U.S. patent application number 12/389172 was filed with the patent office on 2009-09-03 for releasable locking mechanism for packaging articles.
Invention is credited to Elie Helou, JR..
Application Number | 20090218347 12/389172 |
Document ID | / |
Family ID | 40986183 |
Filed Date | 2009-09-03 |
United States Patent
Application |
20090218347 |
Kind Code |
A1 |
Helou, JR.; Elie |
September 3, 2009 |
RELEASABLE LOCKING MECHANISM FOR PACKAGING ARTICLES
Abstract
One embodiment of the present invention provides a novel
packaging article, which includes a cover and a base having
non-edge localized connecting structures, such as, a protrusion and
a receptacle cavity. The cover and the base may have different
thermal expansion coefficients such that, when subject to heating
(e.g., microwave heating) or cooling (e.g., refrigerate storage),
the cover and the base do not expand or shrink to the same degree.
Furthermore, the cover and/or the base may comprise a biodegradable
or edible material, such as, without limitation, starch.
Inventors: |
Helou, JR.; Elie; (Santa
Barbara, CA) |
Correspondence
Address: |
PERKINS COIE LLP
POST OFFICE BOX 1208
SEATTLE
WA
98111-1208
US
|
Family ID: |
40986183 |
Appl. No.: |
12/389172 |
Filed: |
February 19, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61029901 |
Feb 19, 2008 |
|
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|
Current U.S.
Class: |
220/309.1 |
Current CPC
Class: |
Y02W 90/13 20150501;
B65D 2543/00703 20130101; Y02W 90/11 20150501; B65D 43/0202
20130101; B65D 2543/00805 20130101; Y02A 40/961 20180101; B65D
65/463 20130101; Y02A 40/90 20180101; B65D 65/466 20130101; Y02W
90/10 20150501; B65D 81/3453 20130101; B65D 2543/00731 20130101;
B65D 2543/00666 20130101 |
Class at
Publication: |
220/309.1 |
International
Class: |
B65D 43/00 20060101
B65D043/00 |
Claims
1. A packaging article comprising: a cover comprising a first
structure; and a base comprising a second structure, wherein
connecting the first structure and the second structure links the
cover and the base to form an assembled packaging article, wherein
the first structure is not localized on an edge of the cover, and
wherein the second structure is not localized on an edge of the
base.
2. The packing article of claim 1, wherein the first structure is a
protrusion and the second structure is a receptacle cavity.
3. The packing article of claim 1, wherein the first structure is a
receptacle cavity and the second structure is a protrusion.
4. The packing article of claim 1, wherein at least one of the
first structure and the second structure comprises a locking
structure.
5. The packing article of claim 1, wherein the cover has a
different thermal expansion coefficient from that of the base.
6. The packing article of claim 5, wherein the cover has a smaller
thermal expansion coefficient than that of the base.
7. The packing article of claim 1, wherein the cover expands or
contracts differently from the base with a change of moisture
content.
8. The packing article of claim 1, wherein at least one of the
cover and the base comprises a biodegradable or edible
material.
9. The packing article of claim 7, wherein the biodegradable or
edible material comprises starch.
10. A packaging article comprising: a cover comprising a first
connecting structure in an inner section of the cover; and a base
comprising a second connecting structure in an inner section of the
base, wherein connecting the first connecting structure and the
second connecting structure links the cover and the base.
11. The packaging article of claim 10, wherein the first connecting
structure and the second connecting structure together form a snap
fit for releasably linking the cover and the base.
12. The packaging article of claim 11, wherein the snap fit is an
annular snap fit.
13. The packaging article of claim 11, wherein the snap fit is an
cantilever snap fit.
14. The packaging article of claim 10, wherein the cover and the
base comprise different materials.
15. The packaging article of claim 10, wherein the cover and the
base comprise the same material.
16. The packaging article of claim 10, wherein the cover and base
expand or contract differently in response to environmental
conditions.
17. The packaging article of claim 10, wherein the cover and base
expand or contract the same in response to environmental
conditions.
18. The packaging article of claim 10, wherein at least one of the
cover and base comprises a starch-based material.
