Container for fluid product

Description

TECHNICAL FIELD

The invention refers to the general field of containers, in particular, but not exclusively, to single-use containers, also called “single-dose” recipients or dispensers, designed to store and dispense the product which they contain, said product being fluid, i.e. powdery or liquid to pasty, with a dynamic viscosity typically ranging between 10⁻³ Pa·s and 10² Pa·s at 20° C.

BACKGROUND OF RELATED ART

The majority of known single-dose dispensers have a generally cylindrical body which defines a chamber designed to receive the fluid product to be dispensed. So, the single-dose dispenser described in FR 2 826 245 is closed at one end by a piston able to slide inside said cylinder, and at the other end by a cap that can be turned in relation to the cylinder, between an open position and a closed position. Using this approach, where the product, which is viscous and sensitive to oxidation by the ambient air, is extracted with a piston, expensive containers are developed, mainly aimed at the cosmetic market.

Using another method, suitable for less viscous products such as liquids, in particular drinks, the single-dose dispenser comprises, as in that described in U.S. Pat. No. 3,739,827, a cylindrical body closed at one end by a flat bottom, with a fairly thin cylindrical side wall, optionally protected by a shell which covers the bottom and the side wall. Towards the other end of said side wall the body has a thicker ring-shaped portion which, like the open end of a glass, acts as a support for the mouth of the container. The top part of said thick ring-shaped portion may, in addition to serving as a mouth, also act as a sealing surface on which a lid or any other type of “tear-off” type closure can be stuck or heat sealed.

In a slightly different approach, suitable for less liquid products, in particular for food products, request US2005/0077297 describes a body that can easily be made by blowing extrusion, with a thin, cylindrical or prismatic wall and a flat bottom but no thick ring-shaped portion. The cover is sealed on a radial edge worked into the end of the cylindrical wall which is opposite the flat bottom. The radial edge has a radial excrescence shaped like a tab used as means of gripping and on which the sealing force is weaker, which makes it possible to easily remove the lid using said tab.

Each of these containers, which are more or less expensive to produce, fulfills a particular role, specific to the product which it is designed to contain. The applicant sought to develop a container, in particular, but not exclusively, a single-dose dispenser, suitable for a great number of fluid, liquid or highly is viscous products, also including products in powder form, which would allow the product contained in said container to be dispensed quickly and completely and which would very easy and very cheap to produce.

European patent application EPA151934 discloses flexible tubes having a head including a top wall having a dispensing opening of small diameter closed by a pin mounted on a pivoting cap, the cap being hingedly attached to the peripheral side of the top wall. In order to improve the restitution rote of such tubes, particularly mediocre given the rigidity of the tube head, it is suggested to provide on the top wall an annular tear zone allowing to remove the top wall, when the tube is almost empty. By removing the top wall, the user may access the product remaining in the tube, and which is otherwise trapped between the peripheral area of the head and the dispensing opening.

DESCRIPTION OF THE INVENTION

A first object of the invention is to provide a container comprising a flexible body with a side wall globally directed along a longitudinal axis, and a ring-shaped top part which has a dispensing opening at a first end and which, at a second end, is adjacent to the side wall of the flexible body. The ring-shaped top part is stiffer than the flexible body. The container has the following structural features:

a) the dispensing opening has a surface which accounts for at least 60% of the envelope area of the ring-shaped top part at the level of the first end; “envelope area” refers to the area of the surface bound by the external contour of the ring-shaped top part at the level of the first end, the external contour being defined by the intersection of a plane perpendicular to the longitudinal axis and the external surface of the ring-shaped top part;
b) the ring-shaped top port has a cylindrical or prismatic outer surface;
c) the side wall of the flexible body, adjacent at a first end to the second end of the ring-shaped top part is the continuation of the outer surface of the ring-shaped top part;
d) the side wall has a second closed end, whose flattened shape results from joining the facing parts of the inner surface of a cylindrical sleeve whose section was initially that of the first end of the side wall.

The container according to the invention comprises a flexible body with a side wall globally directed along a longitudinal axis (A). Said side wall in general has a greater dimension along said longitudinal axis. Preferably, it is symmetrical in relation to a plane passing through said axis (A) and the direction of the second flattened closed end. Preferably also, axis (A) is an axis of symmetry (rotational symmetry or n-order symmetry around an axis, n being an integer equal to or greater than 2) of the ring-shaped top part.

