EP2172405A1

EP2172405A1 - Closing membrane for a container, having an improved access-finger

Info

Publication number: EP2172405A1
Application number: EP08305630A
Authority: EP
Inventors: Guy Jacques Ducrot
Original assignee: Impress Group BV
Current assignee: Trivium Packaging Group Netherlands BV
Priority date: 2008-10-01
Filing date: 2008-10-01
Publication date: 2010-04-07

Abstract

The present invention relates to a membrane (1) suitable for closing an opening (6) of a container, directly or indirectly via a lid (2'), said closing membrane (1) comprising - a central flexible peelable foil (8), and - at least one grip tab (9).
According to the invention, said membrane (1) is provided with at least one local deformation (11, 12) of curved shape, which delimits a curved housing (11a, 12a) having at least one opening (11b, 12b) to allow a finger access to said housing (11a, 12a); and said curved deformation (11, 12) is arranged about the tab (9), advantageously onto the tab (9) and/or the foil (8), to allow the access of the user finger to the lower face (9a) of said tab (9).

Description

The present invention relates to the field of the packages or containers sealed and closed by a membrane of "peelable" type, i.e. an organ comprising a peelable foil, equipped with at least a gripping tab.
This kind of container is typically used for conditioning foodstuffs, but it can also be used for conditioning some other industrial products, such as paints for example.
The peelable containers, for example described in document EP-1 878 666 , comprise a body, generally made of metal material, on the upper edge of which a sealing membrane is fastened, advantageously directly or indirectly via a lid ring provided by a seaming operation.
The sealing lids consist generally in a metal ring having - an outer annular part intended to be seamed with the upper edge of the container body, and - an inner annular part having a flange shape and whereof the upper face receives by bonding and by sealing a peelable flexible foil.
It is desirable for the consumer to be able to peel the foil off the upper edge of the container or off the metal ring, with relatively little force so that people of diverse ages and abilities can open the container, and so that the foil comes off cleanly in one piece rather than tearing.
To this aim, most of the peelable foils are equipped with a grip or pull tab, intended to allow the consumer to apply a peel force in order to separate the membrane from the container.
In practice, the said tab should be closely lying with the peelable foil. In particular, during sterilisation process of the container and then stacking of the latter, the tab should not rise up, but stay as close as possible to the foil.
Still, the tab must be easily gripped by the consumer when he wishes to open the container; the user must thus preferably have an efficient "finger access" or "access-finger" to the tab.
To solve this problem and to comply with these requirements, the applicant has developed a new structure of membrane, allowing an efficient arrangement of the tab against the peelable foil and simultaneously an optimal finger access to the tab for the consumer.
The closing membrane according the invention comprises - a "peelable" central foil, whereof an outer border is suitable to be sealed with the edge of the container (i.e. the integral edge of the container body or a lid ring) which delimits an opening , and - at least one grip tab, lying at least in part substantially parallel and close to the upper surface of said central foil, said grip tab having an inner free end and an outer fixed end extending from the outer border of said central foil.
The membrane, in accordance with the present invention, is provided with at least one local deformation of advantageously curved shape, which delimits a housing (advantageously curved) having at least one opening to allow an access finger to said housing, and said curved deformation being arranged about the tab to allow the access of the user finger(s) to the lower face of said tab.
According a first embodiment, the tab is advantageously provided with at least one curved deformation, said deformation being of convex shape starting from the upper surface of the foil, the opening of said deformation being defined by the tab border.
In this case, the said curved deformation is advantageously arranged - at the inner free end of the tab, or - between its outer fixed end and inner free end.
The tab can also advantageously be provided with at least such two deformations: one "terminal" at its inner free end, and at least another "lateral" between its ends.
Also according this case, the tab deformation(s) has advantageously a maximal height comprised between 1 mm and 20 mm (and preferably between 2 mm and 5 mm), and a width narrower, or equal, than the tab width.
According another embodiment, the central foil is advantageously provided with at least one curved deformation of concave shape, starting from the upper surface of the foil, said curved deformation having an opening delimited by a peripheral edge extending about the tab.
In this case, the curved deformation of the foil extends advantageously outside the overall dimensions of the tab, a part of the peripheral edge of said curved deformation extending tangentially, or at least nearly tangentially, to the border of said tab.
Alternatively, a part of the curved deformation of the foil extends advantageously inside the overall dimensions of the tab (i.e. in other words, under the tab).
Also according this second embodiment, the curved deformation of the foil is arranged advantageously about the inner free end of the tab and/or between the inner fixed end and outer free end of said tab.
The foil can also advantageously be provided with at least two deformations:

one "terminal" at the inner free end of the tab and at least another "lateral" between the ends of the latter.
The said curved deformations can advantageously extend inside or outside the overall dimensions of the tab.

Preferably, the said curved deformation of the foil has a depth comprised between 1 mm and 20 mm (and preferably between 1 mm and 5 mm), and an area comprised between 10 mm² and 1 000 mm².
Moreover, the tab and the foil can be, advantageously, each provided with at least one curved deformation as specified here-above.
The present invention concerns also a lid for container comprising (i) a lid ring having at least an inner annular surface which is intended to define the inner opening of said container, and (ii) a membrane as above-disclosed, whereof an outer border of the central foil is sealed with said annular surface of said lid ring.
The invention is moreover directed to a container equipped with at least a membrane according the above definition or at least a lid according also the above definition.
The present invention relates also to a method for preparing and forming a membrane of the type specified here-above.
According this method, the membrane is machined at least by a drawing step, to provide it with at least one local plastic deformation of curved shape, which delimits a curved housing having at least one opening to allow an access finger to said housing, and said curved deformation being arranged about the tab to allow the access of the user finger(s) to the lower face of said tab.
In accordance with a specific embodiment in which at least a convex deformation is formed onto the tab and a concave deformation onto the peelable foil, the following steps are advantageously implemented: first, a convex deformation is made simultaneously on the foil and on the tab, the convex deformation of the foil being arranged only in part in the overall dimension of said tab, and second, a vacuum force is applied to the lower surface of the foil so as to provoke the moving of the foil deformation from the convex shape to the concave shape (e.g. this vacuum force corresponds to a following sterilization operation implemented on the container equipped of said membrane).
The present invention is illustrated by the description of the following embodiments, in accordance with the figures enclosed in which:

figure 1 is a perspective and cross-section view of a first embodiment, whereof a lid is fitted with a closure membrane according to the invention which is provided with two curved access-finger deformations: one arranged onto the pull tab and the other onto the foil;
figure 2 is a side and cross-section view of the lid of figure 1, according to a vertical section extending through the two deformations;
figure 3 is also a perspective and cross-section view of the closing membrane of figures 1 and 2, the latter being here directly sealed onto a curled/rolled edge of the container;
figure 4 is a side and cross-section view of the assembly of figure 3, according to a vertical section extending through the two deformations;
figure 5 is another perspective and cross-section view of the closing membrane of figures 1 and 2, said membrane being here directly sealed onto a container edge in shape of outwardly extending annular flange;
figure 6 is a side view of the assembly of figure 5, according to a vertical section extending through the two deformations
figure 7 is a perspective view of a second embodiment of the closing membrane, whereof the foil deformation is arranged outside the overall dimensions of the tab;
figure 8 is a side and cross-section view of the closing membrane of figure 7, according to a vertical section extending through the two deformations;
figure 9 is a perspective view of a third embodiment of the closing membrane, whereof only the tab is here provided with a curved deformation;
figure 10 is a perspective view of a fourth embodiment of the closing membrane, whereof the pull tab is provided with two curved deformations;
figure 11 is a cross-section and perspective view of a fifth embodiment, whereof only the foil is provided with an access-finger deformation;
figure 12 is perspective view of a sixth embodiment, whereof the foil is provided with two curved deformations: an access-finger deformation and a positioning-finger deformation;
figure 13 shows schematically the main steps of a possible method for preparing and forming a closure membrane according to the invention.