19. The packaging article of claim 18, wherein the first connecting
structure and the second connecting structure together form a snap
fit for releasably linking the cover and the base.
20. The packaging article of claim 19, wherein the snap fit is an
annular snap fit.
21. The packaging article of claim 19, wherein the snap fit is an
cantilever snap fit.
22. The packaging article of claim 10, wherein both the cover and
base comprise a starch-based material.
23. The packaging article of claim 22, wherein the first connecting
structure and the second connecting structure together form a snap
fit for releasably linking the cover and the base.
24. The packaging article of claim 23, wherein the snap fit is an
annular snap fit.
25. The packaging article of claim 23, wherein the snap fit is an
cantilever snap fit.
26. A packaging article comprising: a cover comprising a first
connecting structure in an inner section of the cover; and a base
comprising a second connecting structure in an inner section of the
base, wherein connecting the first connecting structure and the
second connecting structure links the cover and the base, and
wherein at least one of the cover and the base comprises a
starch-based material.
27. The packaging article of claim 26, wherein both the cover and
base comprise a starch-based material.
28. The packaging article of claim 27, wherein the first connecting
structure and the second connecting structure together form a snap
fit for releasably linking the cover and the base.
29. The packaging article of claim 28, wherein the snap fit is an
annular snap fit.
30. The packaging article of claim 28, wherein the snap fit is an
cantilever snap fit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/029,901, filed Feb. 19, 2008, which is
incorporated herein by reference.
FIELD
[0002] The invention generally relates to a novel packaging
article.
BACKGROUND
[0003] Various types of rigid and semi-rigid containers are used to
package food items and non-food items, such as medical supplies and
devices. In general, these containers provide at least one shaped
cavity defined by a base and a cover within which a product is
supported and may be protected against environmental contamination
when the container is sealed.
[0004] Such containers are often subject to treatments under
various temperatures, such as, heating in a microwave or storing in
a refrigerator. It is not uncommon for a food container to be
subject to microwave heating immediately after it is taken out of a
refrigerator. Such treatments could mechanically damage the
structure of the container and affect its functionality (e.g., the
function of providing proper sealing to the food in the container).
For example, when the cover and the base of the container have
different thermal expansion coefficients, when heated, the cover
and the base expend or grow at different rates. Thus, the expansion
of the one with larger thermal expansion coefficient may cause
mechanical stress to the one with smaller thermal expansion
coefficient.
[0005] In addition, under various circumstances, end user may
prefer clear, transparent, or semi-transparent covers for
containers, such as, clear covers made from regular plastics which
do not degrade or bioplastics which do degrade. In most cases, a
change in the moisture content of the environment does not change
the size and/or the shape of these lids. However, some widely-used
packaging systems have bases, such as, container bases which
contain a high percentage of starch and pulp molded containers,
which tend to grow and shrink in size based on the moisture
content. These containers may be affected by the moisture content
or temperature variation of the environment. Thus, current
available packaging systems, which are not designed to allow or
compensate for the growth/shrinkage differences between the lids
and the bases, tend to have difficulty to provide sufficient
sealing for their content.
[0006] Therefore, there is a need in the art for novel packaging
articles where the change of temperature and/or moisture does not
substantially affect their functionality and/or structural
integrity.
SUMMARY
[0007] One embodiment of the present invention provides a packaging
article, which includes a cover comprising a first structure and a
base comprising a second structure, wherein connecting the first
structure and the second structure causes the cover and the base to
form an assembled packaging article, wherein the first structure
and the second structure are not localized on the edge of the cover
and the base, respectively. In said embodiment, the first structure
may be a protrusion and the second structure may be a receptacle
cavity. In another embodiment, the first structure may be a
receptacle cavity and the second structure may be a protrusion. In
yet another embodiment, at least one of the first structure and the
second structure may comprise a locking structure (e.g., without
limitation, a snap or snap fit structure). In some embodiments the
locking structure can be releasable.
[0008] In addition, the cover and the base may have different
thermal expansion coefficients such that, when subject to heating
(e.g., microwave heating) or cooling (e.g., refrigerated storage),
the cover and the base do not expand or shrink to the same degree.