The ring-shaped top port has a first end which surrounds a large dispensing opening. It has a second end, adjacent to the first end of said side wall of the flexible body. It has a cylindrical or prismatic outer surface, the n facets of the prism respecting an n-order axial symmetry, typically along the longitudinal axis (A), and the n angles of the dihedra being preferably rounded. For esthetic and practical reasons (size, ease of gripping), the side wall of the flexible body is flush with the ring-shaped part. In other words, said side wall of the flexible body is a continuation of the outer surface of said ring-shaped top part: the outside contour of the section of the first end of the side wall substantially coincides with the outside contour of the section of the second end of the ring-shaped top part. Preferably, the ring-shaped top part is toric in shape, having rotational symmetry around axis (A).

To make it easier to dispense the product contained in the container quickly and completely, the ring-shaped top part has at its first end a dispensing opening whose surface accounts for typically at least 60%, and preferably at least 70%, of the section—through a plane perpendicular to that of axis (A)—of the external contour of said ring-shaped top part at the level of said first end. Typically, with the usual geometries under consideration for such containers, the opening has a diameter greater than 10 mm, preferably greater than 15 mm, preferably still greater than 19 mm. Advantageously, the ring-shaped top part has, at the level of the first end, a top wall free of any excrescence such as a tab or a pivoting cap, so that the ring-shaped top part (20) has an easy to access rim surrounding the dispensing opening. Preferably, the top wall is free of any ruggedness, such as a burr caused by removing a tear zone provided on the top wall, so that the ring-shaped top part (20) has an easy to access rim surrounding the dispensing opening.

In this way, the first end of the ring-shaped top part appears as a mouth similar to that of a glass, which means that the container can be used as glass to drink the product which it contains, or to swallow it if it is a powder.

The ring-shaped top part is stiffer than the side wall of the flexible body: its stiffness, provided by its thickness and/or the mechanical properties of the material(s) that it is made from, is sufficient for said container to be gripped with one's fingers placed either on ring-shaped top part or on the side wall of the flexible body close to the ring-shaped top part, without crushing said flexible body, i.e. without suddenly decreasing the internal volume of said flexible body. The height of said ring-shaped part may also contribute to the rigidity of the container and ease of grip, without however being critical. Indeed, the height of the ring-shaped top part may be small, as long as it is sufficient to allow gripping of the flexible body at the level of or close to the ring-shaped top part.

According to the invention, the flexible body is primarily made up of the side wall, the bottom being replaced by what is commonly called a transverse or final weld, said weld resulting from joining the facing parts of the inner surface of a cylindrical sleeve whose section was initially that of the first end of said side wall, which also coincides, in a preferred method, with the outer shape of the second end of the ring-shaped top part.

In other words, the container according to the invention has a top part similar to the top part of glass or a mug, easy to hold; and a bottom part similar to the skirt of a flexible tube which, under the pressure exerted by the fingers and the palm of the hand, can be crushed and be made to collapse so that the product contained inside said skirt can be pushed out. The ring-shaped top part makes it possible to hold the container properly and to handle it safely even if it contains liquid products that spill easily. The bottom part is easy to make and, by its flexibility, it makes it possible to easily push out the products contained in the container by means of a familiar movement, even if these products are strongly viscous.

Admittedly, the part of the skirt located in the vicinity of the ring-shaped top part cannot be completely collapsed, because of the very proximity of said ring-shaped top part which is stiffer. However, even with very viscous products, complete emptying of the container is possible because of the high degree of accessibility provided by the width of the dispensing opening: a cosmetic cream, for example, which might have remained on the internal wall of the skirt despite the various manipulations of the skirt, could still be removed on the end of a finger via the opening of the container, as long as the diameter of the latter is greater than 15 mm or 19 mm.

