U.S. patent application number 13/884079 was filed with the patent office on 2013-10-10 for machine and system for applying container carriers to containers.
This patent application is currently assigned to British Polythene Limited. The applicant listed for this patent is Stephen Paul Bates. Invention is credited to Stephen Paul Bates.
Application Number | 20130263557 13/884079 |
Document ID | / |
Family ID | 43467169 |
Filed Date | 2013-10-10 |
United States Patent
Application |
20130263557 |
Kind Code |
A1 |
Bates; Stephen Paul |
October 10, 2013 |
MACHINE AND SYSTEM FOR APPLYING CONTAINER CARRIERS TO
CONTAINERS
Abstract
A container packaging system for containers applies an apertured
plastics film carrier stock to substantially identical containers
such as beverage cans having annular chimes, cylindrical side
walls, and frusto-conical walls between the chimes and the side
walls. The carrier stock has shaped apertures to securely retain
drinks cans, food cans, bottles and similar containers, as a
multi-pack unit. The carrier stock is rolled onto suitably
juxtaposed containers engaging a tabbed aperture edge portion
progressively from above to below the upper edge of the respective
containers to be multi-packed and assumes a waveform 3D
conformation to unitise the containers. The rolling method
contrasts prior stretch application methods and enables cheaper and
thinner carrier stock to be used.
Inventors: |
Bates; Stephen Paul;
(London, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bates; Stephen Paul |
London |
|
GB |
|
|
Assignee: |
British Polythene Limited
London
GB
|
Family ID: |
43467169 |
Appl. No.: |
13/884079 |
Filed: |
November 23, 2011 |
PCT Filed: |
November 23, 2011 |
PCT NO: |
PCT/GB11/52306 |
371 Date: |
June 25, 2013 |
Current U.S.
Class: |
53/398 ;
53/48.4 |
Current CPC
Class: |
B65B 17/025
20130101 |
Class at
Publication: |
53/398 ;
53/48.4 |
International
Class: |
B65B 17/02 20060101
B65B017/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 23, 2010 |
GB |
1019848.9 |
Claims
1. A machine for applying a container-unitising film to containers
by use of a roller, the container-unitising film comprising: a
plastics sheet material comprising a number of apertures for
holding a number of containers together, the apertures extending in
at least a first direction; wherein the apertures have a centre and
wherein the edges defining the apertures have a geometry which
comprises a plurality of tabs facing the centre, the tabs being
defined by innermost edges separated by troughs, the troughs
defining a root at a maximum point from the centre; wherein the
innermost edges and the roots lie, respectively, on first and
second circumferences relative to the centre, the second
circumference being equal to or greater than a beading
circumference of a container; the configuration of the apertures
being such that, upon placement about a container, the innermost
edges of the tabs engage with said beading of such a container as
the troughs are urged downwardly and outwardly and the apertured
sheet material elastically forms a three dimensional structure,
wherein the machine comprises a conveyor system for the transport
of containers; and the conveyor system being operable to feed the
containers to an accumulation position and operable to convey the
containers towards an application station comprising said roller
for application of the apertured sheet to the containers, the
roller in use receiving apertured sheet material from a supply
system and urging the apertured sheet material onto the containers
such that each container is received in an aperture whereby the
sheet material forms the three dimensional structure.
2. The machine according to claim 1 wherein the conveyor and roller
are positioned and operable such that, as the conveyor moves the
containers, the rims of the containers are presented to the stock
of apertured plastics, and an inside tab edge of the aperture abuts
against an underside edge of a bead of the container, and as the
roller continues to move, the side edges of the aperture diverge
elastically to surround the sides of the container beading until
the inside edge of the aperture opposite the first engaged side of
the aperture is adjacent the rim and causes an inside edge of the
inside tab edge of the aperture to engage with an underside of the
rim, whereby to secure the apertured film upon the can.
3. The machine according to claim 1, wherein the conveyor moves the
containers to an accumulation position prior to being presented to
the application station.
4. The machine according to claim 1, wherein there is a cutting
apparatus, said cutting apparatus being operable to enable
appropriate pack sizes to be produced.
5. The machine according to claim 1, wherein there is provided a
plurality of co-operating sheeting supply mandrels whereby to
provide a continuous supply of sheeting to the roller, to enable a
seamless connection of separate sheets to provide effective
continuous operation of the system.
6. The machine according to claim 1, wherein the carrier film is
made from the group comprising polyethylene, polyethylene
derivatives and plastics materials with similar mechanical
properties.
7. The machine according to claim 1, wherein the carrier film is a
plastics film of less than about 350 .mu.m thickness.
8. The machine according to claim 1, wherein the carrier film
apertures are dimensioned to fit around cylindrical walled
cans.
9. The machine according to claim 1, wherein the carrier film
apertures are dimensioned to fit about reduced chime or necked
cans.
10. The machine according to claim 1, wherein the carrier film
apertures are dimensioned to fit about beading around the neck of a
bottle.
11. The machine according to claim 1, wherein the stock comprises a
length of single-rank apertured film.
12. The machine according to claim 1, wherein the stock comprises a
length of multi-rank apertured film.
13. A method of unitizing containers, utilizing the machine of
claim 1, comprising the steps: receiving a can; urging an inside
edge of a tab of an aperture toward an under-chime edge of the can;
easing adjacent side tabs of the aperture over the corresponding
rim parts of the can until the inside edge of the aperture opposite
the first engaged side of the aperture is adjacent the rim; and
causing an inside edge of the last tab to engage with an underside
of the rim, whereby to secure the apertured film with the can.
