U.S. patent application number 12/643115 was filed with the patent office on 2011-06-23 for bag and article of manufacture.
Invention is credited to James Scott Bradley, David P. Cameron, Justin Alan Ellsworth, George Scott Kerr, David Brian Long, Allan Jay Root, Lawrence Andrew Schumacher, Solomon O'Neil West.
Application Number | 20110150368 12/643115 |
Document ID | / |
Family ID | 43598002 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110150368 |
Kind Code |
A1 |
Ellsworth; Justin Alan ; et
al. |
June 23, 2011 |
Bag and Article of Manufacture
Abstract
An article of manufacture including a bag made of a multi-layer
laminate. The bag can have a front surface, a rear surface, two
side surfaces, a bottom surface, and a top surface; the bag having
a height, a width, and a depth, and an internal volume. The bag can
be sealable and have a seal strength of at least about 1,600 pounds
per square inch. The multi-layer laminate can have a thickness of
from about 130 to about 200 microns. The plastic laminate can
include an inner layer and an outer layer, wherein the outer layer
can include a nylon and the inner layer can include a polyethylene.
The plastic laminate can have a dart drop resistant of at least
about 5 grams/mil and a tear resistance of at least about 6
grams/mil and 9 grams/mil in the machine direction and cross
direction, respectively.
Inventors: |
Ellsworth; Justin Alan;
(Sharonville, OH) ; Schumacher; Lawrence Andrew;
(Trenton, OH) ; Kerr; George Scott; (Mason,
OH) ; Root; Allan Jay; (Springboro, OH) ;
Cameron; David P.; (Canandiagua, NY) ; Long; David
Brian; (Pauline, SC) ; West; Solomon O'Neil;
(Whitby, CA) ; Bradley; James Scott; (Battle
Creek, MI) |
Family ID: |
43598002 |
Appl. No.: |
12/643115 |
Filed: |
December 21, 2009 |
Current U.S.
Class: |
383/6 ; 383/109;
383/120; 383/200 |
Current CPC
Class: |
B65D 31/10 20130101;
B65D 31/16 20130101; B65D 33/1691 20130101; B65D 33/25 20130101;
B65D 31/02 20130101 |
Class at
Publication: |
383/6 ; 383/200;
383/120; 383/109 |
International
Class: |
B65D 33/06 20060101
B65D033/06; B65D 33/00 20060101 B65D033/00; B65D 30/20 20060101
B65D030/20; B65D 30/08 20060101 B65D030/08 |
Claims
1. An article of manufacture comprising: a) a bag comprising a
front surface, a rear surface, two side surfaces, a bottom surface,
and a top surface; the bag having a height, a width, and a depth,
and an internal volume; wherein the bag is sealable and has a seal
strength of at least about 1,600 pounds per square inch; and
wherein the bag comprises a multi-layer laminate having a thickness
of from about 130 to about 200 microns; wherein the plastic
laminate comprises a polyamide; wherein the plastic laminate has a
dart drop resistant of at least about 5 grams/mil and a tear
resistance of at least about 6 grams/mil and 9 grams/mil in the
machine direction and cross direction, respectively; b) the bag
having a height between about 18 inches and 40 inches, a width
between 11 inches and 18 inches, and a depth between 2.5 inches and
9 inches; c) at least about 10 liters of a particulate, flowable
composition contained in the bag.
2. The article of manufacture of claim 1 and wherein the bag has a
tear strength of at least about 15 pounds per square inch as
measured in the transverse direction.
3. The article of manufacture of claim 1 and wherein the
multi-laminate comprises an outer layer and an inner layer.
4. The article of manufacture of claim 2 and wherein the outer
layer comprises a nylon and the inner layer comprises a
polyethylene.
5. The article of manufacture of claim 4 and wherein the nylon
comprises Nylon 6,6.
6. The article of manufacture of claim 1 wherein the bag contains
at least about 20 liters of said particulate, flowable
composition.
7. The article of manufacture of claim 1 wherein the bag has a
ratio of said width to said height of from about 0.4 to about
0.8.
8. The article of manufacture of claim 7 wherein the ratio of the
width to the height is about 0.6.
9. The article of manufacture of claim 1 wherein the bag has a
ratio of the depth to the height of from about 0.17 to about
0.4.
10. The article of manufacture of claim 9 wherein the bag has a
ratio of the depth to the height of from about 0.17 to about
0.3.
11. The article of manufacture of claim 1 wherein the bag has a
ratio of the width to a height of from about 0.4 to about 0.8 and a
ratio of the depth to the height of from about 0.17 to about
0.4.
12. The article of manufacture of claim 1 wherein said internal
volume, said depth of said bag, and said gussets, in combination
form a grippable portion near said top of said bag, by which said
bag can be grasped for lifting.
13. The article of manufacture of claim 1 further comprising a
non-reusable closure; wherein said non-reusable closure has a
length that extends along said width of said bag, and wherein said
non-reusable closure comprises a membrane between said front
surface and said rear surface of said bag, said membrane having a
user-facing surface, an outer surface, and a tear strength of at
least about 15 pounds per square inch.
14. The article of manufacture of claim 13 wherein said membrane
comprises a targeted opening region that has a tear strength of
from about 1 to about 15 pounds per square inch.
15. The article of manufacture of claim 12 wherein said targeted
opening region comprises a plurality of perforations in said
membrane.
16. The article of manufacture of claim 1 wherein said plastic
laminate has an oxygen transmission rate of less than about 6.5
cc/100 in2/24 hours.
17. The article of manufacture of claim 1 wherein said plastic
laminate has a moisture vapor transmission rate of less than about
0.1 grams/100 in2/24 hours.
18. The article of manufacture of claim 1 wherein said bag has a
tip angle of from about 10.degree. to about 50.degree..
19. The article of manufacture of claim 1 wherein said composition
comprises a dry pet food.
20. The article of commerce of claim 1 and wherein the bag has a
height of from about 18 inches to about 40 inches a width from
about 11 inches to about 18 inches and a depth from about 2.5
inches to about 9 inches.
Description
FIELD
[0001] The invention relates generally to bags for containing
particulate, flowable compositions. More particularly, embodiments
of the present invention relate to bags that can be made of
laminates.
