WO2016173866A1

WO2016173866A1 - Packaging method including inversion and labeling steps on a container

Info

Publication number: WO2016173866A1
Application number: PCT/EP2016/058437
Authority: WO
Inventors: Franck HANCARD
Original assignee: Sidel Participations
Priority date: 2015-04-29
Filing date: 2016-04-15
Publication date: 2016-11-03
Also published as: EP3088351A1

Abstract

Packaging method including the following steps: a step of providing an empty container (2) comprising a sidewall (6), an open neck (3) and a base (8) including a standing ring (9) and a central invertible diaphragm (10) articulated with respect to the standing ring (9), said diaphragm (10) being in an outwardly- inclined position; a filling step of pouring a product (17) within the container (2) through the neck (3); a capping step of sealingly closing the filled container (2) by means of a cap (19) mounted onto the neck (3); an inversion step of displacing the diaphragm (10) from to an inwardly-inclined position; a labeling step of attaching a label (46) onto the container sidewall (6), initiated before completion of the inversion step and conducted at least partly during the inversion step.

Description

Packaging method including inversion and labeling steps on a container

FIELD OF THE INVENTION The invention generally relates to the packaging of containers, wherein containers are filled, capped and labeled. More specifically, the invention relates to the packaging of containers including a base provided with a standing ring and a central invertible diaphragm articulated with respect to the standing ring between an outwardly-inclined position and an inwardly-inclined position.

Such containers are suitable for the packaging of hot pourable products (typically a liquid), the term "hot" meaning that the temperature of the product is higher than the glass transition temperature of the material, in which the container is made. Typically, hot filling of PET containers (the glass transition temperature of which is of about 80°C) is conducted with products at a temperature comprised between about 85°C and about 100°C, typically at 88°C.

BACKGROUND OF THE INVENTION

U.S. Patent No. 8,671,653 (assigned to Graham Packaging Company) discloses a system for processing a container to be filled with a hot product, wherein the container has a vacuum panel at a bottom end-wall of the container. The vacuum panel is movable between a downwardly inclined position to an upwardly inclined position. Before its filling, the container is positioned in a base cup structure; then it is hot filled with the vacuum panel in the downwardly inclined position. After the container and the product it contains have been cooled, the vacuum panel is moved to its upwardly inclined position, and the container is then sent to a conveying line to be fed to a labeling operation.

This process has several drawbacks.

Firstly, it requires one stand-alone machine for each step.

Secondly, the final packaging has defects.

More precisely, by the time the container reaches the labeling operation, it has lost some of its rigidity, due to a partial sinking of the vacuum panel under the hydrostatic pressure of the content. As a result, the label is affixed to a flexible surface, which later becomes even more flexible as the vacuum panel further sinks. The label therefore creases and becomes loose around the container, which is harmful to the container aesthetics and increases the risk of the client (or even the retailer) tearing apart the label during handling of the container. Reducing the thickness of the label amplifies this phenomenon.

SUMMARY OF THE INVENTION

It is therefore one object of the invention to alleviate those drawbacks and provide a packaging method through which the label is more firmly affixed to the container.

It is another object of the invention to provide a packaging method, which authorizes the use of thinner labels.

The invention provides a packaging method including the following steps:

a step of providing an empty container comprising a sidewall, an open neck and a base including a standing ring and a central invertible diaphragm articulated with respect to the standing ring, said diaphragm being in an outwardly-inclined position;

a filling step of pouring a product within the container through the neck;

a capping step of sealingly closing the filled container by means of a cap mounted onto the neck;

an inversion step of displacing the diaphragm from its outwardly- inclined position to an inwardly-inclined position;

a labeling step of attaching a label onto the container sidewall, initiated before completion of the inversion step and conducted at least partly during the inversion step.

The labeling step may be initiated before initiation of the inversion step.

The labeling step may be achieved before completion of the inversion step, and possibly even before initiation of the inversion step.

The inversion step is conducted by means of a pusher.