In one embodiment, the cover may have a smaller thermal expansion
coefficient than that of the base.
[0009] Furthermore, the cover and the base may expand and/or shrink
differently with a change of the moisture content and/or a change
of moisture content in the environment.
[0010] Also provided is a packaging article having a cover and/or a
base, which may comprise a biodegradable or edible material, such
as, without limitation, starch, and/or pulp.
[0011] Other features and advantages of the present invention will
become apparent from the following detailed description. It should
be understood, however, that the detailed description and the
specific examples, while indicating the preferred embodiments of
the present invention, are given by way of illustration only, since
various changes and modifications within the spirit and scope of
the present invention will become apparent to those skilled in the
art from this detailed description.
FIGURES
[0012] FIG. 1 shows three perspective views of a representative
packaging article in accordance with embodiments of the present
invention.
[0013] FIG. 2 shows a perspective view of the base of a
representative packaging article in accordance with embodiments of
the present invention.
[0014] FIG. 3 shows the cover and the base of a representative
packaging article in accordance with embodiments of the present
invention.
[0015] FIG. 4 shows the packaging article of FIG. 3, indicating the
snap on the cover and the matching hole on the base of the
packaging article.
[0016] FIG. 5 shows the cover and the base of a representative
packaging article having two snaps and two holes, respectively, in
accordance with embodiments of the present invention.
[0017] FIG. 6 shows the base of a representative packaging article
in accordance with embodiments of the present invention.
[0018] FIG. 7 shows a representative assembled packaging article
having a cover and a base in accordance with embodiments of the
present invention.
[0019] FIG. 8 shows a cross-section view of a representative
packaging article in accordance with embodiments of the present
invention.
[0020] FIG. 9 shows the cover of a representative packaging article
in accordance with embodiments of the present invention.
[0021] FIG. 10 shows the snap on the cover of a representative
packaging article in accordance with embodiments of the present
invention.
[0022] FIG. 11 shows a representative packaging article having
double snaps and double holes in accordance with embodiments of the
present invention.
[0023] FIG. 12 shows a perspective view of a representative
packaging article in accordance with embodiments of the present
invention.
[0024] FIG. 13 shows a cross-section view of a representative
packaging article having double snaps and double holes in
accordance with embodiments of the present invention.
[0025] FIG. 14 shows the cover and the base of a representative
packaging article in accordance with embodiments of the present
invention.
[0026] FIG. 15 shows a cross-section view of the representative
packaging article of FIG. 14.
[0027] FIG. 16 shows a cross-section view of the representative
packaging article of FIG. 14.
[0028] FIG. 17 shows a perspective view of the representative
packaging article of FIG. 14.
DETAILED DESCRIPTION
[0029] In order to fully understand the manner in which the
above-recited details and other advantages and objects are
obtained, a more detailed description will be rendered by reference
to specific embodiments.
[0030] One embodiment of the present invention provides a packaging
article, which includes a cover comprising a first structure and a
base comprising a second structure, wherein connecting the first
structure and the second structure causes the cover and the base to
form an assembled packaging article, wherein the first structure
and the second structure are not localized on the edge of the cover
and the base, respectively.
[0031] FIGS. 1-17 depict a number of exemplary packaging articles
that may be formed according to the present invention. The
exemplary packaging articles have regular, symmetrical shapes and
configurations. However, it should be understood that other shapes
and configurations are contemplated by the present invention.
Examples of other shapes encompassed hereby include, but are not
limited to, polygons, circles, ovals, cylinders, prisms, spheres,
polyhedrons, ellipsoids, and any other shape that may be formed
into a three-dimensional package, e.g., for receiving a food item
therein. The shape of the package may be determined by the shape of
the product intended for use therewith, and it should be understood
that different packages are contemplated for different
products.
[0032] According to one embodiment of the present invention as
shown in FIG. 1, the packaging article comprises a cover 10 and a
base 20. The cover 10 has a first structure 30, a snap protrusion,
which further comprises a locking structure 50. The base 20 has a
second structure 40, a receptacle cavity, for receiving the snap
protrusion. Both the first structure 10 and the second structure 20
are located in the inner section of the cover and the base,
respectively.
