Note: Descriptions are shown in the official language in which they were submitted.
10 ' _ This invention relates to a package for two or more _
containers such as cans, bottles, jars, cannisters, made of
glass, metal, or rigid plastic or paper~ In a more specific
aspect the present invention relates to an improved ` .
I merchandising package for a plurality of such containers
! wherein performance,economy, and~appearance of the package
are primary considerations. -
Today's marketing of bottled and canned beveragesand other products calls for suitably packaged clusters
of such containers, perhaps the most familiar of which is
the so-called "six-pack". The package must safely and firmly
~ holdthe.containers, it must lend itself both to ready 1.
l independent portability for consumer use and to bulk
~ stacking for warehousing and shipment, and it must lend
.l itself to reliable and economical massproduction. The advent
1 of shrinkable plastic overwrapq has resulted in drastic
1~ changes from the cardboard packages of the past, and
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~ I U~ S Patents 3,532,214; 3,198,327; 3,552,559; 3,834,525;
Re 28,535; 3,650,39~; 3,650,395; 3,817,373; 3,416,288;
3,7~7,749; 3,331,503; 3,302,784; 3,477,56~; 3,756,397;
1 and 3,217,874 are representative of packages with plastic
1, overwrap. Most of these patents are concerned with the use
!l of various transparent, nonfoam shrink wrap packages and to
¦ the use of various handles, "fingerholes" and adjunct
supporting structures.
I Multicontainer packages using this transparent thermo-
I plastic films are suitable for many applications althoughthere are marked disadvantayes for the packaging of glass
' containers containing products such as beer which are
sensitive to light. Furthermore such thermoplastic films do
I not provide a great deal of cushioning protection in l~andling.
, It is also quite difficult to decorate such transparent
thermoplastic films and such packages often require the attachment
of supplemental labels for the purpose of identification
,; and decora~ion.
I It is noted that U. S. Patent 3,400,810 discloses
~ the use of foam polystyrene for shrink wrapping of multicontaine~
packages. However, the foam polystyrene disclosed in this
, patent is biaxially oriented and will shrink in both
directions. Such a shrunken overwrap will have the same
i~ strength properties in both directions making removal of the
l~¦ containers somewhat difficult. Furthermore it will be difficult to
form a seal on the end flaps of package cluster due to axial
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~ as well as circumferential shrinkage of the overwrap. It is noted,
¦. that the pac~ages illustrated in this patent engage only a
small fraction of the end containers in the cluster. Moreover
1. it is necessary for the patentee to use a very thick film
¦' in the neighborhood of 40 mils to achieve the required
strength.
¦~ Thus it is the primary object of the present invention
~¦ to provide an improved multicontainer merchandising package
l~ which is strong but yet is easily opened, opaque to light I
I and is capable of being preprinted with information or
decoration prior to application and requires no external
structure for handling purposes.
In attaining the objects of this invention, one feature
resides in a multipie container merchandising package com-
prising a group of similarly shaped containers held together
. in side-by-side fashion by a plalstic overwrap comprises an
opa~ue~ uniaxially oriented, laminated composite
sleeve which is uniaxially oriented in the circumferential
directi.on and comprises a closed cellular (i.e. foam)
~ thermoplastic polyolefin layer laminated to a noncellular
thermoplastic polyolefin film, said sleeve circumscribing
the containers and snugly engaging the tops of the containers
1 in shrink fit relation.
¦. An essential feature of the present invention is in the
1 composition of the heat shrin~able polymeric sleeve, which is
of a composite ~tructure having a layer of a cl e_ cellular
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i (e.g. foam) olefin polymer adhered to a layer of a noncellulax
olefin polymer film wherein the cellular layer is in on the
inside of the sleeve and in engagement with at least the tops
Il of containers and the film is on the outside of the sleeve
5 11 and has a smooth, glossy decorated surface.
¦~ other objects, features, and advantages of the present
¦i invention will be apparent from the description and draw-
¦, ing~ which follow wherein
~ Fig. 1 is a perspective illustration of a "six-pack"
I of glass bottles packaged in accordance with the present
invention;
' Fig. 2 is a bottom view of the package of Fig. l;
¦~ Fig. 3 is a perspective illustration of a six-pack
~l of cans packaged in accordance with the present invention;
' Fig. ~ is a perspective illustration of a 12-pack of
glass beer bottles packaged in accordance with the present
invention; and
,~ Fig. 5 is a cross sectional illustration of the composite
' laminate used as the overwrap in Figs. 1 through a,
¦ Referring now to Figs. 1 and 2 reference numeral 10
generally refers to the cluster package of six conventional
upstanding one-way beer bottles 15 having similar cylindrical
bodies. The containers are arranged in two adjacent rows
~ each having three side-by-side containers.
