Note: Descriptions are shown in the official language in which they were submitted.
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FLEXIBLE BAG CONTAINING UNIT DOSE ARTICLES
FIELD OF THE INVENTION
The field of the present invention is packaging for unit dose articles,
particularly unit dose
articles comprising laundry compositions. The laundry compositions may
include, but are not limited
to, additives for use in wash and/or rinse cycles, detergents, fabric
softeners, and perfumes among
others. These unit dose articles may comprise compositions that are in any
suitable form including,
but not limited to, solids, pastes, gels, liquids and combinations thereof.
Non-solid laundry
compositions will most commonly be encapsulated in film material that is at
least partially soluble in
water.
BACKGROUND OF THE INVENTION
Life is becoming more hectic than ever. We now access global information at
the touch of a
button, keep our mobile phones handy for any eventuality, and as consumers, we
have become
accustomed to the get-it-now life style. Household compositions like
detergents have been impacted
by this trend. For example, over the last decade and a half manufacturers have
moved from the
traditional big-box laundry and auto dish detergents, to compacted detergents,
and more recently, to
unit dose detergents. The unit dose is typically a tablet or a water soluble
pouch that can be directly
added into a washing machine, without the bother or mess of measuring. The
unit dose is designed
to dissolve in the water during the wash cycle.
Water-soluble unit dose articles are susceptible to incidental or
unintentional contact with
moisture. Consequently, it is important to protect the article from moisture
during the various
stages of its life cycle, including during transport and storage. Packaging is
a way of providing such
protection. Packaging also forms an integral part of a product and may be a
consumer's first point of
contact with a brand. Thus apart from protecting the unit dose article from
damage, the package
must be aesthetically pleasing and provide space for branding and usage
information to the
consumer. In sum, the ideal package is functional, informative and attractive.
One attempt to meet these needs has been to package unit dose articles in
flexible bags. To
prevent waste and to provide a full looking bag, the bags are typically sized
according to the volume
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of unit dose articles contained therein. The height of the bag is often
manipulated to provide for a
good shelf presence. The width of the bag is often manipulated to minimize the
bag footprint on the
shelf. Oftentimes, these considerations lead to a tall bag having a small
footprint and consequently a
high center of gravity. These bags may tend to tip over on the store shelf.
Some bags have a window through which the consumer may see the product prior
to
purchase. The size and placement of the window is such that the bag appears to
be full of product.
A full looking bag has been viewed as a critical element for conveying to
consumers that they are
getting their money's worth.
Given these considerations, as well as that unit dose articles are sold in a
variety of counts,
the manufacturer may be required to make a whole series of bags for a single
final product. This can
be disadvantageous since it adds to manufacturing costs.
Thus there remains a need for an attractive bag that: protects unit dose
articles from moisture;
provides the consumer with brand and usage information, and that can be
utilized to package a
variety of article counts, while still signaling to the consumer that they are
getting value for their
money. Such a bag must also comprise a combination of bag dimensions that
collectively meet
these needs while providing for good process reliability.
SUMMARY OF THE INVENTION
The present invention is directed to a flexible sealed bag containing a
plurality of unit dose
articles. The flexible sealed bag contains at least one at least partially
water soluble unit dose article
having a major dimension. The flexible bag comprises a front panel and a back
panel marginally
joined thereto along at least two opposed edges to be in a confronting
relationship to form a closed
bag. The front panel and the back panel are joined at the top by a frangible
seal. A bottom panel is
intermediate to the front panel and the back panel, and joined to each of
them. The bag has a depth
that is at least about two times that of the major dimension of the at least
one unit dose article.
The invention is also directed to a series of these bags, which each have a
height less than
about 300 mm and each differ in height by about 20 to about 30 mm.
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BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly
claiming the invention, it is believed that the present invention will be
better understood from the
following description of preferred embodiments taken in conjunction with the
accompanying
drawings in which:
FIG. 1 is a perspective view of a bag containing articles according to the
present invention.
FIG. 2 is a frontal view of an empty bag according to the present invention.
FIG. 3 is a perspective view of a unit dose article according to the present
invention.
FIG. 4 is a cross-sectional view of a chute through which unit dose articles
of the present
invention may fall.