[0033] The term "located in the inner section" or "in the inner
section" as used herein refers to localizing a structure to a
position on the cover or the base other than the edge thereof. In
one embodiment, the first structure 10 and the second structure 20
are both localized in the center of the cover and the base,
respectively. In another embodiment, first structure 10 and the
second structure 20 may be located in a non-center, inner section
of the cover or the base of the packaging article of the present
invention.
[0034] In other embodiments of the present invention, the first
structure may be a protrusion and the second structure may be a
receptacle cavity. In other embodiments, the first structure may be
a receptacle cavity and the second structure may be a protrusion.
In yet additional embodiments, both the first and the second
structures may be protrusions (e.g., protrusions with interactive
locking features).
[0035] When functionally connected, the first structure and the
second structure hold the cover and the base together to form an
assembled packaging article and prevent the separation of the cover
and the base during ordinary handling or processing of the
packaging article. To secure the mechanical connection, in one
embodiment, at least one of the first structure and the second
structure may comprise a locking structure (e.g., without
limitation, a snap or snap fit). Locking or interlocking structures
suitable for the purposes of the present invention may include, but
is not limited to, annular, cantilever, and torsion snap fits.
[0036] The cover and the base may be made of any materials suitable
for the purposes of the packaging article. Examples of suitable
materials include, without limitations, starch, paper, natural
fibrous materials, a homopolymer or copolymer of polyethylene (PE),
polypropylene (PP), polyester, polystyrene (PS), polyvinylchloride
(PVC), polycarbonate (PC), polyamide, nylon, ethylene/vinyl alcohol
copolymer, such as, high-density polyethylene (HDPE), cyclic olefin
copolymer (COC), polyethylene terephthalate (PET), amorphous
polyethylene terephthalate (APET), glycol-modified polyethylene
terephthalate (PETG), polylactic acid (PLA), polystyrene (PS),
high-impact polystyrene (HIPS), polyvinylchloride (PVC),
polycarbonate (PC), or mixtures thereof.
[0037] Sources of starch may include, but are not limited to, plant
sources such as tubers, roots, seeds, and/or fruits of plants, and
specific plants sources may include corn, potato, tapioca, rice, or
wheat or similar, or animal sources, namely glycogen. In some
embodiments, starch is a combination of both pregelatinized and
uncooked or native starches. In some embodiments, the
pregelatinized starch has a concentration in the range of about 0%
to about 30% by weight of total starch in the formulation, and more
preferably 3% to 20%, and most preferably 5% to 15%. Food-grade
starches (pregelatinized or uncooked) that have been modified by
cross-linking, stabilization, or addition of lipophilic functional
groups may be included to increase resistance of the products to
softening when exposed to aqueous foods. In some embodiments, the
starch can be a water-resistant starch, and these starches can be a
modified starch, an unmodified starch such high-amylose starch, or
a combination thereof. In some embodiments, the starch component
can include a high-amylose starch. For example, the starch
component can comprise natural starch, pre-gelatinized starch,
high-amylose starch, or a combination thereof. In some embodiments,
a portion of the starch component can be comprised of one or more
water-resistant starches. The water-resistant starches may either
be standard starches that have been chemically modified to be water
resistant, or high amylose starches that are water resistant in
their native, unmodified state. In these embodiments, the
water-resistant fraction of the starch component may consist of
chemically modified water-resistant starch, naturally water
resistant high amylose starch, or a combination thereof. Use of
water-resistant starches as a portion of the starch component
increases the moisture resistance of the finished products.
