US20180118413A1

US20180118413A1 - Closure system with distinct breaking forces

Info

Publication number: US20180118413A1
Application number: US15/564,852
Authority: US
Inventors: Pierre-Yves LINOT; Thierry Marche
Original assignee: Aplix SA
Current assignee: Aplix SA
Priority date: 2015-04-13
Filing date: 2016-04-08
Publication date: 2018-05-03
Also published as: CN107690408A; FR3034759A1; EP3283387A1; JP2018511537A; WO2016166454A1

Abstract

A closure system includes a first unit that includes a base presenting two opposite faces, a first retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base. The closure system also includes a second unit comprising a base presenting two opposite faces, a second retaining element arranged on the first face of the base and adapted to engage the first retaining element, and a bonding layer arranged on the second face of the base. The closure system is characterized in that the bonding layer of at least one of said units comprises two bonding portions presenting distinct breaking forces.

Description

GENERAL TECHNICAL FIELD

The present invention relates to the field of closure systems, finding its application in particular in making reclosable bags, or more generally for products requiring an attachment or closure system that is reusable, in particular in the food industry, and also in the medical or hygiene field.

STATE OF THE ART

Reusable closures are commonly used in numerous domains, and they may be made in several ways.
Thus, by way of example, closures are known that are made by means of complementary section members arranged on two elements that are to be assembled together, or closures are known that are made by means of loop-and-hook or indeed hook-and-hook type systems that form units commonly referred to as self-gripping units, i.e. units in which the hooks and loops attach together reversibly on being put into contact.
A recurring problem with such closures is to ensure that the closed state is well maintained, while still being easy for a user to open and close.
Several types of closure element have thus been proposed, in order to make connections having a profile that is asymmetric; the force required for separating such a connection depends in particular on the type of effort that is exerted.
Furthermore, closure systems must be capable of being assembled on the intended product, which leads to major requirements in terms of guidance and strength during assembly on an article.
Finally, closure systems must be supplied that are free of any contamination, in particular in the fields of hygiene and food, in particular in the light of certain standards, such as the BRC/IOP standard for the food industry.

SUMMARY OF THE INVENTION

The present invention seeks to propose a closure system satisfying these various problems, at least in part, and thus proposes a closure system comprising:

- a first unit comprising a base presenting first and second opposite faces, a first retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base and adapted to enable the first unit to be secured on a support surface; and
- a second unit comprising a base presenting first and second opposite faces, a second retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base and adapted to enable the second unit to be secured on a support surface;

the first and second retaining elements being configured to engage in such a manner as to make a reclosable connection;
the system being characterized in that the bonding layer of at least one of said units comprises two bonding portions, each configured to secure said units on a support surface, and presenting distinct breaking forces.
The closure system optionally presents one or more of the following characteristics, taken independently or in combination:

- the bonding layer of at least one of said units includes empty portions such that the bonding portions of said at least one unit are disjoint in full or in part; at least one of the empty portions may then define a closed cavity, including a sensory marker;
- each unit further comprises a soleplate forming a support surface, each base being secured to a first face of the associated soleplate by means of its bonding layer; said bonding layers are then made by way of example by heat-sealing said units on the soleplates;
- in a variant of the above characteristics, said at least one closed cavity is defined by the base, the soleplate, and the bonding portions of the unit under consideration;
- for said at least one unit having two bonding portions presenting distinct breaking forces, the bonding portions define two distinct breaking forces Fr1 and Fr2, and the retaining elements define an opening force F, with said forces being such that Fr1<F<Fr2;
- each of said retaining elements is formed integrally with the associated base, and where appropriate also with the associated bonding layer;
- said retaining elements comprise fields of retaining elements, at least one of said retaining elements comprising hooks;
- at least one of said retaining elements comprises a section member extending in a longitudinal direction;
- the first and second units are joined, forming a single unit; and
- the bonding layer of each of said units comprises at least two bonding portions presenting distinct breaking forces.