14. The method according to claim 13, wherein the urging of an
inside edge of a tab and easing of adjacent side tabs is realised
by use of an application roller of the machine which roller
cooperates with the container upper edge to locate and present an
inner edge portion of an aperture of the carrier stock sheet film
to the upper edge and progressively move that edge portion below
the container upper edge until the whole inner aperture edge
becomes located below that container upper edge.
15. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method and system for
applying container carriers to containers and to packaging systems
for containers and using the same for packaging containers. This
invention also pertains to a flexible carrier stock for machine
application to substantially identical containers such as beverage
cans having annular chimes, cylindrical side walls, and
frusto-conical walls between the chimes and the side walls, and
bottles with a neck ridge or seal beading. In particular, the
present invention relates to the machine application of a plastics
film having apertures to securely retain drinks cans, food cans,
bottles and similar containers, a unique method of applying the
film to the containers, the resultant combination providing a
multi-package or unitised pack.
BACKGROUND TO THE INVENTION
[0002] It is common practice to package beverages such as sparkling
fruit juices, cola drinks, beers and the like in cans, typically
being manufactured from pressed aluminium or plated steel, the
thickness being of the order of 50 .mu.m or so. These cans are
typically sold in four (2.times.2)- or six (3.times.2) packs. Early
examples of packaging such packs utilised cardboard which enveloped
the cans. In the 1950's plastics film container carriers were first
promulgated. The early forms of plastics film container carrier
utilised apertures which were deformed upon application of the
sheet over the cans, whereby the film formed a continuous flange
area about the side of the can. The films were placed about the top
of the can, underneath a beaded edge formed at the junction of the
lid of the can. Such early forms of carrier film allowed the cans
to be pulled through--albeit with some difficulty--but a reverse
movement of the can with respect to the carrier would mean that the
plastics flange would abut the bead and further movement required a
considerable force to release the can.
[0003] FIG. 1 shows an example from U.S. Pat. No. 2,874,835 (ITW)
which provides a carrier 30 comprising a flat sheet of plastics
material which is provided with a plurality of apertures 32. The
apertures are distinctly smaller (>20%) than a diameter of a can
retained by the carrier. FIG. 1a shows how cans, in use are
retained, with the circumferential inner edge of the plastics
apertures engaging with a lower edge of rim 46. It can be seen that
the plastics carrier material is substantially deformed by
stretching--after considerable forces have been applied--such that
the edge of the aperture is perpendicular to the plane of the
plastics carrier period to placement of the cans, especially with
reference to feature 40 in FIG. 1 b. Indeed, U.S. Pat. No.
2,874,835 indicates that extraordinary force is required for the
cans to come loose from the retainer device accidentally. The
disclosure of U.S. Pat. No. 2,874,835 indicates that polyethylene
is a preferred plastics material, which is stamped in a press to
form the apertures. This example taught of additional holes through
which the ends of an elongate handle can subsequently be inserted.
These plastics films--commonly referred to as carrier stock--are
stretched beyond their elastic limit. That is to say the size of
aperture will in turn stretch into shapes which are complimentary
to the shapes of the container (per U.S. Pat. No. 4,250,682 (ITW)).
After a container is removed from the carrier, the carrier cannot
be re-used due to the permanent stretching deformation during the
application for packaging purposes.
[0004] The carrier stock is typically polyethylene and early
examples were of a thickness of 500 .mu.m or more, although it is
typically 400 .mu.m or more for rim applied carriers.
[0005] The forces necessary to enable the plastics film to engage
with the sides of a can were considerable and, of course, the large
forces that were utilised to pack the containers together resulted
in problems in a consumer accessing an individual can. GB 1 200 807
(ITW) introduced slits in apertures, but forces of application were
still considerable since the apertures were "significantly smaller
than the diameter of a can with which the carrier film is to be
assembled" and therefore were still stretched beyond the elastic
limit of the material.
[0006] U.S. Pat. No. 2,997,169 taught of a solution to the problem
by the inclusion of tear-off tabs 72b; per FIGS. 2a & 2b, where
pre-stressed members associated with tab portion enabled a tear in
the plastics retaining film, which was considered easier than
forcing the rim of the can around the already stretched plastics
film. The cans are of a greater diameter than the apertures and,
accordingly, stretch the apertures and deform the material adjacent
into a frusto-conical shape whereby the cans are aggressively
retained against withdrawal in the direction opposite to that in
which they have been inserted.
[0007] U.S. Pat. No. 2,936,070 teaches of a still further patent,
the teaching of which was to address that a plastics carrier that
provides a gripping section not susceptible to loss of a can
through twisting and bending movements. With reference to FIGS. 3a
and 3b, resilient, flexible fingers 28 were forced upwardly (as the
plastics film is placed upon a number of cans during packing), the
fingers being determined by roots 30 defined partway into an inside
edge portion of an aperture. FIGS. 3b and 3c show the teaching from
this prior retainer in side views, where the rounded crenulations
28 are clearly visible. U.S. Pat. No. 2,936,070 states, in
particular, that the root diameter is less than the diameter of the
cans and a considerable stretching force is, nonetheless, applied
to the plastics material in the vicinity of the roots in stretching
the material into the frusto-conical, almost cylindrical
conformation shown in FIG. 3c. The description further discloses
that "the carrier can be assembled with cans with considerable
facility, simply by stamping the carrier down over the proper
number of cans. The cans simply cam into the apertures, deflecting
the fingers . . . whereby the cans are gripped aggressively with
the fingers abutting beneath the can beads". Indeed, the stamping
forces would have been considerable.
