U.S. patent application number 10/179764 was filed with the patent office on 2003-01-23 for multilayer storage container.
This patent application is currently assigned to RUBBERMAID INCORPORATED. Invention is credited to Rodi, Gina, Shepler, William W., Skov, Erik.
Application Number | 20030015530 10/179764 |
Document ID | / |
Family ID | 23163819 |
Filed Date | 2003-01-23 |
United States Patent
Application |
20030015530 |
Kind Code |
A1 |
Shepler, William W. ; et
al. |
January 23, 2003 |
Multilayer storage container
Abstract
A multiple layer reusable plastic container is disclosed. The
multiple layer structure includes at least one layer of recycled or
highly economic material and at least one outer layer made from
either virgin resin or a more aesthetically appealing material to
provide a multiple layer reusable container that is economical to
manufacture in terms of material costs but yet has an acceptable
outward appearance. The recycled or economical layer may be coated
on both sides with virgin resin to provide an improved inner and
outer appearance to the reusable container and also qualify the
inner surface as an appropriate food contacting surface.
Inventors: |
Shepler, William W.;
(Brunswick, OH) ; Rodi, Gina; (Wooster, OH)
; Skov, Erik; (Akron, OH) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN
6300 SEARS TOWER
233 SOUTH WACKER
CHICAGO
IL
60606-6357
US
|
Assignee: |
RUBBERMAID INCORPORATED
Wooster
OH
|
Family ID: |
23163819 |
Appl. No.: |
10/179764 |
Filed: |
June 25, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60301540 |
Jun 27, 2001 |
|
|
|
Current U.S.
Class: |
220/62.22 ;
206/459.5; 206/505; 206/524.9 |
Current CPC
Class: |
Y02W 30/80 20150501;
Y02W 30/807 20150501; B65D 1/28 20130101 |
Class at
Publication: |
220/62.22 ;
206/524.9; 206/459.5; 206/505 |
International
Class: |
B65D 001/40; B65D
003/22; B65D 006/14; B65D 008/04; B65D 085/62 |
Claims
What is claimed:
1. A reusable, three-dimensional storage container comprising: a
first layer comprising a post-consumer or post-industrial regrind
resin selected from the group consisting linear low density
polyethylene, high density polyethylene, polyvinylchloride,
polyethyleneterephthalate, nylon and mixtures thereof, a second
layer comprising virgin resin tied to the first layer.
2. The storage container of claim 1 wherein the first layer serves
as an inner layer and the second layer serves as an outer
layer.
3. The storage container of claim 1 wherein the second layer
further comprises a colorant.
4. The storage container of claim 1 further comprising a third
layer comprising virgin resin material disposed adjacent the first
layer opposite from the second layer, the third layer being tied to
the first layer.
5. The storage container of claim 4 wherein the second layer
further comprises a colorant.
6. The storage container of claim 4 wherein the third layer further
comprises a colorant.
7. The storage container of claim 4 wherein the second and third
layers each comprise a colorant.
8. The storage container of claim 1 wherein a ratio of thicknesses
of the first to the second layer ranges from about 60:40 to about
80:20.
9. The storage container of claim 4 wherein a ratio of a thickness
of the first layer to a combined thickness of the second and third
layers ranges from about 50:50 to about 80:20.
10. The storage container of claim 1 wherein the first layer
further comprises a foaming agent.
11. The storage container of claim 1 wherein the first layer
further comprises calcium carbonate.
12. The storage container of claim 4 wherein the first layer
further comprises a foaming agent.
13. The storage container of claim 4 wherein the first layer
further comprises calcium carbonate.
14. The storage container of claim 1 wherein the container is
formed using a co-extrusion blow molding process.
15. A reusable, three-dimensional storage container comprising: (a)
a container portion comprising a first layer comprising a
post-consumer or post-industrial regrind resin selected from the
group consisting linear low density polyethylene, high density
polyethylene, polyvinylchloride, polyethyleneterephthalate, nylon
and mixtures thereof, a second layer comprising virgin resin tied
to the first layer, a third layer comprising virgin resin material
disposed adjacent the first layer opposite from the second layer
and tied to the first layer, the first, second and third layers of
the container portion being molded to form a bottom panel connected
to and disposed between two opposing side panel and two opposing
end panels, each side panel being disposed between and connected to
the opposing end panels to form an open top box structure, and, (b)
a top portion comprising a first layer comprising a post-consumer
or post-industrial regrind resin selected from the group consisting
linear low density polyethylene, high density polyethylene,
polyvinylchloride, polyethyleneterephthalate, nylon and mixtures
thereof, a second layer comprising virgin resin tied to the first
layer, a third layer comprising virgin resin material disposed
adjacent the first layer opposite from the second layer and tied to
the first layer, the first, second and third layers of the top
portion being molded to form a top panel that engages top edges of
the side and end panels of the container portion to provide a lid
for the open box structure.
