WO2014029525A1

WO2014029525A1 - A closure

Info

Publication number: WO2014029525A1
Application number: PCT/EP2013/062832
Authority: WO
Inventors: Stephen Faragher; John Howard HALL
Original assignee: Obrist Closures Switzerland GmbH
Current assignee: Obrist Closures Switzerland GmbH
Priority date: 2012-08-24
Filing date: 2013-06-20
Publication date: 2014-02-27
Anticipated expiration: 2015-02-24
Also published as: GB2519278A; GB201502946D0; GB2519278B

Description

A CLOSURE

The present invention relates generally to a closure and particularly to a closure for a hot-fill container.

Hot-fill is a common filling process that involves the sterilising of product prior to being poured into a container. After the hot product is introduced into the container a closure is applied which is used in part to seal the container. As the product cools down inside the container a vacuum is created and this may deform and/or distort the closure, which in turn may affect the seal. It is important that the seal is maintained immediately after capping and also after the product has cooled down.

According to a first aspect of the present invention there is provided a closure for a hot- fill container neck, comprising a top plate and a sidewall, the sidewall is attachable to the outer face of the neck, in which the closure comprises a sealing portion at least part of which extends juxtaposed the inner face of the neck and the sealing portion is urgeable towards the inner face by the top plate.

The sealing portion therefore allows the seal against the interior of container neck to be maintained even if the top plate is pulled down by a vacuum. In addition, after first opening when the vacuum is released the seal will be maintained. In other words, movement of the top plate does not cause the seal to be lost.

The sealing portion may be generally S-shape. A generally sinuous wall section may be provided and merge into the sidewall and top plate. For example, the neck interior may be generally straight and at least part of the section may be "outwardly" curved (i.e. generally convex with respect to the interior wall) . In some embodiments this means that if the top panel moves generally axially under the influence of pressure changes then the curvature of the portion means that it will engage the neck wall to a greater or lesser extent, and may even "roll" along the wall; but at all times at least part of the portion will remain in sealing contact with the interior surface.

The sidewall may be joined to the sealing portion by a shoulder. In use the shoulder may extend over the top of the container neck. The shoulder may carry a depending sealing projection which engages the top of the container neck and helps with the seal. The projection may alternatively or additionally function as a stop block.

The sealing portion may be thinned in the region of its connection to the sidewall. This may help with flexing of the sealing portion to maintain the seal, for example acting like a hinge.

The top panel may be at least partly generally dome-shape, for example convex or concave with respect to the interior of the container. The sealing portion may extend from the periphery of the dome. As the top panel is pulled down in use by the vacuum then this may urge the sealing portion against the container neck inner face i.e. the vacuum may in fact cause the seal to increase.

The sealing portion may be generally parallel to the sidewall. The portion may therefore extend generally parallel to the sidewall but is curved with respect thereto.

The closure may comprise or include a barrier material, which may be provided as a layer, coating or the like. For example the barrier layer may be formed by co-injection and therefore may be provided as an internal layer.

The barrier material may comprise EVOH (ethyl vinyl alcohol copolymer). EVOH has outstanding barrier properties to gases such as oxygen, nitrogen, carbon dioxide and helium. With a very low permeability to oxygen, EVOH can be used to prevent the contents of the container from being deteriorated by contact with oxygen. The opposite face of the sealing portion may also be curved with respect to the container neck inner face. The inner and outer faces of the portion may be generally parallel, although in some embodiments the thickness of the portion varies along its length, for example being thinner at the point of connection to a shoulder region; this allows the thinned region to act like a hinge during pressure-induced movements.

The sidewall may include screw thread formations for engaging corresponding formations on a container neck. Other surface formations, such as snap beads, may alternatively or additionally be used.

In some embodiments the sealing face can seal over a range of positions of the top panel.

According to an alternative aspect there is provided a closure for a hot-fill container neck, comprising a top plate and a sidewall, the sidewall is attachable to the outer face of the neck, the top plate comprises a top panel and an intermediate sealing portion provided between the top panel and sidewall, the sealing portion includes a sealing face for sealing against the inner face of the neck, in which the sealing face is curved with respect to the neck inner face.

According to a further aspect there is provided a closure for a container neck, the closure comprising a top plate and a sidewall, in which the top plate includes barrier material and in which at least part of the top plate extends into the bore of the container neck whereby to position barrier material therein in use. The present invention also provides a container having a closure as described herein.

Different aspects of the invention may be used separately or together. For example barrier material in a top plate may be positioned in the neck bore by using an intermediate portion which extends down inside of the bore so as to carry at least part of the top plate in the bore.

Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with the features of the independent claims as appropriate, and in combination other than those explicitly set out in the claims.

