U.S. patent application number 12/050426 was filed with the patent office on 2009-09-24 for compaction package.
Invention is credited to Kevin Lin.
Application Number | 20090238498 12/050426 |
Document ID | / |
Family ID | 41089020 |
Filed Date | 2009-09-24 |
United States Patent
Application |
20090238498 |
Kind Code |
A1 |
Lin; Kevin |
September 24, 2009 |
Compaction Package
Abstract
Provided is a compaction package that includes a flexible film
portion and a heat shrink film portion coupled to part of the
flexible film portion. The compaction package has a bottom, a
sidewall, and an open top that together define a hollow interior
space adapted to receive and contain a granular material. In a
first configuration prior to exposure to a heat source sufficient
to raise the temperature of the compaction package to a certain
critical heat shrink temperature, the interior space of the
compaction package has a first volume. In a second configuration
after exposure to the heat source, the interior space of the
compaction package has a second volume that is less than the first
volume.
Inventors: |
Lin; Kevin; (Berkeley,
CA) |
Correspondence
Address: |
THE CLOROX COMPANY
P.O. BOX 24305
OAKLAND
CA
94623-1305
US
|
Family ID: |
41089020 |
Appl. No.: |
12/050426 |
Filed: |
March 18, 2008 |
Current U.S.
Class: |
383/105 |
Current CPC
Class: |
B65D 75/002 20130101;
B65D 75/28 20130101 |
Class at
Publication: |
383/105 |
International
Class: |
B65D 33/00 20060101
B65D033/00 |
Claims
1. A compaction package comprising: a flexible film portion; a heat
shrink film portion coupled to said flexible film portion; wherein
said flexible film portion and said heat shrink film portion define
a container adapted to contain a granular material, said container
having a bottom, a perimeter wall, and an open top.
2. The compaction package according to claim 1 wherein said heat
shrink film portion is coupled to said flexible film portion by a
coupling means selected from the group consisting of adhesive and
heat welding.
3. The compaction package according to claim 1 wherein said bottom
is rectangularly shaped.
4. The compaction package according to claim 1 wherein said bottom
is circularly shaped.
5. The compaction package according to claim 1 wherein said heat
shrink film portion is biased to shrink in a transverse direction
across said heat shrink film portion when said compaction package
is heated to a critical heat shrink temperature.
6. The compaction package according to claim 1 wherein said heat
shrink film portion is biased to shrink in a longitudinal direction
along said heat shrink film portion when said compaction package is
heated to a critical heat shrink temperature.
7. The compaction package according to claim 1 wherein said heat
shrink film portion is biased to shrink in both a transverse
direction across said heat shrink film portion and in a
longitudinal direction along said heat shrink film portion when
said compaction package is heated to a critical heat shrink
temperature.
8. The compaction package according to claim 1, wherein said heat
shrink film portion is configured in a shape selected from the
group consisting of rectangular, isosceles trapezoidal, and "T"
shaped said "T" shaped shrink film portion having a vertical part
and a horizontal part.
9. The compaction package according to claim 1 wherein said heat
shrink film portion comprises a film selected from the group
consisting of polyolefine, polyvinyl chloride (PVC), and
polyethylene terephthalate glycol (PETG)
10. The compaction package according to claim 1 wherein said
perimeter wall comprises: a front coupled to a first sidewall; a
back coupled to said first sidewall and coupled to a second
sidewall opposing said first sidewall, said second sidewall being
coupled to said front.
11. The compaction package according to claim 10 wherein said heat
shrink film portion is coupled to said flexible film portion at one
or more of said front, back, first side, and second side.
12. The compaction package according to claim 10 wherein said
shrink film portion is coupled to said flexible film portion at one
or more side corner edges where said front couples to said first
sidewall, said back couples to said first sidewall and couples to
said second sidewall and where said second sidewall couples to said
front.
13. The compaction package according to claim 1, wherein said
flexible film portion includes one or more discontinuous parts, and
wherein said heat shrink film portion is interposed between and
coupled to edges of said one or more discontinuous parts of said
flexible film portion.
14. A compaction package comprising: a flexible film portion; a
heat shrink film portion coupled to said flexible film portion,
wherein said heat shrink film portion is biased to shrink in a
transverse direction when said compaction package is heated to a
critical heat shrink temperature; wherein said flexible film
portion and said heat shrink film portion define a flexible
container adapted to contain a granular material and having a
bottom, a perimeter wall, and an open top; and wherein said
compaction package has a first configuration prior to exposure of
said compaction package to a heat source and a second configuration
after exposure of said compaction package to said heat source, said
second configuration of said compaction package having a volume
that is less than the volume of said first configuration of said
compaction package.
