ES2355805T3 - SOLID-LIQUID EXTRACTION PROCEDURE APPLIED TO CORK PRODUCTS. - Google Patents

Abstract

Solid extraction procedure applied to cork products for their decontamination, characterized in that it comprises the following stages: a. Put the cork product in an airtight container, b. Load the airtight container with water so that the cork product is completely submerged in that liquid, c. Apply a relative pressure of up to 10,000 pascals (10 bar) on the surface of the liquid, for one to 3600 seconds, using an appropriate gas, d. Release the pressurizing gas until the pressure inside the vessel reaches atmospheric pressure, e. Reduce the temperature inside the container, by means of an appropriate vacuum pump, until a relative pressure of up to -100000 pascals (-1 bar) is reached, for a period of time from 1 to 3600 seconds, f. Cause the vessel to return to atmospheric pressure.

Description

1 - OBJECT OF THE INVENTION

 The invention relates to the decontamination of cork products produced by means of a solid-liquid extraction process based on the successive application of pressure changes on a liquid surface in which the cork is submerged, which causes the contraction and the expansion of the cork, thus causing the release of contaminants trapped inside the cork.

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2 - STATE OF THE TECHNIQUE

 Cork is a natural porous product that contains on its surface, and within it, a diversity of pollutants derived from its vital experience in the forest that, in contact with liquids, can cause organoleptic changes in those liquids. fifteen

 In recent years, a variety of procedures have been developed and applied in an attempt to remove such contaminants. The existing procedures are based on the immersion of cork in disinfectant baths, alternated with centrifugation stages. Due to the operating conditions, these procedures do not eliminate all contaminants, namely those trapped inside the cork, which can subsequently cause organoleptic changes in the liquids with which the cork product will contact.

 In 1993, a thermochemical process for the expansion of the cork was patented (document PT 101215 of 11 of 3 of 1993) using a pressurized system (relative pressure from 980000 to 2940000 pascals (from 9.8 to 29.4 bar)) where the cork it is immersed in the presence of some organic solvents namely methanol, ethanol, formic acid, dichloromethane or chloroform. 25

 Although some features of the previous patent are similar to those of the present invention, its subject matter is different since it aspires to achieve material expansion of the cork that is not related to decontamination.

 Water was found to be an appropriate liquid for use in the decontamination process, which is an advantage in view of its availability with a substantial reduction in the final cost of the decontamination process.

3 - DETAILED DESCRIPTION OF THE INVENTION

The applicant has found that this problem of incomplete decontamination of cork products could be solved through a hydrodynamic procedure whereby the cork to be treated is placed in an airtight container and subsequently submerged in water that should be placed at a temperature which varies from 20ºC to 200ºC.

 Then, a relative pressure of up to 10,000 pascals (10 bar) is applied on the surface of the liquid, for 1 to 3600 seconds, using any kind of gas or gas mixture. Then, the gas 40 is released until the pressure of the vessel reaches the atmospheric pressure again. Therefore the pressure is reduced by means of an appropriate vacuum pump until a relative pressure of up to -100000 pascals (-1 bar) is reached. After being at this reduced pressure for 1 to 3600 seconds, the system is caused to return to atmospheric pressure.

 These differential pressure cycles are repeated several times until the purity of the desired cork is reached. A simple experimentation will establish the number of cycles required.

 Those skilled in the art will understand what changes can be made to the process of the invention, which should be understood as being encompassed within the scope of the appended claims.

Claims (4)

 1. Solid extraction procedure applied to cork products for their decontamination, characterized in that it comprises the following stages:  to. Put the cork product in an airtight container,  b. Load the airtight container with water so that the cork product is fully submerged in that liquid,  C. Apply a relative pressure of up to 10,000 pascals (10 bar) on the surface of the liquid, for one to 3600 seconds, using an appropriate gas,  d. Release the pressurizing gas until the pressure inside the vessel reaches atmospheric pressure, 10  and. Reduce the temperature inside the vessel, by means of an appropriate vacuum pump, until a relative pressure of up to -100000 pascals (-1 bar) is reached, for a period of time from 1 to 3600 seconds,  F. Cause the vessel to return to atmospheric pressure.  fifteen  2. Method according to the preceding claims characterized in that the gas used to apply pressure on the surface of the decontamination liquid is air, or a gas other than air or a mixture of gases.  3. Methods according to the preceding claims characterized in that the treatment cycle is repeated up to 100 times.