~ As can be seen in Fig. 1 the tops 12 of the bottles 15
,~ are snugly engaged by sleeve 11 and the bottles are contained
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and confined in all directions so as to prevent relative
movement of the individual containers within the package. Fig.
2 illustrates how the bottoms 16 of bottles 15 are also snugly
, engaged by the sleeve~ The heat shrunk opaque, overwrap
' sleeve of invention is indicated by reference numeral 11 and
I is applied so that the direc-tion of uniaxial orientation is
¦ in the circumferential or radial direction oE the sleeve.
Sleeve 1~ is shown with decoration generally indicated by the
, letter "X". Such decoration is applied prior to wrapping the
~ sleeve around the package.
The sealing seam of the sleeve is designated by lla and
is shown as being positioned on the lower sicle of the package.
The seam is formed by the use of adhesives or by th~rmall~
! fusing edges of the sleeve together. The seam is positioned
15 ~ on the side of the package as a matter of convenience and
could also be located at the bott:om or top oE the package.
The open end of the sleeve 11 defi~Qs an aperture 13 which
is formed as the overlaying ends of the sleeve shrink and use
, together. The other end of the package (not shown) has similar
configuration and appearance. In forming aperture 13 there
I is some shrinkage in the sleeve (e.g. less than 10~) in the
f axial direction and this assists in the formation of the tight
package. IE there were too much shrinkage in the axial direction,
~ the aperture would be too large, and the sleeve would not
25 ~ effectively retain the bottles~ In this regard it is important
that the sleeve extend to cover the point of farthest extension ,
i of the container from the package so as to prevent container-to- !
container impact when several of such packages are transferred
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in end-to-end fashion on a conveyor. This point is approximately~
designated by the lead line for reference numeral 13 in 1-
Fig. 2,
~ The upper rim 13a of aperture 13 is quite functional and
5 ,' serves as a convenient gripping surface for transporting the
package. Due to the nature of the uniaxially orientation,
rim 13a is quite strong against the stress of lifting at this
point and readily supports the weight of containers and their
I! contents.
10 i To open the package all one need do is punch a hole with
the inger or other instrument through the top of the package
at point between tops 12 where the sleeve is tightly drawn.
Such a point is generally illustrated by reference numeral 14.
Once the sleeve ispunctured in these areas it will readily
tear in the circumferential direction and the bottles can ~e
easily removed individually or in pairs. The sleeve is quite
resistant to tearing in the axial direction so the package
remains intact with respect to the remaining containers in
~ the cluster.
20 , ~ig. 3 generally illustrates a package 20 similar to
` that shown in Figs. 1 and 2, except that the containers are
in the form of cylindrical metal cans 21 rather than bottles.
The sleeve 23 is otherwise as explained with respect to Figs.
' 1 and 2 and is sealed together at seam 22,
Fig. 3 also illustrates how finger opening can be used
1 with the package of invention if desired although the finger hole~
¦~ is not used in the presently preferred embodiment. Reference
numeral 25 represents a ~inger slit which is cut in the
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circumferen-tial direction on sleeve 23. The slit ~erminates
in semicircular cuts 25a which serve to retard tearing in
the circumferential direction upon carrying. It will be
~ understood that some care must be exercised when carrying the
5 ¦I package by finger slits. Reference numeral 24 represents
¦` another type of circumferential finger slit which is formed
¦~ by pushing a hot loop of wire through the sleeve. Slit 24
¦, is sealed by beaded edges 24a which are formed by contact
I with the hot wire. In practice it is likely that all the
10 ¦ slits on one package will be of the same type.
