Title of Invention

SEMI-RIGID COLLAPSIBLE CONTAINER

Abstract A semi-rigid collapsible container (10) has a side-wall with an upper portion (5), a central portion (6), a lower portion (7) and a base (8). The central protion (6) includes a vacuum panel portion having a control portion (2) and an initiator portion (1). The control portion (2) is inclined more steeply in a vertical direction, i.e. has a more acute angle relative to the longitudinal axis of the container (10), than the initiator portion (1). On low vacuum force being present within the container panel following the cooling of a hot liquid in the container (10), the initiator portion (1) will flex inwardly to cause the control protion (2) to invert and flex further inwardly into the container (10) and the central portion (6) to collapse. In the collapsed state upper and lower portions of the central portion (6) may be in substantial contact so as to contain the top-loading capacity of the container (10). Raised ribs (3) made an aditional support for the container in its collapsed state. In another embodiment the telescoping of the container back to its original position occurs when the vacuum force is released following removal of the container cap.
Full Text 2

Background To Invention
This invention relates to polyester containers, particularly semirigid collapsible containers capable of being filled with hot liquid, and more particularly to an improved construction for initiating collapse in such containers.
'Hot-Fill' applications impose significant mechanical stress on a container structure. The thin side-wall construction of a conventional container deforms or colfapses as the internal container pressure falls following capping because of the subsequent cooling of the liquid contents. Various methods have been devised to sustain such internal pressure change while maintaining a controlled configuration.
Generally, the polyester must be heat-treated to induce molecular changes resulting in a container that exhibits thermal stability. In addition, the structure of the container must be designed to allow sections, or panels, to 'flex' inwardly to vent the internal vacuum and so prevent excess force being applied to the container structure. The amount of 'flex' available in prior art, vertically disposed flex panels is limited, however, and as the limit is reached the force is transferred to the side-wall, and in particular the areas between the panels, of the container causing them to fail under any increased load.
Additionally, vacuum force is required in order to flex the panels inwardly to accomplish pressure stabilisation. Therefore, even if the panels are designed to be extremely flexible and efficient, force will still be exerted on the container structure to some degree. The more force that is exerted results in a demand for increased container wall-thickness, which in turn results in increased container cost.

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The principal mode of failure in all prior art known to the
applicant is non-recoverable buckling, due to weakness in the structural geometry of the container, when the weight of the container is lowered for commercial advantage. Many attempts to solve this problem have been directed to adding reinforcements to the container side-wall or to the panels themselves, and also to providing panel shapes that flex at lower thresholds of vacuum pressure.
To date, only containers utilising vertically oriented vacuum flex
panels have been commercially presented and successful.
In Indian patent 177589 dated entitled "Collapsible
Container delicates a semi-rigid collapsible containe is in which controlled collapsing is achieved by a plurality of arced panels which are able to resist expansion from internal pressure, but are able to expand transversely to enable collapsing of a folding portion under a longitudinal collapsing force. Much prior art in collapsible containers was disclosed, most of which provided for a bellows-like, or accordion-like vertical collapsing of the container.
Such accordion-like structures are inherently unsuitable for hot-fill applications, as they exhibit difficulty in maintaining container stability under compressive load. Such containers flex their sidewalls away from the central longitudinal axis of the container. Further, labels cannot be properly applied over such sections due to the vertical movement that takes place. This results in severe label distortion. For successful label application, the surface underneath must be structurally stable, as found in much prior art cold-fill container sidewalls whereby corrugations are provided for increased shape retention of the container under compressive load. Such compressive load could be supplied by either

