Precharged ground coffee capsule, method for its production and apparatus for implementing said method

A coffee capsule, comprising

• a container body forming in its upper portion an open end for receiving water and forming in its lower portion an opening for discharging coffee brew, the container body terminating at a position in proximity to said open end with an outwardly projecting radial flange;
• and
• further comprising a first wall being a separate part from said container body;
• and a second wall being a separate part from said container body;
• wherein
• said container body has a polygonal cross section;
• said container body is made of a liquid-impermeable material consisting of a first layer made of a metallic material, said first layer facing the exterior of said container body, and a second layer made of a thermoplastic material, said second layer facing the interior of said container body;
• said first wall is made of a single layer of liquid-permeable material;
• said second wall is made of a single layer of liquid-permeable material;
• said first wall is heat-welded to said second layer of said container body in its upper portion at said outwardly projecting radial flange, whereby covering said open end from an outside of said container body;
• and
• said second wall is heat-welded to said second layer of said container body in its lower portion, whereby covering said opening from an inside of said container body.