In possible embodiments, the pusher is hydraulically or pneumatically actuated; the pusher may also be electrically actuated.

The above and other objects and advantages of the invention will become apparent from the detailed description of preferred embodiments, considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is a perspective view partly showing a container handling and packaging machine.

FIG.2 and FIG.3 are similar cut views showing successive steps of a packaging method conducted in the machine of FIG.1.

FIG.4 is a diagram including, from top to bottom, a curve illustrating an inversion phase of the container base diaphragm, and four different chronograms illustrating five example embodiments of the labeling phase, in time correspondence with the top curve.

DETAILED DESCRIPTION Partly shown on FIG.1 is a container handling and packaging machine 1.

Each container 2 is made by blow molding or stretch blow molding from a preform made of plastic such as PET. In a preferred though not exclusive embodiment, the container 2 is a hot-fillable container, i.e. it has undergone, during the blow molding process, a heat setting phase in order to increase the resistance of the container 2 to thermal stresses undergone during a filling step with a hot product, "hot" meaning that the temperature of the product is higher than the glass transition temperature of the material. In the case of PET, which has a glass transition temperature of about 80°C, the hot pourable product has for example a filling temperature in a range of about 85-95°C. Examples of hot pourable liquid products include (but are not limited to) tea, fruit juices, sports drinks.

The container 2 includes an open cylindrical threaded upper portion or neck 3, which terminates, at an upper end thereof, by an opening or mouth 4 by which the container 2 is capable of being filled and subsequently emptied. Below the neck 3, the container 2 includes a shoulder 5 of increasing diameter in a direction opposite to the neck 3.

Below the shoulder 5, the container 2 has a sidewall 6, which is substantially cylindrical around a container main axis X. The sidewall 6 may, as depicted in FIG.2, include annular stiffening ribs 7 capable of resisting thermal and mechanical stresses undergone by the container 2 during filling, capping and subsequent handling.

At a lower end of the sidewall 6, the container 2 has a base 8, which closes the container 2 and allows it to be normally put on a planar surface such as a table when used by a final customer.

The container base 8 includes a standing ring 9, which may be a high standing ring as it will be explained later, and a central invertible diaphragm 10, which has a symmetry around the main axis X and is deformable with respect to the sidewall 6 between an outwardly-inclined (or lower) position shown on FIG.2, wherein the diaphragm 10 projects outwardly with respect to the container 2, and an inwardly-inclined (or upper) position, shown on FIG.3, wherein the diaphragm 10 projects inwardly with respect to the container 2.

The container 2 is blow molded with the diaphragm 10 in its lower position. As will be explained in further details below, the diaphragm 10 is capable of being mechanically forced upwards (i.e. inwards with respect to the container 2) after the container 2 has been filled with a pourable product, capped and cooled down, in order to compensate for the vacuum generated by the cooling of the product and to increase the overall rigidity of the filled container 2, for the benefits of container handling and customer quality perception.

The standing ring 9 connects to the sidewall 6 of the container at a lower end portion 11 thereof. The standing ring 9 has a support flange 12 adjacent and substantially perpendicular to the lower end portion 11 of the sidewall 6, and a cylindrical or frustoconical inner portion 13, which connects the support flange 12 to the diaphragm 10. The support flange 12 is also substantially perpendicular to the container main axis X.

In a preferred embodiment, the lower end portion 11 of the sidewall 6 has, when viewed in transversal section as shown on FIG.3, the shape of an arch with a concavity turned inward with respect to the container 2, whereby the outer diameter of the support flange 12 is smaller than the overall diameter of the sidewall 6. As depicted, the inner portion 13 preferably has the shape of a frustum of a cone and, when viewed in transversal section as shown on FIG.2, inclines inwardly with respect to the container base 8, with a draft angle.

The cone shape of the inner portion 13 provides a vault stiffening and locking function to the diaphragm 10 in its inverted position (shown in FIG.3), whereby the restriction of diameter of the inner portion 13 at its junction with the diaphragm 10 prevents the latter to articulate back from its inverted position with respect to the inner portion 13. As a result, re- inversion of the diaphragm 10 back to its initial outwardly-inclined position under the mere hydrostatic pressure of the poured product is prevented.

