Sealed flexible cartridge

摘要

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.