A side wall in the form of a flexible skirt has many other advantages. It is a structural element that is easy and inexpensive to produce. It can be made using existing installations designed for manufacturing flexible plastic tubes. All that needs to be done is to replace the tube head, in general a neck surrounding a dispensing opening and connected to the skirt by a substantially truncated shoulder, by said ring-shaped top part. The side wall can be made as a flexible tube skirt, having a thickness typically between 200 μm and 600 μm. However, according to a process different from that typically used for making flexible tube skirts, it is possible to make containers having a much thinner body, having a thickness such as that of plastic bags and sachets, namely a thickness between 40 and 200 μm, preferably around 70 μm.

The side wall can include one or more plastic layers, preferably thermoplastic, and possibly, one or more metallic layers.

The side wall can be made by making a transverse weld on one end of a substantially cylindrical sleeve which itself can be obtained either by extrusion or by rolling and welding a flat film. In this latter case, the scope for decoration is greatly increased, because all known techniques for fixing decoration to flat film (offset printing, flexogrophy, silk-screen printing, inkjet, gilding and hot marking) can be applied, whereas the techniques for fixing decoration to cylindrical or prismatic side walls are limited, more difficult to apply, and therefore more expensive. Obviously, other techniques for fixing decoration can also be used, for example applying a label to the side wall and/or outer surface of the ring-shaped top part. In particular, when the containers can be obtained by one-piece molding of the ring-shaped top part and the sleeve destined to become the side wall after transverse welding of its end, in-mold labeling can be performed, i.e. a label placed in the mold beforehand. The container can be provided with a lid fixed for example by clipping or by screwing onto the ring-shaped top part, the means of fixing (clipping rib or screw thread) being placed preferably on a cylindrical wall of the ring-shaped top part, typically the outer wall or the inner wall surrounding the opening. But, in particular when a single dose container is involved, a less expensive solution is to fix a cover on the top wall of the ring-shaped top part, typically by gluing or heat sealing. Advantageously, the cover has a radial excrescence in the shape of a tab used as means of gripping. Advantageously, the cover comprises materials similar, and preferably identical, to those of the side wall of the flexible body and to those of the ring-shaped top part: the homogeneity of materials used makes packaging recycling easier.

There are several possible methods for making such containers and these methods correspond to those used to produce flexible tubes: first, a container blank is made, including the ring-shaped top part and the sleeve destined to become the side wall after transverse welding of the end that is not adjacent to the ring-shaped top part. The dispensing opening is plugged, for example by a cover heat-sealed to the top wall of the ring-shaped top part. The container is filled by pouring in the product which it is to contain through the still-open end of the sleeve. Finally the transverse weld is made. In general, heating grips are used to collapse and to weld the end of the sleeve that has been swept with hot air beforehand. Welding can also be carried out by induction when the sleeve is mode of metaloplastic material. This welding can also be done by ultrasounds or using a laser.

To manufacture the container blank, the ring-shaped top part and the sleeve can be made separately, then the one fixed to the other by welding, gluing or any other means. The ring-shaped top part can also be over-molded, by injection or compression, onto one end of the sleeve. The sleeve itself can be obtained by extrusion or rolling-welding of a web. Particularly when dimensions are small, the length of the side wall is not too large compared to the largest dimension of the section, and/or the part to be made is not too thin, it is also possible to make the “upper ring-shaped part+sleeve” assembly by one-piece molding, or by making two consecutive moldings of the flexible body and then of the ring-shaped top part. In this latter case, the flexible body and the ring-shaped top part can be made up of two different, but compatible, molten thermoplastic materials.

Once the transverse weld has been made, the product can be properly isolated from the surrounding environment provided that the transverse wall of the flexible body, the ring-shaped top part and the cover act as a barrier protecting either the product from the surrounding environment (to prevent losses of perfume, damage by oxidation, UV radiation, presence of moisture, etc.) or the surrounding environment from the product. Such a container may, like flexible tubes, be perfectly suited to the conditioning of products likely to be damaged during storage by a possible attack from the surrounding medium.

For example, to ensure proper leak-tightness from the diffusion of gases and flavors, the side wall and the lid may be made from multi-layer films containing a layer acting as a barrier to gases and flavors, such as a metal layer or a layer made from EVOH (ethylene vinyl alcohol polymer) and the ring-shaped top part may be obtained by co-injection of various plastics, with a thermoplastic layer acting as a barrier to the diffusion of gases and flavors, typically a layer made of EVOH. The latter, as it is sensitive to moisture, can to advantage be sandwiched between two support layers, typically made from polyethylene or polypropylene.