[0038] As used herein, the terms "polyamide" and "nylon" are used
synonymously herein and refer to a homopolymer or copolymer having
an amide linkage between monomer units which may be formed by any
method known to those skilled in the art. The amide linkage can be
represented by the general formula:
[C(O)--R--C(O)--NH--R'--NH].sub.n where R and R'=the same or
different alkyl (or aryl) group. Examples of nylon polymers
include, but are not limited to, nylon 6 (polycaprolactam), nylon
11 (polyundecanolactam), nylon 12 (polyauryllactam), nylon 4,2
(polytetramethylene ethylenediamide), nylon 4,6 (polytetramethylene
adipamide), nylon 6,6 (polyhexamethylene adipamide), nylon 6,9
(polyhexamethylene azelamide), nylon 6,10 (polyhexamethylene
sebacamide), nylon 6,12 (polyhexamethylene dodecanediamide), nylon
7,7 (polyheptamethylene pimelamide), nylon 8,8 (polyoctamethylene
suberamide), nylon 9,9 (polynonamethylene azelamide), nylon 10,9
(polydecamethylene azelamide), nylon 12,12 (polydodecamethylene
dodecanediamide), and the like. Examples of nylon copolymers
include, but are not limited to, nylon 6,6/6 copolymer
(polyhexamethylene adipamide/caprolactam copolymer), nylon 6,6/9
copolymer (polyhexamethylene adipamide/azelaiamide copolymer),
nylon 6/6,6 copolymer (polycaprolactam/hexamethylene adipamide
copolymer), nylon 6,2/6,2 copolymer (polyhexamethylene
ethylenediamide/hexamethylene ethylenediamide copolymer), nylon
6,6/6,9/6 copolymer (polyhexamethylene adipamide/hexamethylene
azelaiamide/caprolactam copolymer), as well as other nylons which
are not particularly delineated here. Exemplary of aromatic nylon
polymers include, but are not limited to, nylon 4,1, nylon 6,1,
nylon 6,6/61 copolymer, nylon 6,6/6T copolymer, nylon MXD6
(poly-m-xylylene adipamide), poly-p-xylylene adipamide, nylon 61/6T
copolymer, nylon 6T/61 copolymer, nylon MXDI, nylon 6/MXDT/I
copolymer, nylon 6T (polyhexamethylene terephthalamide), nylon 12T
(polydodecamethylene terephthalamide), nylon 66T, nylon 6-3-T
(poly(trimethyl hexamethylene terephthalamide).
[0039] As used herein, the phrase "ethylene/vinyl alcohol
copolymer" (EVOH), refers to copolymers composed of repeating units
of ethylene and vinyl alcohol. Ethylene/vinyl alcohol copolymers
can be represented by the general formula:
[(CH.sub.2--CH.sub.2).sub.m--(CH.sub.2--CH(OH))].sub.n.
Ethylene/vinyl alcohol copolymers may include saponified or
hydrolyzed ethylene/vinyl acrylate copolymers, and refers to a
vinyl alcohol copolymer having an ethylene comonomer, and prepared
by, for example, hydrolysis of vinyl acrylate copolymers or by
chemical reactions with vinyl alcohol. The degree of hydrolysis is
preferably at least 50%, and more preferably, at least 85%.
Non-limiting examples of ethylene/vinyl alcohol copolymers include
the family of EVOH sold under the trademark SOARNOL.TM. from Nippon
Gohsei, Tokyo, Japan.
[0040] As used herein, the term "polypropylene" refers to a
homopolymer or copolymer having at least one propylene monomer
linkage within the repeating backbone of the polymer. The propylene
linkage can be represented by the general formula:
[CH.sub.2--CH(CH.sub.3)].sub.n.
