Note: Descriptions are shown in the official language in which they were submitted.
EXTENDED HEM FOLD DRAWSTRING BAG
1110011
BACKGROUND OF THE INVENTION
1. Field of the Invention
100021 The present invention relates to improvements in the construction and
manufacture of
polymeric bags. In particular, the present invention relates to improvements
to trash bags.
2. Description of the Related Art
100031 Polymeric bags are ubiquitous in modem society and are available in
countless
combinations of varying capacities, thicknesses, dimensions and colors. The
bags are available
for numerous applications including typical consumer applications such as long-
term storage,
food storage, and trash collection. Like many other consumer products,
increased demand and
new technology have driven innovations in polymeric bags improving the utility
and
performance of such bags. The present invention is an innovation of particular
relevance to
polymeric bags used for trash collection.
100041 Polymeric bags are manufactured from polymeric film produced using one
of several
manufacturing techniques well-known in the art. The two most common methods
for
manufacture of polymeric films are blown-film extrusion and cast-film
extrusion. In blown-film
extrusion the resulting film is tubular while cast-film extrusion produces a
generally planar film.
Regardless of the manufacturing method utilized, the present invention is
generally applicable to
drawstring trash bags typically manufactured from a continuous web of plastic
film.
Manufacturing methods for the production of drawstring bags from a web of
material are shown
in numerous prior art references including, but not limited to. United States
Patent Nos.
3,196,757 and 4,624,654.
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[0005] Drawstring trash bags are frequently used in connection with rigid
containers. When
used with a rigid container, it is common to fold the upper opening of a
drawstring trash bag over
the upper rim of the container to keep the upper opening of the bag
accessible. Some rigid
containers provide retaining devices to hold the upper opening of a drawstring
bag in place
while, in other instances, the drawstring bag may provide certain features or
properties that
facilitate keeping the bag in place on the container. The use of these rigid
containers is
particularly common in connection with 13-gallon drawstring bags typically
used in the
household or in an office environment. Rigid containers may also be used with
larger bags, such
as those commonly used for the collection of outdoor or yard waste. When
drawstring bags are
used with supporting rigid containers, the drawstring trash bag is often
filled with trash and other
debris until the capacity of the container or trash bag is reached.
[0006] After filling the drawstring bag with trash or debris, the bag and its
contents are
generally pulled out of the rigid container in one of several ways. Some
consumers may prefer
to pull the drawstrings taut, using the drawstrings to pull the bag and its
contents out of the
container. However, in many cases, consumers pull the bag out of the rigid
container before
pulling the drawstrings taut. In such cases, a consumer will typically grab
the upper opening of
the bag hem or, more commonly, the area immediately below the hem. As the
consumer grabs
the bag and pulls it out of the container, significant force can result in the
area immediately
below the hem due to the weight of the bag contents and the pulling action by
the consumer,
which can cause the plastic film to puncture or fail in this region of the bag-
-especially when the
contents of the bag are particularly heavy.
[0007] Another aspect of prior art drawstring bags that may be subject to
improvement is the
tendency for the hems of drawstring bags to detach if there are even minor
manufacturing
defects. In particular, if the pressure or heat used to create the hem seal
across the width of the
drawstring trash bag is too great, the integrity of the drawstring trash bag
may be endangered due
to crystallization of the polymeric film along the hem seal. In these cases,
when the drawstring
trash bag is filled with trash or debris, the hem seal may fail causing the
entire length of the hem,
and the drawstring contained within the hem, to "zipper" or detach from the
rest of the bag. The
present invention may provide additional advantages by providing alternatives
to traditional hem
seals thereby overcoming the tendency of drawstring trash bags to fail in this
manner.
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[0008] In light of the foregoing, it would be desirable to provide a means for
reinforcing the
drawstring trash bag in the area immediately adjacent/below the hem area of
the trash bag. The
present invention represents a novel solution to address this need.