Leak-tightness can also be achieved by in-mold labeling of the container blank: The ring-shaped top part and the sleeve destined to become the side wall after transverse welding of its end are molded in one piece, by injecting thermoplastic into the molding cavity into which has previously been placed a label including a layer acting as a barrier to diffusion and placed so that it entirely covers the outer surface of said container. The top wall of the ring-shaped top part is then sealed by a lid made from a film containing a barrier layer.

Another subject according to the invention is to provide a container blank comprising a cylindrical or prismatic sleeve, globally directed along a longitudinal axis and a ring-shaped top part has a dispensing opening at a first end and which, at a second end, is adjacent to the sleeve. The ring-shaped top part is stiffer than the sleeve. The container blank has the following combination of features:

• • a) the dispensing opening has an area which accounts for at least 60% of the envelope area of the ring-shaped top part (20) at the level of the first end;
  • b) the ring-shaped top part has a cylindrical or prismatic outer surface;
  • c) the sleeve of the flexible body, adjacent at a first end to the second end of the ring-shaped top part, is the continuation of the outer surface of the ring-shaped top part;
  • d) the sleeve has a second end which is open.

Said container blank has a cylindrical sleeve, which may comprise, like a flexible tube skirt, one or more plastic layers and optionally one or more metallic layers. Said cylindrical sleeve may have a thickness between 200 and 600 μm but it may also be thinner, with a thickness of typically between 40 and 200 μm, if the manufacturing process is different from that typically used for making flexible tubes.

ADVANTAGES

The container, designed mainly to contain liquids, is also suitable for containing solid products such as powders, crystals, tablets, etc. It is very easy to use, quick and easy to open, and dispenses the product contained quickly and completely thanks to the crushable side wall of the flexible body.

Because it uses the minimum amount of raw materials, its impact on the environment is kept to a minimum. In particular, when the materials used are all plastic, complete recycling can be carried out by crushing and re-using in the plastics industry. In certain configurations, it provides integral barrier properties.

It is an industrial product, involving the use of productive industrial processes, both for manufacturing and for filling it, these processes having already proven reliable for the manufacture of flexible tubes.

It is a type of packaging which covers a great number of application fields, because of the variety of materials which may be used, the many shapes it can take and its ability to contain solid, powdery, pasty or liquid products. It provides a cheap alternative to existing but less universal types of packaging, such as flexible pouches, aluminum tubes or gloss ampoules.

It is particularly suitable for the following applications:

• • Cosmetics: single doses of bath salts, single doses for body core, doses for hair coloring, etc;
  • Perfumery: refills;
  • Industry: doses of motor oil, for example doses of 2-stroke fuel mixtures, doses of coloring for paints, etc;
  • Food: single doses of sauce for seasoning, single doses of liquid cream, doses for cereals, spirits, sorbets and ice creams, for soups, etc;
  • Pharmacy: single doses for liquid products, of the ampoule type;

It may have the conventional dimensions of a flexible tube and may therefore have a capacity typically ranging between a few tens of milliliters and 500 milliliters.

For conditioners, it is very quick to fill on existing lines that are also used to fill flexible tubes.

For distributors, it is easy to shelf and can, because of the range of printing is techniques available, present the product which it contains in a particularly favorable light.

FIGURES

FIG. 1 is a perspective view of a first container according to the invention after use.

FIG. 2 is a perspective view of the container in FIG. 1 before use.

FIG. 3 is a perspective view of a container blank before sealing a lid.

FIGS. 4 and 5 are cross sectional views of ring-shaped top parts of two other containers according to the invention.

EXAMPLE 1

FIGS. 1 to 3

The invention is illustrated by a container 10 including a flexible body 30 with a side wall 35 globally directed along a longitudinal axis (A), and a ring-shaped top port 20 adjacent to the side wall 35 of the flexible body 30. The ring-shaped top part 20 has, at one end 21, a wide dispensing opening 25. It is called “top part”, because, by analogy with the convention used to present flexible tubes, and unlike the illustration in FIGS. 1 to 3, the container is regarded as being presented vertically, the dispensing opening pointing upwards and the transverse weld pointing downwards.