15. The compaction package according to claim 14 wherein said heat
shrink film portion is configured in a shape selected from the
group consisting of rectangular, isosceles trapezoidal, and "T"
shaped said "T" shaped shrink film portion having a vertical part
and a horizontal part.
16. The compaction package according to claim 14 wherein said heat
shrink film portion is coupled to said flexible film portion by a
coupling means selected from the group consisting of adhesive and
heat welding.
17. A compaction package comprising: a flexible film portion; a
heat shrink film portion of rectangular shape and coupled to said
flexible film portion, wherein said heat shrink film portion is
biased to shrink in one or more of a transverse and a longitudinal
direction when said compaction package is heated to a critical heat
shrink temperature; wherein said flexible film portion and said
heat shrink film portion define a flexible container adapted to
contain a granular material and having a bottom, a perimeter wall,
and an open top; and wherein said compaction package has a first
configuration prior to exposure of said compaction package to a
heat source and a second configuration after exposure of said
compaction package to said heat source, said second configuration
of said compaction package having a volume that is less than the
volume of said first configuration of said compaction package.
18. The compaction package according to claim 17 wherein said heat
shrink film portion is configured in a shape selected from the
group consisting of rectangular, isosceles trapezoidal, and "T"
shaped said "T" shaped shrink film portion having a vertical part
and a horizontal part.
19. The compaction package according to claim 17 wherein said heat
shrink film portion comprises a film selected from the group
consisting of polyolefine, polyvinyl chloride (PVC), and
polyethylene terephthalate glycol (PETG).
20. The compaction package according to claim 17 wherein said
perimeter wall comprises: a front coupled to a first sidewall; a
back coupled to said first sidewall and coupled to a second
sidewall opposing said first sidewall, said second sidewall being
coupled to said front.; and a back coupled to said first sidewall
and coupled to a second sidewall opposing said first sidewall, said
second sidewall being coupled to said front; and wherein said
shrink film portion is coupled to said flexible film portion at one
or more side corner edges where said front couples to said first
sidewall, said back couples to said first sidewall and couples to
said second sidewall and where said second sidewall couples to said
front.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to packaging for granular
materials and more particularly to the use of heat shrink film
portions in packing to exclude or limit oxygen from the package and
to avoid attrition of packaged granular material during shipping
and storage.
DESCRIPTION OF RELATED ART
[0002] Vacuum packaging technology is well known in the art. For
example, in the food, detergent, coffee, and industrial material
packaging arts, semi-rigid packages are used to contain material
while a vacuum is drawn on the packaging. While under vacuum, the
package is sealed. In this process, air, containing oxygen, is
removed from the container to maintain freshness in the product
during transport and storage before sale of the product to a
consumer. Further, the vacuum package tends to compact granular
materials contained in the package as a vacuum is drawn thus
providing more efficient packages for these types of material.
Attrition of granular material is also limited because individual
grains of material are constrained from movement relative to other
particles in the vacuum package.
[0003] A description of vacuum packaging of ground coffee is
contained in U.S. Pat. No. 4,957,753. U.S. Pat. No. 5,598,684
discloses a vacuum package, and a method and apparatus for making
vacuum packages filled with granular material. As noted, when a
vacuum type package is used to package granular material such as
ground coffee, attrition of the granular material is typically less
than material attrition in loose-pack type packages since the
granular material is limited in movement when compacted by a vacuum
package. However, commercial vacuum packaging generally requires
expensive vacuum generation equipment and complicates the overall
design of a packaging line. Further, conventional vacuum packaging
is venerable to punctures and leaks in the package that degrades
package performance.
[0004] Shrink packaging is a more recent packaging development that
avoids some of the shortcomings of vacuum packaging. Further, for
granular material shrink packaging offers certain advantages over
vacuum packing while still providing much of its oxygen excluding,
packaging efficiency, and attrition minimizing benefits. Still
further, shrink packaging has a faster packing rate (units/minute)
than vacuum packaging. For example, U.S. Pat. No. 6,945,015
discloses a shrink wrap transportable container and methods. The
invention provides a package diameter reducing system for reducing
the diameter of a flexible cylindrical container as the container
is filled. The system relies on a package that comprises material
that shrinks when heated to a certain critical heat shrink
temperature. The system includes a heat generating shrinking device
to shrink the container at the fill level as the container is
filled with a plurality of particles. The shrinking device can
include a heater to supply direct heat at the fill level. Shrinking
of the container at the fill level tends to evacuate
oxygen-containing air as the container fills and limits granular
product attrition through supporting engagement between granular
particles.
