DESCRIPTION CLOSURE FOR CONTAINERS, IN PARTICULAR STOPPER FOR

BOTTLES OF WINE

The present invention refers in general to a closure for containers, and in particular to a stopper for bottles, which can preferably be used to stop up bottles of wine.

Although the following description is intended for bottles for food and drink, in particular bottles for wine, it is clear that the teachings of the present invention can be applied equally effectively to containers of any type of substance

(food or otherwise) that require sealed stoppers suitable on the one hand for preventing the substance contained in it from leaking out, and on the other hand for preventing gas and/or foreign substances (also deriving from the material from which the closure is made) from entering inside the container. In the field of stoppers for bottles of wine, the most common material from which they are made is cork: such a material is expensive and increasingly rare, given that it comes from very specific plants, thus having relatively limited availability in nature.

Moreover, cork stoppers have many problems from the functional point of view: such stoppers often damage the wine contained in the bottles, giving it a taste that is no longer the original one and that is always unpleasant to the palate . When the wine contained in the bottles is valuable, the presence of a defective stopper involves substantial waste and costs.

Even when cork stoppers do not have defects, it is advisable to replace them periodically (10-15 years) , to avoid spoiling the content of the bottles.

Cork also creates problems in installing and removing it from bottles: indeed, automatic stoppering machines are subject to exposure to dust and pieces of cork that detach, polluting the environment and compromising the quality of the process; moreover,_ cork is a non-uniform material, for which reason it behaves differently in each application according to the supply batches; finally, when the stopper is removed from the bottle, for example through a common corkscrew, small pieces of cork may fall inside the bottle and pollute its content. Stoppers for bottles made from plastic material

that provide performance equivalent to or better than that of cork stoppers without the aforementioned problems are already on the market, even if these stoppers are often subject to criticism.

A problem encountered in the case of stoppers made from synthetic material is the loss of seal that occurs with the passing of time. This phenomenon is due to the fact the plastic material, subjected to pressure against the walls of the neck of the bottle, tends to stretch in the longitudinal direction of the stopper and thus to narrow its diameter. Consequently, the sealing pressure reduces and the content may leak. This problem has already been solved by a stopper as outlined and claimed in European patent

-EP .I 1.6:9__2.3;4._B1% Such a patent describes a closure made from elastomeric material comprising on the inside a frame made from rigid plastic material . Such a frame consists of a central shaft that connects small discs on top and below, with the function of supporting the surrounding elastomeric material. In practice, the presence of the small discs allows the longitudinal extension of the elastomeric material subject to radial pressure to

be contained and therefore allows a long-lasting good seal to be ensured.

However, such a stopper also has a defect. Indeed, it is known that the openings of bottles can have substantial tolerances, with the consequence that the internal diameter of the neck can vary even by 5-10 tenths of a millimetre more or less than the standard measurement. Moreover, the customs of the various countries can be to adopt different measurements to those dictated by EC norms for the necks of bottles; for example in Italy there can be differences even greater than those indicated above.

It is thus clear that, to always ensure a good seal despite the substantial variability in size of the neck of the bottle, a stopper must have sufficient elasticity to compensate for the aforementioned d,i fferences from bottle to bottle- Cork stoppers or ones made from full elastomeric material satisfy this requirement, whereas stoppers with a frame have a lower elasticity due to the presence of the rigid material embedded in the elastomer. These last stoppers, therefore, to offer their best performance must be used on necks of bottles with a certain uniformity of size. The purpose of the present invention is to

solve _the aforementioned problems of the prior art, providing a closure made from plastic material for containers, in particular for bottles of wine, which has optimal sealing characteristics that last through time and at the same time is- adaptable to necks of bottles of variable sizes.