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SUMMARY OF THE INVENTION
[0009] In at least one embodiment of the present invention, a thermoplastic
bag has a front
panel and a back panel. The front panel and back panel are generally joined
along a first side
edge, a second side edge, and a bottom edge of the respective front panel and
back panel. The
front panel also has a distal edge. A first overlap area comprises at least
two layers of polymeric
film below the upper opening of the thermoplastic bag. Furthermore, the at
least two layers of
polymeric film of the first overlap area are generally sealed together.
[0010] In some embodiments of the present invention, the thermoplastic bag may
have a first
hem immediately above the first overlap area. Additionally, a drawstring may
be disposed within
the first hem. In some embodiments, a first hem seal may be formed between the
first hem and
the first overlap area with the first hem seal extending generally from the
first side edge of the
thermoplastic bag to the second side edge of the thermoplastic bag.
[0011] In some embodiments, a first lower seal is located proximate the distal
edge of the front
panel and extends generally from the first side edge of the thermoplastic bag
to the second side
edge of the thermoplastic bag. In some such embodiments, the first lower seal
is generally
continuous while in other embodiments the first lower seal is intermittent.
[0012] In certain embodiments, the first overlap area has a height defined by
a distance from a
lower boundary of the first hem to the distal edge of the front panel with the
height of the first
overlap area being at least 1 inch. Additionally, in certain embodiments, the
height of the first
overlap area is less than 12 inches while in certain preferred embodiments the
height of the first
overlap area is in the range of 1.5 inches to 8 inches.
[0013] In certain embodiments, the at least two layers of polymeric film of
the first overlap
area are generally sealed together by a first plurality of lower seals
extending between a lower
boundary of the first hem to the distal edge of the front panel. Furthermore,
the first hem seal
may be formed between the first hem and the first overlap area with the first
hem seal extending
generally from the first side edge of the thermoplastic bag to the second side
edge of the
thermoplastic bag. The first plurality of lower seals may comprise a plurality
of angular seals,
each of the plurality of angular seals extending generally downwardly from the
lower boundary
of the first hem to proximate the distal edge of the front panel.
Alternatively, the plurality of
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lower seals may extend generally from the first side edge of the thermoplastic
bag to the second
side edge of the thermoplastic bag and from the lower boundary of the first
hem to a point
proximate the distal edge of the front panel. In certain embodiments, the
plurality of lower seals
may comprise angular seals extending across the height of the overlap area
while in other
embodiments the plurality of lower seals may comprise a plurality of
alternating smaller sealed
areas.
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BRIEF DESCRIPTION OF THE RELATED DRAWINGS
[0014] A full and complete understanding of the present invention may be
obtained by
reference to the detailed description of the present invention and certain
embodiments when
viewed with reference to the accompanying drawings. The drawings can be
briefly described as
follows.
[0015] Figure 1 provides a perspective view of a first embodiment of the
present invention.
[0016] Figure 2 provides an elevation view of the front panel according to a
first embodiment
of the present invention.
[0017] Figure 3 provides an elevation view of the back panel according to a
first embodiment
of the present invention.
[0018] Figure 4 provides a cross section perspective view of a first
embodiment of the present
invention.
[0019] Figure 5 provides a perspective view of a second embodiment of the
present invention.
[0020] Figure 6 provides an elevation view of a panel according to a second
embodiment of
the present invention.
[0021] Figure 7 provides a perspective view of a third embodiment of the
present invention.
[0022] Figure 8 provides an elevation view of a panel according to a third
embodiment of the
present invention.
[0023] Figure 9 provides a perspective view of a fourth embodiment of the
present invention.
[0024] Figure 10 provides an elevation view of a panel according to a fourth
embodiment of
the present invention.
[0025] Figure 11 provides a perspective view of a fifth embodiment of the
present invention.
[0026] Figure 12 provides an elevation view of a panel according to a fifth
embodiment of the
present invention.
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[0027] Figure 13 provides a perspective view of a sixth embodiment of the
present invention.
[0028] Figure 14 provides an elevation view of a panel according to a sixth
embodiment of the
present invention.