The inner portion 13 has an axial extension, which is important with respect to the outer diameter of the support flange 12, hence the expression "high standing ring" to name the standing ring 9. More specifically, the axial extension (or height) of the inner portion 13 is greater than 1/10 of the outer diameter of the support flange 12, and preferably comprised between 1/10 and 1/5 of the outer diameter of the support flange 12.

In the blown (and filled) configuration of the container 2 depicted on FIG.2, the invertible diaphragm 10 extends outwards in a frusto-conical shape from an outer edge 14 where the diaphragm 10 connects to an upper end of the inner portion 13, to an inner edge 15 where the diaphragm 10 connects to a central upwardly protruding recess 16.

Also in the blown configuration of the container 2, the axial extension, or height, of the diaphragm 10, is such that the inner edge 15 of the diaphragm 10 extends slightly above support plane defined at the junction between the support flange 12 and the lower end portion 11 of the sidewall 6. In other words, the height of the diaphragm 10 is slightly lower than the height of the standing ring 9.

After the container 2 has been blow molded, it undergoes, within a filling unit, a filling step of pouring a product 17 (such as a liquid, e.g. a beverage) through its neck 3 (and more precisely through its mouth 4). The container 2 is normally not fully filled, so that an empty volume (also called headspace) 18, remains above the product 17 within the neck 3. Depending upon the reliability of the filling machine, the volume of poured product 17 may vary from one container 2 to another. As a consequence, the headspace 18 may also vary from one container 2 to another, although the headspace 18 should always be substantially equal in volume to a reference headspace corresponding to the correct volume of dispensed product.

The filled container 2 then undergoes a capping step of sealingly closing the mouth 4 (and hence the container 2) by means of a cap 19 mounted onto the neck 3. In a preferred embodiment, neck 3 and cap 19 are both correspondingly threaded and the cap 19 is screwed onto the neck 3 to provide sealing closure of the container 2.

After having been filled and capped, the container 2 may, in case the product 17 is poured hot, undergo a cooling step, during which the container 2 and its content (product 17) are placed in a cooling tunnel, wherein they are artificially cooled down in a range from about 20°C to 35°C.

After having been capped, and, in the event the container 2 is cooled, after it has been cooled, the container 2 undergoes an inversion phase and a labeling phase.

Although the inversion phase and the labeling phase may be conducted at two different locations by means, respectively, of separate inversion and labeling units, both phases may, as illustrated, be conducted within a same unit.

In the example depicted on FIG.1, the container handling machine 1 includes a plurality of processing units 20 each capable of conducting the labeling of the container 2 and the inversion of its diaphragm 10 to the inwardly-inclined position. Processing units 20 may, as depicted, be mounted onto a carrousel 21 including a frame 22 rotatably mounted around an axis 23 so as to be displaced around a circular path.

In the example of FIG.1, the container handling machine 1 also comprises a rotary transfer unit 24, e.g. under the form of a star wheel provided with a plurality of peripheral gripping devices 25, which grab the filled and capped containers 2 from the capping unit and release each of them at a processing unit 20.

Since processing units 20 are identical, only one will be disclosed in detail hereinafter for the sake of clarity and simplicity.

Each processing unit 20 comprises a hollow container support ring 26 suitable for engaging a container base 8. More precisely, the support ring 26 forms a counter print of at least the support flange 12 and the lower end portion 11 of the container sidewall 6.

The container support ring 26 is rotatably mounted onto the frame 22, e.g. by means of a bearing 27.

The processing unit 20 further includes a container retaining member

28 (only few of which are depicted on FIG.1) for rigidly retaining the container 2 in vertical position with its base located within the support ring 26 while the container 2 is being labeled and while the diaphragm 10 is being inverted.

In the depicted example, the retaining member 28 is provided with a conical head suitable for vertically coming into abutment with the cap 19 along the container axis X.