[0005] In prior art shrink packaging, a package was first formed
from heat shrink film portion such as polyolefin, polyvinyl
chloride (PVC), or polyethylene terephthalate glycol (PETG) shrink
film. As is well known by those of ordinary skill in the art, such
heat shrink film portions contract when exposed to a heat source
that raises the package temperature above a certain critical
temperature. A process of heat treating a biaxially oriented film
of polyolefin, thermoplastic, crystallizable polymeric material and
the like provides the heat activated shrink properties to the
shrink film. Depending on how the film is processed, shrinkage
rates may be independently controlled in both a transverse
direction across the film and in a longitudinal direction along the
film perpendicular to the film transverse direction.
[0006] A distinguishing characteristic of biaxially oriented
packaging film is its capacity, upon exposure to some level of
heat, to shrink or, if restrained, to create shrink tension within
the film. Typically, heat shrink film portions also have excellent
heat seal properties at low temperatures, sliding properties over a
wide range of temperatures and releasing properties from a hot
plate, all of which are desirable for packaging articles by the use
of automatic packaging machines.
[0007] In a typical method of heat shrink packaging, shrink film is
first formed into a tube by, for example, extrusion. The tube may
then be made into individual bags into which the item to be
packaged is placed, then sealed at one or both ends, either
thermally or with some sort of closure device. Shrink film, for
instance, is used for packaging food in this way. However, a major
thrust in bag type packaging is the formation of bags from a
continuous roll of film sheet rather than from pre-extruded tube,
where the items to be packaged may often be disposed in a tray.
Here, bags are formed continuously around the item or trayed items.
This is achieved by first forming the sheet into a continuous tube,
around continuously supplied items or trays by continuously sealing
the film edges together, longitudinally, below the item or tray,
and then sealing (or cutting then sealing) the tube in the
direction transverse to the direction of the moving tube and trays,
into individual bags. The tube is generally formed horizontally,
around the continuously fed items or trays. The items or trays in
the tube are moved along, with the tube, by a horizontal conveyor.
The direction in which the film, the tube formed from the film, and
the item or trays travel is commonly referred to as the "machine"
direction or longitudinal direction. The direction of the sealing
and cutting of the formed tube between each tray is commonly
referred to as the "cross" transverse direction.
[0008] The general mode of continuous operation, film
sheet-to-tube-to-bag, is common to many continuous packaging
machines, using different type of film. However, not only are there
differences in how the tube is formed, but there are major
differences in the type of seal, and in how the longitudinal and
transverse seals are made. There is then the question of if and how
the formed bag is then operated on to finish the packaging
operation. Since the method of sealing and the type of seal varies,
the nature of the resulting bag will vary. Typically, it will
depend on the type of film--hard, stretch or shrink. Three common
forms of seal are the `fin`-seal where the film sheet is pressed
together to form a fin, the `bead`-seal, where film is pressed
together, melts and forms a bead or beads (sometimes referred to as
welding), and an "overwrap" seal, where cut ends are pressed around
the item or trayed items and sealed. Fin-seals may also be
subsequently overwrapped.
[0009] A continuous packaging machine of the above described
general mode of operation, i.e. sheet-to-tube-to-bag, is described
in U.S. Pat. No. 5,125,216. In this particular case, the disclosure
appears to describe formation of a loose bag from hard film, and
the item is not necessarily in a tray. It uses fin type seals both
in the longitudinal and transverse direction. Fin-seals are
generally not particularly tight seals, and are generally not
suitable for packaging moisture containing items.
[0010] A major disadvantage of containing products and, more
particularly, granular material products in a package made up of
shrink film is the cost of heat shrink film portion material itself
when compared to the cost of conventional flexible packaging
film.
SUMMARY OF THE INVENTION
[0011] The present invention provides an inexpensive,
cost-effective compaction package adapted for use with granular
materials. The compaction package of the present invention uses
considerably less expensive heat shrink film material than does a
prior art package made completely of heat shrink film.
[0012] The package is a composite package that includes a flexible
film portion and a heat shrink film portion coupled to the flexible
film portion. An opening at the top of the compaction package
provides a means to fill a volume defined by the package with a
granular material prior to exposure of the package to a heat source
capable of activating the heat shrink film portion of the
compaction package. When the compaction package is exposed to a
heat source sufficient to activate the heat shrink film portion of
the compaction package, the heat shrink film portion of the
compaction package shrinks and reduces the volume of the compaction
package thereby compacting the granular material contained within
the compaction package.