BACKGROUND
[0002] Industries that use and sell large quantities of bulk,
particulate, flowable compositions, such as animal food, bulk
foods, coffee, fertilizer, detergent, and the like are often faced
with the task of packaging and shipping such compositions in
containers suitable for shipping, handling, retail sale, and
consumer transport and use. For compositions such as bulk animal
foods, such containers are typically paper or plastic bags
containing up to about 75 pounds of food composition. Such
containers therefore must be able to withstand shipping and
handling without breaking open.
[0003] Bags for containing and handling bulk compositions are made
from various materials and secured closed in various ways depending
on the properties of the bag materials, the properties of the
closure systems, and cost considerations. Materials used for such
bags include burlap, paper, multi-layer, and plastics. Closure for
one-time use can be accomplished by stitching, taping, gluing, heat
sealing, and/or ultra sonic welding the containers closed after the
containers are filled with the composition. The cost to produce
such bags and closures varies with the type of bag material and
type of closure used. In the retail pet food industry, such bags
have typically been made from multiple layers of paper, plastic,
and/or foil, and stitched, taped, glued, heat sealed, and/or
ultrasonically welded closed.
[0004] The materials and closures of such bags are typically
selected to provide the most cost-effective container, considering
material cost, material properties, closure cost, closure
properties, damage and lost product due to bag breakage, etc. Bags
for containing quantities of 15 or more pounds of dry pet food
composition are typically multiple layered paper bags, often lined
with plastic or foil on an interior surface thereof, that are
stitched, taped and/or glued closed.
[0005] However, paper bags do not keep the food compositions
contained therein particularly fresh over time. Oxygen, moisture,
and even perhaps organisms can enter the bags. Thus, in time, the
food may oxidize, become stale, become infested, and generally
become less palatable to the animal and less desirable by the
animal owner. Additionally, bags that are stitched, taped and/or
glued closed can not be resealed once opened. Therefore, many
animal owners resort to emptying the contents of the paper bag into
a storage container that can be easily accessed, easily reclosed,
and that keeps the food fresh.
[0006] Furthermore, such feed bags are typically rectangularly
shaped with very small depth versus height of such bags. Thus, the
bags must be stacked and displayed laying flat on one of the
largest surfaces, typically the front or back surface. Such
orientation, particularly for bags containing 15 or more pounds of
composition, makes the bags difficult to display and to remove and
lift. If such bags are successfully removed from a store shelf,
they are often deposited on a narrow bottom surface of the bag, and
often fall over. The instability of the bags can be bothersome if
one must keep righting the bag. In addition, if the bag has been
taken home and opened, extensive spillage can result when the bag
tips over.
[0007] Recently, manufacturers have attempted to provide bags that
are reclosable and that provide enhanced spoilage protection for
the contents over time, such that a user does not have to empty a
large, heavy bag into a separate container. Therefore,
manufacturers have begun to supply plastic bags, or paper bags with
plastic or foil linings, and having reclosable features. Plastic,
and plastic or foil lined materials are better moisture and
air/oxygen barriers than, for example, paper or burlap, and provide
better protection from spoilage and infestation.
[0008] However, it has been found that many such plastic bags burst
open, when filled with about 15 or more pounds of bulk composition,
and dropped off of a truck, a store shelf, out of a user's vehicle
or grip, or when tipped over. The bursting problem is often
exacerbated when such bags are formed with a reclosable feature.
Such bags can burst at the site of the reclosable feature or at one
or more seals or seams of the bag, or the material forming the bag
itself can tear and cause the bag to burst open. In addition,
plastic bags can be slippery to the touch, and can result in a
greater amount of bags dropped versus other materials such as paper
or burlap.
[0009] Some manufactures have attempted to solve the problem of
bags bursting at a reclosable feature by placing and sealing a
material over or across the reclosable feature, which the consumer
then removes once the bag is safely at its final destination. Such
an approach is feasible with various paper bags, and quantities of
composition over about 15 pounds in weight. However, many plastic
bags still burst when they contain over about 15 pounds of material
and fall from a height of about 3 feet, whether or not the bags
contain a reclosable feature. Thus, the majority of bags used for
containing greater than about 15 pounds of dry pet food are various
types of paper bags. Other approaches include sealing the inside of
the bag in addition to having a reclosable feature. Using a double
thickness in the reclosable feature is another option. However,
cost can increase prohibitively as more components are added to the
bag.
[0010] Therefore, there is a need for a plastic bag that can
contain amounts of compositions and can withstand a drop from
heights without bursting open. There is also a need for such a bag
to be reclosable. There is a need for such a bag to also provide
moisture and oxidation barrier protection for the contents. There
is also a need for the bag to be stable when situated upright on a
bottom surface of the bag, and for the bag to be easily
grippable.
SUMMARY
[0011] Embodiments of the present invention relate to articles of
manufacture comprising a bag. The bag can be used for containing
large quantities of particulate, flowable compositions such as dry
pet food. The bags can comprise a multi-layer laminate having a
thickness of from about 130 to about 200 microns; wherein the
plastic laminate comprises a polyamide. The plastic laminate can
have a dart drop resistant of at least about 5 grams/mil and a tear
resistance of at least about 6 grams/mil and 9 grams/mil in the
machine direction and cross direction, respectively. The bag having
a height between about 18 inches and 40 inches, a width between 11
inches and 18 inches, and a depth between 2.5 inches and 9 inches
and can contain at least about 10 liters of a particulate, flowable
composition contained in the bag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of a bag of one embodiment of
the present invention.
[0013] FIG. 2 is a perspective view of an alternative embodiment of
the present invention.
[0014] FIG. 3 is a perspective cutaway view showing a bag of one
embodiment of the present invention filled with particulate,
flowable composition.
[0015] FIG. 4 is a top perspective view of a bag illustrating a
non-reusable closure of one embodiment of the present
invention.
[0016] FIG. 5 is a cross-sectional side view of the membrane of one
embodiment of the invention.
[0017] FIG. 6 is a perspective view of a bag having a non-reusable
closure partially installed therein.
[0018] FIGS. 7a-c are perspective views of the non-reusable closure
of one embodiment of the present invention illustrating the
targeted openable region.
