Portioned package for espresso machines

Abstract

Truncated-cone-shaped capsules of plastic can have a lower construction height than the widespread aluminium capsules for creating an espresso, in order to avoid the hot water injection needles penetrating into the portioned package of plastic and bonding. By way of this, a greater quantity of heated water at an increased pressure prevails outside the truncated-cone-shaped capsule with its conical side wall and the circumferential flange projecting circumferentially therefrom. This necessitates greater demands on the sealing of the truncated-cone-shaped capsule with respect to the brewing chamber, in which the capsule is introduced. It is therefore suggested to attach a seal in each case on the flange on the head-part-side surface as well as the opposite membrane-side surface.

1 . A portioned package which under pressure in espresso machines is suitable for extraction of coffee and which contains a substance for preparing a drink, in particular of roasted and ground coffee, consisting essentially of a truncated-cone-shaped capsule of plastic with a conical side wall, of a head part integrally formed on the small diameter and having a sieve plate integrally formed as one piece for the piercing-free feed of an extraction fluid, and of a circumferential flange on the wider end of the conical side wall, said flange projecting from the conical side wall, wherein the flange has an annular, head-part-side surface and an oppositely lying annular membrane-side surface, onto which a destructible membrane is welded and moreover the head-part-side surface is provided with a circumferential seal, wherein a further circumferential seal is attached on the circumferential flange at the membrane side. 
     
     
         2 . A portioned package according to  claim 1 , wherein the head-part-side seal as well as the membrane-side seal are formed from a multitude of recesses which are arranged next to one another, do not communicate with one another and are separated from one another by webs, wherein the recesses form retention spaces and the webs form multiple sealing locations. 
     
     
         3 . A portioned package according to  claim 2 , wherein the webs and the recesses of the seals form an essentially honeycombed structure. 
     
     
         4 . A portioned package according to  claim 2 , wherein the recesses have a concavely bent or concavely truncated-pyramid-like structure. 
     
     
         5 . A portioned package according to  claim 1 , wherein the flange is provided with a peripheral centring bead, and the circumferential seal is arranged at least in a part region between the centring bead and the side wall. 
     
     
         6 . A portioned package according to  claim 1 , wherein the flange at the membrane side is provided with a circumferential seal only in the peripheral region, and the region close to the centre serves as a seal-free welding surface. 
     
     
         7 . A portioned package according to  claim 6 , wherein the head-part-side circumferential seal and the membrane-side circumferential seal at least partly overlap in a projection in the radial direction. 
     
     
         8 . A portioned package according to  claim 1 , wherein the webs of the circumferential, membrane-side seal serve as energy conducting means for ultrasound welding the destructible membrane.