0.026 inch. A distance 122 between a center of radius 120 and what 
forms second wall 46 is about 0.026 inch. A distance 124 between a center 
of radius 116 and the bottom of die profile 98 is about 0.066 inch. A 
distance 126 between a center of radius 104 and the bottom of die profile 
98 is about 0.067 inch. 
A die profile with dimensions as described herein and illustrated in FIG. 7 
results in a gripper ridge with a minimal amount of material, while still 
enhancing the gripper friction and tactile sensation of the user. The 
dimensions of the extruded profile are considerably less than the 
dimensions of the die plate profile. In other embodiments, other 
dimensions of the die profile are used. 
To achieve the minimal amount of material and advantageous gripper ridge 
shape, certain dimension-based ratios are sometimes advantageous. For 
example, the length of what forms first wall 40 is about 1.5 to 2.5 times 
the thickness of the base of the gripper ridge. The length of what forms 
second wall 46 is about 1 to 2 times the thickness of the base. The length 
of what forms end surface 52 is about 1 to 1.5 times the thickness of the 
base. 
One illustrative way of making a gripper ridge involves a die of a specific 
profile. An example of one useful profile includes a base, a first edge, a 
second edge, and a third edge extending between the first and second 
edges. The first edge extends normal to the base and has a first length, 
while the second edge extends normal to the base and has a second length 
less than the first length. One useful die profile is, for example, that 
as illustrated in FIG. 7. A molten thermo-plastic material is pumped 
through the die inlet, and extruded through the die profile. As it is 
extruded through, it has a shape as illustrated, for example, in FIG. 3. 
In one embodiment, the gripper ridge and reclosable zipper profile are 
extruded together with a wall of a bag. After the extrusion steps, the 
extrusions are cooled, and then formed into a bag. One way of 
accomplishing this is by heat sealing together the bag walls, and then 
cutting them apart into individual bags. 
In another embodiment, the gripper ridge and reclosable closure profile are 
extruded together with a strip. Next, the strip is secured to a sheet of 
polymeric material by, for example, heat sealing. The panel sections of 
the bag are then secured together by, for example, heat sealing. 
Other embodiments of the invention will be apparent to those skilled in the 
art from consideration of the specification and practice of the invention 
disclosed herein. It is intended that the specification and examples be 
considered as exemplary only, with a true scope and spirit of the 
invention being indicated by the following claims.