[0008] Further developments included various modifications: one
proposal for an article carrier was formed from a tube which was
alternately slit from side-to-side in a manner leaving un-slit
connecting portions at subsequent alternate opposite sides whereby
successive sections of the tube may be folded relative to each
other generally into a common plane for receiving the articles to
be carried. In order to economize on material, it is generally
desirable to make the wall of the tube as thin as possible
consistent with the required strength and durability. Thus, in such
heretofore proposed structures, immediately adjacent articles in a
package are spaced from each other at the area of contact with the
carrier only by a double thickness of the relatively thin material.
It was found that such spacing is, for many purposes, insufficient
since, in practice, the closely adjacent articles such as bottles
or cans would rub against each other so that the respective
surfaces may be scratched or otherwise defaced. For example, it is
common practice to apply a label or other decorative design by
lithography or other means to beverage cans and such labelling
would be damaged if the cans were permitted to rub together unduly
such as when the package was subjected to continual motion or
vibration during transport. U.S. Pat. No. 3,924,738 provided a
solution to this problem by forming longitudinally extending rib
means whereby to provide a separation spacing between cans, as
shown in FIG. 4.
[0009] U.S. Pat. No. 3,968,621 taught of manufacturing a carrier by
the formation of an extruded net, which net was subsequently
flattened by the use of a roller to produce an apertured film of
carrier stock, as shown in FIG. 5.
[0010] U.S. Pat. No. 3,317,234 teaches of a packaging system using
an upper laminate and a lower laminate. As seen with reference to
FIGS. 6a and 6b, the upper laminate comprising a first, continuous
plastics layer and a second laminate comprising an apertured card
layer is placed over and arrangement of bottles. The apertures of
the card layer are arranged to fit over respective metal cap of a
drinks bottle, the peripheral edges of the apertures being arranged
to engage with the underside of the metal cap, whereby to retain
the upper part of the bottle. The lower laminate being arranged to
act in a similar fashion with a bottle having a characteristic
waist, about which a card member of the second laminate could
engage, in conjunction with a plastics layer, which enveloped a
lower portion of the bottle. In a similar fashion, cans were
retained by substantially similar first and second laminates, the
card element of which engaging with a body-directed edge of the
respective upper and lower rims of a double rimmed can.
[0011] In the early 1980's, there was a shift in the method of
applying film stock to cans and the like. Previous forms of strip
stock for circularly cylindrical containers had been provided with
substantially circular apertures. In contrast teachings equivalent
to or derived from U.S. Pat. No. 4,219,117 (ITW), proposed carrier
stocks which were designed for application by dedicated jaw and
drum machinery (such as described in U.S. Pat. No. 4,250,682).
These proposals related to stock that had integrally joined band
segments defining can receiving apertures in longitudinal rows and
transverse ranks. The band segments included generally longitudinal
outer segments with each outer segment partly bounding the can
receiving apertures in an outer row. The apertures defined in such
stock are generally of a triangular/D shape, primarily to assist in
the mechanical placement of the stock around the rim of a can,
which mechanical application necessitated the use of mechanical
fingers which generally prevented the simultaneous use of such
devices in any configuration other than in the provision of
two-rank longitudinal rows. That is to say the cans are attached
with two cans being in a side-by-side arrangement: the systems are
limited in use and generally could not reliably operate to provide
cans packed, for example in 3.times.3 or 3.times.4 or 4.times.4 etc
arrangements.
[0012] In the carrier stock illustrated and described in the U.S.
Pat. No. 4,219,117, the band segments also included inner segments
partly bounding the can-receiving apertures, along with
transversely extending segments joining the inner segments, for
finger-hold grip elements.
[0013] Can manufacturers have in the past introduced cans having
smaller chime diameters, as compared to the diameters of the side
walls. Cans of this type are known as "necked-in" cans. The newest
versions of these necked-in cans further and drastically reduce the
ratio of the chime diameter and the side wall diameter. When stock
is applied by known procedures, the band segments defining the can
receiving apertures grip the frusto-conical walls of the cans
tightly and engage the lower edges of the chimes.
[0014] In a necked-in can of a newer type, the frusto-conical wall
between the chime and the side wall defines a conical angle greater
than approximately 28.degree. and in some instances as great as
approximately 37.degree.. When the frusto-conical wall defines such
a large angle relative to the can axis, it is difficult to apply
carrier stock since the band segments defining the can receiving
apertures have an undesirable tendency to slide up the cans and to
rest on the cans above the lower edges of the chimes. This tendency
is enhanced due to the jaw application system mentioned above.
[0015] A further problem of known systems, where great forces have
been used to apply the carrier stock, that they can be difficult to
remove--not only by accident--in use, especially by youngsters,
which has caused effervescent spillage to occur since the removal
by force of a drinks can from a carrier strip has resulted in an
unnecessary disturbance of the effervescent liquid inside,
resulting in a spray or spillage upon a subsequent opening of the
can.
[0016] EP 0 461 748 (ITW) and EP 0 621 203 (ITW) propose the
provision of tear-open tabs, which extend upwardly across the
chimes of straight-walled and conical cans, respectively, whereby
to simplify release. The tabs in the later patent have concave
lateral portions adjacent a stem of the tab "for stress relief".
Furthermore, both these documents involve the use of relatively
thick (greater than 400 .mu.m) carrier stocks which in placement
around cans are stretched beyond their elastic limit. These types
of carrier stock have not, however, been widely adopted.
SUMMARY OF THE INVENTION
[0017] The present invention seeks to overcome at least one problem
associated with the prior art. Notably the present invention to be
particularly described hereinafter seeks to provide a machine and
process for grouping and packaging containers such as cans and
bottles with a plastics carrier stock sheet comprising film
plastics whereby great stretching forces are not required to enable
attachment of several containers in a six-pack or similar smaller
or larger pack (so-called "unitising" of the containers).