FIG. 5 is a perspective view of a bag according to the present invention under
a chute.
FIGS. 6a, 6b and 6c are frontal views of bottom seals according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of a flexible bag 10 according to the present invention is as
illustrated in
FIG. 1. The flexible bag 10 comprises a front panel 30, a back panel 50 and a
bottom panel (not
shown). The front panel 30 in this embodiment is rectangularly shaped and
comprises spaced apart
side edges 35a, 35b. The front panel is marginally joined to the back panel 50
along at least two
opposed edges to be in confronting relationship. FIG. 1 shows the two opposed
edges marginally
joined together, those opposed edges of the front panel and back panel,
respectively 35a, 55a. The
bottom panel (not shown) is intermediate to the front panel 30 and back panel
50, and joined to each.
The front panel 30 and the back panel 50 are joined at the top by a frangible
seal 20 after the bag is
filled with unit dose articles.
A variety of materials can be used to form the panels of the bag, the seal(s)
and other
elements of the present invention. Technical requirements such as moisture
protection and
compatibility with product as well as costs and ease of manufacture are the
primary factors when
selecting these materials.
One or more materials may be used to form the one or more panels 30, 50 of the
bag 10. In
some embodiments, one or more panels 30, 50 comprise layers of material. In
some embodiments,
the layers are laminated together. Materials of use include, but are not
limited to film forming
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plastics. Film forming plastics may be selected from the group of polyethylene
terephthalate,
polyethylene, NylonTM, BarexTM, EvohTM and combinations thereof. In some
embodiments, the
panels 30, 50 may comprise layers laminated together.
The panels 30, 50 of the bag 10 may be joined along the edges 35a, 35b using
any suitable
method that will provide a seal that serves as a moisture barrier. Non-
limiting examples include heat
sealing, ultrasonic welding, autogeneous bonding, pressure sealing, adhesive
sealing, and
combinations thereof.
Any suitable means of creating a frangible seal joining the front and back
panels together is
of use. Non-limiting examples include perforating, applying a line of
weakness, peelable seal,
reasealable closures and combinations thereof.
As shown in FIG. 1, the front panel 30 may comprise at least one opaque
portion 31 and at
least one transparent window 32. The unit dose articles 100 are distributed
from the bottom of the
bag 10 to a height 110 therein, providing an empty space 33 above the height
110 of the unit dose
articles 100 such that the transparent window 32 intercepts the articles 100
and the empty space 33.
The flexible bag 10 shown in FIG. 1 comprises an optional, additional closure
25 for securing the
bag 10 in a closed condition after the frangible seal 20 is broken.
Referring to FIG. 2, the flexible bag 10 may be defined by its height 11 and
width 12 when
the bag 10 is unfilled and placed on a flat surface with the front panel up.
The height 11 and width
12 of the bag 10 are measured at their maximum value.
FIG. 3 shows an exemplary unit dose article 100 of the present invention. The
unit dose
article 100 is preferably a unitized dose of a household care composition
including, but not limited to
laundry, dish or hard surface cleaning compositions. While such articles 100
can have a variety of
forms, shapes and compositions, a common feature of such additives is their
susceptibility to being
degraded, deactivated, rendered unstable or dissolved when exposed to
prolonged and/or high levels
of moisture. By way of example, laundry additives encapsulated in polymer
films that are designed
to be fast dissolving under both hot and cold water conditions, may become
tacky, unstable and even
prematurely dissolved if not protected from prolonged exposure to atmospheric
moisture. Such
articles are described in U.S. Patent Publication No. 2010/0192986A1 and U.S.
Patent No. 6995126,
which are incorporated herein by reference.
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As shown in FIG. 3, the unit dose article 100 may have a pincushion shape with
a major
dimension 101. As used herein, "major dimension" defines the largest linear
dimension of the
largest unit dose article 100 in the bag. If the unit dose article 100 is
substantially circular, the
"major dimension" defines the diameter thereof. In embodiments in which the
bag 10 contains a
plurality of unit dose articles 100 having different shapes and sizes, the
major dimension 101
corresponds to the major dimension of the largest of the unit dose article
100.