~I Fig. 4 generally illustxates a 12-pack 30 of one-way beer
¦ bottles arranged in three rows of four bottles each confined
¦ by sleeve 30 in tray 32. The package configuration is generally
¦` the same for that shown in Figs. 1 and 2 except that the
15 1 bottoms of containers 31 set in tray 32 whlch is shown as being
made of corrugated fiber board. The outline of tray 32 is
generally seen under the sleeve 30 and comprises a flat bottom
,; panel provided with short upstanding side walls on all sides.
l~ Tray 32 i5 used for added package rigidity when more than two
20 , rows of containers are packaged to prevent relative displacement
~ of the packaged containers with respect to each other. Due to
,~ the use of tray 32 only the tops 34 of the bottles are snugly
engaged by sleeve 30 and the bottoms of the containers are
, held securely against the tray~
25 ¦ Sleeve 30 is applied so that the direction of uniaxially
orientation is in the circumferential or radial direction of the
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sleeve and two sealing seams 33 are shown as being positioned
on the lower part of the package overlaying the side wall portion
! of the tray 32. In this embodiment the sleeve is applied
j, and sealed as two separate sheets, That part of the sleeve
¦ covering the bottom of the tray need not ba foamed and can be
I any compatible thermoplastic film. In some embodi~ents it may
¦ be preferred to use a less expensive non-decorated thermoplastic
¦ film for covering the bottom of the tray. Furthermore txans-
I parent films can be used to cover the tray bottoms when it is
I desired or required to read specifications or other information
printed on the tray bottom. As a further embodiment the sleeve
can be formed by sealing the composite to the tray at the point
I where sealing seama~ 33 are located. In this embodiment the
¦ hottom of the tray serves as a part of the sleeve. It is thus
15 ll apparent that the entire sleeve need not be made of the composite
I so long as the composite circumscribes the containers and snugly
i engages the tops of the containers in shrink fit rela~ion. In
this regard the term sleeve as used herein refers to this
jl relationship.
j As has been previously described with respect to Fig. 1 the
¦I rim 35 oE the aper-ture 36 in the end of sleeve 30 provides a
! convenient handle for carrying. Most 12-packs would probably
¦¦ be too heavy to permit the use of finger holes. The end of the
¦I package which is not shown is identical in configurati~n to the
1'i end shown.
Fig. 5 shows a cross sectional view of the sleeve of Figs. 1 ¦
j through 4 with 40 representing the foam or cellular layer and
¦41 representing the noncellular film laminated thereto. The total
I thickness of the lamina~e composite is usually in the range of a-
~¦ bout 3 mils to about 20 mils and preferably in the range of about
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5 to abou-t lS mils for efficiency and economy. The ce~lular lay r
40 is usually about 2 to about 5 times and preferably about 3 timls
the thickness of noncellular film 41 and noncellular layer
; 41 is usually positioned on the outside of the sleeve.
5 ` The polymeric materials respectively and independen-tly
contemplated for cellular layer 40 and noncellular layer 41
are olefin polymers; that is, each of these polymeric layers
I will have as the predominant polymeric moiety a polymar of an
I ¦ olefin, preferably an olefin having 2-4 carbons, or mixtures
¦ thereof, e.g. the predominant moiety will be a polymer of
ethene, propene, butene, like butene-l, or mixtures thereof,
more commonly referred to as a polymer of ethylene, propylene
or butylene. This includes homopolymers, copolymers of these
Il olefins with other copolymerizable monoethylenically unsaturated
15 !I monomers, wherein the olefin in the copolymerization is such
li that the moiety thereo~ in the final copolymer, that is the
~I ethylene, propylene or butylene moiety, is at least about
1 60% by weight, and polymeric blends, or admixtures, wherein
~ the resulting polymeric blend is at least about 60~o by weight
of a polymerized olefin moiety, e.g. at least about 60% .
of an ethylene moiety in the blend. The minor amounts,
i.e. less than about 40% of the other moiety of material
employed, are such as to supplement and compliment the basic
' properties of the olefin polymer and this applies whether
other moieties are introduced by way of a polymer blend,
i or admixture, or by way of a copolymerized monomer. These
other moieties, whether supplied by blending another polymer
, with a homopolymerized olefin, e.g. homopolymerized ethene,
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(ethylene homopolymer), or by copolymerization therewith,
should not be such as to significantly interfere with the
foamable, heat sealable, heat shrinkable, extrudable
characteristics of the base olefin polymer and should be
~ compatibLe~ i.e. miscible with it.