Such a problem is solved by means of a closure for containers like the one outlined in the attached claims . The present invention shall be better described by some preferred embodiments, provided as a non- limiting example, with reference to the attached drawings, in which:

Figure 1 is a perspective section view of a first embodiment of a closure for containers according to the present invention;

Figure 2 is a perspective view of the detail of the frame of the closure of figure 1;

Figure 3 is a perspective view of the frame according to a second embodiment of the invention;

Figure 4 is a perspective view of the frame according to a third embodiment of the

invention;

Figure 5 is a side view of the frame according to a fourth embodiment of the invention; - Figure 6 is an exploded perspective view of the frame- of figure 5;

Figure 7 is an exploded perspective view o'f the frame according to a fifth embodiment of the invention; - Figure 8 is a side section view of a sixth embodiment of the closure of the invention;

Figure 9 is a perspective view of the frame of the closure of figure 8; - Figure 10 is a side section view of a seventh embodiment of the closure of the invention;

Figure 11 is a perspective view del frame of the closure of figure 10; - Figure 12 is a side section view of an eighth embodiment of the closure of the invention;

Figure 13 is a perspective view of the closure of figure 12; - Figure 14 is a perspective view of the

frame of the closure of figure 12;

Figure 15 is a side section view of a ninth embodiment of the closure of the invention; - Figure 16 is a perspective view of the frame of the cl-osure of figure 15;

Figure 17 is a side section view of a tenth embodiment of the closure of the invention; - Figure 18 is a perspective view of the frame of the closure of figure 17. With reference to the figures, hereafter the closure for containers according to the invention shall be described, wholly indicated with reference numeral 1.

The closure 1 comprises a body 2, substantially cylindrical and tapered at the end portions 3 , -4. The tapering can for example have a rounded profile, like in' figure 1, -and has the function of making it easier to insert the closure l into the neck of the container .

The body 2 of the closure 1 is made from plastic material, preferably an expanded thermoplastic elastomer. Although it is possible to use a vast range of elastomers, preferably said

expanded thermoplastic elastomer is selected from block copolymers like styrene-butadiene-styrene

(SBS) , styrene-isoprehe-styrene (SIS) , εtyrene- ethylene-butylene-styrene (SEBS) , styrene-ethylene- propylene-styrene (SEPS and SEEPS) .

The expanding agent can be of the chemical type (for example, azodicarbonamide) or more preferably of the physical type (for example, CO ₂ , nitrogen, air, fluorinated hydrocarbons, etc.). More preferably, the expanding agent shall be a fluid- in supercritical phase, with nitrogen in supercritical phase being particularly preferred.

The method used for the preparation of the stopper shall preferably be injection moulding of thermoplastic material, in the presence of an expanding agent, inside a suitably shaped mould, as well known to the man skilled in the art .

According to a particularly preferred embodiment, the body 2 shall have a surface layer of non-expanded material. In this way, it is possible to combine a greater surface rigidity with the flexibility typical of the expanded material present on the inside. A method that can be used for the preparation of such a stopper foresees injecting a first portion of thermoplastic material without

expanding agent into the mould and adding the expanding agent to the flow of the remaining thermoplastic material subsequently injected, as described for example in published international application WO 00/54952.

The closure 1 also comprises, a frame 5 made from a more rigid plastic material (for example, PP) embedded in the body 2 made from expanded material . Said frame 5 comprises flexible support means 6 suitable for containing the longitudinal extension of the elastomeric material of the body 2 and for flexing when the body of the closure is subjected to a radial stress, like when the closure 1 is inserted into the neck of a container. Such effects are not obtained because of the particular properties of the material, which as stated is a rigid plastic, but thanks to the special structure of the frame.

In the embodiment of figure 2, the frame 5 is made up of two end rings 7, V connected by flexible support • means 6 consisting of two crossing helical elements 8, 8', which wind one in the clockwise direction the other in the anticlockwise direction. The thickness of such helical elements can vary, without for this reason modifying the structure of the frame.

As shown in figure 1, after the injection of the elastomeric material the frame 5 is substantially embedded in it, excluding the end rings 7, 7' that stick out at the two ends of the closure 1.

In the embodiment of figure 3, the two end rings 7, 7' are connected by three helical elements 9, 9', 9", which start at different points of said end rings 7, 7' and that all wind in the same direction (clockwise or anticlockwise) .

The embodiment of figure 4, on the other hand, has the two end rings 7, 7' connected again by three helical elements 10, 10' , 10" like in the embodiment of figure 3, but with a smaller number of turns. A reinforcing ring 11 is also arranged in intermediate position between the end rings 7, 7' and acts as a joint between the bottom portion and the top portion of the helical elements 10, 10', 10".

