[0001] The present invention relates to a synthetic stopper for glass bottles.
[0002] In particular, the invention relates to a synthetic stopper in a semi-expanded foam
material for glass bottles of any shape whatsoever.
[0003] The problem of replacing cork with other materials for plugging glass bottles that
has been under research for some time in an attempt to eliminate the "corked taste"
that can plague even best quality wines, has become far more urgent recently due to
the increasing depletion of natural raw material for cork stopper production and the
large increase in bottled wine.
[0004] In order to minimize the consumption of natural cork, stoppers have been proposed
with cork washers about 1 centimetre thick on the end in contact with the wine, and
the rest of the stopper produced from a compound or agglomerate composed of cork shavings
soaked in a resin matrix.
[0005] Such stoppers, used for both mushroom shaped corks for champagne and similar wines,
or in flat-topped form for still and sparkling wines, are composed of an agglomerate
portion which is suited to the pressure of the carbon dioxide that counters the torsion
action during uncorking and the compression of the cage in the case of mushroom shaped
corks, and the corkscrew action in the case of flat-topped corks.
[0006] On the other hand, the lower part of the stopper glued to the former part is generally
composed of two superimposed natural cork washers, suited to the radial compression
caused by the bottle neck and to easy uncorking action (being less rigid than the
external portion).
[0007] Such washers are also conceived to prevent any transfer of adhesive smell, and to
provide a different specific weight compared to the upper part to permit automatic
orientation in bottling equipment.
[0008] However, this solution has not proved very efficient since, in any case, it mainly
uses cork which has become quite rare, and because the resin matrix can be attacked
and corroded by the presence of acid vapours (considering that in certain wines, the
pH drops to values of 2.5) it tends to release organic derivates that modify the organoleptic
characteristics of the wine.
[0009] To prevent the aforesaid drawbacks, other stoppers have been proposed in synthetic
materials, mainly plastic, but which have involved different problems, either for
their poor structural aptitude or for their excessive rigidity, and therefore problems
with uncorking or imperfect sealing capacity.
[0010] Therefore, the Applicant decided to consider producing stoppers in a synthetic material
able to replace stoppers made from cork or cork agglomerate and washers, suitable
for any type of glass bottle and for any bottle content.
[0011] Therefore the aim of the present invention is to produce a stopper in synthetic material
that presents the structural characteristics that make it suitable for uncorking action,
and at the same time, that presents the necessary sealing characteristics.
[0012] Another aim of the present invention is that of producing a synthetic stopper having
dimensions suited to pre-existing bottling equipment.
[0013] Furthermore, the aims of the present invention also include the need for providing
a synthetic stopper that can be used in the various corking configurations required
by different types of wine and glass bottles.
[0014] Another aim of the present invention is to produce a stopper for glass bottles suitable
for any other contents apart from wine.
[0015] This and the other aims according to the present invention are achieved by a synthetic
stopper for glass bottles as set forth in claim 1.
[0016] Further characteristics according to the invention are described in the depending
claims.
[0017] The synthetic stopper for glass bottles according to the present invention can be
obtained by coupling two portions of semi-expanded foam synthetic material having
differentiated deformation capacity, a first portion being plastic, and a second portion
being elastic.
[0018] The characteristics and advantages of the synthetic stopper according to the present
invention will be made clearer from the following description, provided as an example
but by no means limiting, with reference to the appended schematic drawings wherein:
Figure 1 is a schematic elevation view of the cross section of a stopper according
to the present invention;
Figure 2 is a schematic elevation view of the cross section of an embodiment variant
of the present invention;
Figure 3 is a schematic elevation view of the cross section of a different embodiment
variant of the present invention;
Figure 4 is a schematic elevation view of a different stopper according to the invention;
[0019] In reference to the figures, a synthetic stopper 10 for glass bottles is obtained
by coupling two portions of semi-expanded foam synthetic material having differentiated
deformation capacity, a first plastic portion P and a second elastic portion E.
[0020] The stopper that can be realised according to the present invention can be a mushroom-shaped
stopper destined for bottles of sparkling wine, champagne or similar types, or for
bottles having a widely flared shape such as the "champagnotte", or flat-topped stoppers
destined for sparkling or still wines in normal bottles such as the "bordelaise".