The invention also provides a container having two side walls defining an opening giving access to an inside volume, said container including a closure system as defined above arranged on its side walls so as to form a reclosable opening.
In another particular embodiment, each unit has an internal border and an external border, the internal border being arranged in the inside volume of the container, and the external border being arranged outside of the inside volume of the container, the bonding layer of at least one of the units comprising an inner portion and an outer portion presenting distinct breaking forces, and is configured so that its inner portion presents a breaking force that is smaller than the breaking force of its outer portion.
In another particular embodiment, each unit has an internal border and an external border, the internal border being arranged in the inside volume of the container, and the external border being arranged outside of the inside volume of the container, the bonding layer of at least one of the units comprises an inner portion and an outer portion presenting distinct breaking forces, and is configured in such a manner that its outer portion presents a breaking force that is smaller than the breaking force of its inner portion.
In another particular embodiment, each unit has an internal border and an external border, the internal border being arranged in the inside volume of the container, and the external border being arranged outside of the inside volume of the container, the bonding layer of each of the units comprise an inner portion and an outer portion presenting distinct breaking forces, the bonding layer of one of the units is configured so that its outer portion presents a breaking force smaller than the breaking force of its inner portion, and the bonding layer of the other unit is configured in such a manner that its inner portion presents a breaking force less than the breaking force of its outer portion. More particularly, the bonding portion presenting a smaller breaking force is located at least in part in a zone defined by the projection of the first and/or second retaining elements.

SUMMARY OF THE FIGURES

Other characteristics, objects, and advantages of the invention appear from the following description, which is purely illustrative and non-limiting, and which should be read with reference to the accompanying drawings, in which:

FIG. 1 shows an example of a system in an aspect of the invention;

FIG. 2 shows another example of a system in an aspect of the invention;

FIGS. 3 to 10 show various other examples of systems in an aspect of the invention in association with a container such as a bag; and

FIGS. 11 and 12 are graphs illustrating the effect of the system as described.

In the figures, elements that are in common are identified by numerical references that are identical.