The closing membrane 1 according to the invention, as shown figures 1 to 12, is suitable for making containers with at least a sealing foil of the "peelable" type, and more particularly an "easy" peelable foil.
The said membrane 1 is suitable to be affixed / fastened, according a seal assembly, on the upper edge of a container body.
As disclosed here-after, this closing membrane 1 can be sealed directly onto a body edge of the container which delimits an opening, or alternatively in an indirect way by mean of a lid constituted of said membrane provided with a seaming ring.
The container body has in particular a side wall which can have various configurations and cross-sectional shapes. A circular cross-section is advantageous, but alternatively this body can have other shapes such as oval, square or rectangular, oblong, etc.
The container body can be made of various materials and by various processes. For instance, the container body can be made of metal, e.g. steel or aluminium, chosen in function of the product intended to be conditioned.
This kind of container is typically used for the conditioning of foodstuffs, but it can also be used for conditioning some other industrial products, such as paints for example.
In first embodiment shown figures 1 and 2, the closing membrane 1 according to the invention is sealed onto a metal ring 2.
The membrane 1 / ring 2 assembly forms together a lid 2', intended to be sealed onto a body edge of the container. In this embodiment, the closing membrane 1 is thus suitable to be sealed indirectly onto said body edge of the container.
The ring 2 is for example made of steel or of aluminium.
The shape of the ring 2 is adapted in function of the cross-sectional shape of the container body. For instance, it is here of annular or circular shape.
As shown in particular figure 2, this ring 2 comprises a planar annular flange 3 delimited, on the one hand, by a rolled or curled inner border 4, and on the other hand, by a free outer curl part 5 arranged to be seamed on the edge of the container body (not shown).
The membrane 1 according to the invention, forms a removable closure mean, which is intended to seal an inner opening 6 delimited by the said inner border 4 of the ring 2.
When the lid 2' is affixed / fastened on the container body, said opening 6 allows the access to the conditioned product after removing a said closure mean 1.
The said closing membrane 1 comprises a flexible foil 8 of peel type, having an upper surface 8a and a lower surface 8b.
The peripheral border of the said foil lower face 8b is bonded and fastened, in a sealing assembly (for example by heat sealing), to the upper face of the annular flange 3 of the ring 2.
Such a flexible foil 8 is disclosed, for instance, in document EP-1 878 666 .
At a zone of its peripheral border, the peelable foil 8 comprises also a grip or pull tab 9, lying over and closely to its upper face 8a.
The function of this tab 9 is to be readily grasped and pulled to remove the foil 8 from the ring 2.
In particular embodiments, the foil 8 may be provided with two, or more, such tabs 9.
This pull tab 9 is integral with the foil 8, and consists of a material / matter extension (the closing membrane 1 being made in one piece).
Alternatively, the pull tab 9 is affixed/fastened to the foil 8, directly or indirectly via an intermediary piece (the closing membrane 1 being thus made at least of two pieces).
This pull tab 9 has here a quadrangular shape, e.g. a rectangular shape.
The longitudinal axis 9' of said tab 9 extends here radially, or at least approximately radially.
This pull tab 9 comprises two ends: - an outer fixed end 10a, associated to the outer border of the foil 8 and consisting advantageously in an integral fold portion, and - an inner free end 10b, arranged towards the centre of the foil 8 (said longitudinal axis 9' extending along said inner and outer ends).
The peripheral borders of said pull tab 9 define a horizontal overall dimension, also named horizontal encumbrance, onto the surface of the foil 8.
According to the invention, the closing membrane 1, constituted by the foil 8/tab 9 assembly, is provided with local deformations 11, 12, which delimits each a housing 11a, 12a having an opening 11b, 12b to allow an access finger to said housing.
Theses deformations 11, 12 are arranged about the tab 9 (directly onto the tab 9 and/or onto the foil 8) to allow the access of the user finger(s) to the lower face 9a of said tab 9. This permits the user to move his finger(s) below the tab 9, to grip and to tear up the latter, and to peel off the foil 8.