[0018] This objective is achievable by use of an application roller
configured to urge an appropriate apertured carrier stock sheet
film progressively over the rims of successive containers
accumulated together for unitizing. The application roller
cooperates with the container upper edge (beading, chime or rim) to
locate and present an inner edge portion of an aperture of the
carrier stock sheet comprising plastics film to the upper edge and
progressively move that edge portion below the container upper edge
until the whole inner aperture edge becomes located below that
container upper edge.
[0019] Suitable apertured carrier stock sheet film in various
embodiments is subject of our co-pending patent applications GB 2
475 622 A and WO 2011 061 518 which are hereby incorporated by
reference.
[0020] The terms carrier, carrier stock, carrier sheet and
retaining sheet may be used interchangeably herein for ease in
describing different aspects of the invention, and refer to a
flexible carrier comprising a plastics film suitable for packaging
by a method to be more particularly described hereinbelow, notably
without requiring use of separating or stretching devices that
would in normal use for packaging containers, apply stretching
forces that would exceed the elastic deformation limit for the
plastics sheet material.
[0021] In particular it is notable that the application roller
which is adapted for urging the carrier stock upon the accumulated
containers according to this invention requires no widening jaws,
parting fingers or the like manipulators required in the prior art
for stretch-fitting of the carrier to the containers. Rather
according to the invention, in handling an apertured carrier or
retaining sheet for unitising a plurality of accumulated
containers, the roller and accumulated containers are juxtaposed
such that as the roller turns relative to the rim of a container,
an inner edge portion of an aperture of the apertured carrier sheet
engages under the rim at a first point of contact. Thereafter the
roller urges the remaining portions of the edge of the aperture to
ease over the rim so that progressively the edge portion above the
carrier sheet is urged under the rim until the complete aperture
edge is below the rim of the container.
[0022] In accordance with a first aspect of the invention, there is
provided machine for applying container carriers to containers by
means of a roller.
[0023] The configuration of the carrier stock, especially aperture
configuration is such that in conjunction with the rolling
application method in cooperation with an upper edge of the
container e.g. can, the initially flat carrier stock is
re-configured to a three dimensional configuration about the
can.
[0024] The carrier stock forming the container carrier to be
applied by the machine comprises a plastics film sheet material
having a number of apertures for holding a number of containers
together, the apertures arranged in series and extending in at
least a first direction, typically the machine direction, for
application as a continuous strip from a supply system such as a
reel of the aforesaid apertured plastics film. Suitably, the
apertures have a centre and edges wherein the edges defining the
apertures have a geometry which comprises a plurality of tabs
facing the centre, the tabs being separated by troughs, the troughs
comprising a root at a maximum point from the centre; wherein the
innermost edges of the tabs and the roots lie, respectively, on
first and second circumferences relative to the centre, the second
circumference being equal to or greater than a beading
circumference of a container; the configuration of the apertures
being such that, upon placement about a container, the edges of the
tabs engage with said beading of such a container as the plastics
film about the container is urged downwardly and the plastics film
elastically forms a three dimensional wave form structure about the
container.
[0025] The carrier film is preferably made from the group
consisting of polyolefinic plastics such as polyethylene and
polyethylene derivatives such as copolymers and addition polymers
or polymer blends, but other plastics materials with similar
mechanical properties may be used including recycled plastics. The
carrier film can be advantageously made from much thinner plastics
films, for example of up to about 350 .mu.m thickness plastics
film. A plastics film of at least about 50 to 75 .mu.m may be used
for some containers, and generally a plastics film of up to about
100 .mu.m would be suitable for many types of containers. The
carrier stock may be made entirely of plastics film for best
performance of the invention, but a laminate comprising said film
with another material which does not inhibit the flexibility to
allow the roller application of the carrier stock over containers
as described herein is not excluded. Likewise any coating,
labelling, marking, colour layer or applied foil which does not
interfere with the rolling application may be used.
[0026] The carrier plastics film apertures can be dimensioned to
fit around cylindrical walled cans. The carrier plastics film
apertures can be dimensioned to fit about reduced chime or necked
cans. The carrier plastics film apertures can be dimensioned to fit
about beading around the neck of a bottle. Thus the carrier films
are apertured to form a container engaging portion for each
container to be unitised or multi-packaged. The machine can accept
stock comprising a length of a single-rank or multi-rank apertured
film.
[0027] After such a plastics film is urged over the tops of the
containers, it is observed that the formerly flat plastics film
conforms partly to the neck or under chime part of the container
and otherwise forms a trough so that overall the flat plastics film
is converted in the intended use into an undulating surface
extending between containers unitised by the film.
[0028] The machine also comprises a conveyor system for the
transport of containers, which may be of a generally known type;
the conveyor being operable to feed the containers to an
accumulation position; and taking accumulated containers towards an
application station for the application of an apertured carrier or
retaining sheet e.g. of the aforesaid carrier stock. The machine
uses a roller for urging the apertured carrier or retaining sheet
on to the accumulated containers at the application station. The
roller receives apertured carrier or retaining sheet from a supply
system.
[0029] The roller for urging the apertured plastics film onto the
accumulated containers may have a modified surface configuration
for applying a certain amount of pressure upon the apertured
plastics film during or after urging of the apertured plastics film
upon the accumulated containers. This may have benefit in ensuring
that as the roller moves with respect to successive accumulated
containers each aperture is appropriately positioned with respect
to a rim of a container such that the edge of the aperture is
always urged below the rim of the respective container. In
particular the roller may have projections such as mutually spaced
pegs or ribs positioned to engage web between apertures of the
apertured carrier or retaining sheet of plastics film.