The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a perspective external view of a closure formed according to an embodiment of the present invention; Figure 2 is a side elevation of the closure of Figure 1 ;

Figure 3 is a plan view of the closure of Figures 1 and 2;

Figure 4 is a section of Figure 3 taken along line A-A;

Figure 5 is an enlarged view of the shoulder region of the closure of Figures 1 to 4;

Figure 6 is a section of the closure of Figures 1 to 4 shown as it is partially applied to a container neck; Figure 7 is a section of the closure of Figure 6 shown fully applied to the container neck;

Figure 8 is a section of a closure formed according to an alternative embodiment and shown partially applied to a container neck;

Figure 9 is an enlarged view of the shoulder region of the closure of Figure 8;

Figure 10 is a section of the closure of Figure 8 shown fully applied to the container neck;

Figure 1 1 is an enlarged view of the shoulder region of the closure of Figure 10; Figure 12 is a section of the closure of Figure 10 under the influence of a vacuum;

Figure 13 is an enlarged view of the shoulder region of the closure of Figure 12;

Figure 14 is a perspective external view of a closure formed according to an embodiment of the present invention;

Figure 15 is a section of the closure of Figure 14;

Figure 16 is a section of the closure of Figure 15 shown applied to a container neck; and Figure 17 is an enlarged view of the shoulder region of the closure of Figure 16;

Figure 18 is a section of a closure formed according to an alternative embodiment; and

Figure 19 is a section of a closure formed according to a further embodiment. Referring first to Figures 1 to 3 there is shown a hot-fill closure generally indicated 10.

The closure 10 comprises a generally cylindrical side wall 15 closed at one end by a top plate generally indicated 20.

Referring now also to Figures 4 and 5, the top plate 20 comprises a shoulder region 25 which extends from the sidewall 15, a sealing portion 30 which continues from the shoulder 25 and a central top panel 35 which continues from the portion 30. Together the shoulder 25, portion 30 and the initial part of the panel are generally S-shape.

The interior of the sidewall 15 is provided with a screw thread 16. In this embodiment a 4-start thread is used; in other embodiments single or other types of multi-start threads may be used. In addition, in other embodiments (not shown) alternative retention means, such as snap-on means, may be used.

The interior of the shoulder 25 is provided with a sealing/stop block in the form of an annular projection 26. The sealing portion 30 has a curved inner face 31 which curves towards the sidewall 15. The outer face 32 is not parallel with the inner face 31 and as a result the portion is thinned towards the end at which it extends from the shoulder and provides a thinned zone 33. The top panel 35 is generally dome-shape and extends from the opposite end of the portion 30 to the shoulder 25. This forms a trough 36 between the portion 30 and the panel 35. At the centre of the panel 35 is a depression 37 serving as a gate point. In Figure 6 the closure 10 is shown together with a container neck 50. The neck 50 is generally cylindrical and includes an inner face 52 and an outer face 54. The inner face 52 is generally straight and smooth-sided. The outer face 54 has an external screw thread 56 and a transfer bead 58.

As the closure 10 initially engages the neck 50 the corresponding screw threads 16, 56 engage and the portion 30 begins to engage the inner face 52.

In Figure 7 the closure 10 is shown fully engaged onto the neck 50. The formations 16, 56 are fully engaged and the projection 26 abuts against the upper face 60 of the neck 50. The portion 30 is now axially inserted into the bore of the container neck to form a bore seal. It will be noted that the portion is curved 30 and the corresponding inner face 52 on the neck; a non-parallel interface is therefore provided. In other embodiments a parallel interface is provided.

Referring now to Figures 8 to 13 a closure 1 10 formed according to an alternative embodiment is shown.

The closure 1 10 is very similar to the closure 10 except that a co-formed layer 170 of EVOH is provided.

Figures 8 and 9 show the closure 1 10 prior to full engagement and corresponding to Figures 6 and 7 relating to the closure 10. Accordingly the sealing portion face 131 has started to engage the face 152.

In Figures 10 and 1 1 the closure 1 10 is shown fully engaged on the neck 150, corresponding to Figure 7 relating to the closure 10. The mechanical force of the sealing portion 130 pressing against the face 152 is represented by overlap of the structures, although of course in practice there is no merging of these sealing walls. In use an associated container (not shown) would be filled with hot product and the closure 1 10 would be applied to the neck 150 as represented by Figures 8 to 1 1 . When the product cools the pressure inside the container reduces and the pressure differential created the pulls the top panel 135 down, as illustrated by arrows A in Figures 12 and 13.

Because the panel 135 is outwardly domed, as it is pulled down this causes the sealing portion 130 to be pushed radially outwards as represented by arrow B. Because the portion 130 is curved the outward pressure from the dome increases the mechanical force with which the surface 131 seals against the face 152.

The thinned zone 133 of the sealing portion allows some limited bending movement of the portion 130 with respect to the shoulder 125 to allow for the panel 135 to push the portion 130 outwards whilst the shoulder and sidewall remain fully engaged (they do not move). The increase in mechanical force is again illustrated by overlap of the sealing walls, but in practice there is no merging of the walls, only an increase in sealing force between them. Over time the pressure differential may reduce and this process will be reversed to allow the seal to be maintained as the panel 135 is gradually released.