DETAILED DESCRIPTION
[0019] All measurements made herein art made at 25.degree. C.
unless otherwise designated.
[0020] The term "particulate, flowable compositions", as used
herein and usable with the present invention, means compositions
including animal feeds including rodent, dog, cat, horse, goat,
cattle, pig, bird, and the like; detergents; fertilizers; cat
litter; bulk foods including grains, nuts, beans, fruits, and the
like.
[0021] The term "slack fill", as used herein, means to fill a
container with a composition during manufacturing and/or packaging
such that the composition occupies a volume less than the interior
volume of the container, thereby leaving a "head space", meaning
empty portion of volume, in the container.
[0022] The term "seal", as used herein, means the seal or seals
that form the bag itself, and which can be formed by sealing the
surfaces, such as the inner surfaces, of the plastic laminate
together; and in addition means the seals formed when sealing a
non-reusable closure to the top of the bag, if such a non-reusable
closure is used.
[0023] The term "seal strength", as used herein, refers to a
measure of tensile strength at each seal made and used in forming
the bag.
Article of Manufacture
Bag
[0024] One embodiment of the present invention encompasses articles
of manufacture illustrated in FIGS. 1-7. As shown in FIGS. 1 and 2,
the article of manufacture comprises a bag 10 comprising a front
surface 12 and a rear surface 14 extending upwardly from a bottom
surface 16, which can be flattenable, especially when formable
material is used to construct the article. Two side surfaces 18
each can be an expandable gusset 20, which can include a region of
the side surface that folds to form a crease, therein connecting
front surface 12 and rear surface 14 at opposite sides of bag 10.
The bag 10 also can have a flattenable bottom surface 16 that can
be formed by connecting front surface 12, rear surface 14, and side
surfaces 18. Bag 10 also can have a top surface 22 formable by
connecting front surface 12, rear surface 14, side surfaces 18, and
located opposite flattenable bottom surface 16. The bag has a
height H, a width W, a depth D. The height H, width W, and depth D
of bag 10 are defined and measured as internal dimensions of bag
10, measured from the inside surfaces of the bag. The height H is
measured along the front or rear face of the bag from the inside
edge of the bottom seal to the top edge of the bag, not including
any closure. The width is measured across the front or rear face of
the bag from inside of edge seal to inside of edge seal at a
midpoint of the height of the bag. The depth is measured across
either side surface from edge seal to edge seal at a midpoint of
the height of the bag. The height H, width W, and depth D define an
internal volume V.
[0025] The bag 10 can be sealable by methods commonly known in the
art, such as, for example, heat sealing, along at least one edge of
a side surface 18a, 18b, bottom surface 16, and top surface 22. The
bag can also be sealed at each edge 18a, 18b. Such a bag, sealed at
each of the four side edges, can be commonly referred to as a "quad
seal" bag. A quad seal bag is one embodiment described herein. The
seals of the bag can have a seal strength of at least about 1,600
pounds per square inch. The bag can comprise a plastic laminate
having a thickness of from about 130 to about 200 microns. The
plastic laminate can have an impact dart-drop resistance of at
least about 6.2 grams/mil, and a tear resistance of at least about
7.9 grams/mil and 10.8 grams/mil in the machine direction and cross
direction respectively.
[0026] The article of manufacture can comprise, in addition to the
bag, at least about 15 pounds of a particulate, flowable
composition contained therein. Alternatively, the article of
manufacture can comprise at least about 20 pounds of the
particulate, flowable composition, alternatively at least about 30
pounds of the particulate, flowable composition, and alternatively
at least about 40 pounds of the particulate, flowable composition.
The article of manufacture can comprise up to about 75 pounds of
particulate, flowable composition. From a volume perspective, the
article, alternatively or additionally with respect to the weight
above, can contain at least about 10 liters of a particulate,
flowable compositions, or at least about 15 liters, or at least
about 20 liters, or at least about 30 liters, or at least about 40
liters, or at least about 75 liters.
[0027] The bag 10 of the article of manufacture of the present
invention can be formed to have any particular dimensions and any
particular shape. An embodiment of bag 10 of the present invention,
as shown in FIGS. 1 and 2, can have a ratio of width W to height H
of from about 0.4 to about 0.8. Alternatively, the ratio of width W
to height H can be about 0.6. Such a ratio of width W to height H
can help to ensure that bag 10 is stable and resistant to tipping
such that bag 10 can be easily placed and stored on its bottom
surface 16. Such a ratio can result in more of the composition
contained inside the container to be situated such that the
potential for tipping can be decreased. Furthermore, such a width W
to height H ratio can help distribute forces generated on the
plastic laminate and seals if the bag is dropped, such that the
width W to height H ratio aids in making the bag resistant to
breaking or bursting if dropped. Such a ratio can allow forces to
distribute by providing more surface area for the forces to contact
and dissipate through.
[0028] Bag 10 also can have a ratio of depth D to height H of from
about 0.17 to about 0.4. Alternatively bag 10 can have a depth D to
height H ratio of from about 0.17 to about 0.3. The depth D can be
represented by side surface 18. The depth D to height H ratio can
also aid in ensuring that bag 10 can be easily placed and stored on
its bottom surface 16 and be resistant to tipping. In addition, the
depth D to height H ratio can also help distribute forces generated
on the plastic laminate and seals if bag 10 is dropped, such that
the depth D to height H ratio aids in making bag 10 resistant to
breaking or bursting if dropped. Such a ratio allows forces to
distribute by providing more surface area for the forces to contact
and dissipate through.
[0029] Such ratios are not commonly found in commercially available
bags. Most commercially available side gusseted bags have rather
small side gussets, and thus, very small depth to height ratios.
Such small depth to height ratios result in bags that have small
bottom surfaces, and which effectively can not be stood on the
bottom surface without tipping over. Therefore, conventional pet
feed bags must be displayed laid down on either the front or rear
surface and cannot effectively be used throughout the period of use
of the composition contained therein because they do not stand up
well. In addition plastic laminate bags with small side gussets are
much less burst-resistant due to the small surface area of the
sides having the gussets. When such bags are dropped, particularly
on the small, gusseted sides, they are likely to burst due to the
forces created due to the small surface area of the gusseted
sides.
