In-mould labelled capsule for beverage preparation

1. A beverage preparation capsule defining a closed chamber for enclosing a mass of soluble and/or extractable food material, for use in a beverage preparation machine, comprising:

a capsule body comprising capsule body walls comprising side walls, the capsule body walls further comprising a bottom wall having a dispensing opening, the capsule body walls comprising an injection-moulded oil-based or biomass-based thermoplastic material, selected from the group consisting of: polypropylene (PP), polyethylene (PE), polystyrene (PS), polycarbonate (PC), polyethylene terephtalate (PET), and polylactic acid (PLA);

a gas and moisture impermeable top membrane, pierceable by an injection member of the machine which is adapted to inject an extraction liquid under pressure inside the chamber;

a gas and moisture impermeable bottom membrane sealed inside the capsule body near the bottom wall; and

a member adapted to open the chamber by relative engagement with the bottom membrane under the effect of the liquid pressure increase in the chamber during injection of the liquid;

the inside or outside surface of the capsule body is at least partially covered by a gas-impermeable label permanently attached by in-mold labelling to the capsule body wall, the label having a tri-dimensional shape such that the labelled capsule is gas and moisture tight,

the capsule body walls comprise a circumferential step directed inwardly, which is located between the side and bottom walls,

the external diameter of the bottom membrane is greater than the inside diameter of the label in the circumferential step, creating an overlap between the bottom membrane and the label in the circumferential step.

2. The capsule according to claim 1 , wherein the label covers the outside surface of the capsule body side walls, and the outside surface of the step.

3. The capsule according to claim 1 , wherein the label covers the outside surface of the capsule body side walls, the outside surface of the step, and the outside surface of the body bottom wall.

4. The capsule according to claim 1 , wherein the overlap is between 1 and 3 mm wide.

5. The capsule according to claim 1 , wherein the step is horizontal relative to the vertical symmetry axis of the capsule.

6. A process for making a body of a beverage preparation capsule comprising the steps of:

providing a gas and moisture barrier flat label having a general shape of an arc segment;

positioning and then forming the flat label around a core having a frusto-conical shape, into a frusto-conical label band;

positioning the label band inside a mold and closing the mold; and

injecting a thermoplastic material inside the mold so as to form a one layer thermoplastic capsule body which is labelled with the label, wherein the capsule body comprises side walls, a bottom wall open with a dispensing opening, and such that the label covers the inside or outside surface of the capsule body side walls.

7. The process according to claim 6 , further comprising punching a small apex of the label band to deform the label band inwardly and create an inward step edge.

8. The process according to claim 7 , wherein the label comprises fringes on the smallest edge of the arc segment, so that the punching bends the fringes inwardly, creating at least partial overlaps between adjacent fringes.

9. The process according to claim 8 , wherein the fringes are located tangentially perpendicular relative to the edge of the arc segment.

10. The process according to claim 8 , wherein the fringes are located tangentially oblique relative to the edge of the arc segment.