Sealed flexible cartridge

Abstract

The present invention relates to a sealed flexible cartridge, designed to be extracted under pressure, containing a beverage-forming substance for the preparation of a beverage. The cartridge has first and second sheets of circular, oval or polygonal shape which leave between them a space for the substance and are welded together around their periphery. The first sheet is made of a material chosen from filter paper, a non-woven material and a semi-rigid material and the second sheet is made of a material chosen from filter paper, a non-woven material and a composite. The first sheet is such that it allows water at atmospheric pressure to pass through it or by piercing and the second sheet is such that it allows water to pass through it only if an overpressure of between 0.1 and 3 bar is achieved during extraction from the cartridge.

What is claimed is:  
     
         1 . A sealed cartridge comprising first and second sheet materials joined to form a space therebetween, and a beverage-forming substance for preparing a beverage located in the space between the sheets, with the first material designed to admit water into the cartridge for extraction of the beverage from the beverage-forming substance, and the second material having properties to retain the water or beverage in the cartridge until an overpressure of 0.1 to 3 bar is achieved, at which overpressure the second material will rupture to allow the extracted beverage to exit the cartridge.  
     
     
         2 . The cartridge of  claim 1  wherein the beverage-forming substance is roasted and ground coffee, soluble coffee, a chocolate beverage forming substance or a mixture thereof.  
     
     
         3 . The cartridge of  claim 1  wherein the first sheet material is paper, a non-woven fiber or plastic material, or a semi-rigid material.  
     
     
         4 . The cartridge of  claim 1  wherein the first material is filter paper having a density of 15 to 30 g/m2 and a thickness between 0.1 and 1 mm or of a non-woven fiber or plastic material having a density of between 20 and 100 g/m2 so hat it will permit water to enter the cartridge by gravity flow.  
     
     
         5 . The cartridge of  claim 1  wherein the first material is aluminum having a thickness of 20 to 100 microns and is configured to allow puncturing by piercing means in order for water to be admitted into the cartridge.  
     
     
         6 . The cartridge of  claim 1  wherein the second material is paper, a non-woven fiber or plastic material, or a composite material, optionally containing weakened or prescored regions.  
     
     
         7 . The cartridge of  claim 6  wherein the second sheet is made of filter paper or of a non-woven fiber or plastic material having a sufficiently tight mesh to retain water in the cartridge until the overpressure is reached.  
     
     
         8 . The cartridge of  claim 6  wherein the second sheet includes weakened or prescored regions which open when the overpressure is reached.  
     
     
         9 . The cartridge of  claim 8  wherein the second material is an aluminum/plastic composite.  
     
     
         10 . The cartridge of  claim 7  wherein the second sheet includes a removable cover.  
     
     
         11 . The cartridge of  claim 1  wherein both the first and second sheets are made of a material that acts as an oxygen barrier so that no further packaging of the cartridge is required.  
     
     
         12 . The cartridge of  claim 1  wherein either or both of the first and second sheets are not made of a material that acts as an oxygen barrier so that a further packaging of the cartridge is required to prevent oxygen deterioration of the beverage-forming substance.  
     
     
         13 . The cartridge of  claim 2  wherein the first sheet material is paper, a non-woven fiber or plastic material, or a semi-rigid material, the second material is paper, a non-woven fiber or plastic material, or a composite material, optionally containing weakened or prescored regions, and the first sheet is welded to the second material.  
     
     
         14 . The cartridge of  claim 2  wherein the first and second sheet materials have a circular, oval, or polygonal shape and the substance is present in an amount of 5 to 10 grams.  
     
     
         15 . The cartridge of  claim 13  wherein the first and second materials are each made of filter paper.  
     
     
         16 . The cartridge of  claim 13  wherein the first and second materials each is a woven fiber or plastic material.  
     
     
         17 . The cartridge of  claim 13  wherein the first material is aluminum and the second material is one of a filter paper, filter paper with a cover, or a pre-scored plastic material.  
     
     
         18 . The cartridge of  claim 13  wherein the first material is filter paper or a non-woven fiber or plastic material, and the second material is an aluminum/plastic composite.