The ring-shaped top part 20 appears as a high density polyethylene (HDPE) ring, of elliptical section, the ellipse having as its large diameter 25 mm and as its small diameter 19 mm. The ring-shaped top part is quite thick (approximately 2 millimeters). The flexible body 30, 70 mm in height, is primarily made up of the side wall 35, also made of HDPE and is 400 μm thick. Because of the difference in thickness, the ring-shaped top part 20 is considerably stiffer than the flexible body 30.

The side wall 35 is shaped like a flexible tube skirt, i.e. it has a first elliptical end 36 adjacent to the second end 22 of the ring-shaped top part 20 and a second closed end 37, whose flattened shape results from joining the facing parts of the inner surface of a cylindrical sleeve 35′ whose section is an ellipse corresponding to the shape of the first end 36. The outer surface 23 of the ring-shaped top part 20 is the continuation of the side wall 35 of the flexible body 30.

To make it easier to dispense the product contained in the container quickly and completely, the ring-shaped top part 20 has at its second end a dispensing opening 25 whose surface accounts for 74% of the section—through a plane perpendicular to said axis (A)—of the ring-shaped top part 20 at the level of the first end 21. Advantageously, said ring-shaped top part 20 has, at the level of said first end 21, a top wall 26 that can act as a mouth 27. In this way, the first end 21 of the ring-shaped top part 20 appears as a mouth similar to that of a gloss.

The height of the ring-shaped top part 20 is about 15 mm so that it is easy to grip said flexible body with one's fingers.

The flexible body 30 is primarily made up of the side wall 35, the bottom being replaced by the transverse weld 39, said transverse weld 39 resulting from joining the facing parts of the inner surface of the cylindrical sleeve 35′ whose section is that of the first end 36 of the side wall 35, which also coincides with the external shape of the second end 22 of the ring-shaped top part 20.

It is closed by a lid 40 that is heat sealed to the top wall 26 of the ring-shaped top part 20. Lid 40 has a radial excrescence 41 in the shape of a tab used as a means of gripping.

In this example, the container is a single-dose cosmetic dispenser. The container blank 10′ was made by IML: the ring-shaped top port 20 and sleeve 35′ destined to become the side wall 35 after transverse welding of the second end 37 are molded as a single piece. High density polyethylene was injected into the molding cavity into which a label (not shown) had previously been placed; this label is printed using the four-color process and includes a layer made of aluminum alloy forming a perfect barrier against diffusion. The label was placed in the molding cavity using the process described in French potent application no 07 07537, registered on 10 Oct. 2007. Once the blank has been molded, said label completely covers the outer surface of the ring-shaped top part 20 and sleeve 35′. The top wall 26 of the ring-shaped top part 20 is then sealed by a lid 40 made from a film also containing a barrier layer mode of aluminum alloy.

EXAMPLES 2 AND 3

FIGS. 4 and 5

FIGS. 4 and 5 are cross sectional views of ring-shaped top parts of two other containers 10′, 10″ according to the invention.

The ring-shaped top parts 20′ and 20″ have the shape of a HDPE ring having a circular cross-section and a 19 mm external diameter. The side walls 35′ and 35″ of the flexible bodies 30′ and 30″ are made of LDPE and have a thickness of 400 μm.

The ring-shaped top part 20′ of container 10′ (FIG. 4) is quite thick and high: its thickness is of 2 mm and its height is of 6.4 mm. Such a ring-shaped top part 20′ is light (approximately 0.5 g) and has an important stiffness with respect to the body of the container, which allows for an easy and safe gripping of the container. Such a ring-shaped top part 20 is particularly suitable for containers storing liquids, particularly drinks.

The ring-shaped top part 20″ of container 10″ (FIG. 5) is less thick and less high than the ring-shaped top part 20′ of container 10′: its thickness is of 1.2 mm, except at the level of the dispensing opening, where it is 2 mm-thick, and its height is of 3.2 mm. Such a ring-shaped top part 20″ is light (approximately 0.15 g) and therefore low-cost. Its stiffness is sufficient with respect to the body of the container to allow a safe gripping of the container.