[0029] Figure 15A provides an elevation view of a seventh embodiment of the
present
invention.
[0030] Figure 15B provides an enlarged elevation view of a portion of a
seventh embodiment
of the present invention.
[0031] Figure 16 provides a perspective view of a panel according to a seventh
embodiment of
the present invention.
[0032] Figure 17 provides an elevation view of an eighth embodiment of the
present
invention.
[0033] Figure 18 provides a perspective view of a panel according to an eighth
embodiment of
the present invention.
[0034] Figure 19 provides an elevation view of a ninth embodiment of the
present invention.
[0035] Figure 20 provides a perspective view of a panel according to a ninth
embodiment of
the present invention.
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[0036] DETAILED DESCRIPTION OF THE INVENTION
[0037] The present disclosure illustrates several embodiments of the present
invention. It is
not intended to provide an illustration or encompass all embodiments
contemplated by the
present invention. In view of the disclosure of the present invention
contained herein, a person
having ordinary skill in the art will recognize that innumerable modifications
and insubstantial
changes may be incorporated or otherwise included within the present invention
without
diverging from the spirit of the invention. Therefore, it is understood that
the present invention
is not limited to those embodiments disclosed herein. The appended claims are
intended to more
fully and accurately encompass the invention to the fullest extent possible,
but it is fully
appreciated that certain limitations on the use of particular terms are not
intended to conclusively
limit the scope of protection.
[0038] Figure 1 provides a perspective view of a first embodiment of the
present invention
while Figure 2 and Figure 3 show a front and rear elevation of the same
embodiment. Looking
collectively at Figures 1-3, a drawstring trash bag 100 according to one
embodiment is
comprised of a front panel 102 and a back panel 104, the front panel 102 and
back panel 104
being substantially rectangular in shape and joined along a first side edge
110, a second side edge
112, and a bottom edge 114 to provide the body of the bag. The front panel 102
and back panel
104 may be formed from a single piece of polymeric film which is folded to
define the bottom
edge 114 and subsequently sealed along the first side edge 110 and second side
edge 112.
However, other manufacturing configurations may be utilized in conjunction
with the present
invention. hi certain embodiments, the front panel 102 and the back panel 104
are formed by
plastic films that are substantially uniform in thickness, subject to standard
manufacturing
tolerances and variations, with an average thickness of between 0.4 mils and 4
mils for each
panel 102, 104. Moreover, in some embodiments, the average thickness of each
of the respective
panels 102, 104 is between 0.6 mil and 1.0 mil. Moreover, in certain preferred
embodiments, the
average thickness of each of the respective panels 102, 104 is between 0.75
mils and 1.0 mils.
[0039] In certain embodiments of the present invention, including the
embodiment depicted in
Figure 1, the front panel 102 and back panel 104 of the drawstring trash bag
100 are comprised
of a polymer blend, the polymer blend generally having linear low density
polyethylene
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(LLDPE) as the primary component, but other polymers may be utilized
including, but not
limited to, other polyethylenes such as high density polyethylene (HDPE) or
low density
polyethylene (LDPE). Typically, the primary component of the polymer blend,
such as linear
low density polyethylene (LLDPE), will comprise at least 75% of the polymer
blend. The
remaining portion of the polymer blend may include additives including, but
not limited to,
coloring additives, anti-blocking agents, and/or odor control additives.
[0040] Looking briefly at Figure 4, a cross-section view of one embodiment of
the present
invention, better illustrates certain aspects, features, and advantages of the
present invention. In
particular, an upper cross-section of a drawstring trash bag 100 is depicted
although the
thicknesses and dimensions are exaggerated to better illustrate the relation
between the various
parts of the particular embodiment. During manufacture of the drawstring trash
bag, the distal
edge 116 of the front panel 102, i.e. the edge of the folded-over portion of
the front panel 102
results from the fold-over defining the first hem 122 in the front panel 102
and a first drawstring
132 is disposed within the first hem 122. Similarly, the distal edge 118 of
the back panel 104
results from the fold-over defining the second hem 124 with a second
drawstring 134 disposed in
the second hem 124. The upper boundaries of the hems 122, 124 define the upper
opening 120
of the drawstring trash bag 100.
