EP1015198A1

EP1015198A1 - Process for the manufacture of corks and corks manufactured using this process

Info

Publication number: EP1015198A1
Application number: EP98905480A
Authority: EP
Inventors: Antoine Bernard Nunes
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-02-05
Filing date: 1998-02-03
Publication date: 2000-07-05
Also published as: NZ337062A; AU6105298A; CN1247495A; WO1998034769A1; IL131215A0; HUP0001725A3; FR2759014A1; FR2759014B1; HUP0001725A2

Abstract

The process for manufacturing corks comprises the steps consisting in: stacking and assembling, by means of a food glue (8, 9), sheets of natural cork (5, 6, 7) whose combined thickness corresponds to the height of the corks to be manufactured; punching the corks out of the assembled sheets, perpendicularly to their plane.

Description

Process for the production of cork stoppers and stoppers produced by such a process

The present invention relates to a process for manufacturing natural cork stoppers and to stoppers produced by such a process.

The corking of bottles containing wines for aging is carried out using natural cork stoppers, traditionally made from planks from cork oaks whose dismantling or emergence preceding dates from 9 to 11 years, cut in strips whose width corresponds to the height of the plugs and the thickness is at least equal to their diameter.

The corks are made by contractors who cut them out of each strip of natural cork with a cookie cutter.

To minimize the cost price of corks, the workshops of the manufacturers are usually located in regions with low labor costs, far from the cork oak plantations, which implies the costs of transporting the material but also makes it difficult to follow it from one end of the manufacturing circuit to the other.

In addition, during transport and during storage at the manufacturers, the cork is likely to be exposed to the weather or to dirt, leading to the formation of mold and odors which, if the caps are poorly cleaned later, will affect the quality of the wine.

The manufacture of caps is done also with a rather low yield of about 30%, and waste are recovered Fonne ^chipboard, unsuitable for coming into contact guard wines.

Certainly plugs chipboard provided at each end of a natural cork washer designed to prevent the wine from contacting ^the agglomerate have been proposed in the European patent applications EP-A-0100302 and EP-A- 0 481 155 but these caps have not, to the knowledge of the depositor, been adopted for the corking of bottles containing wines for laying down.

There has also been proposed in French patent application FR-A-2 636 264 a manufacturing process consisting in cutting the plugs from a cylinder of natural cork of great length. This method remains however very close to the aforementioned traditional method with its drawbacks.

Finally, it is customary to seal, using cork particles, the pores of natural cork stoppers, when the latter are liable to cause plugging faults. However, these particles can be found later in wine. which of course is not desirable. The present invention relates to a novel method _for manufacturing an corks, used for bottle corking containing wines for aging and a lower cost than natural cork stoppers made according to the conventional method described above.

The method according to the invention is characterized in that it comprises the steps consisting in:

- superimpose and assemble using food glue natural cork sheets whose added thicknesses correspond to the height of the caps to be manufactured,

- cut the plugs in the plates thus assembled. The invention also relates to a cork stopper, characterized in that it is constituted by at least two sections of natural cork arranged end to end and assembled using a food adhesive.

A stopper according to the invention can advantageously consist of three sections of natural cork arranged end-to-end and assembled using a food adhesive, the section of natural cork intended to come into contact with the wine preferably having a higher height. or equal to a third of the height of the stopper.

Thanks to the invention, it is possible to use cork originating from cork oaks whose thickness of the bark is less than the standard diameter of the plugs, and therefore less expensive. Cork production becomes easier to regulate.

In addition, the cutting of the plugs according to the invention can be carried out entirely automatically, with a more rational use of the material reducing the proportion of waste, in a factory close to the cork oak plantations, therefore without the aforementioned drawbacks. related to the cost of labor, the transport of cork and the monitoring of the material.

Other characteristics and advantages of the present invention will appear on reading the detailed description which follows, of a nonlimiting example of implementation of the method according to the invention, and on examining the appended drawing in which:

FIG. 1 illustrates the traditional method of manufacturing cork stoppers,

FIG. 2 represents a plug obtained by such a process,

FIG. 3 illustrates a process for manufacturing cork stoppers according to the invention, and

- Figure 4 shows a plug obtained by such a process.