[0013] The heat shrink film portion of the package is coupled to
the flexible film portion of the compaction package at one or more
considered positions of the compaction package. When exposed to a
heat source of sufficient intensity to activate the heat shrink
film portion, the compaction package according to the present
invention provides shrinkage in the volume of the interior space of
the package that substantially achieves the volume shrinkage
provided by a prior art compaction package made up entirely of heat
shrink film portion material. Since only a portion of the
compaction package is formed from expensive heat shrink film the
compaction package of the present invention is less costly than
prior art shrink film packages formed entirely from shrink
film.
[0014] Compaction of contained product protects the product from
degrading during transport/distribution due to attrition and
abrasion. This is especially true for brittle granular products
that undergo shock and vibration such as, for example, cat litter.
The compaction packaging of the present invention is adaptable to
many conventional flexible packaging lines, because it requires
only the addition of a heating tunnel.
[0015] In one embodiment, the flexible film portion of the
compaction package defines an open top container having a bottom
and a perimeter wall coupled to the peripheral edge of the bottom.
Four upright walls coupled at their respective side edges form the
perimeter wall. The compaction may be integrally formed by means
well known to those of ordinary skill in the art by, for example,
blow film forming, or other well-known means.
[0016] In this embodiment, a strip of heat shrink film portion is
coupled to and overlies part of one or more of the upright walls of
flexible film portion of the compaction package. The heat shrink
film portion is biased to shrink in only the transverse direction
across the film when exposed to a heat source of sufficient
intensity. In another embodiment, the heat shrink film portion is
bias to shrink the longitudinal direction. In yet another
embodiment, the heat shrink film portion is bias to shrink in both
the transverse and the longitudinal directions.
[0017] In another particularly advantageous embodiment, a strip of
heat shrink film is coupled to and overlies part of the flexible
film portion of the compaction package at each of the side corner
edges of the package where the upright walls intersect. The heat
shrink film portion may be biased to shrink in only the transverse
direction across the film, only in the longitudinal direction along
the length of the compaction package, or in both the transverse and
longitudinal directions when exposed to a heat source of sufficient
intensity to raise the compaction package above a critical shrink
temperature.
[0018] Thus, provided is a compaction package in accordance with
the principle of the present that avoids the limitations of and
provides advantages over prior art vacuum compaction packages.
Further, provided is a composite shrink-film compaction package
that provides cost advantages over prior art shrink film packages
and that is particularly adapted to contain granular material such
as cat liter, powder detergents, foods such as rice, beans, coffee
and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Reference will now be made to the drawings wherein like
numerals refer to like parts throughout. When considered in
conjunction with the subsequent detailed description, a complete
understanding of the present invention may be obtained by reference
to the accompanying drawings, in which:
[0020] FIG. 1A is a perspective view of an embodiment of a filled
compaction package in accordance with the principles of the present
invention, prior to compaction and having an open top and
rectangular bottom;
[0021] FIG. 1B is a perspective view of the compaction package of
FIG. 1A after sealing of the open top and compaction by application
of heat;
[0022] FIG. 1C is a top sectional view of the compaction package of
FIG. 1A taken along line 1C'-1C' of FIG. 1A
[0023] FIG. 1D is a close up view of the area encircled by dotted
line in FIG. 1C showing a bonding bead coupling a sidewall heat
shrink film portion and a sidewall flexible portion of compaction
package 100;
[0024] FIG. 1E is a top sectional view as showing the compaction
package of FIG. 1B taken along the line 1E'-1E' after compaction
through application of heat;
[0025] FIG. 2A is a top sectional view of similar to the view of
FIG. 1C showing another embodiment of a compaction package in
accordance with the principles of the present invention before
compaction;
[0026] FIG. 2B is a close up view of the area encircled by dotted
line in FIG. 2A showing a bonding bead coupling sidewall heat
shrink film portion and a sidewall flexible portion;
[0027] FIG. 3 is a perspective view of another embodiment of a
filled compaction package in accordance with the principles of the
present invention, prior to compaction and having an open top and a
rectangular bottom;
[0028] FIG. 4 is a perspective view of another embodiment of a
filled compaction package in accordance with the principles of the
present invention, prior to compaction and having an open top and a
rectangular bottom;
[0029] FIG. 5A is a perspective view of another embodiment of a
filled compaction package in accordance with the principles of the
present invention, prior to compaction and having an open top and a
rectangular bottom;
[0030] FIG. 5B is a perspective view of the compaction package of
FIG. 5A after sealing of the open top and compaction by application
of heat; and
[0031] FIG. 6 is a perspective view of another embodiment of a
filled compaction package in accordance with the principles of the
present invention having a circular bottom and after compaction by
application of heat.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Reference will now be made to the drawings wherein like
numerals refer to like parts throughout. As used herein, positional
terms, such as "bottom", "left" and the like, and directional
terms, such as "upward", "inward" and the like, are employed for
ease of description in conjunction with the drawings. None of these
terms is meant to indicate that the described part or assembly must
have a specific orientation except when specifically set forth. It
is also to be understood that the specific elements and processes
illustrated in the attached drawings, and described in the
following specification are simply exemplary embodiments of the
inventive concepts defined in the appended claims. Hence, physical
characteristics relating to the embodiments disclosed herein are
not to be considered as limiting, unless the claims expressly state
otherwise.