The processing unit 20 further includes a pusher 29 movable with respect to the frame 22 (and hence to the support ring 26) and capable of coming into abutment with the container base 8 through both the frame 22 and support ring 26 for inverting the diaphragm 10 from its outwardly- inclined position to its inwardly-inclined position.

More precisely, the pusher 29 is slidingly displaceable along axis X for coming into abutment within the central recess 16, as shown on FIG.3. In the depicted example, the pusher 29 has a tip 30, which is complementary in shape to the central recess 16, but the tip 30 may be of a simpler shape, such as a cylinder.

The processing unit 20 further includes an actuator 31 for slidingly moving the pusher 29 frontwards (i.e. upwards) towards the container base 8 through the frame 22 in order to achieve inversion of the diaphragm 10, and backwards (i.e. downwards) thereafter, to be ready for another inversion cycle.

More precisely, in the depicted example, it can be seen that the actuator 31 is a hydraulic or pneumatic cylinder, preferably of the two-way type.

The actuator 31 has a cylinder housing 32, a piston 33 and a rod 34 fixed to the piston 33, with the pusher 29 mounted onto the rod 34 or integral therewith.

In a known manner, the actuator 31 has a closure head 35 and a closure bottom 36 connected through the housing 32. The piston 33 defines within the housing 32 a front chamber 37 around the rod 34 and a back chamber 38 opposite to the rod 34, whereby the front chamber 37 is mainly defined between the piston 33 and the closure head 35 whereas the back chamber 38 is mainly defined between the piston 33 and the closure bottom 36.

The back chamber 38 is in fluidic connection, through a bottom fluid port 39 formed in the closure bottom 36, with a control valve linked to a source of fluid (such as air or oil) under pressure and to a vent. Likewise, the front chamber 37 is also in fluidic connection, through an upper fluid port 40 formed in the closure head 35, with a control valve linked to a source of fluid under pressure and to a vent. The back chamber 38 and front chamber 37 are alternately fluidly connected to the source of fluid and to the vent, so as to move the pusher 29 forth (or up) and back (or down) between a lower position, in which the piston 33 is in the vicinity of the closure bottom 36 (FIG.2), and an upper position, in which the piston 33 is in the vicinity of the closure head 35 (FIG.3).

Position (or height, denoted H) of the pusher 29 vs. time, within a container packaging cycle, is plotted on the uppermost curve of FIG.4. The pusher 29 is initially in its lower position.

Inversion of the diaphragm 10 is conducted as described hereinafter. At instant t₀, the back chamber 38 is connected to the source of fluid and the front chamber 37 to the vent, so that the piston 33, together with the whole pusher 29, begins to move forward (or up), away from its lower position. The pusher 29 moves forward in a linear manner with respect to time as long as it encounters no resistance.

At instant ti (which, in practice, is of about one tenth of a second to few tenths of a second after to), the pusher 29 comes in contact with the container base, and more precisely with the central recess 16. Under the pressure inside the container 2, the container base 8 resists to the upward movement of the piston 33, which is no longer linear in time but asymptotic as the pusher 29 reaches its upper position at instant t₂ (which, in practice, is of few tenths of a second after ti) whereas the diaphragm 10 is inverted to its inwardly-inclined position (FIG.3).

During inversion of the diaphragm 10, the product 17, which is virtually incompressible, is displaced upwardly, whereby the gas (generally air) enclosed in the headspace 18 is compressed by a volume substantially equal to the volume (so-called extraction volume) swept by the diaphragm 10 during its inversion, between its outwardly-inclined and outwardly- inclined positions.

At instant t₂, inversion of the diaphragm 10 is achieved. From instant t₂ and until instant t₃ (which is from few seconds to several tens of seconds), the pusher 29 is held in its upper position to ensure stabilization (and dampen vibrations) of the diaphragm 10 in its inwardly-inclined position and prevent its re-inversion back to its outwardly-inclined position.