[0041] The drawstrings 132, 134 may be comprised of traditional high-density
polyethylene
drawstrings or, in some embodiments, elastic or elastic-like polymeric
components. The
drawstrings 132, 134 are anchored to the front panel 102 and back panel 104 at
the ends of the
respective drawstrings 132, 134 near the first side edge 110 and second side
edge 112. In
particular, the drawstrings 132, 134 are commonly anchored using short seals
136, 138 as shown
in Figures 1-3, the short seals 136, 138 fusing both drawstrings 132, 134 with
both the front
panel 102 and the back panel 104. Other than the anchor point, the drawstrings
132, 134 are
generally loose within the hems 122, 124 enabling the drawstrings 122, 124 to
be accessed and
pulled through the respective drawstring cutouts 126, 128 centrally located
between the first side
edge 110 and second side edge 112. Consequently, when the drawstrings 132, 134
are pulled
through the drawstring cutouts 126, 128 of the drawstring trash bag 100, the
respective upper
corners of the drawstring trash bag 100 are pulled together to facilitate
closure of the bag.
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[0042] Now
looking at Figures 1-4, according to the depicted embodiment of the present
invention, the distal edges 116, 118 of the respective front and back panels
102, 104 are located a
distance below the respective hems 122, 124. Thus, the front panel 102 has an
overlap area 142
that extends from the lower boundary of the first hem 122 to the distal edge
116 of the front
panel 102. In the same manner, the back panel 104 has an overlap area 144 that
extends from the
lower boundary of the second hem 124 to the distal edge 118 of the back panel
104. Thus, for
the front panel 102, the overlap area 142 comprises two layers of polymeric
film, and the hem
overlap area 144 of the back panel 104 also comprises two layers of polymeric
film according to
the depicted embodiment. The length of the first overlap area 142 and the
second overlap area
144 can be selected to be any length including a distance ending only slightly
below the bottom
boundaries of the respective hems 122, 124 or a distance that extends nearly
to the bottom of the
bag. However, in certain embodiments, it is desirable to provide a first
overlap area 142 or
second overlap area 144 of between 1 inch and 12 inches with a preferred range
of 1.5 inches to
8 inches.
[0043] The overlap areas 142, 144 as shown in the depicted embodiments provide
important
benefits during use of the drawstring trash bag 100. The primary benefit
offered by the overlap
areas 142, 144 is reinforcing the drawstring trash bag 100 in the areas
immediately below the
hems 122, 124. As best illustrated by Figure 4, it can be seen that the
thickness of the polymeric
film is essentially doubled in the overlap areas 142, 144 compared to the
remaining area of the
front panel 102 and back panel 104 below the overlap areas 142, 144. The
thicker overlap area
142, 144 is therefore expected to be stronger than the remainder of the bag.
Thus, in the event
that a consumer is carrying the bag or gripping the bag in one or both of the
overlap areas 142,
144, it is less likely that the drawstring trash bag 100 will puncture or tear
in that particular area.
By reducing the likelihood that the drawstring trash bag 100 will fail when a
consumer grabs the
drawstring trash bag 100 in the overlap areas 142, 144, the drawstring trash
bag 100 is more
useful--especially when it contains heavier items or debris.
[0044] The depicted embodiment of Figures 1-4 is illustrated as having hem
seals 162, 164
extending the width of the drawstring trash bag 100. Additionally, lower seals
172, 174 are
provided in the respective panels 102, 104 proximate to the respective distal
edges 116, 118. By
providing hem seals 162, 164 near the top of the overlap areas 142, 144 and
lower seals 172, 174
CA 02804614 2013-01-31
near the bottom of the overlap areas 142, 144, the two layers of plastic film
comprising each
overlap area 142, 144 are kept in close proximity, providing effectively a two-
ply polymeric film
of double thickness in the region of the overlap areas 142, 144. For example,
in the case of a
front panel 102 and back panel 104 each having a nominal thickness of 0.7 mil,
the overlap areas
142, 144 provide a thickness of roughly 1.4 mils, thereby providing a much
stronger area for a
consumer to grab, pull, and lift the trash bag.