DETAILED DESCRIPTION

FIG. 1 shows an example of a system in an aspect of the invention.
This figure shows a closure system comprising two units 100 and 200 adapted for making a reclosable connection.
Each unit comprises a base having first and second opposite faces, a retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base and adapted to enable the unit to be secured on a support surface.
Thus the first unit 100 has a base 110 presenting first and second faces 112 and 114 that are opposite, a retaining element 120 arranged on the first face 112 of the base 110, and a bonding layer 130 arranged on the second face 114 of the base 110 and adapted to enable the first unit 100 to be secured on a support surface, not shown in this figure.
Likewise, the second unit 200 comprises a base 210 presenting first and second faces 212 and 214 that are opposite, a retaining element 220 arranged on the first face 212 of the base 210, and a bonding layer 230 arranged on the second face 214 of the base 210 and adapted to enable the second unit 200 to be secured on a support surface, not shown in this figure.
The bonding layers 130 and 230 may be of any type, and in particular they may be made by gluing or by heat-sealing with or without added material.
The retaining elements 120 and 220 of the first and second units are configured to engage each other in such a manner as to make a reclosable connection, e.g. of the self-gripping or contact-closure type.
In the example shown, the retaining elements 120 and 220 are fields of hooks or the equivalent, thus forming a male-male type connection, such that putting the two retaining elements 120 and 220 into contact and possibly applying pressure thereon causes them to become mutually engaged.
The retaining elements 120 and 220 may extend independently over the entire width of their bases 110 and 210, they may have a plurality of fields of retaining elements, or they may have a single field of retaining elements, as shown in the figures.
The retaining elements 120 and 220 may be of any type, in particular continuous units made by extrusion, fields of discrete elements potentially extending in parallel longitudinal lines or indeed being arranged in a staggered configuration, or a combination of continuous units and discrete fields of elements. Various other embodiments are described below. The retaining elements 120 and 220 may be formed integrally with the associated bases.
The first and second units 100 and 200 may also form a single unit, as explained below with reference to FIG. 10. The retaining elements 120 and 220 then typically define a portion of that single unit that is adapted to break on application of an external or internal force as a function of the application.
Such an embodiment is particularly advantageous for example when applied to a bag, and more particularly for a pouring spout or indeed when the unit is applied continuously to the entire perimeter of the bag.
As shown in FIG. 1, the bonding layer of at least one of the units 100 and 200 comprises two bonding portions presenting distinct breaking forces.
In the example shown, the bonding layer 130 of the first unit 100 comprises two distinct bonding portions 132 and 134 that present distinct breaking forces. Each of these bonding portions 132 and 134 is arranged between the first unit 100 and the support surface so as to make a connection between the second face 114 of the base 110 of the first unit 100 and the support surface. These two bonding portions 132 and 134 are disjoint; they extend facing distinct areas of the base 110 of the first unit 100. The term “facing distinct areas” is used to mean that the projections of the bonding portions 132 and 134 onto the base 110 in a direction normal to the second surface 114 of the base 110 are distinct and do not overlap.
The term “distinct breaking forces” is used to mean that these two bonding portions 132 and 134 are adapted to secure one of the units, specifically the first unit 100, on a support surface, and to do so while opposing given resistance to a force applied thereto.
In this example, the two bonding portions 132 and 134 are configured so as to make connections that present distinct breaking forces, i.e. so that when a given force is applied to the first unit, one of the bonding portions 132 or 134 may break while the other portion 134 or 132 remains unchanged and maintains the connection between the unit 100 and the support surface.
The different bonding portions in a single bonding layer may be made using materials and methods that are identical or different.
The bonding portions in a given bonding layer may be made integrally with the associated base. As mentioned, the figures show the invention in diagrammatic manner. Specifically, the borders (the interfaces between two bonding portions defining distinct breaking forces or inside/outside borders (in the presence of a sealed cavity)) could present a shape in section that is inclined, for example, or in the shape of a letter U turned through 90′; the width of the bonding layer may be less than the width of the base, or indeed at least one of the opposite ends of the second face 114 of the base 110 of the first unit could define a portion that does not have any adhesive material (or bonding zone/connection).
In the example shown in FIG. 1, the second unit 200 has a bonding layer 230 that is substantially uniform, presenting a breaking force that is likewise uniform.
As explained below, other embodiments are possible; the bonding layer 230 of the second unit could equally well present a plurality of bonding portions presenting distinct breaking forces.
The bonding portions 130 and 230 may be made using different methods; for example, by applying an adhesive or meltable material, by heat-sealing, by gluing, by diffusion, or by any other appropriate method.
In order to illustrate the operation of the system shown in FIG. 1, it is assumed that the bonding portion 134 adheres with a breaking force that is smaller than that needed for the bonding portion 132, and also smaller than that needed for the bonding layer 230.
Once the two units 100 and 200 have been secured to support surfaces, a user engages the retaining elements 120 and 220 so as to connect the two units 100 and 200 together. As example applications, mention may be made in particular of bags in the food industry field, or sanitary articles such as diapers.
Once the retaining elements 120 and 220 have been engaged, their connection is subjected to various stresses, as a result in particular of the way the article in question is used.
For the connection they provide, the retaining elements 120 and 220 define a strength beyond which the retaining elements 120 and 220 become separated from one another, with this strength being written F.
As mentioned above, at least one of the units 100 and 200 has a bonding layer made up of two portions defining two distinct breaking forces for the unit in question relative to the support surface.