There is shown in Figure 1 a strip of bark 1 of cork oak, used for the manufacture of natural cork stoppers according to the traditional process. The bark strip 1 has a crust 2 on its upper face, and its width is equal to the height of the plugs to be produced. The latter is standardized, usually chosen to be 38, 45, 49 or 52 mm.

The plugs are successively cut with a cookie cutter by means of a machine called a tubeuse, comprising a cutting tube 3 cylindrical of revolution, sharpened at one end, and driven in rotation about its axis of symmetry.

The relative displacement of the cutting tube 3 and the bark strip 1 is carried out under manual control, and the manufacturing tolerances are usually more or less 0.5 mm for a nominal diameter of 2 mm.

The cutting tube 3 must be as thin as possible so that its external diameter is less than the thickness of the bark strip 1. Due to its thinness, the cutting tube 3 is subject to erosion and ovalization, causing an increase in manufacturing tolerances.

FIG. 2 shows a plug 4, manufactured by the traditional method described above, associated with a reference frame of orthogonal axes X, X and X.

The axis corresponds to the longitudinal axis of the plug. The thickness of the bark strip 1 is measured along the X axis.

During the capping operation, the plug 4 is compressed radially until its diameter is reduced to approximately 15 mm, which corresponds to approximately 65% of its nominal diameter.

Once left in place in the neck of the bottle, the stopper 4 tends to resume, by elasticity, its nominal diameter.

The standardized diameter of a neck being 21 mm, therefore less than the nominal diameter of the plug 4, the latter does not return to its nominal diameter but remains compressed radially in the neck, which makes it possible to obtain a hermetic closure.

The time required for the plug 4 to pass from a diameter of 15 mm to a diameter of 21 mm (which corresponds to 87.5% of its nominal diameter) is of the order of ten seconds.

This duration can constitute a factor limiting the rates of the bottling chains, because the bottles cannot be laid down until the corking is not hermetic.

We will now describe with reference to Figures 3 and 4 an example of implementation of the method according to the invention. We start from cork boards which are boiled, sorted, peeled, straightened and then cut into rectangular plates 5, 6 and 7 whose sides have the same dimensions, and whose added thicknesses correspond to the height of the plugs 10 to be produced.

To optimize the production as a function of the height of the plugs to be produced, it may prove advantageous to cut into its thickness a cork board if it is thick, to form two boards of lesser thickness.

These plates 5, 6 and 7 are superimposed and assembled, after having been coated with a food adhesive known in itself, to form a block of parallelepiped cork 11.

The layers of food glue have been designated by the references 8 and 9 in FIG. 3.

Any non-toxic glue which has sufficient adhesion to withstand tensile forces when uncorking can be used as food glue.

The plates 5, 6 and 7 are assembled, for example, hot and under pressure.

It should be noted that the production of the cork block 11 by assembling several plates 5, 6 and 7 individually cleaned beforehand allows, for an equal volume of cork, better elimination of impurities than in the prior art, because the cork surface exposed to cleaning agents is superior.

After cutting, each stopper 10 is constituted in the example described by three sections of natural cork coming respectively from the plates 5, 6 and 7, arranged end-to-end and assembled by the layers 8 and 9 of food glue.

The cork cells have substantially the same orientation in each plate 5, 6 or 7 of the cork block 11 as in the bark strip 1 described with reference to FIG. 1, since each plate is obtained by cutting a sheet of natural cork just like the bark tape 1.

Referring to the aforementioned reference frame of axes X, X and X, it can be noted that each plug 10 according to the invention is cut with its longitudinal axis parallel to the axis X, that is to say that there n is not cut in the thickness of the cork board using a cutting tube oriented parallel to the plane of the board as in the prior art, but using a cutting tube oriented perpendicular to the plane of the board. As a result, the orientation of the cork cells is different in the plug 10 and is more advantageous.

Indeed, after radial compression, the plug 10 returns more quickly by elasticity to its nominal diameter and the time required to obtain a hermetic closure is therefore reduced.