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increased top-load or increased vacuum pressure generated within a hot-fill container for example.
Oblects of the Invention
It is an object of the invention to provide a semi-rigid collapsible, containerwhlch is able to more efficiently compensate for vacuum pressure in the container and to overcome or at least amellate problems with prior art proposals to date and/or to at least provide the public with a useful choice.
Summary Of The Invention
According to one aspect of this invention there is provided a semirigid collapsible container having a longitudinal axis and which has at least one substantially vertically folding vacuum panel portion to compensate for vacuum pressure change and wherein said vertically folding vacuum panel portion includes an initiator portion and a control portion, said initiator portion providing for vertical folding along said longitudinal axis before said control portion.
Preferably the vacuum panel is adapted to fold Inwardly under an externally applied mechanical force in order to completely remove vacuum pressure generated by the cooling of the liquid contents, and to prevent expansion from the collapsed state when the container is uncapped.
According to a further aspect of this invention there is provided a semi-rigid collapsible container, having a longitudinal axis and which has a substantially vertically folding vacuum panel portion including an Initiator portion and a control portion, said initiator portion providing for vertical folding along said longitudinal axis before said control portion and which enables expansion from the collapsed state.
Preferably the vacuum panel is adapted to fold Inwardly under a vacuum force below a predetermined level and to enable expansion from

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the collapsed state when the container is uncapped and vacuum released.
Further aspects of this invention, which should be considered in all its novel aspects, will become apparent from the following description.

Brief Description of the accompanying Drawings
Figure 1: shows diagrammatically a semi-rigid collapsible
container according to one possible embodiment of the invention in its pre-collapsed condition;
Figure 2: shows the container of Figure 1 in its collapsed condition;
Figure 3: very diagrammatically shows a cross-sectional
view of the container of Figure 2 along the arrows A-A;
Figure 4: shows the container of Figure 1 along arrows A-A;
Figure 5: shows a container according to a further possible embodiment of the invention;
Figure 6: shows the container of Figure 5 after collapse;
Figure 7: shows a cross-sectional view of the container of Figure 6 along arrows B-B; and
Figure 8: shows a cross-sectional view of the containerof Figure 5 along arrows B-B.

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Description Of Preferred Embodiments
The present invention relates to collapsible semi-rigid containers having a side-wall with at least one substantially vertically folding vacuum panel section which compensates for vacuum pressure within the container.
Preferably in one embodiment the flexing may be inwardly, from an applied mechanical force. By calculating the amount of volume reduction that is required to negate the effects of vacuum pressure that would normally occur when the hot liquid cools inside the container, a vertically folding portion can be configured to allow completely for this volume reduction within itself. By mechanically folding the portion down after hot filling, there is complete removal of any vacuum force generated inside the container during liquid cooling. As there is no resulting vacuum pressure remaining inside the cooled container, there is little or no force generated against the sidewall, causing less stress to be applied to the container sidewalls than in prior art.
Further, by configuring the control portion to have a steep angle, expansion from the collapsed state when the container is uncapped is also prevented. A large amount of force, equivalent to that mechanically applied initially, would be required to revert the control portion to its previous position. This ready evacuation of volume with negation of internal vacuum force is quite unlike prior art vacuum panel container performance.
¦ The present invention may be a container of any required shape or size and made from any suitable material and by any suitable technique. However, aplastics container blow moulded from polyethylene tetraphalate (PET) may be particularly preferred.

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One possible-design of semi-rigid container is shown in Figures 1 to 4 of the accompanying drawings. The container referenced generally by arrow C is shown with an open neck portion 4 leading to a bulbous upper portion 5, a central portion 6, a lower portion 7 and a base 8.
The central portion 6 provides a vacuum panel portion that will fold substantially vertically to compensate for vacuum pressure in the container 10 following cooling of the hot liquid.
The vacuum panel portion has an initiator portion 1 capable of flexing inwardly under low vacuum force and causes a more vertically steeply inclined (a more acute angle relative to the longitudinal axis of the container 10), controi portion 2 to invert and flex further inwardly into the container 10.
The provision of an initiator portion 1 allows for a steep, relative to the longitudinal, angle to be utifised in the control portion 2. Without an initiator portion 1, the level of force needed to invert the control portion 2 may be undesirably raised. This enables strong resistance to expansion from the collapsed state of the bottte 1. Further, without an initiator portion to initiate inversion of the control portion, the control portion may be subject to undesirable buckling under compressive vertical load. Such buckling could result in failure of the control portion to fold into itself satisfactorily. Far greater evacuation of volume is therefore generated from a single panel section than from prior art vacuum flex panels. Vacuum pressure is subsequently reduced to a greater degree than prior art proposals causing less stress to be applied to the container side walls.
Moreover, when the vacuum pressure is adjusted following application of a cap to the neck portion 4 of the container 10 and subsequent cooling of the container contents, it is possible for the