[0030] Therefore, an example combination of ratio of width W to
height H, and ratio of depth D to height H, of a bag of one
embodiment of the present invention, is about 0.6 and about 0.20. A
bag 10 of one embodiment of the present invention, when formed as
described, can withstand a drop from at least about 4 feet, on one
of gusseted sides 18, when filled with at least about 15 pounds of
particulate, flowable composition, and can be very stable and
resistant to tipping. Thus, such a bag can be displayed and sold in
an upright, vertical position and can be easily used as the storage
container for the composition contained therein, throughout the use
of the composition.
[0031] Bags of embodiments of the present invention can have
varying absolute dimensions for height, width, and depth. The
height can range from about 18 inches to about 40 inches, or from
about 20 inches to about 40 inches, or from about 20 inches to
about 39 inches, and all numeric ranges therebetween. The width can
range from about 11 inches to about 18 inches, or from about 13
inches to about 18 inches, or from about 13 inches to about 17.75
inches, and all numeric ranges therebetween. The depth can range
from about 2.5 inches to about 9 inches, or from about 3 inches to
about 9 inches, or from about 3 inches to about 8.5 inches, and all
numeric ranges therebetween. Any combination of these dimensions
can be used.
[0032] As shown in FIG. 3, bag 10 of one embodiment of the present
invention also defines an internal volume V, which can be at least
about 20% greater than a volume Vc occupied by the composition
contained within bag 10, thus creating a head space volume Vh. The
bags can be slack filled such that the composition does not occupy
the entire internal volume V of the bag. The head space volume Vh
allows bag 10 to be easily and securely sealed after filling, helps
to distribute forces generated if bag 10 is dropped to help ensure
bag 10 is burst resistant, and, in combination with the depth D and
gussets 20, provides a grippable portion 24, as seen in FIGS. 1 and
2 near the top surface 22 by which bag 10 can be grasped for
lifting.
[0033] An embodiment of bag 10 can comprise a non-reusable closure
26, shown in FIG. 4, that can aid in ensuring bag 10 is burst
resistant and can provide a tamper evident indicator. Non-reusable
closure 26 can have a length that extends along said width W of bag
10. Non-reusable closure 26 can comprise a membrane 28 disposed,
such as by connected or otherwise attached, between front surface
12 and rear surface 14 of bag 10. The membrane 28 can have a
thickness of from about 170 to about 200 microns. In one
embodiment, non-reusable closure 26 can be utilized on bag 10 in
the machine direction of the material of membrane 28.
[0034] Membrane 28 can have a user-facing surface 30, an outer
surface 32 (as shown in FIG. 5), and a tear strength of at least
about 15 pounds per square inch (PSI), as measured in the
transverse or cross machine direction, by ASTM Method D-882
Standard Test Method for Tensile Properties of Thin Plastic
Sheeting. Non-reusable closure 26 can be disposed at a top edge 34
of bag 10 or, alternatively, can be disposed inward a distance from
top edge 34 of bag 10. In FIG. 4, non-reusable closure 26 is shown
located at top edge 34 of bag 10.
[0035] As shown in FIG. 5, membrane 28 can have a plurality of ribs
36 on outer surface 32 of membrane 28, which enable outer surface
32 to be sealed to front surface 12 of bag 10, and a plurality of
ribs 36 on outer surface 32 of membrane 28 which enable outer
surface 32 to be sealable to rear surface 14 of bag 10 to seal bag
10 closed.
[0036] FIG. 6 illustrates a membrane 28 employed on a bag 10. A
plurality of ribs 36 (as shown in FIG. 5) on outer surface 32 of
membrane 28 can be sealable to an inner surface 12a of front
surface 12 and to a top portion 20a of an inner surface 20b of
gussets 20. A plurality of ribs 36 on outer surface 32 of membrane
28 can be sealable to an inner surface 14a of rear surface 14 and
to a top portion 20a of an inner surface 20b of gussets 20. When
membrane 28 is sealed to bag 10, the seal can seal to the top
portion 20a of gussets 20 as well as front and back surfaces 12 and
14. Such a seal can be accomplished by methods commonly known in
the art, such as, for example, heat sealing.
[0037] When the article of manufacture is being manufactured, bag
10 can be formed, the top portion thereof open. Ribs 36a of outer
surface 32 of membrane 28 can then be sealed to inner surface 12a
of front surface 12 and top portions 20a of gussets 20. The bag 10
can be filled, and then ribs 36b of outer surface 32 can be sealed
to inner surface 14a of rear surface 14 and top portions 20a of
gussets 20 to seal bag 10 closed and form top surface 22.
[0038] Such a closure allows for top filling of bags. However, such
a closure could also be completely sealed at the top of the bag,
and form the top surface 22, before filling and be used with a
bottom fill process without having the closure break or burst
during the bottom fill process.
[0039] Although membrane 28 provides excellent burst resistance, a
tear strength of greater than about 15 pounds per square inch
proves difficult for a user to open by hand. Because it can be
desired that the article of manufacture of the present invention
also be easy for an ultimate consumer or user to open by hand,
membrane 28 comprises a targeted opening region 38. Targeted
opening region 38 can have a tear strength, measured in the
transverse or cross machine direction by ASTM Method D-882, of from
about 1 to about 15 pounds per square inch, alternatively of from
about 3 to about 12 pounds per inch, alternatively from about 4 to
about 10 pounds per inch, alternatively from about 4 to about 9
pounds per inch, and alternatively from about 5 to about 7 pounds
per inch.
[0040] During development of the bags of some embodiments of the
present invention, it was found that known non-reusable closures
and tamper evident features have opening regions that extend the
entire length of the membrane, i.e. essentially the entire width of
the bag. Such opening regions typically consist of one or more
score lines, perforations, or other material-weakening features.
However, it was found that such opening regions, while being easily
opened by a consumer, by hand, also can become a region of weakness
and bursting when bags filled with for example, 15 or more pounds
of dry pet food, are dropped, sometimes from as low as 18 inches.
Such drops are common in the shipping and handling of large, heavy
bags containing various particulate, flowable compositions and
cause damage and loss of product, and annoyance to retailers and
consumers.