[0041] As used herein, the term "polyester" refers to a homopolymer
or copolymer having an ester linkage between monomer units which
may be formed, for example, by condensation polymerization
reactions between a dicarboxylic acid and a diol. The ester linkage
can be represented by the general formula:
[O--R--OC(O)--R'--C(O)].sub.n where R and R'=the same or different
alkyl (or aryl) group and may be generally formed from the
polymerization of dicarboxylic acid and diol monomers containing
both carboxylic acid and hydroxyl moieties. The dicarboxylic acid
may be linear or aliphatic, i.e., lactic acid, oxalic acid, maleic
acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
suberic acid, azelaic acid, sebacic acid, and the like; or may be
aromatic or alkyl substituted aromatic, i.e., various isomers of
phthalic acid, such as paraphthalic acid (or terephthalic acid),
isophthalic acid and naphthalic acid. Specific examples a useful
diol include, but not limited to, ethylene glycol, propylene
glycol, trimethylene glycol, 1,4-butane diol, neopentyl glycol,
cyclohexane diol and the like. Suitable polyesters may include, a
homopolymer or copolymer of alkyl-aromatic esters, such as, for
example, but not limited to, polyethylene terephthalate (PET),
amorphous polyethylene terephthalate (APET), crystalline
polyethylene terephthalate (CPET), glycol-modified polyethylene
terephthalate (PETG), and polybutylene terephthalate; copolymers of
terephthalate and isophthalate, such as, for example, but not
limited to, polyethylene terephthalate/isophthalate copolymer; and
a homopolymer or copolymer of aliphatic esters such as, for
example, polylactic acid (PLA) and polyhydroxyalkonates, such as,
for example, but not limited to, polyhydroxypropionate,
poly(3-hydroxybutyrate) (PH3B), poly(3-hydroxyvalerate) (PH3V),
poly(4-hydroxybutyrate) (PH4B), poly(4-hydroxyvalerate) (PH4V),
poly(5-hydroxyvalerate) (PH5V), poly(6-hydroxydodecanoate) (PH6D)
and blends of any of these materials.
[0042] As used herein, the term "polystyrene" refers to a
homopolymer or copolymer having at least one styrene monomer
(benzene, i.e., C.sub.6H.sub.5, having an ethylene substituent)
linkage within the repeating backbone of the polymer. The styrene
linkage can be represented by the general formula:
[CH.sub.2--CH.sub.2(C.sub.6H.sub.5)].sub.n. Polystyrene may be
formed by any method known to those skilled in the art. Suitable
polystyrenes include, for example, but are not limited to, oriented
polystyrene (OPS) film and resins, i.e., polystyrene (PS),
syndiotactic polystyrene (SPS), acrylonitrile-butadiene-styrene
(ABS), styrene-acrylonitrile (SAN), ethylene/styrene copolymers,
styrene/acrylic copolymers, styrene block copolymers (SBC), and the
like. Other non-limiting examples of polystyrene suitable for use
in the present invention include high-impact polystyrene
(HIPS).
[0043] As used herein, the term "polyethylene" refers to a
homopolymer or copolymer having at least one ethylene monomer
linkage within the repeating backbone of the polymer. The ethylene
linkage can be represented by the general formula:
[CH.sub.2--CH.sub.2].sub.n. Polyethylenes (PE) may be formed by any
method known to those skilled in the art. Suitable polyethylenes
may include, but is not limited to, high-density polyethylene
(HDPE), ultra high-density polyethylene (UHDPE), and cyclic olefin
copolymers (COC). Exemplary of commercially available cyclic olefin
copolymers suitable for use in the present invention include, but
are not limited to, the TOPAS.TM. family of resins which is
supplied by Celanese-Ticona, Summit, N.J., U.S.A.
[0044] As used herein, the term "polyvinylchloride" refers to a
homopolymer or copolymer having at least one vinyl chloride monomer
linkage, i.e., ethylene moiety having a chlorine atom substituent
on a carbon atom, within the repeating backbone of the polymer.
Polyvinylchloride (PVC) can be represented by the general formula:
[CH.sub.2--CH(Cl)].sub.n.
[0045] As used herein, the term "polycarbonate" refers to a
homopolymer or copolymer having at least one carbonate monomer
linkage within the repeating backbone of the polymer. Polycarbonate
(PC) can be represented by the general formula:
[O--R--OC(O)].sub.n.
[0046] The cover and the base may have different thermal expansion
coefficients such that, when subject to heating (e.g., microwave
heating) or cooling (e.g., refrigerated storage) or other
environmental conditions, the cover and the base do not expand or
shrink to the same degree. In one embodiment, the cover may have a
smaller thermal expansion coefficient than that of the base. Due to
the unique and advantageous configuration of the present invention,
the differences in the degree of expansion or contraction may not
substantially affect the functionality and/or structure integrity
of the cover, the base, and/or the assembled packaging article.