16. The storage container of claim 15 wherein the second and third
layers further comprise a colorant.
17. The storage container of claim 15 wherein a ratio of a
thickness of the first layer to a combined thickness of the second
and third layers of the container portion ranges from about 50:50
to about 80:20 and a ratio of a thickness of the first layer to a
combined thickness of the second and third layers of the top
portion ranges from about 50:50 to about 80:20.
18. The storage container of claim 15 wherein the first layer
further comprises a foaming agent.
19. The storage container of claim 15 wherein the first layer
further comprises calcium carbonate.
20. The storage container of claim 15 wherein the second and third
layers comprise a resin selected from the group consisting of
polysulphone, polymethylpentene, polycarbonate, polyetherimide,
nylon, polyarylate, polyphenylsulphide, polyphenylene oxide,
polyethersulphone, polyethyleneterephtalate, aromatic polyketone,
liquid crystal polymer and mixtures thereof.
21. The storage container of claim 15 wherein the container portion
is formed using a co-extrusion blow molding process.
22. The storage container of claim 15 wherein the top portion is
formed using a co-extrusion blow molding process.
23. A lid for reusable, three-dimensional storage container, the
lid comprising: a first layer comprising a post-consumer or
post-industrial regrind resin selected from the group consisting
linear low density polyethylene, high density polyethylene,
polyvinylchloride, polyethyleneterephthalate, nylon and mixtures
thereof, a second layer comprising virgin resin tied to the first
layer.
24. The lid of claim 23 further comprising a third layer comprising
virgin resin material disposed adjacent the first layer opposite
from the second layer, the third layer being tied to the first
layer.
25. The lid of claim 24 wherein the second and third layers each
comprise a colorant.
26. The lid of claim 23 wherein a ratio of thicknesses of the first
to the second layer ranges from about 60:40 to about 80:20.
27. The lid of claim 24 wherein a ratio of a thickness of the first
layer to a combined thickness of the second and third layers ranges
from about 60:40 to about 80:20.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. .sctn.
119(e) of U.S. Provisional Patent Application Serial No.
60/301,540, filed Jun. 27, 2001, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] Reusable plastic storage containers are disclosed. More
specifically, reusable plastic storage containers having a multiple
layer structure are disclosed. Still more specifically, reusable
plastic storage containers are disclosed that have a multiple layer
structure wherein at least one of the layers is fabricated from
recycled plastic or other economical polymer material and wherein
at least one of the visible outer layers is fabricated from virgin
resin material.
[0004] 2. Description of the Related Art
[0005] Reusable storage containers are known. One common type of
reusable storage containers is fabricated from molded plastic in
the form of an open-top box with a molded plastic lid. Such
containers come in a variety of styles and colors.
[0006] One problem associated with currently available reusable
storage containers is the relatively high manufacturing cost.
Specifically, because the containers need to be aesthetically
appealing due to their extended use, virgin resins are typically
used in their fabrication. Colorants are added to impart any of a
variety of colors to the containers. Because of the aesthetic
appeal requirement, post-consumer regrind or post-industrial
regrind resins are generally unacceptable because these recycled
resins may include large quantities of contaminants, which give the
resulting product a speckled and inconsistent appearance. As a
result, the manufacturer may have to find a source or recycled
material or regrind resin of a higher quality or of a desired
color, which may drive up the cost of using a regrind resin.
[0007] Further, because reusable containers must be relatively
rigid to permit stacking and carrying of heavy items, large
quantities of virgin resins are used to fabricate a single
container and lid combination. Because the containers are typically
injection- or blow-molded, most of the cost of manufacture is tied
up in materials costs. As a result, the requirement that virgin
resins be used substantially drives up the cost of currently
available reusable containers.
[0008] As a result, there is a need for improved reusable plastic
container designs and methods of manufacture which can decrease the
cost of manufacture of these items.
SUMMARY OF THE DISCLOSURE
[0009] A more economical reusable three-dimensional storage
container is disclosed.