Thus, by way of example, if it is considered that these two portions define two distinct breaking forces Fr1 and Fr2, where Fr1<Fr2, it is then possible to distinguish various particular circumstances.
In a first configuration, the forces Fr1, Fr2, and F are such that Fr1<F<Fr2.
Thus, after first closure, the system is such that on first opening the force that is applied begins by breaking one of the portions of the bonding layer (when applying a force of at least Fr1) prior to separating the units 100 and 200 (on applying a force at least equal to F).
Thus, on first use, the properties of the closure system are modified, and the breaking of one of the portions of the bonding layer creates a hinge-type structure in at least one of the units, as shown in figures that are described below.
Assuming then that the bonding portion 134 provides bonding with a breaking force (Fr1) that is less than the breaking force (Fr2) achieved by the bonding portion 132, then on first opening of the system, it is the bonding portion 134 that breaks. The portion of the base 110 that was initially secured by the bonding portion 134 on a support surface then becomes separated, forming a hinge portion.
By way of example, the bonding portion 132 may be made by heat-sealing, while the bonding portion 134 may be made by gluing. In a variant, both of the bonding portions 132 and 134 may be made by heat-sealing, with the material and methods used then defining distinct strengths, e.g. different heat-sealing temperatures, different pressures, different contact times, or indeed a combination of several of these parameters. In a variant, the two bonding portions 132 and 134 may be made by gluing, with the materials and methods used then defining distinct strengths.
The bonding layer 230 defines a breaking force greater than the force F, thereby securing the second unit 200 on a support while using the closure system. In a variant, the breaking force of the bonding layer 230 and the breaking force of the bonding portion 132 could be similar.
Such a configuration presents several advantages.
It thus makes it possible to form a closure system having properties that are asymmetrical, e.g. so that the force needed to open the closure system differs depending on the point of application. For example with such a closure system arranged on a bag, the force required for opening the bag from its inside may be different, e.g. greater, than the force required for opening the bag from its outside.
Furthermore, such a configuration makes it possible to provide a marker indicating whether the closure system has already been opened or not.
In addition, by modifying the properties of the closure system in this way on its first use, but not from the very beginning, it is possible to simplify its fabrication and integration on a product.
In a second configuration, the forces Fr1, Fr2, and F are such that Fr1<Fr2<F.
In such a configuration, on first use of the closure system, the bonding portions break in succession before the retaining elements 120 and 220 separate.
Thus, the proposed system provides a closure of the tamperproof type, which breaks on first opening.
The presence of two bonding portions 132 and 134 having distinct breaking forces makes it possible both to spread out the opening of the system, and also to propose properties that are asymmetric, e.g. so that the system presents distinct strengths as a function of the application point at which the force is applied.
FIG. 2 shows a particular embodiment of the system described above with reference to FIG. 1.
The description below relates solely to elements that distinguish the embodiment of FIG. 2 from that of FIG. 1.
In this embodiment, the bonding layer 130 of the base 110 of the first unit 100 defines an empty portion between the bonding portions 132 and 134.
More precisely, in the embodiment shown, the bonding portions 132 and 134 form strips arranged along two opposite ends of the second face 114 of the base 110 of the first unit 100, these two strips being disjoint, thereby defining a portion that does not have any adhesive material.
Thus, on breaking one of the bonding portions, the first unit 100 is held on a support surface by only one bonding strip corresponding to the bonding portion 132, thereby forming a hinge presenting greater amplitude than in the embodiment described above.
FIGS. 3 to 10 show various example applications of a closure system in an aspect of the invention.
FIGS. 3 and 4 show an example container having a closure system as described above. The container as shown is of the bag type and comprises two connected- together walls 1 and 2 defining an inside volume 3 and an opening 4, the closure system being arranged so as to close the opening 4.
In this example, the units 100 and 200 are similar to those described above with reference to FIG. 1.
Each of the two units 100 and 200 is secured to a respective wall 1 or 2 of the container via their respective bonding layers 130 and 230.
As shown in FIG. 3, one of the units, specifically the unit 100, has a bonding layer 130 presenting two bonding portions 132 and 134 that define distinct breaking forces, as described above with reference to FIG. 1.
The bonding layer 230 defines a breaking force greater than the force F, thereby ensuring that the second unit 200 is secured to a support, specifically the wall 2 of the container, while the closure system is in use.
It is assumed at this point that the bonding portion 134 defines a breaking force Fr1 and the bonding portion 132 defines a breaking force Fr2 such that Fr1<Fr2.
It is also assumed that the retaining elements 120 and 220 define a connection between the two units 100 and 200 that is configured to withstand a force F, such that Fr1<F<Fr2.
The system can be assembled on the container before or after the container is filled. By way of example, the container may be filled, and then the system may be secured thereto with its two units 100 and 200 optionally engaged, or indeed the two units 100 and 200 may be secured independently to the container, the container may be filled, and then the two units may be engaged in order to close the container.
The use of such a container is described below.
Before first opening, the two units 100 and 200 are secured respectively to the walls 1 and 2 of the container via their bonding layers 130 and 230.
Various circumstances can then be distinguished.
When the user seeks to open the container in order to access its contents, the user applies a force on the walls 1 and 2 of the container tending to move them apart so as to disengage the retaining elements 120 and 220.
This force is usually applied via the free ends of the container, i.e. the ends of the walls 1 and 2 of the container that define its opening 4. These ends may include means for facilitating user grip (not shown), e.g. striations. Thus, if the applied force is greater than the force F, the retaining elements 120 and 220 disengage, and the container is opened. Where appropriate, during disengagement of the retaining elements 120 arranged in register with the bonding portion 134, that portion breaks totally or in part.