[0041] Therefore, the burst-resistant bag 10 of one embodiment of
the present invention comprises targeted opening region 38 that
comprises from about 1% to about 90% of a length L of membrane 28.
Alternatively targeted opening region 38 comprises from about 1% to
about 50% of the length L of membrane 28, alternatively from about
1% to about 30% of the length L of membrane 28, and alternatively
of from about 1% to about 10% of the length L of membrane 28.
Furthermore, it was found that when the opening region extends to,
or is located within, about 5% of either end 28a, 28b of the length
L of membrane 28, even if the opening region only comprises a small
percentage, for example about 10-20%, of the length L of membrane
38, burst resistance is decreased. Thus, even small opening
regions, when located at the end(s) 28a, 28b, of membrane 28,
decrease burst resistance. Therefore, the "targeted opening region"
38 of one embodiment of the present invention means, and has the
proviso that, the opening region does not extend to within about 5%
of either end 28a, 28b of membrane 28. Targeted opening region 38
can be located anywhere along the length L of membrane 28, within
the definition of the targeted opening region, or can be centered
at a midpoint M along the length L of membrane 28 and width W of
bag 10. Targeted opening region 38 can be located at or near a
midpoint m of the width w of membrane 28 and can be disposed
inboard a distance from top edge 34 of bag 10. FIGS. 7a-c
illustrate various locations and sizes of one embodiment of
targeted opening region 38.
[0042] As can be seen in FIGS. 7a-c, targeted opening region 38 can
comprise a plurality of perforations 40 in membrane 28. Targeted
opening region 38 can also comprise and be formed by laser scoring,
heat scoring, or mechanical weakening of any type such as removing
a portion of material.
[0043] Also shown in FIGS. 7a-c, membrane 28 can also comprise
instructional indicia 42 on user-facing surface 30 of membrane 28.
Such instructional indicia 42 can comprise printing including
words, pictures, symbols, illustrations, and the like, to indicate
to the user where and how to open the non-reusable closure 26.
[0044] Membrane 28 can be formed from a material selected from the
group consisting of ethylene derived polymer, polypropylene,
polyester, polyolefins, homopolymer and/or co-polymer polyolefins,
and combinations thereof. Particularly, membrane 28 can comprise an
ethylene-derived polymer selected from the group consisting of low
density polyethylene, high density polyethylene, ultra-low density
polyethylene, and combinations thereof. The particular combination
of material can be selected based on balancing strength of the
material for burst resistance with openability for ease of use of
the bag 10. The material can be devised and formed based on its
ability to seal securely to the plastic laminate of bag 10 to
provide the required seal strength of at least about 1,600 pounds
per square inch. The material of the membrane can be a co-extruded
blend of low density polyethylene, high density polyethylene, and
ultra low/very low density polyethylene, with ultra low/very low
density polyethylene forming ribs 36 and 36 such that the ribs seal
to the inner surfaces of the bag at a temperature that can be less
than about 68.degree. C. The number of ribs 36 can depend on the
width w of the membrane. The spacing of the ribs 36 on membrane 28
can depend on the type and strength of seal desired.
[0045] In addition to finding a particular material for the
membrane 28 that provides burst resistance and allows for
openability, the dimensions of membrane 28 can be important with
respect to burst resistance, seal strength, ease of sealing during
manufacturing, and openability. Membrane 28 can have a width w of
from about 1.5 inches to about 3 inches. Alternatively, membrane 28
can have a width of from about 2 inches to about 3 inches.
Alternatively, membrane 28 can have a width of about 3 inches. When
the total width w of the membrane 28 is about 3 inches, there can
be about ten to fifteen (10-15), alternatively about fourteen (14)
ribs 36 on outer surface 32, as illustrated previously in FIG.
5.
[0046] Production and creation of the particular plastic laminate
can be advantageous such that when the laminate is used for bags
that contain particulate, flowable compositions are often dropped
during shipping and handling. Conventional, commercially available
such bags often burst when dropped from a height of as low as 18
inches, when filled with as little as 15 pounds of composition.
Such bursting causes damage and lost product as well as messes and
annoyance to retailers and consumers. In particular, bags that have
reclosable features tend to burst at the site of the reclosable
feature. Thus, currently available resealable feed bags are
generally not available in capacities greater than about 15 pounds,
and/or have the reclosable feature taped over, or otherwise
additionally reinforced.
[0047] When bags containing large amounts, such as the amounts
disclosed herein, such as up to 75 pounds or up to 75 liters, of
particulate, flowable compositions burst, several elements of the
bag can fail. If the bag has a reclosable feature, the forces
generated by a drop of the bag can cause the composition contained
therein to burst through the reclosable feature. The seals that
form the bag can separate and fail. The material from which the bag
itself is made, for example, the plastic laminate, can tear or
burst open. The material from which the laminate is made, as well
as the thickness of the laminate affect its burst resistance.
[0048] Therefore, in some embodiments of the present invention it
can be advantageous to create an appropriate laminate having a
balance of strength and stretchability (measured by tensile
strength), flexibility and stiffness (measured by secant modulus),
texture, thickness, and cost-effectiveness. Particular laminates
may have a high tensile strength, and therefore a high resistance
to stretching, which can be useful. However, in some instances,
such a laminate may be brittle or stiff (i.e. have a high secant
modulus), and because it resists stretching, may burst easily and
therefore may not be useful or particularly preferred in some bags
of the present invention. In addition, a laminate usable with
embodiments of the present invention can also have a suitable
texture and not be extremely slippery. Bags containing at least
about 15 pounds of a particulate, flowable composition can be
difficult to pick up and carry because of the weight of material
contained therein, especially when the materials used for
construction of the bag are slippery or difficult to grip. Thus,
bags containing such materials should ideally not be slippery or
difficult to grip.
[0049] In addition, the laminate can be securely sealable to form
the bag by methods known the art such as heat sealing. The laminate
can be cost-effective as well, and plastic laminate bags are more
costly than traditional paper feed bags. Thus, in one embodiment,
as thin a layer of laminate as possible can be used from a
cost-effective standpoint. However, the thickness of the laminate
in combination with its composition affects its likelihood to burst
if dropped. Thus, material composition and thickness can also be
considered.