[0030] Conveniently, the conveyor and roller are arranged to
cooperate together, with the supply system, such that as the
conveyor moves the containers, the rims of the containers are
presented to the carrier stock of apertured plastics sheet, whereby
an inside tab edge of an aperture can abut against an underside
edge of a bead of a container. At the same time under the
continuing urging motion of the moving roller, the carrier stock of
apertured plastics film sheet is urged over the rims of the
conveyed accumulated containers. In particular the action of the
urging roller in applying the apertured plastics film is such that
the side edges of the aperture diverge elastically to surround the
sides of the container beading defining a rim of the container
until the inside edge of the aperture opposite the first engaged
side of the aperture is adjacent the rim. At that point the urging
action of the roller causes an inside edge of the said opposite
inside tab edge of the aperture to engage with an underside of the
rim, whereby to secure the apertured film with the can.
[0031] Conveniently, the conveyor moves the containers to an
accumulation position prior to being presented to the application
station. Conveniently, the conveyor moves the containers with
applied plastics film to a cutting apparatus, said cutting
apparatus being operable to enable appropriate pack sizes to be
produced, whereby separation of unitised container packs is
achievable.
[0032] Conveniently, there is provided a plurality of co-operating
sheeting supply mandrels whereby to provide a continuous supply of
sheeting to the roller, to enable a seamless connection of separate
sheets to provide effective continuous operation of the system.
[0033] In accordance with another aspect of the invention, there is
provided a method of unitizing containers, for example cans,
utilizing the machine and apertured plastics film further
comprising the steps: receiving a can; urging an inside edge of a
tab of an aperture toward an under-chime edge of the can; easing
adjacent side tabs of the aperture over the corresponding rim parts
of the can until the inside edge of the aperture opposite the first
engaged side of the aperture is adjacent the rim; and, causing an
inside edge of the last tab to engage with an underside of the rim,
whereby to secure the apertured film with the can.
[0034] The carrier stock suitable for use in the machine and method
of the invention is provided with a number of apertures for holding
a number of containers together, the carrier stock comprising a
plastics film material having a number of apertures arranged for
example as a series in at least a first direction, wherein the
apertures comprise a plurality of finger or tab elements, separated
by troughs, the apertures having a centre; wherein the innermost
edge or tip of the finger elements lie on a first circumference
relative to the centre and the bottom of the troughs lie on a
second circumference relative to the centre, the second
circumference being equal to or greater than the circumference of
the container; wherein the edges of the fingers are operably
engageable with a beading of a container as the troughs are urged
downwardly and outwardly; the troughs being operable to allow the
film to elastically deform upon placement and enable the film to
adopt a three dimensional structure. Whilst the present invention
requires at least three fingers or tabs, it has been found that a
four fingered (tabbed) aperture benefits in terms of packaging of
product by reason of the forces from the chime, through the finger,
allow upward movement of the film adjacent the troughs, whereby to
create a wave effect or undulating surface between adjacent
containers. The three dimensional structure adopted by the film is
analogous in effect to a vehicular monocoque structure; in that the
strength of the undulating shaped stock in contact with the
containers is greater than that of the otherwise flexible material
before it is urged into contact with the containers.
[0035] Applicants have determined that at the point where the tabs
or fingers meet with the underside of a beading of a container,
such as the chime of a beverage can, the material is deflected in a
downwards direction. Because the contact is discontinuous, this
creates a three dimensional wave in the material which acts against
the tabs or fingers and forces them to remain in contact with the
containers. At the corners of the sheet (in the case of a four pack
for example) opposite where the cut outs in the aperture are
situated, because there are no downward forces, only lateral ones
exerted by the effect of the fingers acting against the chimes, the
material is forced into an apex at its furthest point from the can
contributing to the wave effect. This combination of wave effect
and apex further prevents the fingers from moving away from the
underside of the chime and ensures the containers are held
securely.
[0036] The apertured material can be dimensioned to fit around
traditional cylindrical walled cans such as traditional baked-bean
can (say 307.times.512 US CMI). The apertured film can be
dimensioned to fit about the necked-in cans as are typically
presently produced in the beverage industry (2011) which in Europe
is one of the following types (all sizes approximate) 330 ml, 66 mm
O/115 mm height; 440 ml, 66 mm O/150 mm height; 500 ml (.about.16
fluid ounces US) 65 mm O/170 mm height.
[0037] Another 250 ml can size which has been introduced for
specialist beverages such as the so-called energy drinks is also
slightly necked and is about 52 mm O/135 mm height.
[0038] Due to these dimensional differences in containers to be
unitised at different times, the machine of the invention may be
equipped with adjustment means for changing the relative
positioning of the application roller with respect to the conveyed
and accumulated containers between packaging runs of differing
containers.
[0039] The apertured film can also be dimensioned to fit about the
ridge-necked bottles, wherein beading around the neck of a bottle
can act in a similar fashion to the chime or beading of a can.
[0040] The apertures can resemble a generally square-like
(quadra-arcuate) aperture, with the tabs comprising slightly
outwardly extending arcs. Other poly-arcuate apertures are
possible, the number of tabs, however being less than ten, for
containers as are commonly employed for beverages.
[0041] The carrier stock comprising plastics film used for the
present invention can comprise integrally joined band segments
defining can-receiving apertures in longitudinal rows and
transverse ranks. There may be a single longitudinal row. The band
segments include generally longitudinal outer segments with each
outer segment partly bounding the can receiving apertures in an
outer row. In application, the carrier stock or film can be
provided as a roll for use in a roll on method of applying the
product, conveniently in a multi-lane format of typically but not
exclusively 6 lanes wide. The sheet material is supplied on a roll
and feeds into the application machine in a near continuous action,
whereupon it is sub-divided within the machine into the required
pack sizes, e.g. 4 packs, 6 packs etc.