Conversely, if a force is applied on the closure system from the inside of the container, e.g. as a result of the container being dropped through a height of one meter, then the applied force begins by breaking the bonding portion 134, thereby separating a portion of the base 110 from the wall 1, so as to form a hinge-type structure, as shown in FIG. 4. Such a hinge-type structure increases the strength of the closure system against stress exerted from the inside of the container, and consequently reduces any risk of the container opening accidentally.
Such a container thus presents greater strength against opening from the inside of the container than from its outside, while still enabling the container to be opened from the outside in simple manner.
FIGS. 5 and 6 show a variant of the embodiment described above with reference to FIGS. 3 and 4, in which each of the two units 100 and 200 is secured to a respective soleplate 140 or 240, forming supports for the units 100 and 200. These two soleplates 140 and 240 are themselves secured to the walls 1 and 2 of the container, e.g. by heat-sealing, by gluing, or by any other appropriate means.
In the embodiment shown, the soleplates 140 and 240 extend beyond the units 100 and 200, and the soleplates 140 and 240 are thus secured to the walls 1 and 2 via connections that are made on either side of the units 100 and 200, being offset away from the units 100 and 200.
Thus, while securing the soleplates 140 and 240 fitted with the units 100 and 200 on the walls 1 and 2, it is possible for example to apply pressure or heat for making these connections without damaging the units 100 and 200, and in particular the retaining elements 120 and 220.
The closure system may thus be supplied fitted with such soleplates 140 and 240 in order to facilitate assembly on a product such as a container or a sanitary article and at a high rate of assembly.
As shown in FIG. 5, one of the units, specifically the unit 100, has a bonding layer 130 presenting two bonding portions 132 and 134 that define distinct breaking forces, as described above with reference to FIG. 1.
The bonding layer 230 defines a breaking force that is greater than the force F, thus ensuring that the second unit 200 is secured to a support while the closure system is in use.
It is assumed at this point that the bonding portion 134 defines a breaking force Fr1 and the bonding portion 132 defines a breaking force Fr2, such that Fr1<Fr2.
It is also assumed that the retaining elements 120 and 220 define a connection between the two units 100 and 200 that is configured to resist a force F, such that Fr1<F<Fr2.
The soleplates 140 and 240 are secured to the walls 1 and 2 of the container in such a manner as to present strength that is strictly greater than that of the bonding layers of the units 100 and 200, and than the strength of the connection defined by the retaining elements 120 and 220, such that the soleplates 140 and 240 remain secured to the walls 1 and 2 while the system is in use.
When the system has soleplates 140 and 240 forming supports for the units 100 and 200, the system can be assembled on the container before or after filling the container. For example, it is possible to fill the container and then secure the system thereto, with its two units 100 and 200 optionally already mutually engaged, or else the two units 100 and 200 can be secured independently to the container, the container can be filled, and then the two units can be engaged so as to close the container.
There follows a description of the use of such a container.
Prior to first opening, both units 100 and 200 are secured to their respective soleplates 140 and 240 via their bonding layers 130 and 230.
Various circumstances can be distinguished.
When the user desires to open the container in order to access its content, the user applies a force to the walls 1 and 2 of the container, tending to move them apart, so as to disengage the retaining elements 120 and 220.
This force is usually applied via the free ends of the container, i.e. the ends of the walls 1 and 2 of the container that defines its opening 4. Thus, if the applied force is greater than the force F, the retaining elements 120 and 220 disengage and the container is opened. When appropriate, during disengagement of the retaining elements 120 arranged in register with the bonding portion 134, that portion breaks totally or in part.
Conversely, if the force is applied to the closure system from the inside of the container, e.g. as a result of the container dropping through a height of one meter, the applied force begins by breaking the bonding portion 132, thereby separating a portion of the base 110 from the soleplate 140 so as to form a hinge-type structure, as shown in FIG. 6. Such a hinge-type structure increases the strength of the closure system against stress exerted from the inside of the container, and consequently reduces the risk of the container opening accidentally.
Such a container thus presents greater strength against opening from the inside of the container than from its outside, while still allowing the container to be opened simply from the outside, and while presenting assembly that is simplified.
FIG. 7 shows another embodiment of a container including a closure system in an aspect of the invention.
In this embodiment as shown, the retaining elements 120 and 220 of the two units 100 and 200 are section members having complementary shapes. It will readily be understood that fields of discrete elements as shown in FIGS. 5 and 6, or of any other type of retaining element could also be used.
In this embodiment, the two units 100 and 200 are secured to the soleplates 140 and 240 via bonding strips arranged along the inside and outside edges of the bases 110 and 210 of the units 100 and 200. These bonding strips thus define an empty portion between each base and the associated soleplate, as descried above with reference to the first unit 100 shown in FIG. 2.
In the examples shown, the two bonding portions 132 and 134 connecting the first base 110 to the soleplate 140 are distinct, as described above with reference to FIG. 2. The two bonding portions 232 and 234 connecting the second base 210 to the soleplate 240 are likewise distinct, and they define distinct breaking forces, respectively Fr3 and Fr4 for the bonding portions 234 and 232, such that Fr3<F<Fr4, where F is the force needed to disengage the retaining elements 120 and 220. The forces Fr1 and Fr3 are typically identical, as are the forces Fr2 and Fr4, providing the bonding portions 132 and 134 are identical to the bonding portions 232 and 234, respectively.
It should be observed that the bonding portion 234 presenting smaller strength in this example is arranged towards the outside of the container.