In Figures 14 to 17 a closure 210 formed according to an alternative embodiment is shown. The closure 210 is similar to the closure 1 10 except that: 1 ) the sealing portion 230 includes a parallel sealing section 280; and 2) the top panel 235 is not a complete dome but instead includes a generally flat central portion 282 surrounded by an inclined annular section 284 that adjoins the sealing portion 230 at the trough 236. In this embodiment therefore the closure has a parallel seal and a non-domed top panel. The closure 210 operates generally in the same way as the closures 10, 1 10 except that the sealing section 280 inner face abuts in a parallel seal against the neck inner face 252. The inclination of the annular wall section 284 causes the panel 235 to urge the section 280 against the inner face to maintain the seal in response to generally axial movement of the top panel cause by variations in internal pressure of an associated container.

Referring now to Figure 18 there is shown a closure 310 formed according to an alternative embodiment.

The closure 310 is very similar to the closure 1 10 and has a co-injected EVOH barrier layer 370 sandwiched in the main polypropylene material of the closure body.

The cross sectional profile of the closure 310 is designed to place the EVOH barrier material inside the container bore (whereas with a conventional bore seal closure co- injected EVOH would not get inside this area).

Any negative pressure inside the sealed chamber following hot-filling creates a pressure differential which pull the convex top deck 335 down, thus applying radial pressure on the inside of the bore seal and increasing bore seal pressure.

In this embodiment the closure sidewall 315 has a tamper-evident band 385. The band 385 is frangibly connected to the free end of the sidewall and the interior of the band is provided with an upturned flap 387 which lodges under the container neck transfer bead 358 upon application. When the closure is subsequently removed for the first time the band is broken away from the sidewall and remains on the neck whilst the remainder of the closure is removed, as evidence of opening. Referring now †o Figure 19 there is shown a closure 410 formed according to an alternative embodiment.

The closure 410 is very similar to the closure 310, except that a different tamper-evident system is provided.

In this embodiment a separate tamper-evident member 490 is provided. The member is an annulus comprising a retained annulus 492 and a drop annuls 494 which are formed so as to be frangibly connected to each other as shown.

The retained annuls 492 is clipped into the closure using a snap bead 416 at the free end of the sidewalk

The drop annuls 494 includes an upturned retention flap 495 which engages under the container neck transfer bead when the closure is initially applied to the neck in use.

When the closure is opened for the first time the retained annulus 492 is held in the closure and the drop annulus breaks away, remaining on the neck. Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

Claims

1 . A closure for a hot-fill container neck, comprising a top plate and a sidewall, the sidewall is attachable to the outer face of the neck, in which the closure comprises a sealing portion at least part of which extends juxtaposed the inner face of the neck and the sealing portion is urgeable towards the inner face by the top plate.

2. A closure as claimed in Claim 1 , in which at least part of the sealing portion extends generally parallel to the inner face.

3. A closure as claimed in Claim 1 or Claim 2, in which at least part of the sealing portion is curved with respect to the inner face.

4. A closure as claimed in any preceding claim, in which the sealing portion in generally S-shape.

5. A closure as claimed in any preceding claim, in which the sidewall is joined to the sealing portion by a shoulder.

6. A closure as claimed in Claim 5, in which the sealing portioned in thinned in the region of its connection to the sidewall.

7. A closure as claimed in Claim 5 or Claim 6, in which the shoulder comprises a stop block.

8. A closure as claimed in any preceding claim, in which the top plate is generally dome-shape.

9. A closure as claimed in any preceding claim, in which the top panel is convex with respect to the interior of the container.

10. A closure as claimed in any preceding claim, in which the top panel urges the sealing portion against the container neck inner face.

1 1 . A closure as claimed in any preceding claim, in which the sealing portion is generally parallel to the sidewall.

12. A closure as claimed in any preceding claim, in which the closure comprises or includes a barrier material.

13. A closure as claimed in Claim 12, in which the battier material is provided as a layer.

14. A closure as claimed in Claim 12 or Claim 13, in which the barrier layer is formed by co-injection.

15. A closure as claimed in any of Claims 12 to 14, in which the barrier material comprises EVOH.

16. A closure as claimed in any preceding claim, in which the opposite face of the sealing portion is also curved with respect to the container neck inner face.

17. A closure as claimed in any preceding claim, in which the sidewall includes screw thread formations.

18. A closure for a hot-fill container neck, comprising a top plate and a sidewall, the sidewall is attachable to the outer face of the neck, the top plate comprises a top panel and an intermediate sealing portion provided between the top panel and sidewall, the sealing portion includes a sealing face for sealing against the inner face of the neck, in which the sealing face is curved with respect†o the neck inner face.

19. A closure for a container neck, the closure comprising a fop plafe and a sidewall, in which the top plafe includes barrier maferial and in which af leasf part of the top plafe extends into the bore of the container neck whereby†o position barrier material therein in use.

20. A closure substantially as hereinbefore described with reference †o, and as shown in, the accompanying drawings.

. A container having a closure as claimed in any preceding claim