[0042] The method of rolling film on to the top of the container
uses the downward pressure of the roller as the containers pass
beneath it to gently elastically form the material through the
interaction of film and container in order to achieve the
aforementioned gripping action and three dimensional transformation
of the sheet material. Thus the roller in urging the film onto the
accumulated containers to be unitised also has a role in promoting
the performance of the film by urging a particular configuration to
be adopted.
[0043] In particular, the plastics film after application to a
number of containers defines a three dimensional shape as a direct
result of the various forces acting upon the material, whereby to
increase the inherent strength of the resultant product. As a
direct result of the increase in strength of the applied film (in
three-dimensions), a reduction in the grade and thickness of the
film material can be realised: costs can be reduced because less
raw material is required. Further by virtue of the machinery not
being required to exert tremendous forces to enable the material to
engage with containers, the specification of the packaging plant
can be reduced, again reducing costs. Overall significant energy
savings can be realised by virtue of the invention.
[0044] A still further advantage is that because the machinery is
less massive and can be applied without large mechanical jaws/hands
(as are presently used in the industry--which impede the function
of adjacently located mechanical jaws/hands), several packing
streams can be simply placed in side-by-side configuration--even
enabling 12-aperture rows to be manufactured.
[0045] Thus the present invention takes advantage of physical
properties of the apertured plastics film material whereby,
surprisingly, containers such as beverage cans can be retained by a
sheet of a thickness much reduced to the sheet widely employed
hitherto which has been placed over the rim of the container,
whereby a plurality of inner edges defined along an inner
circumference of the aperture abut an underside of the rim, in the
free state the inside circumference being less than the
circumference of the can, below the rim, the sheet material, by
virtue of a discontinuous circumferential contact about said rim,
whereby to conform in a three-dimensional form which offers
stability and strength to a container and film combination.
Specifically, the three-dimensional form provides a strength far
greater than that which would have been achievable with a standard
film. As a direct result of its increased strength, the material of
choice can be selected for price and availability rather than
quality per se.
[0046] The above and other advantages enable the objectives of the
invention to be achieved.
BRIEF DESCRIPTION OF THE FIGURES
[0047] Some preferred embodiments of the invention will now be
described, by way of example, with reference to the accompanying
drawings showing both prior art carrier stock and embodiments of
the invention, of which:
[0048] FIGS. 1a-c show a first example of known carrier stock;
[0049] FIGS. 2a, b show a second example of known carrier
stock;
[0050] FIGS. 3a-c show a third example of known carrier stock;
[0051] FIG. 4 shows a container carrier comprising strips of
material;
[0052] FIG. 5 shows another prior art container retaining
means;
[0053] FIGS. 6a, b show card and plastics laminate container
retaining means;
[0054] FIGS. 7a-e show examples of presently commonly used carrier
stock;
[0055] FIGS. 8a-c show a first embodiment of a film and the same in
use;
[0056] FIG. 9 shows a second embodiment;
[0057] FIG. 10 shows a third embodiment;
[0058] FIG. 11 shows a still further embodiment of the invention,
whilst FIG. 11a shows a variant thereof, and 11b-11d show the
variant of FIG. 11a in use;
[0059] FIGS. 12, 12a-12f detail steps in aspects of the application
process;
[0060] FIGS. 13a & b show packaging equipment in plan and side
views;
[0061] FIG. 14 shows a side view of an application drum in
accordance with another aspect of the invention; and,
[0062] FIGS. 15-20 show cans unitized with a further example of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0063] There will now be described, by way of example only, the
best mode currently contemplated by the inventor for carrying out
the present invention. In the following description, numerous
specific details are set out in order to provide a complete
understanding to the present invention. It will be apparent to
those skilled in the art, that the present invention may be put
into practice with variations of the specific.
Carrier Stock for Unitizing Containers
[0064] The present invention shall now be described with reference
to a first embodiment as shown in FIGS. 8a-c. FIGS. 8a and 8b show
first and second perspective views of an arrangement of five beer
cans retained by plastics film stock having six container
apertures.
[0065] The plastics film is shown in plan view in FIG. 8c. Each
aperture 80a is of a general square shape, operably arranged to
accept a circularly cylindrical part of a container therethrough,
with four fingers or tabs 81, 82, 83 & 84 extending from
indentations or troughs having a web element connecting adjacent
fingers or tabs. The troughs lie on a radius slightly greater than
the radius of the container about which the film is designed to
retain. The tips of the fingers or tabs, i.e. the portions that
will abut the rim or chime of the can, are conveniently slightly
curved inwardly. Indeed, in order to most closely fit about a
container, the arc corresponds to an arc of a circle of a radius
corresponding to a radius of the container that lies immediately
adjacent the rim or chime of the container, the shape taking into
account the fact that the film will adopt an undulating shape in
view of the resilience of the plastics film being utilised. It is
important to note that whilst the elastic properties of the film
are utilised, the elastic limit of the material is not
approached.
[0066] In use, carrier stock provided with a number of apertures
for holding a number of containers together, the stock comprising a
thin plastics film material having a number of apertures arranged
in at least a first direction. The apertures comprise a plurality
of tab or finger elements, separated by troughs, the apertures
having a centre. The tip of the finger elements lie on a first
circumference relative to the centre whilst the bottom of the
troughs (that part of the troughs most distant from the centre) lie
on a second circumference relative to the centre, the second
circumference being equal to or greater than the circumference of
the container. In use the tips of the fingers engage with a beading
of a container whilst the troughs, as a direct result--since they
are part of the same film--are urged downwardly and outwardly. In
so doing the troughs urge the film to elastically form upon
placement and enable the film to adopt a three dimensional
structure. Whilst the number of tabs or fingers can vary from three
upwards, it has been found that a four fingered aperture (or
multiple finger equivalents operable to achieve the same effect)
benefits in terms of packaging of product by reason of the forces
from the chime, through the finger, allow upward movement of film
adjacent the troughs, whereby to create a wave effect. The three
dimensional structure adopted by the film is in many ways analogous
to the types of structures in vehicular manufacturing i.e. the
structure is a monocoque structure where the overall strength of
the finished film is greater than that of the inherently flexible
material.