The local deformations 11, 12 are advantageously of curved shape, which is particularly interesting by the fact that it is significatively resistant to mechanic stress, notably during sterilisation, transport, storage, etc.
The shape of the local deformations 11, 12 can also be termed "arched", "domed", "rounded" or "warped".
As disclosed after, said local deformations 11, 12 are advantageously plastic deformation or plastic deformation type (i.e. deformation of a material undergoing non-reversible changes of shape in response to applied forces), which are obtained for example by drawing and/or warping operation(s).
The membrane 1, i.e. the foil 8 and/or the tab 9, is thus preferably made in a material suitable to be shaped by such plastic deformations; one skill in the art can choose such a material and the process to implement.
According the first embodiment of the invention as shown figures 1 and 2, the closing membrane 1 comprises two local "access-finger" deformations 11, 12, i.e. a first deformation 11 arranged onto the pull tab 9 and a second deformation 12 arranged onto the foil 8.
The said tab deformation 11 is of convex shape, starting from the upper surface 8a of the foil 8, and is arranged at the inner free end 10b of said tab 9.
This deformation 11 is here of half dome shape. It is oriented coaxially with the longitudinal axis 9' of the tab 9.
The width of this deformation 11 is inferior to the one of the said pull tab 9, as shown figure 1.
The opening 11b of said deformation 11 is defined by the inner end border 11c of the tab 9, here of arc of circle shape (in particular a semi-circle).
This tab deformation 11 has advantageously a height and a depth comprised between 1 mm and 20 mm (preferably between 2 mm and 5 mm).
The foil deformation 12 is of concave dome shape, starting from the upper surface 8a of the foil 8 (this deformation 12 extends at side of the foil lower surface 8b). Said foil access-finger deformation 12 has an opening 12b, oriented upwardly, delimited by an annular peripheral edge 12c extending about the tab 9.
In the present embodiment, the curved deformation 12 of the foil 8 is arranged about the inner end 10b of the tab 9, and in part inside the overall dimensions of the tab 9.
The tab 9, in particular the inner end 10b thereof, extends thus above the foil deformation 12 and in regard of its opening 12b.
For instance, the curved deformation 12 of the foil 8 has a depth comprised between 1 mm and 20 mm (preferably between 2 mm and 5 mm), and an area comprised between 10 mm² (corresponding to a nail size) and 1 000 mm² (corresponding to the size of at least two fingers).
Thus, the said two deformations 11 and 12 constitute together a broader housing, constituted by their respective housings 11a and 12a. The consumer has then an optimal finger(s) access to the pull tab 9.
Moreover, the terminal position of the curved deformation 11, at the inner end 10b of the tab 9, permits better and natural gripping characteristics of said tab.
The membrane 1 above-described can also be directly sealed onto the body edge of the container as shown figures 3 to 6.
For instance, as shown figures 3 and 4, the body container C comprises an integral edge C1 having a curled / rolled shape, extending here outwardly. This edge C1 delimits the opening 6 of the body container C.
The peripheral border of the foil lower face 8b is bonded and fastened, in a sealing assembly, to this body edge C1.
As shown figures 5 and 6, the body container C can also comprise an integral edge C2 having an annular flange shape, extending here outwardly. The inner border of this edge C2 delimits the opening 6 of the body container C.
The peripheral border of the foil lower face 8b is bonded and fastened, in a sealing assembly, to the upper face of the container annular flange C2.
The embodiment of figures 7 and 8 differs only by the position of the foil deformation 12, compare to the first embodiment of membrane disclosed here-above.
This closing membrane 1 comprises thus a tab 9 whereof the inner end 10b is provided with a local deformation 11, identical or at least similar to the one disclosed here-above in accordance with figures 1 and 2.
According the present embodiment, the foil access-finger deformation 12 is here arranged outside the overall dimensions of the tab 9. Moreover, a part of the peripheral edge 12c of said curved deformation 12 extends tangentially to the inner border 11c of said tab 9.