[0047] Furthermore, the cover and the base may expand and/or shrink
differently with a change of the moisture content and/or a change
of moisture content in the environment. For instance, such covers
may be clear, transparent, or semi-transparent covers, e.g.,
without limitations, clear covers made from regular plastics which
do not degrade or bioplastics which do degrade (e.g., PLA), where
the changes of the moisture content of the environment generally do
not cause significant changes in the size and/or the shape of these
covers; while the bases may be bases containing a high percentage
of starch and/or pulp, which tend to grow and shrink in size based
on the moisture content, which may be affected, e.g., by the
moisture content of the environment. Therefore, the packaging
article of the present invention provides better sealing to the
content, at least partially due to the fact that it allows for the
growth/shrinkage differences between the lids and the bases.
[0048] Packaging articles with enhanced moisture resistance can be
provided by coating the article with a moisture resistant coating.
Where long term storage of food products requires a sealed moisture
and oxygen barrier, conventional coated paper or plastic film
materials may be used for barrier materials, with a rigid
biodegradable insert acting to hold and protect the food items.
[0049] A formulation according to the present invention from which
the packaging items (containers, plates, trays, bowls, cones, and
cups, as well as other novel shapes) can be produced is provided,
comprising water; starch; and optionally natural fibrous materials,
proteins, natural polymeric compounds, and wax or wax
emulsions.
[0050] Proteins and natural polymeric compounds may include, but
are not limited to preparations made from casein, soy protein
isolate or concentrate, or similar such preparations. One such
preparation can be prepared in the following three steps: 1)
cooking a solution of casein or soy protein isolate in water (about
10% by weight) as per usual manufacturer's recommendations
(generally, hydrating the protein by soaking, then gradually
raising the temperature and pH of the solution to 180.degree. F.
and pH=9 to 9.5, then holding the solution at 180.degree. F. for 15
minutes); 2) cooling the preparation to room temperature; and
optionally, 3) adding a preservative and blending thoroughly. The
preferred concentration of preservative in the preparation is about
0.1% or less, depending on the shelf life required for the protein
solution, the concentration of protein required in the final
product, and the limits imposed by government regulations on the
dosages of preservative compounds in edible materials.
[0051] Other proteins may also be used in combination with the
casein or soy protein preparation or separately to improve the
water-resistant properties of the containers. For example, such
proteins may include albumen, gelatin, or the like.
[0052] Several natural fibrous materials may be used in combination
both as structural elements (at several size scales) in the baked
items and or as inexpensive organic fillers. Fiber elements are
used both to control the molding characteristics of the wet batter
and to enhance the structural stability of the finished food
service articles. Although there is a continuum of fiber lengths
and fiber aspect ratios used in the formulation, the fibrous
portion of the formulation can be in a general sense separated into
three classes (based on fiber length) that serve different
functions. Long or very long (4 to 25 mm or longer) fibers or
composite fiber elements are used to form a meshwork that helps
prevent defects from forming in the batter as it expands in the
mold. Medium-length fibers (0.5 to 5 mm) also help control the flow
characteristics of the wet batter, and serve to increase the
toughness of the finished food service articles, preventing
fracture during handling and during normal use. Short fibers
(<0.5 mm) serve mainly as a means to introduce readily
biodegradable material into the formulation, i.e., filler material
that is more water-resistant than the starch-based matrix that
contains them.
[0053] Optionally, the shorter fibers may be used in conjunction
with, or replaced by other filler materials imparting the same
advantages as the shorter fibers. For example, such filler
materials may include both organic and inorganic aggregates such as
calcium carbonate, silica, calcium sulfate, calcium sulfate
hydrate, magnesium silicate, micaceous minerals, clay minerals,
titanium dioxide, talc, etc. The concentration of aggregate and/or
short fibers may be in a range from about 0% to about 25% by dry
weight of the formulation, in a range from about 2.5% to about 20%
by total dry weight of the formulation, in a range from about 5% to
about 15% dry weight of the formulation, in a range from about 5%
to about 20% by total dry weight of the formulation, or in a range
from about 7% to about 17% dry weight of the formulation.
[0054] The organic filler material may include ground walnut
shells. Ground walnut shells results in fibrous matter comprising
short fibers. The ground walnut shells may be used alone as the
filler material or may be combined with other filler materials.
When used alone the preferred concentration is about 8% by dry
weight.