In preferred embodiments, the unit dose article has a pincushion shape with a
major
dimension of no greater than about 50mm.
The bags of the present invention are filled with a pre-determined quantity of
unit dose
articles along a high speed line using any suitable method in the art. Non-
limiting methods include
Vertical Form Fill Sealing, Horizontal Form Fill Sealing and Horizontal Fill
Sealing.
In any one or more of these processes, unit dose articles may be dispensed
through a chute
that directs the unit dose through an opening in the bag. In some embodiments,
the opening is at the
top of the bag, in other embodiments, the opening is at the side of the bag.
Once the bag is filled, the
opening may be sealed. The filling and sealing processes typically occur at
line speeds as high as 60
bags per minute. Consequently, process reliability is one key to reducing down
time on the line.
Process reliability may be impacted by several factors such as the chute
geometry and bag
geometry. One factor to consider is that as unit dose articles are dispensed
from a chute into a bag,
they tend to form a mound inside of the bag. If the height of the mound is too
great, it can interfere
with the subsequent sealing of the bag, which can in turn lead to breakage of
the article and
contamination of the line.
Another factor to consider is that as the unit dose articles fall through the
chute, they can
bunch up or "bridge" such that they clog the chute and impede further unit
dose articles from being
dispensed into the bag. Oftentimes, this problem leads to inconsistencies in
the quantity of unit dose
articles contained within the bags when they are sealed.
For these and other reasons, the dimensions of the chute are chosen to
minimize bridging.
The minor dimension of the chute is chosen to be at least about two times that
of the major
dimension of the largest unit dose article to be packaged in the bag. Fig. 4
shows the cross-section
of an exemplary chute 700. The minor dimension 710 of the chute is the
diameter of a theoretical
circle 711 inscribed within a cross-section of the chute at the narrowest
point along the chute's
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height. In some embodiments, the cross-section of the chute, particularly at
its opening, may be
congruent with the cross-section of the fill side of the bag. In other
embodiments, the chute opening
may smaller than the cross-section of the fill side of the bag.
The dimensions of the bag may impact process reliability as well as shelf
presence.
Consequently, a combination of bag dimensions is chosen to maximize shelf
presence, whilst
minimizing interruptions in the production line. These dimensions are
discussed in further detail
below.
Bag Depth:
As unit dose articles fall from the chute into the bag, bridging can occur at
the opening of the
bag. Consequently, the front panel to back panel dimension or "depth" of the
bag at its opening
during filling is chosen to minimize bridging. Referring to Fig. 5, the depth
13 of the bag 10 at its
opening 15 is defined as the maximum distance between the front panel 30 and
the back panel 50
when the bag is set to be filled with unit dose articles from a chute 700.
It has been found that bags having a bag opening depth that is at least two
times the major
dimension of the largest unit dose article provide for good process
reliability. As discussed above,
preferred unit dose articles according to the present invention may have a
major dimension that is no
greater than about 50 mm. Thus the depth of the preferred bag is at least two
times that, or at least
about 100 mm.
Bag Height
Bag height is typically chosen to provide for good presence on a store shelf.
It has been
found that bag height may allow ready differentiation by the consumer between
bags containing
different quantities of unit dose articles. Maximum bag height is often a
function of store shelf
height. Shelf height (i.e., the vertical distance between the top of a shelf
and the bottom of the shelf
directly above it) is often about 300mm. Thus if different quantities of a
unit dose article are to be
sold, a series of bags having different heights, each less than 300 mm are
utilized.
It has been found that for the differences in height to be readily apparent to
the consumer, the
minimum height step between the bags is at least about 20 mm. Thus bags
according to the present
invention may be chosen from a "menu" of bags starting at 200 mm and
progressing upward to 300
mm in steps of 20 mm.
Aspect ratio
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The "aspect ratio" of a flexible bag is defined as the ratio between the bag
height and width.
A bag's aspect ratio may impact the bag's shelf presence and stability on the
shelf. Shelf stability is
quantified by a bag's tip angle. "Tip angle" is defined herein as the maximum
angle that the vertical
axis of the package can make with an imaginary vertical line before the bag
falls over. The angle is
measured by progressively tilting the package until it falls over. The package
can be tilted sideways,
front to back or in any other direction of interest. In this application we
measure the tilt angle front to
back as this represents the least stable direction of the bags.