Exemplary alefin homopolymers are ethylene, propylene
and butylene homopolymers, with the former being especially
preferred, and blends of these homopolymers. The terms
I polyethylene, polypropylene and polybutylene are used herein
to include those materials recognized and sold commercially
under those names, even though those materials~ strictly
and technically, may be viewed by some to be a blend, or
i copolymer, since the materials may include small amounts,
, typically less than about 55~, e.g. 0.5-3~ by weight, of
another polymeri~ moiety~ For examp:Le, ~olyethylene is sold
and recognized by that name when in fact it may be produced
by copolymerization with 1-2 percent by weight of hexene,
or butadiene, or may, by analysis, show several percent,
e.g. 3-5~ of vinyl acetate moiety, for practical purposes
` 20 ~ however these materials consist o~ polyethylene. In this
regard the composition of the sleeve used in the present
`i~ invention is the same composition as the laminate described
in commonly assigned United States Patent 4,038,446 -
I entitled "Container with Improved ~Ieat Shrunk
l Cellular Sleeve".
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The foregoing generally describes the composition of
the polymeric portion of the cellular layer 40 and noncellular
, film 41, it being understood that the layers need not be of the
¦I same polymeric composition. It will, of course, be apparent
5 ¦I that suitable adjuvants can be present in these layers if
desired. Thus, for example in addition to the polymeric
material, the respective layers can include pigments, stabilizers
and the like. Generally, excellent results will be obtained
I by selecting a polymeric composition for cellular layer 40
1~ ~hich has a melt index or melt flow of less than 5, for exam.ple
I between about 0.1 to 5 and most desirably about .2 to 1 and
¦ the polymeric material selected ~or the noncellular layer 41
will have a melt index or melt flow of less than about 10.
1 The preferred material for both the cellular layer and the non-
15 1 cellul.ar layer is polyethylene, which includes low density, polyethylene, for example polyethylene having a density of
. , less than 0.925 grams/cc, generally in the range of about
! 0.910 to about 0.925, high density polyethylene, for example
!~ that havin~ a density greater than about 0.941, typically
20 ~. about 0.941 to about 0.965, madium density polyethylene, and
~! blends thereof. As regards the cellular layer, the density
; specified is prior to foaming. The foamed density of cellular
Il layer is about 25-30 #/ft.3 and the density of the composite
I. laminate is about 35-40 #/ft.
25 i1 As previously indicated the present invention i5 directed.
to an improvement in th here~nbefore-de~cri~ed pac~a~
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wherein, in producing these packages, a heat shrinkable
uniaxially oriented, laminated sheet is first prepared
which is appropriately cut and slit and formed into rectilinear
¦I sheets which are then formed into a heat shrinkable sleeve
5 ¦¦ which applied to the cluster of containers to produce
¦l, the ultimate packa~e. While a sheet of stock material of the
~¦ composite structure for use herein can be formed by various
techniques it is generally preferred to employ extrusion
¦I technology. This extrusion technology may take either of
¦I two conventional forms, one of which is extrusion coating
and the other of which is the use oE co-extrusion technology~
The latter technique, however~ is particularly highly preferred
I because of the apparent ability to form lower density
¦ composite structures. In -the co-extrusion technique, while
15 I~ a slit die may be employed, the preferred practice is to employ
¦ an extrusion die which is possessed of an annular, circular
¦l opening and the composite structure is initially formed as
I' a tubular shape by what is referred to in the ar-t as a "blown
I bubble" technique. These types of co-extrusion dies are
1~ widely available commercially and an exemplary die is set forth
, in SPE Journal, November 1969, Vol. 25, page 20, entitled,
¦~ "Co-Extrusion of Blown Film Laminates" and form no part
of the present invention as such.
1~ In this known co-extrusion technique the circular openiny
l is fed from two independent extruders and, in this particular
~ instance, the e~trud-r supplying the ~oamabl~ material,
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intended to form cellular layer ~0, preferably will feed
j the die so that this material forms the internal portion
. of the tubular e~trusion; the extruder feeding the material
1 intended to form non-cellular layer 41 will preferably
be fed to the die so as to form the external portion of the
tubular shape. The tubular member issuing from the extruder
is blown into a bubble by conventional "bubble" forming
techniques, including air cooling of the external surface
thereof, and is then drawn through the nip of two juxtaposed
~ rollers wherein the tubular member is compressed to form
a flattened tube.