In other word, said inner tab border 11c and said deformation edge 12c extends into, or approximately into, the same transversal plan P which is perpendicular to the foil 8 (as shown figure 8).
In some other embodiments, only the foil 8 or the tab 9 can be provided with one of the above-disclosed deformations 11, 12.
Theses curved deformations 11, 12 are also arranged about the tab 9 (onto the foil 8 or said tab 9), to allow the access of the user finger to the lower face 9a of said tab 9.
For example, in the case of the embodiment shown figure 9, the foil 8 of the membrane 1 can be totally planar and rests against most of the lower face 9a of the tab 9. This is in particular interesting if said foil 8 is provided with an impression which should not be deformed.
The deformation 11 is thus arranged here only onto the tab 9.
As shown here, the tab 9 comprises a terminal inner deformation 11 as disclosed before.
This access-finger deformation 11 is sufficient to allow the gripping of the tab 9 by the consumer.
According to the particular embodiment shown figure 10, the tab 9 comprises an optional and complementary deformation 13.
This second tab deformation 13 can be arranged onto any other embodiment of membrane 1.
The second tab deformation 13, said "lateral" deformation, is arranged laterally onto the tab 9, between its outer 10a and inner 10b ends.
The lateral deformation 13 is also opened laterally, i.e. transversally compare to the longitudinal axis 9' of the tab 9.
This second tab deformation 13 is identical, or at least similar, to the terminal access-finger deformation 11 above-disclosed.
It is thus of convex shape, starting from the upper surface 8a of the foil 8, and in particular of half dome shape. It delimits also a curved housing 13a having one lateral opening 13b defined by the tab lateral border 13c.
The tab 9 can also be provided with another lateral deformation, in particular to allow the tab gripping either by a right hand user or a left hand user.
In practice, this tab shape, with multiple access-finger deformations 11, 13, allows thus its efficient gripping, either into the axis 9' of the tab 9 or transversally to it.
Alternatively, as shown figures 11 and 12, the tab 9 can be planar and rests against the foil upper face 8a.
The unique/single access-finger deformation 12 is thus arranged here onto the foil 8, about the tab 9.
As shown figure 11, this access-finger deformation 12 extends into the overall dimensions of the tab 9, as disclosed above in accordance to figures 1 and 2. The tab 9 extends thus partially above the foil deformation 12.
As shown figure 12, the foil deformation 12 can also be arranged tangentially to the tab 9 (i.e. outside the overall dimensions of the tab 9) about the inner free end 10b thereof, as disclosed above according to figures 7 and 8.
The embodiment of figure 12 comprises also a foil 8 provided with a complementary and optional curved deformation 14.
The aim of this complementary deformation 14 is to optimize the finger positioning of the consumer, when he wishes to grip the tab 9 and to peel off the foil 8.
This second foil deformation 14 can be arranged onto any other embodiment of closure membrane 1.
This lateral deformation 14 is also of concave shape, compare to the upper surface 8a of the foil 8.
It is arranged, on the one hand, about a lateral border of the tab 9 (extending between its outer end 10a and inner end 10b), and on the other hand, outside the overall dimensions of the tab 9.
It also delimits a curved housing 14a having one opening 14b, defined by a border 14c.
According an interesting embodiment, the foil 8 can be provided with such two foil lateral deformation 14, each one at one side of the tab 9 to allow the finger positioning either for a right hand user or for a left hand user.
An advantageous method for preparing and forming a membrane according to the invention consists in machining the said membrane by at least a drawing step.
This drawing operation is implemented onto the foil 8 and/or the tab 9 so as to provide the membrane 1 with at least one local plastic deformation of curved shape as disclosed above.
A particular method is shown figure 13, which is intended to form a closure mean of the type disclosed above in accordance with figures 1 and 2.
As shown, the corresponding method comprises the following steps:

a closing membrane 1 is provided, eventually fastened to a lid ring as abovementioned, said closing membrane 1 being composed of a planar central foil 8 of "peelable" type, and of a planar grip tab 9, extending from an outer border of said central foil 8 and lying substantially parallel and closely to an upper surface of said central foil 8 (figure 13 A),
a drawing operation is suitably implemented onto said closing membrane 1, to form simultaneously two convex deformations 11, 15, respectively onto said tab 9 and onto said foil 8; the foil convex deformation 15 extends only in part within the overall dimension of said tab 9 (figure 13 B), and
a vacuum force is applied to the lower surface 8b of the foil 8 so as to provoke the moving of the foil convex deformation 15 to a concave shape 12 as disclose before (figure 13 C); the deformation 11 of the tab 9 remains in convex position.

This closing membrane 1 can then be sealed onto a lid ring (for instance according to figures 1 and 2) or onto the edge of a body container (according for example to figures 3 to 6).
Advantageously, the vacuum force corresponds to a following sterilization operation implemented on the container equipped of said closing membrane 1, in a state as specified in accordance with figure 13 B.

Claims

A membrane suitable for closing an opening (6) of a container, said closing membrane (1) comprising - a central flexible peelable foil (8), whereof an outer border is suitable to be sealed with the edge of said container which delimits said opening (6), and - at least one grip tab (9), lying at least in part substantially parallel and closely to an upper surface (8a) of said central foil (8), said grip tab (9) having an inner free end (10b) and an outer fixed end (10a) extending from an outer border of said central foil (8),
characterised in that said closing membrane (1) is provided with at least one local deformation (11, 12, 13, 14) of curved shape, which delimits a curved housing (11a, 12a, 13a, 14a) having at least one opening (11b, 12b, 13b, 14b) to allow a finger access to said housing (11a, 12a, 13a, 14a), and said curved deformation (11, 12, 13, 14) being arranged about the tab (9) to allow the access of the user finger(s) to the lower face (9a) of said tab (9).
A closing membrane according to claim 1, characterised in that the tab (9) is provided with at least one curved deformation (11, 13), said deformation (11, 13) being of convex shape starting from the upper surface (8a) of the foil (8), the opening (11b, 13b) of said deformation (11, 13) being defined by the tab border (11c, 13c).
A closing membrane according to claim 2, characterised in that the curved deformation (11) is arranged at the inner free end (10b) of the tab (9).
A closing membrane according to any of the claims 2 or 3, characterised in that the curved deformation (13) is arranged between its outer fixed end (10a) and inner free end (10b).
A closing membrane according to any of the claims 2 to 4, characterised in that the tab deformation(s) (11, 13) has a maximal height comprised between 1 mm and 20 mm, and a width narrower, or equal, than the tab width.
A closing membrane according to any of the claims 1 to 5, characterised in that the central foil (8) is provided with at least one curved deformation (12, 14) of concave shape, starting from the upper surface (8a) of the foil (8), said curved deformation (12, 14) having an opening (12b, 14b) delimited by a peripheral edge (12c, 14c) extending about the tab (9).
A closing membrane according to claim 6, characterised in that the curved deformation (12, 14) of the foil (8) extends outside the overall dimensions of the tab (9), a part of the peripheral edge (12c, 14c) of said curved deformation (12, 14) extending tangentially, or at least nearly tangentially, to the border of said tab (9).
A closing membrane according to claim 6, characterised in that a part of the curved deformation (12) of the foil (8) extends inside the overall dimensions of the tab (9).
A closing membrane according to any of the claims 6 to 8, characterised in that the curved deformation (12) of the foil (8) is arranged about the inner free end (10b) of the tab (9).
A closing membrane according to any of the claims 6 to 8, characterised in that the foil (8) comprises a lateral curved deformation (14) which is arranged between the inner fixed end (10b) and the outer free end (10a) of the tab (9).
A closing membrane according to any of the claims 6 to 10, characterised in that the curved deformation (12, 14) of the foil (8) has a depth comprised between 1 mm and 20 mm and an area comprised between 10 mm² and 1 000 mm².
A closing membrane according to any of the claims 1 to 11, characterised in that the tab (9) and the foil (8) are each provided with at least one curved deformation (11, 12, 13, 14).
Lid for container comprising (i) a lid ring (2) having at least an inner annular surface (3) which is intended to define the inner opening (6) of said container and which is suitable to be sealed onto a edge of said container, and (ii) a membrane (1) according to claims 1 to 12, whereof an outer border of its central foil (8) is sealed with said annular surface (3) of said lid ring (2).
Container equipped with at least a closing membrane (1) according any of the claims 1 to 12, directly onto a body edge (C1, C2) or indirectly via a lid (2') according to claim 13.