[0067] Referring in particular to FIG. 8c, film 80 is provided with
apertures 81, the apertures being defined by fingers 82-85. One
aperture 81 will now be discussed; the distance between the centres
of oppositely facing fingers is approximately 90% of the diameter
of the portion of the container about which the aperture will close
upon, whilst the distance between opposite troughs corresponds to
110% of said diameter. As can be seen, with further reference to
FIGS. 8a and 8b, the fingers 82-85 abut the lower part of the chime
or rim of the can and the film closely follows the necked-in
portion of the container. Rather than utilising the elasticity of
the material to enable containers to be retained, the film in
accordance with the invention when applied by rolling as described
herein adopts a three dimensional geometrical form that enables the
shape of the film to thereby provide a relatively rigid
arrangement. In actual fact, rather than utilise high quality
virgin plastics film of a preferred thickness in the range of
400-500 .mu.m, the present invention can utilise recycled plastics
film of a thickness of about 350 .mu.m or even much less e.g. about
100 .mu.m or less depending upon the containers to be unitised,
with the aim to use as little weight as possible by use of thinner
materials. It is to be realised that whilst the weight of a single
apertured film for a six-pack is of the order of a couple of
grammes, globally, several thousands of tons of plastics are
employed in the manufacture of container unitising film. A
reduction in the amount of plastics by 25% or more will provide a
significant reduction in operating costs for any canning plant.
Additionally, it is known in the art (for example EP1038791), that
any buckling of a transverse web is to be minimised because of
customer perception; a smooth transverse web is believed to be more
aesthetically pleasing.
[0068] As will be appreciated, prior systems for linking containers
more closely approach the elastic deformation limit of the plastics
material. Indeed, in the apparatus as shown in U.S. Pat. No.
4,250,682 a machine is shown which engages a carrier strip and
assembles the carrier strip with a plurality of articles moving in
close relation thereto. The apparatus in U.S. Pat. No. 4,250,682
has a rotary drum with carrier stretching members for engaging,
stretching and positioning the carrier strip over the tops of the
articles moving there-under such that the carrier material is
retained under the chime of the article. Similarly, in another
teaching (EPO456357) it is stated that a carrier strip engaging
assembly is used to elastically deform the engaged carrier strip
for assembly with articles.
[0069] Since recycled materials are more likely to have inclusions
and other faults, which can compromise the strength of material
that is stretched towards an elastic limit, the industry has
previously not been able to accept such materials, increasing the
financial burden in the packaging industry. Not only does the
present invention provide a solution which uses less raw material
and is according more "environmentally friendly" than prior
solutions, the raw material for the present invention can indeed
comprise recycled material or at least have a significant recycled
material content.
Packaging (Unitising) Method
[0070] The procedure of application of the apertured film in
accordance with the present invention can be conveniently formed by
a number of methods. A presently preferred method will be described
with reference to FIG. 8c, which, for convenience shall be assumed
to be receiving a can, not shown, from the right; the inside edge
of finger 84 of the aperture is urged toward the under-chime (upper
rim) of a can; the adjacent side fingers 81, 83 of the aperture are
then eased over the corresponding rim parts of the can until the
inside edge of the aperture opposite the first engaged side of the
aperture is adjacent the rim, whereupon continuing pressure enables
the inside edge of the last aperture finger 82 to engage with an
underside of the rim, thereby enabling the apertured film to be
simply, safely and securely engaged therewith. It will be
appreciated that since significant forces would not be required to
enable the apertures to be placed over containers, then the
machinery need not be so massive and that three or more containers
may be easily be retained by a film in accordance with the
invention; previous systems cannot reliably utilize more than two
containers in a process such as a fast moving production line.
[0071] Whilst the first example is a square aperture, it will be
appreciated that a generally three fingered aperture may be
provided, comprising a generally equilateral triangular
configuration, and would provide a minimally fingered design with a
security of retention. It will be appreciated that many polygonal
form can be configured which operate in accordance with the
inventions, although, a regular four-sided aperture is likely to be
more readily generally accepted. Containers of other cylindrical
shapes can be retained; it may be appropriate to have five, six or
more fingers or tabs per aperture. Ten has been found to be a
convenient number for large domestic containers.
[0072] Referring now to FIG. 9, a portion of film 90, with six
apertures abreast, is shown, the apertures 91 being of a second
regular quadrilateral shape. Further apertures or slits 92,
together with circular apertures 93 are sized and positioned to
assist in the maintenance of the monocoque film shape, once
containers have been retained by the film. The circular opening 93
may be formed of difference shapes or may be replaced by a number
of smaller aperture, conveniently closely spaced together. In this
film the shape and position of the apertures are such that the
troughs between the fingers correspond with the corners of the
curved sides, the distance between opposite troughs being
approximately 110% the diameter of the container at the rim.
[0073] FIG. 10 shows a further portion of film 100, which has
generally square apertures 101, which have fingers 102-105
separated by small troughs 106-109. The troughs are move pronounced
with respect to the troughs of FIGS. 9 and 11, but may be of other
shapes with regard to a requirement not to induce tears in the
film. Again the distance between opposite troughs is approximately
110% the diameter of the container at the rim. FIG. 11 shows a
still further embodiment, wherein each side of a generally square
aperture comprises distinct arc sections 111-114; the troughs can
be considered to exist at the centre of adjacent arcs 115-118. FIG.