From instant t₃ and until instant t₄ (which is of few tenths of a second after t₃), the pusher 29 is moved back to its lower position, which it holds until the next cycle is initiated with another container 2.

Instead of being hydraul ically or pneumatically actuated, the pusher may be electrically actuated by means of an electric motor, such as a linear motor.

In order to conduct the labeling of the container 2, each processing unit 20 comprises a labeling device 41, which, in the depicted example, includes a driving pulley 42 and a driven pulley 43, both rotatably mounted onto the frame 22 (e.g. by means of bearings 44) and connected to each other through an endless labeling belt 45 carrying a label 46 to be affixed onto the container sidewall 6.

The driving pulley 42 may be coupled, through a pinion 47 fixed to the pulley 42 and a driving belt 48, to a motor, which controls rotation and stopping of the driving pulley 42.

One of the pulleys 42, 43 (the driving pulley 42 in the example depicted on FIG.2 and FIG.3) is located in the vicinity of the support ring 26, at a distance such that, when a container 2 is mounted on the support ring 26, the labeling belt 45 is in contact with the container sidewall 6 so as to be capable of wrapping a label 46 therearound as the container 2 is driven in rotation around its axis X by the retaining member 28 and/or by the support ring 26.

The processing unit 20 also includes a glue applicator (not depicted) capable of applying a strip of glue either on an edge of the label 46 or directly on the container sidewall 6 to make the label 46 stick thereto.

Initiation of the labeling phase of the container 2 is based on the timeline of the inversion step (or phase). More specifically, the labeling phase is initiated not later than 10 seconds after completion of the inversion step, i.e. not later than 10 seconds after t₂.

In a first example (Ex.1 on FIG.4), the labeling phase is initiated after completion of the inversion step, i.e. after instant t₂. The advantage of such embodiment is that the container 2 is rigid, due to inversion of the diaphragm 10, which increases pressure inside the container 2.

In a second example (Ex. 2 on FIG.4), the labeling phase is initiated during inversion of the diaphragm 10, i.e. between instants ti and t₂, and ends after completion of the inversion step, i.e. after t₂.

In a third example (Ex. 3 on FIG.4), the labeling phase is initiated before initiation of the inversion step, i.e. before ti, and achieves after completion of the inversion step, i.e. after t₂.

In a fourth example (Ex. 4 on FIG.4), the labeling phase is initiated before initiation of the inversion step, i.e. before t1 , and achieves before completion the inversion phase, i.e. between ti and t₂.

In a fifth example (Ex. 5 on FIG.4), the labeling phase is both initiated and completed before initiation of the inversion step, i.e. before ti.

In any case, the label is firmly affixed to the container, and the use of thinner labels is possible.

Claims

1. Packaging method including the following steps:

a step of providing an empty container (2) comprising a sidewall (6), an open neck (3) and a base (8) including a standing ring (9) and a central invertible diaphragm (10) articulated with respect to the standing ring (9), said diaphragm (10) being in an outwardly-inclined position;

a filling step of pouring a product (17) within the container (2) through the neck (3);

a capping step of sealingly closing the filled container (2) by means of a cap (19) mounted onto the neck (3);

an inversion step of displacing the diaphragm (10) from its outwardly- inclined position to an inwardly-inclined position;

- a labeling step of attaching a label (46) onto the container sidewall (6);

characterized in that the labeling step is initiated before completion of the inversion step and conducted at least partly during the inversion step.

2. Packaging method to claim 1 , wherein the labeling step is initiated before initiation of the inversion step.

3. Packaging method of claim 1 or claim 2, wherein the labeling step is achieved before completion of the inversion step.

4. Packaging method of any of the preceding claims, wherein the labeling step is completed before completion of the inversion step.

5. Packaging method according to any of the preceding claims, wherein the inversion step is conducted by means of a pusher.

6. Packaging method according to claim 5, wherein the pusher is hydraulically or pneumatically actuated.

7. Packaging method according to claim 5, wherein the pusher is electrically actuated.