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collapsing section to cause ambient or even raised pressure conditions inside the container 10.
This increased venting of vacuum pressure provides advantageously for less force to be transmitted to the side walls of the container 10. This allows for less material to be necessarily utilised in the construction of the container 10 making production cheaper. This also allows for less failure under load of the container 10, and there is much less requirement for panel area to be necessarily deployed in a design of a hot fill container, such as container 10. Consequently, this allows for the provision of other more aesthetically pleasing designs to be employed in container design for hot fill applications. For example, shapes could be employed that would otherwise suffer detrimentally from the effects of vacuum pressure. Additionally, it would be possible to fully support the label application area, instead of having a 'crinkle' area underneath which is present with the voids provided by prior art containers utilising vertically oriented vacuum flex panels.
In a particular embodiment of the present invention, support structures 3, such as raised radial ribs as shown, may be provided around the central portion 6 so that, as seen particularly in Figures 2 and 3, with the initiator portion 1 and the control portion 2 collapsed, they may ultimately rest in close association and substantial contact with the support structures 3 in order to maintain or contribute to top-load capabilities, as shown at 1b and 2b and 3b in Figure 3.
In a further embodiment a telescopic vacuum panel is capable of flexing inwardly under low vacuum force, and enables expansion from the collapsed state when the container is uncapped and the vacuum released.

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Preferably in one embodiment the initiator portion is configured to provide for inward flexing under low vacuum force. The control portion is configured to allow for vacuum compensation appropriate to the container size, such that vacuum force is maintained, but kept relatively low, and only sufficient to draw the vertically folding vacuum panel section down until further vacuum compensation is not required. This will enable expansion from the collapsed state when the container is uncapped and vacuum released. Without the low vacuum force pulling the vertically folding vacuum panel section down, it will reverse in direction immediately due to the forces generated by the memory in the plastic material. This provides for a 'tamper-evident' feature for the consumer, allowing as it does for visual confirmation that the product has not been opened previously.
Additionally, the verticafly folding vacuum panel section may employ two opposing initiator portions and two opposing control portions. Reducing the degree of flex required from each control portion subsequently reduces vacuum pressure to a greater degree. This is achieved through employing two control portions, each required to vent only half the amount of vacuum force normally required of a single portion. Vacuum pressure is subsequently reduced more than from prior art vacuum flex panels, which are not easily configured to provide such a volume of ready inward movement. Again, less stress is applied to the container side-walls.
Moreover, when the vacuum pressure is adjusted following application of the cap to the container, and subsequent cooling of the contents, top load capacity for the container is maintained through side-wall contact occurring through complete vertical collapse of the vacuum panel section.

