Capsule having a membrane and method for preparing a nutritional product
A capsule for preparing a nutritional product in a device adapted to supply liquid into the capsule is disclosed. The capsule includes at least one compartment for providing nutritional ingredients for the preparation of the nutritional product in combination with the supplied liquid, and the compartment includes a liquid impermeable membrane forming a release side of the compartment. The capsule further includes at least one relief element. Also disclosed is a membrane for use in the manufacture of said capsule. Also disclosed are methods of producing and using the membrane and capsule.
1. A capsule for preparing a nutritional product in a device configured to supply liquid into the capsule, the capsule comprising:
at least one compartment for providing nutritional ingredients for the preparation of the nutritional product in combination with the supplied liquid,
wherein the at least one compartment comprises a liquid impermeable membrane forming a release side of the at least one compartment, the liquid impermeable membrane configured to release the nutritional product from the at least one compartment, and
wherein the capsule further comprises at least one relief element protruding from an opening wall, wherein the at least one relief element is tooth shaped comprising a slanted surface that forms a tip at a first end of the slanted surface, and a second end of the slanted surface is opposite from the first end and is more distant from the liquid impermeable membrane than the tip, wherein the at least one relief element further comprises a base surface connecting the slanted surface to the opening wall, and wherein the at least one relief element comprises a surface perpendicular to the liquid impermeable membrane and extending between the base of the relief element and the tip of the relief element,
wherein the liquid impermeable membrane is free of an aluminium layer and comprises a first polymer layer and a second polymer layer being connected to each other at a respective surface of contact, wherein the first polymer layer comprises a precut and wherein the second polymer layer is free of a precut or weakened line or zone, and
wherein the relief element is positioned to overlap the precut in an axial direction perpendicular to a plane of the liquid impermeable membrane, the precut positioned such that a first end of the precut overlaps the at least one relief element and a second end of the precut does not overlap the at least one relief element when viewed along the axial direction.
2. The capsule according to claim 1 , wherein the first polymer layer has a puncture breaking load higher than a puncture breaking load of the second polymer layer and/or wherein the first polymer layer has an elongation at break higher than an elongation at break of the second polymer layer.
3. The capsule according to claim 1 , wherein the first polymer layer comprises polyethylene tetraphthalate or polyamide.
4. The capsule according to claim 1 , wherein the first polymer layer has a thickness between 5 and 80 μm.
5. The capsule according to claim 1 , wherein the second polymer layer comprises polypropylene.
6. The capsule according to claim 1 , wherein the first and the second polymer layers are adhered to each other to be connected to each other at surfaces of contact.
7. The capsule according to claim 1 , wherein the precut comprises a rectilinear slit or a cross-shaped slit.
8. The capsule according to claim 7 , wherein the precut in the first polymer layer is configured to act as a valve in association with the second polymer layer.
9. The capsule according to claim 1 , wherein the precut has a length between 2 and 20 mm and a width between 0.05 and 0.5 mm.
10. The capsule according to claim 1 , wherein the liquid impermeable membrane comprises a plurality of precuts which are uniformly and equidistantly distributed on the liquid impermeable membrane.
11. The capsule according to claim 1 , wherein the liquid impermeable membrane is positioned in the capsule such that the first polymer layer is positioned on an internal side of the at least one compartment and the second polymer layer is positioned on an external side of the at least one compartment.
12. The capsule according to claim 1 , wherein the capsule comprises an additional liquid impermeable membrane positioned to close an inlet side of the at least one compartment.
13. The capsule according to claim 1 , wherein the liquid impermeable membrane is gas impermeable.
14. The capsule according to claim 1 , wherein the second polymer layer has a thickness between 2 and 50 μm.
15. The capsule according to claim 1 , wherein the capsule comprises a body made of injected or thermoformed polymer.
16. The capsule according to claim 1 , wherein the capsule comprises a body, the body partially defines the at least one compartment and comprises a product outlet, the liquid impermeable membrane is sealed onto an inner circumferential edge of the body to close the release side of the at least one compartment of the capsule upstream of the product outlet.