[0010] In one refinement of the disclosure, a reusable
three-dimensional storage container includes a first layer of a
post-consumer or post-industrial regrind resin selected from the
group consisting of linear low density polyethylene, high density
polyethylene, polyvinylchloride and polyethyleneterephtalate, and a
second layer of a virgin resin that is tied to the first layer.
Preferably, the second layer serves as an outer layer to provide
the requisite aesthetic appearance. However, it is anticipated that
the second layer might serve as an inner layer in the event the
reusable storage container is intended to hold food products and
therefore the second layer is intended to be a food-contacting
surface.
[0011] In a refinement, the container further includes a third
layer disposed adjacent the first layer, opposite from the second
layer. The third layer includes a virgin resin material, thereby
providing a reusable three-dimensional storage container having
three layers, two virgin resin layers which sandwich a recycled,
regrind or other economical polymer layer therebetween.
[0012] In a further refinement of the disclosed container, the
virgin resin layer(s) may include a colorant.
[0013] In still a further refinement of the disclosed container, a
ratio of the thicknesses of the first layer to the thickness of
either the single second layer or the combined thicknesses of the
second and third layers ranges from about 60:40 to about 80:20. As
a result, the bulk of the material used to fabricate the reusable
storage container is either a recycled resin or an economical resin
thereby substantially lowering the overall cost of the reusable
container.
[0014] The economical or recycled first layer may also include a
foaming agent to reduce the weight of the container or a filler
such as calcium carbonate which will reduce the molded part cooling
time.
[0015] Other advantages of the disclosed container will be apparent
to those skilled in the art from a review of the following figures
and detailed description taken in conjunction with the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The disclosed containers are described diagrammatically in
the following drawings wherein:
[0017] FIG. 1 is a sectional view of a multilayer material used to
fabricate a reusable storage container made in accordance with the
disclosure;
[0018] FIG. 2 is a sectional view of another multilayer material
used to fabricate a reusable storage container made in accordance
with the disclosure;
[0019] FIG. 3 is a front sectional view of a reusable storage
container and lid combination made in accordance with the
disclosure;
[0020] FIG. 4 is an end sectional view of the container shown in
FIG. 3;
[0021] FIG. 5 is an enlarged partial end view of the container
shown in FIG. 3;
[0022] FIG. 6 is a top plan view of the container shown in FIG. 3
with the lid removed;
[0023] FIG. 7 is a perspective view of the container shown in FIG.
3 with the lid removed;
[0024] FIG. 8 is a front sectional view of two reusable storage
containers as shown in FIG. 3 stacked one on top of another;
[0025] FIG. 9 is a sectional view of two parisons used to fabricate
a two layer reusable storage container in accordance with the
disclosure; and
[0026] FIG. 10 is sectional view of three parisons used to
fabricate a reusable container in accordance with the
disclosure.
[0027] The drawings are not necessarily to scale and that the
embodiments are sometimes illustrated by graphic symbols, phantom
lines, diagrammatic representations and fragmentary views. In
certain instances, details which are not necessary for an
understanding of the disclosed containers or which may render other
details difficult to perceive may have been omitted. It should be
understood, of course, that the disclosure is not necessarily
limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0028] FIG. 1 illustrates a two layer structure including a first
layer 20 tied to a second layer 21. In order to reduce
manufacturing costs, of which approximately 50% are due directly to
the cost of materials and colorant, the first, thicker layer 20 can
be fabricated from a post-consumer regrind or post-industrial
regrind resin such as linear low density polyethylene, high density
polyethylene, polyvinylchloride, polyethyleneterephthalate, nylon
and mixtures thereof. Other, inexpensive resins may also be used to
drive down the manufacturing costs, which will be apparent to those
skilled in the art. The thinner, second layer 21 is preferably
fabricated from a virgin resin to provide an improved outer
appearance to a container or to provide a satisfactory
food-contacting surface. Suitable resins for the second layer 21
include, but are not limited to, linear low density polyethylene,
high density polyethylene, polyvinylchloride,
polyethyleneterephthalate, nylon and mixtures thereof. Other
suitable resins will be apparent to those skilled in the art
depending upon the qualities desired (e.g., scratch resistance,
stain resistance, resistance to oxidation, etc.).
[0029] Often, it is desirable to have either an improved inner and
outer appearance to a reusable container or to provide an
aesthetically appealing outer surface wall providing a suitable
food-contacting inner surface. In such cases, containers can be
fabricated from the three layer structure shown in FIG. 2 which
includes a first layer 20, a second layer 21 and a third layer 22.