According to the embodiment shown in figures 5 and 6, the frame 5 is made up of two half-frames 12, 12' coupled together. Each half-frame 12, 12' is made up of a top semicircular element 14, 14a and a bottom semicircular element 14', 14a', joined by stave elements 15. Each of such semi-circular elements 14, 14', 14a, 14a' comprises interlocking

means 16, 16' matching the interlocking means present on the half-frame with which they are intended to couple. On the half-frame 12, such interlocking means consist, in the example shown in the figures, of a small tooth 16 and a blind hole 16', which shall couple with a corresponding blind hole 16' and small tooth 16 present on the half- frame 12', but in inverted position. Preferably, the small tooth 16 and the blind hole 16' are arranged on the top semicircular element 14 in inverted position with respect to the bottom semicircular element 14' of the same half-frame.

The frame 5 thus formed after assembly comprises a top ring 13 and a bottom ring 13' joined by barrel-shaped flexible support means 6, comprising said stave elements 15. The stave elements .15 are-separated by notches 20 in order to increase their radial deformability.

The top ring 13 and the bottom ring 13' project with respect to the flexible support means 6, so as to contribute to the axial containment action of the expanded elastomeric material .

The embodiment shown in figure 7 is similar to that of figures 5 and 6, from which it differs in that it has less stave elements 15.

The closure 1 shown in figures 8 and 9 has a substantially cylindrical body 2 with rounded end portions 3 , 4.

The frame 5 is made in a single piece and comprises barrel-shaped flexible support means 6 that consist of a plurality of stave elements 15 that join a top ring 17 and a bottom ring 17' with edges projecting outwards.

The closure 1 of figures 10 and 11 has a barrel-shaped body 2 in which the frame 5 is embedded, the latter, like in the previous embodiment, consisting of flexible support means 6

(stave elements 15) that connect a top ring 17 and a bottom ring 17' with edges projecting outwards. The notches 20 extend at the top and bottom on the top and bottom rings 17 and 17' , respectively, almost up to the—edge, so as to maximize the flexibility of the stave elements 15.

The closure 1 shown in figures 12, 13 and 14 comprises a substantially cylindrical body 2 with rounded end portions 3 , 4 and a frame 5 embedded in it.

The flexible support means 6 of the frame 5 comprise a plurality of stave elements 15 joined to each other by connection portions 18 arranged in

intermediate position with respect to the ends of said stave elements 15 and such as to create, between a stave element 15 and the contiguous element, some notches 20. The top and bottom ends of each stave element 15 face towards the outside to form the edges 19, 19' that, as a whole, form segmented rings 21, 21' , respectively. Such a configuration allows the maximum flexibility at the ends of the closure 1. The closure 1 shown in figures 15 and 16 comprises a substantially cylindrical body 2 with rounded end portions 3 , 4 and a frame 5 embedded in it.

The flexible support means 6 of the frame 5 comprise a tubular body 21, comprising on the inside some reinforcing ribs 21a. The tubular body 21 is interrupted by notches 22., .22.' extending longitudinally, starting from the two ends of the tubular body 21, for a length greater than half the height of the tubular body 21. Such notches 22 are open between substantially parallel sides 22a, joined by a base portion 22b with rounded cusp. The notches 22 that extend from a first end are staggered with respect to the notches 22' originating from the other end. In this way an

overall . flexibility of the flexible means 6 is obtained distributed over the entire tubular body 21, without however structurally weakening the frame 5. Such a shape also allows deformations to be reduced during fitting. The base portion 22b of the notches 22 shaped like a rounded cusp allows a more homogeneous distribution of the tensions to which the frame is subjected during fitting.

At the two ends, the tubular body 2-1 ends with respective rings 23, 23' projecting outwards with respect to the tubular body 21 and having a weakened portion at the notches 22, 22' to form connection stems 24.

The closure 1 shown in figures 17 and 18 comprises a substantially cylindrical body 2, slightly rounded at the central portion and tapered towards the outside "at"the -endsv .having rounded end. portions 3, 4 and a frame 5 embedded in it.