[0045] Figure 5 and Figure 6 depict a second embodiment of the present
invention.
Specifically, Figure 5 shows a perspective view of a drawstring trash bag 500
according to the
disclosed embodiment with Figure 6 illustrating an elevation view of the front
panel 102.
Although not expressly shown, a person of ordinary skill in the art would
understand that the
back panel 104 of the depicted embodiment could be constructed in the same
manner as the
depicted front panel 102 or in any other manner consistent with the present
disclosure.
[0046] Looking at Figure 5 and Figure 6 together, the depicted embodiment of a
drawstring
trash bag 500 is very similar to the embodiment depicted earlier in Figures 1-
3 with the
exception that instead of continuous lower seals extending across the width of
the bag shown in
the prior embodiment, in the depicted embodiment the lower seals 572, 574 are
intermittent
across the width of the drawstring trash bag 500. The intermittent
configuration of the seals
facilitates the release of air that could potentially be trapped within the
overlap areas 142, 144
during both manufacture and use of the drawstring trash bag 500.
[0047] Figure 7 and Figure 8 depict a third embodiment of the present
invention.
Specifically, Figure 7 shows a perspective view of a drawstring trash bag 700
according to the
disclosed embodiment with Figure 8 illustrating an elevation view of the front
panel 102.
Although not expressly shown, a person of ordinary skill in the art would
understand that the
back panel 104 of the depicted embodiment is constructed to be a mirror image
of the front panel
102, but could also be constructed in any other manner consistent with the
present disclosure.
[00481 Looking at Figure 7 and Figure 8 together, the drawstring trash bag 700
lacks the
transverse lower seals 172, 174 of previous embodiments and instead has lower
seals 772, 774
comprised of a series of angular seals extending substantially across the
entire height of the
overlap areas 142, 144, extending generally from the area below the hem seals
162, 164 down to
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a point just above the distal edges 116, 118 of the respective front panel 102
and back panel 104.
As with the hem seals 162, 164 and the lower seals 172, 174 of prior
embodiments, the angular
lower seals 772 join the overlap area 142 of the front panel 102 to the body
portion of the same
front panel 102. Similarly, angular lower seals 774 bond the overlap area 144
of the back panel
104 to the body portion of the same back panel 104. This configuration of the
angular seals
comprising the lower seals 772, 774 also facilitates the escape of any air
trapped within the
overlap areas 142, 144 during manufacture or use of the drawstring trash bag
700.
[0049] A fourth embodiment of the present invention is shown in Figure 9 and
Figure 10,
which discloses a drawstring trash bag 900 which again lacks the lower seals
172, 174 of
previous embodiments and instead has lower seals 972, 974 comprised of a
plurality of
alternating smaller sealed areas, the individual sealed areas of lower seals
972 of the front panel
102 bonding the overlap area 142 of the front panel 102 to the body portion of
the same front
panel 102. Similarly the individual sealed areas of the lower seals 974 bond
the overlap area 144
of the back panel 104 to the body portion of the same back panel 104.
[0050] A fifth embodiment of the present invention is shown in Figure 11 and
Figure 12,
which is similar to the previously disclosed third embodiment. In this fifth
disclosed
embodiment, the drawstring trash bag 1100 has lower seals 1172, 1174 comprised
of a series of
sealed angular seals extending substantially across the height of the overlap
areas 142, 144 down
to a point just above the distal edges 116, 118 of the respective front panel
102 and back panel
104. However, unlike previous embodiments, in this embodiment, traditional hem
seals 162, 164
are omitted with the lower seals 1172, 1174 defining the bottom boundaries of
the hems 122,
124.