[0033] In one embodiment, a compaction package in accordance with
the principles of the present invention includes a flexible plastic
film portion and a heat shrink film portion coupled to the flexible
film portion. The flexible film portion and the heat shrink film
portion of the compaction package together define a flexible
container adapted to contain a granular material such as
cat-litter. The compaction package includes a bottom, a sidewall
coupled to the peripheral edge of the bottom, and an opening at the
top of the package.
[0034] The compaction package is typically filled with a granular
material, such as cat litter, through the opening. The compaction
package has a first configuration prior to exposure to a heat
source capable of raising the temperature of the compaction package
above a certain critical temperature. The compaction package has a
second configuration after exposure of the filled compaction
package to the heat source. The second configuration of the
compaction package after exposure to a heat source has a volume
that is less than the volume of the first configuration of the
compaction package prior to exposure to the heat source.
[0035] More particularly, FIG. 1A is a perspective view of an
embodiment of a filled compaction package 100 in accordance with
the principles of the present invention, prior to compaction and
having an open top 102 and rectangular bottom 103. FIG. 1B is a
perspective view of the compaction package of FIG. 1A after sealing
of the open top and compaction by application of heat. FIG. 1C is a
top sectional view of the compaction package of FIG. 1A taken along
line 1C'-1C' of FIG. 1A.
[0036] Referring to FIGS. 1A, 1B, and 1C together, before
application of heat, compaction package 100 is generally configured
as a rectangular polyhedron surface defining an open-ended hollow
container and having a rectangularly shaped bottom 103 and
rectangular upright walls coupled to and projecting from the
peripheral side edges of bottom 103. In one embodiment, compaction
package 100 is formed from plastic sheet materials.
[0037] The rectangular upright walls are coupled to the peripheral
side edges of bottom 103 include a front 105 coupled to both a left
sidewall 106L and a right sidewall 106R (FIG. 1C), and a back 108
(FIG. 1C) opposite front 105 also coupled to both left and right
sidewalls 106L and 106R. Bottom 103 and the various peripheral
walls define an opening 109 (FIG. 1A) and an interior space 110
adapted to contain a material. A shown in FIG. 1A, a granular
material 112 has been placed in interior space 110 through opening
109.
[0038] In one embodiment, left sidewall 106L includes a left
sidewall flexible portion 114L formed of, for example, conventional
flexible polymer sheet material such as polyethylene film commonly
used in flexible packaging. Coupled to and overlying a part of left
sidewall flexible portion 114L of left sidewall 106L, is a left
sidewall heat shrink film portion 116L. Similarly, right sidewall
106R (FIG. 1C) includes a right sidewall flexible portion 114R
(FIG. 1C) of polyethylene film. Coupled to and overlying a part of
right sidewall flexible portion 114R of right sidewall 106R, is a
right sidewall heat shrink film portion 116R (FIG. 1C). In the
embodiment shown in FIGS. 1A and 1C, left and right sidewall heat
shrink film portions 116L and 116R are configured as rectangles.
Since only a portion of the left and right sidewalls 106L and 106R
comprises costly heat shrink film portion, the overall cost of
compaction package 100 is less than the cost of a prior art
compaction package that comprised expensive heat shrink film
portion for the entire package.
[0039] In one embodiment, compaction package 100 includes left and
right sidewall heat shrink film portions 116L and 116R that are
coupled to and overlie a part of left and right sidewall flexible
portion 114L and 114R by means of adhesive material. In other
embodiments, left and right sidewall heat shrink film portions 116L
and 116R are coupled respectively to left and right sidewall
flexible portion 114L and 114R by other well-known means such as,
for example, heat welding, "fin"-sealing or "bead"-sealing, where
the overlapping parts of the film sheets are vigorously pressed
together and melted due to frictional heat to form a bonding bead
or beads when cooled.
[0040] FIG. 1D is a close up view of the area encircled by dotted
line in FIG. 1C showing a bonding bead 118 coupling right sidewall
heat shrink film portion 216R with right sidewall flexible portion
114R of compaction package 100. Referring now to FIGS. 1C and 1D
together, in one embodiment left and right sidewall heat shrink
film portions 116L and 116R are coupled to left and right sidewall
flexible portions 114L and 114R by a bonding bead 118. Further, as
best seen in FIG. 1D, left and right sidewall heat shrink film
portions 116L and 116R respectively, overlie left and right
sidewall flexible portions 114L and 114R to form a double film
layer at those overlain parts of compaction package 100.
[0041] Returning attention to compaction package 100, FIG. 1B is a
perspective view of compaction package 100 of FIG. 1A after
compaction by application of heat. FIG. 1E is a top sectional view
of compaction package 100 of FIG. 1B taken along line 1E'-1E' of
FIG. 1B. Referring to FIGS. 1A, 1B and 1E together, in using
compaction package 100 to secure and compact granular material,
compaction package 100 is fabricated as described and filled with
granular material 112 through opening 109 (FIG. 1A) to fill
interior space 110 of compaction package 100 prior to application
of heat. Next, filled compaction package 100 is heated to raise the
temperature of left and right sidewall heat shrink film portions
116L and 116R above their critical heat shrink temperature. As
noted, when heated above a certain critical temperature, PETG and
other shrink films exhibit shrinkage biased in at least one
direction, typically longitudinally along a length or transversely
across a width of a shrink film. A heat tunnel (not shown) may
provide sufficient heat to raise the temperature of left and right
sidewall heat shrink film portions 116L and 116R above the critical
heat shrink temperature. Other means of supplying at least
localized heat sufficient to cause shrinkage of left and right
sidewall heat shrink film portions 116L and 116R are possible.
After application of heat and as shown in the FIGS. 1B and 1E, left
and right sidewall heat shrink film portions 116L and 116R have
shrunk transversely across their respective widths, as indicated by
heat shrink arrows 120, thereby pulling front 105 and back 108
closer together and reducing the volume of interior space 110 of
compaction package 100. Left sidewall flexible portion 114L and
right sidewall flexible portion 114R form pleats or folds 122 as
shown to accommodate the shrinkage of left and right sidewall heat
shrink film portions 116L and 116R to which they are respectively
coupled.
[0042] When heat is first applied to compaction package 100, left
and right sidewall heat shrink film portions 116L and 116R are
initially unconstrained and thus shrink to reduce the volume of
interior space 110. As the volume of interior space 110 decreases,
compaction package 100 may be constrained from further shrinkage by
contact with and compression of granular material 112 around which
compaction package 100 shrinks. Said another way, the interstial
spacing between individual granules of granular material 112
decreases. Upon further application of heat, tension in the films
comprising compaction package 100 increases in response to
compression of granular material 112. Relative movement between
individual granules of granular material 112 is constrained thereby
reducing attrition of granular material 112 during handling,
shipping, and storage.
[0043] FIG. 2A is a top sectional view similar to the view of FIG.
1C showing another embodiment of a compaction package 200 in
accordance with the principles of the present invention. FIG. 2B is
a close up view of the area encircled by dotted line in FIG. 2A
showing a bonding bead 218 coupling a right sidewall heat shrink
film portion 216R with a right sidewall flexible portion 214R of
compaction package 200. Referring to FIGS. 2A and 2B together, in
this embodiment, left and right sidewall heat shrink film portions
216L and 216R are coupled respectively to left and right sidewall
flexible portions 214L and 214R but do not completely overlie left
and right sidewall flexible portions 214L and 214R. In this
embodiment, sidewall flexible portions are discontinuous, having a
respective sidewall heat shrink film portion interposed between and
coupled to edges of the discontinuous parts of the sidewall
flexible portions. Left and right sidewall flexible portions 214L
and 214R define gaps 215L and 215R, respectively, and do not
completely underlie respectively left and right sidewall heat
shrink film portions 216L and 216R to form a double film layer of
the compaction package 100 of FIG. 1C. Since the left and right
sidewall flexible portions are discontinuous at the sidewall heat
shrink film portions, less sidewall flexible material is used
thereby reducing the material cost for compaction package 200 of
FIG. 2A when compared to the material cost for compaction package
100 of FIG. 1C.
[0044] In compaction package 200, upon application of heat
sufficient to shrink interposed left and right sidewall heat shrink
film portions 216L and 216R, the edges of discontinuous left
sidewall flexible portion 214L and right sidewall flexible portion
214R coupled respectively to left and right sidewall heat shrink
film portions 216L and 216R are drawn closer together. Since, left
sidewall flexible portion 214L and right sidewall flexible portion
214R are coupled to edges of the discontinuous parts of their
respective sidewall flexible portions, little or no folding or
pleating of left and right sidewall flexible portions 214L and 214R
occurs as in compaction package 20 of FIG. 2A. This feature of
compaction package 200 provides a package with a smoother
appearance without the pleats or folds of compaction package 100 of
FIG. 1B. Other embodiments of a compaction package in accordance
with the principles of the present invention described below may
utilized the discontinuous flexible portion techniques of
compaction package 200 as well as the continuous flexible portion
techniques of compaction package 100.
[0045] FIG. 3 is a perspective view of another embodiment of a
filled compaction package 300 in accordance with the principles of
the present invention, prior to compaction and having an open top
302 and rectangular bottom 303. Compaction package 300 is generally
configured as a rectangular polyhedron surface defining an
open-ended hollow container made from sheet material, having bottom
303 and rectangular sidewalls coupled to the peripheral side edges
of bottom 303. Compaction package 300 includes a front 305 coupled
to both a left sidewall 306L and a right sidewall 306R (not seen in
FIG. 3), and a back 308 (not seen in FIG. 3) opposite front 305
also coupled to both left and right sidewalls 306L and 306R to
define an opening 309 and an interior space 310 adapted to contain
a material. A shown in FIG. 3, a granular material 312 has been
placed in interior space 310 through opening 309.
[0046] In one embodiment of the compaction package 300 of FIG. 3,
left sidewall 306L includes a left sidewall flexible portion 314L
formed of, for example, conventional flexible polymer sheet
material such as polyethylene film commonly used in flexible
packaging. Coupled to left sidewall flexible portion 314L of left
sidewall 306L, is a left sidewall heat shrink film portion 316L.
Similarly, right sidewall 306R (not seen in FIG. 3) includes a
right sidewall flexible portion 314R (not seen in FIG. 3) of
polyethylene film. Coupled to right sidewall flexible portion 314R
of right sidewall 306R, is a right sidewall heat shrink film
portion 316R (not seen in FIG. 3). Sidewall heat shrink film
portions of compaction package 300 may be coupled to sidewall heat
shrink film portions by various means.
[0047] As seen in FIG. 3, left and right sidewall heat shrink film
portion 316L is configured as isosceles trapezoids having a wide
parallel end 320W and a narrow parallel end 320N. (In FIG. 3 only
right sidewall 306R is shown; left sidewall 306L is similarly
configured). Each of the left and right sidewall heat shrink film
portions 316L and 316R is coupled to its respective left and right
sidewall flexible portion 314L and 314R such that wide parallel
side 320W of the isosceles trapezoid-shaped sidewall heat shrink
film portion is nearest opening 309 at top 302 of compaction
package 300.
[0048] For transversely biased heat shrink film portion, upon
application of heat sufficient to cause shrinkage of left and right
sidewall heat shrink film portions 316L and 316R, the top 302 of
the sidewalls 306L and 306R of compaction package 300 shrink a
greater amount at opening 309 than at bottom 303 of compaction
package 300 owing to the trapezoidal bottom to top expanding taper
of left and right sidewall heat shrink film portions 316L and 316R.
Since the width of the wide parallel end 320W of the sidewall heat
portions shrinks a greater distance across its width than the does
the narrow parallel end 320N bottom of the heat shrink film
portions, the sidewall shrinkage of compaction package 300 is
greatest at the top of compaction package 300 nearest opening
309.
[0049] FIG. 4 is a perspective view of another embodiment of a
filled compaction package 400 in accordance with the principles of
the present invention, prior to compaction and having a
rectangularly shaped bottom 403. As shown in FIG. 4, a left and
right sidewall heat shrink film portion 416L and 416R (not seen in
FIG. 4) are configured as "T" shaped film structures having a
vertical part 420V and a horizontal part 420H. (In FIG. 4 only
right sidewall 406R is shown; left sidewall 406L is similarly
configured). As in other embodiments described above, each of the
left and right sidewall heat shrink film portions 416L and 416R is
coupled to its respective left and right sidewall flexible portion
414L and 414R. In this embodiment, respective horizontal parts 420H
of sidewall heat shrink film portions 416L and 416R are nearest an
opening 409 at the top of compaction package 400.