I Suitable convention foaming or blowing agents are employed
¦ to produce foaming and the cellular structure results,
ll just as the extrudate leaves the die~ This flattened
~ tube is then contacted with cutt~ing knives which slit the
flattened tubular member along its edges (machine direction)
, so as to form a sheet or film of substantially uniform
- , width; this sheet or film, which is at this point actually
~ a sheet of two superimposed composite structures, for use
j~ herein, is separated into two independent sheets and wound
. onto independent windin~ wheels, which provides the stock of the
.' heat shrinkable composite structure for use herein. Inasmuch
l! as the sheet of the composite structure must possess heat
!~ shrinkable characteristics the appropriate heat shrinking
,. in the machine direction of extrusion, whlch preferably
! is a major amount and is greater than the cross. direction
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heat shrinkage, is primarily provided by the impetus of the
I rate of drawing of the flattened tube through the nip of the
j rolls, and using cooling air on the exterior of the bubble,
l~ and the cross direction shrinkage, which is less than the machine
I direction shrinkage, is primarily provided by the internal
¦ air employed in forming the bubble and ex-ternal cooling
air. This of course is known for forming heat shrinkable
films.
I The term "heat shrinkable" as used herein refers to
¦ the property of the laminated composite whereby it contracts
¦ in length and/or width upon exposure to suEficient heat.
¦ Shrinking is generally attributable to a reorientation of
¦ molecules which were previously oriented by stretching the
i sheet either uniaxially longitudinally (machine direction)
or horizontally (transverse direction) or biaxially (both
directions). In the practice of the present invention the lamina ed
composite sleeve is said to be uniaxially oriented in the cir-
cumferential direction. This means that the sleeve is capable of
~ shrinkage in circumferential direction of at least about 2.5
20 1 times and preferably at least about 5 times the shrinkage in the
!l axial direction. The sleeves of invention are capable of shrin~in ~at
¦~ least 50~ and pref~rably at least 60~ in the circu~Ecrential ¦
ll direction and less tha~ 20~ and preferably less than 10~ in ¦
¦~ the axial direction. In a particularly preferred embodiment the ¦
25 ¦¦ sleeve is capable of ~hrinkage about 70~ in the circumferential dl-
¦~ rection at about 6-8~ in the axial direction. This shrinka~e value is
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theoretical ~alue rather than value which is experienced
in forming a package. The theoretical. values are determined
I' by placing a sample of the composite ir~ a hot bath of heat
¦', transfer liquid at 350F for 10 seconds and determining the
5 ¦I resulting shrinkage~ In actual practice the shrinkage is
usually much less than theoretical due to the amount of the
¦ composite that is used to wrap the containers. For example
a sheet of composite foam polyethylene and film polyethylene
with a foam thickness of about 4.5 mils and a film thickness
10 ¦ of about 1.5 mils, which is 21.5 inches long and about 11.5 inche 3
wide forms the sleeve around a si~-pack of one-way beer
bottles when heated at 400F for 20 seconds.. In such
a package there is an actual shrinkage of about 50~ in forming
. the aperture at the end of the pack, about 15~ between bottles
lS 1,' and on:ly about 2~ over the bottle tops.
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The term "heat shrunk" describ-es the condition of a
Il heat shrinkable material after application thereto of
3I heat sufficient to cause relaxation and shrinkage (e g.
heating in an oven at 450F for about 5 seconds). This heat
~3 treatment heats the sleeve to near the melting point of the
¦ composite.
¦ The sleeve can be applied by conventional method wherein
a plurality of containers are carried along a predetermined
1 path which can be a pair of moving conveyors or other
10 '! transport means to an arranging zone such as an indexer
wherethe containers are arranged in the desired juxtaposed
I relation. Typically this relation is three rows of
¦ containers two abreast. The arranged containers are moved
I along a path away from the arranging station to a wrapping
station where heat shrinkable composite laminate from a
supply roll is placed around the arranged containers. The
Il wrap is parallel to the longitudinal axis of the arranged
¦I container cluster or provided the ends of the outermost
~I containers are within the volume defined by the sleeve
20 l after shrinkage.
, The wrapped containers are then passed through a heating
zone such as a shrink tunnel where heat sufficient to
~j shrink the film is applied. The arranged containers held
Il endwise and sidewise by the heat shrunk sleeve are then
25 ,, passed to a distribution area.
Elor convenience in disclosure, all paten-t documents and
publications mentioned herein are inco orated by reference
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