Thus, when a user applies a force to open the container via the free edges of the container, this bonding portion 234 breaks, thus making it possible in particular to form a marker that the container has been opened, or indeed to increase the strength of the closure system against opening while simplifying assembly thereof, e.g. on the walls of a container or on any other product.
The bonding portion 134 breaks in the event of a force greater than Fr1 being applied from the inside of the container, thereby protecting the container against risks of accidental opening, as mentioned above.
The proposed structure thus makes it possible to form a structure having two hinges, with one of the units, the unit 100, being connected to the container via its outer border, while the other unit 200 is connected to the container by its inner border.
The empty portions formed between the bases and the soleplates may then be completely closed, so as to form sealed cavities. In the embodiment shown, it can be understood that breaking the bonding portion 134 leads to opening the sealed cavity formed between the base 110 and the soleplate 140. Likewise, breaking the bonding portion 234 leads to opening the sealed cavity formed between the base 210 and the soleplate 240.
It is then possible, by way of example, to arrange a sensory marker in such an empty portion, e.g. a marker that is visible or olfactory, and that is thus released on first use of the closure system, thereby forming an additional usage marker.
FIG. 8 shows yet another embodiment of a container including a closure system in an aspect of the invention.
In the embodiment shown, the retaining elements 120 and 220 are of the loop-and-hook type. As above, it can be understood that fields of distinct elements as shown in FIGS. 5 and 6, or of any other type of retaining element could be used, and that this particular example of retaining elements is merely illustrative.
In this embodiment, the first unit 100 is secured to the soleplate 140 via a uniform bonding layer 130 serving to hold the first unit 100 on the soleplate 140 when the system is in use.
The second unit 200 is secured to the soleplate 240 via a bonding layer 230 comprising two distinct bonding portions 232 and 234, similar to those described above with reference to FIG. 7.
The two bonding portions 232 and 234 thus define distinct breaking forces, respectively Fr3 and Fr4 for the bonding portions 234 and 232, such that Fr3<F<Fr4, where F is the force needed to disengage the retaining elements 120 and 220.
Thus, when a user applies an opening force on the container via the free borders of the container, this bonding portion 234 breaks and forms a marker indicating that the container has been opened.
It should be observed that the various embodiments described in FIGS. 1 to 8 define only two distinct bonding portions. It will readily be understood that such examples are not limiting, and that multiple bonding portions defining distinct breaking forces could be provided, providing at least one of the bonding layers of one of the units 100 and 200 includes at least two bonding portions defining distinct breaking forces.
FIG. 9 thus shows another embodiment of a container including a closure system in an aspect of the invention.
This embodiment is similar to the embodiment described above with reference to FIG. 5, and differs therefrom by the fact that the bonding layer 130 in this embodiment comprises three distinct portions, respectively 132, 134, and 136, that are adapted to secure the first unit 100 on a support while defining at least two distinct breaking forces.
Thus, it is assumed that the bonding portion 132 arranged between the bonding portions 134 and 136 defines a breaking force Fr5, the bonding portion 134 arranged along the inside edge of the unit 100 defines a breaking force Fr6, and the bonding portion 136 arranged along the outside edge of the unit 100 defines a breaking force Fr7.
By way of example, these breaking forces are configured in such a manner that Fr6<F<Fr5, and Fr7<F<Fr5.
Thus, during first use of the opening system, the bonding portion 136 breaks to form a marker that the container has been used.
The bonding portion 134 likewise serves to reduce the risk of the container opening accidentally, as described in detail above with reference to FIG. 5. By way of example, the forces Fr6 and Fr7 may be equal or they may be different.
In a variant, the breaking forces may be configured in such a manner that Fr6<Fr5<F<Fr7.
In such an embodiment, the bonding portions 134 and 132 break in succession on application of a force from the inside of the container. The bonding portion 136 serves to maintain the connection between the base 110 and the soleplate 140 with a hinge-type connection similar to that shown in FIG. 6.
The inverse configuration is possible, e.g. by configuring the breaking forces such that Fr7<Fr5<F<Fr6.
The bonding portions 136 and 132 then defines two successive markers that the system has been opened, while the bonding portion 134 serves to maintain the connection between the base 110 and the soleplate 140 with a hinge-type connection.
FIG. 10 shows another embodiment of a container including a closure system in an aspect of the invention.
In the embodiment shown, the container has an opening 4 defining a pouring spout, that can be selectively opened or closed by means of the closure system comprising the units 100 and 200 arranged on the walls 1 and 2 of the container. In this example, the two units 100 and 200 form a single continuous unit, and they are typically identical.
The presently-proposed closure system serves to ensure that the pouring spout formed in this way has improved control over its strength against opening, and to improve its strength against accidental opening, e.g. in the event of the container being dropped. The closure system as shown in FIG. 10 does not have a soleplate in this example. In a variant embodiment, the closure system could include a soleplate as described above.
The closure system presents a similar advantage when the units 100 and 200 are applied continuously all around the perimeter of the opening of a container.
In the various embodiments, the term “heat-sealing” is used for example to cover bonding by macromolecular diffusion of the type involving ultrasound, heat, or indeed ultrafrequencies.
In the various embodiments, the opening force F of the bag lies for example in the range 0.1 newtons (N) to 200 N, and more particularly in the range 0.5 N to 100 N, and still more particularly in the range 1 N to 60 N.
In the various embodiments, the base, the retaining elements, and the soleplates of the units 100 and 200 are preferably made using one (or more) polymer materials or plastics materials, e.g. linear low density polyethylene (LLDPE), low density polyethylene (LDP), metallocene polyethylene (m-PE), high density polyethylene (HDPE), ethylene vinyl acetate (EVA), and polypropylene (PP), having a molecular weight distribution that is unimodal or multimodal (e.g. bimodal), in particular a composition comprising LLPDE and a plastomer, in particular a polyethylene-based plastomer. It should be understood that the bases and/or the soleplates of the units 100 and 200 are preferably made up of a plurality of polymer materials or plastics materials, and that the various materials in the base and/or the soleplate may be distributed uniformly or non-uniformly (e.g. in the form of different layers, each having a different material recipe).