[0051] A sixth embodiment of the present invention is shown in Figure 13 and
Figure 14,
which is similar in some aspects to the previously disclosed fourth
embodiment. In this sixth
disclosed embodiment, the drawstring trash bag 1300 has lower seals 1372, 1374
comprised of a
plurality of alternating smaller sealed areas, the individual sealed areas of
lower seals 1372 of the
front panel 102 bonding the overlap area 142 of the front panel 102 to the
body portion of the
same front panel 102. Similarly the individual sealed areas of the lower seals
1374 bond the
overlap area 144 of the back panel 104 to the body portion of the same back
panel 104. Lower
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seals 1372, 1374 extend generally across the entire height of the overlap
areas 142, 144 to a point
just above the distal edges 116, 118 of the respective front panel 102 and
back panel 104.
However, in the same manner as disclosed with respect to the fifth embodiment,
traditional hem
seals 162, 164 are omitted with certain lower seals 1372, 1374 defining the
bottom boundaries of
the hems 122, 124.
[0052] A seventh embodiment of the present invention is shown in Figure 15A,
Figure 15B
and Figure 16. In this seventh disclosed embodiment, the drawstring trash bag
1500 has a
plurality of triangular embossed areas 1576, each triangular embossed area
1576 comprising a
plurality of embosses, preferably circular embosses. The triangular embossed
areas 1576 extend
substantially across the height of the overlap areas 142, 144 down to a point
just above the distal
edges 116, 118 of the respective front panel 102 and back panel 104. In this
particular
embodiment, the triangular embossed areas 1576 are separated from one another
by sets of
sealed bands 1580, 1582, 1584. Each set of sealed bands 1580, 1582, 1584
comprises a set of
substantially parallel sealed areas extending across the overlap areas 142,
144. The first set of
sealed bands 1580 may extend in a direction generally parallel with the upper
opening 120 and
bottom of the bag. The second and third set of sealed bands 1582, 1584 are
offset from one
another, and the first set 1580, by approximately 60 degrees. Each of the set
of sealed bands
1580, 1582, 1584 seals the overlap areas 142, 144 to the respective panels
102, 104.
[0053] An eighth embodiment of the present invention is shown in Figure 17 and
Figure 18.
In this eighth disclosed embodiment, the drawstring trash bag 1700 has a
plurality of
parallelogram embossed areas 1776, each parallelogram embossed area 1776
comprising a
plurality of embosses, preferably circular embosses. The parallelogram
embossed areas 1776
extend substantially across the height of the overlap areas 142, 144 down to a
point just above
the distal edges 116, 118 of the respective front panel 102 and back panel
104. In this particular
embodiment, the parallelogram embossed areas 1776 are separated by sealed
bands 1780. The
sealed bands 1780 are substantially parallel to each other and extend across
the overlap areas
142, 144, preferably at an angle other than parallel to one of the sides 110,
112, including the
upper opening 120 or bottom 114, of the drawstring trash bag 1700.
[0054] A ninth embodiment of the present invention is shown in Figure 19 and
Figure 20. In
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this ninth disclosed embodiment, the drawstring trash bag 1900 has lower seals
1972, 1974
comprised of a series of curvilinear seals extending substantially across the
height of the overlap
areas 142, 144 down to a point just above the distal edges 116, 118 of the
respective front panel
102 and back panel 104. In this particular embodiment, the curvilinear seals
1972, 1974 are
generally U-shaped with a narrowing along the middle of the U-shape. More
importantly, the
curvilinear lower seals 1972, 1974 are advantageous because the curvilinear
edges of the
respective seals 1972, 1974 reduce the likelihood of tears propagating. Like
other previous
embodiments, traditional hem seals are omitted with the lower seals 1972, 1974
defining the
bottom boundaries of the hems 122, 124.
100551 As previously noted, the specific embodiments depicted herein are not
intended to limit
the scope of the present invention. Indeed, it is contemplated that any number
of different
embodiments may be utilized without diverging from the spirit of the
invention. Therefore, the
appended claims are intended to more fully encompass the full scope of the
present invention.
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