11a shows a variant of the arcuate quadrilateral design wherein a
substantially square aperture acts with tab elements having an
inwardly facing arcuate tab. FIGS. 11 b-11d show the variant of
FIG. 11a in use.
[0074] A significant advantage of the present invention is that the
mechanical properties of the material are only required to be
strong enough to hold the cans, and not stand up to the rigours and
high stretch of the standard application processes encountered in
the prior art. Not only does this have significant advantages in
the manufacturing processes (reduced operating forces incur less
wear for application machines and thus further reduce operating
costs), and also enables the use of cheaper plastics to be
employed. Indeed, recycled plastics such as low grade Post Consumer
Waste (e.g. low density polyethylene--LDPE) can be employed which
also satisfies the perennial demands of market requirements in that
the basic consumable materials are cheaper. As discussed above, in
view of the materials not needing to be stretched to particular
limits, the thickness of the basic product can also be reduced i.e.
the thickness can be 300 .mu.m (or less): the issue of the presence
of inclusions or not is of no consequence. A preferred thickness
for such stock for prior systems in an unstressed condition has
been in a range from approximately 16 mils (400 .mu.m) to
approximately 17.5 mils (445 .mu.m). The present invention allows
the use of raw material that can be purchased at far more
favourable rates than specified high quality material.
[0075] A preferred method of application utilises a simple roll on
application method as shall be disclosed in detail hereinafter; a
simple machine can be utilised in manufacturing industry; since
great stretching forces are not applied, lever arm and/or hydraulic
operations can be minimised and the strength of the machine need
not be great, as a direct result compared to systems which stretch
plastics towards and beyond their elastic limits. The use of
simpler and cheaper machines will also enable the systems to be
operated by smaller manufacturing concerns and thereby increase
markets.
[0076] FIGS. 12a-12f show a superposition of the edges of an
un-stretched aperture upon a beading 126 of a container 122. FIG.
12a shows how, in a first application step associated with
retaining a number of containers with a stock of apertured plastics
sheeting in accordance with the present invention. An inside tab
edge 121 of the aperture abuts against an underside edge of a bead
126 of the container. FIG. 12b shows how, in relation to the
apertured plastics sheet stock 100 an application roller will
rotate with respect to a container passing underneath in a
direction perpendicular to the roller axis. The roller is not
shown, although the stock is shown having an arcuate profile and
will be discussed in greater detail with respect to machinery
below.
[0077] As the roller continues to move, with reference to FIGS. 12c
& 12d the side edges 123 & 125 of the aperture diverge
elastically to surround the sides of the container beading 126. It
will be appreciated that this figure is part cross-section in the
plane of the beading 126 and part side-perspective view of the can
122. The application forces AF, acting from a centre of the
application roller, are relatively gentle--no forces which stretch
the plastics sheet material beyond its elastic limit are present.
FIGS. 12e and 12f show corresponding plan and side view of the
application process as the edge 127 is received by the rim of the
container 126--as shown, the application roller is shown as the
container passes below the axis of the roller.
[0078] As discussed above, in view of the reduced forces necessary
to assemble containers, system power requirements would be reduced
and energy consumption would be reduced. For example, by having the
system applying film to containers in 6-12 rank widths, then
packing stations can be made more compact and simplify distribution
since larger widths of format negate a need to divert packs after
application ready for tray packing process. A still further
advantage in having a wider operating width is that the overall
velocity of machinery can be reduced. Compared to a 2-rank packing
system, the operating speed is one third to one sixth the speed of
such 2-rank packing systems. This will have concomitant advantages
in the lifetime, reliability (down-times are expensive) and cost in
the conveyor, the motors and supporting equipment. Equally the
demands on material would be reduced, also permitting the use of
lower grade material.
Packaging Plant Including Unitising Machine
[0079] With reference to FIGS. 13a & 13b, there are shown plan
and side views of an otherwise standard conveyor system 130 for the
transport of containers in the form of soft-drinks cans 139 or
similar. In particular, with reference to FIG. 13b, the cans 139
are fed along a conveyor to an accumulation position 134
(proceeding in a direction indicated by arrow 138). In the
accumulation position, the containers are brought towards each
other in close proximity in preparation for the application of the
apertured retaining sheet, performed by roller 132 which receives
sheet 110 from sheeting supply system 133. Cutting apparatus
controlled between the units labelled 136 enable appropriate pack
sizes to be produced. With reference to FIG. 13b, sheeting supply
mandrel 135 can co-operate with another mandrel (not shown) to
provide a continuous supply of sheeting to the roller 132. As is
known, seamless connection of separate sheets can be performed to
provide effective continuous operation, or at least almost
continuous operation of the system.
[0080] FIG. 14 shows, respectively side and detail view of the
application drum and production line conveyor arrangement. FIGS.
16-20 show cans unitised with a further example of a carrier stock
in accordance with the invention.
[0081] The application drum which urges the carrier stock upon the
containers to be unitised may have a plurality of peg projections
configured to interact with a carrier stock sheet to facilitate
appropriate downward pressure upon the carrier stock and assist in
elastically forming a three dimensional structure of the carrier
stock about the upper part of the containers.
[0082] It will be appreciated that, since the containers can be
arranged in 6+ wide lines, then different lines may be packaged
differently using known techniques, adding variability to the
production line process. Additionally, it would be possible, with
appropriate channelling, to have cross over with other products
(brands) whereby a perceived need for other machines/systems is not
necessary. The carrier stock is formed, for example by die-cutting,
from a single sheet of resilient polymeric material, such as low
density polyethylene. Known carrier stock has been formed of high
quality plastics sheet, such as low density polyethylene.
* * * * *