[0050] Bag 10 of embodiments of the present invention can have a
seal strength of at least about 1,600 pounds per square inch as
measured by ASTM Method D-882. Alternatively, bag 10 can have a
seal strength of at least about 1,800 pounds per square inch.
[0051] The plastic laminate forming the bag can have an impact
dart-drop resistance of at least about 5 grams/mil as measured by
ASTM Method D-1709-04, and a tear resistance of at least about 6
grams/mil and 9 grams/mil as measured in both the machine direction
(MD) and transverse or cross machine direction (CD), respectively,
by ASTM Method D-1922. Alternatively, the plastic laminate can have
an impact dart drop resistance of at least about 5.5 grams/mil and
a tear resistance of at least about 7 grams/mil (MD) and about 10
grams/mil (CD). Alternatively, the plastic laminate can have an
impact dart drop resistant of at least about 6.2 grams/mil and a
tear resistance of at least about 7.9 grams/mil (MD) and 10.8
grams/mil (CD).
[0052] The plastic laminate of the bag can have a secant modulus of
from about 30,000 to about 110,000 pounds per square inch, as
measured in both the machine and transverse or cross machine
directions by ASTM Method D-882.
[0053] Bag 10 can be formed from a plastic laminate selected from
the group consisting of ethylene-derived polymer, polypropylene,
polyester, teraphthalates, polyolefins, homopolymer and or
co-polymer polyolefins, woven polypropylene, ployamides, and
combinations thereof. More particularly, the plastic laminate can
be selected from the group consisting of ethylene-derived polymers
such as polyethylenes in combination with a polyamide, such as
Nylon 6,6. In order to be sealable to itself and to the material of
a non-reusable closure, if one is employed, the material of the
inner surface of the laminate can have a relatively low melting
point such that it melts to enable heat sealing, whereas the outer
surface can have a higher melting point such that it does not melt
during heat sealing. Thus, an outer layer can be Nylon 6,6, and an
inner layer can be a co-extruded blend of linear low density
polyethylene, medium density polyethylene, and linear low density
polyethylene. As used herein the densities of polyethylene, "low",
"medium", "high", "ultra low/very low", have meanings as used and
understood in the art for such materials.
[0054] In another embodiment, the laminate can be a multi-layer
laminate. The multi-layer laminate can include many layers, such as
an inner layer and an outer layer, and even more layers. In one
embodiment, the multi-layer laminate can comprise a 75 gauge cast
F101 Nylon outer layer and a 6.1 mil PE coex (polyethylene) inner
layer. The plastic laminate can have a thickness of from about 130
to about 200 microns. Alternatively, the plastic laminate can have
a thickness of from about 140 to about 170 microns.
[0055] In some embodiments, such a laminate can provide other
beneficial properties. This multi-layer laminate can assist in
reducing damage to the bag but can still provide a relatively high
gloss, high print quality, reclosable, resealable bag than can
stand up, as disclosed herein.
[0056] In addition to aiding in enabling bag 10 to be
burst-resistant in one embodiment, the plastic laminate can provide
oxygen and moisture barrier properties. It has been shown that
plastic can be a better oxygen and moisture barrier than
traditional paper for pet foods. It has also been shown that fats,
carbohydrates, proteins, and other components commonly found in pet
foods oxidize over time when exposed to air. Furthermore, it has
been shown in some palatability tests that animals prefer, over
time, food stored in plastic bags versus that stored in paper bags
but not always. Thus, the articles of manufacture of embodiments of
the present invention can in some embodiments also provide enhanced
palatability of the oxidizable compositions contained therein.
[0057] Therefore, in one embodiment a plastic laminate can have an
oxygen transmission rate of less than about 6.5 cc/100 in.sup.2/24
hours, as measured by ASTM Method D-3985, and alternatively of less
than about 6.2 cc/100 in.sup.2/24 hours. A plastic laminate can
also have a moisture vapor transmission rate of less than about 0.1
grams/100 in.sup.2/24 hours, when measured by ASTM Method F-1249,
and alternatively of less than about 0.8 grams/100 in.sup.2/24
hours.
[0058] In another embodiment of the present invention, as shown in
FIGS. 1 and 2, bag 10 can further include a reusable closure 44. As
described above, the dimensions and proportions of bag 10 can be
such that they provide burst resistance and enhanced stability.
Thus, bag 10 can be stable when placed on bottom surface 16. The
plastic laminate also can provide oxygen and moisture barrier
properties to enable the composition to be stored in bag 10 over
time. Therefore, providing a reusable closure enables the end user
consumer to simply use bag 10 itself as the storage device for the
composition.
[0059] Non-limiting examples of reusable closures of the present
invention include a track and a slider system, a plastic zipper, a
metal zipper, a hook and loop fastening system, a threaded closure
device, a pressable sealing device, a snap sealing device,
resealable adhesive, magnetic sealing device, electrostatic sealing
device, and combinations thereof.
[0060] Reusable closure 44 can be disposed at top edge 34 of bag
10, as shown in FIGS. 1 and 2. Alternatively, reusable closure 44
can be disposable a distance inward from top edge 34 of said
bag.
[0061] In another embodiment of the present invention, bag 10 can
comprise both a non-reusable closure and a reusable closure. As
described above, bag 10 can be not only burst-resistant but stable
as well, such that it can be used as a reusable storage container.
As described above, the proportions and dimensions of bag 10 can
provide stability. Therefore, bag 10 can have a tip angle of from
about 10.degree. to about 50.degree., alternatively a tip angle of
from about 20.degree. to about 30.degree.. Tip angle is measured
using ASTM Method 6179.
[0062] Bag 10 can also be provided with features to equalize air
pressure within the bag, to assist in providing burst resistance,
and to provide an appealing visual appearance to the bag. However,
such features for equalizing air pressure can also prevent oxygen
transmission into the bag and infestation, i.e. prevent undesirable
organisms form entering the bag. One such feature can be a valve,
such as a one-way valve. Other such features are generally known to
those of ordinary skill in the art.
[0063] Air pressure equalization described the escape of and
entrance of air into and out bag 10. It can be important to allow
air to escape from bag 10 during shipping and handling of the bags.