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Still, further, the telescopic panel provides good annular strengthening to the package when opened.
Referring now to Figures 5 to 8 of the drawings, preferably in this embodiment there are two opposing initiator portions, upper initiator portion 103 and lower initiator portion 105, and two opposing control portions provided, upper control portion 104 and lower control portion 106. When the vacuum pressure is adjusted following application of a cap (not shown) to the container 100, and subsequent cooling of the contents, top load capacity for the container 100 is maintained through upper side-wall 200 and lower side-wall 300 contact occurring through complete or substantially complete vertical collapse of the vacuum panel section, see Figures 6 and 7.
This increased venting of vacuum pressure provides advantageously for less force to be transmitted to the side-walls 100 and 300 of the container 100. This allows for less material to be necessarily utilised in the container construction, making production cheaper.
This allows for less failure under load of the container 100 and there is no longer any requirement for a vertically oriented panel area to be necessarily deployed in the design of hot-fill containers. Consequently, this allows for the provision of other more aesthetically pleasing designs to be employed in container design for hot-fill applications. Further, this allows for a label to be fully supported by total contact with a side-wall which allows for more rapid and accurate label applications.
Additionally, when the cap is released from a vacuum filled container that employs two opposing collapsing sections, each control portion 104, 106 as seen in Figure 7, is held in a flexed position and will

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immediately telescope back to its original position, as seen in Figure 8. There is immediately a larger headspace in the container which not only aids in pouring of the contents, but prevents 'blow-back' of the contents, or spillage upon first opening.
Further embodiments of the present invention may allow for a telescopic vacuum panel to be depressed prior to, or during, the filling process for certain contents that will subsequently develop internal pressure before cooling and requiring vacuum compensation. In this embodiment the panel is compressed vertically, thereby providing for vertical telescopic enlargement during the internal pressure phase to prevent forces being transferred to the side-walls, and then the panel is able to collapse again telescopically to allow for subsequent vacuum compensation.
Although two panel portions 101 and 102 are shown in the drawings it is envisaged that less than two may be utilised.
Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.
Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims.

1. A semi-rigid collapsible container having a longitudinal axis and
which has at least one substantially vertically folding vacuum panel
portion to compensate for vacuum pressure change within the '
container, and wherein said vertically folding vacuum panel portion
includes an Initiator portion and a control portion, said initiator portion
providing for vertical folding along said longitudinal axis before said
control portion.
2. A semi-rigid collapsible container as claimed in claim 1 wherein said
control section resists being expanded from the collapsed 6tate.
3. A semi-rigid collapsible container as claimed in claim 1 wherein the
vacuum panel is adapted to flex inwardly under a vacuum force
below a predetermined level and enables expansion from the
collapsed state when the container is uncapped and vacuum
released.
4. A semi-rigid collapsible container as claimed In claim 2 wherein said
vacuum pane! portion is provided between an upper portion and a
lower portion of a side wall of the container, the initiator portion
Intermediate between a lower end of said upper portion and said
control portion.
5. A semi-rigid collapsible container as claimed in any one of the
preceding claims wherein said control portion has a more acute
angle than the initiator portion relative to the longitudinal axis of the ..
container and wherein the initiator portion causes said control portion
to invert and flex further Inwardly Into the container.
6. A semi-rigid collapsible container as claimed in claim 5 wherein, In
the collapsed state, upper and lower portions of said vacuum panel

portion are adapted to be in substantial contact.
7. A semi-rigid collapsible container as claimed in claim 6 wherein said
vacuum panel portion includes a plurality of spaced apart supporting
- ribs adapted to be in substantial contact with said control portion when the vacuum panel portion is In Its collapsed state to contribute to the maintenance of top-load capabilities of the container.
8. A semi-rigld collapsible container having a longitudinal axis and a
wall of which with an upper portion and a lower portion and a
substantially central portion having a substantially vertically folding
vacuum panel portion, said vacuum panel portion Including an
initiator portion and a control portion, said control portion being
Inclined along said longitudinal axis of the container at a lesser angle
than that of the initiator portion, the arrangement being such that the
initiator portion will react to a vacuum force within the container to
cause said control portion to Invert and flex further inwardly into the
container wherein the vacuum panel portion is adapted to revert to
its original position on the removal of a cap from the container
releasing the vacuum pressure.
9. A semi-rigid collapsible container as claimed in claim 1 wherein said
wall has said vacuum panel portion provided between an upper
portion and a lower portion, the control portion intermediate between
a lower end of said upper portion and said initiator portion.
10. A semi-rigid collapsible container as claimed in claim 1 wherein a
wall has said vacuum panel portion provided between an upper
portion and a lower portion wherein in the collapsed state said upper
and lower portions of said container are adapted to be in substantial
contact.
11. A semi-rigid collapsible container as claimed in claim 1 wherein said
vertically folding vacuum panel portion Includes two said initiator