For a given depth, a bag having a high aspect ratio will have a high center of
gravity. A high
center of gravity may in turn result in a reduced tip angle. A bag having the
same depth, but a lower
aspect ratio will have a lower the center of gravity and increased the tip
angle. Thus the bag having
the lower aspect ratio is more stable on the shelf.
However, the shelf stability of the flexible bag is desirably balanced with a
good shelf
presence. In the laundry and auto dish product categories, the flexible bags
are typically tall and
narrow. Thus a short and wide bag would likely not fit with this aesthetic.
Balancing these considerations, it has been found that the optimal aspect
ratio of a flexible
bag is from about 1:1 to about 1.3: 1, the later aspect ratio being most
preferred.
Bag Width
For a given height and depth there is a minimum bag width that ensures that
the internal
volume is sufficient to fit the contents in a reliable manufacturing
operation. In other words, there is
a minimum bag width that ensures that no unit doses will be crushed by the bag
sealing operation
causing contamination and line stoppage. The minimum width may be determined
using a testing
fixture in the lab that mimics the filling equipment on the high speed line.
Once the height and aspect ratio of the flexible bag are chosen, the width of
the bag may be
calculated as follows: Bag width = Bag height / Aspect Ratio
Bag Head Space/Fill Levels
The fill level percentage and the headspace percentage of a flexible bag are
calculated as fill
height / bag height and headspace height / bag height, wherein
Fill height + Headspace height = Bag height.
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The headspace required depends on a variety of factors including, but not
limited to, the bag
dimensions, unit dose dimensions, coefficient of friction, puffiness and
filling equipment design.
The flexible bag according to the present invention is designed to minimize
the head space that is
needed for process reliability.
Fill levels of the flexible package according to the present invention are
within a range of
from about 28 to about 45% percent of the bag height, or within a range of
from about 32 to 45% of
the bag height. Most commonly, the fill level is about 35% of the bag height.
Bottom Seals
Referring to Fig. 6a, b and c, there are three common types of bag 10 bottom
seals 900: the
parabolic seal (Fig. 6a), the delta seal (Fig. 6b) and the square seal (Fig.
6c). As noted above, the
shelf stability of the flexible bag may be quantified by its tip angle. Thus
one skilled in the art could
choose a bottom seal that provides for the highest tip angle and consequently
the best shelf stability.
Within the category unit dose laundry and dish products, it has been found
that commercially
available bottles and bags have a tip angle between about 20 and 30 degrees.
Thus the bags
according to the present invention desirably have a tip angle of at least
about 20 . The square seal in
combination with a depth of at least about 100 mm provides the flexible
packages according to the
present invention with this desirable tip angle.
The flexible bags according to the present invention may further comprise
optional
components including, but not limited to, windows, resealable closures and
perfume.
Referring back to Fig. 1, in some embodiments, the flexible bag 10 may further
comprise
one or more transparent or translucent windows 32 through which the consumer
can see the fill line
of the unit dose articles 100 when the bag 10 is displayed to the consumer for
purchase at the point
of purchase. Useful window configurations are disclosed in the co-pending US
Patent Application
having Attorney Docket Number 11880 and filed on September 20, 2010.
The flexible bags according to the present invention may comprise more than
one seal. For
example, if the bag is sealed with a frangible seal, it may further comprise a
resealable seal so that
the consumer may sealably close the bag after use.
The flexible bags may further comprise perfume. The perfume may be applied to
the interior
of the bag using any suitable means. A non-limiting example is the application
of an adhesive strip
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comprising perfume to the interior of the bag. Useful adhesive perfume strips
are found n US Patent
Number 7304025 and US Publication Number 2008/0081774A1.
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."
Every document cited herein, including any cross referenced or related patent
or application,
is hereby incorporated herein by reference in its entirety unless expressly
excluded or otherwise
limited. The citation of any document is not an admission that it is prior art
with respect to any
invention disclosed or claimed herein or that it alone, or in any combination
with any other reference
or references, teaches, suggests or discloses any such invention. Further, 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.
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.