When bags are stacked on pallets for shipping, the weight of the
bags on top of each other can cause the bags to burst if there is
no way for air to escape from the bags. However, once air is
squeezed out of the bags, the bags can have an unappealing, `vacuum
packed`, lumpy appearance. Thus, it can be desirable to allow air
back into the bags once the bags are unloaded for display and
sale.
[0064] Air pressure equalization can be accomplished by providing a
plurality of perforations 46 in at least one side of bag 10, for
example in each side gusset 20 as shown in FIGS. 1 and 2.
Perforations 46 can be less than about 150 micrometers in diameter,
alternatively less than about 100 micrometers in diameter, and
alternatively less than about 70 micrometers in diameter, in order
to allow air to pass there through but prevent infestation.
[0065] In addition, one or more gaps (not shown) can be provided at
a seal of the bag for additional passage of air. The gap(s) can be
formed by interrupting the heat sealing process, and such seals are
known in the art as "skip gap" seals. To form such a "skip gap
seal," a non-continuous seal bar can be used, i.e. a seal bar
having one or more gaps thereon wherein the gapped part of the seal
bar would not touch the material being sealed, thus leaving an
unsealed portion or "gap." Such a "skip gap seal" can be formed on
the seal formed at the bottom of the bag, at the seal formed when
attaching a first portion of the membrane to the front surface of
the bag, or when attaching the second portion of the membrane to
the rear surface of the bag. A "skip gap seal" can be formed, for
example in the final seal sealing the bag closed once it has been
filled. Each gap can be of from about 70 .mu.m to about 10 mm in
length. If no non-reusable closure is used, gap(s) can be formed in
any of the seals used to form the bag, as required for appropriate
desired air equalization.
[0066] The gap(s) can be straight sided and can have a cylindrical
or tubular shape or can be shaped and/or curved and of a length
that would still allow air to pass there through, but which would
provide a barrier to infestation (i.e. provide a longer, more
complicated path for potentially infesting organisms). Any shaped
gap can be incorporated or formed into the seal bar of the heat
sealing apparatus, as would be understood by those skilled in the
art.
Method of Enhancing Palatability
[0067] Embodiments of the present invention also can include
methods of enhancing palatability of an oxidizable particulate,
flowable composition after storage comprising the steps of: [0068]
a. providing a plastic laminate bag comprising: [0069] i.) two side
surfaces each having a gusset therein and connecting the front and
rear surfaces; [0070] ii.) a closure system comprising a reusable
closure and a non-reusable closure, wherein said non-reusable
closure comprises a membrane having a targeted opening region, the
targeted opening region having a tear strength of from about 4 to
about 10 pounds per square inch; [0071] wherein the plastic
laminate has a predetermined oxygen transmission rate and a
predetermined water vapor transmission rate; [0072] b. filling the
plastic laminate bag with at least about 15 pounds of an
oxidizable, particulate, flowable composition; [0073] c. sealing
the plastic laminate bag closed; thereby preventing oxidation and
spoilage and enhancing the palatability of the composition
contained therein.
[0074] The plastic laminate usable with the method can have an
oxygen transmission rate of less than about 6.5 cc/100 in.sup.2/24
hours, alternatively less than about 6.2 cc/100 in.sup.2/24 hours.
The oxygen transmission rate is measured, as described above, by
ASTM Method D-3985. The plastic laminate can have a moisture vapor
transmission rate of less than about 0.1 grams/100 in.sup.2/24
hours, alternatively less than about 0.8 grams/100 in.sup.2/24
hours. The moisture vapor transmission rate is measured, as
described above, by ASTM Method F-1249.
EXAMPLES
[0075] ASTM Method 5276-98 (Reapproved 2004) "Standard Test Method
for Drop Test for Loaded Containers by Free Fall" contains
provisions for dropping variously shaped containers to assess
various parameters such as finding an average drop height to
failure, or for attaining pass/fail data. Bags of the present
invention are subjected to these tests from heights of up to 6
feet, as a specification for shipping and handling
requirements.
[0076] See in particular sections A1.1, A1.3. When testing bags of
embodiments of the present invention, the test is a pass/fail test
because required drop heights are specified. Based on experience
packaging, shipping, and handling such bags, a specification is set
that such bags containing at least about 20 pounds of particulate,
flowable material, must pass a free fall drop from at least about 6
feet. When the bags contain at least about 40 pounds of
particulate, flowable material, they must pass a free fall drop
from at least about 4 feet. Failure occurs if any of the seals of
the bag, any closures (whether reusable or non-reusable), or the
bag material tears, splits, separates, punctures, deforms, bulges,
and/or leaks.
[0077] The apparatus used for such a drop conforms to section 5 of
ASTM Method 5276-98. Specifically the apparatus used is a L.A.B.
Model 160A Drop Tester. The bags can be dropped on each of the six
surfaces of the bag, and in particular must pass the drop test from
the given drop height on at least one of the side surfaces. Single
drops are performed, as in section A2.2.1, and drops on all six
surfaces are performed, as in section A2.2.8. In particular, drops
are performed on one or both of the two side surfaces, as in
section A2.2.10, because the two side surfaces are those determined
most likely to fail. The impact surface is concrete, as specified
in section 5.1.5.1, and complies with sections 5.1.5.3-5. When the
bags are dropped on each surface, they are dropped such that the
drop complies with sections 8.4.1-8.5.
Example 1
[0078] A bag of one embodiment of the present invention can be
constructed as follows.
[0079] A plastic laminate film, comprising a 12 micron thick layer
of polyethylene teraphthalate ("PET") bonded by adhesive lamination
to a 140 micron thick co-extruded layer of metallocene linear low
density polyethylene, medium density polyethylene, and metallocene
linear low density polyethylene, (available for example from
Exopack, Spartanburg, S.C., USA) is used for forming the bag. Once
the bag is formed, the co-extruded polyethylene layer forms the
inner surface and the PET layer forms the outer surface of the
bag.