[0055] Fibers from several sources are typically included in the
formulation. Relatively high quality fibers from grass or reed
species provide the mid-length fibers that contribute most to the
structural stability and resilience if the finished articles. The
long to very long fibers or fiber composites may come from lightly
processed agricultural byproducts, e.g., stalk or husk materials
that have been chopped, ground, or milled to an appropriate size,
or they can come from traditional sources of long cellulose fiber,
e.g., cotton or cotton linters. Under appropriate processing
conditions (e.g., hammer milling), these materials can also provide
a considerable amount of the very short fiber that serves to
replace starch and add water resistance to the finished article.
Fibrous material in the form of ground nut shells (or other very
hard, lignin-rich plant materials) may also serve as organic,
relatively water resistant, biodegradable fibers that replace
conventional filler materials.
[0056] Moreover, these other sources of fiber suitable as
structural elements in starch-based food service articles are
readily available. Some of these are from fast-growing plants that
can be broadly characterized as grasses or reeds, such as kenaf and
bamboo, which provide fiber with smaller associated environmental
costs than taking fiber from trees. A growing segment of the fiber
industry is based on the use of fiber from these plants. In many
cases the quality and consistency of fibers taken from these plants
(after processing) is as good as that provided by the wood pulp
industry. In addition, fiber is also widely available as a
by-product of agricultural production. Stalks, stems, and husks
from cereal grains, for example, are a ready source of fibrous
material that, while not as high in quality as the fiber taken from
wood or the better grass species, is extremely cheap and, as a
by-product, has essentially no additional environmental cost
(beyond whatever environmental costs are associated with the
production of the main crop).
[0057] The fibrous materials included in the formulations described
here vary greatly in both fiber length and fiber aspect ratio.
Overall, however, it is preferred that the materials have an
average fiber length that is less than about 2 mm and an average
aspect ratio that is in the range of about 5:1 to 25:1.
[0058] The preferred wax or wax emulsions in the formulation, used
to increase water-resistance, is a stable aqueous emulsion usually
made of carnauba, candelilla, rice bran, paraffin, or any other
food-grade wax: vegetable waxes are preferred over animal and
mineral waxes, and natural waxes are preferred over synthetic
varieties. The wax type is selected based on the particular
application and desired properties of the final product. The
emulsion is usually prepared by means of emulsifying agents and
mechanical agitation. Examples of wax emulsions suitable for use in
the present formulation include emulsified carnauba wax and
emulsified candelilla wax. Emulsifiers include all of those
permitted for food applications, including (but not limited to)
sorbitan monostearate, Polysorbate 60, Polysorbate 65, Polysorbate
80, food-grade gums (e.g., arabinogalactan, carrageenan,
furcelleran, xanthan), stearyl monoglyceridyl citrate,
succistearin, hydroxylated lecithin, and many other compounds. In
the alternative to wax, one may use an additive component or
emulsion thereof in an amount ranging from about 0.5% to about 10%
on a dry weight basis. The additive component can comprise an
epoxidized vegetable oil, a hydrogenated triglyceride, poly(vinyl
acetate), poly(vinylacetate-ethylene) copolymer,
poly(ethylene-vinyl acetate) copolymer, or a combination
thereof.
[0059] FIG. 2 depicts an exemplary base 20 in accordance with one
embodiment of the present invention. A hole 40 is localized in the
center of the base 20.
[0060] FIGS. 3 and 4 depict an exemplary packaging article having a
cover 10 and a base 20. In addition, FIG. 4 shows that, when
assembling the cover 10 and the base 20, protrusion 30 should be
connected with the hole 40.
[0061] FIG. 5 shows an exemplary packaging article having double
protrusions 31 and 32 and double holes 41 and 42.
[0062] FIGS. 6-17 further depict a number of exemplary packaging
articles that may be formed in accordance to various embodiments of
the present invention.
[0063] Although the invention has been described with respect to
specific embodiments and examples, it will be readily appreciated
by those skilled in the art that modifications and adaptations of
the invention are possible without deviation from the spirit and
scope of the invention. Accordingly, the scope of the present
invention is limited only by the following claims.
* * * * *