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portions and two said control portions, said initiator portions providing for vertical folding before said control portions.
12. A semi-rigid collapsible container as claimed in claim 11 wherein
said control portions are held In a flexed position under vacuum
pressure, such that upon release of said vacuum pressure, said control portions and said initiator portions revert back to their original position.
13. A semi-rigid collapsible container as claimed in claim 1 wherein said
control portion Is held in a flexed position under vacuum pressure,
such that upon release of said vacuum pressure, said control portion.
and said initiator portion revert back to their original position.
14. A semi-rigid container substantially as herein described with
reference to Figures 1 to 4 or Figures 6 to 8 of the accompanying
drawings.
A semi-rigid collapsible container (10) has a side-wall with an upper portion (5), a central portion (6), a lower portion (7) and a base (8). The central protion (6) includes a vacuum panel portion having a control portion (2) and an initiator portion (1). The control portion (2) is inclined more steeply in a vertical direction, i.e. has a more acute angle relative to the longitudinal axis of the container (10), than the initiator portion (1). On low vacuum force being present within the container panel following the cooling of a hot liquid in the container (10), the initiator portion (1) will flex inwardly to cause the control protion (2) to invert and flex further inwardly into the container (10) and the central portion (6) to collapse. In the collapsed state upper and lower portions of the central portion (6) may be in substantial contact so as to contain the top-loading capacity of the container (10). Raised ribs (3) made an aditional support for the container in its collapsed state. In another embodiment the telescoping of the container back to its original position occurs when the vacuum force is released following removal of the container cap.


Documents:

00243-kolnp-2003 abstract.pdf

00243-kolnp-2003 assignment.pdf

00243-kolnp-2003 claims.pdf

00243-kolnp-2003 correspondence.pdf

00243-kolnp-2003 description(complete).pdf

00243-kolnp-2003 drawings.pdf

00243-kolnp-2003 form-1.pdf

00243-kolnp-2003 form-18.pdf

00243-kolnp-2003 form-2.pdf

00243-kolnp-2003 form-3.pdf

00243-kolnp-2003 form-5.pdf

00243-kolnp-2003 g.p.a.pdf

00243-kolnp-2003 latters patent.pdf

00243-kolnp-2003 priority document.pdf

00243-kolnp-2003 reply f.e.r.pdf

243-KOLNP-2003-FORM-27.pdf

243-kolnp-2003-granted-abstract.pdf

243-kolnp-2003-granted-claims.pdf

243-kolnp-2003-granted-description (complete).pdf

243-kolnp-2003-granted-drawings.pdf

243-kolnp-2003-granted-form 2.pdf

243-kolnp-2003-granted-specification.pdf

243-kolnp-2003-priority document.pdf

243-kolnp-2003-translated copy of priority document.pdf


Patent Number 212266
Indian Patent Application Number 243/KOLNP/2003
PG Journal Number 48/2007
Publication Date 30-Nov-2007
Grant Date 28-Nov-2007
Date of Filing 26-Feb-2003
Name of Patentee CO2 PAC LIMITED
Applicant Address 88-90 BALMORAL ROAD, MT EDEN, AUCKLAND
Inventors:
# Inventor's Name Inventor's Address
1 MELROSE DAVID MURRAY 90 BALMORAL ROAD, MT. EDEN, AUCKLAND
PCT International Classification Number B 65 D 1/02, 1/40
PCT International Application Number PCT/NZ01/00176
PCT International Filing date 2001-08-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 512423 2001-06-15 New Zealand
2 506684 2000-08-31 New Zealand