[0080] The sides of the bag are gusseted. The two edges of each
side gusset on each side of the bag are sealed to form two edge
seals on each side, resulting in four edge (4) seals, thus forming
a "quad seal" bag. The bag is sealed at the bottom by conventional
heat sealing, capturing the bottom of the side gussets therein and
forming a bottom surface. The side gussets are also sealed at the
bottom of f the bag with a "K-seal" as is known in the art, to
allow the bottom surface to be flattenable. The side gussets are
also sealed at the top of the bag with a "K-Seal", as is known in
the art, to restrict the flow of air through the connection of the
gusset to the front and back panels.
[0081] A non-reusable closure membrane formed from a blend of low
density polyethylene and ultra low density polyethylene is
attached, by co-extrusion therewith, to a track of a slider and
track zipper, for example a Slide-Rite.RTM. zipper from Pactive
Corp., Lake Forest, Ill., USA. A track of a slider track zipper
device is formed high density polyethylene. The track and the
membrane are co-extruded. The membrane has a width w of about 3
inches as measured from inner edge to inner edge of the track. The
membrane has a targeted opening region of 1.5 inches in length,
disposed along the length of the membrane, and formed form a
plurality of perforations. The targeted opening region is formed
centered at a midpoint m of the width w of the membrane, and
centered at a midpoint M of the length L of the membrane. See FIG.
7C. The targeted opening region has a tear strength (as measured by
ASTM Method D-882) of between about 5-7 pounds per square inch.
[0082] The non-reusable closure membrane attached to the reusable
track and slider closure is attached by heat sealing one side of
the outer surface of the membrane to an inner surface of the front
surface of the bag. The inner and outer surfaces of one half of
each side gusset are captured by the seal. The bag is filled with
20 pounds of dry pet food. With the dimensions described herein,
20% headspace is provided and results in 5.5 inches of bag height
remaining above the height of the product, which enables proper
sealing of the bag. The second side of the outer surface of the
membrane of the non-reusable closure is then heat sealed to the
inner surface of the rear surface of the bag to close the bag. The
inner and outer surfaces of the other half of each side gusset are
captured by the final seal.
[0083] The bag has a height of 25 inches, a width of 13.25 inches,
and a depth of 6.5 inches. Height dimensions have a tolerance of
about 0.12 inches. Width dimensions have a tolerance of about 0.25
inches. Depth dimensions have a tolerance of 0.6 inches. The ratio
of width to height is 0.6. The ratio of depth to height is
0.25.
[0084] A bag as described in this example will pass a drop test
conducted according to ASTM Method D-5276-98 (Reapproved 2004)
Standard Test Method for Drop Test of Loaded Containers by Free
Fall, when dropped on any and all six surface, particularly the two
side surfaces, from a height of 6 feet when filled with 20 pounds
of dry dog food.
Example 2
[0085] An alternative embodiment of a bag of an article of
manufacture of the present invention can be made as follows.
[0086] A plastic laminate film, comprising a 19 micron thick layer
of Nylon 6,6 bonded by adhesive lamination to a 155 micron thick
co-extruded layer of metallocene linear low density polyethylene,
medium density polyethylene, and metallocene linear low density
polyethylene, (available for example from Exopack, Spartanburg,
S.C., USA), is used for forming the bag. Once the bag is formed,
the co-extruded polyethylene layer forms the inner surface and the
nylon layer forms the outer surface of the bag.
[0087] The sides of the bag are gusseted. The two edges of each
side gusset on each side of the bag are sealed to form two edge
seals on each side, resulting in four edge (4) seals, thus forming
a "quad seal" bag. The bag is sealed at the bottom by conventional
heat sealing, capturing the bottom of the side gussets therein and
forming a bottom surface. The side gussets are also sealed at the
bottom of the bag with a "K-seal" as is known in the art, to allow
the bottom surface to be flattenable. The side gussets are also
sealed at the top of the bag with a "K-Seal" as is known in the
art, to restrict the flow of air through the connection of the
gusset to the front and back panels.
[0088] A non-reusable closure membrane formed from a blend of low
density polyethylene and ultra low density polyethylene is
attached, by co-extrusion therewith, to a track of a slider and
track zipper, for example a Slide-Rite.RTM. zipper from Pactive
Corp., Lake Forest, Ill., USA. A track of a slider track zipper
device is formed high density polyethylene. The track and the
membrane are co-extruded. The membrane has a width w of about 3
inches as measured from inner edge to inner edge of the track. The
membrane has a targeted opening region of 1.5 inches in length,
disposed along the length of the membrane, and formed form a
plurality of perforations. The targeted opening region is formed
centered at a midpoint m of the width w of the membrane, and
centered at a midpoint M of the length L of the membrane. See FIG.
7C. The targeted opening region has a tear strength (as measured by
ASTM Method D-882) of between about 5-7 pounds per square inch.
[0089] The non-reusable closure membrane attached to the reusable
track and slider closure is attached by heat sealing one side of
the outer surface of the membrane to an inner surface of the front
surface of the bag. The inner and outer surfaces of one half of
each side gusset are captured by the seal. The bag is filled with
40 pounds of dry pet food. With the dimensions described herein,
20% headspace is provided and results in 5.5 inches of bag height
remaining above the height of the product, which enables proper
sealing of the bag. The second side of the outer surface of the
membrane of the non-reusable closure is then heat sealed to the
inner surface of the rear surface of the bag to close the bag. The
inner and outer surfaces of the other half of each side gusset are
captured by the final seal.
[0090] The bag has a height of 29 inches, a width of 17.5 inches,
and a depth of 7.25 inches. Height dimensions have a tolerance of
about 0.12 inches. Width dimensions have a tolerance of about 0.25
inches. Depth dimensions have a tolerance of 0.6 inches. The ratio
of width to height is 0.6. The ratio of depth to height is
0.25.
[0091] A bag as described in this example will pass a drop test
conducted according to ASTM Method D-5276-98 (Reapproved 2004)
Standard Test Method for Drop Test of Loaded Containers by Free
Fall, when dropped on any and all six surfaces, particularly the
two side surfaces, from a height of 4 feet when filled with 40
pounds of dry dog food.
[0092] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0093] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that any meaning or definition of a term in this document
conflicts with any meaning or definition of the same term in a
document incorporated by reference, the meaning or definition
assigned to that term in this document shall govern.
[0094] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *