US20090238498A1

US20090238498A1 - Compaction Package

Info

Publication number: US20090238498A1
Application number: US12/050,426
Authority: US
Inventors: Kevin Lin
Original assignee: Individual
Current assignee: Clorox Co
Priority date: 2008-03-18
Filing date: 2008-03-18
Publication date: 2009-09-24

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.

Description

FIELD OF THE INVENTION

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

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.
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.
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.
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.
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.
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.
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.
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.
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

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.
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.
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.
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.
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.
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.
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.
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

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:

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;

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

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;

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;

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;

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;

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;

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;

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; and

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

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.

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;

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.