[0021] In a first embodiment illustrated in figure 1, the aforesaid difference in the deformation
capacity of the synthetic stopper 10 is obtained as a bi-component stopper by means
of co-injection or bi-injection or the double injection of two different materials,
such as a polyolefin 11 such as polyethylene PE for the plastic portion P, and an
elastomer material 12 such as styrene-butadiene copolymer or styrene-butadienestyrene
(SBS) for the elastic portion E.
[0022] In this manner, the necessary sealing capacity for the carbon dioxide and the resistance
to torsion during uncorking, plus the compression of the cage in the case of mushroom
shaped stoppers, or the corkscrew action in the case of flat-topped stoppers, are
obtained in the plastic portion P.
[0023] On the other hand, the elastic portion E that forms a single body with the previous
plastic portion P, is suited to the radial compression caused by the neck of the bottle,
and is easily uncorked since it is less rigid than the external portion.
[0024] It is noted that a free cork stopper having a diameter of approximately 28-29 mm
is reduced to a diameter of 17.5 -18 mm once it is inserted in the bottleneck.
[0025] It is also implicit that the materials used to produce the synthetic stopper must
not only be chemically and biologically suitable, but must also be suitable for contact
with food products.
[0026] In reference to figure 2, the synthetic stopper 10, in a single component form, is
just as easily produced with the methods described previously, using a same material
13, but having a different density in the semi-expanded foam. In any case the difference
in the specific weight permits perfect orientation of the stopper with all types of
orientation equipment.
[0027] The mixing of the two different components 11, 12 or the single component 13 with
differentiated density in the transition zone (the central part of the stopper) provides
an excellent barrier against the entry of oxygen and a perfect seal to maintain the
carbon dioxide.
[0028] In an embodiment variant illustrated in figure 3, the stopper, which in the illustrated
example can be obtained as a single component 13, presents at least one cavity 14
that can be hollow or realised by means of an insert in a material 15.
[0029] This cavity can be used to measure the deformable capacity of the portion under examination,
in this case, the elastic portion.
[0030] In this manner it is possible to increase or reduce the rigidity of the portion,
according to necessity.
[0031] Furthermore, the cavity and/or insert can be realised in any type of stopper of any
form whatsoever, both in bi-component and single component materials.
[0032] In addition, the single component stopper can be realised in either a material that
is mainly or completely elastic, or in a material that is mainly or completely plastic.
In fact, in the latter case the presence of one or more cavities, either hollow or
with a soft insert or inserts, will provide the stopper with the necessary deforming
capacity and elasticity.
[0033] Figure 4 shows a mushroom shaped stopper, which in the example is realised using
the two materials 11, 12, but which can be either single component or having a cavity
and/or an insert, according to productive requirements.
[0034] Such mushroom shaped stopper realises as described the structural resistance necessary
to withstand uncorking torsion and the presence of the cage, adapting itself with
its elastic portion E to the deformation imposed by the reduced diameter of the bottle
neck.
[0035] In this last case it is possible to optimise the synthetic spumante or champagne
or similar stopper, maintaining the original size of the cork stopper, and therefore
obtaining the perfect adaptability of the stopper to existing bottling equipment,
as well as improving the sealing capacity of the elastic portion.
[0036] The cavity and any possible insert can be realised in any direction and position
that is technologically useful for achieving the structural aim for which they are
destined.
[0037] Therefore it is understood that as well as the embodiments illustrated and described,
the present invention can also be realised in all combinations of said embodiments.
1. Synthetic stopper for glass bottles characterised in that it comprises two coupled portions in synthetic material having differentiated deforming
capacity, a first plastic portion (P) and a second elastic portion (E).
2. Synthetic stopper according to claim 1, wherein said differentiated deforming capacity
can be obtained by means of a single component (13) or more semi-expanded foam materials
(11, 12, 15).
3. Synthetic stopper according to claims 1 or 2, wherein said differentiated deforming
capacity is obtained by means of a polyolefin component (11), preferably polyethylene.
4. Synthetic stopper according to claims 1 or 2, wherein said differentiated deforming
capacity is obtained by means of an elastomer component (12) preferably styrene-butadiene.
5. Synthetic stopper according to the previous claims, wherein said differentiated deforming
capacity is obtained by realising a cavity (14) inside the stopper, and/or an insert
(15) in semi-expanded foam material.
6. Synthetic stopper according to claim 2, wherein said differentiated deforming capacity
is obtained by means of a single component (13) having differentiated density.
7. Synthetic mushroom shaped stopper according to any one of the previous claims.
8. Synthetic flat-topped-stopper according to any one of the claims from 1 to 6.