Comparative tests were carried out with cork test pieces of a given volume, some of which consist of natural cork cubes produced by cutting the bark and others of cork blocks 11 in accordance with the invention.

The cork test pieces came in one piece along the X and X axes, to simulate the radial compression of the known plugs 4, and the other test pieces along the X and X axes to simulate the radial compression of the plugs 10 along the 'invention.

On the one hand, it has been observed that the time necessary for the test pieces compressed along the X and X axes to resume by elasticity a volume equal to 87.5% of their initial volume, after compression having reduced their volume to 65% of the initial volume , was approximately twice as much as that necessary for the test pieces compressed along the axes X and X_, and on the other hand that the force to be exerted to compress the plugs radially 10 was less than the force to be exerted to compress the plugs 4 radially, this which results in less degradation of the cell structure of cork.

The cutting of the plugs 10 in each cork block 11 is easily automated and can be carried out with better efficiency and lower manufacturing tolerances than in the prior art. One can also use thicker cutting tubes, therefore more resistant and less likely to ovalize, because the thickness of the cutting tubes is no longer limited by the thickness of the bark.

It is advantageously possible to use several cutting tubes arranged side by side to cut several plugs 10 simultaneously in a cork block 11, in particular more than twenty-five plugs 10, for example thirty plugs 10, the relative displacement of the cutting tubes and cork block 11 is preferably carried out under automatic control and no longer under manual control as is the case with the traditional process.

Thanks to the invention, it is possible to produce plugs with a nominal diameter of 24.2 mm for example with a tolerance of more or less 0.2 mm only. The possibility of producing plugs 10 with a nominal diameter of 24.2 mm makes it possible to improve the quality of the plugging, with identical return time. Each plate 5, 6 or 7 preferably has a thickness less than or equal to 24 mm, which makes it possible to use natural cork which is thinner, and therefore less expensive than that used for the manufacture of stoppers according to the traditional process.

Preferably, the thickness of the section of natural cork intended to come into contact with the wine is chosen so that the wine cannot reach the food adhesive, and the height of this section is for example equal to at least a third the height of the plug 10.

As explained above, cork can be cleaned in better conditions and in this way we reduce the risk of mold formation which can impregnate odors and which can affect the quality of the wine.

In addition, it is possible to vary the cork qualities of each of the plates 5, 6 and 7 and thus choose for the production of the natural cork section intended to come into contact with the wine a better quality cork.

By playing on the qualities of cork of each of the plates and the relative arrangement of the latter, it is still possible to avoid having to carry out operations for clogging the pores of the cork, and thus eliminate the risk that particles of cork coming from this clogging is found in the wine.

Of course, the invention is not limited to what has just been described.

In particular, it does not depart from the scope of the invention by superimposing any number of natural cork sheets, greater than or equal to two.

Claims

REVE DICATIONS

1 - Process for manufacturing cork stoppers, characterized in that it comprises the steps consisting in:

- superimpose and assemble by means of a food container (8,9) natural cork sheets (5,6,7) whose added thicknesses correspond to the height of the plugs (10) to be manufactured,

- cut the plugs (10) in the plates thus assembled, perpendicular to their plane.

2 - Method according to claim 1, characterized in that the plates (5,6,7) are three in number.

3 - Method according to one of claims 1 and 2, characterized in that the assembled plates (5,6,7) form a rectangular block (11) whose dimensions allow the cutting of at least twenty-five plugs ( 10), preferably thirty. 4 - Method according to any one of claims 1 to 3, characterized in that the plugs (10) are cut simultaneously.

5 - Cork stopper, characterized in that it comprises at least two sections (5,6,7) of natural cork arranged end-to-end and assembled by means of a food glue (8,9), each section of natural cork (5,6,7) having been cut from a natural cork board by means of a cutting tube oriented perpendicular to the plane of said board.

6 - Cork stopper according to claim 5, characterized in that it consists of three sections of natural cork (5,6,7) arranged end-to-end and assembled by means of a food adhesive, the section cork intended to come into contact with wine having a height greater than or equal to one third of the height of the cork (10).

7 - Stopper according to one of claims 5 and 6, characterized in that each section of natural cork has a height less than 24 mm.