The layer 22 can be made from like or similar materials as used for
the layer 21 discussed above.
[0030] Suitable colorants for the outer and inner layers 21, 22
include, but are not limited to, various organic and inorganic
pigments dispersed in a polyolefin carrier. Further, to reduce the
weight of the overall structure formed, foaming agents can be used
in the layer 20. Suitable foaming agents include, but are not
limited to, citric acid mixed with sodium bicarbonate.
[0031] In addition, fillers may be added to the thicker layer 20 to
reduce the cooling time of the molded part, reduce the gloss or
sheen of the product and/or stiffen the resulting product. One
suitable filler is calcium carbonate. Other suitable fillers
include, but are not limited to, talc, barium sulfate, mica, glass,
clay, titanium dioxide, dolomite, wood flower and flax.
[0032] Other functional properties may be incorporated into the
inner and outer layers 22, 21, such as stain resistance. If stain
resistance is desired for either layer 22, 21, the layers should
incorporate a stain-resistant resin including, but not limited to,
polysulphone, polymethylpentene, polycarbonate, polyetherimide,
nylon, polyarylate, polyphenylsulphide, polyphenylene oxide,
polyethersulphone, polyethyleneterephtalate, aromatic polyketone,
liquid crystal polymer and mixtures thereof.
[0033] Further, fragrance can be added to any of the layers 20-22.
Suitable fragrance includes various fragrance oils dispersed in a
polyolefin carrier. Further, odor fighting additives, such as
sodium bicarbonate can be added to one or more of the the resins
utilized. Still further, using a foaming agent in at least the
middle layer 20, and perhaps the outer layers 21, 22, can increase
the insulating properties of the resulting container.
[0034] FIG. 3 is a partial elevational/sectional view of a
container 25 that can be fabricated from either the two-layer
structure of FIG. 1 or the three layer structure of FIG. 2 as
discussed above. Container 25 includes a lid 26 secured to an
open-top container 27. Container 27 includes bottom panel 28
disposed between and connected to opposing end panels 29, 31 as
well as side panels 32, 33 (see also FIG. 7). The container portion
27 typically includes handles 30, 34. Further, to enhance sealing,
the handles 30, 34 may include a bead 35, 36 around which a lip 37,
38 of the lid 26 is secured to provide a secure engagement. The
side panels 32, 33 may also include recessed sections 41-44 (see
also FIG. 7). The recess sections 41-44 enhance the structural
integrity of the container 27. Further, as discussed below with
respect to FIGS. 9-10, the recess sections 41-44 may also serve as
a transparent window to make it easy for the consumer to view the
contents of the container 27. Similarly, as shown in FIGS. 4 and 7,
the end panels 29, 31 may also include recesses 45, 46. As shown in
FIG. 8, the recesses 41-46 also enhance the stackability of two
light container portions 27a, 27b.
[0035] Turning to FIGS. 9 and 10, a preferred method for
fabricating the reusable containers disclosed above is a
co-extrusion blow molding process. In such a process, a parison 50
as shown in FIG. 9 is co-extruded so that it has an inner layer 20
and an outer layer 21 (see FIG. 1). The parison 50 may then be blow
molded into a three dimensional article such as the container
portion 27 or lid portion 26 of the container assembly 25 shown in
FIG. 3. In the embodiment shown in FIG. 9, clear resins are
provided at 51, 52 to provide a window at one of the recesses 41-46
of either the side panels 32, 33 or end panels 29, 31 as shown in
FIGS. 3, 4, and 7-8. Similarly, as shown in FIG. 10, a parison 60
may be provided with co-extruded layers 20-22 (see FIG. 2). Again,
clear portion 61, 62 may be provided for purposes of a viewing
"window" as described above.
[0036] The thickness of the layers 20-22 can vary, depending upon
the embodiment. Preferably, the thickness of the layer 20 is at
least twice as thick as the layer 21 in a two layer structure or
the layer 20 is at least twice as thick as the combined thicknesses
of the layers 21, 22 in a three layer structure. Suitable thickness
ratios of the thickness of the layer 20 to the thickness of the
layer 21 (two layer structure) or to the combined thicknesses of
the layers 21, 22 (three layer structure) can range from about
50:50 to about 80:20.
[0037] The foregoing detailed description is given for clearness of
understanding only, and no unnecessary limitation should be
understood therefrom, as modifications within the scope of the
invention may become apparent to those skilled in the art.
* * * * *