In the various embodiments, the base, the retaining elements, and the soleplate may comprise a single material or at least two materials having different melting temperatures, in particular melting temperatures that differ by at least 5° C., or more particularly melting temperatures that differ by at least 20° C. The melting temperatures of the materials forming the base, the retaining elements, and the soleplate may be different or identical and they may lie in the range 50° C. to 250° C., and more particularly in the range 60° C. to 170° C.
In the various embodiments, bonding portions defining distinct breaking forces should be understood as meaning that the breaking forces differ by at least 5%, more particularly by at least 10%, preferably by at least 20% of the weaker breaking force.
In the examples described, the bonding portions are continuous in the longitudinal direction in which the retaining elements 120 and 220 extend in their machine direction (MD), i.e. the direction in which the retaining elements are transported at the end of their fabrication, or else in the cross-direction (CD), i.e. the direction perpendicular to the machine direction, depending on the method of fabrication used. In a variant embodiment, the bonding portions may be made discontinuously in the longitudinal direction and/or in a lateral direction perpendicularly to the longitudinal direction.
FIGS. 11 and 12 are two graphs showing the effect of the system as described.
These two graphs plot the variation of the force (in newtons) as applied to two opposite walls fitted with a closure system during movement (in millimeters and plotted along the abscissa axis). FIG. 11 show the results obtained with a closure system as described above, while FIG. 12 shows the results obtained with a prior art closure system.
The measurements were taken by fastening the two units forming each of the closure systems on two support surfaces, typically walls of a container such as a plastic bag.
Those two support surfaces were then arranged in two jaws of a traction machine that applied a traction force seeking to separate the two units of the closure system, thereby simulating opening of a container fitted with such a closure system.
FIG. 11 shows two curves, representing two successive “openings” of the same closure system in an aspect of the invention.
The curve C1 thus represents the first opening of the system, and the curve C2 the second opening of the system.
The force was applied so as to simulate an opening force applied to the closure system in a “non-desired” direction, e.g. corresponding to an opening force applied from the inside of a bag, as described above with reference to FIGS. 3 and 4.
As can be seen clearly in FIG. 11, the two curves C1 and C2 present a main peak going up to a force of about 35 N.
Unlike the curve C2, the curve C1 presents a first peak of smaller amplitude (about 10 N) slightly ahead of the main peak.
The first peak corresponds to applying a force and then breaking one of the bonding portions of the closure system.
The main peak corresponds to opening the closure system after breaking one of the bonding portions of the closure system.
It can thus be seen that the closure system behaves differently on first use (curve C1) and on subsequent uses (curve C2); only the first use presents the first peak corresponding to breaking a bonding portion. FIG. 12 shows two curves D1 and D2, both representing two successive “openings” of a single closure system having retaining elements identical to those used for obtaining the graphs of FIG. 11, but fastened to the support surface in conventional manner, i.e. with a bonding layer that is uniform and configured not to break during use of the closure system.
As can be seen in this figure, the two curves D1 and D2 have similar profiles, each presenting a succession of peaks of diminishing intensity (in the range about 1 N to about 7 N) representing the progressive separation of the retaining elements until complete opening.
It can be seen firstly that unlike the curves shown in FIG. 11, the two curves D1 and D2 have similar profiles, and thus that the closure system presents properties that are substantially constant on first opening and on subsequent openings, unlike the system of the invention, which presents properties that are distinct on first opening, compared with subsequent openings.
It can also be seen that the peaks of the curves D1 and D2 are of amplitude that is considerably smaller than the amplitude of the peaks of curves C1 and C2, even though the retaining elements used are identical.
The system of the invention thus makes it possible to obtain properties of strength against opening that are greatly increased in a predetermined direction. It should also be observed that opening a system of the invention by applying a force in a “desired” direction, e.g. from the outside of a bag, would lead to curves similar to the curves D1 and D2 when using the embodiments of FIGS. 3 to 6. The system as described thus makes it possible to increase greatly the strength of the closure system against opening in the event of a force being applied in a first direction, e.g. corresponding to non-desired use of the closure system that would lead to accidental opening, while maintaining strength against opening substantially unchanged when applying a force in a second direction, e.g. corresponding to “normal” and desired use of the closure system.
The proposed closure system makes it possible to provide a closure with properties that are asymmetric, but that is easy to make and assemble on a support.
Furthermore, the proposed system is advantageous in terms of hygiene compared with conventional asymmetric closure systems; the bonding portion that is configured to break on use makes it possible in particular to avoid accumulating impurities in comparison with a system in which such a bonding portion is not present and where a hinge-type asymmetric connection is present from the beginning, thus forming a corner in which impurities can accumulate.
The system proposed is also very flexible in terms of applications, and makes it possible to provide asymmetric closure systems presenting markers of opening or indeed tamperproofing. The bonding portion configured to break during opening may for example be configured to leave residual marks (e.g. locally increased roughness, surface asperities, or surface whitening when the material is transparent) on at least one of the faces formed as a result of this bonding portion breaking, thereby forming an opening marker.