The flexible support means -6 of the frame 5 comprise a plurality of. stave elements 25, 25' joined to each other by connection portions 28 and interrupted by notches 29, 29' that extend longitudinally up to said connection portions 28. The stave elements 25 that project towards a first end of the frame 5 are staggered with respect to the

corresponding stave elements 25' extending towards the opposite end. This embodiment, like the previous embodiment, also allows an overall flexibility of the flexible means 6 to be obtained distributed over the entire body of the frame 5, without however structurally weakening it. The maximum flexibility is also obtained at- the ends of the closure 1.

The top and bottom ends of each stave element 25, 25' face outwards to form edges 30, 30' . From such edges 30, 30' extend teeth 31, 31' that make the elastomeric material grip better to the frame 5, said teeth 31, 31' going upwards and downwards, respectively.

The closures 1 according to the invention can be obtained by injection moulding. The frame 5 shall be positioned in advance inside the mould, in which the thermoplastic material- mixed -with the expanding agent shall then be injected, filling all of the empty spaces- of the mould and solidifying with the frame.

In all of the cases shown, the top and bottom ends of the frame 5 stick out from the body 2 of the closure -I ₁ but it shall be possible to make closures in which the frame is completely embedded in the body 2 made from expanded material or in which just

one end of the frame.- 5 sticks out.

The. methods and the apparatuses used to produce closures 1 according to the invention are totally conventional and therefore shall not be described in any greater detail .

From what has been described above, the advantages of the closure l- according to the invention are immediately clear.

The frame 5 carries out the function of a support for the expanded elastomeric material, preventing it from stretching in the longitudinal direction caused by the continued pressure exerted by the neck of the container on the material itself. Such an effect is obtained both in the embodiments of figures 1 to 4 - thanks to the helical elements that form spirals and anchor the expanded material .preventing .its longitudinal dislocation — and in the embodiments of figures 5 to 18, in which the barrel- shaped flexible support means, in cooperation with top and bottom rings or discs, carry out the same containment function. At the same time, unlike the solution of the state of the art described previously, the radial flexibility of the support means 6 avoids the rigidification of the body 2 of the closure and allows a substantial

compressibility, so that the closure can easily adapt to the variability in size of the neck of the bottles. ^"

The fact that the frame 5 is embedded in the expanded elastomeric material is of substantial importance. Indeed, the elasticity of the elastomeric material is in no way blocked- by the flexible support means in the entire thickness of the closure and can therefore display both the characteristics of compressibility and of elastic return possessed by such materials. The optimal sealing pressure against the walls of the neck of the container is therefore exerted in all conditions . The frame with barrel-shaped flexible support means 6 (figures 5 to 14) has the further advantage of decreasing the amount of expanded material necessary, with a consequent decrease in production costs. As is clear to a man skilled in the art from the descriptions made previously of some preferred embodiments of the invention, what has been illustrated and described must obviously be considered a non-limiting example of the field of protection of the present invention as defined by

Ib

the attached claims .

For example, to make inscriptions, drawings or captions on the surface of the closure 1 according to the invention it is possible to use, alongside normal ink printing techniques, methods based upon the use of a laser. The type of laser and the energy- necessary for such a marking process shall depend upon the plastic material to be marked. For the material used in the closures of the present invention it shall in general be preferable to use an NdYAG laser, having a power of 30 to 200 Watt and a wavelength of 1064 nm (secondary waves 532-355-266 nm) . The plastic material of which the stopper consists must be added to with a colour-changing master -that is able to change colour when hit by the ray of the laser. A preferred master is Clariant's SARMATENE ^® . The colour-changing master is added in an amount of between 1% and 4%, preferably about 2%. The selection of a laser marking method that foresees the use of a colour-changing, master, instead of laser processes that foresee carrying out the inscription by surface carbonisation, is fundamental. Indeed, in the case of a closure for containers, in which the seal itself is essential, an inscription obtained through surface carbonation

irremediably leads to unacceptable irregularity of the surface. Such surface irregularity would therefore not allow the necessary adherence to the inner surface of the neck of the container to ensure the seal of the closure.

The apparatuses for carrying out the marking process are of the known type and are commercially available, and therefore shall not be described in_ any greater detail .