[0050] In compaction package 400, the "T" shaped left and right
sidewall heat shrink film portions 416L and 416R are integrally
formed from a sheet of heat shrink material prior to coupling
respective sidewall heat shrink film portions. The heat shrink film
portion forming sidewall heat shrink film portions 416L and 416R is
biased to shrink only horizontally in a transverse direction across
the film when exposed to a heat source of sufficient intensity. The
heat shrink film portion is position and coupled to the flexible
film portion of the compaction package such that the shrinkage bias
of the shrink film is in the transverse, side-to-side direction of
the compaction package. When so configured and formed, compaction
package 400 will perform similarly to compaction package 300 of
FIG. 3. The compaction package 400 shrinks a greater amount at top
402 than at bottom 403.
[0051] FIG. 5A is a perspective view of another embodiment of a
filled compaction package in accordance with the principles of the
present invention, prior to compaction and having an open top and a
rectangular bottom. FIG. 5B is a perspective view of the compaction
package of FIG. 5A after sealing of the open top and compaction by
application of heat. Referring to FIGS. 5A and 5B together, in this
embodiment, compaction package 500 is again generally configured as
a rectangular polyhedron surface defining an open-ended hollow
container made from sheet material, having a rectangular bottom 503
and rectangular upright walls coupled to the peripheral side edges
of bottom 503. Compaction package 500 includes a front 505 coupled
to both a left sidewall 506L and a right sidewall 506R (not seen in
FIG. 5A or 5B), and a back 508 (not shown) opposite front 505 also
coupled to both left and right sidewalls 506L and 506R to define an
opening 509 and an interior space 510 adapted to contain a material
512.
[0052] In this embodiment, strips of transversely biased heat
shrink film portion 524 are coupled to and overlie part of a
flexible film portion 514 of compaction package 500 at each of the
side corner edges of compaction package 500 where its peripheral
upright walls intersect. In this embodiment all four upright walls,
i.e. the two sidewalls, the front and the back of compaction
package will shrink transversely upon application of sufficient
heat. As shown in FIG. 5B, pleats 522 form in each of the four
upright peripheral walls of compaction package 500 to accommodate
the shrinkage of all of the upright walls.
[0053] It would be apparent to one of ordinary skill in the art
that many variations in accordance with the principles of the
present invention on the specific configurations and locations of
the flexible and heat shrink film portions described herein are
possible. Illustratively, front 105 and back 108 of compaction
package 100 of FIGS 1A-1C may also include heat shrink film
portions similar to the sidewall heat shrink film portions shown.
Accordingly, shrinkage of a compaction package having both lateral
sidewall and front/back sidewall heat shrink film portions occurs
in both the front-to-back direction and in the side-to-side
direction upon application of heat sufficient to cause shrinkage of
the heat shrink film portions of the compaction package.
[0054] Further, by way of illustration, in another embodiment, the
bias of the heat shrink film portions may be longitudinal instead
of transverse as described, thus causing shrinkage of the
compaction package in a top-to-bottom direction upon application of
heat sufficient to cause shrinkage of the heat shrink film
portions. Alternatively, the heat shrink material making up the
various heat shrink film portions described may shrink in both the
transverse and longitudinal direction, thus causing shrinkage of
the compaction package of the present invention to occur in any or
all of the front-to-back, side-to-side, and top-to-bottom
directions upon application of sufficient heat to the package. In
yet another embodiment, and as described below with reference to
FIG. 6, a compaction package in accordance with the principles of
the present invention may be generally configured as a cylindrical
surface having a circular bottom.
[0055] FIG. 6 is a perspective view of another embodiment of a
filled compaction package 600 in accordance with the principles of
the present invention having a circular bottom 603 and after
compaction by application of heat. In compaction package 600, a
continuous upright wall 630 is coupled to the perimeter of circular
bottom 603 forming a cylindrical shaped container defining an
interior space 610 adapted to contain a granular material 612.
Compaction package 600 further includes one or more perforation
lines 628 that circumscribe compaction package 600. Perforation
lines 628 form weakened portions of compaction package 600 and are
designed to yield upon application of force on compaction package
600. By this means, a portion of the granular material 612 may be
separated from the remainder of compaction package 600 without
disrupting the compaction of the remaining granular material in the
remainder of compaction package 600.
[0056] While the invention is described herein in connection with
certain exemplar embodiments, there is no intent to limit the
present invention to those embodiments. On the contrary, it is
recognized that various changes and modifications to the described
embodiments will be apparent to those skilled in the art upon
reading the foregoing description, and that such changes and
modifications may be made without departing from the spirit and
scope of the present invention. Skilled artisans may employ such
variations as appropriate, and the invention may be practiced
otherwise than as specifically described herein. Accordingly, the
intent is to cover all alternatives, modifications, and equivalents
included within the spirit and scope of the invention.
* * * * *