Claims

1. A closure system comprising:

a first unit comprising a base presenting first and second opposite faces, a first retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base and adapted to enable the first unit to be secured on a support surface; and

a second unit comprising a base presenting first and second opposite faces, a second retaining element arranged on the first face of the base, and a bonding layer arranged on the second face of the base and adapted to enable the second unit to be secured on a support surface;

the first and second retaining elements being configured to engage in such a manner as to make a reclosable connection;

the system being characterized in that the bonding layer of at least one of said units comprises two bonding portions, each configured to secure said units on a support surface, and presenting distinct breaking forces.

2. The system according to claim 1, wherein the bonding layer of at least one of said units includes empty portions such that the bonding portions of said at least one unit are disjoint in full or in part.

3. The system according to claim 2, wherein at least one of the empty portions defines a closed cavity, including a sensory marker.

4. The system according to claim 1, wherein each unit further comprises a soleplate forming a support surface, each base being secured to a first face of the associated soleplate by means of its bonding layer.

5. The system according to claim 4, wherein said bonding layers are made by heat-sealing said units on the soleplates.

6. The system according to claim 1, wherein:

for said at least one unit having two bonding portions presenting distinct breaking forces, the bonding portions define two distinct breaking forces Fr1 and Fr2; and

the retaining elements define an opening force F;

said forces being such that Fr1<F<Fr2.

7. The system according to claim 1, wherein each of said retaining elements is formed integrally with the associated base.

8. The system according to claim 1, wherein each of said retaining elements is formed integrally with the associated base and the associated bonding layer.

9. The system according to claim 1, wherein said retaining elements comprise fields of retaining elements, at least one of said retaining elements comprising hooks.

10. The system according to claim 1, wherein at least one of said retaining elements comprises a section member extending in a longitudinal direction.

11. The system according to claim 1, wherein the first and second units are joined, forming a single unit.

12. The system according to claim 1, wherein the bonding layer of each of said units comprises two bonding portions presenting distinct breaking forces.

13. A container having two side walls defining an opening giving access to an inside volume, said container including a closure system as defined in claim 1 arranged on its side walls so as to form a reclosable opening.

14. The container according to claim 13, wherein each unit has an internal border and an external border, the internal border being arranged in the inside volume of the container, and the external border being arranged outside of the inside volume of the container, the bonding layer of at least one of the units comprising an inner portion and an outer portion presenting distinct breaking forces, and is configured so that its inner portion presents a breaking force that is smaller than the breaking force of its outer portion.

15. The container according to claim 13, wherein each unit has an internal border and an external border, the internal border being arranged in the inside volume of the container, and the external border being arranged outside of the inside volume of the container, the bonding layer of at least one of the units comprises an inner portion and an outer portion presenting distinct breaking forces, and is configured in such a manner that its outer portion presents a breaking force that is smaller than the breaking force of its inner portion.