Coffee capsule

A capsule which under pressure in expresso machines is suitable for extraction of coffee and which may contain roasted and ground coffee, comprising

• a truncated cone-shaped capsule body of thermoformed plastic having
• a conical side wall, the wider end of the side wall defining an outlet side of the capsule and the narrower end of the side wall defining an inlet side of the capsule;
• an outwardly directed circumferential first flange on the wider end of the conical side wall providing a sealing area towards a brewing chamber of an expresso machine;
• and
• a circular inlet opening on the narrower end of the conical side wall;
• the capsule further comprising
• a destructible outlet sealing membrane being attached to the first flange and closing the outlet side of the capsule body;
• and
• a destructible inlet sealing membrane closing the inlet opening of the capsule body and being attached to the inside of the capsule body;
• wherein
• the capsule body further comprises a circumferential centering ramp at the narrower end of the conical side wall, which translates into an inwardly directed circumferential second flange forming the circular inlet opening, the circumferential centering ramp designed to align the inlet sealing membrane with the inlet opening before welding it to the second flange;
• and
• wherein the inlet sealing membrane has a diameter larger than the outer diameter of the second flange, such that the circular edge of the inlet sealing membrane is able to bend upwards along the centering ramp and at least partially covers the centering ramp when welding it to the second flange, wherein the upwards bend circular edge forms a heat protecting layer between a hot sealing tool and the centering ramp during welding the inlet membrane to the second flange.